United States
Environmental Protection
Agency
Office of Research and     Office of Solid Waste and
Development • Risk Reduction Emergency Response
Engineering Laboratory
                              September 1989
Forum on Innovative Hazardous
Waste Treatment Technologies:
Domestic and International

Atlanta, Georgia
June 19-21,1989
Technical Papers

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                                 FOREWORD
   As a result of the high level of interest in innovative hazardous waste control
technologies, U.S. EPA's Office of Solid Waste and Emergency Response (OSWER) and
Risk Reduction Engineering Laboratory (RREL) jointly conducted this conference.  The
conference consisted of presentations of technical papers and posters by international
and domestic  vendors  of technologies for the treatment of waste, sludge,  and
contaminated soils at uncontrolled hazardous waste disposal sites.

   The purpose of the 21/£-day conference was two-fold:  to help introduce promising
international technologies through  technical paper  and  poster displays;  and to
showcase results of the U.S. EPA Superfund Innovative Technology Evaluation (SITE)
program technologies in  addition to other  domestic innovative  technologies.  Both
were aimed  at increasing awareness of the user community in technologies ready for
application.

   This compendium  does not include  all  papers  that were presented; only those
that were made available by authors and their institutions  are included.   A
publication containing one-page abstracts of each presented paper will be available
from EPA's  Center for Research Information (CERI) in the Fall of 1989.  Subsequent
inquiries may. be addressed to CERI, P.O. Box 12505, Cincinnati, OH  45212.
      Although this document has been published by the U.S. Environmental
      Protection Agency,  it does not necessarily  reflect the  views of the
      Agency, and no official  endorsement should be inferred.  Mention of
      trade names or commercial products does not constitute endorsement or
      recommendation for use.

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                             TABLE OF CONTENTS

                                                                       Page

Experience with the Harbauer PBS Soil Cleaning  System	    1
  H.D. Sonnen, W. Groschel, M.  Nels, Harbauer GmbH

Remediation and Treatment of RCRA Hazardous Wastes by Freeze
Crystal 1 i zati on		   18
  James Heist, Freeze Technologies Corporation

Purification by Froth Flotation	   33
  Cas Mosmans, Mosmans Mineraaltechniek

Reverse Osmosis:  On-Site Treatability Study of Landfill  Leachate       41
at the PAS Site in Oswego, NY	
  Charles Goulet, Septrotech Systems Incorporated

Electro-Reclamation in Theory and Practice	   57
  R. Lageman, Geokinetics

Vacuum Extraction Technology, SITE Program Demonstration at             77
Groveland Wells Superfund Site, Massachusetts	
  James J. Malot, Terra Vac

UV/Oxidation of Organic Contaminants in Ground, Waste, and              92
Leachate Waters	
  David B. Fletcher, Eriks Leitis and Due H. Nguyen, Ultrox
    International

In Situ Steam/Air Stripping	  112
  Phillip LaMori and Jeff Guenther, Toxic Treatments Inc.

The Simplest Way to Clean Water	  116
  Ralf F. Piepho, The Piepho Corporation

Regional Biological Decontamination Centers for the Clean-up of
Contaminated Soil, Sludges and  Industrial Wastewaters	  124
  Hein Kroos, Biodetox GmbH

Biological Remediation of Contaminated Groundwater and Soil -
Concepts of Remediation and their Technical Application	  139
  M. Kastner, Technical University of Hamburg-Harburg
  K. Hoppenheidt and H.H. Hanert, Institute of Microbiology,
    Technical University of Braunschwieg Biocenter

The Holzmann System for In-Situ Soil Purification	  151
  Hans G. Bathus, Philipp Holzmann AG

Biological Regeneration of Contaminated Soil	  157
  Volker Schulz-Berendt, Umweltschutz Nord GmbH & Co.

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                       TABLE OF CONTENTS (Continued)
Seven Years Experience in Thermal Soil Treatment	 161
  Rudolf C. Reintjes and Cees Schuler, Ecotechniek bv

Contaminated Soil Remediation by Circulating Bed Combustion	 172
  Robert G. Wilbourn and Brenda M. Anderson, Ogden Environmental
    Services, Inc.

Residues from High Temperature Rotary Kilns and Their teachability.... 195
  Ronald Schlegel, W&E Environmental Systems

Recycling of Contaminated River and Lake Sediments Demonstrated by
the Example of Neckar Sludge	 231
  H. NuBbaumer and E. Beitinger, Ed. Zublin AG

Oxygen Enhancement of Hazardous Waste Incineration with the
Pyretron Thermal Destruction System	 241
  Mark Zwecker, Fred Kuntz and Gregory Gitman, American
    Combustion, Inc.

Process Description and Initial Test Results with the Plasma
Centrifugal Reactor	 263
  R.C. Eschenbach, R.A. Hill and J.W. Sears, Retech, Inc.

Superfund Innovative Technical Evaluation Findings and Conclusions.... 280
  Timothy E. Smith, HAZCON Engineering, Inc.

SITE:  Fixation of Organic and Inorganic Wastes/Intimate Mixing
Technique	 289
  Carl L. Brassow, J.T. Healy and R.A. Bruckdorfer, Soliditech,
    Inc.

Advanced Chemical Fixation of Organics and Inorganics/In-Situ
Treatment	 303
  Jeffrey P. Newton, International Waste Technologies

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     EXPERIENCE WITH THE HARBAUER PB3 SOIL CLEANING SYSTEM
     Dr.  H.D. Sonnen, W. Groschel, M. Nels
1. SUMMARY

The  system to  be  described  is  an  extractive  soil  washing
system, the  HARBAUER PB3, which since July  1987 has  been in
operation  at  the  former Pintsch  oil  refining  facility  in
Berlin.

To date 20,000  tons of soil  from the Pintsch  site  itself  and
from  other  selected  sites   has  been cleaned   by  the   unit.
Experiences and results  from these  soil  extraction operations
will  be described as well as future plans  for the  application
and use of the  technology.
 2.  INTRODUCTION

 Parts  of  the Pintsch site are heavily polluted from residues  of
 former used oil  refining activities.

 The primary pollutant groups which were found  in  both  soil  and
 ground  water  were:  Mineral  Oil,  Halogenated  Hydrocarbons,
 Polycyclic   Aromatic   Hydrocarbons    (PAHs),   Polychlorinated
 Biphenyls  (PCBs), Aromatic Hydrocarbons and Phenols.

 In  addition  Polychlorinated  Dibenzodioxine   and Dibenzofuran
 were  found at specific  locations.

  In order to control the immediate danger  and limit the release
  and spread of contamination through  dust  and  air emissions as

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well as further  contamination of the ground  water,  the Senate
of  Berlin  initiated  a clean-up  program in  the fall  of   1984
under  the  auspices  of  the  Senator  for  City  Planning  and
Environment (2).

THe  firm  KEMMER/HARBAUER was responsible' for the  majority of
the clean-up activities on  the  site.  Major activities included
(4):
  Demolition  of  contaminated  buildings,  stacks,  and
  equipment using maximum level protective clothing.
other
- Excavation of soil,  removal  of  existing tanks, and equipment,
  and  digging  out  and  removal   from  overflow  trenches  and
  ditches,  (work was carried out in maximum as well as in lower
  levels  of  protection  including  the  use  of  special  earth
  moving  equipment which was  equipped with  a  pressurized air
  filtered  cabin)

- Providing decontamination stations  and  protective clothing
  for all employees  and vehicles.

- Design,  building and operation  of  a ground  water treatment
  plant.

- Design, building and operation  of a  soil  cleaning plant.

The soil cleaning facility has  been  in  operation  since  July
 1987 and has,  in  the framework of a Demonstration project under
 the auspices of the Berlin Senators for  Building Construction,
 successfully cleaned 20,000 tons  of soil.

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EXCAVATION OF CONTAMINAITED SOIL
    SITE CLEAN-UP  IN  PROTECTIVE CLOTHING

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3.0  THE HARBAUER EXTRACTIVE SOIL CLEANING SYSTEM

The soil washing system developed by  HARBAUER  is the result of
a  scientific  research  program  in  combination  with years  of
practical experience on-site.  The  unit is capable  of cleaning
contaminated soil and  rubble  so that the cleaned  material can
be  refilled   on  site  and   is  suitable  for  further  un-
restricted/normal use.  The contaminant  is  washed out  of the
polluted material  and  carried away  in  the liquid/extractant
phase. The process  gases  and  effluent handling  systems  of the
soil   washing   facility    prevent    contaminant  from   being
transferred to water or air media.

Each soil washing technology has its own critical cut-off point
in  the small  particle size  range  where  the  process   can  no
longer effectively  treat  contaminated material. Those particle
sizes  smaller than  the cut-off  point cannot  be  economically
cleaned and are found in the  residual  sludges  from the washing
process. The  advantage  of  the HARBAUER technology is  that the
cut-off  point  is  at  15  urn,  which  means   that   not  only
scrap/metals, gravel and sand but also silt  can  be cleaned.
 3.1  DESCRIPTION OF THE PROCESS

 The principal process  steps of  the  HARBAUER system can be seen
 in  the flow diagram  of the  plant  (FIG.  1). The  facility  is
 divided into four  basic operations:

 - Soil preparation and extraction or  clean-up
 - Clean-up of process  waters
 - Treatment/dewatering of  remaining sludges
 - Removal and cleaning of  exhausted air  emissions

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In the  Soil  preparation/extraction  step  (process unit  1) the
contaminated  soil  and  rubble  is  screened  and  mixed  with
extractant then subjected to intense vibrations or oscillations
produced by the use of mechanical energy which set the material
in motion and free the contaminant  from the soil particles.  It
can then be  dissolved in the  liquid phase  thereby  forming  an
emulsion of contaminant with the extractant.  The effect of the
energy can be enhanced by the addition  of cleaning agents  ( eg.
biologically degradable detergents).

Through  multi-step rinsing,  separation and  dewatering opera-
tions the cleaned  soil particles are recovered from the  extrac-
tant  medium  and removed  as clean  product.  The  lower particle
size  limit  for separation is 15 urn and as such REPRESENTS THE
STATE OF THE ART FOR  SOIL WASHING.

Operational  costs and requirements for extraction,  separation
 and dewatering increase  disproportionately with  decreasing par-
 ticle size.  HARBAUER is  now investigating,  under a joint re-
 search  project with  the  Ministry  for  Research  and  Technology
 and the  City   State  of  Berlin  whether it  is  technically  and
 economically  feasible to  achieve   an even  lower particle size
 cutoff.

 Following the extraction step the  dislodged  pollutant  is  found
 partly as particles  and  partly  emulsified or dissolved in the
 water phase.  The  dissolved/emulsified  contaminants  are carried
 to  the  water  treatment  plant (FIG.  1, unit 2)  where  they are
 concentrated  out  using the following four  step process:
  -  Oil  Separation
  -  Flotation
  -  Desorption
  -  Filtration  and  adsorption on  activated carbon

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The contaminants removed during the water treatment process are
removed as oily sludges, flotation sludges and loaded activated
carbon.
The particulate contaminant is recovered together with the fine
particle sludge fraction (under 15 urn) and  is  dewatered with a
filter band  press.  (FIG  1,  unit  3). The  amount  of  residual
sludge is dependent upon the  particle  size  distribution of the
input material and  for  the  soils processed to date  is  between
5% and 10% of the input.
The degree of pollution of  the  residual sludge  is ultimately
determined by the  contaminants  in  question.  Low  solubility
contaminants   such   as  heavy  metals  enrich  the  sludge  phase
whereas high  solubility contaminants  ( organics eg., benzene )
result in moderate levels of sludge contamination.

The remaining sludge is currently landfilled but investigations
are underway  to other  more  suitable treatment  methods  (eg.
chemical, thermal,  solidification-).

Light materials in the soil such as tar, wood, roots  and char-
coal  particles  will  be separated  by upward  current  classi-
fication/fluidized  bed  sorting  and  screening  using   a  DSM
screen.

Because  of environmental  and worker  safety  reasons the  first
three  process steps, units  1-3,  have an  air  removal  system
which feeds the contaminated exhaust air directly into  the air
cleaning unit (unit 4). Air emissions are cleaned in a two step
process using wet scrubbers followed by activated carbon.
In this step  any separated volatile materials  are recovered as
solvent  mixtures with incineration as the indicated  method of
disposal.

In the event  that  a planned crushing  unit is  added it  will be

                               6

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necessary to have  a dry  air  cleaning system  (dust filter)  to
collect  emissions.  These  residues  could then  be  treated  by
solidification.
3.2  PROCESS FLOW CHART

The  flow  chart  for the HARBAUER process  is shown in FIGURE  2.
The  contaminated  soil is brought by  a  front end loader to  the
receiving  area after  which  it passes  through  an  over-sized
particle  screen where material larger than  60  mm is  removed.
This step separates materials  such as  debris,  wood,  and  other
miscellaneous  large objects  which  may,  depending upon  the type
and  level of contamination,  require  special disposal.

The  debris free soil is  then mixed with water in a blade washer
where lumpy material  is  broken up by  the  stirring  motion.  In
 the  same step  light material (wood particles, charcoal and tree
 roots)  are separated  out.   This  light  particle  fraction  is
 temporarily stored in containers.

 The majority of the material from the blade washer goes into a
 two  step  screening  process.  Material  from  the  first  screen
 (greater  than  5  mm) is rinsed, dewatered  and removed  as clean
 material.  The overflow from the  second  screen goes  into  the
 extraction unit  for  further treatment.  The washed-out  fine  ma-
 terial  greater than  15  urn  is concentrated in  hydroclyclone I
 and is  ultimately brought to the  extraction unit.

  The actual extraction of the  soil  occurs in a  specially deve-
  loped extraction  unit.  Here  a  forward  screw  is subjected to
  axial vibration, created by  an electronically  steered mechani-
  cal  energy  component.  In  this  extraction unit  the  particles
  between  15(im  and 5mm are  cleaned using mechanical  energy.  The
  soil particles are subjected  to an energy density sufficient to

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break the  bonds between  the  contaminant and  soil  particle so
that the contaminant  is  freed and dissolved  in  the extractant
(water)  phase.  The  frequency,  and amplitude of  the energy can
be varied  to optimize conditions  for the  individual  types of
pollutant  and soil  being treated.  The  extractant,   which is
generally water ( sometimes with  small  amounts of biologically
degradable  detergent),  is added  in  a  1:1  ratio to  the  soil
(1,3).

In the  next step the  material is washed in  a  countercurrent
sandtrap. Here the fine fraction < 130 urn and its extractant is
freed of any light material like wood, charcoal,  or tar using a
sieve and is carried to the fine particle wash.

The larger material (sand/fine gravel fraction) is dewatered in
sieve  III   and  sent  to   the  fluidized  bed sorter.  Here  the
contaminated "light" materials are floated out and removed from
the washing process by a screen.

The clean-up  of the  fine  particle  fraction occurs in a  five
step countercurrent  hydrocyclone.  Following the  hydrocyclones
the  dewatering  of   this  material  stream  together  with  the
sand/fine  gravel fraction  which  was  the   throughput  of  the
fluidized  bed sorter occurs  in  sieve IV.  Cleaned  material is
carried out by a conveyor belt.

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EXTRACTION UNIT AND HYDRAULICS
 MULTI-STEP HYDROCYCLONE UNIT

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The over flow of hydrocyclone unit  I  contains  the  fine  particle
fraction under 15(jm, in which the contaminant  may  in  some  cases
be  concentrated.  The  separation  of  these   solids  from  the
process  water   stream   is   accomplished  by  thickening.   The
sedimented sludge is then dewatered using a filter band press.

The solid free process water is  then  cleaned  together with  the
contaminated  ground  water.  The  ground  water/process   water
treatment plant  is  a  4  step process. First any  oil  layers  are
removed by an oil separator. This step is followed by flotation
where heavy metals and and  emulsified hydrocarbons are separa-
ted by addition of the appropriate chemical agents.

The primary pollutant group in ground water at the Pintsch site
is volatile  chlorinated  hydrocarbons.  To  achieve recovery  of
volatiles an air stripping step was added which  has  a recovery
efficienly of  approximately  99  %.  The  stripped volatiles are
recovered from the  air  stream  by activated carbon.  The carbon
is steam regenerated on-site.

The  last  step of  the water  treatment  process  consists  of a
series of filters including three sand  filters followed by six
activated  carbon  filters.  Input   to   the   filters   can  be
individually controlled  for selective  loading  depending  upon
the  contaminant  stream  in question.  Here  the remaining  trace
amounts of contaminant are  removed.  The cleaned process  water
is then recirculated through the soil cleaning process.

The cleaned groundwater is fed  into  the  adjacent waterway, and
must  therefore  be  monitored   to  ensure  that  it  meets  the
stringent standards for drinking water purity.
                               10

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4.0  CLEAN-UP RESULTS

To date the unit has treated soils from the following sites;

Site of former chemical production/refining companies,

- Waste oil refining facility
- Tar chemistry facility
- Paint fabrication facility

The primary pollutants found in these facilities were:

Hydrocarbons
Chlorinated Hydrocarbons
Aromatic and Polyaromatic Hydrocarbons
PCBs
Phenols    ,                     •   ,
 Sites of  former gas works,

 -  HKW Moabit,  Berlin
 -  Eisstadion Wilmersdorf, Berlin

 Primary  Pollutants  for  these  sites  were:

 Hydrocarbons
 Polyaromatic  hydrocarbons
 Phenol
 Cyanides
                                11

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Sites contaminated by Mercury

- Soil from the former chemical plant at Marktredwitz

The clean-up  results for  these  various sites  can be  seen  in
figures 3,4,5.
5.0.  FURTHER DEVELOPMENT

Using the outlined systematic solution  it  is possible to clean
soil  with   complex   pollutants   and  problematic  particulate
composition in such a way that the cleaned soil may be refilled
and reused.

We  now  have  experience  and  results from  a  relatively  broad
range of sites (  former chemical/physical facilities, gasworks,
and heavy metal contaminated soil). Nevertheless there is still
a need  for further  research  and  development to  evaluate  the
total picture for  abandoned  site  clean-up; in  light of  the
non-homogeneous nature of these  sites  and  the unique character
of each clean-up problem.

The actual potential  for  development lies in  the  treatment of
the fine and medium clay fraction  (material with particle sizes
under  15um)  and  in improving  the  separation,  clarification,
dewatering and transport aspects.

Based  on  the  positive results  of  the  FBI, PB2  and PB3  one
should  be able  to  assume that  at  the  end of  the  .current
development  phase  (  the final  development  of  the  PB4  )  one
should  have  a system  capable  of  handling  the  majority  of
abandoned  sites  in a  systematic way using  an environmentally
safe and economically  feasible technology.
                              12

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6.0  LITERATURE

(1) Sonnen, H.D.   Vorstellung   einer  Bodenwaschanlage,   in;
                   Abfallwirtschaft 18 (1987), S. 117 - 126.
(2) Woltmann, M
Die  Sanierung  des   Pintsch-Gelandes,   in:
Fortbildungszentrum Gesundheit-  und Umwelt-
schutz Berlin  e.V.  (Hrsg.):  Sanierung  kon-
taminierter Standorte  1985,  Seminar des FGU
Berlin am 23./24.09.1985, Wiesbaden, 1985.
 (3)  Sonnen, H.D.   Erfahrungen mit einer Bodenreinigungsanlage
     Klingebiel, S. in Berlin, in: Wolf, K-;  van  der  Brink,  J.;
                   Colon, F.J.;  (Hrsg.): Altlastensanierung'88.
                   Zweiter    internationaler  TNO/BMFT-Kongrefi
                   viber  Altlastensanierung  vom   11.04.
                   15.04.88,  Kluver  Academic Publishers,  Dord-
                   recht, Boston,  London,  1988,  S. 899 - 905.
  (4) Sonnen,  H.D.
     Groschel, W
 Erfahrungen mit einer Bodenreininigungsan-
 lage,  in:  Thome-Kozmiensky,  K.J.  (Hrsg.):
 Altlasten  2,  Fachtagung  Praxis  der  Altla-
 stensanierung  vom  01.11.  -  04.11.198.8,  EF-
 Verlag  fvir Energie und Umwelttechnik GmbH,
 Berlin, 1988,  S. 771 - 780.
                                13

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 xi—.contaminated soil/    r-
 NI—'demolition waste     L

 £—i biologically degradable
 N/  ^detergents           _
s—i contaminated qroundf
x/—' water             I
    oxidizing
 .	agents
(~J reducing
    agents

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Figure 2"- Block Diagram System HARBAUER
Groundwater- and Extraktive Soil Claening
on the former Pintsch Site ,Berlin
15

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    10000
          [ppml
                   [clean-up success]
                                                         100%
     0,01
           Aliphat.    Chlor.  '  Aromat.
                  Hydrocarbon*
                  PAH
              PCS
              I Input
  I Output
 i Clean-Op Success
Figure 3: Clean-Up Results for HARBAUER Soil Washing System
     (Origin of soil: former waste oil refinery and former paint
                manufacturing plant, respectively)
  100O-T-  	
                                         [clean-up success]
                                                       --80%
                                                       --60%
                                                         100%
                                                       --40%
                                                       --20%
       Petroleum Ether
            Extract
  PAH
Phenol
Total Cyanide
            ! Input
i Output   I"  I Clean-Up Success
Figure 4: Clean-Up Results for HARBAUER Soil Washing System
              (Origin of soil: former gasworks site)
                              16

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  1000 T
       [mg Hg/kg dry matter]
                  [clean-up success]
                           ...._._ 100%
                        2     '      3
                      Number of Sample
                        Average
           I Input
i Output
I Clean-up Success
Figure 5: Clean-Up Results for HARBAUER Soil Washing System
          (Origin of soil: former chemical plant site A)
        [mg/kg dry matter]
   1000 ^r
    100 i
                   [clean-up
                                 T 100%
          Aliphat.   Aromatic
            Hydrocarbons
         PAH
      PCS     Phenol
                                                        0%
HI Input E
• Output
I I Glean-up Success
w
 Figure 6: Clean-Up Results for HARBAUER Soil Washing System
           {Origin of soil: former chemical plant site B)
                               17

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             FREEZE TECHNOLOGIES CORPORATION

                   REMEDIATION AND TREATMENT OF
                       RCRA HAZARDOUS WASTES
                      BY FREEZE CRYSTALLIZATION
                              ABSTRACT

 Freeze crystallization is a general separations process used to remove pure
 components from solutions by crystallizing the materials to be removed.
 This process has been used for applications as diverse as organic chemical
 refining and fruit juice concentration, and is especially suited for treating
 hazardous wastes. This paper will illustrate how the process can be used
 in site remediation activities, including treating contaminated soils, where
 it can be used to recover valuable by-products from RCRA and other
 industrial waste streams, and the  basis for its utility in mixed (hazardous
 and radioactive) wastes.

 Freeze Technologies Corp. has built a mobile site remediation prototype
 commercial plant to demonstrate the field remediation aspects of this
 technology. The capacity of the unit is nominally 10 gpm of ice production
 from a leachate or groundwater, at 90% water recovery. It is contained in
 two modules that are transported  on standard low-boy trailers, and
 requires less than 1 week to set up.

 Freeze crystallization has several advantages  for remediation and waste
 recovery applications. First, it is  a very efficient volume reduction process,
 producing a concentrate that has no additional chemicals added to it - if
 disposal in a hazardous waste landfill, or incinerator destruction is
 required this will reduce these costs substantially. When a large fraction
 of the solvent (usually water),  is removed from a waste, the remaining
 impurities often begin to crystallize as well - they are often sufficiently
pure to have by-product value for resale.  Processing costs with freezing
are generally low, ranging from $.03 to $.15 for 40 and 5 gpm plants,
respectively.
                                   18

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            FREEZE TECHNOLOGIES CORPORATION

                     FREEZE PRO CESS DESCRIPTION

     The basic operation involved in freeze crystallization is the
production of crystals by removing heat from a solution. Crystals
produced in this manner invariably have very high purities. Once small,
uniform crystals have been produced, they must be washed to remove
adhering brine. The brine is recycled to the crystallizer, so that as much
solvent as desired can be recovered.  The pure crystals are usually melted
in a heat-pump cycle, which further improves the energy efficiency of the
process.
     When one or more of the solutes exceeds its solubility additional
crystal forms are produced, but they are formed separately from each
other and from the solvent crystals.  Since in most waste applications the
solvent is water, and ice is always less dense than the solution and the
solutes usually more dense, it is easy to separate these crystals by gravity.
     A freeze crystallization process is then composed of the following
components, as illustrated in the process flow diagram of Figure 1:
            - a CRYSTALLIZER, where heat is removed to lower the
              temperature of the material to the freezing temperature of
              the solution (usually crystallizing the solvent first);
            - a EUTECTIC SEPARATOR to segregate the crystals of solvent
              and solute into different streams, so that each can  be
              recoverd in pure forms;
            - CRYSTAL SEPARATOR/WASHERS that function to remove the
              crystals from the mother liquor in which they are slurried,
              and to wash adhering brine to very low levels so that the
              recovered crystals have high purity;
            - a HEAT-PUMP REFRIGERATION CYCLE to remove refrigerant
             vapor from the crystallizer, and compress it so that it will
              condense and give up  its heat to melt the purified  crystals;
            - HEAT EXCHANGERS are used to recover heat from the cold
              effluent streams, improving the heat efficiency of the
              process.
            - DECANTERS and STRIPPERS are required in some processes
              to remove volatile materials and/or refrigerant from the
              effluent streams before discharge;
            - appurtenant UTILITIES, CONTROLS, ELECTRICAL SWITCH
              GEAR, PUMPS AND PIPING are required to implement the
              freeze process in a continuous, closed system.
                                 19

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              FREEZE TECHNOLOGIES CORPORATION

      The design, operating characteristics, capabilities and limitations are
 determined largely by the type of crystallizer that is used, of which there
 are three basic choices:
            1) INDIRECT CONTACT, using a scraped surface or similar heat
              exchanger that will crystallize by removing heat through the
              heat transfer surface.
            2) TRIPLE POINT crystallizers use the solvent as the refrigerant
              at its triple point (where solid, liquid, and vapor phases are
              all in equilibrium).  For instance, with aqueous systems, the
              triple point occurs at less than 3 mm Hg. absolute pressure
              at 30 degrees F, or below.
            3) SECONDARY REFRIGERANT freezing uses an immiscible
              refrigerant that is  injected directly into the process fluid,
              and  evaporates at several hundred to several thousand
              times the vapor pressure of the solvent.
      The third option offers a number of advantages in treating hazardous
 wastes, resulting in a less expensive process that is inherently capable of
 producing higher quality effluents  and effecting a greater  reduction of the
 final volume.
                    10 GPM REMEDIATION PROTOTYPE

      The freeze crystallization process that has been accepted into the
EPA's Superfund Innovative Technologies Evaluation (SITE) Program is a
secondary refrigerant process.  A prototype commercial remediation plant
has been designed and built for this program, and is illustrated in the
photo of Figure 2. The capacity of the plant is a nominal 10 gpm of ice
produced from an aqueous waste stream with a freezing point of 20o F.
      The plant contains all of the components described in a typical  freeze
crystallization proce'ss above,  including the crystallizer, eutectic separator,
crystal  separator/washer, heat exchangers, heat pump (open cycle screw
compressor), decanters and strippers, and ancilliary utility related
systems.
     The plant is designed for ultimate transportability, using modular
design concepts developed by Applied Engineering Co., Orangeburg, SC, the
acknowledged  leader in this field. The plant is contained in two modules
designed for transport on the back of low-boy trailers. Each measures
approximately 50' 1 x 13' w x 11.5' h.  They are picked off upon arrival at
the site by a standard road crane, and one placed on top of the other.  The
                                  20

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            FREEZE TECHNOLOGIES CORPORATION

three electrical and thirty flanged-pip ing interconnections take about a
day to complete.
     The plant is totally self-contained except for electrical supply,
containing instrument air, cooling water, electrical distribution, and
electrical heating components.  It has a distributed digital processor that is
programmed to operate without attendance, using on-line quality sensors
to evaluate process efficiencies and discern any operating problems,
recycling effluent for re-processing  if warranted.
        S.I.T.E. DEMONSTRATION PROGRAM - STRINGFELLOW NPL

     The FTC Direct Contact Secondary Refrigerant Freeze Crystallization
Process was accepted by EPA's Office of Research & Development, SITE
Program, into the third phase of their program, when first proposed by
Freeze Technologies. A program with the State of California, Department of
Health Services, Alternative Technologies Office, was already in place, and
the selection of the Stringfellow NPL site had been agreed to with the state.
     The goals of the SITE program are, among other things, to
demonstrate applicability of a technology on as general a waste stream as
can be found, and to develop the best economic and performance criteria
that can be projected from test results. Freeze Technologies proposed that
testing could be performed with either a .5 gpm portable pilot plant or
with a 10 gpm prototype remediation plant,  designed specifically for
Superfund-type work. The groups involved in the demonstration of this
technology concurred unanimously that the larger plant is a better vehicle
for accomplishing the goals of the program.
     The current schedule will have the equipment at the Stringfellow
NPL site in late July and installed and ready to operate in early August.
The SITE tests and sampling program will occur over a two to three week
schedule in August, with a public visitors day on Sunday, August 16, 1989.
Further testing for reliability and longer-term performance confirmation
will continue into September, and the plant will be removed from the site
by the end of September, after appropriate  decontamination.
     This demonstration program is designed to have minimal impact on
the host site, a condition that is paramount  in the planning at the EPA
Regional level and with local communities.  In our case, we will fit the
freeze equipment in as a 'black box' in the pipeline that carries wastes
from the NPL site to the on-site pretreatment plant. We will intercept the
wastes between the collection wells and the pretreatment plant, process
                                  21

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              FREEZE TECHNOLOGIES CORPORATION

 the wastes, then recombine them for transfer to the pretreatment plant.
 The residence time in the freeze crystallization plant, including storage
 before and after the actual freeze processing equipment, will be 72 hours.
      Since the freeze process operates in closed vessels, with recycle of
 refrigerants and wastes at temperatures well below ambient, there are no
 emissions from the process. An option exists at Stringfellow for treating
 the concentrated effluent for metals recovery, for organic by-product
 extraction, or by solidifying the concentrate for subsequent landfilling.
 The by-product recovery is an attractive option as it eliminates a large
 volume that is now landfilled.
          WASTE TREATMENT WITH BY-PRODUCT RECLAMATION

      Remediation offers some opportunities for by-product recovery, but
 more frequently these applications occur in on-going RCRA generation
 facilities. Here we'll discuss, first, the generic conditions that favor freeze
 crystallization treatment, and how other unit processes can be used with
 freezing to offer a complete remediation or by-product recovery process
 train. Then we'll cover a few recent applications we've reviewed and
 tested using freeze crystallization.

 GENERIC APPLICATION CONSIDERATIONS -

      Freeze crystallization works by making pure crystals from water, or
 other components, in a waste solution. The waste must be in liquid form,
 so contaminated soils are treated by first washing the impurity out of the
 soil into awash solvent, usually water. In the case of aqueous based
 wastes the crystal that is produced is ice, and all impurities are excluded
 and remain in the concentrated liquid portion. The process is effective in
 removing water from these wastes, reducing the volume that must be
 dealt with.
      Since crystallization excludes all impurities from the ice, all
 impurites are equally removed - the freeze process is capable of  treating
wastes with heavy metals, all types of dissolved organics, and radioactive
materials. And  all of the impurities are reduced in concentration
 ia the effluent by a factor of about 10.000
      Freeze crystallization is not the answer for all applications, and the
chart in Figure  3 gives an indication of the conditions that favor it's use
over alternative treatment technologies.  The chart demonstrates that
                                  22

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             FREEZE TECHNOLOGIES CORPORATION

freezing becomes more economically and technically competitive as the
waste becomes more concentrated and more complex. For instance, wastes
with heavy metals require concentrations of 1,000 to 10,0000 mg/1 to be
economically recoverable with freezing.  Aqueous streams require organic
concentrations of 3  to 7 wt-% before it is more economical to treat with
freeze crystallization than by conventional means. Yet, when the waste
contains both organics and heavy metals freeze becomes more economical
than multi-process  treatment trains using conventional technologies at
between .5 and  1.5 wt-% total contaminants.

CASE STUDY 1 - Stringfellow Leachates
      Treatability studies were performed on Stringfellow leachates with
the approximate composition shown in Table 1. These tests confirm that
freezing will recover over 90% of the water, concentrating the impurities
into a minimal volume for disposal and/or recovery operations. In the
treatability tests (methods and equipment described below), crystal clear
melt was produced with a reduction in conductivity from 39  mS/cm to less
than .02, approaching a ratio of 1000:1. Table 1 also shows anticipated
effluent qualities at 90% recovery of water from the leachate.
      Currently the leachate from Stringfellow is treated in a conventional
system consisting of hydroxide precipitation of heavy metals and activated
carbon adsorption of the organics. The sludge is disposed of in a hazardous
waste landfill, and  the carbon is returned for regeneration. Treatment
costs with this scheme are outlined in Table 2. Throughput at Stringfellow
has been slowly declining, with current production from the interception
wells at about 225,000 gallons per month.  The annual cost for only the
variable items that can be displaced by treatment with an alternative
technology is about  $1.2 million.
      With freeze crystallization, the operating costs in this size plant are
about $.09 per gallon. Costs as a function of treatment plant size are
summarized in Table 4.  The variable costs using freeze crystallization for
treating the Stringfellow strong leachate would total less than $.25 million
per year. Depending on amortization rates for the equipment, the annual
charge would range  from $.2 to $.5 million. Freeze crystallization will also
leave a concentrated waste stream of about 1300 cubic yards. Incineration
of this might cost as much as $300,000 per year.

CASE STUDY 2 - Mixed Industrial Wastes
      Industrial facilities often have wastes that are collected from a
variety of places and treated at the end of the pipe.  In metal fabrication

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              FREEZE TECHNOLOGIES CORPORATION

 shops with electroplating, metal cleaning, pickling, stamping, machining,
 and other operations, the waste coming out the end of the pipe might
 resemble the analysis shown in Table 3.  A typical treatment train might
 include an oil-water separator, neutralization, hydroxide precipitation, and
 discharge to a POTW for organics removal.  However, municipalities are
 looking much harder at toxic organic discharges, and often some of the
 cleaners used in the plant are methylene chloride or other toxic chloro-
 solvents.
      Freeze Technologies has performed laboratory testing on a waste
 such as this.,collected after an API separator. Over 90% of the water was
 converted to ice. Alkalinity and sulfate salts were precipitated with heavy
 metals, hardness cations, and probably to some degree with sodium ions.
 After about 75% water removal a second organic phase began to form, and
 a significant portion of the influent organics partitioned into this phase
 that was composed of about 75% organics and 25% water. The water phase
 contained less than 10% organics, but had most of the dissolved salts.
      The organic phase that forms this way will have a high heating value
 so it can be incinerated directly, or perhaps recovered for its fuel value.
 The tests in the batch treatability lab showed that this organic layer had a
 specific gravity much less than ice,  and it collected in the top of the ice
 drain column. This will allow its recovery from a freeze crystallization
 process by making minor changes in the wash column design.
                        TREATABILITY TESTING

      Within the context of the CERCLA/SARA legislation, and the programs
and regulations that the Agency has adopted to implement it's provisions,
it seems appropriate to address treatability testing and the impact on new
technology utilization in Superfund and other remedial actions.  First, given
the complex waste matrices normally encountered in the vast majority of
remediation sites, Superfund or RCRA remedial actions, treatability studies
should always be conducted.
      Most Remediation Project Managers realize that soil treatment
technologies are sufficiently new, and the wastes so diverse, that
treatment feasibility testing is needed, especially with new technologies.
But it is amazing how many of these managers labor under the
misconception that a wastewater analysis is sufficient to define the optimal
treatment train for cleaning up liquid waste streaims. At a major tertiary
treatment sewage reuse application in the early 1970's, where the effluent
                                   24

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             FREEZE TECHNOLOGIES CORPORATION

was thoroughly characterized, the reuse client wanted to demonstrate the
treatment train and reuse application. A 2 month, $150,000
demonstration program turned into a year effort and $1 million
expenditure, and resulted in several major equipment innovations and
rather drastic modifications to the conventional treatment design criteria.
      From our experience with 8 years of development of the freeze
crystallization process, and another 10 years of development of
environmental process technology, there are a number of guidelines we
would propose for treatability testing in EPA Superfund and other .
industrial waste programs:
      1) Treatability studies should always be done by the technology
        developer, for several reasons.  First, the developer is the one who
        will give process guarantees, and this is one of the necessary steps
        in giving warranties. Second, the best knowledge of how actual
        waste characteristics impact process performance is resident in
        the developers' staff, and expansion of this database is a needed
        and beneficial part of the Agency's function in the Cleanup of
        America. And third, the expenditure for treatability studies
        means nothing if they don't result in better, more efficient, more
        economical treatment at contaminated sites, and this won't be
        done without the involvement of the developers.
      2) Treatability studies should be incorporated into the RI/FS
        activities, and replace the paper studies that are currently the
        basis for selecting between alternative treatment technologies.
        There are two reasons for getting the developers involved at this
        stage: their input into technical solutions, and more accurate cost
        information for the Agency to select between alternative
        treatment options at a given site. The REMS and ARCS contractors
        are at best 6 months behind on individual technology
        development programs, and more frequently 18 to 30 months.
        The RI/FS process is away for EPA to effectively help the
        technology transfer from the developers to their contractors.
      3) The EPA and its contractors should not attempt to define the
        treatment technologies at such sites, but rather should conduct the
        procurement activities in such away as to elicit complete
        strategies from technology developers. Most remediation sites
        have the need for a variety of treatment technologies.  The wastes
        occur in several  media, and the compositon at most sites varies
        significantly with the location and goegraphy. There is a great
        deal of networking going on between technology developers, and
                                   25

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              FREEZE TECHNOLOGIES CORPORATION

         the most efficient method for defining treatment trains is to
         define a clean-up standard and let the individual developers
         provide the train of technologies for providing that.
      The technology developer should have an institutionalized place in
 the remediation activities of Superfund and private clean-ups. The best
 process technology is resident in this community, and this resource should
 be used for its expertise in a way that ensures competition in procurement
 and full assessment of alternatives. One clear way to provide this, if not
 the only way, is to procure clean-up strategies on a competitive basis, by
 writing performance specifications based on ARAR's. Very many ROD's are
 issued with exceptions to ARAR's without a solid technical basis, which is
 the only basis allowed by statute. If all bidders of new technologies take
 exceptions to the ARAR's, then there is a technical basis which is
 defensible.
      Freeze Technologies performs treatability studies in the apparatus
 shown in the photo of Figure 4. A simplified flow diagram for the unit is
 shown in Figure 5.  The unit operates in a batch mode. Feed is drawn
 under vacuum into the crystallizer, and recirculation between there and
 the drain column is started with the slurry pump. Refrigerant is pumped
 into the crystallizer, where it bois.as it is heated by contact with the waste.
 The refrigerant vapor passes into a refrigerated condenser, condenses, and
 is pumped back to the freezer.  When the drain column is packed full of ice
 the process is stopped and the ice is washed and melted.  The concentrate
 drains out of the ice back to the crystallizer, and is saved for additional
 testing.  Since only about 50% of the water in any batch can be converted
 to ice, simulation of 90% recovery requires 4 stages of concentration.
 Twenty gallons of sample is required to allow 12 of these staged tests.
      These tests  accomplish the following:
        - interactions between refrigerant and waste are observed, such
          as foaming or emulsification, that must be chemically stopped.
        - phase equilibria are confirmed, showing the operating
          temperatures that will be required.
        - the occurance of eutectic crystallization are observed.
        - physical properties of the waste at the crystallizing conditions
          are determined.
The impact of this information is that more detailed preliminary process
designs are possible, which in turn allows more accurate cost projections.
Problems that would be seen  in the field often show up at this stage of
testing, and design adaptations made in the batch lab are the first stage in
modifying the full scale equipment for use with new applications.
                                   26

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  FREEZE TECHNOLOGIES CORPORATION
                   TABLE 1
    STRINGFELLOW LEACHATE ANALYSES

                       Concentration, mg/1
  Component              Feed	Melt

pH                         3.5      6.5
Conductivity, mS/cm        39        .02

D issolved Organic Carbon   1125      < 1.
p-CBSA                   1670      <1.
Volatile halocarbons          9.7     < .010
Volatile ketones             H.      < .010

Na                        820      .
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   FREEZE TECHNOLOGIES CORPORATION
                                    1
                     TABLE 3
 INTEGRATED MANUFACTURING END-OF-PIPE EFFLUENT
        Waste Component

      Total Dissolved Solids
      Dissolved Organics

      PH

      Alkalinity
      Sulfates
      Chlorides
      Heavy Metals
                            mg/1
Concentration

  12,500
   8,000

     10.

   5,000
   4,700
   1,500
   3,000
                       TABLED
         FREEZE CRYSTALLIZATION COST SUMMARY
     COST COMPONENT

Amortization, 5 year SLD

Labor
Electricity
Supplies, Chem, Etc
Maintenance
         TOTALS
                          COST AT PLANT SIZE, $/GAL
$ .08
.04
.008
.010
*MZ
.145
$ .05
.02
.0075
.0075
jmi
.09
$ .015
.005
.006
.005
.004
.035
                     28

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FREEZE TECHNOLOGIES CORPORATION
                             ',• ; V ' " ' I ^^ '' nuf
                        '        •     . ,y
               FIGURE  1
  FREEZE PROCESS PROCESS FLOW SCHEMATIC
                                            UJ
                 29

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FREEZE TECHNOLOGIES CORPORATION

              FIGURE 2
   10 GPM REMEDIATION PROTOTYPE PLANT
              FIGURE 1
     TECHNOLOGY COMPARISON CHART
           TYPE OF CONTAMINANT
1
N
RC
E
A
5
E
D
C
0
N
C
E
N
T
R
A
i
KM

VOLATILE HEAVY
ORGANICS ORGANICS
C/SITC HEAVY
bALlb METALS

STRIPPING
CARBON ADSORPTION

BIOLOGICAL & CHEMICAL
OXIDATION

R

ION EXCHANGE


ELECTRODIALYSIS

EVERSE OSMOSIS

EVAPORATION
FREEZE CRYSTALLIZATION
                30

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FREEZE TECHNOLOGIES CORPORATION




              FIGURE 4
  BATCH TREATABILITY TEST LABORATORY
                31

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   FREEZE TECHNOLOGIES CORPORATION
                 FIGURE
  BATCH TREATABILITY STAND PROCESS SCHEMATIC
«"•
                   32

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Purification by  froth  flotation

ir. C. Mosmans

      The purpose of this paper is to describe froth
flotation and the guiding principles in the field of
purification of contaminated soil and waste.
Purification by froth flotation.
      The mosmans method has been used for the
decontamination of soil and waste in the Netherlands
since 1983. This method is effected by well chosen
mineral seperation techniques which together result in
•a complete purification process. The most important,
but also the most complex part of the mosmans method
is the froth flotation technique.
      Mosmans Mineraaltechniek BV is an independent
organisation with a laboratory for research and
development of mineral seperation methods. The
laboratory spent several years to develop flotation
processes for the purification of polluted soils,
waste and waste effluents. It is fully equipped to
carry out tests on batches from grammes to many tons
by such processes as sampling, grinding, screening,
classification, gravity concentration, dense media
separation and several flotation methods.
      As an extension of the laboratory efforts and to
obtain real field experience and well trained
operators a small processing plant has been in
operation in the past six years. After several years
of laboratory testwork the plant started in 1983 with
the froth flotation of 10,000 tons of sandy soil.
After that about 3,000 tons of copper containing muddy
soil and 10,000 tons of earthy soil with lead.
              33

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 A relatively difficult project was clayey soil from
 gasworks with complex cyanide and pea.  For the very
 fine fraction (the slimes) special flotation
 techniques have been used.
 This year a conspicious soil cleaning operation will
 be carried out in Zwitserland. This soil is
 contaminated with pesticides,  herbicides and mercury
 during a fire in 1986.

 Principles of froth flotation.
       To achieve a separation  between the
 contaminatives and soil in a soil-water mixture,  the
 surfaces of the  particles have to be  adequately
 manipulated.  In  such a  way that the former  will be
 hydrophobic and  the latter hydrophybic.  The
 manipulation is  not related to changing the chemical
 structure of the particles,  but to modify the surfaces
 by selective adsorption.  The hydrophobic particles
 glue themselves  to air  bubbles produced in  the soil-
 water mixture.
      Flotation  processes are  determined by  surface
 phenomina.  The available  surface  depends  on  the
 grainsize.  For example  a  cubic grain  of  mesh size  of 1
 cm covers an  area of 6  crn2.  By splitting this cube the
 total area  increases.
Mesh size
10,000 Urn
1,000 (Om
100 Jim
10 |im
1 jim
0.1 (am
total ar^a
6 cm2
60 cm2
600 cm2
6,000 cm2
60,000 cm2
600,000 cm2
remarks
grains are too heavy
for flotation
normal froth
flotation
special flotation
technology
It is obvious that clay or silt has much more
area/gramme than a sandy soil.
             34

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                                       roosmans
Potential
                        A particle in water  obtains an electric surface
                  charge due to partly  ionisation,  adsorption,
                  orientation of dipoles  or  crystal lattice defects.
                  Around the charged particle  a  diffuse layer or a cloud
                  of counter ions with  an opposite  charge is formed,
                  reducing the potential  to  zero. This phenomenon is
                  called an electric double  layer.
                        Figure I presents .this classic Stern -  Grahame
                  model of the electric double layer.  In the figure the
                  S plane represents the  closest distance of approach of
                  the counter ions.
Stern layer - counter ions

                  \ayer - reduction of- potential te>
       layey
                                                 t?is6ance -^

                       When the particles are forced to move in
                 relation to the  liquid,  the slipping plane in the
                 diffuse layer shows  a  potential,  the Zeta potential.
                 This electrokinetic  phenomenon is very practical to
                 study the manipulation of the surfaces.  Two methods
                 are in use, electrophoresis and streaming potential
                 measurements. Figure 2 and 3 present these methods.
n»ic*-0sc0pa - w eaSHrement- of velocity
         of jnoaU particles in suspension
                                                                      of- water
                              35

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                                               mosmans
                                There are particular ions that are free to pass
                          the electrical double layer. These ions are called
                          potential determining ions. By a titration procedure
                          the effect of these ions can be determinded. The
                          condition which the ions compensate the surface charge
                          is called zero point of charge or iso electric point.
                          For example, for a particle CaCO3 the potential
                          determining ions are Ca, CO3 and the pH, because of
                          the equilibria with HCO3 and 003.
                          Material
                                      2PC
                         Controlled bv the concentration
                          CaCO3
                          CaF2
            pH    9,2
            pCa   3,5
            pH    2,5
H
Ca
H
Coulowibfc. repulsion
      Counter ions which adsorb only by means of
electrostatic attraction are called indifferent
electrolytes. They "compress" the diffuse layer.
Examples are A1-, Fe- and Ca-ions. These are the
anorganic flocculants in water purification.
      The third type of important ions exhibit surface
activity and electrostatic attraction. They are called
surface active counter ions. To these belong the wide
range of flotation collectors,
      The effects of an electrical double layer are-
illustrated by coagulation and a special flotation
method for very fine particles. For the coagulation of
two particles there are two forces, the coulombic
repulsion force and the London - v.d.  Waals attraction
force,  resulting in a barrier preventing coagulation.
Addition of Fe-ions compress the diffuse layer,  the
barrier diminishes,  and coagulation may occur, see
figure 4.
                   '   -"—-•-- occurs
                                      36

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                water1
•fresh water
ity of surface active, re^tvit ->
      Fine contaminatives,  say  less  than 5 \im are
generally not floatable.  But  by the  addition of coarse
"carrier", particles and  under  conditions in which the
unwanted fines adhere  to  the  carrier,  a  purification
by normal froth flotation of  the carriers is possible,
see figure 5.
      In froth flotation  adhesion is necessary between
the particles and the  air bubbles rising through the
pulp. There are three  interfaces,  particle - water,
particle - air and water  - air.
      In fact, the thermodynamics of surfaces is valid
for all the three interfaces. But for the sake of.
simplicity the particle - water interface is conform
to the electrial double layer concept.  The water - air
interface is conform to the alteration of surface
energy.
If a surface active or heteropolar reagent is added to
water the surface energy  decreases,  see  figure 6.
      This is a  result of the heteropolar nature of
the compound. These molecules adsorp preferentially at
the water-air interface.  They are arranged with the
hydrophobic  tails into the air  and the hydrophylic
heads immersed  into the water,  see figure 7.
                          Air
                          Water
                                   negatively charged
                          ®  counter ions
                         These surface active  reagents  are  called  frothers.
          A  few  examples;
                         CH3-CH-CH2-CH-CH3          013-(O-CsHg) n'-OH
                             CH3     OH                , "  ''        ?'"%.    -'•
                         methyl isobutyl  carbinol        polypropyiene^-glycol
                                       37               •.-*:..•--.•

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                                           mosfnans
          water
particle A
     weteabte"
           water
     air
 L
particle &
          water
       In the  soil-water or waste-water mixture bubble
 contact must  occur with the contaminatives. Figure 8
 presents a cross section with the surface energy as
 surface tension  (= d).

 Investigations
       The investigator has to manage many flotation
 variables. In addition he' has to cope with the
 representativity of samples and with hardly to be
 determinated contaminatives.  A consequent approach
 involves the following stages:
 -     Sampling of contaminated soil or waste.
 The samples have to be representative,  not only in
 respect to chemical but also in respect to
 mineralogical composition.  If major differences exist
 between parts of the contaminated area,  separate
 samples shall be obtained.
 Sampling methods and sampling statistics  as  used in
 the mining industry are very  useful.
 -      Determination of soil  and contaminatives.
 Chemical analysis provide only part  of  the information
 needed.  Mineralogical analysis and grain  size
 distribution  are necessary  for developing a  flotation
 process.  Techniques  of  mineralogical  analysis are x-
 ray analysis  and the  examination by  a petrographic
 microscope.
       Micro scale tests.
 Bubble pick up technique,. Hallimoand  tube and a\r
 release  tube are  employed in flotation research of
 contaminated soils. Figure 9,  10  and  11,  present these
 simple but effective  and valuable methods.
       Batch testing
To investigate the flotation variables many tests with
quantities of about half a kilogramme have to be
carried out.  Significant variables that are subject to
            38

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                                            rnosmans;
bubble pick-tip
         -flotation
        O
control are type of collector, frother,  activator and
depressor, pH, conditioning time,  flotation time, pulp
density and temperature.
In batch flotation a given mixture is fysico-
chemically prepared, aerated, whereby it becomes
separated into a froth and a residue.
      The particles diminished into the froth
   according to:

      C - Co e~St       t   = time
                        Co  = concentrations at t = 0
                        S   = constante (slope)
      Figure 12 presents this idealized equation with
data of sand, clay, water and complex cyanide.  Each
being expressed as a percentage of the initial
quantity.
The research focuses on the alteration of slopes, to
make them steeper for contaminatives and flatter for
clay, silt, sand and (water).
-     Laboratory testing may be followed by pilot
plant tests to provide continuous operating data for
design, and to ensure that laboratory tests are
reproducible on plant scale. Besides the possible
build up of bicarbonates, sulphates, calcium and
magnesium in the recirculating water should be
studied. Flotation cells are arranged subsequently.
Each cell separate only a part (the recovery) of the
contaminatives.
For example, 50% recovery in each cell results  for 4
cells in: 50% + 25% + 12,5% + 6,25% = 93.75% recovery.
-     Plant practice in soil and waste flotation.
Each separation flow sheet represents the best
solution at given conditions, such as volume of
contaminated soil or waste, the desired final grade,
da-ta from-laboratory work and" available equipment.
                                   39

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                                                     mosmans
•fig 12.
                               Note
                                     The above mentioned, mineral  processing
                               techniques have been adopted from  the mining
                               Industrie. Over the past  75  years  froth  flotation has
                               become the most important separation method in the
                               mining Industrie.  Almost  the entire world supply of
                               copper,  lead,  zinc,  nickel and many others is first
                               collected in the froth  of the flotation machine. But
                               also nonmetallics  are caught in the froth such as huge
                               tonnages of phosphates, coal, fluorite, feldspar.
                               soluble  potassium  chloride etc.
                                           40

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  Reverse Osmosis: On-Site Treatability Study

                     Of

Landfill Leachate At The PAS Site In Oswego, NY

                     by
                Charles Goulet
        Seprotech Systems Incorporated
               2378 Holly Lane
               Ottawa, Ontario
                  K1V 7P1

                     and

               Harry Whittaker
 Environmental Emergencies Technology Division
             Environment Canada
               Ottawa, Ontario
                  Kl A OH3

                     and

              Robert Evangelista
              RoyF. Weston, Inc.
  Response Engineering and Analytical Contract
        GSA Depot,  Building 209 Annex
               Edison, NJ 08837

                     and

                  Tom Kady
         Environmental Response Team
      U.S. Environmental Protection Agency
            GSA Depot, Building 18
               Edison, NJ 08837
               presented at the
      Forum on Innovative Hazardous Waste
    Technologies: Domestic and International
                in Atlanta, GA
                 19 June, 1989

                    41

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                   Reverse Osmosis: On-Site Treatability Study

                                     Of
                Landfill Leachate At The PAS Site In Oswego, NY
1.0 Introduction

The Pollution Abatement Services  (PAS) site  in  Oswego,  New  York,  was
remediated in the mid-1980's when drums of toxic wastes were removed from the
site,  and the contaminated soil was contained' by means of traditional methods: a
slurry wall along its perimeter, a leachate collection system,  and a clay and high
density polyethylene cap.  The  continuous monitoring and maintenance  of this
Superfund site has consisted of the collection and off-site treatment of approximately
65,000 gallons of leachate monthly.  The leachate management methods has cost
government agencies money,  manpower and time. To reduce these expenditures,
Region H of the United States Environmental Protection Agency (US EPA) requested
the engineering assistance of  the US EPA Environmental Response Team (ERT) to
explore the feasibility of on-site treatment technologies.

In  agreement with  the 1986 Superfund Amendments Reauthorization  Act (SARA),
alternative  and  innovative  technologies  were  preferentially  addressed.
Environmental engineers from the US EPA,   Environment Canada,   and the
Response Engineering  and  Analytical Contractor (REAC)  analyzed  previous
successful bench-scale work and selected reverse  osmosis (RO) and enhanced
ultraviolet oxidation, also called UV photolysis/ozonation/hydr6gen peroxide, for
a field pilot-scale study.

This paper concerns the application of reverse osmosis for on-site treatment  of
hazardous wastes. It reviews the basic principles that govern the process and reports
on the treatability study that was conducted at the PAS site in the summer of 1988.
Since four different  brands of RO membranes were investigated,  the evaluation of
their^ performance focuses on the quality of their respective permeate.  The purpose
of this paper is to provide the preliminary results of this study.
                                    42

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2.0  Reverse Osmosis: The Treatment Technology
2.1 Process Description

Reverse osmosis (RO) is a membrane technology which  can serve a dual-purpose in
hazardous waste treatment.  It is a means to reduce wastewater volumes, and in the
process,  the membrane generally retains most of the contamination within one of
the two effluents,  namely the concentrate.  The permeate .stream is  aimed to be
discharged in the environment,  whereas the concentrate requires further treatment.

RO is accomplished by pumping an aqueous dilute solution at a high pressure over a
semi-permeable membrane.  As the solution  sweeps the surface of the membrane,
the solvent,  water,  is preferentially attracted.  Its transport across the polymeric
layer is driven by the difference between the osmotic pressure of the solution at that
location on the membrane and the hydrostatic pressure of the solution.

The chemical substances present in a given feed solution differ  in their affinity for
the  membrane material.   The interaction between the  membrane,   the solute
components,   and the solvent governs the performance  of  any such  system.
Different schools of thought have explained the mechanism by which solutes are
transported across  the membrane. The most prevalent theories are : the preferential
sorption-capillary  flow mechanism (Sourirajan and  Matsuura,  1985) and  the
solution-diffusion transport mechanism (Lonsdale et al.  1965).

Once the initial separation has been performed,  the solution retained at  the,
membrane surface  is subjected to further separation as it flows along the polymeric
surface. Thus, there is not only a step-wise change in solute concentration between
the two sides of the membrane but also a gradual increase from the feed influent end
to the concentrate effluent end on the same side of the membrane.
 2.2 Applications

 Reverse osmosis has been used extensively for the past twenty-five years to remove
 inorganic compounds for the production of potable water from brackish water and
 seawater.  Economic and environmental considerations have promoted its use for
 concentrating electroplating rinse waters since the  '70s,   and its use has been
 explored for other  hazardous waste treatment since  then.  Beginning in 1984,
 Environment Canada  has  been demonstrating  reverse osmosis in the field for
 treating  dilute  organic solutions such as landfill leachate,  industrial wastewater,
 and contaminated aqueous solutions generated by chemical  spills. Some of the
 solutions successfully investigated in Canada include:
                                   43

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             0 spilled  wood  protection  solutions  containing  tetra  and
              pentachlorophenols (PCPs);
             0 leachate contaminated by volatile organic compounds;
             0 leachate contaminated by polychlorinated biphenyls (PCBs);
             0 potato wash water;
             0 fish blood water;
             0 pesticide container wash water;
             0 industrial wastewaters containing monoethylene glycol;
             0 surface runoff contaminated by benzene,  toluene,  and xylenes (BTX);
             0 solvent contaminated wastewater from  an aircraft maintenance
              facility.


 2.3  Pollutant Concentration Considerations

 The influent pollutant  concentration for which a  reverse  osmosis system will
 economically produce a permeate of sufficient quality for discharge in a sewer system
 or mto surface waters varies from one chemical compound to another,  and from
 one application to another.  For example,  a treatability study of an industrial waste
 effluent revealed that a reverse osmosis membrane would not withstand long-term
 exposure to a.1% phenol solution. However, selection of another membrane and a
 change in the chemical nature of the phenol allows the RO system  to increase the
 phenol concentration up to 8% without either affecting the physico-chemical or the
 structural integrity of the RO membrane.  As the permeate from the first stage is,  at
 1500 ppm phenol concentration, still too highly contaminated, a second stage has
 been added and the permeate meets the effluent discharge criteria set by the
 concerned jurisdiction.  The  phenol recovered, by  the  two-stage  RO system  is
 expected to pay for the pollution control system within twelve  months.

 In this section, a review will be made  of the two characteristics that play the most
 significant roles in defining the ranges of pollutant concentrations in  which RO will
 be effective. These are the osmostic pressure and the chemical compatibility between
 the pollutants and the membrane materials.


 23.1 Osmotic Pressure

 Osmosis is a  natural phenomenon.  The  term defines the  diffusion of a solvent
 through a semi-permeable membrane which separates two  solutions having
 different molar concentrations of solute.  The semi-permeability of the membrane
 refers  to  this property to allow  the  solvent through but not the solute.  An
 equilibrium is reached when the solvent flow stops.  At this point,  the hydrostatic
pressure difference between the two liquid columns represents  the osmotic pressure
difference between the two solutions. To generate a net water transport through the
membrane, the osmotic pressure difference must be overcome  (Figure 1).
                                  44

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The osmotic pressure of an aqueous solution is caused by the presence of chemical
species other than water.  The type of compound and its concentration, the pH, and
the temperature of the solution have an influence on the osmotic pressure,  and
thus,  on the driving pressure necessary to induce reverse osmosis. The wastewater
should  exert  an osmotic  pressure  no greater than the membrane's  operating
pressure limit  to allow for water permeation.


2.3.2 Compatibility With Membrane Materials

The choice of  a membrane is governed to a great extent by its chemical  resistance.
The membrane surface material, the backing polymer,  the adhesive agents,  the
seals,  and all related hardware must sustain the chemical abuse to which the
pollutants  might subject them.  Reverse osmosis systems are mostly sensitive to
long-term exposure to oxidants, and to low molecular weight halogenated organic
solvents.  Also,  field experience reveals  that some RO membranes tend to swell
from long-term contact with BTX.

Membrane research and  development continuously evolves as a result of customer
demands,  the introduction of new  synthetic materials,  and  the quest for better
performing membranes.  Chemical resistance is constantly increased, in particular
that to free chlorine, and the allowable feed pH range has been widened.

Finally,  compatibility includes the notion that any pollutant will be rejected.  It is
undesirable that a membrane preferentially allows the permeation of contaminants.
 2.4 Performance

 In hazardous waste treatment, the ideal reverse osmosis membrane is one which:
 retains all pollutants;  possesses  a very high water permeation rate;  chemically
 resists  virtually all compounds;   and needs very little maintenance (washing or
 replacement). However, RO membranes do not separate 100% of the contaminants
 and cannot  recover 100% of the water from the  contaminated solution.  Thus,
 performance assessment of RO membranes is primarily based on  the qualitative
 (percent rejection) and quantitative (water permeation) aspects of the separation.
 2.4.1 Qualitative Aspects

 Qualitative membrane performance is assessed by measuring the concentration of
 given solutes in the feed solution and in the permeate stream. From this data, the
 percent rejection is calculated by means of the following formula:


                      R, =  (l  -  Cip/Cif)-x'100%

                                      45

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     where:  Rj   -is the rejection of solute "i" expressed as a percentage;
             Cip  represents the concentration of solute "i" in the permeate;
             Cjj  represents the concentration of solute "i" in the feed solution.

Rejection is considered from the perspective that a given solute is prevented from
entering the permeate stream by the semipermeable membrane.  In this sense,  one
should not confuse it with the removal of a given solute from the permeate.

Typically,  a membrane retained for its rejection capability will cause a change in the
pollutant concentration by one order of magnitude or more (in other words,  a 90%
rejection or more).  As a result, the concentration of each pollutant in  the  feed
greatly affects the number of stages needed to meet the effluent discharge criteria for
the permeate.
2.4.2 Quantitative Aspects

RO systems are amenable to modular design.  This characteristic allows for the
manufacturing of systems to serve specific purposes,  and yet,  the productivity of
each system  can be increased by adding membrane modules,  or replacing
membranes within each module by better,  and newly developed membranes, or by
plumbing a second system to the first one.

All designs  are based on the permeation rate of membranes.  As each  aqueous
solution interacts differently with a given membrane,  a systematic approach to
determine the best membrane for  each  application must address the following
aspects:  the osmotic pressure expected and the necessity of special cleaning methods.
In addition,  the chemical compatibility of all materials should be examined.

Water  recovery  ratio  is another  quantitative  criterion  which is  particularly
important for wastewater volume reduction applications. It is defined as the portion
of the  feed  solution  which is recovered  as permeate,   and  it  conveniently
corresponds to the volume reduction achieved,  the ratio of the permeate  flowrate
to the sum of the concentrate and the permeate flowrates represents this quantity:

                     A    =    Qp  /  (Qp  +QC)


     where:  A   is the water recovery ratio (expressed in percent or as a fraction);
             Qp  is the permeate flowrate;
             QC  is the concentrate flowrate (units consistent to those used for Q ).
                                   46

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Water recovery is limited by the rise in osmotic pressure that accompanies a volume
reduction,  and the precipitation of salts at the surface of the membrane.  Therefore,
a compromise must be reached between how much permeate should be recovered
and the membrane maintenance needed to keep the membrane permeating.
2.4.3 Mass Rejection Rate

The mass rejection rate is a practical means to compare membranes.  Its concept
embraces the needs for high permeation rates, and for high contaminant rejections.
Its  calculation  is  performed by  multiplying  the  permeate flowrate by the
concentration difference existing between the feedwater and the permeate  for a
given contaminant.  It represents  the  mass of a  given contaminant which  is
prevented from entering the permeate or reciprocally  that which is retained within
the concentrate.  A mass balance performed around a membrane system yields:
where:
                      m, =  (cif-qp).Qp  =
                 nij  is the mass rejection rate of solute "i";
                 Cic  is the concentration of solute "i" in the concentrate;
                 all other quantities, Cif/ Cj_ Q , and Qc were defined above.
2.5 Limitations To Reverse Osmosis
                                t»
The following aspects may cause interferences to the RO membrane's performance:
the feedwater source,  the chemical compatibility of the membrane with respect to
the feedwater composition,  the solution osmotic pressure,  fouling  factors and
scaling  agents.  Silt or colloids can become entrapped and significantly reduce
productivity and rejection.  The fouling potential is especially high for levels of iron
higher than 0.1 ppm as the divalent form (Fe"1"*") will likely form colloidal iron (Fe+++)
in the presence of oxygen. Those salts which are most susceptible to precipitate as a
scale on the membrane surface are calcium  carbonate (limestone),  calcium sulfate
(gypsum), and silica. Hence,  pretreatment  should be addressed carefully as it will
impact on the longevity of the RO membranes.

Various  protective,  monitoring and control components must be integrated  to
allow for the safe and reliable field operation of any reverse osmosis system.  On the
upstream end of the membranes, also called  the feed end, filters act as a preventive
measure by removing suspended solids down to the micronic size range. Generally
it is recommended that particles having a size greater  than one fifth of  the smallest
dimension of the feed conveying channel be removed.  As  a rule of thumb,  5 um
filters represents a suitable size for reverse osmosis (Lombard,  1986).   In addition,
pressure and temperature gauges and switches are normally incorporated.  These
ensure  that  the  membranes  will  be  used  under  normal operating conditions.

                                     47

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Currently, automation has yet to be developed to allow for feedback regulation of
key operation parameters such as pressure, temperature, recirculation rate, and
conductivity in the permeate.
3.0 Methodology
3.1 Leachate Characterization

Leachate characterization was carried out in December 1987. Samples collected at the
PAS site in Oswego, NY ,  were analyzed by REAC.  The analyses focused on:  the
total priority pollutants; total and suspended  solids;  titration curves;  pH;  TOC;
BOD; COD;  and flashpoint. The TOC level was 870 mg/1. Furthermore,  the volatile
organic compounds with the highest concentrations were:  methylene chloride
(25900 ug/1);  trans-l,2-dichloroethene (13300 ug/1);  xylenes (10000 ug/1 total);
toluene (6300 ug/1);  and ethylbenzene (4100 ug/1). Also,  analyses showed phenol
(935 ug/1) and 2,4-dimethylphenol (435 ug/1) as  the primary base/neutral/acid
extractable  compounds.  No organochlorinated pesticide,   nor polychlorinated
biphenyl (PCB) was detected. Among all investigated metals,  nickel (2150  ug/1),
arsenic (35.3 ug/1), chromium (22.8 ug/1), and cadmium (16.0 ug/1) displayed the
highest concentrations.


3.2 Bench Scale Treatability Study

As a result of the leachate  characterization,   phase I  engineering studies were
undertaken.  Another  sampling  effort was performed  at  the PAS  site  on
23 February, 1988. It involved the complete filling of two 55-gallon lined drums (to
eliminate headspace)  and  overpacking in  85-gallon  drums.   Subsequently,
bench-scale  testing was conducted  at the River Road Environmental Technology
Centre in Ottawa,  Ontario,  CANADA.  Two  leachate treatment schemes were
investigated from' 24 to 27 February, 1988. They were: powdered activated carbon
adsorption followed by microfiltration (PAC-MF) and reverse osmosis; and two-pass
reverse osmosis.

In both treatment tests,  the landfill leachate was mildly acidified by hydrochloric
acid addition to pH 6. As the rate of oxidation by oxygen is  inversely proportional to
the hydronium ion concentration, lowering the pH is meant to preserve iron as a
ferrous salt  solution,  thereby preventing colloidal fouling of the membrane.  The
use of 5 um filters provided additional protection against debris and  particulate
dogging. Analyses for the bench-scale studies covered:  total priority pollutants plus
40 other pollutants except PCBs and pesticides;  iron, calcium, and priority pollutant
metals, sulfate; cyanide; total suspended and dissolved solids;  TOC;  and COD.
                                    48

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The rejection percentages  of first pass  RO alone,  without PAC-MF,  were
respectively:  60.0% for methylene chloride;  78.4% for trans-l,2-dichloroethene;
above 99.9% for xylenes (total);  98.9% for toluene;  above 99.9% for ethyl benzene;
and above 99.9% for benzene.  For the semi-volatile organics phenol was rejected at
79.8% whereas higher results were exhibited for 2,4-dimethylphenol at 96.8%.  In the
case of inorganics,  nickel (98.1%),  arsenic (above 99.9%),  lead (above 99.9%), and
chromium (above 99.9%) were easily removed by reverse osmosis.  TOC level  was
reduced by  88.8%.  Second pass permeate did not significantly increase rejections
over the first pass permeate levels.

The success achieved in this evaluation  demonstrated reverse  osmosis  to be a
technically feasible treatment for the PAS site. Also,  potential savings identified in
a subsequent economic analysis  substantiated the need to proceed  with the phase II
engineering studies (Evangelista,  1988).  On the other hand,  powdered activated
carbon  adsorption followed by microfiltration separation appeared to  be an
unnecessary treatment step  because of  the economics  and the generation of
additional solid wastes.
3.3 Reverse Osmosis System Configuration For The On-Site Tests

The raw leachate was pretreated to lower the concentrations of the ferrous ion,  and
calcium carbonate,  and solubilize residual metallic species.  The following describes
the pretreatment system.  Batches of raw leachate were pumped from the recovery
wells and piped to a concrete in-ground storage tank with a capacity of 200,000 litres.
A stainless steel submersible pump fed raw leachate to the pretreatment system. The
RO pretreatment steps included:   basification;   clarification;  dead-end filtration;
acidification and dead-end filtration.   Basification   included the injection of a
25% sodium hydroxide aqueous solution into the raw leachate stream within an
on-line static mixer.  Then,  the basified leachate discharged into an 800-litre reaction
tank. The flocculating solution was transferred to a Lamella® clarifier.  The clarified
effluent was then pumped through  5-micron and 0.2-micron cartridge  filters in
series,  acidified  by  means of a 50% hydrochloric acid on-line injection,  statically
mixed, and finally discharged into a 2000-litre feed tank (Figure 2). Flows and pH
were monitored and adjusted as to maintain a pH of 10 in the reaction tank,  and a
pH of 5 in  the  RO feed tank.  The acidified leachate was then filtered through a
0.2-micron cartridge filter and introduced to  two high pressure   pumps  before
contacting the RO membranes for separation.

Environment Canada's mobile RO system was used for the phase II engineering
studies.   Its  configuration was  arranged to two  pairs  of 4"x40" spiral-wound
membranes in series in each bank.  Four different manufacturers' membranes were
utilized in the course of this evaluation;  therefore, each pair of RO membranes was
representative of one brand.
 Lamella® is a registered trademark of Axel Johnson Engineering AB, SWEDEN
                                      49

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Tests were carried out over a period of 10 days in August, and September 1988. The
distinction between each trial was established by a variation in the water recovery
ratio,  and in the operating pressure.  Sufficient time was allowed between each
sampling effort for the membranes' acclimatization.

Membrane separation generated concentrate and permeate effluents. The permeate
could, at any point in time, be discretized into four separate  streams for sampling
purposes, each one being the product of one membrane type.  The effluents were
either directed to the enhanced ultraviolet oxidation system for further treatment or
returned to an injection well in the landfill.
3.4 Sampling And Analysis Of Samples

Samples were taken at appropriate times during the trials from the RO feed solution,
also called basified/acidified leachate, from each of the four permeate ports, and
from the concentrate.  The Lamella®  clarifier sludge,  and the raw leachate were
each sampled on one occasion. REAC  Standard Operating Procedures (SOPs) #2001
to 2005 were observed for sampling,  sample  storage,  and sample shipment.  All
abovementioned  SOPs are approved by the  ERT (Evangelista,  1989).  On-site
analyses  were performed for volatile  organic compounds (VOCs) as per US EPA
methods  601 and 602 using a Hewlett Packard (HP) 7675A purge and  trap unit
followed by a HP  5830 gas chromatograph (GC) with a flame ionization detector.

VOC analyses were verified  off-site for some samples by a modified version of
US EPA method 524.2 using a HP 5995C gas chromatograph/mass spectrophotometer
(GC/MS) equipped with a Tekmar LSC 2000 purge and trap concentrator. The use of
a reduced sample size,  that  is 5 ml,  corresponded to the only adaptation to the
analytical method of US EPA method 524.2 (Evangelista, 1989).

Off-site analyses were performed for the semi-volatile organics,  also known  as base
neutral/acid extractables (BNAs), and priority pollutant metals.  BNA analyses were
done in conformity  with the separator extraction technique of US EPA method 625
by means of a HP 5995C GC/MS. Finally, priority pollutant metals were analyzed
according to the US EPA method 7000 series.   Zinc and nickel  were  quantified by
flame atomic absorption spectrophotometry using a Varian SpectrAA-300.   In the
case of arsenic and lead, graphite furnace atomic absorption spectrophotometry was
performed using either a Varian 400-Z or a Varian SpectrAA-20  both set up  with a
GTA-95 graphite furnace unit (Evangelista, 1989).
                                   50

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4.0 Results and Discussion

For each test>  the percent rejection of each membrane was computed for each
pollutant. Then,  the mean rejection was computed from  the results of all tests.
Table 1 lists those latter values for each of the four membranes labelled A to D.  The
selected  pollutants were chosen because  they  represent various  families  of
contaminants and because of  their relative  occurrence in the PAS site leachate.
Therefore,  the results tabled herein represent only a portion of those generated
during the phase II engineering studies at the PAS site.  However,  the selection of
representative pollutants is meant to provide  a broad coverage of the quantification
process. All the data can be found elsewhere (Evangelista,  1989).

In general, the RO membranes tested in this study rejected the heavy metals with
the highest success.   Among  the  organic  compounds,   the  base/neutral/acid
extractable compounds were more easily rejected than the VOCs.  Membrane A
rejected volatile organic compounds and semi-volatile organics at levels that did not
reach 85% in most cases.  The only exception was  2-methylnaphtalene  (85.0%). A
contaminant reduction of that order of magnitude was accomplished for all metals
except for lead  (10.3%) and zinc (45.4%).  Membrane B tended to retain organic
compounds  at  a  higher percentage  than  membrane  A.  Among  the  VOCs,
bromoform    (91.5%),       1,1,1-trichloroethane    (85.2%),       and
methyl isobutyl ketone (85.4%) were retained in the concentrate with the greatest
rejection efficiency. The results for membrane B  also revealed with more clarity
than those for membrane A a trend of higher rejection levels with higher molecular
weight. Benzoic acid (85.5%) and 1,2-dichlorobenzene (91.7%) were the BNAs which
were separated with the greatest ease by  membrane B.  Rejections for metals
exceeded  the 85% level except for lead (16.9%) and zinc (33.6%).  For membrane C,
separation levels rarely exceeded 80%.  The compounds that were separated above
that percentage were:  meta- and para-xylene (coeluted 84.6%); ortho-xylene (83.4%);
1,1,1-trichloroethane (85.7%); and copper (84.4%). Membrane D demonstrated its
capacity to remove in excess of 90% of the contamination  associated  to six VOCs.
These were:   1,1,1-trichloroethane  (93.3%);   bromodichloromethane (91.6%);
bromoform (99.5%); ethylbenzene (94.9%);  meta- and para-xylene (co-eluted 96.3%);
and ortho-xylene (96.7%).  Five compounds among the BNAs were  separated at
levels above 85%:   1,2 dichlorobenzene (87.9%);   4-methylphenol (89.8%);
2,4-dimethylphenol (88.5%);  naphtalene (88.9%);  2-methylnaphtalene (92.6%).  As
for all membranes, removal of metals reached one order of magnitude except for
lead (29.1%),  and zinc (53.3%).

Overall,  membrane D exhibited the best performance with the highest rejection
levels for the majority of the contaminants.  Of all membranes,  membrane D
achieved an order of magnitude  change in  the greatest number  of  pollutant
concentrations.
                                     51

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The results  indicate that the molecular size and polarity have an impact on  the
performance of RO membranes.  The RO membrane rejects the larger molecules
because  the membrane acts as a molecular sieve.   On  the other hand,   polar
molecules are less amenable to  separation than non-polar molecules. For example,
benzene  and toluene showed higher levels of rejection than the polar compounds
phenol and  4-methylphenol.  It is believed that the phenolics,  when dissociated,
can form a hydrogen bond with the membrane and diffuse through it more readily
than a non-dissociated molecule.

To  complete our  analysis of the performance from a quantitative standpoint,  the
permeation  rate of the single-stage RO system was examined for all twelve tests.
Between  0 and 21.3  hours,  six  different tests were performed on separate days of
operation where most of the fluctuations in the permeate flowrates are related to the
start-up conditions,  and the adjustment of the operating pressure (Figure 3).  At
10.3 hours,  the "spike" illustrates the effect of pressurizing the system from 600 psi
to 800 psi. On the other hand, the increase in the combined permeate flowrate (12.5
to 27.0 litres per minute) that appears at 12.5 hours results from the use of a more
dilute solution,   namely the  enhanced ultraviolet oxidation effluent.   In  the
following tests, normal pretreatment of the leachate was resumed.  The increase in
the  osmotic  pressure that accompanied the change in the feed solution at 15.2 hours
and a reduction  of the operating pressure to 600 psi caused a decrease   in  the
permeation rate from 28 to 22 1pm.  This test ended at 19.5 hours.  As the solutions
left in the tanks lost during the following 20 hours of downtime part of their organic
contamination through volatilization,  the permeate rates  reflected these losses at
start-up.  A  pressure of 600 psi was maintained and flows gradually decreased to 10
litres per minute.  This trial ended at 21.3 hours.

In the next  sequence of tests,  the variation in  the  permeate fluxes  was mostly
accounted by the  adjustment of the water recovery ratio and the fluctuation in  the
chemical composition of the PAS site leachate.  After 21.3 accumulated hours of
operating time, tests were initiated at 800 psi, and the system was not shutdown
until 63.8 hours.   Varying  the recovery ratio at a  given pressure affected  the
permeation rate.   When more water was recovered, the osmotic pressure increased
at the membrane  surface,  therefore decreasing the permeation flux. On the other
hand, different osmotic pressures of the feed were associated to different chemical
compositions of  the landfill leachate.  At a fixed operating pressure and water
recovery  ratio,  the  changes  in  the osmotic pressure translated into a  variable  net
driving pressure,  and caused the instability in the permeate flowrates.    The
concentration ranges listed in Table 1 illustrate  that for some chemical species,  the
concentration varied by as much as three orders of magnitude.
                                   52

-------
5.0  Conclusion

Rejection of metals is generally easily accomplished. Caution should be exercized
when  semi-volatile  and  volatile organic  compounds  are involved  since  the
rejection efficiency is somewhat  lower than for inorganic species.  Still, acceptable
levels  of rejection can  be achieved on some  volatile organic compounds.   For
instance, membrane D rejected  several volatile compounds at levels exceeding 90%.
Therefore,  membrane selection  is an important  step of any treatability study which
is to involve reverse osmosis as  a hazardous treatment process.

The preliminary  results of the phase II engineering, studies at the  PAS site in
Oswego, NY,  demonstrated that reverse osmosis can be used as an effective part in a
treatment process for landfill leachate.  The economics  of this separation process
depends to a great extent on the liquid wastes themselves. The pretreatment of the
feed water,  the  treatment/disposal of both the RO concentrate and the clarifier
sludge bear heavily on  the economics of the process. Discharge limits ultimately
govern the costs and  the benefits  associated with this  technology.   The low
rejections of volatile organics suggest that other treatment methods be coupled to a
reverse osmosis system.  Thus, RO should not be regarded as a panacea but as means
to resolve specific contamination problems  within the context of a treatment train
where it can conveniently complement additional treatment processes.

6.0  References

Evangelista,  R.  1989.  Pilot-Scale Engineering Study at the Pollution Abatement
Services Site, Oswego,  NY. Draft Report prepared for US EPA under EPA contract
No. 68-03-3482, Edison,  New Jersey.

Evangelista,  R.  1988.   Preliminary Economic Analysis for the Proposed Treatment
Systems at the Pollution Treatment  Systems at the Pollution  Abatement Services
Site, Oswego, NY. Memorandum to US EPA ERT,  Edison, New Jersey.

Lombard,  G.  1986.  Precedes de separation par membranes.  Document de cours.
Ecole Polytechnique de Montreal, pp. 44-45.

Lonsdale,H.K., Merten,  U.,  and Riley, R.L.  1965.  Transport Properties of Cellulose
Acetate Osmotic Membranes. J. Appl. Poly. Sci.,  9:1341.

Sourirajan, S.,  and Matsuura,  T.  1985.  Reverse Osmosis/Ultrafiltration Process
Principles.  National Research Council Canada, Ottawa, pp. 1-77.

Whittaker, H., et al.  1989.  Preliminary Results of Reverse Osmosis and Ultraviolet
Photolysis/Ozonation Testing at the PAS Site - Oswego, NY,  In Proceedings of the
Technical Seminar on Chemical Spills.  Calgary,  Alberta.  Environment Canada.
June 5-6.
                                     53

-------
Concentrated
 Solution   "^
                                                                      Dilute
                                                                      Solution


, 	 ^-

	



JU
T



t ^



Dilute
^x
Solution

»
"*"

	 >




si
1
/


J

                     Osmosis
                       Reverse Osmosis
Figure 1  - Osmosis: water transport through the semi-permeable membrane
            is from the dilute solution to the concentrated solution.  At
            equilibrium,  water flow stops, and the chemical potential is equal
            on both sides. The head difference is the osmotic pressure.
            Reverse osmosis:  a pressure  exceeding the osmotic pressure
            forces the water transport across the semi-permeable membrane.
            Solutes are for the most part retained on the side of the membrane
            where the pressure is applied.
      In-ground storage
           tank
          200,0001
     Static mixer
Reaction tank
 Cap. 8001
                   02. micron
                    cartridge
                     filters
  5 micron
cartridge filters
          RO feed-tank
           Cap. 2,0001
                                                             RO system
                                         0.2 micron
                                         cartridge
                                           filters
Figure 2  -  Pretreatment System Utilized  for  the Phase  II  Engineering
            Studies at the PAS  Site in Oswego, NY.
                                    54

-------
en
en
           fl
            -

            «J

            01
           PU
Permeate Flowrate [1/min]


Recovery Ratio
                                                                                              1.00
                                                                                             -0.75
                                  
-------
                                                  Table 1  -  Summary of the Results
                                  for the Phase II  Engineering Studies at the PAS Site,  Oswego,  NY.
    Compound/Metal
                                                                 Average Percent Rejection For All Tests
                                 Concentration
                                    Range
                                  (in the feed)    Membrane A    Membrane B    Membrane C    Membrane D
                                     (Mg/1]
or
01
 Dichloromethane
 Acetone
 1,1-Dichloroethane
 1,2-Dichloroethane
 trans-1,2- Dichloroethene
 Benzene
 Bromoform
 Toluene
 Ethyibenzene
 o-Xylene
 Phenol
 4-Methyl phenol
 Benzoic Acid
 Arsenic
 Lead
Nickel
129
4912
178
635
319
60
226
75
1266
3339
121
67
46
23
4
1070
-99642
- 68768
-3612
- 6931
- 62577
- 2561
- 198966
- 26145
- 19211
- 52033
-7155
-4811
- 42331
-67
-59
- 2630
34.3
46.0
57.2
41.0
11.7
56.7
74.9
57.7
66.1
71.9
54.5
78.6
67.9
96.1
10.3
>99.9
51.5
49.5
64.7
52.3
37.3
58.0
91.5
68.4
74.3
83.2
55.7
57.4
85.5
85.5
16.9
93.8
42.5
31.6
64.3
53.7
37.0
55.8
69.1
53.3
74.6
83.4
37.8
59.8
51.7
46.1
20.0
53.6
50.5
73.8
88.2
75.3
47.4
83.9
99.5
83.7
94.9
96.6
72.2
89.8
83.3
98.6
29.1
88.2
                                                                               Printed in Canada

-------
                          KINETIC
                                    in theory and practice
ABSTRACT

During the last four years, Geokinetics has been developing a method to
remove heavy metals and other contaminants  from soil  and groundwater.
The method  is based on the electrokinetical phenomena electro-osmosis,
electrophoresis  and  electrolysis,  which  occur  when   the  soil  is
electrically charged by means of one or several electrode-arrays.

The most  important applications of these phenomena with respect to the
soil have been the dewatering of  clays by  electro-osmosis and experi-
ments to desalinize arable lands (USA, 1958 and USSR, 1966-1975).
Experiments on a very small scale to remove heavy metals from soils are
documented from UK (1980, 1981 and 1982). Though  starting promisingly,
the  authors  reported  problems  around the electrodes (precipitates),
which influenced the process negatively.

Geokinetics has  found a  solution to  these problems  by developing an
electrokinetical installation, which monitors and controls the chemical
reaction  environment  around  the  electrodes.  The  core  of  such an
installation consists  of the electrode-series and their housing, which
can be  installed in principle  at  any  depth,  either  horizontally or
vertically. The  housings are interconnected and form two separate  (one
for the cathode, one  for the  anode) circulation  systems, filled with
different chemical  solutions. In  these solutions the contaminants are
captured and brought to a container-based water purification facility.
The energy  is  supplied by a generating set or taken  from the main.

Electro-Reclamation can be applied both in situ  (soils) and on-  or off
site  (excavated  soil, scooped   out river  slush). The electrokinetical
phenomena can  also be  used  to  fence  off  hazardous  waste  sites or
potentially hazardous industrial sites.

The   technique has  been  tested  on the basis of  numerous  laboratory
experiments, using  different types   of soil   (clay, peat, argillaceous
 sand)  and  contaminants  (As,  Cd,.Co,  Cr, Cu,  Hg,  Ni, Mn, Mo,  Pb, Sb,
 Zn).  Besides,  two  in  situ  fieldexperiments   (Cu,  Pb  and Zn)   have  been
 finished and   one  "official"  in situ remediation project  (As) has  been
 succesfully terminated.

 Reduction of  individual  heavy metal concentrations can be more than
 90 %,  depending on the  energy supply  and  time duration.

 Remediation costs  are therefore  directly  related to  these   two factors.
 Costs range  from less  than US  $ 50 per  ton,  when relatively low energy
 is supplied over  long periods  (several months),  to more  than  US $  400,
 when the time period is reduced to several  weeks and the enrergy supply
 has to be increased accordingly. There  is,   however,  a   limit   to the
 current strenght   which can be used.  In practice therefore an optimum
 is calculated for  energy supply and time  duration.
 drs. R.  Lageman
 Geokinetics
                                 57

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            KINETICS
   Forum on Innovative Hazardous Waste
          Treatment Technologies
           Atlanta, Georgia USA

             19 - 21 June 1989



Theory and Practice of Electrc—P

 drs. Reinout Lageman
 Geokinetics
 Rotterdam, Groningen
 the Netherlands
                                    co-authors :
                                    drs. W.Pool
                                    drs. G.A.Seffinga
                                    Geokinetics
                 58

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                          KINETICS
                Electro-Reclamation in theory and -practice
Electroklnetical phenomena

During the  last 4  years Geokinetics  has been  developing a method to
remove heavy metals and other contaminants  from soil  and groundwater.
The method  is based on electrokinetical phenomena, which in one way or
another have been made use of since the end of the last  century. These
phenomena occur  when the soil is electrically charged with DC by means
of one or several electrode arrays :

1. Electro-osmosis : Movement of soil moisture or groundwater from the
                     anode to the kathode.
2. Electrophoresis : Movement of soil particles within the soil
                     moisture or groundwater.
3. Electrolysis    : Movement of ions and ioncomplexes within the soil
                     moisture or groundwater.

Electro-osmosis

the electro-osmotic transport depends on the following factors :

- the mobility of the ions and charged particles within the soil
  moisture or groundwater;
- the hydratation of the ions and the charged particles;
- the charge and direction of the ions and charged particles, which
  cause a net water movement;
- the ion-concentration;
- the viscosity of the pore solution, depending a.o. on the capillary
  size;
- the dielectrical constant, depending a.o. on the amount of organic
  and anorganic particles in the pore solution;
- the temperature.

From  existing  literature  and  own  experiments  the average electro-
osmotic mobility has been calculated  to  be  in  the  order  of 5.10"*
m2/U.s, where U = potential drop (V/m).

To  drain  1  m3  of  soil by electro-osmosis, the following parameters
should be known :

- the porosity;
- the moisture content of the soil to be treated;
- the conductivity of the pore solution;

Apart from these other factors like the desired time period, the use of
the  soil  after  treatment  and  safety  requirements  regards maximum
voltage and current are also of importance.

Electrophores i s

Electrophoresis (kataphoresis) is the process of  movement of particles
under the influence of an electrical field. With particles is meant all
electrically charged particles like  colloids, clay  particles floating
in the pore solution, organic particles, droplets etc.
                                59

-------
                            K I N
 The mobility  of  these  particles corresponds with that of ions. Within
 the pore solution these particles transfer  the electrical  charges and
 affect  the  electrical  conductivity  and the electro-osmotic current.
 Clay minerals as  such have  2  electrical  polarity  possibilities. One
 consists  of  the stucture-based  dipole  moment, which depends on the
 atomic masses and has an orientation  parallel to  the longest  axis of
 the clay  particle. The  second polarity  stands at right angles to the
 first and is caused by the external electrical field. It depends on the
 way of  polarization of  the electrical  double layer.  The mobility of
 clay particles is an  interplay  between  these  two  moments  and is,
 therfore, less than the electro-osmotic mobility. It varies between
 1.10-10 and 3.10" mVU.s.

 Electrolysis

 Analogous to  electro-osmosis and  electrophoresis,  where one considers
 only water transport or particle transport  respectively, with electro-
 lysis  only  the  movement  of  ions  and  ioncomplexes  is  taken into
 consideration. The average mobility of ions lies around  5.10-" mVU.s,
 which is a factor 10 greater than that of the electro-osmotic mobility.
 Therefore, the energy  necessary  to  move  all  ions  over  an average
 distance of  1 m through aim2 soil section its 10 times less than with
 electro-osmosis.

 To calculate the  energy necessary to dispose of the  contaminants within
 1  m3 of soil,  the following factors  are of importance :

 -  the chemical  form of  the contaminants;
 -  the concentration of  the contaminants;
 -  the required concentrations  of  the contaminamts;
 -  the behaviour of the  contaminants  at  different  pH-levels;
 -  pH-control around the electrodes within the soil;
 -  removal  of   the contaminants and particles at the respective
   electrodes;
 -  supply of a  conditioning solution  to replace the removed  contaminants
   and other particles at  the electrodes;
 -  processing of the contaminated solution removed at  the electrodes.


 The application of electrokinetical phenomena in practice

 Up  to  a  few  years  ago  the  most important application of electro-
 kinetical phenomena with respect tot the  soil had  been the dewatering
 of clays  by electro-osmosis.  Apart from that experiments and research
 in the USA (Collopy, 1958) and the USSR  (Vadyunina et  al., 1966-1975)
 were aimed  at developing  a technique to remove accumulated salts from
 agricultural terrains.
 Experiments on a very  small scale  both in  the laboratory  and in the
 field  are  documented  by  Hamnet  (1980),  Agard  (1981) and Warfield
 (1982). These  experiments were  aimed at  the removal  of heavy metals
 from the  soil. Though the experiments started promisingly, the authors
reported problems  around the electrodes (chemical  precipitates) after a
 certain  time  period,  which  influenced the process in an adversative
way. Especially the changing of the pH around  both electrodes influen-
ces  the mobility of the heavy (and also lighter) metals.
                                60

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                          KINETICS
                                          '' 'contaminated
                                                             GENERATOR
                                                             (WHAM

                     circulation system

                     current  supply

            — — — -  boundary of electrokinetical treatment
Fig. 1   : Schematic  representation of ER-field unit  and
         electrokinetical transport in the soil
                                61

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                           KINETICS
 Electrokinetical Installation

 Geokinetics  has  found  a  solution  to  these  problems. Both for the
 laboratory and the  field  an  electrokinetical  installation  has been
 developed, which  controls the chemical reaction environment around the
 electrodes. The electrokinetical processes  are  monitored  and managed
 actively, thus averting adverse effects.

 The core  of an  electrokinetical installation (fig.  1) consists of the
 electrode-series and their housing.  These can be installed in principle
 at any  depth, either vertically or horizontally. Both the cathode- and
 anode housings are interconnected  and  form  two  seperate circulation
 systems (one for the cathode,  one for the anode), filled with different
 chemical solutions.   In these   solutions the  contaminants are captured
 and brought  to a water purification facility,, installed in a container
 together with the solution tanks and measuring and monitoring devices.
 The energy is supplied by a generating-set or taken from the main.

 The  consequence  of  this  set-up  is,  that electro-reclamation can be
 applied both for in situ remediation of contaminated  soil (fig.   2)  and
 for on-  or off  site remediation of excavated polluted soil or scooped
 out river slush.
 Laboratory experiments

 The method of  electro-reclamtion has  been  tested  on  the  basis of
 numerous  laboratory experiments. They  focussed on  important parameters
 like  kind of current, strength of current, voltage,  moisture content,
 chemical   additives and   the  like.  Besides, the  effectlviness of the
 method as regards certain  soil- and heavy-metal types has been examined
 with  the  help  of several  simulation  experiments (clay, peat, fine
 argillaceous sand polluted with As, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb,
 Sb, Zn).   They rendered  also a good  insight  into the energy demand and
 the time  duration.  Some results are presented in table 1 and figures 3a
 and 3b.
Soil type
Peat
Pottery clay
Fine argil-
laceous sand
Clay

Metal
Pb
Cu
Cu
Cd
As

Cone, before
(ppm)
9000
500
1000
275
300
Table 1.
Cone, after
(ppm)
2400
200
100
40
30

Energy
(kWh/ton)
56
56
14
110
115

The next table shows the results before and  after treatment  of a soil
sample of fine argillaceous sand, contaminated with several metals.  The
energy demand amounted to 30 kWh/ton.
                                  62

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                                   KINETICS

                                                               n
A)   Remediation  of  residential  areas
B)   Remediation  of  industrial areas
0   Remediation/fencing of hazardous waste  sites
D)   Preventive  electrokineHcal fence around  potentially  hazardous industrial complexes
Fig. 2   : Some applications of in situ  Electro-Reclamation
                                           63

-------
                           KINETICS
Soil type      Metal     Cone, before   Cone, after
                              (ppm)          (ppm)
                                                             Decrease
Fine argil-
laceous sand





Cd
Cr
Ni
Pb
Hg
Cu
Zn
319
221
227
638
334
570
937
< 1
20
34
230
110
50
180
99
91
85
64
67
91
81
                                Table 2.
                                             Average :
                                                                  83
 Table 3 lists the results of a laboratory  experiment with  a  sample  of
 mud,  dredged  from the  river Weser  in Germany.   The energy demand for
 this  experiment amounted to 100 kWh/ton.
Soil type
River slush







Metal
Cd
Cu
Pb
Ni
Zn
Cr
Hg
As
Cone, before
(ppm)
10
143
173
56
901
72
0.5
13
Cone, after
(ppm)
5
41
80
5
54
26
0.2
4.4
Decrease
( % )
50
71
54
91
94
64
60
66
                               Table  3.
                                                                 69
Fieldexperiments
Fieldexperiment 1

The first fieldexperiment took place alongside  part of  a waterbearing
ditch, on  one side bordered by a former paint-factory and on the other
side by open grassland. The bank on the  latter part  was heightened by
sediment  dredged  from  the  ditch. This sediment was heavily polluted
with metals in the form of paint residuary. The raised  sediment layer,
height 20  - 50  cm, length  70 m  and width  3 m,  contained Pb and Cu
concentrations  up  to  10,000  ppm  and  5,000  ppm  respectively. The
original  peat  soil  underneath  was  contaminated by leaching of this
overlying layer with Pb-concentrations ranging  from  300  ppm  to more
than 5,000  ppm, while  Cu-concentrations were  in the  order of 500 to
1,000 ppm.

A preceding laboratory test with a sample of  the sediment  reduced the
concentration of Pb from * 9,000 ppm to * 5,000 ppra and that of Cu from
« 4,500 ppm to « 1,600 ppm, all within a time period of 320 hours.
For  the  fieldexperiment  one  cathode-  and   one  anode-series  were
installed both with a length of 70 m and a mutual distance of 3 m.
                                 64

-------
 0.
 a.
     1000
      800
I    600-j
 ro
 2    400-
 c
 o

5    200-j
                                  KINETICS
          0     20   40   60    80    100   120   140   160

                              time  (hours)
Fig. 3a   : Decrease of Copper during elecfrokinetical treatment
          of contaminated  pottery  clay
Q.
O
'•^
ro
c
o
250


200-


150-


100-


 50-


  0
                5          10

                time (days)
                                             15
Fig. 3b   : Decrease  of  Cadmium during electrokineticat treatment
          of contaminated fine argillaceous sand
                                           65

-------
                               •-377?
                           K I N E T I C S
 The cathode  was installed horizontally, while the anodes were implaced
 vertically into the soil about 2 m apart.  On the  basis of  the energy
 consumption during the laboratory test the fieldexperiment was confined
 to 430 hours.
 The changes in Pb- and Cu-concentrations were monitored  at 26 sampling
 locations, sampled  at regular intervals at several depths (10,20,30,40
 and 50 cm below groundsurface).  The following table  lists part  of the
 analysis-results for  Cu and  Pb within the peat at a depth of 30 to 40
 cm below ground surface. The spatial distribution of  the pollutants at
 the beginning and at the end of  the test are shown in figs. 4a and 4b).
Sample
(30-40
1
1
2
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
point Metal
cm b.gs)
Pb
Cu
Pb
Cu
Pb
Cu
Pb
Cu
Pb
Cu
Pb
Cu
Pb
Cu
Pb
Cu
Pb
Cu
Cone, before
(ppm)
440
185
3900
540
> 5000
1150
> 5000
475
> 5000
1170
> 5000
580
3780
410
380
35
340
50
Cone, after
(ppm)
110
35
700
220
560
580
2450
250
610
230
300
45
285
30
180
15
90
15
Decrease
( % )
75
81
82
59
89
50
51
47
88
80
94
92
92
93
53
57
74
70
                               Table 4
Average :
                                                                 74
Fieldexperiment 2

The second, fieldexperiment was carried out on the site of a galvanizing
plant.  According  to  preceding  investigations  the soil (sandy clay)
around the plant was contaminated with  Zn to  a depth  of 40  cm below
groundsurface. In  the upper  10 cm  Zn-concentrations were reported to
have a maximum of 3,000 ppm.  At greater  depths Zn-concentrations were
indicated as being in the order of 500 ppm.

For the experiment an area was selected with dimensions of 15 m x 6 m x
1 m. Two cathode-drains were  installed  at  a  depth  of  50  cm below
groundsurface, while 33 anodes, divided along 3 rows were implaced in
holes  of  1  m  depth  with  a  mutual distance of 1.5 m. The distance
between the cathode- and anode-series was also 1.5 m.

Energy was supplied by a 100 kVA generating set. The resistivity of the
soil was 5 iim. The installation was calculated for a DC-supply of
8 Araps/mz of soil, which should result in a potential drop of 40 V/m.
This potential drop could not be maintained during the whole period.  As
a result of some material problems it was neither possible  to maintain
a 24 hour energy-supply to the soil.
                                  66

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                           KINETICS
-   3m   -


 cathode-series

 anode-series
                                Cu>500ppm

                           1005000ppm

                 0   600a. Decrease of Cu
         4b. Decrease of Pb
                                      67

-------
                          KINETICS
 Within 2 weeks temperature rose from 12 °C  to an average of 40  °C. As  a
 consequence soil resistivity decreased to 2.5 Sim and the potential drop
 to  20  V/m  with  an  average  strength  of  current of 8  Amps/m2.  The
 effective energy-supply per 1000 kg of soil amounted to 160  kWh during
 the 8 week period.

 Changes in  Zn-concentration were  monitored at  12  sampling locations,
 which were sampled at 3 different depth intervals  (10,  30   and 50 cm).
 Changes In  groundwater concentration were monitored  in 2 observation
 wells. In table 5  and fig.   5 the  analysis-results are given for  the
 depth interval of 30  cm.  .
Sample point Metal Cone, before
(30 cm b.g.s.) (ppm)
1 — , 5120
2
3
4
5
2030
1600
2320
2450
6 > Zn 4390
7
8
9
10
11
1960
3250
2400
70
150
12 — 1 120
Cone, after
(ppm)
4470
1960
800
2320
2450
2360
940
1960
2000
30
120
80
decrease
( % )
13
3
50
0
0
48
52
40
17
57
20
33
                               Table 5.
Average :
20
The  energy  demand  for  this  test  amounted  to  160 kWh/ton. At the
beginning of the test  the highest  Zn-concentration amounted  to 7,010
ppm with an average of 2,410 ppm over the whole area. At the end of the
test the  highest Zn-concentration  was 5,300  ppm and  the average had
been decreased  to 1,620.  The concentrations  of Zn,  Pb and Cd in the
groundwater and the filtercake are presented in the tables 6 to 8.

A total of some 1000 kg of filtercake was produced with an  average Zn-
content of  117 g/kg.  This comes  to a  total removal of some 50 kg of
zinc, assuming an average moisture content of the filtercake of  60 % .
A rough mass-balans could be summarized as follows :

- treated volume of soil : 15 x 6 x 0.5 x 3/4 = 34 m3 (1/4 of the area
  did not show increased Zn-concentrations).
- Weight : 34 m3 x 1.8 = 61 tons.
- Weight of filtercake : 1000 kg.
- average moisture content : 60 %
- total dry matter :  400 kg.
- average Zn-concentration : 117 g/kg.
- amount of zinc removed : 47 kg
- removed per 1000 kg of soil : 47 x 10V61 x 103 = 770 ppm.

The  last  value  is  in  the  same  order  of magnitude as the average
decrease in Zn-concentration (2410 ppm -1620 ppm = 790 ppm).
                                  60

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                             K I N E
An important  outcome  of  the   test   was  the  relatively  high energy
consumption against  a rather   low Zn-mobility.  This  was the result of
the high buffering capacity of  the soil,  caused by the  presence of NH3
and  NH«C1   (as  was  established   later),   which  is   used  during the
galvanizing process. During a following  laboratory  test  with  a soil
sample from  the area  it was found that  the energy necessary to reduce
Zn-concentrations below the 200 ppm level  would amount  to 500 kWh/ton
of  soil.   With  an  unchanged  power-suplly of 100 kVA this would mean
tripling the time period of 8 weeks to 24 weeks.
Metal : Zn
sample treatment : not
date
24-10-88
01-11-88
09-11-88
17-11-88
25-11-88
30-11-88
24-10-88
01-11-88
09-11-88
17-11-88
25-11-88
30-11-88
obs. well
1
1
1
1
1
1
2
2
2
2
2
2
Pb
Cd
acidified
Zn
Pb
Cd
acidified
ppm
200
120
130
172
130
120
10
1.5
2.5
6
2.8
4
0.09
0.07
0.06
0.07
0.17
0.13
0.17
0.09
0.06
0.03
0.03
0.09
0.06
0.00
0.02
0.03
0.03
0.03
0.02
0.09
0
0
0.01
0
270
140
160
198
180
150
40
2
3
8
5.8
5.5
1.4
0.09
0.17
0.11
0.22
0.16
0.34
0.15
0.15
0.07
0.18
0.14
0.07
0
0.02
0.04
0.03
0.03
0.02
0
0
0.01
0.01
0
               Table 6. Zn-content (ppm) of the groundwater  in obser-
                       vation wells 1 and 2.
Metal : Zn
date
24-10-88
09-11-88
17-11-88
25-11-88
30-11-88

136.9
199
99
89
61
Pb
g/kg
1.9
1.1
2
1.5
0.58
Cd moisture cnt

0.
0.
0.
0.
0.

34
18
12
16
11
in X



78

               Table 7.  Zn-content (R/kg) of the filtercake during
                       Electro-Reclamation.
Metal : Zn
date
30-11-88
Pb
Cd
ppm
30
0.6
' 0
                     Table 8.  Zn-content  (ppm)  of the solution in
                             the anode-circulation  system.
                                69

-------
                             KINETICS
 E
 ui
    Zn-concentrations 30 cm below g.s.
    (24/10/88)
      Zn-concentrations 30 cm below
      (16/12/88)
                                                                            g.s.


Zn>tOOOppm        ||| 2000 250ppm
Fig. 6  :  Results of remedial action project 1
      As-concentrations  1 m  below  g.s.
      (28/^/89)

HJ30
-------
                          KINETICS
Remedial action Project 1

The first  'official'  Electro-Reclamation project started at the end of
January 1989. It concerned an As-pollution  on  the  site  of  a former
timber-impregnation  plant.  After  a  fire  in 1984, which destroyed a
large part of the plant, it was decided not to rebuild the plant. After
dismantling the  same a  'statement of  unpolluted soil'  was needed in
order to allocate the land to building plots. A following investigation
established the  presence of As-concentrations up to several 100 ppm in
part of the heavy clay soil to a  maximum depth  of 2  m. Cause  of the
pollution  was  attributed  to 'Superwolmansalt D' (NaaHAsCU.THaO), used
for impregnation.

In April 1988 Geokinetics was requested to investigate  the possibility
of remediating  the soil by Electro-Reclamation. A following laboratory
test with a soil sample reduced the As-concentration  of 300  ppm to 30
ppm against  an energy  consumption of 115 kWh/ton. An additional field
investigation delineated the pollution to an  area  of  10  m  x  10 m,
contaminated to  a depth  of 2  m and  an adjoining area of 10 m x 5 m,
contaminated to a depth of 1 m. Total volume of polluted soil  : 250 ms
(= 450 tons).

The project  started in  January 1989. Along the length of the polluted
area 4x2 cathode-drains were installed : one at a depth of 1.5  m and
the other at 0.5 m. The cathode-series had a mutual distance of 3 m.
In between 36 anodes were implaced in the soil, divided along 2 rows of
14 and 1 row of 8 pieces. Within the area  of 10  m x  10 m  the anodes
were installed  to a  depth of  2 m  below ground surface. In the other
area of 10 m x 5 m the depth of the anodes  was limited  to 1  m depth.
All anodes were placed at a mutual distance of 1.5 m.

On the  basis of  both the  laboratory test and the field investigation
the duration of the Electro-Reclamation period  was calculated  to last
50 (24 hour) days, using an energy-supply of 200 kVA (= 44 kW effective
into the soil.

At the beginning the  resistivity  of  the  clay  was  10  Qra  and soil
temperature at a depth of 0.5 m was 7 °C. After 3 to 4 weeks temperatu-
re had risen to an average of 50 °C, while the resistivity decreased to
5 iim. The original potential drop of 40 V/m decreased accordingly to 20
V/m with an average current-strength of 4 Amps/m2 (total crosssectiornl
area being 110 mz).

Changes  in  As-concentrations  were  monitored  at  10  fixed sampling
locations and numerous  randomly  distributed  sampling-points.  Of the
fixed locations,  2 were  sampled at  0, 0.5, 1, 1.5 and 2 m depth. The
others at 0, 0.5 and 1 m depth. The analysis-results at a depth of  1 m
below  ground  surface  are  listed  in  table  9  and fig. 6. The last
sampling date being April 30th.

With an average As-concentration over the whole area of 110  ppm before
the process  started, the  total As-content  amounted to some 50 kg. On
April 30, 3/4 of the area  showed As-concentrations  below the required
30  ppm  boundary.  One  spot  remained,  however, with relatively high
As-concentrations. Calculations showed,  that  some  25  to  30  kg of
arsenic had been removed.
                                 71

-------
                                      KINETICS
                                         150 m
                     anode-series (vertical)
                 O  cathode-series  (vertical)
                     flow P^hs of positively charged contaminants
  Fig 7a.  : Set-up  of  electrokinetical fence in soil with low  permeability
   L
              -•    anode-series (vertical)
              -O   cathode-series (vertical)
              *-    flow  paths of positively charged  contaminants

                    direction  of  groundwater  flow
Fig. 7b   :  Set-up of elecfrokinetical fence in  soil with moderate to high permeability


                                                72

-------
                          KINETICS
Because of the time pressure it was decided tot continue the ER-process
for another two weeks, whereafter the  soil, which  at that  time would
still show  too high  As-concentrations, would have to be excavated and
removed. When the process was stopped  on  May  12  and  the excavation
began, many  metal objects  like tins,  barrels, concrete-iron etc were
found. These objects were  supposed to  hav been  removed by  the owner
before the electro-reclamation started, but obviously, had failed to do
so.

The discrepancy, therefore, between  estimated  and  real energy-demand
(and thus  elapsed time) was caused by these metal objects, left behind
in the soil. These objects function as preferential  flow-paths for the
electrical current  and delay  the movement  of the pollutants in their
vicinity, as first all the iron objects will go into solution.
    Sample-point
    (1m  b.g.s.)
Metal     Concentration  Concentration  Energy
           on  24/1/89    on  30/4/89   (kWh/ton)
1 -,
2
3
4
5
6
7
8
9
10 -
385
40
250
310
> As 50
75
40
175
40
60
250 -,
< 20
< 20
190
< 20
30
< 20
< 20
< 20
< 20 J




> 150





                               Table 9.
Other applications
Electrokinetical fencing

The  electrokinetical phenomena occurring when the  soil is electrically
charged,   can  also  be   used  for  fencing  purposes.  These so-called
electrokinetic  fences  can be installed either at refuse-sites/factory
complexes,  where soil  pollution has already been ascertained,  or where
soil pollution  is  likely to occur. Depending on the local geohydrologi-
cal  situation and  the  character of the soil, the elctrode configuration
can  be such that :

- the elctrokinetical  transport  is  directed towards the source of the
pollution (fig. 7a). The cathode-series   is  situated  nearest  to the
source of  pollution.  Such  a set-up should be applied in less permable
soils without substantial groundwaterflow  ( < 1 m/year).

- the contaminants, which are carried along  with  the  groundwater flow
are  diverted, collected  around the electrodes and  periodically removed.
In this case the   cathode-series  is  farthest away from the  source of
pollution and  cathode-  and anode-series are installed perpendicular to
the  direction of groundwater flow. Such a  set-up should be applied when
 the   soil  and/or   subsoil   is  relatively permeable  (groundwaterflow
velocity > 1 m/year).

                                 73

-------
                           KINETICS
Desalination, of arable land

Salination of arable land is a common problem in those countries, where
precipitation  is   generally  low   and  evapotranspiration  high.  In
combination with relatively high groundwater levels   (coastal areas and
river-lowlands), soils  of low  permeability and   irrigation water with
high total dissolved solids,  the  accumulation  of   salts  in  the top
layers prohibits further agriculture.

The most  common technique for landreclamation. consists of the lowering
of the groundwatertable and/or drainage of the soil   by means  of wells
and/or horizontal  drains. The  soil is  then frequently irrigated with
relatively fresh water, thus leaching the salts from  the soil. However
the  low  permeability  of  the  soil  hampers  more  often than not the
percolation of the leachate to the deeper layers.

By applying electrokinetical processes these problems can be overcome,
as  clay  and  argillaceous  soils are specifically suited for electro-
reclamation.

The As-remediation project mentioned afore showed,  that after electro-
kinetical  treatment,  the  permeability  of  the  heavy  clay-soil had
increased significantly. When furthermore gypsum is added at the anode-
solution, the soil structure will be improved even more and higher crop
production will be obtained (Collopy, 1958).
Cost estimates
Electro-Recalamation

Fig. 8 shows a set of graphs depicting remediation cost per ton of soil
as a  function of  remedial action  time (fig. 8a) and as a function of
the measure of contamination (fig. 8b),  assuming a  polluted area with
dimensions of  500 m  x 100 m x 1 m. From the graphs it is evident that
short remediation  periods and  highly polluted  soil (low resistivity)
require  a  high  amount  of  energy, having the greatest effect on the
costs.

In practice, however, there is a limit to the electrical  current which
can  be  put  into  the  soil.  For  every specific case, therefore, an
optimum must be calaculated for energy supply and time duration.
Electrokinetical fencing

In fig. 9 the  energy  costs  per  year  are  given  as  a  function of
groundwater flow  velocity (fig.  9a) and  as a function of the rate of
pollution (fig. 9b), assuming an electrokinetical fence of 500 m length
and 10 m depth.
                                 74

-------
                               I  I  I  >
                              >or-K
                              <  <»  3 c-
                              "  ~°  3 3
energy  costs per annum (us $  x  1000)
                                                  o    o
                          ii.no
                                 "
            U3 10  il

            •••
            u> (/>  n
            -r -r
            VI I/I  o
            (/I  (A  (V
            C  C  n
             »
            a. c  n
            » 3  rr
               a. n
•<   3 n  :
 "   &£!
 Ln   £;
 «=•   ^ o ,

                                                                                               costs  per ton  (us ;)
                                                                             > u
                                                                                                                        ^ ^. 2. «
                                                                                                  r. n I*
                                                                                                  O o •«•
                                                                                                    §' o
                                                                                                    ? "~
                                                                                                    -i   .
                                                                                                                                         n
                                                                             §
                                                                             (A
                                                                O
                                                                I
                                                                     s;
                                                                     o  '
                                                                     Q-
                                                                          § ><
                                                                       '?•    -
                                                                        s    §
                                                                        2.    3
en
                                                                                                  5'   !i
                                                                                                  =    5
                                                   energy costs per annum  (us  t x 1000)
                                                                                                                                                  costs per  ton (us
                                                                                                                                                                                     n
                                                                                                                                                                                     V)
                          a.
                           3
                           N
                                                °
                                                                                                                                         <   t~
                                                                                                                                         =V   o
                                                                                      o
                                                                                      3-

                                                                                      3

-------
 In areas of low groundwater flow velocity (clciy,  argillaceous sand)  and
 low soil pollution,  the  yearly  energy  costs of  an electrokinetical
 fence  are  insignificant.   This  changes rather  quickly,  when the soil
 becomes more permeable  (sandy  formations)   and   the  groundwater flow
 velocity Increases together with the concentration of the  contaminants.

 For  relatively  high  groundwater  flow  velocities  a combination of
 hydrological measures and electrokinetical  techniques will   render  the
 most economic results.
 Desalination of arable land

 Preliminary cost estimations amount  to US  $  1000  to  2000 per ha.
Geokinetics
Veerkade 7
3016 DE Rotterdam
the Netherlands
                                  76

-------
                  VACUUM EXTRACTION TECHNOLOGY

                  SITE Program Demonstration at
          Groveland Wells Superfund Site, Massachusetts

                      James J. Malot, P.E.
                            TERRA VAC
                      Princeton, New Jersey
Abstract
     Vacuum extraction  is an  in-situ or ex-situ treatment process
for  cleanup of soils and groundwater contaminated with  volatile
'organic  compounds   (VOCs), liquid-phase  hydrocarbons  or  semi-
volatile compounds.  The process of removing VOCs from the vadose
zone  using vacuum  is a patented process.  Demonstration  of  the
Vacuum  Extraction  Technology was conducted under the EPA  Super-
fund  Innovative  Technology  Evaluation  (SITE)  Program  at  the
Groveland Wells Superfund site  in Groveland, Massachusetts.   The
demonstration  included an eight-week pilot test to removed  VOCs
(mostly TCE) from the underlying soil and groundwater.

     The  subsurface conditions   included  multilayered  glacial
deposits consisting of  sands, silty sands and clays.  Groundwater
was 27 feet deep with a perched water table at about  10 feet.   A
multi-layered  vacuum  extraction and monitoring system  was  in-
stalled and operated sub-zero weather in  northern Massachusetts.

     Objectives  of the pilot program included testing  of  soils
before, during and  after  implementation of the vacuum  extraction
process.   The  effectiveness   of  the process  was  monitored  by
measuring subsurface vacuum,  rates of flow, rates of VOC  extrac-
tion and adsorption on  activated carbon.  The system was designed
to operated on the  fringe of  the contaminant plume and to quanti-
fy the  level of cleanup that  could be achieved by the process  by
using barrier wells to  prevent  the migration of contaminants from
the primary source  area into  the demonstration area.

     Results demonstrated the effectiveness of the vacuum extrac-
tion process to clean up contaminated soils.  Data from the pilot
test  also demonstrated that  contaminant  distributions were  dif-
ferent  than originally  suspected from the Remedial   Investigation
(RI>.    In  the area at  the  fringe  of  the  contaminant  plume,  soil
concentrations  were reduced  more  than  95%  to  non-detectable
levels.   Accordingly,  evaluation of the process  dynamics  and
cleanup  rates  were adjusted to reflect  the  actual  subsurface
conditions.  Additional data  from  subsequent cleanup  work at  the
site  is  presented  to further  evaluate- the demonstration program.

     The objective of evaluating "How clean  is clean?"   is  ad-
dressed  with respect to  the  vacuum  extraction process.   Results
from other  sites  where  vacuum extraction  has been applied  is also
presented.  Results indicate  that  vacuum  extraction  technology  is
widely   applicable for  cleanup  of  soils and  groundwater  that  are
contaminated with VOCs.

                                77

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Vacuum Extraction Technology
INTRODUCTION

     Vacuum  extraction  technology effectively  removes  volatile
and semi-volatile compounds from  soils and groundwater.   Removal
of  liquid-phase hydrocarbons floating on the water  table  using
vacuum  extraction technology is  faster and more  effective  than
traditional  approaches.  Vacuum  extraction is  typically  imple-
mented  in-situ,  however, treatment of excavated soils  on  site
using  vacuum extraction technology  is also  effective.   Ground-
water can be removed  simultaneously from vacuum extraction  wells
to  further  enhance  recovery of groundwater  contaminants  and
reduce the time frame for total cleanup.

     Vacuum  Extraction  Technology was originally  developed  by
Terra  Vac.   Since its  inception more than five years  ago,  the
technology  has been  widely used  to cleanup soil and  groundwater
contaminated with volatile organic compounds 
-------
Vacuum Extraction Technology
soil and groundwater to nondetectable levels.
VACUUM EXTRACTION PROCESS

     Under normal static conditions within the soil matrix,  VOCs
are  partitioned  between  four possible phases:   1)  vapor,  2)
liquid,  3) dissolved  in soil water, 4) adsorbed to solid  parti-
cles.    These four phases define the aggregate contaminant  con-
centration in the subsoils.

     The vapor phase partitioning is a complex function of  water
content,  organic  content,  .solubility,  temperature  and  vapor
pressure.   It is not  necessary to define the exact  relationship
between soil concentration and vapor concentration as a  function
of time in order to understand that reductions  in extracted vapor
concentrations are driven by continuous partitioning to the vapor
phase  which corresponds to  reductions in   soil  concentrations.
Furthermore, as concentrations in soils are  rerf-.-.ced  significant-
ly,  vapor phase partitioning is generally controlled  by  Henry's
Law.                                    '

     As  vast  volumes of  soil vapor are removed  by  the  vacuum
process,  fresh air naturally recharges the  vadose zone from   the
surface.   Fresh air moves through  the contaminated zone as  VOCs
are  partitioned from the soil matrix to the  vapor phase and  move
to the extraction wells.   With vacuum  induced  volatilization   and
air  stripping of the soil  matrix, cleanup occurs continuously.

     As  contaminant   vapors are  removed from  the  subsoils  pore
volume,  the  three other phases  (liquid, adsorbed and  dissolved)
of   VOCs vaporize  in place,  further reducing the  aggregate   soil
concentration.   Since VOCs  vaporiz'e readily,  the vacuum   extrac-
tion process  continually drives  the contaminants within  the   soil
matrix to  the vapor  state.

     Progress   of   the vacuum   extraction   soil  decontamination
system  can   be  monitored  by the  concentration of   the   extracted
vapors.  Since  vaporization  occurs  rapidly  within  the  soils,   the
soil vapors  beyond  the immediate  vicinity  of the extraction   well
are  near equilibrium with  respect to the majority  of  the contami-
nants  contained in  the soil  matrix.

      As VOCs are vacuum extracted from the subsoils,  the  removal
rate declines with  time,  indicating cleanup of the soils.   During
 the  vacuum extraction process,  vapors extracted at the  wellhead
 represent   essentially an aggregate soil-gas  concentration  near
 the  screened interval.  Under static conditions,  the  concentra-
 tion of VOCs in the vapor phase  is proportional  to the aggregate
contaminant concentration in the soil.

      The first step of vacuum extraction design is delineation of
 the  extent and magnitude of the soil contamination  and  liquid-
 phase  contaminants   that  may be floating on  the  water  table.
 Vacuum  extraction wells are designed with a vacuum-tight   seal
                                 79

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Vacuum Extraction Technology


near the  surface and an extraction  zone  (screen) corresponding to
the profile of subsurface contamination.

     The  spacing of vacuum extraction wells  is critical to  effi-
cient  remediation.   Depending on  the depth to  groundwater  and
soil  type,   the radius of influence of  an  extraction  well  can
range from tens of feet to hundreds, of feet.,  Soil  permeability,
porosity, moisture content, stratigraphy and depth to groundwater
are  important factors in determination  of the radius  of   influ-
ence.

     Vacuum extraction technology is effective in treating  soils
containing virtually any chemical with a volatile character.  All
of  the   volatile  priority  pollutants  and  many  of  the  semi-
volatiles have been successfully extracted with the vacuum  proc-
ess.  However, metals (except mercury),  heavy oils and PCB's will
remain  in place as the volatile compounds are extracted  by  the
process.  .   Dual vacuum extraction of groundwater and vapors has
been effective at restoring groundwater  quality to drinking water
standards within short periods of time.

     For  those  sites with numerous types  of  compounds   (i.e.,
VOCs,  PCS,   pesticides and metals) a phased  approach  is  often
required.   In  these cases, it is prudent t:o remove  VOCs  first
using  vacuum extraction so that other technologies can  then  be
applied more  cost effectively and safely.  For example,  chemical
treatment or  incineration of soil, which require excavation,  the
health  risk  of excavation is minimized  if the majority  of  VOCs
are  removed  first, in-situ, by vacuum extraction.  Many  methods
used  to  chemically stabilize metals are  more  effective  after
vacuum extraction has removed VOCs.

     Vacuum   extraction is an effective  means of removing  hydro-
carbons  floating  on  the  water  table.   Compared  to  typical
double-pump   systems, skimmer pumps and  air  displacement  total-
fluids  product  recovery systems, vacuum extraction  is  faster,
more  effective  and  low cost per  gallon  of  product  removed.
Liquid-phase hydrocarbons are removed without pumping groundwater
so that separation and treatment of large volumes of contaminated
water is eliminated.

     Where contaminants are within the saturated zone and ground-
water  is  relatively shallow (i.e., less than 30  feet  deep)  a
"dual  extraction" approach is effective.  Dual extraction  is  a
term  used to describe the process of  simultaneously  extracting
groundwater and vapors under vacuum using the same well.   In  the
simplest  form,  operating  a submersible pump  within  a  vacuum
extraction  well  will  lower the water  table  and  increase  the
effective unsaturated zone in which the vacuum extraction process
will vaporize contaminants.

     Simultaneous  extraction  of groundwater  and  vapors  under
vacuum has several benefits that enhance the rate of  groundwater
cleanup.    First,  the rate of contaminant removal increases  com-
pared to groundwater extraction alone since contaminants have two
                                80

-------
Vacuum Extraction Technology


pathways  for   removal:  aqueous  phase and vapor.   Even  in  areas
where  groundwater  movement beneath the water table is  the  only
source of contamination,  the  dual  extraction process often yields
the  same mass  flux  (i.e.,  pounds/day) from the vapor phase as the
aqueous  phase.  This indicates  that substantial  partitioning  is
occurring  in the transition zone and capillary fringe.  In medium
to   low  permeability aquifers the  maximum rate at  which  ground-
water  can  be extracted from  a given well increases two to  three
fold using  dual extraction.   The net effect of these two phenome-
na   can  yield  a six-fold increase in  the  overall  contaminant
removal  rate,  and hence, a  six-fold reduction in the  time  re-
quired to  reach clean-up objectives.


 Subsurface Conditions at the  Demonstration Site

      The  Groveland site is underlain by glacial  deposits.   The
 thickness  of the unconsolidated deposits under the site is on the
 order of 32 to SO feet. In the pilot test area the upper  10 to 16
 feet  consist  of fill and glacial outwash sands.  A  dense  clay
 layer,  3  to 7 feet thick,  is observed below the sands,  but  is
 discontinuous throughout the site.  Glacial till is present below
 the  clay.  The water table is roughly 25 feet deep in  the  test
 area.

      A multi-layered vacuum extraction and monitoring system  was.
 installed, as  shown  in Figure 1,  to segregate the upper sand zone
 from  the  lower till.  The vacuum extraction  system consisted  of
 four extraction wells and four monitoring wells; each was capable
 of  extracting contaminants separately  from  above  or   below  the
 clay.  This   provided effective hydraulic separation  of   the  two
 more'permeable units (sand and till) and allowed  differentiation
 of  the  contaminants extracted from the two  zones.   Activated
 carbon was used to  control emissions from the site.

       Volatile organic  soil contamination is  generally constrained
 within  soils  above the  clay lens,  according to   the  Record  of
 Decision.   The contamination begins just below  land  surface  and
 extends  down to the top  of  the clay lens.   Below  the  clay  lens
 contamination  levels  are generally less than 100  ppm.    However,
 one "hot  spot" of  soils containing 1500  ppm was  observed   distant
 from  the   major   source  area and below  the  clay.    The   primary
  source  area was considered to be  beneath the storage  area of   the
 manufacturing  building  located  at the site.    Accordingly,   the
 SITE  demonstration  was designed  to focus on the periphery of  the
 primary zone of contamination.
  Pilot Test Objectives

       The  objectives  of the pilot test was  to
  vacuum extraction technology would effectively:

       - remove VOCs from the vadose zone,
demonstrate  the
                                 81

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 Vacuum Extraction Technology


      - remove VOCs from various soil type (sands, and clays),

      - correlate declining recovery rates and cleanup levels,

      - correlate VOC concentrations in soils with extracted
           vapors.

      Several  constraints were imposed that impacted  the  design
 and  operation of the vacuum extraction system.    One  constraint
 was to not clean up the site, although it was important to demon-
 strate  how clean the process could decontaminate the soils.   In
 addition,   the time frame for cleanup had to be  relatively  short
 in order to minimize costs.

      The  size of the soil volume to be treated  was difficult  to
 contend  with  since the in-situ treatment process did  not  lend
 itself to  segregating the subsurface treatment process to a small
 test area.   Evaluating the effects of the subsurface dynamics and
 the  objective of judging "How clean is clean?"  was  a  challenge
 for the short term,  in-situ~demonstration.

      The location of the vacuum extraction pilot test was select-
 ed to minimize interference  with the on-site manufacturing opera-
 tions,  to  be near the edge of the contamination,  and to be acces-
 sible  during  the  mid-treatment  and  post-treatment  sampling.
 Since the  contamination was  wide-spread but predominantly located
 beneath a  building at the demonstration site,  it seemed plausible
 to install  a line of vacuum  extraction wells to  act as a  "barri-
 er",   isolating the high level  contamination from   an  extraction
 well  installed in the less contaminated area,  thus,  focusing  the
 evaluation  on the effectiveness achieved in the  low level  concen-
 tration area.   The presumption  was that the contaminant distribu-
 tion  was sufficiently defined to  predict the movement of contami-
 nants in the subsurface during  the demonstration.

      The final  objective in  the SITE demonstration for the vacuum
 extraction   technology  was   to evaluate "How clean  is  clean?"
 Several  test  methods were used including TCLP,  soil   concentra-
 tions  (headspace and Contract  Laboratory methods),  shallow  soil
 gas   surveys and  monitoring  subsurface contaminant vapor  concen-
 trations with  time.
RESULTS

     The  subsurface  contaminant plume within the soils   in  the
demonstration  area was erratic and somewhat different  from  the
data  available  from the Remedial  Investigation.   The   highest
concentration measured during the baseline sampling of the demon-
stration  was within the presumed "clean" zone.   The  extraction
well from the presumed "cleaner" area recovered more VOCs  than  a
barrier  well  located closer to the primary source  area.   This
critical  difference between actual and presumed  conditions  re-
quired  a refocusing of the results with respect to  the  barrier
design and actual results achieved.
                                82

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Vacuum Extraction Technology
     Recovery rates from vacuum extraction wells varied  signifi-
cantly, ranging initially from 9 to 77 pounds/day.  Higher recov-
ery rates were obtained from the shallower zone where the highest
soil  concentrations were observed.  Recovery rates decline  witn
time except where the contaminants were extracted from the  wells
near the primary source area.

     During the SITE demonstration, Terra Vac removed about   1300
pounds  of  VOGs from the subsoils during the  eight  week  pilot
test.  These data were derived from flow and concentration  meas-
urements  taken during the vacuum extraction test.   The  results
were confirmed by analysis of the activated carbon  that was   used
to collect extracted VOCs.

     Results of the demonstration  indicated contaminant  levels in
soils   on  the  order of  10  ppm  were   reduced   to   non-detectable
levels,  as depicted in Figure 2.   In  areas with higher contamina-
tion   (i.e.  greater than  100 ppm in  soil) contaminant  concentra-
tions   in   soils  were reduced about  967. during  the  8   week   pilot
test.

      In general,  reductions  in  VOC concentrations throughout  the
 shallow  soils  at the  site were observed.   Figure 3 shows that  a
 substantial   reduction (to non-detectable in many areas) in  soil
 concentration was achieved in both the clays and the silty  sands
 within the short treatment period.  The average reduction in  VOC
 concentrations in clay soils where significant contamination  was
 present  was reduced about 977..  Similarly,  in  sands  concentra-
 tions were reduced 897..

      Shallow  soil  gas surveys before, at  mid-point  and  after
 treatment  indicated  consistent  reductions  in  concentrations.
 Figures  4 and 5   shows the dramatic reduction  in  concentrations
 observed by this method.

      Steady  declines  in   extracted  vapor  concentrations   were
 observed  in both  the extraction wells and the  monitoring  wells
 during  the pilot  test.  The wells which weren't affected by   the
 primary  source area showed the greatest reduction in vapor   con-
 centrations  both   in the shallow extraction zone  and   the   deep
 extraction  zone.   In general,  higher extraction rates   were   ob-
 served in the  shallow soils compared to  the deep zone.

       Correlation between  the soil concentration and  the  extracted
 vapor  concentration was  difficult  due to  the  heterogeneities  in
  soil   concentrations at  the beginning of the   treatment  process.
 At   other   sites  where  complete vacuum extraction   systems  are
  implemented,  better correlations have been  achieved.

       Overall    the Terra Vac Vacuum Extraction Process   was  suc-
  cessfully  demonstrated  in  the EPA  SITE  Program.    Cumulative
  extraction of VOC was 1300 pounds as depicted in Figure 6.   As  a
  result  of this successful  demonstration Terra Vac  is   currently
  continuing the cleanup for the owner of the manufacturing facili-
                                  83

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  Vacuum Extraction Technology
  ty on the site.
          Objectives

       Terra Vac has applied Vacuum Extraction Technology at numer"-
  ous   sites  to  achieve various  cleanup   levels.   Since  cleanup
  objectives in  soils are generally site specific,  several examples
  of cleanup objectives and  results of  the  vacuum extraction proc-
  ess achieving  these objectives are presented below.

       Based on  the  data  from the  SITE  demonstration it is estimat-
  ed  that   full  scale cleanup can be achieved to   50  ug/kg using
  vacuum extraction  within about one year of operation.  The clean-
  up objectives  for  TCE in the soils have been designated  by EPA in
  the   ROD at 6.3 ug/kg.  Extrapolating  the level of  cleanup  from
  the   data  from the SITE demonstration,  complete  cleanup  would
  probably occur within about two  years.

       Florida  Department of Environmental Regulacion  (FDER)  has
 defined a excess soil contamination as 500 ppm of hydrocarbons in
 headspace  of  a   sealed container of  soil.   The  concentration
 extracted  from  the wellhead may be  considered  essentially  an
 aggregate "headspace" concentration of hydrocarbons in the  soils
 around  the well screen so that the 500 ppm hydrocarbon  response
 would represent the upper limit of a cleanup goal.  Lower  values
 may be required at certain sites in order to protect   groundwater
 resources.    Application  of the Terra Vac Process at a  site  in
 Florida  demonstrated the capability of the process to   meet  the
 FDER  cleanup objective in about 6 months of operation,   removing
 over 20,000 pounds of hydrocarbons during the process.

      An  alternative  criteria  for considering the cleanup  goal
 would  be  based  on a drinking water standard  for indicator parame-
 ters   and  correlate to  an extracted  vapor   concentration.   For
 example,  the  lowest Maximum Contaminant  Level in Florida  is  1
 ug/1   for benzene.   Goals for cleanup  of  the vadose zone  may  be
 considered   using  the concentration of benzene in  the soil  water
 or pellicular water just above  the water  table and Henry's Law to
 calculate the vapor concentration.

     Based   on  a measured Henry's Law  Constant for benzene,   the
 soil gas concentration in equilibrium  with water at 1 ug/1  would
 be  about   0.18 ug/1  or  0.05 ppm  benzene  in   air.   Assuming  the
 extracted   vapors   from  the wellheads are  sufficiently  close  to
 equilibrium conditions,  an area within  the radius  of- influence of
 the well may be considered clean  if  the concentration of  extract-
 ed benzene vapors is  less than 0.05  ppm.  This  objective  was also
 met  during  the  FDER demonstration after about   six  months  of
 vacuum extraction by  Terra Vac.

     At an industrial site in South Carolina  the same concept was
applied to lower TCE concentrations  in soil to below levels  that
would  impact  groundwater quality.  Terra  Vac  utilized  Vacuum
Extraction Technology with the dual vacuum extraction approach to
                               84

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Vacuum Extraction Technology
clean up soils and groundwater.  Initial soil concentrations were
about  300 ppm and reduced to less than 1 ug/kg.  At less than  1
ug/kg in soil, the TCE would be below drinking water standards in
the  soil water.  Hence, the source of groundwater  contamination
was eliminated by the vacuum extraction process.

     At another Superfund site in Puerto Rico, Vacuum  Extraction
Technology was applied to reduce carbon tetrachloride  concentra-
tions in silty clay soils to less than 10 ug/kg.  Initial concen-
trations were  above 2000 ppm.  The full scale cleanup took about
three  years  of operations to complete,  removing  over  100,000
pounds of VOCs from the subsoils.
Conclusion

     Vacuum   Extraction Technology  has  been   successfully   demon-
strated   in  the EPA SITE  Program  to effectively remove  VOCs from
soils.    Concentrations   of  TCE  in  soil were  reduced  by   897.   in
sands  and   about  967.  in  clays for  the  eight  week  demonstration
period.   Data  from this site and  the  more than  70   sites  where
Terra  Vac has applied this  technology  clearly demonstrates that
the  Vacuum   Extraction Process  can completely  treat  soils  and
groundwater  contaminated  with VOCs.
                                 85

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               Manufacturing Building
            LEGEND
EW- I •   SOIL VAPOR EXTRACTION WELL
MW-5 D   SOIL VAPOR MONITORING WELL
                             86
    TERRA VAC
EPA  SITE DEMONSTRATION

       SITE  PLAN
       FIGURE  NO. I

VACUUM  EXTRACTION TECHNOLOGY

-------
                 TOTAL VOC's vs.  TIME
                           VE1-S
      2500
      2000
00
--4
 1500
PPM
 1000
       500
         0
          0
                   500_ltjr_ ,.     JOOO
                      TIME (hours)
         TERRA VAC VACUUM EXTRACTION TECHNOLOGY
         EPA SITE DEMONSTRATION
                                                       1500
                                             FIGURE  2

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            CLEANUP PERFORMANCE
       TCE CONCENTRATIONS in CLAY and SAND
              Avg Init Cone and Avg Final Cone
     400
CO
                Clay
   MW -3 and EW - 4
                                             Final

                                             Initial
Sand
        TERRA VAC  VACUUM EXTRACTION TECHNOLOGY

              EPA SITE DEMONSTRATION
           FIGURE  3

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PRETREATMENT SHALLOW SOIL- GAS CONCENTRATION
                          89

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6  230 -=
a
a
      0
                                       vnu3
              VMUI2
VMW4
                  POSTTREATMENT  SHALLOW SOIL GAS CONCENTRATION



          TERRA VAC   VACUUM  EXTRACTION  TECHNOLOGY



          EPA   SITE  DEMONSTRATION
            FIGURE   5
                                          90

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    CUMULATIVE POUNDS  EXTRACTED
               Pounds vs Time
  1500
  1000

Lbs

  500
    0
     0
20
40
                                            60
All Extraction Wells
                    DAYS
     TERRA VAC  VACUUM EXTRACTION TECHNOLOGY

     EPA SITE DEMONSTRATION
                     FIGURE 6

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ULTROX
INTEHIMATIONAL
3435 South Anne Street
Santa Ana. California 927O4
TEL: [714] 545-5557
FAX: [714] 557-5336
              UV/OXIDATION OF  ORGANIC CONTAMINANTS

             IN  GROUND,  WASTE, AND LEACHATE WATERS
                         BY:   David B. Fletcher
                              Eriks Leitis
                              Due H.  Nguyen
                      ULTROX INTERNATIONAL
                      2435 S. Anne  Street
                      Santa Ana, CA 92704
                       Presented at the
                 1989 EPA Superfund Symposium

                       Atlanta, Georgia

                         June 19 -  21
                            92

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                        TABLE OF CONTENTS
INTRODUCTION   	'-
DESCRIPTION OF THE UV/OXIDATION PROCESS	2
ULTROX® UV/OXIDATION EQUIPMENT   	2
APPLICATION OF UV/OXIDATION	 .3
CASE STUDY:    EPA SITE PROGRAM - LORENTZ BARREL
               AND DRUM SITE, SAN JOSE, CA   	4
CASE STUDY:    AUTOMOTIVE PARTS MANUFACTURER,
               MICHIGAN	6
UV/OXIDATION TREATMENT AND OPERATING COSTS   	7
SUMMARY     	*7
Table 1   Oxidation of Methylene Chloride & Methanol	9
Table 2   Industrial Effluents Treated with
          UV/Oxidation   	9
Table 3   Groundwaters Treated with UV/Oxidation    	9
Table 4   Treatability and Design Study Results
          Using Pilot Plants On-Site    	  10
Table 5   Full-Scale ULTROX® Systems    	.  ...  11
Table 6   Direct  Operating and Maintenance costs  for
          UV/Oxidation at Industrial Installations    	  12
Table 7   Typical Direct Operating  & Maintenance  Costs
          Using UV/Oxidation for Water  Supplies   	  13
Table 8   Typical Capital Costs  for UV/Oxidation
           Systems  	  	
Figure  1  Isometric View of  System    	15
Figure  2  System  Flow  Diagram	•  16
Figure  3  Ultrox  SITE  Demonstration -  TCE Removal  	  -17
Figure  4  Ultrox  SITE  Demonstration -  DCA Removal	18
Figure  5  Ultrox  SITE  Demonstration -  TCA Removal  .  .  .  .  •  •  18
                               93

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 INTRODUCTION

 The removal of low levels of organic contaminants from groundwaters
 and industrial wastewaters presents a challenge to  environmental
 professionals.   Well-known and commonly used  treatment  processes
 such  as granular activated carbon (GAG)  and air-stripping transfer
 pollutants from one medium to another.  With increasing public and
 regulatory  concern  over  the  final  fate  of  pollutants,   such
 transference technologies are not optimal.

 Conventional chemical  oxidation has been used  in the treatment of
 various waters polluted by organic chemicals for a number  of years.
 Potassium permanganate,  chlorine and chlorine dioxide have  been
 used  for  treating  organics  such as  phenol and  its homologs  in
 wastewaters.   Hydrogen peroxide with a  catalyst such as  ferrous
 sulfate  (Fenton's Reagent) has been used for oxidizing phenol and
 other^ benzene  derivatives.   Processes utilizing  iron  catalyzed
 peroxides and  chlorine   compounds  are attractive   in that  they
 utilize relatively low-cost treatment equipment.  The  disadvantages
 of  these  processes are that they can attack only a limited number
 of  refractory  organics,   and   they  produce  iron  sludges   or
 chlorinated  organics.  Ozone alone has been used to treat phenolic
 wastes, cyanides and certain pesticides.  Ozone treatment  is a  very
 clean process but is limited in the number  of  compounds  which can
 be  treated.    These  oxidation processes have  been  used and  are
 continuing to be used  in  a number of situations.

 The use of ultraviolet  light catalyzed ozone plus hydrogen peroxide
 (UV/oxidation) as a water treatment technique is rapidly expanding.
 It  offers a  means  of solving  many  of the problems created by  the
 toxic water   soluble organic  chemicals that are found  today  in
 groundwater,  wastewater,  leachate  and  drinking water   supplies
 without many of the  disadvantages  of more  conventional treatment
 techniques.

 UV/oxidation, when used as a stand-alone treatment process, or in
 tandem  with   some  of  the above mentioned  processes, can cost-
 effectively destroy or  render non-toxic the organic chemicals found
 on the EPA's  priority pollutant list.

 This  paper describes  the  experience  of Ultrox  International  in
 developing and  applying  the ULTROX® UV/oxidation process to  the
 full-scale treatment of organic chemicals in wastewaters,  drinking
waters, leachates and  groundwaters.   The oxidants used  in these
 applications are ozone  and hydrogen peroxide. Ultrox International
was issued a  process patent in 1988 covering the application of UV
 light, ozone  and hydrogen peroxide to  the treatment of a broad
range of organic compounds in water.
                               94

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DESCRIPTION OP THE UV/OXIDATION PROCESS

The  ULTROX®  process  was  developed  over  a  15  year  period.
Ultraviolet  light,  when combined  with O3 and/or H2O2 produces a
highly oxidative environment significantly more destructive  than
that created with O3 or H2O2 by themselves or in combination.

UV light significantly enhances ozone or H2O2 reactivity by:

    I.
   II,
Transformation of O3 or H2O2 to highly reactive
(OH)" radicals

Excitation of the target organic solute to a higher
energy level
  III.    Initial attack of the target organic by UV light

The importance of the conversion of the ozone or H2O2 to (OH) "can be
more easily understood after studying the relative oxidation power
of oxidizing species.  Hydroxyl radicals  have significantly higher
oxidation power than either hydrogen peroxide or ozone.
       Species

       Fluorine
       Hydroxyl Radical  (OH)
       Atomic Oxygen
       Ozone
       Chlorine Dioxide
       Hydrogen Peroxide
       Perhydroxyl Radicals
       Hypochlorous Acid
       Chlorine
                       Oxidation
                       Potential
                         Volts
                         3.06
                         2.80
                         2.42
                         2.07
                         1.96
                         1.77
                         1.70
                         1.49
                         1.36
Relative
Oxidation
 Power*

  2.25
  2.05
  1.78
  1.52
  1,
  1,
 ,44
 ,30
1.25
1.10
1.00
          * based on chlorine as reference  (=  1.00)

The effect of UV enhanced oxidation  is illustrated  in  Table  1.

ULTROX® UV/OXIDATION EQUIPMENT

ULTROX® UV/oxidation  equipment  treatment systems:   (1) have very
few  moving parts,  (2)  operate  at  low  pressure,  (3)  require  a
minimum of maintenance,  (4)  operate full-time or intermittently in
either a continuous or batch treatment mode, (5) utilize efficient,
low temperature, long  life UV lamps, and (6) can employ the use of
a micro-processor to control and automate the  treatment process.

The ULTROX® UV/oxidation system consists of a UV/oxidation reactor
and an oxidation  source —  either an ozone generator with an air
preparation system and/or a  hydrogen peroxide feed system.   Figures
                                95

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 1 and 2 show an isometric assembly view and drawing of a Model F-
 650 system,  which accommodates flow rates up to 60 gpm or batches
 of 650 gallons.

 The reactor  is fabricated from stainless steel.  The UV lamps are
 enclosed within quartz tubes for easy replacement and are mounted
 vertically within the  reactor.  Depending upon size of the reactor
 and the type of water to be treated, the reactor  can have 4  to 8
 stages.   Lamps are installed either in all stages or in designated
 stages,   depending  upon the type  of treatment specified.   When
 ozone is used as the oxidant,  it is introduced at the base of the
 stage.    The ozone  is dispersed through  porous  stainless steel
 diffusers.   The number  of  diffusers needed will  depend  upon the
 type of organics being oxidized and the degree of removal required.

 Ozone< is produced from either compressed  air,  dried to  a -60°F
 dewpoint by  desiccant  columns,  or produced  from cryogenic oxygen.
 Up to 2% wt. ozone is  generated from air, and up  to  5% wt. ozone
 can be produced economically from oxygen.

 When hydrogen  peroxide  is used  in the process,  it is  directly
 metered  into the influent line  to the reactor.

 Within_ the  reactor, the water flows from  stage to  stage in  a
 sinusoidal path using  gravity flow.   When the  reactor uses ozone,
 the residual ozone in  the off-gas is  decomposed  back  to oxygen  by
 the use of a fixed-bed catalytic unit operating at 150°F.   The air
 is then vented to  the  atmosphere.

 Ozone generators with  varying capacities are used with the Model
 F-650 reactor.  The size of generator depends upon the ozone dosage
 requirements.   Present  installations use  28 to  140  Ib.  per  day
 capacities.

 APPLICATION  OP UV/OXIDATION

 UV/oxidation equipment developed by Ultrox in recent years  has been
 used to treat a wide  variety of  waste streams.  Tables 2 and 3 list
 toxic compounds found  in groundwaters and  wastewaters that have
 been successfully  treated with the  ULTROX® UV/oxidation  System.
 Specific  case histories  of  treatability and  design  studies  for
 private  industries and  military  installations  are  presented in
 Table 4.   In  each of   these  cases,  pilot  treatment  plants were
 operated on site to develop treatment design and economic data.

 Contaminates oxidized  included:  pesticides, petroleum compounds,
munitions, and  chlorinated solvents.

Table  5  illustrates  projects where the treatability  and design
studies  were   converted  into   permanent  on-site  UV-oxidation
installations.    The  systems  to  date  treat  either  industrial
groundwaters,  wastewaters and  process waters.    Contaminants  in
                               96

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these waters  include phenols,  chlorinated  solvents,  hydrazine,
dimethylnitrosamine, tetrahydrofuran and formaldehyde.  Commercial
systems have  been designed, built  and installed to  treat flows
varying from 10,000 gallons to 300,000 gallons per day.  A system
to treat 1.3 million gallons per day is under construction.

Standard equipment designs are  used  in  all of these installations.
Reactor size  varies from  300  gallons  to  4,300 gallons.   Ozone
generators range from 21 Ib. to 140 Ib per day.  In several cases
hydrogen peroxide is used in place of or with ozone.

Treatability studies are carried out first in the laboratory using
glassware equipment  to  determine  the feasibility of treating the
water with UV/O3,  UV/H2O2, or UV/O3/H2O2.

If the results are encouraging, the next step in the study involves
the installation of a skid-mounted pilot plant on site.  Sufficient
design and  economic data normally are  collected  within 2 weeks.
Specifications  for  the  full-scale  system are  then prepared.
Standard  reactors,  ozone  generators and hydrogen  peroxide feed
systems are utilized.    Systems  are assembled  and  tested at our
facilities and then shipped to the job site.  The systems are then
installed,  checked  out, and turned  over to the  customer.   Full
service maintenance  contracts are available.

Full-scale   systems,   in   most  cases,   are   automated  using
microprocessor  control.   The  system  usually  requires periodic
monitoring  (once per shift or once per  day).   The  systems are
designed  to  operate in  a batch or continuous mode depending upon
treatment requirements.

In a number of cases, UV-oxidation is used as a part of a treatment
train.    For  example,   at  wood treating sites prior  to  the UV-
oxidation  treatment,   the  wastewater or   groundwater  requires
breaking  of oil/water  emulsions and removal of suspended matter,
as well as  adjustment of pH.
 CASE  STUDY:
EPA SITE PROGRAM - LORENTZ BARREL AND DRUM SITE,
SAN JOSE, CA
 The  EPA  has  established  a  formal  program  to  accelerate  the
 development,   demonstration,  and  use   of  new  or   innovative
 technologies to be used in site cleanups.  This program, called the
 Superfund Innovative Technology Evaluation (SITE) program, has four
 goals:

      •    To  identify and, where possible, remove impediments to
          the   development  and   commercial  use  of  alternative
          technologies.

      e    To conduct  a demonstration program of the more promising
          innovative  technologies for the purpose of establishing
                                97

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           reliable  performance  and  cost  information  for
           characterization and cleanup decision-making.
site
      •    To  develop  procedures  and  policies  that  encourage
           selection of available alternative treatment remedies at
           Superfund sites.

      •    To structure a development program that nurtures emerging
           technologies.

 Each  year,   EPA  solicits proposals  to  demonstrate  innovative
 technologies.   To identify the best available technologies,  an
 extensive solicitation is necessary.   A  screening  and  selection
 process follows,  based on  four factors:    (1) the technology's
 capability  to  treat  Superfund  wastes,  (2)   the  technology's
 performance and cost expectations,  (3)  the technology's  readiness
 and  applicability  to full-scale  demonstrations,  and  (4)  the
 developer's capability and approach to testing.

 In the third   year of the  SITE program, Ultrox was selected  to
 demonstrate their UV/oxidation technology.  The Lorentz Barrel and
 Drum Superfund site in San Jose, California  was selected  for the
 demonstration.

 The Lorentz  site was used for  drum  recycling for nearly  40 years.
 Over this period  of time,  the site received drums  from over 800
 private companies,  military  bases,  research  laboratories,  and
 county agencies in California and  Nevada.   Drums arrived  at the
 site containing residual  aqueous wastes,  organic solvents,  acids,
 metal oxides,  and oils.

 Since 1968,  there have been  several regulatory  actions  at the
 Lorentz site.   In 1987, the Lorentz facility ceased  operation and
 the  EPA<  assumed  lead   agency responsibility  for  the   site
 remediation.  Investigations revealed that the groundwater  beneath
 the site  was contaminated with a number  of  chlorinated solvents,
 chlordane, toxaphene and PCBs.

 An^ULTROX® P-150 pilot plant was moved  in on February 21,  1989.
 Thirteen  (13)  tests were  conducted  between February 24 and  March
 9,  1989,   on  extracted groundwater from the site.    During the
 treatability  bench  studies,  TCE,  TCA,  and  DCA were chosen to
 monitor the progress of the pilot.

 Figures 3, 4 and 5 illustrate analyses of the waste  stream'influent
 and the treated effluent for the targeted contaminants.

 The  final  report has not  yet  been  issued by the  EPA.   However,
 based on the preliminary results,  the ULTROX®  UV/oxidation process
was successful in  the reduction of  all of the VOCs present in the
 groundwater at the Lorentz site to below drinking water standards.
                               98

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The bicarbonate level of the groundwater was extremely high (1200
mg/1).  Because of this, treatment costs are higher than what would
be experienced in more normal groundwater applications.  Based on
the conditions tested at the site, treatment .costs were estimated
to be as follows:
     Flow Rate:
     Influent Concentration:

     Effluent Concentration:

     Treatment Costs:

          Ozone  (@ 0.06/KWH)
          H202  (@ $0.75/lb)
          UV (incl. power
            and  annual lamp
            replacement
100 gpm
250-1000 MgA VOCs,
  pesticides, PCBs
    Mg/1
$/1000 gallons

$ 0.370
  0.156
  0.836
          O & M Cost            1..36
          Capital Amortization
            (16%/year)          0.75
     Total Treatment Cost:    $ 2.11/1000 gallons
CASE STUDY:   AUTOMOTIVE PARTS MANUFACTURER, MICHIGAN

Testing of water beneath a Michigan automotive parts manufacturer
revealed  significant  VOC contamination.  TCE  levels  of 5,000 to
10,000  Mg/1  were  recorded  as  well  as  trace  levels  of other
chlorinated solvents.   The Michigan Department of Natural Resources
required  that the manufacturer pump and -treat the groundwater.

The  manufacturer  investigated  air  stripping  with GAG  off-gas
treatment, aqueous phase GAG and ULTROX® UV/oxidation as possible
treatment alternatives.  Bench scale studies were conducted at a
GAG  supplier and  at  Ultrox's  laboratory.   While  all treatment
techniques could provide the required removal levels, UV/oxidation
was  the  most economical.  An  ULTROX®  P-75  pilot scale treatment
system was delivered  to the site.  Testing over  a two week period
confirmed the data obtained in the laboratory.   An ULTROX® F-3900
treatment system was  ordered  and installed  in May,  1989.   The
system is currently operating and achieving the  following results,
which exceed Michigan requirements:
     Flow Rate:
     Influent Concentration:
     Effluent Concentration:
210 gpm
5500 Mg/1 TCE
1 Mg/1 TCE
                                99

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      Treatment Costs:

           Ozone (@ 0.06/KWH)
           H202  (@ $0.75/lb)
           UV (incl. power
             and annual lamp
             replacement
$71000 gallons

$ 0.119
  0.188
           O & M Cost            0.44
           Capital Amortization
             (16%/year)           0.29
      Total Treatment Cost:     $ 0.73/1000 gallons

 UV/OXIDATION TREATMENT AND OPERATING COSTS

 Table 6 represents the direct operating and maintenance costs for
 treatment of contaminants in groundwater  at water  utility sites.
 The costs are  based upon pilot plant  studies at  four  different
 sites  in  Southern  California.     At   three  of  the   sites,
 perchloroethylene  (PCE)  and  trichloroethylene  (TCE)   were  the
 contaminants  with concentrations ranging from 20 ppb to 200 ppb.

 Table 7  presents the  actual  costs of  treating by UV/oxidation
 wastewater and  groundwaters  at   various  permanent   industrial
 installations.   Some of these costs are in the cents per thousand
 gallon range  and others in  cents per gallon range.

 In  the case of  the hydrazines,  a small  volume  of  water  is  treated
 per day on a batch basis and a comparatively long reaction  time is
 needed.    UV/oxidation was found  to be  the most  cost-effective
 method of destroying  the three   types  of  hydrazines and  the
 nitrosamine which is formed as a by-product by the oxidation.   The
 UV/oxidation  system replaced  a chlorination unit, which produced
 chlorinated organic by-products.

 The price  range of UV/oxidation equipment at various installations
 cited in  Table  8 varies  from $45,000  to $300,000  (uninstalled).
 Pricing depends upon the oxidant  requirement  - whether ozone  or
 hydrogen  peroxide is used,  the chemical structure of the  organic
 compounds  treated,  the number  of  UV  lamps  required, and  the
 retention  time   required  to  achieve  an  acceptable  discharge
 standard.

 SUMMARY

 Over  the last 15  years, UV/oxidation has progressed from research
 and development  to  commercial operation.   During these  years,
Ultrox has advanced its design through applied bench testing, pilot
studies,^ and  full-scale systems that remove contaminants  from a
wide variety of wastewaters and groundwaters.
                               100

-------
UV/oxidation  technology  is  not   suitable  for  every  organic
contamination problem.  It can, however, effectively address a wide
range of clean-up needs.   This form of on-site chemical oxidation
can offer real advantages over  conventional treatment techniques
and  should   be   considered  when  evaluating  water  treatment
alternatives.
                               101

-------
 TIME
 fMIN.l

  0
 15
 25
                              TABLE 1

                 OXIDATION OF METHYLENE CHLORIDE
CONTROL

  100
  100
  100
UV
UV/H202
100    100
 59     46
 42     17
O-3/H2°2    UV/O3
            100
             32
             21
           100
            36-
            16
     100
      19
     7.6
 TIME
 (MIN.)

   0
  30
  CONTROL

     75
     75
                      OXIDATION OF METHANOL
CONCENTRATIONS = mg/1
     UV

     75
     75
       UV/H202

          75
          75
         UV/0,

          75
          31
UV/03/H202
   75
  1.2
                             TABLE  2
Industrial effluents containing:

      Amines
      Analine
      Benzene
      Chlorinated  Solvents
      Chlorobenzene
      Complex Cyanides
      Creosote
      Hydrazine Compounds
      Isopropanol
      MEK
      MIBK
                        Methylene Chloride
                        PCB' s
                        Pentachlorophenols
                        Pesticides
                        Phenol
                        RDX
                       -TNT
                        Toluene
                        Xylene
                        Polynitrophenols
                             TABLE 3
Groundwaters containing:

      BTX
      Creosote
      1,2 DCA
      DCEE
      Dioxins
      Dioxanes
      Freon 113
      MeCl2
      MIBK
      PCBs
                        PCE
                        Pentachlorophenol
                        bis  (2-chloroethyl)  ether
                        Pesticides
                        Polynuclear Aromatics
                        1,1,1 TCA
                        TCE
                        THF
                        Vinyl Chloride
                        Triglycol dichloride ether
                                102

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                                               TABLE 4

                   TREATABILITY AND DESIGN STUDY  RESULTS USING PILOT PLANTS ON SITE
o
CO
     Customer

     Bulk Chemical
     Transfer Depot

     Municipal Water
     Producers

     Aerospace Co.
Chemical Co.


Automotive Co.

Electronics Co.



Munition Plants


Army Bases
     Petrochemical
     Mfr.

     Semiconductor
     Mfr.
Application

Contaminated
groundwater

Contaminated drinking
water supply

Paint stripping
wastewater

Wastewater
Groundwater

Wastewater/runoff
water, groundwater
                        Wastewater
                        Contaminated
                        groundwater
     Semiconductor Co.  Wastewater
                   Wastewater
                   Groundwater
                                          Contaminants

                                          TCE,  PCE,  methylene
                                          chloride

                                          TCE, PCE, color
                                          Methylene chloride
Misc. pesticides
(including DBCP)

TCE, MeCl2

PCBs, ViCl, DCA
+ other VOCs
                      TNT, RDX
                      DIMP, DBCD, VOCs
                                          EDTA
                      Benzene
                      benzene, toluene,
                      xylene, ethyl benzene
Results

Water treated and.
reinjected into ground

VOCs and color reduced to
below state action levels

MeCl2 reduced from 4000 ppm
to less than 100  ppb

DBCP and other pesticides
reduced to less than 1 ppb

Reduced 10 ppm to 5.0 ppb

Reduced PCBs to less than
1 ppb; VOCs reduced to
below state action levels

TNT & RDX reduced from
100 ppm to less than 1 ppm

DIMP & DBCD reduced to
less than 10 ppb; VOCs
reduced to below state
action levels

Reduced EDTA from 6,000
ppm to 100 ppm (acceptable
discharge standard)

Reduced benzene from 10 ppm
50 ppb

Reduced contaminants from
14.0 ppm to 4.0 ppb

-------
                                          TABLE 5

                                FULL-SCALE ULTROX® SYSTEMS
Customer

Wood Treating
Plants (2)

Closed Wood
Treating Plant

Chemical Plant
Automotive
Foundry

Aerospace Co.
Chemical Plant
Semiconductor Co.
Application

Wood treating
wastewater

Contaminated
groundwater

Fume scrubbing
water
Contaminated
groundwater

Contaminated
groundwater

Wastewater
Contaminated
groundwater
Contaminants

Phenol, pentachloro-
phenol

Phenol, pentachloro-
phenol

Hydra z ine, monomethy1
hydrazine, unsym-
metrical dimethyl
hydrazine
TCE, Trans 1,2-DCE
TCE, TCA, DCA, PCE
MeCl2,  vinyl chloride

Phenol, formaldehyde
THF
Results

Water treated and
discharged to POTW

Water treated and
discharged to POTW

Destroyed parent
compounds to N.D.
levels and dimethyl
nitrosamine below
10 ppb

Water treated and
discharged to lake

Water treated and
discharged to POTW

Water treated and
discharged to POTW

Replaced a GAG system to
reduce THF from 1,000 ppb
to less than 5 ppb

-------
                                             TABLE  6

                           TYPICAL DIRECT OPERATING & MAINTENANCE COSTS

                              USING UV-OXIDATION FOR WATER SUPPLIES*
o
en
Type of
Water

Contaminated
potable drinking
groundwater

Contaminated
potable drinking
groundwater

Contaminated
potable drinking
groundwater
                        Contaminants


                        TCE,  PCE
                Total Contaminant
                  Concentration
Treatment
Standards
TCE, PCE        200 ppb
                        Color
                                                                               Direct 0 &. M
                                                                               Cost Range
                                                                               rS/1000
                less than 20 ppb   Drinking Water     0.10 to 0.20
                                                           Drinking Water     0.20 to 0.30
                70 color units     Drinking Water     0.10 to 0.15
            *  Assumes cost of electrical energy is $0.06/KWH

-------
                                         TABLE 7
                 DIRECT OPERATING & MAINTENANCE COSTS FOR UV-OXIDATION
                               AT INDUSTRIAL INSTALLATIONS
Type of Water  Contaminants
Wood Treating
Wastewater
Wood Treating
Groundwater
Fume Scrubber
Water
Contaminated
Groundwater

Contaminated
Groundwater

Contaminated
Groundwater
Pentachloro-
phenol and
phenol

Pentachloro-
phenol and
phenol

Hydrazene,
Monomethyl-
hydrazine
Unsymmetrical-
dimethyl-
hydrazine

TCE, trans DCE
MeCl2

TCE, TCA, DCA,
PCE, MeCl2 ViCl

THF
                                            Volume
                  Contaminant   Discharge   Treated  Direct O & M
                                    to
Con centrat i on

  150 ppm      POTW
    5 ppm
5,000 ppm
    5 ppm


  600 ppb


    1 ppm
POTW
Biotreat-   600 -
ment Plant  1500
On-Site
Per Day   Cost Range	

30,000   $1.25-1.35/1000 gal



86,400   $0.90-$1.00/1000 gal



         $0.086/gal
Surface    300,000   $0.47/1000 gal
Water

POTW        72,000   $0.33/1000 gal


Ground     216,000   $0.39/1000 gal
Wastewater
Phenol
   90 ppm
POTW
 4,:300   $6.48/1000 gal

-------
                                        TABLE 8


                    TYPICAL CAPITAL COSTS FOR UV-OXIDATION SYSTEMS
Type of Water
Wood Treating
Wastewater
Wood Treating
Groundwater
Fume
Scrubber
Water

Contaminated
Groundwater

Contaminated
Groundwater
Contaminated
Groundwater

Wastewater
Contaminants
Pentachloro-
phenol
Phenol

Pentachloro-
phenol
Phenol

Hydrazines
TCE, trans DCE
MeCl2

TCE, TCA, DCA
PCE, MeCl,,
ViCl

THF
Phenol
    Total
 Contaminant
Concentration
   150 ppm



     5 ppm



 5,000 ppm



     5 ppm


   600 ppb



     1 ppm


    90 ppm
 Water
 Flow      Price Range
 Rate      - funinstalled)
 (GPD)           $

  30,000   125,000-150,000
  86,400   175,000-200,000
600-1500   125,000-150,000
 300,000   225,000-275,000
  72,000   130,000-150,000
 216,000   250,000-300,000
   4,300    45,000-55,000

-------
                                               Cu
CotuS/Bc QxcfM D«cs
-------
               Rutomiuf
                topical)
HeedtaVoh*
 tow)
                                                             FramShafln
                                                             Daund-WaUr
                                                                    Vtb
                                                                                       Diluent
                                                                                 FIGURE  2

                                                                               ULTROX SYSTEM
                                                                                FLOW DIAGRAM
                                                                         B&Altfl; it/yes IHEVBB; 02/02/93 | PiOtJ3ff
Hntogoa
  FMTonk
                                               16

-------
             FIGURE 3
ULTROX SITE DEMONSTRATION
        TCE REMOVAL
                          INF.
       B
            TEST NUMBER

-------
                 FIGURE 4
     ULTROX SITE DEMONSTRATION
            TCA REMOVAL
               TEST NUMBER
                 FTflllRH 5
 ULTROX SITE DEMONSTRATION
          DC A REMOVAL
.5
                TEST.NUMBER

-------
                  In Situ Steam/Air  Stripping
               Phillip La Mori  and Jeff  Guenther
                  Toxic Treatments (USA)  Inc.


      Toxic Treatments is currently remediating  a site  in San
 Pedro, California, using technology  developed and patented by
 Frank Manchak  (U.S. Patent No.  4,776,409.)   This process removes
 volatile organic compounds (VOC's) from  contaminated soils by
 injection of steam and air.

      The steam and air are injected  into  the  ground by means of a
 pair  of hollow kelly bars.  The kellys distribute the  air and
 steam within the soil through rotating mixing blades five feet in
 diameter.  The volatiles are evaporated  from  the soil  matrix,
 into  the remediation air.  Effluent  gases move  up beside the
 drilling shafts to the surface, where they are  collected in a
 metal shroud.

      The shroud runs under a slight  vacuum.   A  blower  mounted on
 a  separate process chassis extracts  the air and vapors,  along
 with  a small amount of dust,  from the shroud  and directs them to
 a  process train where contaminants are removed  and collected for
 recycling or disposal.   The treated  air is recompressed and
 reinjected into the soil.

      The shroud effluent gas  is analyzed continuously  during
 remediation.   Instruments on  board the process  train include a
 gas chromatograph, two  flame  ionization detectors, and pressure,
 temperature,  and humidity measuring  equipment.

      The apparatus is moved around the site by  a  heavily modified
 Caterpillar 583 pipe layer.   The drill stems will  reach  more than
 thirty feet below the surface.   Drilling rates  of  3 feet per
 minute are possible,  depending on the nature of  the soil and
 contaminant type and concentration.

      The San Pedro site  must  be remediated to remove residual
 VOC's, including chlorinated  compounds.   There are also  semi-
 volatile hydrocarbons (SVH's)  in this soil.  These SVH's do  not
 present much,  if any, environmental  hazard because their
 migration rate is negligible.   You wouldn't want to eat  this
 soil,  but the  SVH's  do not evaporate  and were not expected  to  be
 significantly  affected by the  remediation process because  of
 their low vapor pressures.

     Initial VOC  concentrations were  between 824 and 1872 ppm.
The target  remediation level was 100  ppm of VOC's.

     Test results  to  date  show  that the  VOC's are effectively
remediated.  The  range of  reduction of VOC's is from 96  to 99
percent,  using  EPA 8240 analysis methods.   There are about  15
volatile  compounds in this soil.  We  were able to reduce their
total  concentration to less than 55 ppm,  well below the  target
level  of  100 ppm.

    Silty soils  remediate more  easily than clay.  Moist clay
                                 112

-------
soils containing tetrachloroethylen  were also remediated by
better than 95 percent,  but the final levels were 53 to 203 ppm,
somewhat higher than target levels.  This may be adequate, but
changes have been made in the process which improved the absolute
remediation level..

     The process also removed most of the semivolatiles as listed
in EPA 8270.  This was somewhat unexpected and we have spent
considerable time trying to determine the mechanism for their
removal.  About 85 percent of the SVC's found on the site are
phthalate esters of various aliphatic radicals, e.g., ethylhexyl
phthalate.  We believe that these esters are being hydrolyzed to
an intermediate acid salt and an alcohol.  The alcohol appears to
dehydrate to an olefin.  Soil and recovered fluid analyses
support these ideas.  Some SVC's like isophorone and phenol may
be quantitatively removed by steam distillation or vaporization.

     The recovered VOC's represent most of the starting
calculated mass.  Field monitoring of gases outside the shroud
and analyses of adjacent blocks show little or no escape  of VOC's
to the surroundings.  We believe that the process is very
effective for volatile materials.  The process also is somewhat
effective for semi-volatiles, but  this depends on the  species
present.

     Treatment  rates vary depending  on the amount of contaminants
and  type of soil, as  indicated  above, but  the  average  is  about 6
to 8 cubic  yards per hour.

     The Detoxifier  (tra) apparatus may also be used  for  other
types  of  in situ  treatment,  including the  addition  of  soil
stabilizers,  injection  of  reagents,  or for bioremediation.   Two
more complete  drilling  units have  been assembled, and  process
trains for  those  units  will  be  designed  to match the needs of
particular  applications.
                                   113

-------
 AVERAGE VOC CONCENTRATION
               (ppm)
         Area
          A

          B

          D
Be fora
 1,114

 1,353

 3,954
After

  12

  30

 139
AVERAGE SVH CONCENTRATION
              (ppm)

        Area  Before  After
         A    3,775   627

         B   12,116  1,766

         D    1,014   85
                                  VOC CONCENTRATIONS (ppm)
Block
A-8-Q
A-9-g
A- 10-g
B-50-n
B-61-n
B-61-m
B-62-m
D-92-b
0-03 -b
D-94-b
Balflifl
1,149
824
1,368
1,123
1,500
1.872
917
2.305
3.720
6.838
Attar
 18
 7
 11

 23
 13
 65
 29

 63
163
203
98
99
99

98
99
97
97

98
96
97
                                 SVH CONCENTRATIONS (ppm)
Block
A-8-g
A-9-g
A- 10-g
B-60-n
B-61-n
B-61-m
B-62-m
D-U2-b
D-90-b
D-94-b
Batata
1,794
2.510
7,020
22.829
14.924
10,040
669
707
1,486
869
                                                  Aftec
                                                  637
                                                  863
                                                  592

                                                  1.670
                                                  2,304
                                                  2,496
                                                  694

                                                  55
                                                  90
                                                  111
                                                   64
                                                   74
                                                   92

                                                   63
                                                   86
                                                   76
                                                   11

                                                   92
                                                   94
                                                  87

-------
FATE  OF  SEMI VOLATILE  COMPOUNDS
             phthalate salts  +  C8 to CIS olefins



                               - H20



             phthalate salts  +  C8 to CIS alcohols
 1032 Ibs.  of bis-2-ethylhexyl phthalate
 produce 296 Iba. of ~ "
       VOC MASS  BALANCE
 JrflHtment Slocks
   Pflmealated


     6


     10
 Pounds    Bounds   * voc
Recovered   Removed  Recovered
 124.5


 264.8
142.5


296.6
87.4


89.3
                                        FATE OF SEMI-VOLATILE COMPOUNDS
                                                 Pretreatment  Psrcent   Recovered  Percent
Amount (Ibs)
bls-2-ethylhexyi
phthalate
butyl
cellosolve
Isophorone
2 ethylhexyl
adlpate
phthalate matrix
glycol ethers
C8-C15 HC
others
Total

424.4 38
13.1 1
3.8 <1
2.0 <1
607.8 55
11.8 1
34.1 3
7.5 <1
1104.5 100 t
10 Block
Amount (ibsl*
0
9
28
0
0
<1
393
42
473
Total
0
2
6
0
'•"" 0
0
83
9
100
Project
                                         THC CONCENTRATIONS (ppm)
Slock
A-8-0
A-9-g
A-10-g
B-6O-n
B-51-n
B-51-m
8-52 -m
D-92-b
D-93-b
D-94-b
Befors
2,943
3.334
8,388
23.952
16,424
11,912
1,686
3,012
5.184
6,707
After
655
660
603
1.693
2,317
2,550
623
108
253
3',4
% Reduction
78
80
93
93 .
86
79
61
96
95
95

-------
        THE PIEPHO CORPQRATTOTXT	
        9341 Cornwell Fanu Rd. Great Palls, Va. 22066, (703) 759-7074
                              INTRODUCTION
      fn        AbwassefTtechnik  GMBH has  been in the waste water
 treatment  business  in  West  Germany for ten years.  We are located in
 Bredenbeck,  a  small  village just  outside of the city of  Hannover
 Over  the years, our  customers have ranged in size  from extremely'
 large concerns, such as  the German Navy  and VW to  small,  single
 factory furniture and  textile companies.  Our latest project  is

                                            landfi11 for the government
 Our firm is relatively small. We only have about  25  employees

 RheineBrauTr *" J^S *?* ***** "* h*™ dev^°Ped a partnership with
 Rhexn Braun, one of the largest energy firms in Germany. This
 partnership, called Union Piepho, gives us the facilities and
 resources to handle jobs of any size. We have also developed partners
 in a number of other countries including Italy, Denmark, India, and
 the United States.
                          PROCESS DESCRIPTION


 We have developed a chemical-physical process for the treatment of
 waste water.  This process consists of Reaction Separation Agents NT75
 and Piepho treatment machines.

 Reaction Separation Agent NT75                                  ,

 NT75 is a separating reactant on a clay basis which by virtue of its
 extraordinarily high effectiveness can crack emulsions,  adsorb
 contaminants,  flocculate and finally encapsulate,  all in one process
 stage.^Furthermore,  once the contaminants have been encapsulated  the
 resulting sludge will no longer  leach.  Due to this characteristic,  we
 have been able  to dispose of much of our sludge on standard household
 dumps,  thus reducing the total treatment costs dramatically.

 The  clays  in Reaction Separation Agent  NT 75 are minerals with an
 expandable triple layer  arrangement  and a cation exchange capacity  of
 80 -  100 m/lOOg.  The  grain size  distribution ranges  from 0.5 - 1.5.
The  use of bentonite  as  the  main flocculant  is unusual because the
particles are too small  to give  good adsorption. On  the  other hand
the  negative charge  on its surface causes it to  be attracted to
cationic positive polymers.  When the polymers  have bonded all oil
molecules the polymer oil complexes  created  become positively charged
and coated by particles  of clay.  The bentonite then  exchanges ions
for polymer oil complexes.
                                     116

-------
      THE PIEPHO CORPORATION
      9341 Cornwell Farm Rd. Great Falls, Va. 22066, (703) 759-7074
The release of clay particles from this bond is virtually excluded. A
polymer oil complex coated by clay particles is practically cocooned
- it is fixed and the reverse reaction or breakdown  is not possible,
even if the pH value changes, thus giving us our stable sludge. Also,
the stabilization and encapsulization process of the sludge doesn't
stop but continues even after dumping and as such  increases the
resistivity to leaching.

One must bear in mind that the interaction between polymers and clay
particles starts immediately after input of the additive  into  the
waste water, and continues during the adsorption process. The
slightly reduced effectiveness of the polymers is  balanced by  an
increase in flocculaton, typical for clay additives.

This possibility, to control polymer oil complexes at the point of
their reaction and formation, is created by combining all chemicals
required in the water treatment into one formula.  The prerequisite
for this is to prepare  (isolate) those components  capable of  changing
the pH value such that  they become effective at the  right point in
time and in the right sequence - so raising or lowering  the pH value.

The use of specially treated organic acids and alkalis with different
solubilities allows the pH value to be controlled  and determined
throughout the process.

A condition of the treatment with reaction separation agent NT75  is
that the fine-grain powdered product is well mixed into  the waste
water. During this mixing process the polymers are distributed,  the
acids  and  alkalis dissolve, polymer oil complexes  are formed  - which
are immediately  cocooned by  the clay particles and so encapsulated.
This process is  repeated continuously during  the  reaction until  all
oil and other contaminants are  fixed. The  mixing  may then be
terminated and conventional  sedimentation  and  drying of  the  sludge
follows. The  time period required in  the  treatment module of  the
plant  depends on the waste water  -  but  it  is  usually about  5  minutes;
the same applies  to  the sedimentation phase.

Piepho Wastewater Treatment  Machines

The Piepho treatment machines  perform  5  basic  functions.

         1)  Automatic  addition  of  Reaction Separation Agent NT75
         2)  High  speed  mixing of the NT75  into the waste water
         3)  Sedimentation
         4)  Filtration
         5)  Drying,removal  of the  sludge
                                     117

-------
       THE PIEPHO CORPORATION
       9341 Comwell Farm Rd. Great Falls, Va. 22066, (703) 759-7074
 The machines have been  designed  to  be  fully automatic,  but  can also
 be run manually. Many of  our machines  process  in  batches, while
 ?romrJo£a?/£1Ja%n°nnin?^Sly* ***  capacities  of  the  machines  range
 from 400 1/h to 30,000  1/h, and  because  they are  fully  automatic,
 they can be run in excess of 20  hours  a  day, thus  allowing  our
 largest machine to clean  600,000 liters  in  a single day. Also   the
 machines have been designed to fit  into  containers which al?ow for
 easy transportation and single' day  setup
           TYPE OF CONTAMINANTS TREATED BY THE PIEPHO  SYSTEM


 In the past, using the Piepho process and other processes which can
 be integrated into our system (reverse osmosis, biological treatment,
 etc.), we have been able to handle all pollutants we  have come 'across
 in water. The Piepho process itself is most effective at removing
 water-insoluble pollutants, both organic and inorganic. It has ^
 been effective at removing a variety of dissolved organics and :
 inorganics (through the addition of both our patented reaction •
 separation agent NT 75 and active carbon),  and heavy metals.

 In Europe, we h'ave concentrated on the handling of industrial waste
 water, polluted groundwater,  and landfill leachate.  Most frequently,
 these applications lead us to a waste water contaminated with oil
 bearing emulsions,  chlorinated hydrocarbons,  heavy metals,  and paint
 remainders.

 We  feel that our system has the  capacity to clean any waste water.
 Whether or not our process is economically  efficient in its treatment
 of  a  specific waste water  must be tested in our  laboratory.  For some
 industrial firms who generate small quantities  of very complicated
 waste  water,  it may still  be  more cost efficient to  have their water
 hauled away to a large waste  water treatment  plant.
                              •
         QUALITY OF EFFLUENT ACHIEVED  WITH  THE  PIEPHO SYSTEM


Our process is very flexible with respect to  the  achievement of
desired clean-up levels. The quality of  the treated  water  can be
increased through the addition of chemicals,  or through  the  choice  of
processes to be used in the treatment  system. The  best way of
illustrating this is with examples.
                                     118

-------
      THE PIEPHO CORPORATION
      9341 Cornwall Farm Rd. Great Falls, Va. 22066, (703) 759-7074
Example 1
     For the continuous circulating process water  in the -finishing
industry, it only makes sense to clean the water to the level where
it meets the quality demands for its continued use. In cases such as
these, single stage systems are usually all that is necessary.

Example 2
     If the treated waste water will be removed to a community
biological treatment plant, then it must only be cleaned  to  the  level
of the inlet values for the plant. In most cases,  this can also  be
handled by a single stage process.

Example 3                                                     .
     If higher quality is needed, for example, if  the water  will be
discharged directly into surface waters, or if total quality levels
or single parameters correspond to those of drinking water,  our
process can also be used to meet these demands. The cost  would
increase  (depending, of course, on the quality of  the waste  water
before treatment), and many stages may be needed,  including:

Pretreatment
      (1) Prescreening to remove suspended solids
      (2) Pretreatment to remove lower density materials  (If  the  water
         contains more than 2% oil,fats,etc.,  this pretreatment  will
         make the next stages more efficient)
Piepho Treatment
      (1) First stage -.addition of NT 75, a  fatty  acid,  bentonite
                       based coagulent/flocculent.
      (2)  Second stage - addition of  active  carbon
      (3) Third stage - addition of Fuller's  earth  mixture
      (4)  Fourth stage - removal of 2,3  above  by NT 75
Further  treatment
      If  necessary,  further  stages  can be  integrated  into the Piepho
      system. These  would include extra  filters, reverse  osmosis,
      membrane filtration,  etc.

To  this  date, we have been able  to meet  all  quality  demands  that have
confronted  us.
                      LIMITATIONS OF THE PROCESS


 The  limitations of our process are accounted for by our pretreatment
 stages.  Our process is not effective if the water contains solids and
 coarse  materials.  Therefore,  these must be removed as much as is
 mechanically possible in the pretreatment. Also, it is not economical
                                      119

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                  ' CORPORATION
       9341 Comwell Farm Ed. Great Falls, Va. 22066, (703) 759-7074
 to use NT75 to treat low density material, such as  oil and grease
 Because of this, we have developed our own pretreatment'to re-over
 these materials. Our process is especially good at  dealing with high
 concentrations of contaminants. However, if the concentrations are
 too nigh (above 2%), then the water must be diluted. The limitation
 here is mechanical. The machines are not designed to handle large
 amounts of sludge. Mr. Piepho's suggestion in cases where the
 concentration is too high is to use the water which has already been
 treated to dilute the remaining waste water. In this way only a
 minimal amount of fresh water must be used.
                                 COST                           i


 General  statements about the economic side of our process are  '••
 difficult to make. Exact costs for the system will depend on the type
 of  contaminants  in the waste water to be cleaned, the concentration
 of  these contaminants, and the quality level of cleaning which is
 desired.  The fixed costs,  i.e. the cost of the machine(s) can range
 from  21,000  DM for a single stage machine with a capacity of 300
 liters per hour,  to 750,000 DM for a multi-stage system with a
 capacity of  25,000 1/h.  The treatment costs are even harder to
 generalize.  They range from 0.3-3 cents per gallon if only a single
 stage treatment  is required,  to 2 - lOc/g for water requiring
 multi-stage  treatment. However,  most waste waters require in the
 range of  2 - 5  c/g for  cleaning. Examples may be helpful:

 Single Stage Treatment                                         \

      Single  stage  treatment consists of a single Peipho machine,  with
 capacities ranging from  300 1/h to 25,000 1/h,  and the appropriate
 mixture of chemicals.  This  is  researched by our laboratory  for the
 particular water  to be cleaned.  The water is pumped into the machine
 where the  chemicals are  added  and mixed with the water at high
 speeds, allowing  coagulation/flocculation to take place.  This water
 is  then moved  into the sedimentation tank where the sludge  is removed
 automatically  by a filter band.  The water must  pass through  a filter
 before it  is discharged. The result is  a treated water and  a sludge
 which has encapsulated the  contaminants  and which,  according to the
 "Wehrwissenschaftliches  Institut  fur Material Untersuchung"  (State
 Scientific Institute for Material  Study),  was not susceptible to
leaching over  the  term of a one  year study using distilled water  and
a sludge contaminated  with  hydrocarbons.                        ',
                                     120

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      THE PIEPHO CORPORATION
      9341 Cornwall Farm Rd. Great FaUs, Va. 22066, (703) 759-7074
     Costs:  The costs for a single stage system are as follows.

        Machine:   21,000 - 300,000 DM
        Chemicals - Generally 0.5 - 3.5 kg are used per 1000 liters.
                    1 kg costs 3 DM

                    Treatment costs are therefore 1.5 - 10.5 DM per
                    1000 liters or 0.3 to 2 cents per gallon.

                    Other costs such as electricity, labor, and
                    filter paper are insignificant.


Multi-stage Treatment

     The full treatment offered would consist of the following.
     1) Pretreatment - Skimming off of low density materials.
                       Screening of solids.

     2) Stage 1 - Same as a one stage treatment.  Just  a  single
                  machine and the addition of NT  75.

     3) Stage 2 - A tank and a mixing turbine for the  addition  of
                  activated carbon.

     4} Stage 3 - The same setup as stage 3, only here it  is  for the
                  addition of a special Fuller's  earth mixture.

     5) Stage 4 - A machine exactly like that in  stage one. Here NT
                  75 is used to coagulate the pollutant  loaded
                  absorbents from stages 2 and  3.

     6) Stage 5 - In exceptional cases, a membrane process or a
                  biological reactor can be  integrated into the
                  Piepho process.
Fixed Costs:
     Pretreatment - oil skimmer                        6000 DM
                    solid screening  process  -   market price

     Machines -  2 are needed  (stages 1  and 4)
                                          20,000 to 300,000 DM each
     Mixing tanks  -  (2)
approx.
            30,000 to 50,000 DM each
                                     121

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       THE PIEPHO CORPORATION
       9341 Cornwell Farm Rd. Great Falls, Va. 22066, (703) 759-7074
      Additional treatment - Membrane  or  biological  reactor
                                          market  price   ;
      Total cost -
                            approx.  100,000  to  750,000  DM -  this  does
                            not include  additional  treatment
 Treatment Costs:  ( per 1000 liters)

      Pretreatment - liquid separation agent  (3 DM/1)   =           3  DM

      Stage 1 - NT 75 (0.5 - 3.5kg at 3 DM per kg)      =  1.5  -!l0.5  DM

      Stage 2 - Active carbon (0.5 - 3 kg at 5 DM/kg)   =   2.5 -  15  DM

      Stage 3 -'Fuller's earth mixture(0.5-3.5* 3DM/kg)=  1.5  - 10.5  DM

      Stage 4 - NT 75 (0.5 -3.5 kg)                      =  1>5  _ jlo.5  DM

      T°tal                                             =  10-49.5  DM

                                         or 2 to 10 cents per gallon
                                                               I


            POSSIBLE  USES  OF THE PIEPHO  PROCESS IN THE U.S.


We see  three  areas where  our  process  could be used in the U.S.'
                                                               I
«i« °lean  contaiminated water at  its  source of  contamination;  i.e.
sales to industry. This is the  area where  we  have been most
JUS?!?   J in ?urope- Our ran^e of Products  allow us to treat a  wide
variety of wastewater streams.

2) Cleaning contaminated  groundwater  and surface  waters,  under
Superfund and other similar state laws. We have had  plenty of i
J«SaJi*nCf in t£ese areas  in Eur°Pe and our products  are  well suited
ror this type of use.                                          I

3) Using our technology as part  of a larger process  to  clean   '
contaminated soil. We have found two ways in which this can begone.

        a)  Using our process in  conjunction with  a mobile soil
        washing plant. This plant uses specially  pretreated water to
        wash the contaminants from the soil. The  contaminants end up
        in  the washing water and are removed using the  Piepho
        process. Plants of this type will soon be in production in
        Europe.
                                     122

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THE PIEPHO CORPORATION
9341 Cornwell Farm Rd. Great Falls, Va. 22066, (703) 759-7074
  b)  Using our technology as part of  an  in  situ soil flushing
  process. In this case we would force specially treated water
  through the contaminated soil. The  water  would pick up the
  contaminants as it flushed through  the soil.  This process
  would be repeated until the required levels  of contamination
  had been reached or until the water could no longer remove
  any contaminants from the soil.                *
                               123

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        REGIONAL  BIOLOGICAL 'DECONTAMINATION CENTERS  |
                    FOR THE CLEAN-UP OF              '
   CONTAMINATED SOIL,  SLUDGES  AND INDUSTRIAL WASTE-WATERS
                   A PRESENTATION FOR THE            :
EPA-FORUM ON INNOVATIVE TREATMENT TECHNOLOGIES: DOMESTIC AND
        INTERNATIONAL, ATLANTA,  JUNE 20-22, 1989
                             BY
        DR. HEIN KROOS, PRESIDENT  AND GENERAL MANAGER,
           BIODETOX GMBH, 3061 AHNSEN, WEST GERMANY  :
                          124

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Introduction
          Thank you  very much  for  your kind  invitation  to
          discuss  the biodetox decontamination  technology
          with special regard to our  concept for biological
          clean-up  activities  in  regional  decontamination
          centers.

          There is sufficient scientific proof that oil con-
          taminated soils and sludges can more or less easi-
          ly be cleaned  biologically  once  the preconditions
          for biodegradation  have been  established.  In West
          Germany  and surrounding countries  virtually hun-
          dreds  of thousands  of tons  of  oil contaminated
          soils were cleaned that way during the last years,
          with biodetox  being one of  a  number of specialist
          companies  working  since  1981 in this  field and
          offering a broad range of services including field
          expertise,  analytics, hazard  evaluation  and spe-
          cial  decontamination  services  based  on  various
          patented  biological  clean-up  processes  which can
          be used either in situ or on  site.

          As a result of these  years of field  experience and
          discussions  with the regulatory  authorities the
          "Bio-Pit"-process  for biological clean-up activi-
          ties, which is especially suited for temporary on
          site  or  permanent  decontamination centers,  was
          developed.
                            125

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                           2
                           3
                          4
foaming process
filling process
deep-ground
  process
grouridwater
  process
            unsaturated zone
             e.g. clay
     foaming process

     rotary cutting
     irrigation
     producing well
               producing  or
               injection well;
               bio reactor

               contaminated
               soil /qroundw.
                                     uncon lamina ted
                  aquifer |
                          i
                  addition .of
                  microorqanisms
                                         water back flow
                                     126

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Special purpose of  this  presentation  is to demon-
strate this proven  process  which has  been equally
accepted by the German Federal  and State Authori-
ties as well as by the public including the neigh-
bouring  communities.  This   process  is  presently
running successfully  in  a  number of German regio-
nal  decontamination  centers  combining  regional
private initiative with  the central R & D-quality
control and marketing facilities  of  a nationwide
franchise system.  The process is economically fea-
sible, without receiving government or state sub-
sidies whatsoever.

The biodetox Bio-Pit process consists of following
steps:

Contaminated soil  is  transported  to  high density
polyethylene treatment beds  and  receives on arri-
val a pre-inocculation with the appropriate micro-
organism  cultures  (biofoaming).  Water  is  then
sprayed over the  treatment  bed,  percolating down
to a  drainage  system which  leads  to  a collection
sump and is then  pumped  to  an aerobic bioreactor.
The  bioreactor is  filled   with   fixed,  vertical
sheets or other filling material, on which biomass
either especially  cultivated for  this  purpose  or
as a standard mixed culture grows. The reactor  is
aerated at  a  rate of  4  m3  per  m3 reactor-volume
per hour and has  a  hydraulic rentention time of 6
-  12  hours. There  the  dissolved  pollutants  are
finally degraded  should that not  have  happened  in
the soil already. Therefore,  we  have  clean-up ac-
tivities at two  stages:  First in  the  soil itself
(the problematical blackbox!),
                 127

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and then  in  the reactor with its more homogeneous
medium, especially  suited for biodegradation; The
cleaned water  passes  into  a transit  tank tyhere
nutrients  and additional biomass can  be added as
required.   The water is then  pumped to the treat-
ment bed  via the irrigation sprays establishing a
closed loop  system.                           |
                                              j

The following schematic  illustration  of the :Bio-
Pit process  will  demonstrate these  details 'more
clearly.  Initially, only soil  contaminated ;with
mineral oil  products such  as gasoline,  kerosene,
diesel fuel, motor oil, lubricants  and heating oil
were treated  in bio-pits. Meanwhile a broad range
of  other  pollutants can be  treated successfully
including  light aromatic  compounds such  as  ben-
zene,  toluene, xylene,' styrene, cresol, phenol and
phenolic  compounds  plus  the  so  called  coal' tar
constituents  (PAH).                           ;

Degradation  time for  oil  contaminated  soil! has
been found to be between  6 to 12 weeks on the'ave-
rage.  The following degradation diagrams will '• show
some average values.                          ,

Regarding other pollutants, biodegradation is lar-
gely depending  on their  chemical formula, concen-
tration and  agglomaration,  the soil character; and
                                              i
structure  and the presence of toxic or potentially
toxic  metabolite forming agents.              j
                  128

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  BIO-PIT  PROCESS-SCHEMATIC ILLUSTRATION
bioreactor
             circulation
              tank
                    irrigation
                    pump
                                         irrigation
fa   fa  A
                              HOPE-foil
                           bio-pit
         pump

-------
                                         SOIL CONTAMINATION (DIESEL FUEL) mg/kg
co
o
CD

O

TJ

H

T)
7)

O
O
m
                                                                                                                      on

                                                                                                                      5
                                                                                                                      o
                                                                                                                      m
O
>


6
                                                                                                                      c


                                                                                                                      in

-------
                     BIODECRADATION RESULTS



                         BIO-PIT PROCESS
   3.000
  (mg/kg)



   2.800 .
   2.600




   2.400 _




   2.200
01
    2.000
o>

_  1.800
UJ
to
    1.600
-  1.400
z
O
h-
<
I-
z
Q
O
o
t/v
1.200
1.000
      800
      600
      400
      200
                                BIO-PIT # 1/CH 5



                                    range of value



                                    average value



                                    clean-up  target
                         2        4


                       treatment time
                                                          10 (weeks)
                     131

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                        BIODEGRADABLE ORGANIC POLLUTANTS
                               (BIO-PIT PROCESS)
         MINERAL OIL PRODUCTS
         - GASOLINE
         - DIESEL FUEL
         - MOTOR OIL
         - LUBRICANTS
         - KEROSENE
         - HEATING OIL
            LIGHT AROMATICS
            - BENZENE
            - TOLUENE
            - XYLENE
            - STYRENE
            - CRESOL
            - PHENOLS
            - PHENOLIC COMPOUNDS
            - XYLENOLES
CO
ro
                   POLYCYCLIC AROMATIC HYDROCARBONS (PAH); e. g.
                   COAL TAR CONSTITUENTS
  - FLUORENE
  - PHENATHRENE
  - ANTHRACENE
  - PYRENE
  - FLUORANTHENE
  - BENZ(A)ANTHRACENE
._^_CHRYSENE		 --
  - BENZ(A)PYRENE
  - BENZ(B)FLUORANTHENE
  - BENZ(K)FLUORANTHENE
  - DIBENZO(A,H)ANTHRACENE
  - INDENO(1,2,3-C,D)PYRENE

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Extensive research work has  be  done,  e.  g.  regar-
ding biodegradation of  polycyclic  aromatic  hydro-
carbons, found on  former  gasworks  sites.  They can
be actively biodegraded by a modified Bio-Pit pro-
cess, using  especially cultivated  microorganisms
either  isolated  from corresponding  sites or  di-
rectly taken from  the incoming  soil  and  being re-
injected after  enrichment plus  the  use  of  other
biomechanical means such  as  bioemulgators and the
application of  some  special machinery, which  was
developed for this purpose.

The  following  pictures  will give  you an idea of
the  Bio-Pit  operations  in various Biological  De-
contamination Centers, starting with a generalized
view  of biodetox1  own Biodecontamination  Center
which its  pilot  and  R & D-facilities for  other
centers.

The  then  following pictures will  show additional
biodegradation  aids,  closing  with a  schematized
plant for  the processing of polycyclic  aromatic
hydrocarbons. It can only be shown  as a  presenta-
tion as  it  is just presently  under  construction.
These pictures will  be  followed by a  process  de-
scription showing  the treatment of oil-/gasoline-
and sandtrap-residues (oil sludges)  as an additio-
nal  moneymaking  proposition  for these  treatment
centers.
                 133

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                                                                                                                             Biological  Drciiiilniiiiiinlinii OM|IM

                                                                                                                    for  the  purification of cmitnminntrcl 
-------
Coming back  to the  initial  schematized presenta-
tion of  biodetox1  own  Decontamination  Center you
will  have noticed   that  it  encompasses a  whole
package  of  activities,  contaminated   soil  being
just one  of  them.  The  speciality  of this concept
is that it can be expanded in modules, horizontal-
                                              i
ly as well as  vertically.  A regional decontamina-
tion center can be  e.  g.  started with one or more
open pits  including  the specific treatment equip-
ment.

Then a hall can be added, where especially gaseous
materials can  be  handled and the  exhaust  air can
be treated  by a biofilter.  Then  e.  g. equipment
for  the  treatment  of  oil-/gasoline-  and sandtrap-
residues.  (oil  sludges)  can be  added.  The process
was already explained.

The bioreactor farm where polluted waste water can
be treated is based on an original idea of our re-
gulatory  authorities and can be seen  as  a  third
step. Due to the restrictive  fines for the uncon-
trolled  delivery  of  highly  polluted  industrial
waste waters into municipal treatment plants, espe-
cially small companies, unable to finance expensi-
ve waste water pre-treatment equipment, would have
had to be shut down if there had not been an alter-
native.  Therefore the  regulatory authorities pro-
posed a bioreactor  farm as an  appendix to biode-
tox'  biological decontamination center to serve as
a pre-cleaning facility for firms within our vicin-
ity including food and vegetable industry, slaugh-
ter-houses and others.
                  135

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This bioreactor  farm will be used as well for the
treatment  of  cleaning fluids  from  a washing sta-
tion  for multi product  tank trucks, where deter-
gents,  disinfectants and a  high  quantity of wash
water are  producing  waste water highly loaded with
BOD/COD.                                       !

Presently,  3  Regional Decontamination Centers are
in operation,  2 are under construction  and  5 ! in
various  stages of planning. The economical operat-
ing radius  is at roughly 150 miles each. Every qne
of   these   centers   is   strictly   based  'on
non-subsidized  private regional  initiatives,  the
operators  being  private  companies,  usually coming
from   related   fields   of   activity    such  jas
construction, hauling or waste removal.  They are
cooperating with biodetox  on the  basis  of a gene-
ral franchise agreement.                       j

The biodetox  franchise package contains start-4up
assistance  by a way  of expertise, blue  prints and
all red tape  processing  regarding  the  Government
and State  permits,  a complete legal and admini-
strative package  regarding waste handling  trans-
port and acceptance  as well as protection against
product  liability. Furthermore, biodetox manufac-
tures and  ships  the  equipment and biochemicals  to
the regional decontamination centers and monitors
the biodegradation  processes,  from  time to  time
improving on the specific  formulation and the me-
chanical process  engineering with regard  to  spe-
cial pollutants.                               !
                  13£

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At the  same  time,  biodetox runs  its  own Regional
Decontamination  Center  at  the  company  seat  with
special  facilities  for  an  extensive  research and
development.   R & D is  jointly  conducted with  a
number  of universities  and  research institutes.
All R  & D results  are  communicated  to  the  fran-
chisees  in order to further  improve  their biode-
gradation process  and reduce the  costs  involved.
This  way, biodetox ensures  a  consistently  high
quality  standard of operating methods nationwide.

The average clean-up charges including an adequate
profit-  and  risk  margin  for  oil  contaminated
soil, are at  380,00 DM  per m3 or 140 US $/cu-yd.,
based on a soil  kf-factor of  10~    and 3 % equal-
ing 30 000 mg  (ppm) diesel  fuel per kg of soil be-
fore and 500  ppm after  a twelve week decontamina-
tion process.

The initial  investment  for the erection  of  a re-
gional  decontamination  center as  described  would
be between 500 000  and 1,5  Million US-Dollars with
an amortisation rate of ca., three years.

Last  not least, you  might be interested  of what
happens  to the decontaminated soil after clean-up.
Here an  agreement  with  the regulatory authorities
has been reached to  the extent that  soil with  a
threshold-level  of  equal  or  less than  500  mg of
mineraloil hydrocarbons per kg of soil can be used
for  agricultural  purposes.  Other  material  with
threshold-levels  at or  above 500  mg up  to 1000
mg/kg may be used as cover  material for landfills,
as road  building material or  for noise protection
                 137

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walls. Another precondition  being  that  an  analysis
must  prove that  there  are  no  soil pollutanjts  at
the new  site  which would add to a  further acicumu-
.Tation of  pollutants.                        j
                                             j
Obviously, biological clean-ups, such as conducted
in regional decontamination  centers cannot be  suc-
cessfully  applied to all hazardous wastes. Never-
theless, applying it to all sorts of lower class
hazardous  wastes  as already  described   pre'cious
land  fill  space  and treatment costs can be slaved.
Furthermore,  biological  clean-ups  are lasting and
final. There  is  no problem  transfer into  the fu-
ture  or  to another place and there are no  topical
residues that have to be taken  care of.      i"
With  regard  to  these  facts  the  German  Federal
Government  and  the governments  of  various German
states are presently giving priority to biological
clean-up- and recycling  methods.  New laws and re-
gulations under way will stress this comittmeht to
assist nature to help itself.                ;

I would now like to summarize and to add that! biode-
tcx as interested in licencees worldwide.    !
Thank you very much for your attention.
                                             I
                 138

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       Biological  remediation of contaminated groundwater  and soil -
          Concepts of remediation and their technical application

            M. Kastner 1), K. Hoppenheidt 2),  H. H. Hanert 2)
       Department of Biotechnology;  Technical  University of  Hamburg-
      Harburg. Harburger SchloBstr.  37, D-2100 Hamburg 90, F.R.G.
       Institute for Microbiology; Technical University of Braunschweig
      Biocenter, Konstantin Uhde  Str. 5, D-3300  Braunschweig, F.R.G.
Summary:

   In this paper different ways to develop biological processes for the remediation
   of contaminated soil and  groundwater are discussed. With dichloromethane
   as  an example  it  is  shown how  elimination  processes  can  be  developed
   which are designed for a specific organic  pollutant and specific bacteria
   (Such developments  are  often to  be  found in literature).  The  fixed-bed
   reactor process presented here is able  to achieve results of decomposition
   of  dichloromethane from  groundwaters  of  4,2 kg/m  * d.  These results
   could be  maintained for  more than  six  months. As  in  many contaminated
   sites bacteria adapted to the  organic pollutants are  already existing,  the
   example of a contamination with complex organic compounds will be used to
   show the activation of the microflora from the site  to  degrade  the organic
   compounds and  its technical application  in remediation  as another way  to
   develop processes. From  these investigations  a concept of  action was de-
   veloped which permits  statements about the possibility  of biological reme-
   diation  of a contaminated site  and the processes which can be used, even
   with  relatively few experiments. This concept  facilitated the  application  of
   biological processes  to different  organic pollutants in all cases  examined
   until  now.


Recent  studies  show  that many microorganisms  are  not only able to  degrade
natural  organic substrates,  but also  synthetic  organic  compounds  and compo-
nents of petroleum. This degradation was mostly to be  found  under special
laboratory  conditions, where after suitable times  of adaptation  the parameter
of the respective  metabolism were  optimally adj.usted. Compounds,  however,
which reached the environment as organic  pollutants or hazardous  compounds,
are persistant in most cases, or  are only slightly transformed by the biological
activity. If natural compounds were introduced in concentrations not excessively
high,  on the other  hand, they were mineralized by  processes  of  bacterial
self-purification,  which made use of  the  whole  spectrum of  biological  types
of metabolism. In the  course  of this  the organic compounds  may  serve  as
donator and acceptor of electrons,   respectively. The  different processes  of
self-purification in soil and  groundwaters are represented as biological redox-
processes  in Figure 1 .
                                 139

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                         OS
                                         +0.5

REDU
<

KTION








<^02 •Hcduktion |

( Otnibilikalion |

^WIY)o«y«- Mntt






biydoLvonHnW)^


[Nj-NOj >

|0;-0ildur>9




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                      -TO
                           -5
                                                     20 pe
Fig.1:  Biological  redox-processes as natural self-purification  processes  in
       soil and groundwater  (translated from H. Schwoerbel,  1984-)   i

In technical microbiology these microbial self-purification processes are a ready
used to compost organic waste, for sewage treatment, for treatment of waste
gas  and for the production of drinking water.
Own investigations at different contaminated sites  in the  Federal  Republic of
Germany  revealed the existence  of a microflora which  is  already  adapted to
the organic pollutants, but is evidently unable to develop  its activity. Ini many
research  works described in literature, dealing  with the  bacterial degradation
of specific  organic  pollutants in  the .environment,  the bacteria were isblated
from  contaminated  sites  as well.  From  that two  questions  concerning  the
remediation of contaminated soil and groundwaters  follow:
Why don't the self-purification  processes work on  organic pollutants  n  the
environment, too?                                                     I
How can remediation-processes  be developed from the results of the experiments
in laboratory  ?
Principally it is  to be noted  that in contrast to  chemico-physical processes
microbiological processes  can be standardized neither in situ nor on site,  as
nearly  all  contaminated sites are to be differentiated  because of their different
                                      140

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conditions. Technical instructions  or standards  thus are  not yet  in  sight.
However,  for  the conception of  a biological remediation and  its  necessary
microbiological investigations the way of proceeding can be explicity formulated,
as will be  explained later  on.
First of all, the two following  methodological approaches are to be differen-
tiated:

1).  Isolation  of special  bacteria,  which  are able to degrade a specific organic
     pollutant  (possibly the genetic optimization of the strains,  too) followed
     by the development of processes which are  suited  to the  substance
     which is  to  be degraded  and the respective  bacteria.

2).  Stimulation of the microbial  activity of the contaminated site by investi-
     gations of microcosms, which  are suited to the usable  physiological type
     of metabolism. The second method has the advantage of allowing  direct
     statements about the  possibility of a remediation of the respective  site
     and the  determination of suitable concepts of processes.

The  first  approach can be explained with  the example of dichloromethane de-
gradation.  From different contaminated  sites  caused by  dichloromethane pure
cultures of Hyphomicrobium species were isolated. These strains are  able to
grow aerobically  with this substance in  concentrations  up  to  1  g/l medium
as the sole source of carbon and energy. As these  bacteria are known to  in-
habitate rapid-sand filters  used in  water  supply  plants,  and these  technology
is generally used, the idea of  using the  same technology  for the remediation
of contaminated groundwaters suggested  itself, in order  to  keep problems of
the scale  up  to full technical  scale as  small as possible. For the  continuous
degradation of dichloromethane in  a modell  groundwater a fixed-bed reactor
inoculated by  one  of the isolated  strains was operated. The  fixed-bed reactor
corresponds to the technology of rapid-sand filters and shall prove the principal
suitability  of this technology. The process scheme of the reactor is represented
in Figure  2.
The degradation power reached by this reactor and the calculated values from
that for 1 m3 plant volume are represented in table 1. The  degradation could
be kept stable for more than six months.  During this time the used  strain was
not  overgrown by other bacteria.  Produced  biomass was  removed by  back-
washing of the fixed-bed  material, at any one time  when 1 00 g of dichloro-
methane were degraded. The degree of efficiency as  well as the concentration
of the influent and effluent  after a backwashing is shown in  figure  3.  As
these results show that this  process can  be used  in technical  applications.
Nevertheless  for  a concrete contaminated  site further  experiments with  the
respective groundwater have to be carried  out.
                                 141

-------
         b
         c

         d
         e
         f
         g
Stock solution  (water,1 50 I)         h
Oxigenator                         I
Membrane pump (circulation of
gas)                               j
Stock solution (Mineral  salts,  DCM)
Peristaltic pump                    k
Sample  port                        I
Backwashing  drain
                        Fixed-bed  reactor (2 l,r=|4cm)
                        Quartz sand  (1 .7 I;       i
                        pore space: 0.28 I)       j
                        Sample port  and          !
                        backwashing  inflow        '•
                        Effluent                  '
                        Backwashing  pump
         Fig.  2:   Process scheme of the fixed-bed  reactor for the removal
                  dichloromethane
         Table 1 : Dichloromethane  removal of the fixed-bed  reactor
         velocity of influent;
         detention  time*)
           ml/h  ;  min.
           2623    6.6
           524-6    3.3
          104-92    1.7

         vel. of infl.;        load
         det.  time*)         DCM
           ml/h             mg/h
           2623            129.0
           5246            281 .7
          104-92            619.0
    influent
  DCM    Cl~
     mg/l
4-9.2     6.8
53.7     6.8
59.0     5.8
                                       effluent
                                      DCM   Cf
                                        mg/l
                                      n.n     26.6
                                      n.n     27.3
                                      2.9     29.8
 ADCM
from  ACI
  mg/l
  23.5
  24.2
  28.4

              DCM-removal
                 reactor
                  mg/h
                  61 .5
                 126.9
                 298.3
                                                     DCM-removal
                                                         3       I
                                                    per m  plant v'p\.
                                                       g/m3xd  j
                                                          869    j
                                                         1792    !
                                                         4212    i
          effective detention time in  pore  space
_
                                               142

-------
 Efficiency
   in  %
             Dlcnloromeihane
                  mg/l
100
              80
              60
              40
              20
                  50
                  40
                  30
                  20
                  10
                                                   Efficiency
                                                                    Influent
                                                                   Effluent
                                     10
                                15
20
25
Fig.  3:   Dichloromethane removal  of  the  fixed-bed  reactor  with  backwashing
         (arrow)

The second methodological approach can be exemplified by a special contamina-
ted site  in a solvent recycling  factory. The contamination of  groundwater and
soil  consisted of  a  complex mixture  of  aliphatic  and aromatic solvents and
volatile chlorinated hydrocarbons. In diethylether-extracts  from soil and ground-
water over 70 single substances could be detected by gaschromatography. The
contaminated area had a size  of  10000  m2, the area  of the  contamination
centre covered 1 200 m2.  Until  a depth of  25 m (level of groundwater: 4.5 m)
the contamination  was proved.  It is estimated that altogether 4-0-50 t of ali-
phatic and aromatic compounds  and 4-5 t  of  volatile chlorinated-hydrocarbons
had seeped  into the soil  here.  In the soil organic contamination (per  kg dry
weight)  up to 600 mg/kg of aliphatic and up to 700 mg/kg  aromatic hydro-
carbons  were  to  be found.  At  some  points  the concentration  of chlorinated
hydrocarbons  reached  4-60  mg/kg.  The  contamination  of  the  groundwater
amounted up to  19200 mg COD/I as summary parameter  for the organic
contamination  and up to 150 mg/l for the volatile  chlorinated  hydrocarbons.
Because of the high contamination and the resulting costs for a  chemico-rphysical
remediation  it was decided to examine if the site could be remediated biologi-
cally. The compound consistence had the consequence that biological remediation
processes designed for specific  organic pollutants and bacteria could  not be
used here.
                                 143

-------
As  a  result of this the microbiological  investigations of the site were carried
out under different aspects. Besides the determination of the numbers of bac-
teria in groundwater and soil  in dependance of the concentration of the organic
pollutants, parts  of the investigations applied to the degradation of the highly
contaminated groundwater. After various pre-experiments  a laboratory sevyage
treatment plant with a closed circulation of gas was developed for this  purppse.
The process scheme is represented in  figure  4-. The average COD-loading  of
                               Q                                      I
the plant amounted to 0.73 kg/m x d, the loading of volatile chlorinated hydro-
carbons amounted to 3.4 g/m3x d. With a  suitable feeding of mineral nutrients
and electron acceptors (OJ, an  activated  sludge developed from  the  bactjeria
of the contaminated  site reached  average removals of  95  %  COD  (influent:
5490  mg/l; effluent: 250 mg/l) and 94-97 % of the chlorinated hydrocarbons
with a residence  time of  7.5  days  in the plant. The  mineralization of the
toxic  chlorinated  hydrocarbons  could  almost completely  be  assessed by' the
                                                     a
                                                     g
                                                     m
Mineral nutrients
Groundwater   !
Septum ports  \
O2-stock  (gas  Ibag)
Reactor
Sedimentation
vessel
CO -absorption;
vessel          !
Gas  supply
Magnetic stirrer
Siphon         |
Peristaltic  pump
Membrane  pump
               !
Effluent        I
                                                                       }6.5I
Fig. 4:  Process scheme of laboratory sewage  treatment plant
                                       144

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release of chlorine as  chloride ions.  Concentrations (influent and  effluent) of
the chlorinated compounds as well as the concentrations of the chloride ions
are represented  in figure 5. Table 2 summarizes  the  distribution  of  specific
chlorinated  hydrocarbons  and release of chloride ions  made  possible  by this.
Batch  experiments show  that perchloroethylene  could  only be  decomposed in
a small amount by the  activated  sludge;  that is why at higher  concentrations
a side-reaction of this substance has to  be made use  of. With  a  shortage
of oxygen  the  sludge dechlorinated  tri-  and perchloroethylene  by way of re-
duction to cis-1,2-dichloroethylene very fast. By  insertion of  a  unaerated col-
         CKH ug/1 fCHC]
          60000
          50000

          40000

          30000

          20000

          10000
                                      Zulauf .
                                    Influent
                                                             Effluent
                                                            ^ flblauf
              0    10    20    30   40    50   60    70    80    90    100
                                                                     d
          Cfng/1
           140
            120
            100

            80
            60
            40

            20

             0
                                      flblauf
                                    EffluentJ
                                      Zulauf
                                    Influent
                   10
20   30
40
50
60
70
80
30
11
Fig. 5:  Influent and  effluent concentrations  ( summarized  volatile  chlorinated
        hydrocarbons and chloride ions) from the laboratory sewage treatment
        plant
                                  145

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  Table 2: Distribution of volatile chlorinated  hydrocarbons  and chloride1 ions.
           average  concentration of  influent  and effluent  from  the  laboratory
           sewage treatment  plant
                            Effluent
                              HO/1
  Vinylidenechlorid
  Dichloromethane
  1,1 -Dichloroethane
  cis-1,2-Dichloroethylene
  Chloroform
  1,1,1 -Trichloroethane
  1,2-Dichloroethane
 Trichloroethylene
 Perchloroethylene
 E CHC

 Chloride
    21.7
22558
   662
21342
   363
   153
   435
  5471
    40
51046

57500
Influent Removal
ug/i
0.5
28
183
1167
62
27
n.n
227
1.2
1695 A= 49350
(* 38800 CD
100300 A= 42800
/»
97.


99.8
72.3
94.5
82.9
82.3
(99.9)
95.9
97.0
96.

—



 lection vessel for the return sludge (1 I;  16 h residence time)  and the feuding
 of the groundwater  into this vessel the  available amount  of trichloroethylene
 could be transformed into cis-1,2-dichloroethylene (Batch  experiments \ with
 perchloroethylene showed the same effect). The increase of cis-1 ,2-dichjoro-
 ethylene  concentration and the  reduction of trichloroethylene concentration  in
 this  experiment is represented -in  figure 6.                             j
            Tri pD/1
             300
            200
            100
                                     Cis
                                       3B08
                                                          Tri
                                                          Cis
                    t4 T  8   T   12    T 16 Th
                      10
    20
30
40
50
                                                                  2000
                                                                 1000
Fig.  6:  Effluent concentrations  of  the  laboratory  sewage  treatment plarjt at
        different anaerobic  residence  times of the  backflowing  activated
        sludge                                                           j
                                       146

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In  corresponding experiments  with  soil columns  from the centre  of  the  con-
tamination  the  degradation  of  the organic pollutants  by  the  bacteria  from the
soil could be activated with the addition  of minerals (fertilizer) and electron
acceptors like O2 and nitrate. But a detailed degradation balance of the volatile
chlorinated hydrocarbons could not  be carried out in the soil because of  ana-
lytical  problems.
The  results  represented here show  that  in  contaminated  sites with such  a
complex composition of pollutants the biological  power  of self-purification of
the soil and groundwater can be activated if conditions are  chosen adequately.
The  persistance of  the organic pollutants at  this site is due to the  limitation
of mineral nutrients and  electron  acceptor  supply.  It can be derived  from
the results of the soil  experiments that merely  the addition of  nitrate-con-
taining  fertilizers in connection with  atmospheric precipitates led  to  an elimi-
nation of the organic pollutants. Thus the  soil of the site  could  be used as
an in situ  fixed-bed reactor  with  a  remediation time  of approx. two years.
The  seeping  of dissolved fertilizer in injektion wells without hydraulic  water
movement  showed the same results for groundwater. The  addition of fertilizer
was watched with special  sampling  systems  in  order  to keep the  supply of
nitrate as  an electron acceptor constantly  limited against the  carbon source.
With this secondary contaminations with  nitrate could be avoided  safely.  This
process of  remediation  manages nearly  completely without the  building of
plants above ground and causes only approx. 1 /20 of  the expense of a chemico-
physical remediation. At the moment the  remediation  in  a technical  scale  is
carried out and has led to a 60-70  % reduction of the organic pollutants at
the  site after  just  1 .5 years. The details  of the remediation will  be reported
in international journals when the  project  is  concluded.
A summary  of the  pre-experiments  at the site described  above  also  reveals
a  microbiological concept  for the  investigations of  a  site which has  to be
remediated.  This concept  will be  explained  finally.  The  investigations  mainly
have to answer the eight following questions, from  which  the possibility  of  a
biological remediation  and  the technical process to  be applied  can be derived.

1).   How  is the  biological state  of  the contaminated  site ?
      (quantitative determination of the complete population of  bacteria,  fungi
      and actinomycetes; comparison  to the  situation at  the periphery of the
      contamination; evaluation of the toxic effect of the pollutants upon the
      microflora)
 2).   What are the rates of respiration activities  of the microflora of  the site ?
      (physiological  evaluation of the  self-purification power of the site; re-
      spiration  of organic  carbon  sources with and  without optimal  supply  of
      minerals  and  electron acceptors)
                                   147

-------
 3).
 4),
 5).
6),
7).
       Does a microflora adapted  to  the  organic pollutants exist in  the site ?
       (site specific  and pollutant specific  evaluation of  the self-purification
       potential  under optimal  conditions)                                 !
      What are the reasons of  the  inhibition of the microbial self-purification
       processes at the site ?                                          :
       (evaluation of the site specific inhibition  potential: toxicity  of  pollutants,
       electron acceptor  or  mineral  limitations)                         j
       How quickly is the biological self-purification carried out with  an optimal
      supply of nutrients ?                                              I
       (kinetics of the self-purification in  batch experiments with  discontinuous
      addition of nutrients; determination of the duration  of  remedial  acjions)
      Which degree  of  purification  can be  achieved  ?                  i
      (the degree  of purification  should  not fall  below  90  %. at least under
      laboratory conditions; determination via summation parameters; for areas
      with contaminations of chlorinated hydrocarbons, polycyclic aromatic hydro-
      carbons, chlorinated aromatic hydrocarbons, mineral and tar oils, according
      to previous  experiences  corresponding powers of purification  are to be
      achieved even  if the  contaminations  amount to  the  area  of  g/kg.}
      Are organic/anorganic intermediary  products with toxic effects on human
      beeings  produced  during the purification and  how much time does  the
      microflora needs to eliminate  these substances, too ?             |
      (e. g. accumulation of vinyl-  and vinylidenechloride or  nitrite  in the rrjieta-
      bolism of  volatile chlorinatd  hydrocarbons)                         i
      Which technical process should be  applied  to  remove the  pollutantjs  on
      the  basis  of  the  experimental  results in  connection  to  the situation at
      the  site  (extent of pollution; who or what is endangered  ?; which use is
      intended for the site)  and under aspects of economy ?            ',

The design of experiments  has to be developed in accordance to the  specific
contaminated  site; that means the physiological status quo has to be  adapted
to the physiology of the degradation  of the organic pollutants (see also  fig;. 1).
In this not single the tests  of  bacteria or substances are  concerned  primarily,
but degradation tests of mixed  populations  under specific physiological conditions
which are possible. The answering of the questions in a  phase  of  laboratory
tests of approx. 4 months and the testing of the resulting concepts  of re|me-
diation in a half-scale technical phase of also approx. 4  to 6 months led  to
the development of the remediation process for the  site desribed above. This
concept  of action  in  the meantime  also  led to  the  application  of  biological
remediation processes  in some cases of contamination caused by mineral! oil,
tar oil, chlorinated organic compounds originated from the production of pe!sti-
cides and  at sites of former  gasworks. The investigations represented here .
8).
                                      148

-------
allow to  make  predictions about the duration and  success of a  remediation
which is  to be  expected  in every specific  site. To this  a decisive importance
is  attached by the supervisory authorities  in the Federal  Republic of  Germany.
In  cases carried out until now the  costs of the experiments for  each  site
amounted to  10-20 % of the total remediation costs, depending on the spec-
trum  of  pollutants.

Literature:

M. Kastner und H. H. Hanert: Biologische Elimination von  Halogenkohlenwasser-
            stoffen  in belasteten Grundwasserleitern;  in: Veroffentlichungen
            des BMFT, Hrsg.: Sanierung kontaminierter Standorte - Dokumen-
            tation einer Fachtagung  1985, Berlin  1986
            (Biological elimination of halogenated hydrocarbons in contaminated
            aquifers; in publications of  BMFT  [Federal ministerium  of research
            and technology], ed.: remediation of contaminated sites —  documen-
            tation of a  special  conference 1985, Berlin 1986)

H. Hanert:  Mikrobiologische Bewertung  von kontaminierten Standorten im 'Hin-
            blick auf eine biologische  insitu-Sanierung;  S. 1 43-1 53
            (Microbiological  valuation of contaminated  sites  for biological  in
            situ  remediation, p 1 43-1  53)
M. Kastner: Biologische  Elimination von leichtfllichtigen  Halogenkohlenwasser-
            stoffen (Theoretische Grundlagen und Laborversuche);  S. 155-166
            (Biological elimination of volatile  hydrocarbons [theoretical  basics
            and  laboratory experiments]; p 155-166)
K. Hoppenheidt, H. H. Hanert: Untersuchungen  zur biologischen Reinigung eines
            organisch hoch  kontaminierten Grundwassers (CKW, Aromaten,
            Aliphaten) in einer  Labor-Belebungsanlage;  S. 167-175
            (investigations for biological cleaning of groundwater highly  conta-
            minated with organic compounds [volatile chlorinated-, aromatic-,
            aliphatic compounds]  in  laboratory  sewage treatment  plant;  p
            167-175)
P. Harborth, H. Rose: Biologische insitu-Sanierung kontaminierter B6den  und
            Grundwasser; S. 177-187
            (Biological  in situ remediation of contaminated soil  and ground-
            waters; p 177-187)
            in: Veroffentlichungen des Zentrums fur Abfallforschung  der TU
            Braunschweig: Fachseminar Bodensanierung und Grundwasserreini-
            gung -Wiedernutzung  von Altstandorten- 24.725.9.1 986  in Braun-
            schweig, 1 986
             (In: publications of the  center of  waste research, Technical Uni-
            versity of Braunschweig: special  conference  for  soil  remediation
                                 149

-------
            and groundwater reclamation — reusing of contaminated sites  —
            24.725.9.1986 in Braunschweig, 1986)                    |
                                                                     i
 M. KSstner, K. Hoppenheidt und H.H. Hanert: Bakterielle Umwandlungsreaktionen
            in CKW belasteten Grundwasserleitern - Sanierungstechnike|n; in:
            K. Wolf; W. J. van den  Brink; F. J.  Colon, Hrsg.: Altlastens|anie-
            rung '88; Zweiter Internationaler TNO/BMFT-Kongress liber Alt-
            lastensanierung,  11.- 15. April  1988, Hamburg, Bundesrej^ublik
            Deutschland; Bd.  II,  S. 1 263-1 264;  Kluyver Academic Publishers,
            Dordrecht/Boston/London, i988                          !
            (Bacterial transformation reactions in groundwater aquifers c|onta-
            minated with chlorinated  hydrocarbons — purification  techniques;
            in: ..... eds.:  contaminated soil  '88; second  international  ITNO/
            BMFT-congress in contaminated soil, 11.- 1 5. april 1 988, Hamburg,
            Federal Republic of Germany; Vol. II, p  1263-1264; Kluyverj 	)

H. H. Hanert, P.  Harborth, M. Lehmann, E.  Windt, U.  Rinkel, H. J. Scheibel,
            K. Hoppenheidt, H. Rose,  T. Niemeyer; Biologische Selbstreiriigung
            in Boden und GrundwSssern und ihre technologische Nutzung  in der
            Bodensanierung und Grundwasserreinigung;  Sonderdruck des Ver-
            eins zur Reinhaltung der Gewasser   e. V. Braunschweig, Hrsg.,
            Claus-Druckerei und  Verlag Braunschweig, April 1988
            (Biological self-purification in soil and groundwater and their  tech-
            nical application for soil remediation and groundwater reclamation;
            special print of the society for keeping waters clean. Braunschweig,
            ed.. Glaus Printers and  Publishers, Braunschweig, April 1988)

M. KSstner: Anreicherung und Isolierung von Chlorkohlenwasserstoffe abbauen-
            den Mikroorganismen unter verschiedenen physiologischen Bedirjgun-
            gen —  Abbaukinetiken und Test  auf  technische  Nutzbarkeit zur"
            Sanierung kontaminierter GrundwSsser; Dissertation  an der  tech-
            nischen Universitat Braunschweig, 1988
            (Enrichment  and  isolation  of chlorinated hydrocarbon degrading
            microorganisms under different physiological conditions — kinetics
            of degradation and test  for technical utilizability for remedi'ation
            of contaminated groundwaters; PH.D-thesis at the Technical Uni-
            versity  of Braunschweig,  1988)                            i
                                     150

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The Holzaann Svstetn for  In  Situ  Soil  Purification
1. Introduction - Disused  Gasworks  Sites

   During  the past decade  in  West Germany,  numerous  abandoned  or
   disused gasworks  sites  and coke  plants  have  been  examined with
   regards to environmental hazards.

   By means o£ the chemical processes  involved,  and  through  the
   coking process of  fossile  combustibles  considerable  amounts of
   tar oils, containing  numerous polynuclear(polycyclio)  arom.il ic
   hydrocarbons  (e.g. naphtalene),  cyanides,  sulphureous  sub-
   stances, and phenol are produced as by-products.  In  the pant,
   these by-products  were  separated, stored in  basins,  and in
   more or less suitable containers, treated, and  then  largely
   used for further  chemical  or  technical  purposes.

   Through careless  usage  however,  leaking tanks and basins,
   spillages and in  particular as a result of war  activities,  con-
   tinuous and high  rates  of  pollution have been discovered  at
   almost every gasworks and  coke plant site.

   Through the increased environmental awareness of  the public
   including the concern expressed  by  responsible  authorities
   during  the last years,  contaminated former gasworks  sites have
   aroused strong public interest.

   Most investigations carried out  on  former  sites have revealed
   serious pollution  hazardous for  soil, groundwater,  and detri-
   mental  to human health.
2. Former Gasworks  in  Bre»en-Holtmershausen

   During initial soundings  in  mid-1987  on the site of  the former
   gasworks in Bremen-Woltmershausen,  in which between  1900 and
   1964 gas had been produced,  extremely high  contents  of tar oil
   (Polynuclear Aromatic  Carbons,  PAC) and cyanides were dis-
   covered underneath  a  former  tar basin,  a  gas tank,  and a basin
   for fire-extinguishing water.

   Further detailed analyses revealed  that below the tar basin
   about 20000 m" of medium  sand  and a layer of clay containing
   sea silt are contaminated with PAC  and cyanides to a maximum
   depth of approximately 10 m.

   Soil specimens were characterised by  intensive black coloration
   and penetrant odor. Analysis of the soil-oil mixture revealed
   up to 20000 mg PAC/kq  and up to 600 rag cyanides/kg.

   Fig. 1 shows the characteristic soil  profile, grain  size
   distributions, and  the qualitative  distribution of PAC over
   depth.
 Soil Profile and Contamination
 Soil Profile        Contamination        Typical Grain Size Distribution
                 PAC ind CyinidM
 FID, S«nd
 Medium m)
 FkwSwd
 CUywilh
 SMSIIt
   o
 FkMSmd
 RMind
 MoftmSlnd
13f>

I.HIO
Fomw BIM
of tv Bum
Uuhun:
20000mg
MC/kg
600 mg
CpridM/kg
                        Lmr Migration
                        Until ol
                        Pollutants
                00020000 002 000  02 08 2  6  SO 80
                GfilnSlnkimm

                •iCIiywithS«Sit  L3 WdkmSind
Fig.l: Characteristic soil  profile  and  grain size distribution.
       Distribution of pollutants.

   A layer of silt  (clay containing sea silt)  approximately one
   meter thick lies in the  quite  uniform (U=2)  medium sand strata
   at the center of the contamination.  The ground water level
   lies approximately 2.7 m below the terrain surface.

   The highest percentage of PAC  was discovered above the silt in
   the variation range of the groundwater level. The lowest
   percentage occurs within the silt layer. The sand below the
   silt layer shows surprisingly  high PAC-contamination levels,
   partly down to considerable depth.

   The concentration of the cyanides is distributed less uni-
   formly. A slight cyanide contamination can also be npted in
   the silt.

   Buildings are located directly adjacent to the contaminated
   area, severely limiting  the space available for the soil
   purification work. Moreover, regular operations on the
   grounds have to  continue during  the  purification work.
   Fig. 2 summarises the main characteristics of the contarai-
   11,11. ion.

-------
r
                  Man Characteristics
                  of Contamination
                   Ongm
                   Sue
                   Contamination
                   Maximum
                   Concentrations
                   Soil Properties
             former tutusinolaty gas
             production punt,
             results ol war acton

             2Sx<5m'«Dd 15x32 m'
             -8mrMep.le.~t6 000m"
             next lo enstmoj structures

             MycycJicAronatic Carbons (PAC)
             Cyanides (CN)
             HI so!) and groundwater

             PACtloMfi)
                20 000 mg/kg soil (well
             CN tO:
                600 mg/kg soil (well

             - mainly medium lo tine,
              homogeneous sand
             -layer ol clay with sea sill
              ol tow permeability
                                  Treatment Methods
                                  Considered
Method


EiS4uM>crobcal
Treatment
In Situ Microbiological
Treatment

OdSiIeSo.1V/am.na

Thermal Treatment
                                                  Placement on Hazardous
                                                  Waste Dump
                                                                Reasons lot Rcteebon
                                                                 ocep ciotvnbon ncil to structure
• loo high ctmr.iirttr.it«ms
• duration

• soil profilrsancj tow pcrmc;u*Mics
• duralion

• deep excavation retiuired

• lujhcoMlixmcrm.il
 treatment above 1000 C
• complex per mission requirements

• large volumes and high cost
• deep excavation required
                                                  Chosen Method:  (n situ sod purification l>v Mali Pressure
                                                             Injection |HPl| with mechanical soil-fluid
                                                             separation and on site wall* Ircatrncnt and
                                                             off site microbiological sludge treatment
• Tlicraic purification

Te»[)oraturco between  1000'C and 1200*C  would have been
required for purification of the pollutants prooent.  This
would  have resulted in complete sterilization of the  entire
quantity of soil. A deep excavation and an appropriate
retaining structure would have increased the cost.

• UM site or off site soil washing

The high coat for the required deep excavation and  the related
groundwater lowering  ruled out t:.ese nethods. Groundwater
pumping  would have produced tremendous  anounts of contaminated
water.

Fig. 2 summarises the considered treatment methods  and the
reasons  for their rejection.  Because established methods
proved unsuitable for the given task of  soil  purification,a
new method of in situ  soil purification, developed  by  the
Philipp  Holzmann AG,  was  suggested and  laboratory tests
carried  out to optimise  the process parameters.  The new in
cilu soil  washing technique,  for which  several related pa-
tents are  pending,  wil] be described as  follows.
                                                                                                       4.  The Holziann System for  In Situ Soil Purification
          01
          IV)
Fig. 2: Main characteristics  of contamination  and  treatment
        methods considered

   3. Selection of a Suitable Treatment Method

   Disposal  of the contaminated soil at a hazardous  waste dump
   was not even considered  in detail. On the one hand,  a dump
   suitable  for disposal of such large quantities  as required was
   not available. On the other hand, the main  objective was to
   reduce  the  pollution potential  of the contaminated  soil to
   such an extent that the  prescribed limits could be maintained
   and the soil be re-used.

   The following methods were examined for suitability:

   • Microbiological treatment in situ

     Too high pollutant concentrations in the  most contaminated
     soil portions and a nearly impermeable silt layer  excluded
     this approach as well  as the long duration of treatment
     to be expected.

   • Microbiological treatment of.f  site

     Of f~silre- processes were  also" eTimTna~tea~3ue~To  the exces-
     sively  high space requirements for the compostinq  piles and
     the expense of transporting the soil. Moreover,  unless the
     soil was prewashed, the  high concentration o£ tar  oils would
     result  in intensive adhesion between the  soil particles and
     the pollutants resulting in problems for  all  niicrnhiojnni>:al
     processes.
                                                     4.1  Basic Principle of the Holzmann  In Situ Soil Purification

                                                         The first and  main step of the Holzmann in situ  soil washing
                                                         procedure is based on the meanwhile well-established con-
                                                         nlru<:tion procedure of high-pressure water injection (HPI).
                                                         Modern equipment makes it possible to inject water  into the
                                                         soil with a special rotating lance at pressures  up  to 500
                                                         bar and flow rates of 300 liters/min.

                                                         For the treatment with high-pressure injection,  the conta-
                                                         minated soil requiring purification is divided into individual
                                                         vertical borings,  each jacketed  by means of a casing. The
                                                         actual purification process is accomplished boring  by boring,
                                                         eliminating the need for a large and deep excavation and
                                                         the related groundwater lowering.  The borings overlap in
                                                         ouch a way that no soil remains  unwashed.

                                                         The purification is a multistage process consisting of  the
                                                         following parts:

                                                         -  separation of pollutants from  soil particles and  washing of
                                                           soil in situ

                                                           extraction o£ soil-water mixture from the ground

                                                    	reparation of clean-particles-f-ronr-water—and—s-ludge	—

                                                           water treatment

                                                           microbiological  sludqe treatment

-------
       - return of purified soil and water into the ground

         These steps of the purification process will now be described
         in detail.
    4.2 Stages of the Purification Process
en
OJ
          Placement of Casings

          individual cased borings are used for in situ  Boil  wash inn
          to create a clearly defined "reaction volume"  tor  the
          high-prosnure wachimj, avoiding mutual exchange of  pollu
          tants and the need for deep retaining structure;;.

          Hoisted by a rope excavator W 180 an ICE 81b vibrator  lowers
          round steel casings (9.50 m long, 1.50 m in diameter,  14  mm
          thick) 8.50 m into the ground for a treatment  depth of
          8.00 m (Fig. 3). The working platform lies 1.2 m below the
          original ground surface.

          The casings are positioned in such a way that  they  finally
          form a regular pattern of overlapping borings  across the
          treatment area. The complete soil volume is covered thereby;
          about 17% are treated twice. Exact measurements ensure
          verticality of the casings.
      Placement of Casings
      and  Pattern of
      Overlapping Borings
      Ground-Plan
[ twdiunt Stnd  MB C—,	
 -nxsin        -edxsm
    F'ii:(!!>!i «l high-pressure washing

-------
       Separator Unit
                              Cbart ol the «l»»tion process. The
                            ia puapad on to a vibratory »ieve,
                           °Ve ? ""' "ainly or9anic «*Pon«nt; and
                          ?ravel are "Crated. The paoaing
                la.p""ped lnto tw° hydrocyclones in parallel
               n with a separation limit at about 60 - 80 un.
       ^»n«?    2d^?ludge and Hator Pa"»Bing the double cyclone are
       S3 rS K ,Hlr;C«11? t0 th3mm
                        Bon-Hod
Fig. 5: Flow diagram of separator unit
   Material botween 60 and 120 pa in particle «iz« i« passed
        '                       upotraa'
            theiltr canke? "" deHater1^ sieve where U

   Fresh water and purified water fron the water treatment plant
   is temporarily stored in a water tank fro» where three pumpa
   regulate its usage as HPI-water (18 »»/h), additional flushing
   water within the separator unit (17.7 n'/h),  and support wate?
   tor m.iterial extraction from the boring.
                                             the  separtor uni  .


  The whole separator unit,  newly designed by  the Philipp Holz-
  mann AG, is a mobile unit,  completely fitted into a single
  container frame  in  an upright  position, about  10 • in height
Separator Unit
Overview of
Mass Transport
                                                                                                        Freshwater 17,7m3/h
                                          r
                                                                                                                                      fir
                                                                                                                                      Pollutants
Contaminat
40,5 m3/h
13,0 t/h

sd
i
Mixture
•

StptntofWi

' V-S cm/mini
• Velocity ollowwnj
; HPI-Unce
i
'
Purified Sand
5,9 m'/h Pumpuivoiuii
9,0 t/h MassFtow
                                                                                  Fig. 0: Mass tlow through separator unit

-------
01
Ul
   Now  the  water  treatment,  that can well be seen  as  a  cnquciicc ot
   standard steps known from sanitary engineering,  will  be de-
   scribed  in  brief  with emphasis on the special features  tor the
   Bremen gasworks job.

•  Water Treatment Plant

   The  sludqe-water-pollutant mixture reaching  the water treat
   ment plant  is  first led into tlocculation tanks. A screw
   conveyor transports the flocculated sludge into sieve tanks
   lined with  synthetic mats, where dewatering  to  a dry mibstnnce
   content  of  50% takes place.

   In the next stage oily components are skimmed trom the  sludge-
   free water  usinq buoyancy effects. A storage tank  collects
   the  tar  oils.

   The  oil-free water then passes an activated  carbon filter,
   where polar substances and remaining suspended  particles are
   adsorbed.

   The  last treatment stage is a cyanide flocculation.

   Potable  water  leaves the water treatment plant  into  a storage
   tank from where re-use is directed by pumps.  Excess  water is
   returned to the ground via injection wells.

   Our  partner Umweltschutz Nord has designed and 'operates the
   water treatment plant as well as the final sludge  treatment
   to be described next.

•  Sludge Treatment

   Sludge separated in the water treatment procedure  and conta-
   minated  by-products of the separation are treated  off site
   microbiologically in composting piles where  specially adapted
   bacteria and substratum are added to optimise the  decomposition
   of the polluted sludge. Within six months the PAC-contents have
   been reduced by 90 to 98%.

4.3 Overview of the Holzmann In Situ Soil Purification

    The described complete cleaning process makes  it  pos.sible,
    that no contaminated material has to be deposited nu hazar
    dous waste.

    For the Bremen gasworks site the described  purification
    process results in a plant arrangement shown in Fig. 7.
    Fig. 8  summarises the purification and treatment  steps and
    shows their relationships in the whole process. •
                                                                                       Plan View of Site
                                                                                                                                            j   L
                                                                                                   Supervision.  *••'•	' Bfl H
                                                                                                   Laboratory.'    IHA .1L-A •
                                                                                                   Site Cimp
                                                                                                            Process
                                                                                                    SludgeTank  WileiTir*
                                                                                                             ' ' HPI-Pump
                                                                                              TnkfM
                                                                                              Contaminated
                                                                                              Wiler

                                                                                              Purified Sand
                                                                                         Fig.V: plant  arrangement on site
                                                                                         Holzmann-System of In Situ Soil Purification
                                                                                                                      Placement ot Casing
                                                                                                          First Purification Step by High-Pressure injection and Flushing In Silu
                                                                                                                  Pumping of Soil. Water, and Pollutants
Separation of Grain Size >3 mm and Organic Material:
.Vibratory Sieve
Separation ot Grain Size 60um -3 mm from Fluid Phase:
Hydrocyclones
Flushing of Sand with Freshwater:
Up-Stream Classifier
Dewatering ot Sand (0,1 -3.0 mm):
Dewatering Sieve
*
Exchange of Water within Casing
Replacement ot Sand
Removing of Casing
—

Floccuialion.
Separation,
and Dewatering
of Sludge
Skimming of Oil
Filtration with
Activated Carbon
Floccuialion
of Cyanides
                                                                                                          )l flu?  llolznvinn -Bv.'itoin of in r.ilu
                                                                                                                                                  purification

-------
     b.     Purification Kcnulto

           In the pilot phase of  the  project a detailed liitiil and
           laboratory tooting progranra  van  carried out by an
           dent aupervinnr and the Holzmann  Environnont.il l.ali.

           Individual soil colimno  (borinqs)  were tcalcil Imliini ami
           after purification treatment.

           Typical purification results  tor  optimum action ol  tho
           pilot treatment plant  lay  between 98%  and 991 reduction nl
           the degree of contamination lor PAC. Planned variations ol
           the test  boundary condition!! and  occasional  raallunrtIOIIH
           reduced the overall avcraqe reduction!: a:i nhown in  Kitj. 9.

           The relative degree.of purification is nearly independent
           of  the content of pollutants both  for  the accumulated
           content of 16 PAC and a sun value  for  cyaniden.

           Firnt result!; ot the Main purification contract,  uiiii.-r
           operation since Hay 1989, are very encouraging.  Even tor
           the most  critically contaminated soil  portions  with up to
           20000 rag  PAC/kg dry soil it is most probable  that the
           guaranteed target value of less than 30 mg PAC/kq will be
           reached.  As  average value of the first  30 borings in a
           heavily contaminated soil portion approximately  5 to
           10  rag/kg  dry  soil were measured after  purification.
                                                                                     6.
                                                                                           Uuniiary  and  Aspects ot Application of Holzmann In Situ


                                                                                           Die soil purification plant in Bremen is designed for a
                                                                                           capacity of  6 m'  soil per hour. Soil extraction from tho
                                                                                           tjround lien  on  the critical path. With  the  separator unit
                                                                                           about 9 n'/h soil  can be treated if the input  is continuous.
                                                                                           H.r the extraction and purification of 1 ton of soil about
                                                                                           J.,2 H* process  water are used, most of which is partly
                                                                                           cleaned water circulating in an inner course.  The specific
                                                                                           enerqy demand is about 50 kHh/»'. Up.to 80% of it are
                                                                                           rtiiiuircd by  the high-pressure washing.

                                                                                           l-'or I he purification of  the Bremen gasworks soil  the Holz-
                                                                                           mami in situ purification comprises a number of advantageous
                                                                                           properties that were already expressed in the  comparison of
                                                                                           different approaches in  Fig.  2.

                                                                                           ll.iHcsvor the method aluo  has leas  obvious features  that make
                                                                                           it most flexible tor a variety of  contamination problems
                                                                                           .iricl Hiiperior to other  methods  where high degrees of  complex
                                                                                           contaminations,  narrow site conditions,  and necessity for
                                                                                           restoration of original  soil properties  cone together. Fig.
                                                                                           10 summarises the genuine  advantages  of  the Holznann  In
                                                                                           Situ Soil Purification and  gives  hints  towards  future
                                                                                           supplementations even widening the  outlined range of  appli-
                                                                                           cation.
en
er>
Results and Test Data of In Situ Soil Purification
Average values of degree of purification for RAC and Cyanides

I PAC before
treatment
(mo/kg wen
60-200
200-2000
2000-14000
Average
TugMvtlwIor
puffictttonrfiurl:
Dutch refrain vilu* A:
Dutch ra(innc*nIu«B:
Dutch raliranc* nlu> C:
Av«f»88 hMay1989:
Pilot Phu* 1988
Degree ol
purification
1,
96.0
96,3
96,3
96,2

10-30
0.1
20
200
9.6
ICN Delate
treatment
Img/ttgwel)
40-200
200-600

Average


5
50
500

Di^woi
punhciitioti
"-,.
86.2
93.6

89.9

(rug/kg well
(mg/kg dry)
(mo/kg dryl
(moykgdryj
Img/kgdry)
Advantages of Holzmann In Situ Soil Purification
                                                                                               Trm In iitu todtnlqui (MpvaUon a Kit and polluUnt In atal)
                                                                                               Mum 01 porMtd origlnu toll In titu

                                                                                               SlmunmtomjrounAwiwpurtiicttton
                                                                                               Whofc Mpwuor unl| In • ttigl* conttliw franw
                                                                                               Nodlil«)t«lw^to^-^i I purification
                                                                                         r i
                                                                                           u.lO Advnntaqos of Holzmann  in  situ soil  purification  technique

-------
            BIOLOGICAL REGENERATION OF CONTAMINATED SOIL
Volker Schulz-Berendt
Umweltschutz Nord GmbH & Co
West-Germany
1. Introduction

The clean-up of contaminated sites is a matter  of topical  interest
in the area of environmental conservation. Not  only as  a  result  of
the shut down of industrial plants, such  as  refineries, service
stations and terminals, but also due to accidental  spills it is
becoming ever more important to find an environmentally-  and econo-
mically reasonable method for the clean-up of contaminated soil.

The disposal of contaminated soil on dumps can  be considered only
as temporary solution to the problem.

The biological regeneration is considered to be the better alterna-
tive to special waste land disposal for volumes from some hundreds
up to several thousand cubicmeters. This  process should be pre-
ferred in cases where suitable areas in the  immediate vicinity of
the contaminated site or in its neighbourhood are available and
hydraulic clean-up methods cannot be applied for technical reasons
e. g. very  low permeability of the soil.

Since the biological degradation of organic  compounds leads to a
valuable product which can fulfill its  functions as soil  again,
this is an  ecological valuable method for the clean-up of contami-
nated sites.

The bioremediation of contaminated soil  by microbiological degra-
dation depends on the ability of bacteria and fungi to utilize
contaminants  as  sources of energy  and nutrients. It has been well
documented  that  nearly all organic toxins can be broken down to
harmless  substances  by microbes.

Large scale implementation of microbial  cleaning techniques has
been extremely successful  in the treatment  of mineral oil spills.
Further  successes.have been observed  in the  microbial degradation
of aromatic and  chlorinated hydrocarbons and polycylic hydrocar-
bons.
                                157
                Bergedorfer StraBe 49 • 2875 Ganderkesee 1 • Telefon (04222) 010 22-10 27 • Telefax (04222) 25 03

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 2. Approach

 The biological degradation-process depends on two requirements:

       1. The presence of microbes with appropriate metabolic
          potentials.                                              i

       2. Suitable conditions for microbial life and activity in
          the soil.

 On-site and off-site microbial  soil regeneration by the TERRAFERM
 intensified degradation method is designed to realize these assump-
 tions.

 Before  the beginning of any soil  reclamation the ground is analyzed
 for contaminant contents,  nutrient levels and soil structure. Next,
 the enzymatic turnover potential, the actual microbial activity ariid
 the microbial colonization are calculated into a microbiological
 diagnosis. Based on  these  results, the most appropriate optimiza-
 tion program for maximal contaminant degradation can be selected
 and installed.  Simultaneously,  microbes specially adapted to conta-
 minants are isolated from  the soil, carefully examined for suita- <
 bility,  and used as  appropriate in the optimization process.      j

 The sorted and  classified  soil  is then subjected to extensive pre-'
 paratory procedures.  Large stones and cement blocks are crushed.  !
 Organic substrates are added to improve the soil structure.  Mineral
 nutrients and trace  elements are  added to support the microbial    |
 population.  Finally,  the soil  is  cultured with the adapted bacteria
 and fungi  under conditions of intensive oxygenation.               !

 Oxygen  is introduced  to the system through intensive soil  aeration.

 In  special  cases  anoxygenic conditions are needed for maximum de- i
 gradation or oxygen carriers like nitrate or hydrogen-peroxide
 can  be  added.

 The  biological  breakdown of toxins takes  place in a  totally  en-
 closed dynamic  fermentation  system,  in which  all  parameters,  such
 as  temperature, oxygen  content, nutrient  levels  and  microbial  popu-
 lations  can  be  maintained  at their optimum levels.  Volatile  pollu-
 tants are  contained under  a  specially designed air-discharge bio-
 filter.  Leaching water  is  avoided through careful  controls and by
 preventing rain water from entering  the system.  Thus,  the  conta-
minants  do not  escape to the environment.
                             158
               Bergedorfer StraBe 49 • 2875 Ganderkesee 1 • Telefon (04222) 010 22 -10 27 • Telefax (04222) 25 03

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3. Results

Some of the degradation results are shown  in  the  added  charts.
Hydrocarbons are degraded within 4 to 8 months, depending  on  the
type and amount of mineral hydrocarbon pollutants. The  residual
concentrations lie within naturally occuring  ranges.

Other contaminants like Polychlorinated Biphenyls (PCB's)
need special conditions for optimum degradation.  We  found  that  com-
plete breakdown of chlorinated compounds only take place  if anoxy-
genic steps are involved (see graph).

To guarantee these conditions a soil-fermenter with  a filling-
volume of 200 cubicmeters was constructed  to  adjust  the oxygen-
level of the soil exactly.

After regeneration the cleaned soil is testet vigorously  chemically
and biologically. Aside from measurements  of  contamination, other
characteristics are measured, such as particle size, humus content,
water content potential, soil flora and fauna (as well  as  the
ability to support higher plant life), the absence of weeds,  and
its hygienic suitability for an appropriate future application.

The entire process, from collection of the contaminated soil  to
delivery of the cleaned soil is under constant biological  and
chemical supervision. This assures that dangerous residues are  not
forgotten, and that the prescribed limits  are not surpassed.
                               159
               Bergedorfer StraBe 49 • 2875 Ganderkesee 1 • Telefon (04222) 010 22 -10 27 • Telefax (04222) 25 03

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            S8888-r
            48888

            35888 -F'

            3888a|
    ppa
hydrocarbons  25888 -'•
 (dry basis)
            28888 -f
    large!
    voluo'
                peak   8
              values
                                          TERRAFERM BIOSYSTEM-SOIL
                                             Degradation of hydrocarbons
old
contamination
                                   PCB
                       Degradation Optimization
Sum
if.-
la-

s'
6-
4-


R-
£
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, 	 4 	
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. *•'



. 	 L, 	 1 	 1 	 1 	
1
— +-"''
'"*..
~^—^

PCB-Hix
Standards Nr.
28,52,181,
138, 153, 188
j — i — i — i_i._| ...i
5 18
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*'*--X-*"""
V. *S_
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                               Time (days)
                    Bergedorfer StraBe 49 • 2875 Ganderkesee 1 • Telefon (04222) 010 22 -10 27 • Telefax (04222) 25 03
                                      160                                     :

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   Ecotechniek
                  SEVEN YEARS EXPERIENCE
                 IN THERMAL SOIL TREATMENT
                     Rudolf C.  Reintjes
                        Gees Schuler

                      Ecotechniek bv,
                  Utrecht,  The  Netherlands
Forum on Innovative Hazardous Waste Treatment Technologies:
                 Domestic and International

                         June 1989
                      Atlanta/ Georgia
                               161

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     Ecotechniek
                      SEVEN YEARS EXPERIENCE
                     IN THERMAL SOIL TREATMENT
1.
INTRODUCTION
      Ten years ago, the word soil contamination was not yet  known
      in the Netherlands.  There were of course  some  stories about
      dump sites in the United  States,  but that was far away for
      us. Suddenly,  the existence  of chemical  wastes beneath
      dwellings was reported.  But  it was thought to be  a  single
      and exceptional  case,, and with 100 million dollars the  whole
      problem could be disposed of.  However,  within a short  time
      the number of reported cases  of contaminated  soil in  the
      Netherlands,  had already risen to  one case every 6 km2.
                                                          i
      As  one  of   the  main  companies  in  Holland   in  civiil
      constructions and particularly in  road  construction; Royal
      Volker Stevin has been endeavouring since 1979 to solve this
      problem not                                         i
      only in theory,  but also in practice, and, in practice  means
                                                          I
      for us, amongst  other things, in such a way  that the costs
      can be justified. For  this purpose  a special firm with the
      name Ecotechniek was founded. In  1981 the first pla'nt  for
      soil cleaning was  put  into  operation,  and  since  1986   a
      second plant  has  been providing  service. In the near  future,
      several of these  plants will  be  used in  Europe.      ,
                             162

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     Ecotechniek                   ^
     &
2.    REQUIREMENTS FOR A DECONTAMINATION PLANT

      What conditions had to be fullfilled?
      In most  cases  several contaminating substances  are  present
      besides each other. Therefore  a cleaning technique must  be
      universal.
      The degree of cleaning must be  such that the decontaminated
      soil can be re-used without restrictions.
      A cleaning operation should not take too much time.
      An output of 25-50 tonnes an hour is therefore necessary.
      No new  problems  must  be caused. This means  therefore that
      residues are to be avoided.

      We needed two years for the development of a process  and the
      construction of  an appropriate plant.  In ,the following seven
      years we gathered  a good deal of experience, and realised an
      enormous  number  of  improvements.   During   this period
      decontamination  of 600,000  tonnes of contaminated soil  has
      been carried out.
       PROCES  DESCRIPTION

       Background  and concept of the system  can  be explained with
       reference to  the  schematic drawings  of figure  1  and 2.
       Contaminated  soil  as  a  rule  has a low  organic material
       content,  on avarage about 1  per  cent.  Therefore contaminated
       soil cannot  be cleaned  economically in a normal plant  for
       incineration  of chemical waste. A  new concept  for  thermal
       treatment had to  be developed. We  opted  for a two-phase
       system. During the first phase (figure 1), the  contamination
       is converted into  gases  by heating  the soil,  if necessary  up
       to 550°C.
                               163

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 Ecotechniek
          Phase I
          soil+contaminants
                                evaporated
                                contaminants
                               decontaminated soil
                        Figure  1                   :

 The  developed  vapours are separated from the soil, so that
 the  soil  left  behind, is  clean again. This soil  i$  cooled
 down with water  and  can then be  re-used  normally,  for
 example in the site where it came from.
          Phase II
         gaseous
         contaminants
    clean flue
 7\ gases
\/
     energy
                       Figure 2
During  the  second phase/ the  gaseous  contamination is
destroyed (figure  2).  Therefore  an afterburning kiln is
used. The gases and vapours are burnt with additional oxygen
at  a temperature  of 900°C to 1100°C, or  at  even higher
•temperatures if necessary.  The destroyed  vapours  are freed
from dust and passed into the stack. In the kiln, of course,
a large amount of heat is generated.  This heat is utilised
for  the  evaporation of moisture and contaminants
first phase.

                       164
                      in  the

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     Ecotechniek
     &
      The following scheme therefore arises.
                                           oxygen     energy
                energy

                contaminated
                soil
cleaned soil
                                       cleaned flue gases+
                                       residual energy
                                Figure 3
      It will be clear  to  you that the  special technique  lies  in
      the evaporator, which is designed like  a rotary kiln partly
      with direct firing and  partly with indirect heating  by  means
      of the  flue  gases of the  afterburner,  and, of course in the
      combination of the various parts of  the total plant.

4.    COMPARISON WITH OTHER SYSTEMS

      As stated, all poisonous,  evaporable organic content of the
      soil  is disposed of, regardless of  its chemical  structure,
      quantity  and physical  state.  All types  of  soil  can  be
      processed, although  processing  is  not always equally easy.

      The fact  that  the chemical composition,  concentration and
      type  of  soil  don't  need  to be taken  into  consideration
      distinguishes  this  process  for  example  in comparison  with
      the biological process. The various washing  methods are very
      sensitive to fine fractions of  the soil.
      The thermal  method,  on the other hand,  does not eliminate
      heavy  metals and other  inorganic  substances,  although the
      widespread inorganic cyanide can  nevertheless be eliminated
      very well.
                                 165

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Ecotechniek
       DIFFERENT CATEGORIES OF CONTAMINATES
 heavy tetals
 non volatile
 chlorinated
 organic
 substances
 volatile
 chlorinated
 organic
 substances
cyanides
                       alifatic and
                       aroiatlc
                       hydrocarbons
polycycllc aroiatlc
hydrocarbons
                                   Figure 4
So,  a  thermal cleaning  method does not  solve every  problem,

but  the majority  of them as you can  read from the diagram  in

figure 4 which  describes the distribution of  substances in

polluted soils  in the  Netherlands.  At  least  70 %  can  be

treated thermally.  With -respect  to  thermal methods other

than the one described in this paper, it must be stated that

most of them use  a higher,  or  even much higher,  soil

temperature.  As a  result,   a  lot  of energy  is consumed

unnecessarily,  and the  normal organic substances peculiar to

the  soil,  such as humic acids,  are destructed too.

Hence  the  soil  is not  soil  any more,  but organic  free sand

which  is hardly of interest  for re-use purposes.

Due  to integrated  technology, the  plant  is  very  small  in

relation to its throughput.  This  allows the construction of

semi-mobile machines with a  high  capacity, an  advantage  over

other  systems.
                          166

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     Ecotechniek
5.
CLEANING RESULTS
      It  is  clear  that  for  low-boiling  substances,  only  low
      evaporation  temperatures  are required.  Table I  shows the
      required temperatures.

      In practice,  slightly higher  temperatures are used. In this
      table,  the  required  temperatures in  the  afterburner  are
      listed  too.
                Table
required temperature
contaminant ^^"">"""—— ^^^
petrol, diesel oil
benzene, toluene, xylene,
naphthalene ,
polycyclic aromatic
compounds
cyanides
evaporation
oC
200-300
200-300
450-500
450
destruction
oC
750
-S.
800, .
850
950
      Indicative for the cleaning performance  of the  system are
      the  residual  concentrations  of PAH's  because  they  are
      difficult  to  eliminate  and   the  required   residual
      concentration is low.
      As can be seen  from  figure 5  residual concentrations  could
      be reduced in time due to growing experiences in time.
                               167

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10000
1000
1 100
jl 1008
t f 1IX>
10
1
t ,


H
1
DECONTAM
polyar
L_J_
INATIC
omatic
xnlamin
)NRE,
hydroc
oedtoa
SULT5
arbon
> OF ETTS
s
• fka up B 1 2000 me*fl
mlntnlot
ifler decontamination
Innft a itlutt
otXUnK)
I. t^:
! I
H
j
r j
1
1 8 ttindvd — — — —
f — K
•»• — Aiund»rt— —
fM, 1IW IMS 18W 1M6 1M9 1M9 1889
                                                              Figure 5
  Residual  concentrations can  be reduced  to more  or less  the
  level  of  natural  soil  (the  Dutch  A-level),   although
  pollution degrees  of processed soils are  much higher than  at
  the beginning.

  In figure 6 numbers  are  given for  cyanides,  a  rather often
  occuring  pollutant in the Netherlands, an  inorganic  and very
  stable substance as you know.
  It seems  that  the  realised  resulting  concentrations  for
  cyanides  have  grown through  the years,  but have a look  at
  the concentrations which  are  processed.
Konlnklljke
Voivei-stevln
                 MOO
                 1000
              fi
              If
                 100
soo
                  so
                          DECONTAMINATION RESULTS OF ETTS
                                   cyanides
                              contaminated soil
             after decontamination
              yur
              (RfKI
                      IMS
                           1IN
                                 1M7
                            168
                                nng«o
-------
      I must point  out  that the  residual  concentrations can  be
      reduced as much as  you want,  but that the price to be payed
      for that rises more and more rapidly.

      PCB' s  and  dioxins  have  not been mentioned  up till  now.
      Contamination with these substances  is not widely spread in
      the Netherlands.
      It is  therefore  only recently  that  experiments  on  the
      decontamination of  soils containing these substances have
      been started. No problems are to be expected with PCB anyway.
      The boiling points are low, and destruction is fairly easy.
      The residual concentrations to be obtained are around 1  ppm,
      and therefore fairly  easy.  It  is just a  matter of gathering
      results of tests and  take  additional  safety  measures  during
      execution.

      Dioxins have  to be  reduced to  significantly lower residual
      concentrations and the destruction temperatures  are  higher,
      as you  know.  In four  months time,  tests will be finished
      with which  it will  be  proved  that  dioxin  cleaning  is
      possible with this system.
6.
EMISSIONS
      As already mentioned at  the  beginning,  the process must not
      lead to any pollution  of the environment.  The  only things
      which are released are  flue  gases.  These must  therefore be
      freed from dust,  SC>2,  HC1 and HF (if any present).

      In particular S02 and  HC1  may be released if  sulphur   and
      chlorine containing contaminants are  present.  Depending on
      the requirements set with  respect  to  the contaminants  to be
      eliminated and  depending  on the  local  regulations on
      emissions, a flue gas  cleaning system is selected.
      This means therefore that the plants which  are in operation
      and those which  are currently being built all  have  different
      flue gas cleaning systems. The  concentrations  of substances
      in the  gascleaner  effluent are that low that  the effluent
      can be used to cool the  decontaminated  soil.  So the system
      has vertually no residual waste streams.
     &
                              169

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7.
PLANTS
      Ecotechniek operates,  as  stated,  two  plants,  and a> third one
      is under .construction  that  will be in operation  in Germany
     .within a few  months. The  illustration below will give you an
      impression of the process.                         '
                           THERMAL TREATMENT PLANT E.T.T.S
     The  soil is sieved and crushed  in  a  preparatory line, to a
     material size of  less  than 40  mm.  Then it  is  partially
     heated  indirectly in a rotary kiln. This indirect heating is
     done  with the hot  gases  of the  afterburner.  The soil  is
     heated  further directly by an oil or gas burner. The cleaned
     soil  is led  into  a mixer  and  cooled and moistened  with
     water.  The gases from the kiln are passed to an afterburner,
     in  which  fresh  air  and  energy are  supplied.   Special
     attention  is  given to energy recovery from the flue; gases of
     the  afterburner.  The plant  has three  energy  recovery
     systems, including  the rotary kiln.                 ;
     Furthermore three  dust  collectors are incorporated, one  of
     which works by a wet process which  regulates the pH value of
     the gases before they leave the  stack.
    &
    KV,o[rH!!Vr.                    1 7H
                             1 / U                          ;

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8.     COSTS

      It  is  rather  difficult  to  estimate  the  costs  of
      decontamination of  soil with  this  process in  the  United
      States of America.,
      The costs are  not only  caused  by the process  itself  but  also
      to  a  large  extend by the  moisture content  and pollutant
      content  and  by  safety measurements  and environmental
      regulations.
      Moreover we  cannot  transform our  prices simple by  exchange
      rates.
      So  we can give only a very  rough  indication.  We  think that
      the  processing of  contaminated soil  in the  United  States
      with  this  system will not cost more  than  $  200/ton of  wet
      soil.
                                 171

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                                 AN OGOEN COMPANY
OGDEN
ENVIRONMENTAL SERVICES,  INC,
    CONTAMINATED SOIL REMEDIATION BY

      CIRCULATING BED COMBUSTION
                   BY


            ROBERT G. WILBOURN
            BRENDA M. ANDERSON
         This is a preprint of a paper to be
       presented at the EPA Forum on Innovative
       Hazardous Waste Treatment Technologies.
                 MAY 1989
                  172

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                                   ABSTRACT
     The  Circulating  Bed  Combustor  (CBC)  is an  advanced  generation  of
incinerator that utilizes high velocity air to entrain  circulating  solids  in  a
highly turbulent combustion loop.   Because of its high  thermal  efficiency, the
CBC is ideally suited to treat organic wastes with  low  heat  content,  including
contaminated soil.  This paper discusses the development of CBC  contaminated
soils treatment technology  and  its application to site remediation.  The  CBC
process, pilot plant, and  transportable field equipment units  are  described.
In March of  1989,  a  Superfund  Innovative  Technology Evaluation  (SITE)
demonstration test burn of  McColl Superfund site soil was conducted  in Ogden
Environmental Services'  (OES)  Circulating Bed Combustion  research facility.
The results  of  the successful test are presented  herein.   The paper also
reviews the on-going site remediation activities in Alaska and California using
OES designed, fabricated and deployed transportable CBC units.
                                    173

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 CBC PROCESS  DESCRIPTION

     The  CBC is ideally suited to treat feeds with low heat content,  including
 contaminated soil.   Figure  1  shows  the major components  of a CBC configured for
 soil treatment.  Soil is introduced  into  the combustor  loop at the loop seal
 where  it  immediately contacts  hot  recirculating soil from the hot cyclone.
 Hazardous materials  adhering  to the  introduced feed soil  are rapidly heated and
 continue  to  be exposed  to high temperatures throughout their residence time in
 the ceramic  lined combustor loop.  High velocity air  (14  to 20  ft/s)  entrains
 the feed  with circulating soil which travels upward through the combustor into
 the cyclone.   Retention times in the combustor range from 2 seconds  for  gases
 to  ~30 minutes  for larger feed  materials «1.0 in.).  The  cyclone separates  the
 combustion gases  from the hot  solids, which return to the combustion chamber
 through a proprietary,  non-mechanical seal.   Hot flue gases  and fly ash that
 are separated  at  the cyclone  pass through a convective gas  cooler and on to a
 baghouse  filter which removes the fly ash.  Filtered  flue gas then  exhausts to
 the atmosphere.   Heavier particles  of purified soil  remaining in the lower  bed
 of  the  combustor  are removed  at a controlled  rate by an  ash conveyor system.
 As  a consequence  of the high turbulence in  the combustion zone, temperatures
 around  the loop (combustion chamber, hot  cyclone, return  leg)  are uniform  to
 within +50°F  over the typical operating range of 1450 to  1800°F.  The uniform
 low temperatures  and high solids turbulence  also help avoid the ash flagging
 that is generally encountered in other types of incinerators.         i
                                                                      i
     Acid gases formed during destruction  reactions are rapidly  captured in the
 combustor loop  by limestone that  is  added  directly into  the combustor with  the
 feed.  HC1 and  S02 that  are formed during  the  combustion of chlorine and sulfur
 bearing wastes  react with limestone to form dry calcium chloride and calcium
 sulfate, (benign salts).  Due to the high  combustion efficiency attainable in a
 CBC, an afterburner  is  not  needed.   In more than 90% of the cases studied  to
 date, post-combustor  acid gas scrubbing  is not required.   Emissions  of CO and
NOX  are controlled  to low levels by  the excellent mixing  resulting  from the
turbulence,  by the relatively low temperatures and by staged combustion that is
achieved by injecting secondary air at locations ascending the combustor.
                                     174

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                  COMBUSTION
                  CHAMBER
      LIMESTONE
      FEED
SOLID
FEED
COOLING
WATER
                FLUE GAS
                (DUST)
                FILTER
                                                               STACK
                                                  ASH CONVEYOR
                                                  SYSTEM
    Fig. 1. Schematic Flow Diagram of  Circulating Bed Combustor

                        for Soil Treatment
                                175

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 Because of these design  and  operating features, the CBC  can  attain required
 DREs for both hazardous wastes (ORE 99.99%) and toxic wastes  (DRE 99.9999%) at
 temperatures  below those  used in  conventional  incinerators which typically burn
 at temperatures greater than  2000°F.

      The Circulating Bed  Combustion technology is well developed and  is  being
 applied on two contaminated soil  site  remediation projects that  will clean over
 80,000  tons of contaminated soils.  Ogden  Environmental  Services,  Inc.  (OES)  and
 its predecessors have  pursued a systematic  technology development  and  an
 applications  approach comprised of  the following elements:

        •    Definition of  treatable  soil contaminant wastes  types
        •    Fifteen years  of fluidized  and circulating bed  pilot plant  testing
        •    CBC performance  demonstrations in private and governmental  programs,
            e.g., the  Superfund Innovative Technology Evaluation  (SITE) program
        •    Extensive  permitting activities                         :
        •    Design,  engineering,  fabrication,  deployment,   and operation  of
           modular transportable CBCs  for hazardous waste site cleanups

OES CIRCULATING BED COMBUSTOR UNITS

     Research  Facility

     OES'  research  Circulating Bed Combustor  (CBC)  is the  heart  of an
integrated, highly flexible waste combustion demonstration facility  located  in
San Diego, CA.  Initial CBC-soils treatment development and engineering studies
were carried  out  in the 16-in. (i.d.), 2 million Btu/hr CBC.  The  test  data
obtained were used to design the larger, transportable CBCs.  The configuration
of  the  research CBC  is shown schematically in  Figure  1.   Figure  2  is  a
photograph  of  the 16-in.  CBC unit.   The 16-in. CBC  design  features and
capabilities are summarized in Table 1.                            :
                                     176

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Fig. 2.  16-in. CBC in the San Diego Research  Facility
                          177

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                                        TABLE 1
 Combustor size

   Inside diameter, in.
   Height, ft
                           16"  -  DIAMETER CBC  DESIGN FEATURES
                               AND  EQUIPMENT  CAPACITIES
 16
 27 '-'• •
 Normal operating temperature,  °F

 Maximum outside surface temperature,  °F

 Auxiliary fuel maximum thermal output,
 MMBtu/h

 Soil feeder maximum throughput, Ib/h

 Sorbent feeder maximum throughput,  Ib/h

 Bed ash removal system maximum throughput,
 Ib/h

 Liquid feeder maximum throughput, gpm

 Continuous  on-line  flue gas  analysis
Baghouse filters

  Total surface area, ft2

  Number of filters

  Flow capacity, acfm

  Maximum operating temperature, °F

Forced-draft fan

  Maximum pressure, psig

  Maximum flow, scfm

Induced-draft fan

  Maximum vacuum,  in.  w.g.
 1400 to 1800           ,

 200                    '

 2


 2000

 200

 2500


 30

 0 ico 25% oxygen
 0 to 25% carbon dioxide
 0 to 1000 ppm carbon monoxide
 0 to 1000 ppm nitrogen oxides
 0 to 1000 ppm unburned hydrocarbons
 0 to 1000 ppm sulfur dioxide



 550                   .'...,..

 50

 800

 375                     '.
12

500



50 (at 800 acfm)
                                   178

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     Transportable CBC's             ,

     The transportable 36-in.; (i.d.),  10 million  Btu/hr CBC consists of seven
structural steel modules  that  contain the process equipment  and provide the
structural framework of the CBC.   The modules do not exceed measurements of 8
feet 6 inches wide,  10  feet 4 inches  high,  and 35 feet  long.   As a result,  the
modules can all  be transported on single  drop trailers that  do  not require
special highway  transportation permits.   The CBC cyclone  and combustor are
mounted to  the top  of  one of the  structural modules.    When erected,  the
transportable CBC itself sits on a pad of 30 by 50 feet and is approximately 60
feet in height.   In field operations, the transportable CBC's are incorporated
in  a complete system layout which  includes  ancillary equipment  units and
transportable  buildings,  e.g., a  control  room,  a motor  control center, an
analyzer  room  and a chemistry support  laboratory (optional).  Figure  3  is  a
schematic drawing of the transportable CBC.   Figure 4 is  a  photograph of a
field  assembled  transportable 36-in.  (i.d.) CBC unit.

CBC RATE  THROUGHPUTS

     CBCs have been constructed and  operated with thermal ratings  that  range
 from 2 million Btu/hr to  50 million- Btu/hr.   The  soil throughput of these units
 varies in response  to  the moisture content of the feed  and  to its energetic
 value.  Figure  5  compares the  relative throughputs of several CBC sizes for
 various feed streams.

 MEDIA TREATED

      Circulating Bed Combustion is widely applicable  to many hazardous  waste
 forms.  Solids,  e.g., contaminated soils,  liquids and sludges are  treated with
 equal facility  by  using  the  appropriate feeding systems.   OES has conducted
 extensive pilot  plant and field  unit testing  on soils  contaminated with
 hydrocarbons  and chlorinated hydrocarbons.
                                       179

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Fig. 3.  36" Diameter Transportable CBC Schematic
                       180

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Fig. A.  Field Assembled Transportable CBC Unit
                      181

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LEGEND
•
D
•
O
A
A
WASTE DESCRIPTION
PCB CONTAMINATED SOIL
PCB CONTAMINATED SOIL
CHLORINATED CHEM. SLUDGE
CHLORINATED CHEM. SLUDGE
CHLORINATED LIQUID WASTE
01 LAND SOLVENT WASTE
WATER
CONTENT
%
10
20
80
40
4
13
HEAT
CONTENT
Btu/LB
0
0
1,331
. 4,000
7,606
11,227
THROUGHPUT (LB/HR) VS. COMBUSTER ID.
16 IN.
1,260
930
440
340
210
130
24 IN.
2,840
2,080
1,000
770
470
280
36 IN.
6,380
4,680
2,250
1,740
1,060
740
48 IN.
11,340
8,320
4,000
3,100
1,880
1,140
60 IN.
17,720
13,010
6,250
4,840
2,940
1,780
104 IN.
53,240
39,130
18,770
14,530
8,840
5,340
  100,000
   10.000
=>
O
K
I
    1,000
     100
        10
                                        COMBUSTORIDdN.)
                                                                   100
200
                     Fig.  5.  CBC Unit Size Throughput Comparisons
                                            182

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PROCESS WASTE STREAMS

     The CBC  process typically produces solids  (i.e.,  bed and fly ash)  and
stack gas,  as shown in Figure  1.   The composition  of  the stack-gas  system
effluent must meet  stringent  EPA and  other governmental  requirements  in
accordance with  permitted conditions.   All the  CBC incineration tests  of
contaminated .soils  verify that  the  purified soil  treated by  the CBC  is
non-hazardous with respect to organic residuals.   Since most metals report to
the ash  during combustion,  the disposition of ash  is specific to each waste
feed  case  and must be  determined  on  an  individual basis.   For most
organic-contaminated soil sites, the ash produced by the CBC meets the criteria
for redeposition on  site.  Post-combustion fixation processes  may occasionally
be required  if  the  ash metals  content or  leachability exceeds permissible
levels.

RECENT OES TEST PROGRAMS WITH CONTAMINATED SOIL FEEDS

     Su-perfund Innovative Technology Evaluation (SITE) Program

     In  1986  OES's CBC technology was selected by EPA for a demonstration under
the  SITE program.   Contaminated soil  from the  McColl Superfund site  in
Fullerton, California was  selected as the waste  feed for the demonstration.
Due to multiple delays encountered in the securing all of the required permits,
it was not possible  to conduct the planned feasibility demonstration test until
this year.

     The treatability study  was  conducted  during the week of March 27,  1989  in
the combustion demonstration facility. The study  covered approximately 31 hours
during  a four-day period.   The study was monitored by EPA, the  California
Department of Health Services,  and the San Diego County Air Pollution Control
District.   A test profile is given  in  Figure 6.   A total of 7,500 pounds of
contaminated  soil was processed through the CBC, of which A,700  pounds were
actual  McColl waste. The materials  that were processed  included: unblended
waste, waste  blended with clean sand, and unblended waste "spiked" with carbon
tetrachloride (CCI^).  The materials were  processed  without  difficulty.
Samples  of  the waste feed, fly ash,  bed  ash, and  stack  gas were taken by an EPA
                                      183

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STARTUP/
HEAT UP
THERMAL
EQUILI5RUIM
STABILIZE ON
H<=COLL FEED
SAMPLING
WINPOW
5Y5TEM
IDLE-
I
SYSTE-M
IPLE-
^u
&.
D
cfl
_j

<
h
^
8
(-
D
X
lO
                                                PROTOCOL SAMPLING
                                          \
                                          \
                                           \ 400 L6/HR
                                                          ±j>o
  12   24    36   46   60   72    34
MOKI
TUE
                               THU G.
           Fig. 6. "McColl Treatability Study Test Sequence
                               184

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contractor for extensive analysis.   The  samples  are  being  analyzed for organic
compounds, (including  dioxins and furans), metals,  criteria pollutants, and
physical properties.

     EPA has  officially  released preliminary data which has been checked to
assure that it meets EFA standards  and the complete demonstration test  report
will be  available in August  1989.   The  results show organic material was
effectively destroyed  as exhibited  by the destruction and removal efficiency
(DRE) value  shown in Table  2.   No  significant  levels  of  hazardous organic
compounds left the  CBC system in the stack gas or remained  in the bed  and fly
ash material,  as shown  in  Table 3, which presents  information  on feed and
residuals characteristics.   The criteria pollutant  and acid-gas  release data
obtained meet  federal,  state and South Coast Air Quality  Management  District
(SCAQMD) requirements.   Table 4 contains data on stack criteria pollutant and
acid-gas emissions.  Table  5 presents  stack gas particulate loading data that
are significantly below the  federal requirement of  0.08  grains/dry standard
cubic foot (corrected to 7% oxygen).  The average particulate loading,  however,
is  higher than  the SCAQMD  requirement  of  0.002 grains/dscf.   A Toxicity
Characteristic Leaching  Procedure (TCLP)  test was performed on the McColl CBC
ash.  Arsenic,  selenium, barium, cadmium, chromium,  lead,  mercury and silver
leachabilities were found to  be  low  and meet or  exceed the  federal requirements
(40 CFR Part  268).
     The EPA has concluded the test was successful based on the available
data.
     Transportable CBC Unit  Field Demonstration Test

     OES  conducted a.  PCB-contaminated soil demonstration  test  burn at our
 Swanson River, Alaska  remediation site project in September 1988,  in accordance
 with a  test burn plan prepared by OES and  approved by  the  EPA Office of Toxic
 Substances.   The test  burn was conducted  under witness  of the EPA  and the
 Alaska  Department of Environmental Conservation  (ADEC)  at  the  remote Swanson
 River  Alaska site on  the  Kenai peninsula.   All  required performance criteria
 were met,  and OES has been  granted a nation-wide PCB Disposal Operating Permit
 for its transportable  36-in. (i.d.) CBC  unit.
                                      185

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                        TABLE 2

                   SITE/McCOLL TEST
       DESTRUCTION AND REMOVAL EFFICIENCY  (ORE)
Feed Rate
Stack Emissions

ORE
0.203
0.000017

99.992Z
pounds per hour
pounds per hour
average values using Carbon Tetrachloride
as a performance indicator
                         186'

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                                         TABLE 3

                                    SITE/McCOLL TEST
                            FEED AND RESIDUALS CHARACTERISTICS
                                  Waste Feed
                  Fly Ash
                  Bed Ash
                                                                                 Stack Gas
                                                                                 Emissions
ORGANICS (parts per million)

Benzene
Toluene
Xylene
Ethylbenzene
1,1,1, Trichloroethane
Naphthalene
2-Methyl Naphthalene

PHYSICAL PROPERTIES
     4.9
    35.5
   165.0
    23.0
not detected
    30.2
    34.5
 not  detected
 not  detected
•not  detected
 not  detected
 not  detected
 not  detected
 not  detected
not detected
not detected
not detected
not detected
not detected
not detected
not detected
0.0008
0.0015
0.0015
0.0004
0.0002
0.0006
0.0004
Sulfur (%)
PH
Density
(pounds per cubic foot)
Heat Value
(Btu/ pound)
4.4
2.3
57.9

1387.0

3.6
12.6
76.9

—

0.9
12.1
88.4

- —

—
*™"~
	

— ~

 'not  detected"  indicates  a value below detection limits.

 Organic  feed  and heat values  are based on unblended waste  averages.   All other results are
 based on blended and unblended waste averages.   Waste feed,  fly  ash  and bed ash values are
 weight/weight.  Stack gas emissions  are volume/volume.
                                           187

-------
                                  TABLE 4

                              SITE/McCOLL  TEST
                               AIR EMISSIONS
                    (average values in pounds per hour)
Sulfur Oxides
Nitrogen Oxides
Carbon Monoxide
Total Hydrocarbons
Hydrochloric Acid
(SOX)
(NOX)
(CO)
(THC)
(HC1)
<2.0*
0.34
0.12
0.007
<0.01
 Further quantitation not  possible due to S02 analyzer  insensitivity in
lower range.
                                     188

-------
                               TABLE 5

                           SITE/McCOLL TEST
                         PARTICULATE LOADINGS
                           (average values)

gr/dscf
mg/dscm
Ib/hr
Test Results
0.0038
8.72
Oo0242
Permit Limits
0.08
180.0
not specified
gr/dscf     grains per dry standard cubic feet
            corrected to 7Z oxygen
mg/dscm     milligrams per dry standard cubic meter
                                 189

-------
 USE IN THE U.S.

      The CBC technology has been  recently  applied in large scale at two site
 remediation projects that will treat  over  80,000 tons of  contaminated  soil.
 OES has  proven  the  effectiveness of  transportable  CBCs  by  locating and
 operating them cost-effectively in demanding  environments.  Every regulatory
 requirement for site  operations  has been  met,  and OES  is consistently in
 compliance at  both  sites.  The  transportable CBCs  have  been operated  in weather
 as  cold as -40°F and as high as 110°F.  The ruggedness of  the units  has been
 demonstrated  by mobilizing  and  operating  successfully  in a remote and
 ecologically  sensitive wildlife refuge.   OES  has maintained  high  levels  of
 availability through the use of careful logistics  planning  that includes design
 factors,  maintenance,  and  supply  planning.   A descriptive  summary of OES' two
 major projects is given below.

 PCS SITE  REMEDIATION PROJECT

     The  ARCO  Alaska Swanson River site is located within  the Kenai  Wildlife
 Refuge.   PCS contamination was  identified during site soil  sampling conducted
 by  the  U.S. Fish and  Wildlife  Service  in  1984.   The  contamination was an  '
 indirect  result of  a compressor explosion which  occurred  in 1972.  Remediation
 activities were initiated  by a  voluntary "Order  by Consent" signed by the site
 operator.   The remediation is being  conducted  under the direction of  the U.S.
 Fish  and Wildlife  Service, the Bureau of  Land  Management, and the  Alaska
 Department  of  Environmental  Conservation,  with  the  concurrence  of the U.S.
 Environmental Protection Agency Region X.

     OES was selected  for  the remediation project  because of demonstrated  PCS
destruction capabilities and the CBC combustion technology.   OES'  comprehensive
site  remediation workscope  includes  mobilization,  on-site  demonstration
 testing,  excavation,  contaminated  vegetation  clearing,   incineration,
contaminated water  treatment,  concrete and metal  surface  decontamination,
demobilization, and site restoration.
                                      190

-------
     The completion of  the  Swanson River project is scheduled for  the  end  of
1991.  Upon completion, over  70,000  tons of PCB-contaminated gravel/silt soil
will have been treated.  Figure 7 is a photograph of the Swanson River site.

FUEL OIL SITE REMEDIATION

     For more than 50 years, a leaking underground storage tank at  a cannery in
Stockton, California  contaminated  surrounding clay soil with No. 6 fuel oil.
OES was  contracted by the site operator to remediate  the site using one of  its
transportable  36"-in. (i.d.)  CBCs.   OES  developed and  is  implementing a
remediation plan  that encompasses site  characterization,  demolition of tanks
and  buildings,, installation  and  operation of water  intercept  wells, water
treatment, soil  excavation, stockpiling, CBC treatment, placement  of slurried
purified soil; and site and building restoration.

     The excavation  and backfilling is complete and the CBC thermal  treatment
of stockpiled soils  is approximately  30Z  complete  (June, 1989).  Upon
completion of the project  later in  1989, over 11,000 tons of contaminated soil
will have  been treated.  Following  restoration, the site will have  its  full
commercial  value restored  and it will be available for  unrestricted  use.
Figure 8 is  an overview photograph of  the Stockton project site.

TREATMENT  COSTS

      OES offers  a comprehensive range  of services  for the disposal  of hazardous
wastes, including  pilot plant testing  services, permit  application  and
 responses  to reviews and comments,  economic  and technical evaluation of waste
 disposal alternatives, engineering  design of CBC  plants  to meet  customers'
 needs and specific waste  characteristics, supply of a  mechanically complete
 commercial CBC unit  and supervision and staff for  operation of  the  unit.

      Site  remediation  costs  are divided  into  three  categories.    The  first
 category includes the  direct  and indirect costs for engineering design, base
 equipment  cost,  materials,  foundation and  installation  labor  to  erect a
                                       191

-------
Fig. 7.  Swanson River Project Site, Aerial Photo
                  (Fall - 1988)
                       192

-------
           WATER
           TAbte
RESERVOIR  LEVEL
           I 101'T
            DEPTH)
                                           INTERIM
                                          ASH STORAGE
                                                                AMP
                                                          PROJECT
                                                          TRAILERS
                                                                         UNIT
                                                                                  C&C-TIS
                                                                                 FEED UNIT
EVCAVATIOKl
                                                                                                    'SITE RECEPTION)
                                                                                                       TRAILER
                                                                                                                   STOCKPILE
                                                                                                                  •SOIL
COPWER S-ITE
OF
HOU3&
                WATER
               FACILITIES
                                  WELL
                                 SYSTEM
                          STORAGE
                           5HEP
                                                              EQUIPMENT
                                                             DECONTAMIN AJIOKI
                                                              FACILITY
•STOCKPILE
6ERM ANP
LINER
\ / ^
V-'
CORNER
5UHP
PUMP5
r
\
\
PIPE TO V
HAKJOLISIG
                                      Fig. 8.  Stockton  Leaking Underground Storage Tank

                                                    Remediation Site Photo

-------
mechanically  complete  CBC.   The second category includes CBC costs consisting
of  labor,  materials, utilities, repair  and  maintenance, and indirect costs.
The third  category  includes  material handling operations including excavation,
feed processing, and ash disposal.

     Costs  for  CBC  soil remediation typically range from $100-$300 per  ton
depending primarily on soil  moisture content and the quantity of wastes to be
processed.

SUMMARY

     OES has  developed CBC waste  treatment  technology  and demonstrated  its
applicability in private  and  government sponsored  programs  including the
Superfund  Innovative  Technology Evaluation  (SITE)  program.   Based on this
systematic  development  and  testing,  modular CBC units  have  been designed,
fabricated  and  deployed.    CBC treatment is being utilized  in two large
remediation projects.  Treating contaminated soil  in a CBC is cost-effective,
highly efficient, and meets  all performance  and  operation criteria established
by regulatory agencies.  The Ogden Corporation, OES' parent company,  has made a
major commitment to  the  site remediation business with  four units soon to be
operating.
                                     194

-------
     Residues from  ;:|
     High Temperature
     Rotary Kilns and
     Their Leachability
*»*:• '.to
HELD AT THE ERA CONFERENCE INiArNlA
        JUNg 19-21,1989     j
            195

-------
          Residues from High-Temperature Rotary Kilns
                     and Their Leachability
                               by

                        Ronald Schlegel

  Held at the EPA Conference in Atlanta (June 19 to 21, 1909)
1.
Motives and Objectives
        The  characteristics  of  the residues  generated by  the
        combustion of  hazardous  waste obviously  vary depending
        on where  in  the plant they were obtained.   The largest
        portion of  solid residues  (roughly 80 %)  are  obtained
        immediately  after  the rotary  kiln below the secondary
        combustion   chamber.     In  high   temperature   systems
        slagging rotary kilns), these  slags have  the appearance
        of black glass, and it seems that  they also possess  the
        poperties  of glass.

        The  remaining  residues   are  discharged;  in  the   form
        either  of boiler  ash,  filter  cakes  or  filter  dust,
        depending  on the individual plant design.

        Since the  largest portion of all residues  are  obtained
        in the  form of  slags,  we  wanted  to  investigate  under
        normal  industrial  operating  conditions   whether  the
        composition  of the slags  allows for normal land  disposal
        or even recycling.

        We have  been  repeatedly approached  in  this   matter,
        particularly .by  American  firms  who are  interested  in
        this    question  given   the   much  tighter   economic
        environment  and the stringent  liability regulations  in
                              196

-------
        the U.S.   The  slag leachability tests were consequently
        carried out by an EPA licensed laboratory.

        The  object  of  these  tests  was  on  the one  hand  to
        investigate  the  composition  and  leachability  of  the
        slags  and  on  the  other  hand   to  obtain  experimental
        results  on  the  material  flow under  different  waste
        composition conditions.
2.
The Plant at Rilnmond (Netherlands)
        The  W+E  rotary  kiln   process   line  of  AVR-Chemie's
        hazardous waste  incineration  plant at Rijnmond  took up
        operation in  1987  and  now handles  about 50,000  mt of
        waste a year.  The  plant consists of a high-temperature
        rotary  kiln,  a  secondary combustion  chamber,  a  steam
        boiler to recover the waste-generated heat and  to cool
        down the  flue gases  prior to  their treatment in  a wet
        flue gas treatment system (Figs.  1 to 3,  Table 1).

        Since its purpose is  to  handle hazardous waste from all
        over the  Netherlands, the plant has  to cope with the
        entire  spectrum  of   hazardous   waste,   ranging   from
        unpacked and  packed waste (200,000  barrels a year) to
        contaminated  soil,   liquid  waste of  any  composition,
        sludges and  clinical wastes.   Moreover,  ARV-Chemie is
        the only plant in the Netherlands licensed to incinerate
        PCB-containing wastes.
        The Tests

        The  tests were  carried  out  in  cooperation with  AVR-
        Chemie  and our  US licensee  Combustion Engineering  in
        September 1988.
                          197

-------
Fig.   4  and  Tables  2  to  5  show  the  sampling  and
measuring  points that  were used  during the  tests and
whose  data were  recorded so  that reliable  energy and
mass balances could be established.

The slag and ash samples were extracted every 15 minutes
and  mixed to  representative samples)  then immediately
packed  and dispatched  to the  US  for  the  leachability
tests.
The  specified  and  analysed  menu  was  fed  four  hours
before the  tests  so that the  plant would have reached a
steady   state   condition  by  the   time   a  series  of
measurements begins.   This precaution ensures moreover
that  the slags and ashes  are  actually generated by the
analysed waste samples.                <

Due  to the  large variety of  waste—particularly solid
waste—the  plant  has to process, we were forced to run
the tests on a trace method basis.   We ensured that the
input  contained a  sufficient  amount  of  the particular
waste material  in which we were interested.  Otherwise,
the   plant  was   operated   under   normal  commercial
conditions.

The  following  test  runs  of  different waste flows were
executed (Table 6):

Test # 1
Without barrels; high organic content:
Apart   from   the  "regular"  contaminants,
mixture contained the following:
           the   waste
Chlorine:
Fluorine:
Sulphur compounds:
335 kg/h
 60 kg/h
 18 kg/h
                        198

-------
Test #  3
High content of inert matter containing  PCB
PCB
14 to 15 kg/h
Test # 4
High me,tal. content  (large number of barrels):
Apart  from  the  "usual"  materials,  the  waste mixture
contained the following:
Heavy metals
Class I"••'•••
(Hg, Cd, Tl)
Class II
(Ag, Co, Ni, Se, Te)
Class III
(As, Pb, Cr, Cu, Mo,
 Zn, Rh, Va, Sn)
Total amount:
     1,887 g/h

     2,352 g/h

    16,364 g/h


    20,603 g/h
During  all  tests, the  plant was operated  under normal
operating conditions and did not deviate from the usual,
commercial operations.   The  operating parameters of all
three test runs are given in Table 7.

The leachability tests were carried out according to the
following three methods :

o   Toxicitv Test (EPA SW 846, Method 1310^
    Water is added to  the  sample and a pH  of  5 . 0  ± 0.2
    is  maintained.     Extraction   Procedure   Toxicity
    (EP-TOX) analytes are given in Table 8.
    Toxicity Characteristics Leaching Procedure
    In contrast to the EP-TOX test,  a special extraction
    fluid is used.  The maximum allowable concentrations
    are shown in Table 9 .
                  199

-------
            Total Extractable Metals
            Here, the metals are solved by acids and analysed by
            means of argon plasma spectroscopy.
4.      Results  (Figs. 5.1 to 6.3)

4.1     Material flow

        The consideration of all tests revealed that 90 % of the
        solids input volume  is  discharged in the form of slags,
        whereas only 10 % verge into other output flows.

        Analyses of  individual heavy  metal flows in  the plant
        revealed a  number of interesting  results,  though there
        is obviously nothing  new  to be said about mercury; 92 %
        was determined in the  scrubber  (scrubbing  liquid)  and
        7.2 % in the flue gas.

        Much  more  interesting  are the  cadmium  analyses  since
        they  revealed  a  total output  that was about  3.7  times
        higher than the measured input.  These tests proved once
        again that the major part of all cadmium in the waste is
        not present in its pure form, but in plastics, paints,
        and other materials.

        The analysis   results  showed that  the nickel,  cobalt,
        chromium and copper contained  in  the slag are  mainly of
        a form that does not allow leaching.
4.2
Leachabilitv Tests
        The leachability tests according to the TCLP Method show
        that all values fall short of the threshold limits by at
        least a factor of 100.
                              200

-------
5.
Conclusion

The  TCLP  tests  carried  out the  slag  samples  obtained
from a high  temperature  rotary kiln incineration system
show that the  leachability  of  heavy metals of this slag
is  considerably  lower  than  the  threshold  limits  for
landfill disposal that are in force in the U.S.

The  fact that  all  these  results  were   achieved  with
regular  residues  and  under  normal  commercial  plant
operation   conditions  indicates   that   there  is   a
probability  that this slag  may be  delisted.   Although
any delisting would have to take place on a case to case
basis,  there  are  enormous  potential  advantages.   For
instance, the  sanitary landfill disposal  costs for the
largest  portion of all  residues—up to  80  %—could be
drastically  reduced  and,   even   more  important,   the
potential liability risk  of this  slag is not comparable
to that of hazardous residues.

These  tests  are  obviously just  a beginning;  further
programs  will  be  required  to  build a  data  base on the
disposal  of   slag  obtained  from  these  incineration
systems.  They did,  however,  prove again that the high-
temperature  rotary kiln  technology as applied in Europe
is the  best method of incinerating large amounts of the
entire  range  of  hazardous wastes.    In  Europe,  such
incinerators  have to process  hazardous waste of entire
countries,  or  at  least  vast regions.   Therefore,  they
typically have large capacities of  up to 50,000 mt and
handle  e.g.  55 gallon metal drums, sundry package types
and  other  solid  waaste,  sludges,  slurries,   liquids,
aqueous waste,  etc.

It  is  of course essential that the-residues  leaving the
plant  be not as toxic as the  input and that the volume
be  reduced.   The tests  proved  that these requirements
                          201

-------
6.
were  met,  at  least  for  the  largest  portion  of  these
residues.
Bibliography
        (1)    TCLP    Procedure,    Part    II,    Environmental
               Protection Agency,  40 CPR Part 260 et al.

        (2)    EP-TOX   (Method   C004),    U.S.    Environmental
               Protection   Agency/Office   of    Solid    Waste,
               Washington,  D.C.,  "Test Methods  for  Evaluating
               Solid  Waste-Physical/Chemical   Methods,"  SW-846
               (1980),  Section 7.
                            202

-------
RIJNMOND FACILITY, NETHERLANDS
Fig. 1
ANLAGE RIJNMOND, HOLLAND
                                 203

-------
RIJNMOND FACILITY
Fig. I
ANLAGE RIJNMOND
                               204

-------
903
    Glas fibre reinforced stack
    Might 90m
    Wet scrubber
    Flue gas fan
    Electrostatic precipitator (ESP)
    82,000 NmVh
    Fly ash transport system
    Steam boiler
    Fly ash transport system
    Secondary combustion chamber (SCC)
    Residue discharging	

    Secondary air system	
    Rotary kiln (RK) 	
    Charging hopper for solid waste

    Primary air system	
    Barrel charging	
    approx. 30 barrels/h
    Bunker for solid waste	
    1400m3

-------
                  Table 1
Technical Data of the Plant

Throughput
Heat release
t/h
MW
Mio BTU/h
Steam : Production
Pressure
Temperature
Rotary kiln :
Diameter inside
outside
Length
Secondary combustion
chamber:
t/h
bar
°C

m
m
m

Height (Axis RK to top of SCC) m
Width
Length
m
m
Design
Continuous
load
6.2
23.8
81.2
23.3
30
370

4.2
4.9
12.0

11.6
6.6
6.1
Peak
load
6.8
30.2
103.0
30
30
370








                             W+E Environmental Systems
                206

-------
                                 FEEDWATER
   (T,,
                  ESP
TESTS

Due to the large variety of
waste - particularly solid
waste - the plant has to
process, we were forced to
run the tests on a trace
method basis. We ensured
that the input contained a
sufficient amount of the
particular waste material in
which we were interested.
Otherwise, the plant was
operated under normal
commercial conditions.
PIO)   BOILER
     (CONVECTION PART)
                                                                          0  ©
                                             W+E Environmental Systems
                                 The leachability tests were carried out according to the
                                 following three methods:

                                 O Toxicity Test (EPA SW 846, Method 1310)
                                 OToxicity Characteristics Leaching Procedure (TCLP)
                                 O Total Extractable Metals.
                                                                         W+E Environmental Systems

-------
   SAMPLING £KD MEASURING
                                                                                                                      Table 2.1
                                                                                                                      Date: August 1988
P = Plant Ocoputer / Screen Prints
I WRSTE EEEDINS T _ yest ccoputer - WfE
L = Local / Rack
8 = Screen (hand rec.)
Pt.



1



2






3





4



System
No.


A-251



A-252






A-201





A-202



System



solids feeding



barrels feeding






burner for oil
no. 6 and high
calorific waste



lance for oil
no. 6 and high
calorific waste

Required
Info


weight
number of lifts
heating value
main exposition
weight
number of barrels
feeding time

heating value
content, compo-
sition
flow

temperature

heating value
composition
flow
temperature
heating value
composition
Instrument
Check Point


crane scale
counter
sample analysis
sample analysis
barrel scale
plant computer
plant computer

sample analysis
sample analysis

flow meter no.6/
waste
thermometer

sample analysis
sample analysis
flow meter
thermometer
sample analysis
sample analysis
Instr.
No. /
Resp.

^
-
lab. AVR
lab. AVR
W8350
-
-

lab. AVR
lab. AVR

FI 8001/
8002
TT 8001/
8002
lab. AVR
lab. AVR
FT 8003
TI 8003
lab.
lab.
P
T
L
8
S
S
-
—
P
P
P

—
—

P
P
L
P
—
—
P
P
-
—
Recording /
Sampling


_
-
_
—

_
each diff . type
of barrels
u
_

cont.
cont.
15'
cont.
15 'or cont.

cont.
15'
15 'or cont.
—
Remarks

6: (Screen Prints)
Group no / channel
Crane on manual
operation, ca. 5,0 -
7,5 t/h








G 95/2 + tank level
G 95/3 + tank level

G 00


G 95/4 + tank level
G 00


IN3
O
CO

-------
  SftMPLDG MJD MEASURING
Table 2.2

Date: August 1988
P = Plant Computer / Screen Prints
I waSTE EEEDINS T = Test Computer - WfE
L = Local / Rack
8 = Screen (hand rec.)
Pt.


5



6


7



8





System
NO.


A-203



A-204


A-207



A-206





System


burner for med.
calorifc waste


lance for
pasteous waste

lance for
polymerized
waste

burner SCO for
oil no. 6 and
high calorific
waste


Required
Info


flow
temperature
heating value
composition
flow
temperature
heating value
composition
flow
temperature
heating value
composition
flow

temperature

heating value
composition
Instrument
Check Point


flow meter
thermometer
sample analysis
sample analysis
level difference
thermometer
sample analysis
sample analysis
flow meter
thermometer
sample analysis
sample analysis
flow meter

thermometer

sample analysis
sample analysis
Instr.
No. /
Resp.

FI 8004
TI 8005
lab. AVR
lab. AVR
_
TI 8002
lab. AVR
lab. AVR
EC 8009
TI 8006
lab. AVR
lab. AVR
FE 8005/
8006
TI 8007/
8008
lab. AVR
lab. AVR
P
T
L
S
P
P
—

P
P

P
-
—
"
P
P
L
P
—

Recording /
Sampling


cont.
15'
15'

15'
cont.
15'or cont.

_
—
~

cont.
cont.
15'
cont.
15'or cont.

Remarks
Gt (Screen Prints)
Group no / channel
G 95/5



tank level measurem.
G 00

G 99/5, during test
not in operation


G 95/6 + tank level
G 95/7 + tank level
G 00



ro
o
10

-------
BaMPUNS
MEASURING
                                                                                                   Table 2.3
                                                                                                   Date: August 1988








ro
i— >
<->



_ ___ ,. 	 p = Plant Cccpiter / screen Prints
J. WflSiE J* Kr'l YlNR rn m^.-. i. •• 	 -«
L = Local / Rack
S = screen (hand rec.)
Pt.


9



10


System
No.


A-205A



A-205B


System


lance for low
calorific waste
(waste water)


lance for low
calorific waste
(waste water)

Required
Info


flow
temperature
heating value
composition

flow
temperature
heating value
composition
Instrument
Check Point


flow meter
thermometer
sample analysis
sample analysis

flow meter
thermometer
sample analysis
sample analysis
Instr.
No. /
Resp.

FI 8007
TI 8009
lab.
lab.

FI 8008
TT 8010
—

P
T
L
S
P
P

—

P
P


Recording /
Sampling


cont.
15'or cont.


15 'or cont.
15'

Remarks
G: (Screen Prints)
Group no / channel
G 94/2 + tank level



G 95/1 + tank level



-------
  SAMPLING MID MEASURING
Table 3
Date: August 1988
ro.
	 	 	 — 	 P - plant Computer / Screen Prints
wnw T = Test Computer - WfE
S - Screen (hand rec.)
Pt.
11
T
12
)
13
14
15
16
System
No.
K-251
K-251
K-255

K-
K-252
K-256
K-
System
primary air
primary air
cooling air

burner air
secondary air
oonding. air
burner air
Required
Info
flow
temperature
flow

flow
flow
flow
flow
Instrument
Check Point
annubar
PT-100
pitot or anemometer

pitot
annubar
pitot
pitot
Instr.
No. /
Resp.
F 8100
T 8102
W-E/AVR

WfE
F 8103
-
WfE
P
T
L
S
P/T
T
L

L
P/T
L
L
Recording /
Sampling
cont.
cont.
1 X

cont.
cont.
1 X
cont.
Remarks
G: (Screen Prints)
Group no / channel
G 94/3

travers measurement
(ca. 2000 m3/h)


G 94/4
travers measurement
(ca. 2000 m3/h)


-------
SAMPLING MJD MEaSURING
                                                                                                                Table 4.1
                                                                                                                Date: August 1988
L = Local / Rack
	 	 	 S = Screen (hand ree.l
Pt.
20
21
22

23

System
No.
A-266
X-250
X-251

X-252

System
slag discharger
boiler ash
radiation part
discharger
boiler ash
conv. part
discharger

ESP-ash

Required
Info
tot. weight
repr. sample
tot. weight
repr. sample
tot. weight
repr. sample

tot. weight
repr. sample
Instrument
Check Point
-
-
-

-

Instr.
No. /
Rfesp.
-
-
-

-

P
T
L
S
-
-
-

-

Recording /
Sampling
15'
cont.
cont.

-
cont.
Remarks
G: (Screen Prints)
Group no / channel
See procedure for slag
sampling
Sample analysis :CE
mixed - representative
sample
Sample analysis :CE
sampled through the
emergency opening with
a special installa-
tion.
- mixed - repr. sample
Sample analysis :CE

Sample analysis :CE

-------
  SAMPLING AND MEASURING
Table 4.2
Date: August 1988
	 	 — — 	 - ~~ ~ p = Plant Computer / Screen Prints
III SLAG, ASH AND FLUE GAS T = Jart 0-prtjr - W«
L = Local / Rack
S = Screen (hand rec.)
Pt.

24
(05)




System
No.







System

flue gas to gas
cleaning system



flue gas to
stack
Required
Info

flow
CD-content
HCL
HF
H2O
Dust-content
Heavy metals in
the gas
(^-content
CD-content
S02
CO
Instrument
Check Point

.
Sieroens-^Jltramat
_
_
—
Sick GM 21
Instr.
No. /
Resp.

_
QI 8101
AVR
AVR
AVR
AVR
AVR
AVR
AVR
QI 8205
QI 8208
P
T
L
S
L
P
L
L
L
L
L
L
L
P
Recording /
Sampling

cont.
cent.
cont.
cont.
cont.
cont.
cont.
cont.
cont.
cont.
Remarks
G: (Screen Prints)
; Group no / channel

G 96/2
Analysis: AVR
Analysis: AVR
Analysis: AVR
Analysis: CE
Analysis: CE
Analysis: AVR
Analysis: AVR
G 96/5
IN5
I—»
CO

-------
SAMPLING MJD MEASURING
                                                                                                                Table 5.1
                                                                                                                Date: august 1988
_T P = Plant Ocnpiter / Screen Prints
IV PROCESS AND CONTROL MEASUREMENTS T = Test Computer - Wf E
L = Local / Rack
B = screen (hand rec.)
Pt.



Tl

-T2
T3

T4a
T4b
P4
T5a

Q5

T6
T7
T8
System
No.


F-251

F-251
F-252

F-252
F-252
F-252
H-251

H-251

T-253
T-254
T-255
System



kiln shell

kiln
SCC wall

SCC outlet
SCC outlet
SCC outlet
boiler-radia-
tion-part
outlet
boiler-radia
tion-part
outlet
ash-hopper
ash hopper
ash hopper
Required
Info


wall temperature

slag temperature
wall tenperature

gas tenperature
gas tenperature
gas pressure
gas tenperature

CO Vol-%

gas tenperature
gas tenperature
gas tenperature
Instrument
Check Point


local thermometer

pyrometer
local thermometer

thermo couple
pyrometer
pressure transm.
thermo couple

CO-test

thermometer
thermometer
thermometer
Instr.
No. /
Resp.

T 8091/
94/97
TI 8106
T 8054/
55
TI 8107
TI 8108
PI 8110
TI 8109

QI 8101

T 8073
T -
T -
P
T
L
B
L

P/T
L

T/P
P
P/T
P/T

P/T

L
L
L
Recording /
Sampling


1 X

cont.
1 X

cont.
cont.
cont.
cont.

cont.

30'
30'
30'
Remarks

G: (Screen Prints)
Group no / channel


G 90/1


G 90/2
G 90/3
G 92/3 :
G 90/4

G 96/2





-------
   SAMPLING AND MEASURING
Table 5.2

Date: August 1988
P = Plant Computer / Screen Prints
IV PROCESS AMD CONTROL MEASUREMENTS T = Test Computer - WfE
L = Local / Rack
S = Screen (hand rec.)
Pt.
T10
P10
P20
T20
F20
P23
T23
F2B
Til
-
-
System
No.
T-
T-
-
-
-
-
-
-
-

-
System
boiler outlet
boiler outlet
feed water
feed water
feed water
steam
steam
steam
fuel gas at
ESP outlet
cooling water
cooling air RK
Required
Info
gas temperature
gas pressure
pressure
temperature
flow
pressure
temperature
flow
temperature
flow
temp, difference
flow
Instrument
Check Point
PT-100
pressure transm.
pressure transm.
thermometer
annubar
pressure transm.
thermometer
annubar
PT-100
pump characteristic
thentoneter
anemometer
Instr.
No. /
Resp.
IT 8110
PI 8112
PI 8118
TI 8114
FI 8101
PI 8124
TI 8123
FI 8102
TI 8207
-
-
P
T
L
S
P/T
P
T
P/T
P
T
P
P
T
-
-
Recording /
Sampling
cont.
cont.
pont.
cont.
cont.
cont.
cont.
cont.
cont.
1 X
1 X
1 X
Remarks
G: (Screen Prints)
Group no / channel
G 90/5



G 94/6

G 101/4
G 94/5



ro
i—>
en

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                                                                                                  Hi
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                                                                                                  rt

-------
Flmount •
Cl
120,29
1,50
201,14
12,22
335, 16
C kq/h 3
"F
54,54
0,60
5,32
0,23
60,70
, . p.
- •
_
S
5,84
1,50
8,87
1,75
17,96
Metal inpi
Hg
0,10
17,85
1,51
0,50
19,96
jt C g/h :
Cd
0,49
1,50
2,96
2,04
6,98
1
Tl
-
-
fis
-
-
!Rmount
C kg/h
Meta1 input
C  g/h 3
Cl
2,10
0,71
0,48
44,06
0,92
48,27
F
1 , 05
0,04
0,19
8,42
0,09
9,79
P !
I
.-.
-
S
4,20
0,71
0,48
2,48
2,76
10,63
Hg !
0,63
0,06
0,06
2,65
2,39
5,80
Cd
2,10
0,36
0,48
2,48
0,92
6,33
Tl
,
. -
fls
-
-
flmount
Cl !
1
1,70
4,34
0,55
170,09
44,10
220,77
C kq/h 3
"F !
I
1
0,09
18,94
0,22
3,20
0,63
23,08
P !

--
•
S
1,70
4,34
0,55
17,26
14,70
38,54
Metal inpi.
Hg 1
0,81
1832,08
0,17
2,02
3,86
1838,94
jt. C g/h ]
Cd
0,85
32,54
0,55
2,47
11,55
47,95
Tl
'
~"
-
fls :
-
-
i
i


qas
_i
b
g/h
2,53
1,27
6,18
3,3

Gas-
hum i d i ty
vol-X
9,2
10,9
8,3
9,5
Slag
percent
from
solids
•/.
87,66
92,05
89,54
99,75
I
1
1
I
I
i
I
•
* " - i
i
i
1
I
I
HRZIFIRD GRSES
HC1 tr.
Rawgas-
conc.
calcul.
mg/NmA3
5509,50
823,94
3501,90
:HF tr.
! Rawqas-
! cane .
! ca 1 cu 1 .
i mg/NmA3
! 1021,59
! 171,01
! 374,84
1502 tr.
! Rawqas--
! cone .
! calcul .
! mg/Nn»A3
! 574,43
i 352,95
i 1189,26
I
I i ' i
f I I
                                         217

-------
Co
15,10
Q2,50
283,97
39,58
421,14
Ni
40,42
222,00
760,21
81,48
1104,11
Sb
-
•
Pb
46,27
258,00
854,86
91,37
1250,50.
Cr
4,87
27,00
94,66
9,89
136,42
Cu
4,87
322,50
6321,25
72,17
6720,78
Sn
60,88
331,50
1990,73
122,22
2505,33
8a
-
-
Co
210,00
35,60
48,30
247,50
92,00
633,40
Ni
420,00
35,60
48,30
247,50
92,00
843,40
Sb

-
Pb
420,00
35,60
48,30
247, 50
276,00
1027,40
Cr
210,00
35,60
48,30
247,50
92,00
633,40
.• :•&&
1680,00
35,60
48,30
247,50
828,00
2839,40
Sn
630,00
35,60
48,30
247,50
184,00
1145,40
Ba
-
_
Co
85,00
144,60
55,10
246,50
210,00
741,20
Ni
85,00
144,60
110,20
246,50
210,00
796, 3O
Sb


Pb
85,00
2169,00
110,20
246,50
420,00
3030,70
Cr
85,00
144,60
55, 10
246,50
210,00
741,20
Cu
765,00
144,60
440,80
1232,50
210,00
2792,90
Sn
85,00
144,60
165,30
493,00
210,00
1097,90
Ba


218

-------
flg

65,75
360,00
236,44
132,11
794,30
Ge

4 , 87
15,00
29,58
5,82
55,27
Be
_
-.
-
?n

4,87
27,00
94,66
9,89
136,42
Mo

35,06 .
1 1 1 , 00
381,58
58,78
586,43
input rif
ana 1 ys.ed
heavy
metals
g/h
14737,65
Flg



210,00
35,60
48,30
247,50
92,00
633,40
Se



21,00
3,56
4,83
24,75
9,20
63 .,34
Be



_.
-
--
-
—
_

-------
                         Table 7
I Operating  Data  at Slag Tests
 Measurable
 Variable
           Test 1   Test 3   Test 4
 Temperature rotary kiln
 Temperature secondary
 combustion chamber
 Boiler outlet
 Steam temperature

 Steam pressure
 Steam production
 Volume flow

 Oxygen content
 Gas humidity
      °C
      °C

     bar
      t/h
mVh (N, f)

   % Vol.
   % Vol.
           1255    1290   1260
           1076 '   1250   1100
250
379

 30
 27.9
250
391
250
391
 30      30
 33.5     29.2
 75,200   74,300  76,500
  8.7
  9.2
  6.3
 10.9
  7.5
  8.3
                                      W+E Environmental Systems
                      220

-------
 .  5.1
•£
0)

cB

_§ -O
_Q 3
1 "
1
WH^^H
r




1,8%

t







•>
i
i









«
(0
O)
0)
E










                   48%
0,6%
                            W+E Environmental Systems
221

-------
                                                 Secondary
                                                 combustion chamber
                                                       Slag
ro
ro
          m
          m
          o

          I
          CO
          CD
          3
          CO
                                                 Electrostatic precipitator


                                                     Fly ash
                                                Wet scrubber
                                                    Scrubber effluent
                                                        Secondary
                                                        combustion chamber
                                                             Slag
                                                                                                            Boiler
                                                                                                                 Fly ash
                                                       Electrostatic precipitator


                                                            Fly ash
                                                                                                           Wet scrubber
                                                                                                                Scrubber effluent
Flue gas

-------
                            W+E Environmental Systems
223

-------
ro
ro
           m
           rn
           (D
                                           Rotary kiln
                                                  Secondary
                                                  combustion chamber
                                                                   O

                                                                   I

                                                                   c'
                                                                   3
                                                  Electrostatic precipitator
                                                  Wet scrubber
                                                      Scrubber effluent      &

                "
                p
Secondary
combustion chamber
                                                                                                                                    Stack
                                                                                                                  Flue gas
                                                                                                                                                  UI

-------
                                                                                  0,2%
Copper (Cu)
100%       §.
                                                                                        CO
                                                                                        «J
                                                                                        0)
                                                                                        0)
                                                                                   0,3%
                                                                                        W
                                                                                        (0
                                                                                        D)

                                                                                        (!)


                                                                                        SI
                              3,2%
18%
78%
0,1 %
                                                                      W+E Environmental Systems
                                          225

-------
                         Fig. 6.1
Comparison between the max. admissible heavy metal
concetrations according to TCPL and the concentrations
found in the slag                                       Test 1
      mg/l   Hg    Cd    Se    Pb    Cr    Ag    As   Ba
a
   100
            0.2    1.0     1.0   5.0    5.0    5.0    5.0  100.0
            0.00    0.00    0.00   0.00   0.00   0.00   0.00  0.27
  0.25
  0.5
     mg/l   Hg   Cd    Se    Pb    Cr     Ag    As    Ba
                                                 W+E Environmental Systems
                           226

-------
                             Fig. 6.2
Comparison between the max. admissible heavy metal
concetrations according to TCPL and the concentrations
found in the slag                                       Tests
      mg/l
Ag    As   Ba
T3
(0

X
ro
   100
    25
   0.25
 tl 0.5
             0.2    1.0    1.0    5.0    5.0    5.0    5.0  100.0
             0.00   0.01   0.00   0.06   0.00   O.QO   0.00   0-17















	 •!




• — •• —














•
I
"



t


       mg/l   Hg    Cd     Se    Pb    Cr    Ag    As    Ba
                                                  W+E Environmental Systems
                               227

-------
                               Fig.  6.3
Comparison between the max. admissible heavy metal
concetrations according to TCPL and the concentrations
found in the leaching of the slag                        Test 4
      mg/l    Hg    Cd
                     Se    Pb
Cr
Ag
As   Ba
.

1

•o
ro
x

1
100
  0.25
Q>
  0.5
            0.2    1.0    1.0    5.0   5.0    5.0    5.0  100.0
            0.00   0.01    0.00   0.06   0.00   0.00   0.00  0.16
      mg/l   Hg    Cd     Se    Pb    Cr    Ag    As    Ba



                                                 W+E Environmental Systems
                            228

-------
TRBT3R 8 —
   ANALYTE
MAXIMDM CONCENTRATION
   Arsenic
   Barium
   Cadmium
   Chrcsnium
   Lead
   Mercury
   Selenium
   Silver
   Endrin
   Lindane
   Methoxychlor
   Toxaphene
   2, 4-D
   2,4,5-TP (Silvex)
          5.0
        100.0
          1.0
          5.0
          5.0
          0.2
          1.0
          5.0
         0.02
          0.4
         10.0
          0.5
         10.0
          1.0
                                   229

-------
TOBTJR 9 - IdJP MPVLYTES KND
                                    UTTncnvBTJ!
   ANALYTE
MAXIMUM GONOEOTRATION
        irg/1
   Arsenic
   Barium
   Cadmium
   Chromium
   Lead
   Mercury
   Selenium
   Silver
   Endrin
   Lindane
   Methoxychlor
   Toxaphene
   Heptachlor
   a-Chlordane
   r-Chlordane
   2, 4-D
   2,4,5-TP
   Phenol
   bis (2-Chloroethyl)ether
   1,4-Dichlorobenzene
   1,2-Dichlorobenzene
   2-Methylj*ienol
   4HMethylphenol
   Hexachloroethane
   Nitrobenzene
   Hexachlorobutadiene
   2,4,6-Trichloropherioi
   2,4,5-Trichlorophenol
   3-^fethylphenol
   Fyridine
   2,3,4,6-Tetrachlorophenol
   2,4-Dinitrotoluene
   Hexachlorobenzene
   Fentachlorojiienol
     5.0
   100.0
     1.0
     5.0
     5.0
     0.2
     1.0
     5.0
   0.003
    0.06
     1.4
    0.07
   0.001
    0.03
    0.03
     1.4
     0.1
    14.4
    0.05
    10.8
     4.3
    10.0
    10.0
     4.3
    0.13
    0.72
    0.30
     5.8
    10.0
     5.0
     1.5
    0.13
    0.13
     3.6
   * Volatile organic conpounds were not analyzed.
                              230

-------
                          Recycling of contaminated river and
              lake sediments demonstrated by the example of Neckar sludge
             Dipl.-Ing. M. NuIJbaumer, M.Sc. * and Dipl.-Ing. E. Bellinger
Summary

The Neckar is an approximately 370 km long tributary of the Rhine, its confluence with the
same being not far downstream from Heidelberg. The river was made navigable over a length
of 202 km during the decades following the last World War, i.e. weirs with locks were
constructed at some 20 km intervals along the river to regulate the water-level. Primarily
fine-grained, suspended and sedimentary materials are deposited in the storage ponds and
lead to the necessity of river dredging.

The purposes of the dredging are

           - to  keep the navigation lane open,
           - to  maintain the required river cross-section for flood control and
           - to  maintain water quality.

The dredged material has become contaminated by heavy metals due to the expansion of in-
dustry in the area, cadmium being the prime example. The sometimes high cadmium cont-
amination precludes the use of the dredged materials for agricultural purposes. It was there-
fore initially proposed that the dredged sludge be dried and dumped at waste disposal sites.
Since sites for waste disposal are rare and expensive to put into operation in the  Federal Re-
public, economic means of recycling had to be sought.
* Managing director, Ed. Ziiblin AG, Civil Engineering Contractors, Stuttgart, FRG
0 Senior engineer, Ed. Ziiblin AG, Stuttgart, FRG
                                     231

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Toward this end one of the largest civil engineering contractors in the FRG, Ed. Zublin AG
of Stuttgart, has developed a process whereby dredged material is converted into spherical,
porous, lightweight aggregate for the production of masonry blocks and lightweight concrete.

The above-mentioned company has been awarded a contract to construct and operate a plant
for the thermal treatment of 500,000 m3 of sludge dredged out of the Neckar over a period
of 10 years. In order to enable the thermal procedure involving temperatures of up to
1150 °C to be successfully put into service in an environment-friendly manner, a new con-
cept  for outlet-gas treatment had to be developed and tested.
Contaminated sediments

Dredged sludges from rivers and harbours can no longer be used for agricultural purposes
because of their high level of contamination. The quantity of sludge dredged by the water
and river navigation authorities to maintain navigation lanes is however considerable: in
1982 a total of 48 million cbm  was removed from Federal waterways, of these 11 million
cbm were from the Elbe and 12 million cbm were from the Rhine alone.

During the last two decades some 2 million cbm of sediments have accumilated on the bed of
the Neckar between Plochingen and  Heilbronn. Although extensive measures to improve ef-
fluent quality have reduced heavy metal pollution, the heavy metal content of the sediments
in such that they cannot be used for agricultural purposes.

One cbm of Neckar sediment contains 800 1 water and 550 kg solids. 5 % of the solids are
debris of organic or anthropogenic origin such as woods,  bicycles, refrigerators and rubble.
The major part is, however, of mineral origin and has found its way into the river by way of
natural erosion in the river's catchment area. The material from the  clay and silt fractions up
to 0.063 mm amounts to 40 % by weight of the sediment  on  average, while sand and gravel
between 0.063 and 60 mm also make up 40 % by weight of the sediment. The composition
varies, however, considerably.
                                    232

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High levels of pollutants accumulate in the fine-grained sediments. A number of investig-
ations have demonstrated that a larger quantity of heavy metals accumulates in the fine-
grained fraction of the dredged sludges than in the sand and gravel fractions. The sand-and  .
gravel fractions can therefore be disposed of relatively easily, while the fine-grained sludge
presents a considerable problem.

Of the pollutants, heavy metals, heavy metal compounds, salts and all organic materials
which enter a watercourse as a result of industrial production present a significant problem.
The focal point of the investigations of the dredged Neckar sludge was, however, the reten-
tion of cadmium, which was detected in concentrations of up to 240  mg/kg (dry weight).
The permissible concentration in soil used for agricultural purposes is 3 mg/kg (dry weight).

Up to ten years ago dredged Neckar sludge was used for agricultural purposes in large quan-
tities. A layer of sludge up to 1 m in thickness was spread over existing fields. This soil has
now had to be removed in part due to the high concentrations of  heavy metals. Other pro-
cedures, such as drying in air, mechanical dewatering and hardening with alkaline binding
agents,  require waste disposal sites for end storage. On the Neckar, the dredged material was
to be partially dewatered in three air-drying plants and subsequently transported to three
remote  single-purpose waste disposal sites. The adoption of this approach met with conside-
rable resistance.
Procedure to recycle contaminated sediments

As a result of the above, it was decided to largely avoid dumping Neckar sludge. Instead it
was proposed that spherical, porous, lightweight aggregate be produced from the sludge by
way of adding expanding clay, the aggregate having characteristics similar to expanded clay
and being capable of use as a substitute building  material in order to reduce the import of
expensive pumice-stone.

The procedure involves transporting the dredged sludge to a central treatment plant at which
an intermediate storage facility has been installed to even out seasonal variations in dredging
activity. The sludge is then partially dewatered in a screen belt press (mechanical process)
and mixed with clay and additives.
                                     233

-------
The amount of clay and expanded clay additive amounts to between 15 % and 30 % by
weight depending on the required strength and heat insulation properties of the final pro-
duct. The mixture is subsequently made into pellets and then dried, burnt and cooled in the
actual rotary kiln plant. The temperature of combustion may rise up to 1150 °C. Heat is ex-
tracted from the outlet-gas to be used elsewhere in the system, thus ensuring a high degree
of heat reclamation.
Development for full-scale operation.

The procedure has been developed for full-scale operation with the support of the Bundes-
minister fur Forschung und Technologic (Federal Minister for Research and Technology) and
tested in two stages. The development work was based on the results of innumerable labora-
tory tests to find suitable mixtures for the differing sludge compositions, clay content etc.,
all of which have to ensure sufficiently good product characteristics.
             3*?:-   - /
            dredging
           treatment
           filtration
            water
                                          discharge gas treatment
                                           drying
                     mixing pelleting	combustion  grading
Fig. 1.     [OPERATION SEQUENCE FOR RECYCLING  SLUDGE
                                   234

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The main technical and scientific objective of the research and development programme was
to prove that lightweight aggregate can be produced industrially from fine-grained river and
lake sediments, that the aggregate's physical properties permit a wide range of applications
and that the procedure can be operated economically. The production-of the lightweight ag-
gregate must be favourably priced, sure in operation, environment-friendly and adaptable to
variations in raw material quality.
 Fig. 2.     Pellets of dried Neckar sludge and expanded clay.
 Neckar sludge served as the "raw material", the sludge having been dredged out of the up-
 stream area of locks and demonstrating a wide spectrum with respect to both its grain-size
 distribution and its contamination.
 Pretreatment of the sludge

 The sludge must be dried before it is burnt. The drying is firstly mechanical in screen belt
 presses and then, in pellet-form, in the kiln plant drier. In order to achieve as high a solids
 content as possible before the sludge  is fed into the thermal drying plant, numerous tests
 were caried out with  screen belt presses and flocculation agents.
                                      235

-------
Expanded Clay Production using Neckar Sediments

An industrially-used expanded clay production plant was modified and used to produce ex-
panded clay from Neckar sediments in the first and second test phases.

The mixture-ratios which had been selected during laboratory tests were shown to be suit-
able in the first test phase. The measured outlet-gas values were used as initial values to
design the outlet-gas treatment. The second  test phase was spent optimizing and testing a pi-
lot outlet-gas treatment plant.

The end product  is a lightweight aggregate of various sizes (0-16 mm). The expanded clay
can be used as a building material. It has a high compressive strength, excellent insulation
properties and is  easy to handle.

The expanded clay  was tested with reference to the requirements set out in DIN 4226, Part 2,
for lightweight aggregates. All the requirements were met. The heavy metal content lies in
the same region as is to be found in other building materials such as pumice, brick,
aerated concrete and conventional expanded clay. Numerous tests have proven  that the ex-
panded clay is a suitable building material for walls.
Fig. 3.     Hollow masonry blocks leaving the press.
                                      236

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Hollow masonry and masonry blocks were produced in a cement works. These blocks also
met all the requirements for outer and/or inner insulatory masonry blocks.
 Fig. 4.     Hollow masonry blocks made from Neckar sludge replace valuable raw materials
           and fulfil heat insulation requirements.
 Outlet-Gas Treatment

 There is no visible difference between the above-mentioned end product and expanded clay
 blocks. Waste, in this case contaminated river sludge, has been used to produce a first-class
 block and at the same time the use of valuable raw materials has been minimized.

 Where have all the heavy metals gone?  100.000 m8 of river sediments which are dredged out
 of the Neckar annually contain approximately 500 kg - 1000 kg cadmium. Cadmium has a
 boiling-point of 700 °C which is below the combustion temperature. The outlet-gas treat-
 ment has therefore to ensure that cadmium as well as other heavy metals and contaminants
 present in the outlet-gas are not emitted into the atmosphere.

 The outlet-gas values were measured during the first test phase, analysed and interpreted.
 The areas concentrated on were heavy metals and the acidic gaseous components in the gas
 such as SOX, N0x, HF and HC1.
                                      237

-------
 A treatment process capable of removing all these contaminants was not to be found so that a
 plant had to be designed by the contractors. The Landesanstalt fur Umweltschutz in Karls-
 ruhe (State Environmental Agency) took the outlet-gas measurements during the test phases
 on behalf of the Regierungsprasidium Stuttgart (State Government).

 The outlet-gas treatment was designed in close cooperation with the Landesanstalt fur Um-
 weltschutz in Karlsruhe. The treatment process is in four stages.

 Stage I
 Cyclone and sleeve filters seperate out larger particles. These are returned to the production
 process at the mixing stage.

 Stage II
 A sleeve filter seperates out dust form the belt drier. This dust is also returned to the pro-
 duction process at the mixing stage. The outlet-gas then undergoes secondary combustion at
 temperatures of 800 - 900 °C and a residence time of more than one second. This waste heat
 is then recovered in a heat-exchanger which has an  effectiveness of 75-80 %. The recovered
 heat is used to warm the belt drier.

 Stage III
 Dry absorption (lime dosage) with subsequent sleeve filter.

 Stage IV
 Double fines filter. The dust emitted into the atmosphere after these filters is less than
 0.01 mg/Nms.

 The outlet-gas system is hermetically sealed. Larger  particles with a low contaminant con-
 centration are seperated out of the outlet-gas in the  cyclone. The sleeve filters then clean the
 air further and prevent the heat exchanger and the secondary combustion chamber from
clogging up. Organic compounds are present in the gas released from the mixture whilst in
the combustion kiln. These are turned into carbon dioxide (CO2), water (H2O) and hydro-
fluoric or hydrochloric acid (HF, HC1) in the secondary combustion chamber.
                                      238

-------
The acidic gaseous components present in the gas such as sulpher oxides (SOx), hydrofluoric
and hydrochloric acid (HF, HC1) react with lime (Ca(OH)2) during the dry absorption to
form solid, saline compounds which are retained in the sleeve filter.

The remaining heavy metal compounds are removed from the gas and are retained in the
double fines filter. The dust collected in Stages III and IV is packed into drums and deposi-
ted at a waste disposal site.

Of the outlet-gas stream 2000 Nm3/h was tested during pilot plant operation. Measurements
were taken before, after and in between the various stages so that the treatment efficiency of
the seperate stages and the treatment process as a whole could be ascertained.

All the outlet-gas values were well below those stipulated by the law at that time (TA-Luft
83) so that the values are still below those stipulated by the existing law (TA-Luft 86). In to-
tal 50,000 m3 of Neckar sediments with an assumed cadmium content of 500 kg produce a
dust emission of 1 - 3 kg and a yearly emission of less than 2 g cadmium into the atmos-
phere.
            fresh water
            clay
              gas
             Ca(OHb
                                       Neckar - Sludge
                                        50.000 m'/a
> sorting
dewalering
                                        mixing
                                        combustion
                                        grading
                                                            coarse fraction 1.3 t/h
                                                                 water  4,6 m'/h .Neckar
                 	     building
                  expanded         \ material
                  clay       *t/n    / SOJDOOmVa
                                                         outlet-gasl2.000 NmYh .atmosphere
                                                               filter-dust 12 kg/h .land-fill
 Fig. 5.     [Expanded Clay Production using Neckar-Sludge -  Throughput
                                         IZOBLJNI
                                        239

-------
                                                                     interim store
                                                                     Neckar-Sludge
Fig. 6.      (Expanded Clay Production using Neckdr-Sludge -' Site plan
IZDBLINI
                                         240

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                      FORUM
                        on
INNOVATIVE HAZARDOUS WASTE TREATMENT TECHNOLOGIES:

            DOMESTIC AND INTERNATIONAL
                   Atlanta, Georgia
                June 19, 20, and 21, 1989
      OXYGEN ENHANCEMENT of HAZARDOUS WASTE
                INCINERATION WITH THE
       PYRETRON THERMAL DESTRUCTION SYSTEM
             by Mark Zwecker, Fred Kuntz,
                  and Gregory Gitman
             of AMERICAN COMBUSTION,  INC.
                  NORCROSS, GEORGIA
                         241

-------
 ABSTRACT

      A  SITE program demonstration  of  the  PYRETRON® Thermal
 Destruction System was conducted at  the  EPA's  Combustion Research
 Facility (CRF).   The PYRETRON TDS, developed  by American Combus-
 tion, Inc.  (ACI)  of Norcross,  Ga. ,  was  installed  on the pilot
 scale rotary kiln  incinerator.   The  demonstration tests  were con-
 ducted using waste material from the Stringfellow Superfund site
 near Riverside,  Ca.  with a  high heating value decanter tank tar
 sludge waste from  coking operations.  The  test objectives were to
 evaluate ACI's claims that the PYRETRON  TDS  is capable of achiev-
 ing:
           Control  of  transient discharges  of POHCs and PlCs
           during operating upset  conditions;
           Higher waste feed  rates  than conventional incineration;
           Economic system operation.

      The demonstration test  results showed that ACI's  PYRETRON
 TDS achieved the RCRA 99.99  percent  POHC DRE at a waste feedrate
 which was 100% .greater than  the  maximum rate achieved under con-
 ventional incineration.  Measured particulate  emissions  from the
 PYRETRON testing were significantly less than  the required 180 mg
 per dscm corrected  to 7 percent oxygen.

      The PYRETRON TDS was also tested at the maximum conventional
 system  feedrate  but  with  a  60% increased  mass  charge  size.
 During these tests the PYRETRON system was capable  of  handling
 the increased charge  mass without unacceptable levels of "puffs"
 generation.   The concentration  of POHCs in the ash  residue  was
 consistently below detection limits.

 SITE Demonstration Test Program

      American Combustion,  Inc.  was selected as one of the  first
 participants  in the EPA's Superfund Innovative  Technology Evalua-
 tion (SITE) program.  The SITE program aids in  the commercializa-
 tion of  alternative and  innovative  hazwaste  treatment   tech-
 nologies .

      Within  the  SITE program, ACI performed a demonstration of
 the  PYRETRON  Thermal  Destruction  System  (PTDS).   The PTDS  is an
 oxygen enhanced combustion  system using ACI's patented technology
 designed for waste incinerators.  The  PTDS also incorporates a
 proprietary  process  control  algorithm  designed  to anticipate,
 detect, and respond to prefailure conditions within  the system.

     The  testing and evaluation  of  the PTDS  took  place at the
 EPA's  Combustion Research  Facility  (CRF).   The  CRF  is  a  fully
permitted incinerator established by  the  EPA to conduct incinera-
 tion  testing and research.   The  testing occurred at the end of
 1987 and beginning  of 1988.

     ACI, the EPA,  and Accurex,  the operating  contractor of CRF,
developed a test program to  evaluate  the  PTDS versus a conven-
tional air based incineration system.   The  test program objec-
tives were:                                                  J
                              242

-------
1.


2.



3.
         Evaluate  the  PTDS'  ability  to  reduce  the  magnitude
         and/or number of transient upsets ("puffs");

         Achieve  the RCRA  99.99% ORE  at significantly  higher
         feedrates than that attainable in the conventional sys-
         tem ;

         Improve  the overall system economics compared  to the
         conventional system.

     For these  tests the  only change  to the system  involved
removing the existing conventional burners and installing ACI's
PYRETRON TDS.  A schematic of the PYRETRON system used in the CRF
tests is shown in Figure 1.

     The tests  involved  the  incineration  of waste  from  the
Stringfellow Superfund  site  spiked with decanter tank tar sludge
(listed K087 waste) at a 2/3 ratio respectively.  K087 waste con-
tains  high  concentrations  of  several  hazardous  polynuclear
aromatic components.  The  K087  waste was  added to increase the
level of volatile contaminants in the feed matrix.   The resulting
volatility  of the  waste,  therefore,  provided a much  more dif-
ficult test for  the capabilities of the  PTDS.   Table  1 of the Ap-
pendix  contains the  chemical  analysis of  the  waste  mix used in
the CRF testing.

     The test program included scoping tests of the  conventional
system  as well as  the PTDS.   These scoping tests  were performed
to maximize the  total mass  feedrate of the  waste mix  in both sys-
tems.  The  maximum  feedrate  for  each  system was determined by the
system's ability to  incinerate  a charge  mass  without exceeding
regulatory  CO  limits in  the afterburner exhaust.   Additional
testing was done with the  PTDS at  the conventional  system's maxi-
mum  feedrate but with  a 60% larger charge mass.   This test was
used  to provide data  to  confirm the  PTDS'  ability to control
transient upsets.
                           243

-------
  FIGURE 1 - SCHEMATIC  OF  THE PYRETRON THERMAL
             DESTRUCTION SYSTEM TESTED AT CRF
                                                Measured
                                                 process
                                               parameters
                                                 Valve train
                                               (gas, oxygen, air) •
                                               J
                                       Gas, air, and oxygen
                                       flows to the burners
Ash pit
PYRETRON THERMAL DESTRUCTION SYSTEM
            PROCESS  DIAGRAM
                       244

-------
Test Results

     The optimum mass  feedrate of the conventional system was es-
tablished at  105 pounds per hour.   This rate was accomplished by
feeding mass  charges  of 21 pounds  every 12 minutes.   Data ob-
tained from the conventional system  during this test is contained
in Figure 2.

     Figure 3 shows data from the conventional system operating
at a charge mass  and  interval slightly above  the  optimum.  The
operating data  at  this feedrate shows many  failures  due to the
depletion  of  available  oxygen  in  the  kiln atmosphere.    As a
result, the system experienced flame failures,  system pressure
excursions,   and  excessive process temperatures  commonly as-
sociated with the development  of "puffs."  The conventional sys-
tem was  incapable at  the  increased feedrate  of simultaneously
maintaining sufficient excess  oxygen and reducing' auxiliary fuel
input to control the upset.

     The corresponding optimum mass  feedrate  for  the PTDS was es-
tablished at  210 pounds per hour.    This rate was accomplished by
feeding mass  charges of 21 pounds  every 6 minutes.   Data for the
PTDS  during   this  test  is  shown  in Figure  4.    The  feedrate
demonstrated  by the PTDS is twice  the optimum  feedrate of the
conventional  system.

     Stack test results showed that the PTDS was able to achieve
greater than  99.99% ORE at the  increased  feedrate.  Stack samples
taken  during  the optimum feedrate  test  run did not  detect any
POHC.  There  was also  no detection of POHC within the ash residue
or scrubber effluent from this  test. The PTDS  also operated well
within the regulatory  limit  of  180 mg per dry scm for particulate
emissions.  Table 2 located in the  Appendix  lists the results of
the stack particulate  testing.

     Figure 5 shows the data for the PYRETRON system at a  charge
mass of  34 pounds and a charge interval of  19 .5 minutes.   'This
charge mass represents a 60% increase over the  optimum mass which
the conventional system could  handle.   Under  these operating con-
ditions, the  PTDS provided enough oxygen  to the system to control
CO discharge from the kiln.   As a result, the  afterburner  system
was  not  overloaded  at  these  conditions  and failures  were
prevented.
                               245

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                                 FIGURE 2
                   C.R.F. Kiln .Data for 12-09-87

                Conventional System—21  lbs/12  min
   2200
in
800C




6000




<000




200C
       V

v^s^yv^iv'-V^^^vV^JX^J/V^A^
    30
 -.  15
 C
   500
   250



    0
                                    Propone
                -.•0
                         100
                                   ISO


                                 Minutes
                                         200
                                                             300
                                       nr
                                        y
                                      i •/
             Storting Time : 12:40
               50
                        100
                                  150


                                'vlinules
                                        200
                                                  250
                                                            300
                                 246

-------
                          FIGURE  2 (CONTINUED)

              C.R.F. Afterburner Doto for 12--O9-37

              Conventional  System—21  lbs/12 min.
o

t)
  2200
  200O
  ieoo  -


       f
         Slorlinc Time : 12:40

                '     	^	.	L.
  1.6EX







I

 3OOO.O




 4000.0





   0.0
                                                          Propone x 10
                50
                         100
                                   150

                                 Minutes
                                             200
                                                       250
                                                                 300
f-l
z
CJ
o
c:
(J
      ~  STARTING TIME-12:40
   10  —
                50
                        100     ISO      200

                               MINUTES
250
                                                           300
                 C.R.F. Stack Data  for 12-09-87
              Conventional System —21  lbs/12 min.
    55 r
O.  'jl
O.

0   v
o   °-
         Steeling Time : 12:40
                                               Measured at Slock Exit
    '-5 f
               50
                         too
                                   150

                                  Minules
                                            200
                                                      250
                                                                ioo
                             247

-------
                                   FIGURE  3
                    C.R.r.   Kiln Data  for 12-08-87
                Conventional System — 24 ibs/10  min.
   2200 ,	
       V

       f.   Storting Time : 10:27
 u.     r.                -
o      J. •

 .. 2000 f-
 ^     S
   eooo

JC

y  6000



g  <000

iZ

   2000



     0
                      100
                                 Aif

                                 Propone
                                    200

                                   Minutes
                                                   300
                                                                  400
                                                 SlorUng Time : 10:27
                     100
                                    200

                                   Minules
                                                  300
                                                                 
-------
                         FIGURE 3 (CONTINUED)

               C.R.F.  Afterburner Doto for 12 — 08-87
                Conventional System--24 !bs/10 min.
  . 2COO -
 o

 p" i500
c
73
  aooo.o


  4OCO.O


    o.o

          Storting Time : 10:27
                                  200
                                               300
                                                             400
                                                           400
                   C.R.F. Stock Dato for 12-08-87
                 Conventional System —24 lbs/1 0 min.
95
70
E
O.
a.
45
O
-
-


-

r
20 L
0
;
Storting Tim*
Measured ol
Sleek Exit





.







1







10:27









0 1 00 200
















,1



i


















1 , ._.» 	








_








	








_








_

















, 	








t








._ _.
300 ^00
Minules
                             249

-------
                     FIGURE 4
             C.R.F. Kiln Dota For I -2 I -8b

          Pyretron System —21 lbs/6 minutes
  2200
  2000
  taoo
  300O
  6003
10

S 4000
o
  2000





    0
       Slorling Time : 12:00
^v^
            50
                   100
                         i/V
                     150


                   Minules
f^/
                                200
                                          v- Oxygen
                                      Propone
                                        250
                                              JCO
   20
   >0
  SCO
c eco
o.
CL

R 
-------
                           JIGURE .4  (CONTINUED)


              C.R.F.  Afterburner  Data for 1 -21 -88

                   Pyretron System—21 lbs/6'min.
   ^200
jo  MOO


D

O



Q.  180O
   t.8H:'i -
         Storting Time : 12:00
                                    150
                                              200
                                                         250
                                                                   3OO
 C-I

 z
 o
 w
 cu
    25
    20
    15
    10
          STARTING  TIME - 12:00
                                                     .END OF
     0 III .  i  .1 I  I  I .  I  I  II I	1	1	1	1	1	1	1	1	1	!	!	1	1	1	!	!	!	1	L.


         0        50      100      150      200      250      300
    95
    75
 a.


8  35
    15



     0
          Stociing Time : 12:00
                50
                          1OO
                                    150


                                  Minules
                                              200
                                                        250
                                                                  3OO
                            251

-------
                                    FIGURE  5
                      C.R.F.  Kiln .Date  for  I,-14-88
                 Pyretron  Sys.tern— 34 !bs/19.5 minutes
    2200
                                       150

                                     Minuies
                                                                        300
     20
  _.  15
  C
  
-------
                     FIGURE 5  (CONTINUED)
 2200
            C.R.F. Afterburner Data for 1-14-88
           Pyretron System-34  lbs/19.5 minutes
2000
  0.0
                                                 250
                                                          300
       STARTING TIME - 13:10


              I  I  I T I  I 1	1	1
                     100
ISO      200

MINUTES
                                            250
                                                    300
                            253

-------
FTPS Process Improvement Summary

     The process improvements provided by'the PTDS result  from  a
more  efficient  burner  design  and  a process  control   system
programmed to  adjust  the  process parameters required to  improve
destruction efficiencies for hazardous constituents.   The  burner
design incorporates a second more concentrated  oxygen stream into
the  flame pattern.    Figure  6  shows an  illustration  of  the
PYRETRON burner flame pattern.

     Oxygen is fed at sub-stoichiometric  rates  into the  center of
the flame.   Even  at  sub-stoichiometric  rates  the  heat release
within this  core is  sufficient  to cause pyrolysis  of  the  sur-
rounding fuel.  The pyrolysis products of  combustion  in  this zone
are more highly radiative at the  temperatures developed.   Conse-
quently,  energy is rapidly transferred from  this  zone to the sur-
rounding atmosphere.   Flame temperatures  are, therefore, reduced
from those typically  achieved  by traditionally designed burners
at the same oxygen enrichment level.

     Air is fed around the periphery of the  fuel  zone to create  a
cooler combustion  zone at the edges of  the flame pattern.  At
this point  the fuel  is burning  from  inside and  outside  of  the
flame pattern.  By directing the  various process  streams from the
burner, a third zone  is created  in which  the combustion products
from the pyrolytic and  excess  oxygen zones  are combined to  com-
plete the combustion  of the fuel.   This results  in a  high combus-
tion efficiency even  at very low  stoichiometric  ratios.  In addi-
tion,  highly  reactive excess oxygen  exits  the  stable  flame  en-
velope at elevated temperatures.

FTPS Control

     The PTDS  is preprogrammed  to respond to  changing process
conditions to maintain high destruction capability.   The response
capability of the system involves an  instantaneous change  in  the
level  of  participation  of the  two  oxidizing  streams.   ACI' s
proprietary control algorithm provides a  series  of   responses to
various instrument readings to maintain  optimum process  condi-
tions.   Conditions such  as system pressure, insufficient  excess
oxygen levels, high  CO concentrations, low afterburner tempera-
ture,  as  well as  other potential  "upsets"  can be contained  by the
changes initiated by  the PTDS.

     The  PTDS designed for the CRF testing was preprogrammed  for
three  response actions.   One response  action  involved   adding
oxygen in anticipation of a batch charge.   At a preset  interval,
a signal  from the ram feed mechanism alerts  the PLC  that  the
waste charge would soon be introduced into the furnace.   The  PLC
then automatically responded by changing the oxygen participation
rate to change the furnace atmosphere to include a  significant
amount of hot, highly reactive  oxygen  before the mass charge.

     The response  action  to a batch charge signal  is  shown in
Figure 7.
                              254

-------
                       FIGURE 6
                AIR
    AUXILIARY FUEL
OXYGEN
                 z
                           AUXILIARY FUEL COMBUSTION ZONE
HAZARDOUS WASTE
INCINERATION ZONE
                                       FINAL COMBUSTION ZONE
        PYRETRON  INCINERATION PROCESS
                          255

-------
               FIGURE 7
D
cr
cr>
      Batch

     Charge
      Signal
On
On
                            Air
c.
D
Z5
o
      Oxygen
                 Time

            PYRETRON

          Oxygen Based

         Control Response

                to a

       Batch Charge Signal
               256

-------
     As a result of the PTDS'  response,  the  potential  for deplet-
ing oxygen at the  initiation  of  the charge into the  furnace was
reduced.   Therefore,  the  reaction  of  the volatiles in the batch
charge was completed  thus preventing the  generation of much of
the "puffs" that occurred in the conventional  system.   A water
quench spray,  controlled by the PLC, was used  to dissipate excess
heat released from  the charge.

     Another  response  action programmed   into the  PTDS  is  a
response to system pressure  excursions.   This  response,  repre-
sented in Figure 8, permits  the  quantity of oxygen fed into the
system to be  maintained while  the total  gas  volume  is  reduced.

By changing the oxygen  participation  rate,  the volume of inerts
fed into  the system  is reduced.   As  a  result,  the total gas
volume does not  exceed the maximum  that  the  system  can handle and
fugitive  emissions from  the  kiln  seals are  prevented.    This
response is also useful for systems  which must maintain a minimum
gas residence time.   The response  sequence can also be used to
modulate low afterburner process  temperatures.

     The third response action, represented in Figure  9, involves
a  response  to  kiln exhaust  gas analyzer  signals that  show a
depletion  of  oxygen  or an increase  in CO exiting  the primary
chamber.   When the  analyzer showed  that  adjustments in the excess
oxygen amount were  required,  the  PTDS  would again adjust the par-
ticipation rate to prevent a  failure  mode  from occurring.   This
response action  is  also useful for  responding  to a  furnace oxygen
deficiency or an excessive combustibles  feed rate to  the system.
                               257

-------
                         FIGURE 8
3
W
CO

£
Du
System Pressure

AWFSO Point
             Pressure
                Air
3
a
              Time
                       Oxygen
      PTDS

  Oxygen Based

Control Response

       to

System Pressure
                                Also:
                             Low Gas Residence Time


                             Low Afterburner Process

                                   Temperature
                            258

-------
          FIGURE 9
cd
O
o
O
v


>^
u^
c
co
O


(Possible
CO Level
CO Level *' \ on Air onIY
AWFSO Point £ \ Control)
» *
Control: v/^^N^ \
CO Level _/ ^ ^xi----..



'Air
Oxygen

                          PTDS
                      Oxygen Based
                    Control Response
                           to
                    Carbon Monoxide
                Also:
                    Deficient Oxygen

                 Excessive Combustibles
                       Feed Rate
Time
            259

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Conclusions

     The EPA's Site program tests showed that the  PTDS  is  capable
of improving the environmental and economic performance of a  con-
ventional incineration system.   The PYRETRON system  accomplishes
these improvements by  a  combination  of innovative burner  design
and  dynamic  process  control.     Specifically,   the  EPA tests
demonstrated that ACI's PYRETRON technology will:

     1.   Provide increased waste throughput capability by  con-
          trolling "puffs" and improving DRE;

     2.   Only  require  a   modification  to   the  existing
          incinerator's combustion and  combustion control  equip-
          ment to achieve the  PYRETRON technology  improvements;

     3.   Achieve destruction efficiencies  well  above required
          levels;

     4.   Eliminate transient releases of POHCs  and PICs to the
          environment by the system's  preprogrammed Transient Up-
          set Control response action;

     5.   Handle  as  much as  a  60%   increased   batch load of
          volatile wastes without increasing hazardous  emissions;

     The PTDS is applicable to  any waste treatment incinerator,
including medical waste,  which requires efficient  control  for en-
vironmental compliance.  The PTDS  is being  marketed  commercially
by American Combustion, Inc.

     American Combustion,  Inc.  has  over ninety  commercial  ap-
plications which use  the  PYRETRON technology.  These  applications
include electric  arc furnaces,  copper smelting  furnaces, glass
tanks, ladle  heaters,  and lead  and aluminum refining  furnaces.
All of these  applications  use ACI's  PYRETRON combustion systems
as well  as various  aspects  of  ACI's  patented dynamic control
technology.
                               260

-------
APPENDIX
      TABLE 1 -     CHEMICAL ANALYSIS OF WASTE  FEED MIX
                 USED IN PYRETRON TDS DEMONSTRATION TESTS
    Component

Naphthalene   (C10H8)

Phenanthrene   (CgH4CH)2

Acenaphthalene   (Ci2Hg)

Fluoranthene   (C16H10^

Pyrene   (C16H10)

Anthracene   (C6H4CH)2

Fluorene   (C6H4 CH2 C6H4)

Dibenzofurane   (CgH4)20

2-Methylnaphthalene   (C10H? CH3)

Miscellaneous PolyNuclear Aromatics

Miscellaneous Unknowns
Concentration, ppm

      49,772

      22,569

      11,722

      11,529

      11,036

       6,764

       6,397

       3,926

       3,457

       5,017

       1,031
                               261

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      TABLE 2 -
PARTICULATE EMISSIONS DATA
                         Particulate
                        Concentration a/D
                          Particulate
                         Concentration c
Test
1
2
3
4
5
6
7
8
System
Conventional
Convent iona 1
Conventional
Conventional
PYRETRON TDS
PYRETRON TDS
PYRETRON TDS
PYRETRON TDS
ma/dscm
" 8
9
47
29
28
10
28
39
ma/dscm
4
4
28
19
24
7
17
20
aCorrected to 7% oxygen for the air-only tests.

kpYRETRON tests were corrected to 7% oxygen considering the
 effect of oxygen enrichment.

GUncorrected
                                262

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            T©st     ResunlLts     with
     smm       C emit riff MS a I
        R.C. Eschenbach, R.A. Hill & J.W. Sears
                          HN€   UKIAH, CA
Forum on Innovative Hazardous  Waste Treatment Technologies:
               Domestic and  International
                   June 19-22  1989
                     Atlanta, GA
                         263

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TITLE:
AUTHORS:
 INTRODUCTION:
PROCESS DESCRIPTION AND  INITIAL TEST  RESULTS
WITH THE PLASMA CENTRIFUGAL REACTOR

R. C. Eschenbach, R. A. Hill, and J. W. Sears. Retech.Inc. Ukiah,
California
During the last few years Retech, Inc. has developed the Plasma Centrifugal Reactor (PCR)
to stabilize solid waste material while decomposing any toxic hydrocarbons into relatively
innocuous, simple molecules. The PCR uses heat from an arc to melt and vitrify solid
components, thereby accomplishing the decomposition and stabilization of the waste.
Plasmas can produce temperatures  in excess of 10,000°C although the expected
temperature to be produced in the molten glass will be about 1600°C.

The development of this furnace has been achieved through a three phase program.  The
first phase was directed at reducing the volume of radioactive mixed wastes. Initial tests
were  performed at Ukiah in Retech's 100 kW lab-scale plasma furnace, followed by
demonstrations on surrogate materials in a titanium production furnace located at Oregon
Metallurgical Corporation, Albany, Oregon.  In phase two of this program a quarter-scale
PCR was designed, built and tested at our Ukiah facility. During this phase the first patent
covering the plasma centrifugal furnace was issued (U.S. Patent # 4,770,109). The final
phase of this program will be to evaluate the performance of a full size  furnace.
Preliminary tests were performed in Ukiah (March-May 1989), while further tests will be
run by the U.S. Department of Energy (D.O.E.) at their Magnetohydrodynamics facility in
Butte, Montana, as part of the EPA's Superfund Innovative Technology Evaluation (SITE)
program (summer 1989).

PHASE I  (1985-1986)

The initial tests, conducted with  a transferred-arc plasma on materials (metals, glass,
rubber, plastics, filter elements, etc.)  like those which get radioactively contaminated,
demonstrated the effectiveness of volume reduction. The first tests were made in our lab-
scale furnace by melting down pint cans filled with plastic gloves, rubber, ceramics and
chunks of metal.  Scale-up tests with an argon arc at about 1500 amperes and 130 volts
were conducted on 4 liter steel cans stuffed with simulated waste. The resulting volume
reduction was found to be a factor of 20 with the corresponding weight reduction at a factor
of 1.8.X1) Problems with arc stability were encountered; contributing factors were vision
                                     264.

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problems caused by sooting shortly after each can was added and limited power supply
voltage. It was concluded that the addition of oxygen or air as an oxidant in the plasma gas
would be desirable in order to convert hydrocarbons to carbon dioxide and water instead of
soot, carbon monoxide and hydrogen.
                                                  water-cooled
                                                  copper electrode
             plasma gas
             injection  -v
                                                        arc  termination
                nozzle
                                                             slag bath
FIGURE 1:  Schematic of the quarter-scale reactor showing the orientation
	of the plasma torch with respect to the rotating tub.	
PHASE II (1986-1988):

The first plasma centrifugal reactor was developed with a 150 kW transferred-arc plasma
torch operating on air or oxygen-argon mixtures.  The furnace design incorporates a
stationary plasma torch with a revolving tub (45.7 cm ID-18 inches) inside a sealed reaction
chamber. The centrifugal force imposed upon the molten material moves it to the outside of
the chamber, where mixing of new feed material is accomplished.  Figure 1 shows the
orientation of the plasma torch with respect to the revolving tub.

Operating with an oxidizing environment greatly reduces the sooting associated with
straight pyrolysis. Tests were run with a number of feedstocks after completing assembly
and debug in July, 19872.  Liquid feeds such as water, methanol, and fuel oil were fed at
uniform rates.  A spoon feeder permitted adding dirt or dirt and hydrocarbon mixtures
                                       265

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(polymers and such)  in 0.5 to 1.0 kg quantities every 5 to 15 minutes. An effluent gas
treatment system which includes a quench spray followed by a rock tower was used to
cool, neutralize and separate particles from the acidic exit gas. An air-ejector located in the
exhaust duct was used to maintain the furnace pressure below atmospheric. Tests showed
that the non-volatile components  retained in the vitrified mass are non-leachable as
determined by standard tests.  This furnace was originally designed to 'tilt-pour1 but it was
found that the molten glass became too viscous to allow pouring of the material from the
furnace.
                                                WATER-COOLED COPPER ELECTRODE
                                                     PLASMA GAS INJECTION
     ARC
 TERMINATION
   SPINNING
   REACTOR
     WELL
                        EXIT GAS AND
                       SLAG REMOVAL
 6
« o
                                               *o
FIGURE 2:  Schematic  of the demonstration reactor  showing the bottom
              pour configuration for exit gas and  molten glass.	
Work with the quarter-scale reactor resulted in the EPA selecting the PCR for inclusion in
the second round of the SITE program.  We decide to design a larger reactor for the
demonstration program (Phase IE), using the insights gained from the quarter-scale reactor
tests.
                                      266

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WASTE
4
FEEDER

VACUUM
^ PUMP
^ -i
CENTRIFUGAL
REACTOR
^ PLASMA ^ POWER
' TORCH SUPPLY
^ 4
SECONDARY
CHAMBER
|
QUENCH
TANK
t
JET
SCRUBBER
t
PACKED
TOWER

OXDEING
* — GAS

k
SURGE
TANK
' t
BUTTERFLY
VALVE



f
GAS
ANALYSIS
L


VEN
ATMOS
i
TTO
PHERE
i
STACK
FAN
4k
CHARCOAL
ADSORBER
t
BUTTERFLY
VALVE
t

t

FIGURE 3:     Block  diagram of the  PCR-6
PHASE HI  ( 1988-PRESENT)

Design of a large PCR was started in late 1987. This reactor was dubbed the PCR-6 since
it had a 6 foot diameter reactor tub. The design incorporated a bottom port for both exit gas
and molten glass Melt chamber geometry is shown in figure 2. Figure 3 displays a block
diagram of the major components of the PCR-6. The reactor section consists of a feeder,
primary chamber, rotary throat, drive mechanism, secondary combustion chamber and the
glass collection chamber. The gas treatment system consists of a quench tank, jet scrubber,
packed bed scrubber, demister, activated charcoal adsorber and a stack blower. Figure 4
shows a schematic diagram of the system elements.
Hazardous waste is initially loaded into a feeder. Depending on waste type, it may be a
screw, Archimedes spiral or a conveyor. In the Preliminary Tests for the EPA, specially
prepared, spiked soil known as Synthetic Soil Matrix (SSM) was charged from 5 gallon
                                       267

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containers into a screw feeder or an Archimedes spiral feeder.  The latter feeder will be
used to accept the contents of 55 gallon drums containing contaminated soil from actual
superfund sites in Butte. The next generation reactor will be even larger (2.4 to 3 m in
diameter); this will accommodate feeding of whole drums.
                                        ROTATING REACTOR WELL
FIGURE 4:    Schematic  of PCR-6  showing  the  feeder, primary and
	secondary chambers and the gas  treatment system.	
During feeder loading operation, a plunger valve isolates the feeder from the hot reactor.,
Air is purged through the feeder into the reactor to insure that no toxic vapors are present
upon opening the feeder door. Once loading has been accomplished, the feeder is sealed
from atmosphere and the plunger valve is opened to access the waste material into the
reactor.

The reactor itself consists of three chambers: a primary reaction chamber in which the
plasma torch is located, a secondary chamber where incomplete combustion products react
with supplementary oxygen to form water and carbon dioxide and a chamber where the
molten glass is collected. Inside the upper chamber is a rotating tub about 1.8 m (6 ft.) ID,
which spins at about 40 rpm. The plasma torch provides one termination of a DC arc, with
the other termination being initially the copper throat of the rotating tub. The walls of the
tub are lined with refractory material and a "skull" consisting of solidified waste material
(vitrified soil) built up during previous runs. The skull begins to melt under the action of
                                      268

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the torch and eventually becomes a conducting medium. When the waste material becomes
sufficiently molten to be able to conduct, the plasma torch can be adjusted to move away
from the copper throat and onto the molten glass. This process continues most of the
surface of the rotating tub has been treated and turned to glass. When all of the waste
material in the rotating tub has been treated, the feeder is started and new waste material is
fed into the reactor. During feeding, the reactor is rotated at sufficiently high speeds to
keep the new feed material from rolling down to the throat of the rotating tub.

The waste material that is fed into the reactor falls into the existing melt and is itself melted
by interaction with the plasma. Any organic contaminants that the waste contains will be
vaporized and burned in  the oxidizing atmosphere of the upper and lower chambers. The
inner core of the plasma column can reach temperatures of over 10,OOQ°C which maintains
the ambient temperature in the upper chamber above 1000°C. At such temperature, organic
vapors that have been released from the waste will immediately burn when mixed with the
hot oxygen rich furnace atmosphere.

Feeding continues until material build up causes the glass to reach the point of flowing into
the copper throat The feeder is turned off and time is  allowed to complete the removal of
any organic material. This is determined by the change in oxygen level in the exhaust and
the clearing of soot as observed in the upper chamber. Upon completion of vaporization
and melting of the waste, the speed of the revolving reactor tub is slowed. Rotating the tub
at speeds of 5 to 10 rpm will allow gravity to overcome the centrifugal force on the molten
glass and allow it to flow through the center hole, falling through the secondary chamber to
be collected in the chamber below. The molten glass is collected in a pig mold where it
later solidifies. After the molten glass has been tapped the rotational speed of the reactor is
increased to resume the process. Presently the glass is allowed to cool in the collection
chamber. In the future, an air lock will facilitate the replacement of the full glass mold with
a new one to allow uninterrupted operation.  The  process, treating wastes,  reacting
organics, casting glass and then resuming treatment continues until a planned shutdown.
Shutdown consists of turning off the plasma torch, allowing time for the molten material in
the reactor tub  to solidify to form the refractory layer for the  next operation, and then
stopping the tub rotation.

During the melting process,  gases move out of the primary chamber through the throat into
the secondary chamber.  If combustion of the  organic material is not complete in the
primary chamber, additional O2 is injected into the secondary chamber in the vicinity of the
throat to cause further combustion, which is completed before the gas flows around a baffle
and out into the gas treatment system. Gas temperature in the secondary chamber reaches
                                      •269

-------
 at least 500°C. Since the exit duct is refractory lined, exhaust gas arrives at the quench
 tank at nearly the same temperature. Since air is used as the source gas for the torch, the
 gas stream will be acidic due to the formation of NOX from the reaction of N2 with C>2 at the
 high temperatures of the plasma.   HC1 formed  from the break down of chlorinated
 hydrocarbons will also add to the gas acidity. Other gases in the exhaust will include the
 combustion products COa and water vapor, plus excess 02- In the event that combustion
 is incomplete, CO will be formed. If CO levels are considered to be excessive, the system
 will be placed into a recirculation mode as discussed below.

 There are several cooling circuits associated with the furnace. The torch circuits are cooled
 by  a high velocity distilled water system. This system is closed loop, consisting of a water
 pump, heat exchanger, flow interlocks for each circuit and a pump discharge filter. All
 parts of the rotating reactor well exposed to high temperatures are cooled by a glycol-water
 system similar to the distilled water system described above. The remaining cooling
 requirements for the furnace  are met by circulating water from an open loop building
 system. These circuits include the reactor lid, reactor chamber upper (non-rotating) wall,
 secondary chamber walls, collection chamber and hydraulic system.

 GAS TREATMENT SYSTEM

 The gas  treatment system consists of four parts: scrubber, sampler, recirculation and
 exhaust.  The scrubber is composed of four separators, two pumps and a  tank.  The
 sampling system includes a pump and monitors for CO2 and O2. Recirculation consists of
 a surge tank and a water ring vacuum pump. .Exhaust system is comprised of ducting, a
 charcoal bed and an exhaust blower.

 The gas stream exits  the reactor via the secondary chamber exhaust duct.  The gas then
 enters the scrubber where it first passes into a quench tank encountering a fine spray of a
 mild caustic solution (NaOH).  This  solution is intended  to react  with  the acidic
 components of the gas and neutralize them. The caustic solution is circulated through
 scrubber elements by means of two high pressure pumps. The  quenched gas is then
 directed into the jet scrubber, which is designed to reduce the pahiculate load in the gas.
From the jet scrubber the gas enters the bottom of a packed bed tower.  The packed bed
consists of one inch pall rings with a spray at the top of the column.  The gas is then drawn
into the demister which is a dry packed bed.

After leaving  the demister the gas enters a serpentine duct constructed for sampling
equipment.  The distances between  and location of the ports were determined by the
                                      270

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requirements of the various analytical samples to be taken.  One sample train is used for
control. A diaphragm pump delivers the gas sample to O2 and CO monitors. The O2 and
CO levels help determine the effectiveness of combustion.  Excessive CO levels will
require activation of the emergency  bypass valve allowing the system  to go into
recirculation to prevent the release of toxic vapors. The initial set point for CO level will be
determined during further testing.
FIGURE 5:     Photograph of the PCR-6 installed in the Ukiah lab.
The recirculation system includes two air operated ball valves which respond to a signal
from the control panel. Under normal conditions the valve to the exhaust stack is open and
the valve to the surge tank is closed. During operation the surge tank is kept evacuated by
the water ring vacuum pump. Upon initiation of recirculation, the valve to the stack closes
and the valve to the surge tank opens. There is enough volume in the surge tank to operate
for about 5 minutes, time enough to correct a problem.  If the abnormal CO levels persist
after 5 minutes the system would be shut down.

Following the recirculation system the gas enters the exhaust stack blower which is capable
of producing 80 in. of HaO at 100 cfm. At the outlet of the blower is a charcoal bed
adsorber to remove any residual organics not detected by the sampling system.  It was
                                      271

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 found during the preliminary tests that the charcoal adsorber became loaded with
 condensate, rendering it useless as a gas adsorber. Therefore it has been removed from the
 system. A stack blower raises the gas pressure to atmosphere for release.
FIGURE 6:     Photograph of PCR-6 showing the  feeder, plasma torch and
	primary melt chamber during feeder reloading operation.
TEST RESULTS

A photograph of PCR-6 installed in the Ukiah lab is shown in figure 5. This picture shows
the layout of the facility.  The closed cooling water systems can be seen in the lower right
hand corner.  The plasma torch can be seen protruding from the top of the reactor. The
primary melt chamber and drive chamber are the main features of this photograph. Figure
6 gives a good view of the plasma torch and feeder. The operators are in the process of
placing material into the feeder. During the operations with the spiked SSM the feeder deck
was an exclusion area while the surrounding space in the reactor room was a control area.
The off-gas treatment system is shown in figure 7; the large tank to the left is the surge tank
while the components in the center of the picture comprise the gas treatment system.

Shakedown tests with the PCR-6 were completed using local soil and oil (15% by weight).
These tests were done before and after the preliminary tests for the SITE program. During
                                     272

-------
these tests we were able to feed up to 200 Ibs/hr of oil and soil.  Initial runs were
performed using argon as a torch gas. The argon arc proved to be unstable in the current
configuration because of the interaction of the plasma with the chamber atmosphere. It was
found that high moisture contents caused this instability. Further testing showed that air
was a much more stable plasma gas when interacting with the furnace atmosphere.  The
plasma torch will operate satisfactorily with air as a plasma gas at arc currents up to 1200
amperes at 400 to 600 volts. In cases where the moisture content was low the plasma torch
was able to operate with argon gas at up to 1200 amperes and 400 volts. Use of Qz/argon
mixtures as plasma gas proved unsatisfactory due to shortened electrode life.
 FIGURE 7:  Photograph of PCR-6  exhaust gas treatment system.
 Preliminary tests for the EPA SITE program were run using Synthetic Soil Matrix (SSM)
 (both unspiked and spiked material) (See Table 1) which was prepared by Enviresponse,
 Inc. Preliminary Test #1 was performed on 20 April, 1989 using argon as a torch gas on
 550 Ibs of unspiked SSM. The second preliminary test was conducted on 25 April on 300
 Ibs of spiked SSM using air as a torch gas. The third preliminary test was conducted on
 April 26.  An air plasma was used to treat 200 Ibs of spiked SSM.  Continuous Emission
 Monitoring (GEM) was performed during both shakedown and preliminary tests.  Data
 taken by the CEM included the levels of Oi, NOX, CO, and THC (Total Hydrocarbons).
                                       273

-------
 For the final preliminary test, samples were taken on the exhaust gas, which included
 VolatUes/Semivolatiles, Paniculate matter, Velocity/Volumetric Flow Rate (Method 1&2),
 Fixed Gases (Method 3), Moisture (Method 4), Flue Gas-Metals (Method 12), and HCL
 Samples were also taken from the slag, the feed material and scrubber water.
SYNTHETIC SOIL MATRIX (SSM)
COMPONENT
Sand
Gravel No. 9
Silt
Topsoil
Clay
WEIGHT %
31
6
28
20
15
SPIKING MATERIALS
COMONENT
Tetrachloroethylene
Anthracene
Bis (2-ethylhexyl) phthalate
Chromium
Zinc
mp/kg - ppm
3,277
7,361
3,702
1,898
28,306
Table 1     SYNTHETIC SOIL  MATRIX (SSM) composition  both spiked
  	and unspiked.	
Most important to the development of the PCR was the ability of the reactor to vitrify soil
and transfer that glass to a collection chamber. The bottom pour arrangement was proven
during the shakedown tests. As shown in figure 8, it was possible to produce a fairly large
area of molten glass. After an operating procedure was established it was possible to slow
the reactor speed and pour glass from the melt chamber into the collection chamber.  A
representative sample of the glass is shown in figure 9.  The slag produced during the
preliminary tests was similar to that shown.  At the time of this writing the results of the
leach tests were not yet available.

CEM results during shakedown tests on local soil indicated high levels of  NOX (up  to
15,000 ppm) on runs when air was used as a torch gas. This level of NOX amounts to less
than 1 Ib/hr at the system gas flow rate (~70 cfm). However, it was found that the level of
NOX dropped significantly (to 5000 ppm) when processing soils with organics  (oil) added.
This can be explained due to the competing reactions involved in the formation  of
                                      274

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combustion gases and NOX. During the shakedown tests the level of oxygen followed the
feeding patterns for soil with high organic loads as would be expected.  Shortly after
commencing feed, ah indication of lowering Qj levels was observed. This is an indication
of a reaction (combustion) between the decomposed hydrocarbons and O2- Additional O2
was injected into the melt chamber during subsequent runs to maintain an excess of O2-
During tests with excess C>2 maintained, a green colored flame was observed protruding
from the secondary combustion chamber into the collection chamber. This was a positive
indication of combustion in the secondary chamber.

Tables 2,3 and 4 give the GEM results for the three preliminary tests.  P-l was performed
with argon as a torch gas and unspiked SSM, therefore no additional Oa was needed. The
GEM results were consistent with this type of operation. The C)2, CQz, CO and THC were
low for the duration of the test as expected since no free O2 or hydrocarbons were
introduced. There were however some startup spikes as shown by the 1-min max results,
which at this time cannot be explained. Levels of NOX produced were attributed to purge
air from the feeder and collection chamber and small air leaks into the system.
PCR-6, P-l CEM RESULTS
MONITOR
O2 (%)
C02 (%)
NOx (ppm)
CO (ppm)
THC (ppm)
1-MIN MAX
6.3
18.1
4952
1003
115
1-MIN MIN
0.6
0.2
1045
0
4

1-MIN NORM
1.7
4.0
3500
4
6
Table 2     CEM  results from preliminary test #1, performed on  April 20,
             1989 using argon  as  a torch gas.        	
 Spiked SSM and air torch gas were used during P-2, in which 300 Ibs of material was
 treated. No additional O2 was added during this test in order to determine a base level of
 additions for P-3.  Levels of O2, CO2, CO and THC were all higher than in P-l as
 expected. Since air was used as a torch gas, the NOX levels were higher in this case but not
 to the levels observed when using air and unspiked soil.  The Oa level dropped  to 6.2 %
 during feeding operation. It was decided to try to maintain the level at ~ 13 % for P-3
 during feeding to try to insure complete combustion.  Unexplainable  CO spikes still
 occurred, even when not feeding.  One explanation for the CO spikes might be a periodic
                                      275

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  leak of ethylene-gylcol (cooling medium) from the copper throat area. The throat area had
  been a source of leakage during shakedown tests.

  Near the end of P-2, it was determined that there was enough slag buildup to facilitate a
  pour. The reactor speed was lowered and -100 Ibs of glass was tapped.  Samples of the
  slag were taken for analysis but the  results were unknown at the time of this paper's
  writing. A photograph of slag (from a later test) similar to that collected in P-2 is shown in
  figure 9.  The slag that has been collected to date appears to glassy in nature and well
  mixed. There have been problems with non-treated material passing through the throat, but
  this has been alleviated through a feeder modification.

MONITOR
02 (%)
CO2 (%)
NO* (ppm)
CO (ppm)
THC (ppm)
PCR-6, P-2 CEM RESULTS
1-MINMAX
15.5
18.0
7808
>10000
333
1-MINMIN
6.2
1.2
4315
176
48
1-MIN NORM
14.0
3.0
5000
230
60
 Table 3
CEM results from preliminary  test #2, performed  on April 25,
1989 using air as  a torch gas.	
 Supplemental 02 was added during feeding operation for the P-3 test. This resulted in
 higher normal levels of ©2 and CO2 and lower normal levels of CO and THC, as compared
 with P-2. NOx levels were about the same as in P-2, but higher than had been seen in
 previous tests with higher levels of organics. The SSM used in P-2&3 contained only  1%
 organics, not enough to have an impact on the NOX levels. This test consisted of feeding
 200 Ibs of SSM, which is not a large amount of material considering that the system had
 been drained the night before.  It was because of this that it was difficult to obtain a
 representative sample of slag from P-3; not enough material had been treated to obtain a
 good pour.

Preliminary results by Radian indicate that DRE's of 0.9999 to 0.99999 were obtained.
High levels of organics were found in the slag from P-3 due to untreated material being
thrown down the throat by the feeder. This was only discovered as a problem at the time
of the P-3 test (the feeder was subsequently modified).
                                      276

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PCR-6, P-3 CEM RESULTS
MONITOR
C>2 (%)
- CQz (%)
NOx (ppm)
CD (ppm)
THC (ppm)
1-MINMAX
18.4
9.8
6536
375
194
1-MINMIN
12.9
0.1
4652
17
16

1-MINNORM
17.5
0.2-4.0
5500
50
25
Table  4     CEM results from preliminary test #3, performed on April 26,
   	1989 using air as a torch gas.                     	
CONCLUSION

Based on the information gathered to date, the PCR project has reached some degree of
success. The major objectives of the system have been accomplished, in that heavy metals
and organic wastes have been treated with favorable results. Hydrocarbons have been
broken down and reacted with Oi to produce CO2 and FfeO. Molten slag has been poured
from the reactor and collected.  To date, all results indicate that these objectives have been
reached with a high degree of success.

Improvements will be made to this reactor (PCR-6) before the EPA SITE demonstration.
The seals around the copper throat will be improved. This will allow higher heat loads in
the area of the throat during feeding to insure total treatment of the toxic material.
Investigations are proceeding to increase  the power input into the melt chamber.
Modifications are being planned to enable higher feed rates (up  to 600 Ibs/hr). This will
require more advanced slag handling techniques to provide for increased amounts of molten
glass. Materials of construction for some components will be changed to resist the acidic
attack of the NOX and HC1.  Modifications to the scrubber system will be required to handle
the higher gas loads.
                                       277

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 FIGURE 8:  Photograph of PCR-6 melt chamber showing the extent of the
             molten  material.
FIGURE 9; Photograph of vitrified slag from local soil and 15% oil.
                                  278

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At this time the equipment is being disassembled and sent to Butte, MT. for a SITE
demonstration scheduled for the summer, 1989.  The feed for the demonstration tests will
be a mixture of mining wastes (soil containing heavy metals) and wood-treating waste oil
(containing pentachlorophenol and other components).  Feed rates of 100 Ibs/hr for 6
hours are to be performed for the SITE test. It is planned to operated the plasma torch with
air at power levels of 600 volts DC and 1000 amps. O2 will be added to both the primary
melt chamber and the secondary chambers during feeding operations. It is planned at this
time to feed at rates of 200 Ibs/hr for 30 minutes and treat the material for 30 minutes while
reloading the feeder, then feed again during the 6 hour period. Six hundred pounds of
material will be enough to produce a reasonable slag pour. Results from the demonstration
will be available in report form about six months after the three planned replicate runs are
made.

After the EPA SITE test, it is planned to continued operations in Butte under the direction
of the DOE to further evaluate the PCR. A separate program has been established for this
work. Optimum feed rates and power levels will be investigated during these tests on a
variety of materials.  The long term goals of the DOE are to process low level radioactive
wastes.  Efforts to implement this technology will be provided by personnel at the Idaho
National Engineering Laboratory (INEL).
          R. C. Eschenbach and K. D. Boomer, "Plasma Arc Stabilization of Hazardous
          Mixed Wastes", American Nuclear Society Winter Meeting, Los Angeles, CA.
          1987.
          J.W. Sears, R.A. Hill & R.C. Eschenbach, "Stabilization and Decomposition
          of Toxic and Radioactive Wastes by Transferred-Arc Plasma.", Incineration
          Conference  (8th  International  Conference  on Thermal Destruction of
          Hazardous, Radioactive, Infectious &Mixed Wastes), Knoxville, Tenn., May,
          1989.
                                     279

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                        HAZCON. INC.
         SUPERFUND INNOVATIVE TECHNOLOGY EVALUATION
                  'FINDINGS AND CONCLUSIONS

                  by:  Timothy E. Smith
                      HAZCON Engineering, Inc.
                      Brookshlre, Texas  77423

INTRODUCTION

     In October, 1987, the U.S. Environmental  Protection
Agency's.Offlees of Research and Development (ORD) and Solid
Waste and Energy Response (OSWER) Initiated their first test
of a sol Id'If Icatlon/stabI I Izatlon (s/s) process under the
Superfund Innovative Technology Evaluation (SITE) program.
The technology demonstration was developed by the .founders
of HAZCON, Inc., based In Texas.

     The HAZCON solidification process was selected for Its
potential  to effectively stabilize and solidify wastes
containing high concentrations of organic contaminants.
High organic wastes Inhibit the reaction mechanisms of most
s/s processes, and thus had rendered the technology non-
effective as a pretreatment alternative for land disposal of
these wastes.

     The major objective of the demonstration was to develop
reliable cost and performance data on the HAZCON process so
that It could be adequately considered In Superfund decision
making.  Evaluation criteria were established Jointly by the
EPA and HAZCON to evaluate the effectiveness of the process
In Immobilizing contaminants and In  Increasing matrix
Integrity.
                             280

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     The DouglassvlI Ie, Pennsylvania National Priority List
(NPL) Site, a former oil reprocess Ing fac11Ity, was selected
as the test site.  The site was placed on the NPL In 1985
due to the presence of high levels of organic and Inorganic
contaminants.  Contaminants Include PCB's,  heavy metals,
volatile and semlvolatlle organlcs,  base neutral acids and
other toxic materials.  An estimated 250,000 cubic yards of
material may be contaminated.

PROGRAM OBJECTIVES

     Five major objectives of the HAZCON SITE demonstration
were to determine the following:

          1.  Ability of the stabilization/solidification
              technology to Immobilize and  solidify the site
              contaminants.

          2.  Effectiveness of the technology In treating
              wastes with contaminant concentrations varying
              over the range 1-25% by wt. oil and grease.

          3.  Performance and reliability of the process
              system.

          4.  Long-term stability and Integrity of the
              sol Id If led mass.

          5.  Costs for applying the technology to
              commercial size or Superfund sites.
                             281

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METHODS AND MATERIALS

     Contaminated soils from the site were processed by
HAZCON's Mobil Field Blending Unit  (MFU).  The system  Is
truck mounted and typically used by HAZCON for small field
projects such as the SITE demonstration.  The system holds,
meters and homogenizes the waste feed with Portland cement,
Chloranan  (HAZCON's proprietary additive) and water.  The
processed material was then placed  In  1 cubic yard-sized
forms for curing.

     Samples were collected both before and after treatment.
These samples were subjected to an extensive testing
protocol, to Include TCLP leachate analysis, permeability,
weathering and strength tests, and mlcrostructuraI  analysis.
Materials from six plant areas were tested.  Each area
contained varying levels and types of contaminants across a
variety of waste matrices.  The following designations were
used to refer to the six plant areas:

          LAN     Lagoon Area North
          LFA     Landfarm Area
          PFA     Plant Processing Area
          DSA     Drum Storage Area
          FSA     Filter Cake Storage Area
          LAS     Lagoon Area South

     Five cubic yards of material  were processed from each
of the first five areas listed, twenty five cubic yards were
treated from Lagoon Area South (LAS).

     In order to effectively gauge HAZCON's claim to
Immobilize volatile organlcs, the  EPA requested permission
to Inject toluene at 125ppm Into the feed from DSA,  PFA, and
LFA.
                             282

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     Core samples were analyzed after 7 and 28-days of
curing.  These analysis were performed to determine the
effects of time and weathering on the mass.  This latter
series of tests provides additional  evidence of the long
term stab 11Ity of the HAZCON treatment process.
FINDINGS AND DISCUSSION

     The six test areas offered a wide diversity of waste.
The oil and grease ranged from \% by weight at the DSA to
25% at FSA.  PolychI or Inated blphenols (PCBs) were detected
up to 80 ppm by weight with the maximum concentration at
LAS.  Lead contamination concentration ranged up to 2.5% by
weight.  Volatlles and base neutral  acid extractable (BNAs -
semtvolat 11es) organlcs reached levels of about 100 ppm In
some areas.

     Permeabilities of the treated soil were very low, In
            —8      ~9                       •• 10
the range 10   to 10   cm/sec.  A value of 10    Is
generally considered an Indication of an Impermeable solid.
Unconflned compresslve strengths (UCS) ranged from about 200
psl for FSA to 1500 psl for PFA.  These values are quite
satisfactory from a load bearing point of view, I.e.,
equipment traffic.

     TCLP leaching tests, the results shown In Table 1 are
discussed below:

          Metals - the leachates for the solidified soils
          showed metal levels at or near the detection
          limits.  The results were a factor of 500 to 1000
          times better than the untreated leachates.
                             233

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                         TABLE 1.  RESULTS OF TCLP LEACHING TEST
                                         Leachate
Leachate





ro
00
.£»
Plant
Area
DSA
LAN
FSA
LFA
PFA
LAS
Soil Concentrat
Lead* VOC+
3,230
9,250
22,600
13,670
7,930
14,830
ND1
2
150
ND
0.4
6
Ions, ppm
BNA°
12
21
534**
37
18
40
Untreated Soil,
Lead VOC
1.5
33.
18.
28.
22.
53.
0.9§
0.03
1.03
5.90
1.80
0.07
mg/l
BNA
ND
1.02
2.86
0.01
0.01
0.01
Treat Soil - 7 days, mg/l
Lead VOC BNA
0.015
0.002
0.07
0.04
0.01
0.014
0.40
0.02
0.74
0.23
0.40
0.06
0.055
1.340
3.910
0.040
0.090
0.470
*   The great majority of the metals Is lead.

+   Primarily Toluene, trlchlorethene,  tetrachloroethene, ethylbenezene, xylenes.

0   Phthalates, phenols, naphthalene.

H   ND - not dlscernable

§   Toluene was Injected Into untreated soil  samples for DSA,  LFA,  and PFA before
    performing TCLP.  Concentration Injection equal  to level  measured In 7 day solids.

**  Very high In naphthalene and phenols.

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          Volatlles - the primary compounds detected were
          trJchloroethene, tetrachloroethene,  toluene and
          xylenes.  Only the leachates for the untreated
          soil  and 7-day cores were analyzed.   The levels of
          leachable contaminants were approximately 2 to 20
          times less In the treated materials  than the
          untreated leachates.

          BNAs - the compounds detected In the leachate were
          phthalates and phenols.  The phthalates were
          reduced to near their detection limits of .010
          mg/l  In both the treated and untreated soil
          leachates.  The total phenols In the leachates
          were In the range of .030 to 3.85 milligrams per
          liter, with the same concentration levels seen In
          both the untreated and treated soil  leachates.

          PCBs - were nonquantlflab Ie In the leachates.
CONCLUSIONS

     The following conclusions were drawn by the EPA and
their subcontractor Env Iresponse,  Inc.  upon reviewing the
data on the HAZCON process.  They  are:

     o  The process can solidify contaminated material  high
In organlcs.  Soils at the Doug IassvI I Ie Superfund site with
up to 25% organlcs were solidified.  Other applications
showed successful solidification of petroleum refinery waste
streams, organlcs, water high In organlcs from a waste
storage pond, metal finishing sludge,  and other less clearly
defined wastes.
                             285

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     o  Immobilization of heavy metals was observed,  with
leachate Improvements for lead and zinc In excess of  a
factor of 100.

     o  Organic contaminants, YOCs and BNAs, were hot
Immobilized for the most part.  The extensive testing for
the Demonstration Test and other test programs showed no
Immobilization of the organlcs.  However, there were  two
Instances where Immobilization of organlcs occurred.

     o  The physical properties of the treated wastes are In
general quite satisfactory.  High DCS, Iow permeabI I 11les,
and satisfactory results of weather tests were obtained.
However, large volume Increases In treated soils can  be
expected, and the mlcrostructural analyses of the solidified
soil materials Indicates a potential for  long-term
durability problems.

     o  Application for  Immobilization of heavy metals  (up
to 2.3? by wt.) In wastes containing high organlcs,  up to at
least 25% by wt oils, has been shown.  Successful
Immobilization of higher quantities of heavy metals at even
higher oil and grease levels would be anticipated.

     o   Immobilization of VOCs and BNAs did not occur In the
SITE Demonstration test  on soils up to 25% by wt oil  and
grease, and  Immobilization of other organlcs, as reported by
other  Investigators, was also unsuccessful.  However,
Immobilization of some petroleum refinery wastes was
successfuI.
                             286

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     o  Therefore, applications for Immobilizing organic
contaminants, compared to a s Imp Ie sol Id IfI cat Ion process
with only cementltlous materials,  may have to be tested on a
site-by-slte basis to prove applicability  of the HAZCON
process.  For high organic content wastes, solidification
may be very dIffIcuIt; the use of  Chloranan  will enhance
solidification of organlcs.

     The estimated cost for commercial scale application of
the HAZCON process was not reported In the Demonstration
Final  Report.  Iristead a figure of $205 per  ton of
contaminated soil  was reported, representing the estimated
per ton cost of the 50-cubIc yard  demonstration.  This Is
much higher than the normal $50 to $65 per ton costs HAZCON
has charged clients In the past for commercial scale
applIcatIon.

    One final observation made by  this writer during the
demonstration and subsequent Interpretation  of the data Is
that the use of EPA contracted support services In the
performance of this and other SITE evaluations may Introduce
an element of bias to the program.  An element which, either
for or against the demonstrated technology,  will distort the
true advantages and/or disadvantages of the  technology being
evaluated, thereby corroding the credibility of the entire
SITE program.  Inaccurate and misleading Interpretation of
the data from this test has been observed, and conclusions
have been pub I I shed wh Ich can not  be supported.  One EPA
contracted party Involved In this  evaluation now operates a
solidification/stabilization firm.
                            287

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                     REFERENCES

Sawyer, S« and dePercIn, P.  Volume 1, Technology
Evaluation Report SITE Program Test, HAZCON
Solidification Doug IassvlI Ie,  Pennsylvania;
EPA/540/5-89-001a, U.S. Environmental  Protection Agency,
Cincinnati, OH, 1989.

Final Draft Report: Sawyer, S. and dePercIn, P.  SITE
Program, Applications Analysis: Assessment of the
HAZCON, Inc. Solidification Technology.  U.S.
Environmental  Protection Agency,  Cincinnati, OH, 1989.
                        288

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     SITE:  Fixation of Organic and Inorganic Wastes/
                 Intimate Mixing Technique
                            by
    Carl L. Brassow, J. T. Healy and R. A. Bruckdorfer
                      Soliditech,  Inc.
                       Presented at

Forum on Innovative Hazardous Waste Treatment Technologies:
                Domestic and  International
                     Atlanta, Georgia
                     June 19-21, 1989
                            289

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                          ACKNOWLEDGMENT
Soliditech,   Inc.   would   like   to  express  its  thanks  and
acknowledge  the  help,  cooperation, suggestions and critique of
the  following  individuals:   Dr. Walter E. Grube, Jr., EPA SITE
program  manager  in the Risk Reduction Engineering Laboratory of
Cincinnati,  Ohio;  Dr.  Kenneth Partymiller of PRC Environmental
Management,   Inc;   Mr.  Robert  Soboleski  of  the  New  Jersey
Department  of  Environmental  Protection; Mr. George Kulick, Jr.
of  the Imperial Oil Coimpany; Mr. Robin Somerville of Solidwaste
Technology,  Inc.  of  Manhatten, Kansas; Dr. L. T. Fan, Chairman
of   the   Department   of  Chemical  Engineering,  Kansas  State
University  of Manhatten, Kansas; Dr. Danny Jackson and Ms. Debra
Bisson  of  Radian  Corporation,  Austin, Texas; Mr. Larry Malone
and  Arthur  Malone of Malone Service Company, Texas City, Texas;
and ENSR Corporation of Houston, Texas.
                               290

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           SITE:  Fixation of Organic and Inorganic Wastes/
                       Intimate Mixing Technique
           Carl L. Brassow,  J.  T. Healy and R. A. Burkdorfer
                            Soliditech,  Inc.
I.   INTRODUCTION

     Solidification/Stabilization    of    industrial   solid   waste,
     particularly  wastes  classified  as  hazardous  and  toxic under
     current   U.  S.  EPA  rules  and  regulations  is  a  developing
     technology.    Physical/chemical  processes  -involving the use of
     pozzolans  or  cements  with  the  addition  o£  various  special
     additives  are  the  most  prevalent.    These  processes  may be
     applied  to  the  waste  in-situ  or  the  waste  can be removed,
     treated,  mixed using an intimate mixing system and then replaced
     or  removed  to  another  repository.    The  Soliditech  process
     described  in  this  paper is an intimate mixing process based on
     the  use of pozzolans or cement and various additives, especially
     URRICHEM,   that   enhances   the ... ability  of  the  mixture  to
     incorporate  organic  compounds  into  the  matrix and reduce the
     potential for these compounds to leach from the mass.

II.  BACKGROUND INFORMATION

     Soliditech,  Inc.,  is a Houston, Texas based company established
     to  apply  the  solidification technology described herein to the
     remediation  and  cleanup  of  abandoned  disposal facilities and
     sites  and  to  the  treatment  of  currently  generated  wastes.
     Soliditech,  Inc. is a wholly owned subsidiary of United Resource
     Recovery,  Inc.,  which is a new waste disposal company that will
     incorporate  the  solidification  process at a new facility to be
     constructed in the near future.

     Soliditech  submitted the proposal to the U S. EPA to demonstrate
     the   technology   under   the  Superfund  Innovative  Technology
     Evaluation  (SITE)  program  in  1987.  The proposal was accepted
     and  ultimately a demonstration site selected which is located in
     New  Jersey.    The  site  is  the  Imperial  Oil Company site in
     Morganville,  New  Jersey,  some  twenty  or  thirty miles south,
     southeast  of  Newark.   The site has been in existence since the
     early  1900*s  and  has  been used for several purposes from food
     processing  to  recycling oil which is its current purpose.  (See
     Figure  1).    Various waste streams are present at the site most
     of  which  include some form of petroleum hydrocarbons in a matrix
     of soil, filter media or as a tank bottom sludge.

     The   field   demonstration  was  conducted  the  first  week  of
     December,  1988.    Three different waste streams were treated as
     part  of  the  demonstration  which  included a soil contaminated
     with  oily  sludge,  a  filter  media  with  a high percentage of
                                   291

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     hydrocarbons  and  an oily tank bottom sludge.  The latter stream
     was  co-treated  with  the filter media during the demonstration.
     A  total of fifteen yards of treated waste was collected, sampled
     and  tested.    The  waste was placed in plywood forms which were
     removed  after  28  days.    The  waste  blocks were stacked on a
     protective  sheet  of HDPE and covered with additional sheets for
     protection   and  storage  long  term.    Sampling,  testing  and
     observation of the blocks will continue for five years.

III. PROJECT DESIGN

     The  Soliditech  process  is designed to solidify waste materials
     by  mixing the wastes with a chemical reagent, various additives,
     and  pozzolanic  materials.    The following subsections describe
     the  Soliditech  process  chemistry,  treatment  process, and the
     main components of the process.

     Soliditech Technology

     The  Soliditech  process  solidifies wastes by use of UKRICHEM (a
     proprietary  chemical  reagent,  U.S. patent pending), additives,
     pozzolanic  solids,  and  water.    The  proportions  of reagent,
     additives,  and  pozzolan are optimized for each particular waste
     requiring   treatment.      The   solidified   material  displays
     properties  of  excellent  unconfined  compressive strength, high
     stability, and a rigid texture similar to that of concrete.

     The  waste  material  to  be  treated  is  first passed through a
     screen  with  4-by 4-inch openings to remove large rocks, debris,
     or  other  materials.  This screening step is performed to ensure
     that  laboratory  samples  do  not  include  large rocks.  During
     normal  operations,  only  very  large  material would be removed
     prior  to  treatment.    The  oversized material is collected and
     drummed  for  off-site  disposal.  Following screening, the waste
     material  to  be treated is placed in the Soliditech mixer, where
     the  reagent  and  other  additives  are dispersed throughout the
     waste  material.    The reagent and additives aid in the chemical
     and   physical   immobilization  of  the  hazardous  constituents
     contained  in  the waste.  It is sometimes necessary to add water
     to  the  waste  material to achieve the proper moisture level and
     to achieve uniform blending of the raw waste material.

     The  waste  mixture  is  then  blended with pozzolanic materials.
     Pozzolanic  materials  are  siliceous  or siliceous and aluminous
     materials   that   inherently   possess  oxides  (lime)  to  form
     compounds   possessing   cementitious   properties.    Pozzolanic
     materials  that may be used in the solidification process include
     Class  C  or  F  flyash,  cement kiln dust, slag cement, portland
     cement,  and  steel  baghouse  dust.  Depending on. the pozzolanic
     material  used,  calcium  oxide  (or  its  hydrated form, calcium
     hydroxide)  may have to be added to assure a hard set.  (Portland
     cement was used for the demonstration).
                                   292

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Hazardous  compounds  are  immobilized  by  one  or  more  of the
following   processes:      encapsulation,   adsorption,  and  or
incorporation  into  the  crystalline structure of the solidified
material.      The   waste  may  actually  penetrate  any  porous
structures  of the pozzolans as well as by bonding to the surface
of  the  pozzolans  by  either  ionic attraction or electrostatic
forces.

Water  contained  in  wastes  that  are treated by the Soliditech
process  and water added during the processing are involved in at
least two types of reactions.

    o  Hydration reactions

    o  Equilibration with the environment through evaporation

The  Paint  Filter  Liquids  Test  (SW-846, Method 9095, U.S. EPA
1986)  which Soliditech routinely performs has shown that no free
liquid remains once the solidification processing is complete.
As  each solidification mixture is optimized for a specific batch
of  waste material and because considerable variability can exist
between  types of pozzolans, each batch of treated waste material
    potentially  unique.    All  results  from this demonstration
is
should  be  considered  to reflect on the particular formulations
and pozzolans used for the demonstration.

Treatment Process

The  treatment  system  of the Soliditech process is presented in
Figure  2.    The  treatment  system, consists of a self-powered,
variable  speed  mixing  unit  mounted  on  a  low boy trailer, a
control  box  containing all mixer controls, a hoist to raise and
lower  the  mixing  unit,  a  vibrator to aid hopper clean out, a
liquid  reagent storage tank with a metered feed system, a hopper
for  storing  and  dispensing  the  pozzolanic  solids, tanks for
storing  process  water,  and  a  metered  gate  for  discharging
treated waste material.

Three   designated   waste  materials  were  treated  during  the
demonstration:    Off-Site  Area  1  (soil contaminated with oily
sludge,  Waste  Pile)  (filter cake) and the Abandoned Tank (oily
sludge).

For  Soliditech  demonstration  process,  a batch of contaminated
soil  from  Off-Site  Area One was collected, transported on-site
by  a  licensed solid waste transporter, sampled, and stored in a
lined  and  covered  dump  truck until it was to be treated.  The
waste   pile  material  was  sampled  immediately  prior  to  its
treatment.   Sludge from the abandoned storage tank was collected
and  sampled  prior  to  treatment and stored in 55-gallon drums.
                              293

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     Immediately    prior  to  treatment,  each batch of waste material
     from  Off-Site  Area  One and the waste pile filter material  was
     weighed  or  its  density  and volume measured and transferred to
     the  mixing  unit  by  a front-end loader.   Prior to treatment of
     the  mixture  of  sludge  and  waste   filter  material,  dry waste
     filter  material  was collected in a  front-end loader,  weighed or
     its  density  and volume measured, and placed in the mixing unit.
     The  weight  or  volume  and  density  of sludge in the drums was
     determined.   The drums of sludge were lifted and poured into the
     mixing  unit.    Adding  the  solid  waste  filter material first
     minimized splashing of the liquid waste.

     Once  the  contaminated  waste material was in the mixing unit,  a
     measured  volume  of  URRICHEM liquid reagent was pumped into the
     mixing  unit.    Additives  were measured and added to  the mixer.
     The  mixing  unit  was  turned  on and the URRICHEM and additives
     were  thoroughly blended into the waste.  When water was required
     for  the  mix, the amount was measured and pumped into  the mixing
     unit.

     After  the  waste  material,  reagent,  additives, and  water were
     thoroughly  blended,  the  volume  or mass of pozzolanic material
     was  determined  and,  as required, was added to the mixing unit.
     Mixing  requires  a  minimum of 20 to 30 minutes until  all of the
     ingredients  are  thoroughly  blended  into  a wet pasty mixture.
     The  mixing  unit  was lifted by its  hydraulic legs and the slide
     gate  operated  to dispense controlled quantities of the mix into
     the  larger  sample  containers and empty,  plastic-lined, plywood
     forms.    As  the  forms  were  filled,  samples  of the treated
     material were collected.

     After  each  demonstration  run  was  completed, the operation was
     shut  down  and  the process equipment was decontaminated using a
     high  pressure water and steam cleaner.  This water was collected
     and drummed for off-site treatment or disposal.

     Test  run  data including information on material usage, weights,
     volumes   and   all   operating  parameters,  were  recorded  and
     maintained  in  a field log by Soliditech personnel for each test
     run of waste processed.

     To  confirm  the  Soliditech  records,  EPA  kept similar records
     containing  similar information, as well as the time at which all
     operations  were  performed.    The  EPA run records included the
     results  of  the  particle  (sieve) size analysis for the treated
     material and the results of slump tests.

IV.  TEST RESULTS

     Three  types  of  waste material and  one control mix were treated
     as  part  of the demonstration.  The  control mix was a  mixture of
                                   294

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clean  sand,  concrete,  pozzolan (portland cement), URRICHEM and
other  additives  that were part of the waste stream formulation.
The  waste  streams  consisted of contaminated soil, waste filter
cake material and oily sludge.

Untreated  waste  samples  were collected for each test parameter
from  each  of  the  three  waste  streams.    These samples were
analyzed    for    total    chemical    constituents,    physical
characteristics   and   the   amount   of   solubles  removed  by
leaching/extractions.    The results allow a direct comparison of
physical   and   chemical  properties  between  the  treated  and
untreated  waste  and  a  determination  of  effectiveness of the
treatment process.

In  addition  to  discharging  the  treated  waste into large l -
cubic  yard plywood forms, numerous cylindrical sample containers
or  forms  were  filled with treated waste and allowed to cure 28
days.    After curing, the small sample cylinders were shipped to
the   laboratories  for  analysis.    The  final  product  was  a
monolithic  material  with  measurable  structural strength.  The
wooden  forms were removed and the waste monoliths were placed in
an  enclosed on-site storage area for long term monitoring.  Long
term   studies  will  include  a  six  month  leaching  test  and
performing  other  extraction  procedures  at various times up to
five years after treatment.

The  analyses  of the samples collected before, during, and after
the  Soliditech  demonstration  are summarized in Tables 1 and 2,
and discussed below:

o   Untreated  Waste  —  Untreated waste from the site consisted
    of  contaminated  soil,  filter  cake,  and  filter cake/oily
    sludge.    These  wastes  contained 2.8 to 17 percent oil and
    grease,   with   relatively   low  levels  of  other  organic
    compounds.    PCB  (Aroclors  1242  and  1260) concentrations
    ranged  from 28 to 43 ing/g; arsenic concentrations from 14 to
    94  mg/kg;  lead  concentrations  ranged  from  650  to 2,470
    mg/kg; and zinc concentrations from 26 to 151 mg/kg.

o   Treated   Waste   —  The  Soliditech  stabilization  process
    produced  solidified waste with high structural stability and
    low  permeability.    UCS  values ranged from 392 to 856 psi^
    Permeability  values  ranged  from  8.9  x 10~9 to 4.5 x 10~7
    cm/sec.    Because  of  the  cementitious  additives  in  the
    Soliditech  process,  pH  values  of  the  solidified  wastes
    ranged  from  11.7  to  12.0.   Arsenic concentrations ranged
    from  28  to  92  mg/kg;  lead concentrations from 480 to 850
    mg/kg;  zinc  concentrations  from  23  to  95 mg/kg; and PCB
     (Aroclors  1242  and  1260) concentrations from approximately
    15  to  41  mg/kg.  Low concentrations of phenol and p-cresol
                              295

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         were  found  in  solidified  filter cake and filter cake/oily
         waste  samples.    These  compounds  were not detected in the
         untreated wastes.

     o   Control  Mixture  —  The  control mixture contained 20 mg/kg
         lead.    PCBs,  phenols, and cresols were not detected in the
         control  mixture.    The reagents used for the solidification
         could  not  be  analyzed  for  phenol, o-cresol, and p-cresol
         because  of  the high alkalinity in the control samples.  Low
         levels  (0.06 ug/L, total) of volatile organic compounds were
         detected in the TCLP extract of the control mixture.

     o   Extract  of  Untreated  Waste — Arsenic, lead, and zinc were
         found  in EP, TCLP, and BET extracts of the untreated wastes.
         No  PCBs  were detected in the TCLP extracts of the untreated
         wastes.    Total concentrations of up to 1.3 mg/1 of volatile
         organic  compounds  and  up  to  0.38  mg/1  of  semivolatile
         organic  compounds  were  detected in the TCLP extract of the
         untreated  waste.    Oil  and grease concentrations of 1.4 to
         1.9  mg/1  were detected in the TCLP extract of the untreated
         waste.  Untreated wastes could not be tested by ANS 16.1.

     o   Extract  of Treated Waste — Significantly reduced amounts of
         metals  were  detected  in  the  TCLP,  EP,  BET and ANS 16.1
         extracts  of  the treated waste.  No PCBs or volatile organic
         compounds  were  detected  in the TCLP extract of the treated
         waste.    Phenol,  p-cresol, o-cresol, and 2,4-dimethylphenol
         were  detected  in  the  post-treatment  TCLP waste extracts.
         Oil  and  grease  concentrations  of  2.4  to  12.0 mg/1 were
         detected in the TCLP extracts.

V.   COSTS

     The  cost  elements  identified  in  the  demonstration provide a
     means  to  estimate the cost of solidification for a typical site
     remediation.    The actual costs of the demonstrations are biased
     when  reduced to a unit cost basis by the impact of mobilization,
     demobilization,  sampling  and testing, decontamination time, low
     utilization rates.

     Cost   elements  identified  in  the  demonstration  include  the
     following:
            Mobilization/demobilization of equipment
            Capital cost of equipment
            Cost of materials and additives
            Cost of labor
            Analytical expenses
            Health and safety training
            General overhead expenses
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     There  are  various  methods  of  applying  these  costs  to  any
     particular  project.     The  unit costs on the SITE demonstration
     would  be  extraordinarily  high  if  all  the  costs  were to be
     applied  to  the  approximate  15  cubic  yards  of waste treated
     during   the   5-day   demonstration  period.     As  a  point  of
     information,  this  cost  would  have  been  about $2700 per yard
     assuming  all pertinent costs were allocated to the treated waste
     volume.

     In  an actual field cleanup or remediation situation, many of the
     identified  costs would become insignificant when spread over the
     much  larger  volumes  of  waste  treated.    Assuming  that most
     factors  would  remain  relatively  constant,   that  the range of
     pozzolan  cost  was  between  $25/ton  and  $70/ton  and that the
     throughput  was  about 15 cubic yards and 30 cubic yards of waste
     per  hour, then the relative cost of the process would be between
     $46/yard  and  $75/yard  for  about 10,000 yards and $29/yard and
     $58/yard  for  about  100,000 yards of waste respectively.  These
     numbers  are for illustrative purposes only to reflect the impact
     of  waste  quantity  on  unit cost.  It is important to point out
     also  that  these costs do not reflect waste handling costs prior
     to  treatment  and  do  not  reflect  post-treatment handling and
     disposal costs.

VI.  CONCLUSIONS

     Conclusions  drawn  from  any  study  or  effort  are generally a
     combination  of objective results and subjective inferences based
     in part on these results.
     This   SITE
     following:
demonstration   was   conducted  to  determine  the
         The   effectiveness   of   the  technology  to
         stabilize waste materials found at the site.
                                      solidify  and
         The  ability of the solidified materials to maintain physical
         properties and structural stability over a five-year period.

         The  change  in volume and density of the solidified material
         after adding pozzolans, water, reagent, and other additives.
         Reliable   capital   and  operating
         Superfund decision making process.
                           costs  for  use  in  the
     The  results of this demonstration indicated that the process was
     effective  in  solidifying  and  stabilizing the waste streams on
     the  site.    The  data indicate some noteworthy effects of using
     additives   with   high   pH  values,  specifically,  1)  testing
     procedures  may need to be altered to accommodate pH range and 2)
     there  appears  to  be  an effect on phenols which are apparently
     selectively  leached  out  of the matrix.  Further study on these
     effects is currently being conducted.
                                   297

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The   range   of   unconfined   compressive   strengths  and  low
permeabilities   verify   the   solidification  objective.    The
objective  of  five years of testing hasn't been accomplished but
one  can  infer  that  concrete  is not likely to revert to basic
constituents  even  though  some  cracking or spalling may likely
happen.

The  change  in volume ranged from 0 to 60 percent but the median
appears  to  be  less  than  30  percent.    This is an important
parameter  when  estimating  disposal volume of treated waste and
this  level  is  probably an acceptable increase at this point in
time.

Capital  and  operating costs of an intimate mixing operation  or
technique  are  also  reasonable.    Any  treatment technology is
going  to  add  a  significant  cost to waste management over the
no-treatment  option.  The objective is to optimize the treatment
costs  consistent  with  the risk the untreated waste may pose in
the  future.    This  should  not  be  considered  as an isolated
parameter   but   rather   by  a  systems  approach  to  reducing
environmental risks for the future.

This  particular  demonstration  was  successful  in  meeting the
demonstration  objectives.   However, the SITE program itself has
certain goals, four of which are listed below:

o   To  identify  and  remove  impediments to the development and
    commercial use of alternate technologies.

o   To  conduct  a demonstration of the more promising innovative
    technologies  to  establish  reliable  performance  and  cost
    information    for    site   characterization   and   cleanup
    decision-making.

o   To   develop  procedures  and  policies  that  encourage  the
    selection  of  available  alternative  treatment  remedies at
    Superfund  sites  as well as other waste sites and commercial
    facilities.
    To  structure
    technologies.
a  development  program that nurtures emerging
For  the  most  part,  these  goals, as they were applied to this
project,  we  addressed  successfully.  Continued efforts must be
made   within   the   consultant  industry  and  the  "regulated"
community  to  promote  the  use  of these emerging technologies.
Satisfactory  approaches will not evolve if the program goals are
not applied.
                              298

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             DEMONSTRATION LOGISTICAL AREAS
               AT THE IMPERIAL OIL FACILITY
            ABANDONED STORAGE
                                                         LONG-TERM
                                                         MOMTOHMQAREA
        RAW POZZO.AN STORAGE
          UMT/WATER TRUCK
  VISITOR VIEWMQ AREA

   VISITOR ACCESS ROUTE

 \XSTAGMQAHEA
*T
 \  . PRC-EM TRAILER
                                                    IJ  \ MP0VAL CH. GUARD TRAUER
VM w* eomim CWM
                                                           PftlVATC HOMKS
                                                                    o
                           FIGURE  1


                                 299

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                         WATER
FRONT BUCKET LOADER
WITH BUCKET ABOVE
MIXER IN DUMP POSITION
                                                        SOUCHTECH, INC,
                                                    MORSANVILLE, NEW JERSEY
                                            I SOUD1TECH  PROCESSING EQUIPMENT
                                            OttATD: «/ll/li  REVUHZDl 1/15/11 j  JOJttCHJWO
                                             PRO  ENVIRONMENTAL MANAGEMENT. INC.
                        FIGURE 2
                                 300

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                                            TABLE 1

                                    PHYSICAL PROPERTIES
                                                Filter Cake/Oily
                                                 Sludge Mixture
      Filter Cake                Sludge Mixture               Off-Site Area One

Untreated     Treated3      Untreated     Treated"     Untreated      Treated*
 Bulk Density
   (g/cm3)
 Permeability
   (cm/sec)
 Unconfined
 Compressive
   Strength
     (psi)
    Loss of
    Ignition
   1.1
   NA
   53.7
 1.4
392
41.3
 1.2
 1.7
NA
70.0
856
34.0
                                                                           1.3
                                                                          NA
                                                                          36.3
 1.6
   NAb        4.5 x 10"7        NA        8.9 x 10"9       NA        3.4 x IO'8
677
33.7
Water Content      28.7
                                 21.0
                              58.1
Notes:

a      Treated waste sampled after a 28-day curing period.

b      NA = Not analyzed.
                            14.7
                            23.5
                            12.6
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                                                                          TABLE 2
                                                                 CHEMICAL PROPERTIES
                             Filler Cake
Chemical Untreated
Analysis8 Waste
pH 3.4
VOCsd NDe
SVOCs9 ND
PCBsh 28
Oil and Grease 170,000
Arsenic 26.4
CO
ro Lead 2,200
Zinc 26
Notes:
Lcacnate Uachate Lcachate Leachate ' Leachate
from from from . from from
Treated Untreated Treated Untreated Treated Untreated Treated Untreated Treated Untreated
Waste.0 Waste0 Waste0 Waste Waste" Wade0 Waste0 Waste Waste6 Waste0
n-8 4.6 10.8 3.6 12.0 4.8 11.6 7.9 12.0 5.1
ND 0.27f ND 50f ND 1.3f ND 10 ND 0.87f
3fif ND 1.2 63f 17f 0.38 0.97f 79f 16f 0.12f
16 ND ND 43 15 ^ ND ND 43 40 ND
77.000 U 4.4 130,000 60.000 1.6 2.4 28,000 46,000 1.9
28 0.005 ND 14 40 0.01 ND 94 92 0.20
680 4.3 0.002 2,500 850 5.4 0.01 650 480 0.50
23 0-30 ND 150 54 1.3 ND 120 95 0.60

Leachate
from
Treated
Waste0
11.5
ND
0.32f
ND
12
0.02
0.01
ND
Analyte concentration units for the untreated and treated waste are mg/Kg. Analyte concentration units for the leachate from untreated and treated waste arc mg/L
Treated wastes were sampled after a 28-day curing period.
0 Lcachate values
d VOCs
e ND
ThftSP. unliti»c rm
refer to results from TCLP test.
volatile organic compounds.
not detected.
• i i




        These values contain low levels of acetone, melhylene chloride, various phthalales, or other analytes which are commonly attributed to sampling or analytical
9       SVOCs  =
                                                                                                             contamination.
        PCBs
scmivolatilc organic compounds.
polychlorinated biphenyls.

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  ADVANCED CHEMICAL FIXATION
               of
ORGANICS and INORGANICS/IN-SITU
           TREATMENT
               By
       JEFFREY P. NEWTON
 INTERNATIONAL WASTE TECHNOLOGIES
         WICHITA, KANSAS
               303

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          INTERNATIONAL WASTE TECHNOLOGIES Inc.

Conceptual  Basis  of the Advanced  Chemical  Fixation (ACF)
Technology

Waste treatment techniques that are composed of Portland cement, fly-
ash, cement kiln dust, quick-lime, soil, clay, asphalt, sodium silicate,
slag, gypsum, etc., in various combinations for solidification/stabilization
(S/S) have been used for a number of years all over the world. Users
and suppliers of these technologies have in some cases also used the
term chemical  fixation (CF) to  define various compositions of these
materials, possibly with the addition of trace compounds  to accentuate
their effectiveness with certain waste types. Whatever the terminology
used, S/S or CF, particular compositions of these materials are the basis
of the proprietary treatment products on the market. Certainly one of
the major appeals  of this class of treatment technology is the relative
lower cost, if it is sufficiently effective for the waste types it is applied.
S/S has been viewed by many in the  environmental field as  a physical
or civil engineering process instead of a sophisticated chemical system.
Tests for the effectiveness  of treatment revolved around certain levels
of physical changes in the "ante et  post" treatment state."Successful"
treatments of some metals,  radioactive and non- radioactive, in certain
concentrations in sludges, soils, and liquids as measured by particular
light acid and water leach tests gave  additional marketing credence to
the notion that this was a  viable and effective treatment for a wide
range of waste types. Very little in-depth research of the chemistry and
physics of S/S and CF as it applies to complex or mixed wastes was done
because "it worked", as  determined by  certain  static and  dynamic.
deionized water leach tests. Also the use of the CF term with various
associated unsubstantiated or  stretched logic claims  as to a  given
product or compositions ability to treat a given waste effectively added
another level of apparent creditability. In parallel to the use of S/S over
the past few years  there has been a somewhat erratic or wandering but
yet  evolving regulatory  structure, influenced  by an  increasingly
negative and dubious public opinion of the true effectiveness of S/S and
CF  and  it's users. The environmentally  active and concerned  public
                           304

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elements, and to a increasing degree the regulatory authorities, saw no
true distinction between S/S and CF except marketing hyperbola. In
many groups, S/S and CF is viewed as  "low tech, no-tech, or pseudo-
tech" approaches to waste treatment. One important element needed to
solve the effectiveness issue are the questions  of what  comprises a
reasonable,  realistic, or necessary test procedures  of  S/S  and  CF
technologies and the "how clean is clean?" standards. The treatment
evaluation  methods and  standards for S/S and  CF  are a point of
contention  among the users and marketers of S/S and CF, competing
forms of treatment, the regulatory authorities, and the public.

In the midst of this complex  scenario we have been doing research into
the basic chemistry of chemical fixation of organics and inorganic toxic
contaminated soils, sludges, and liquids for the past few years.  We
believe the necessary reality of S/S or more appropriately defined  CF,
involve exceedingly complex  chemical mechanisms  and  phenomena.
And this class of technology should be evaluated on such terms as to its
true effectiveness.  One of the major objectives  of this article is to
develop a definitional separation between the nature of S/S  and CF
using the HWT-20 Series ( Patent Pending. IWT) compositions as  the
prototype of a new ACF class of treatment technology. In that regard we
will review GC/MS readings of acid leach and solvent extraction tests of
cases involving soils  contaminated with PCBs and other high content
mixtures of organics treated with the International Waste Technologies
(IWT), HWT-20 Series Products. A recently discovered problem with
high content organic wastes  treated with a typical S/S mixture using a
quick-lime.pozzo Ian base will toe discussed. We have also used infrared
adsorption (FTIR) and differential scanning calorimetry  (DSC) to give
insights into the chemical bonding mechanisms of this particular type of
ACF technology with a range of organic compounds in a pure liquid or
contaminated soil form.  It would be wise at  this point to give some
background information relative to the chemical design and analytical
thinking that went into  the HWT-20 ACF  prototype. As was  implied
earlier we believe that S/S and  CF should be based on an accurate
paradigm of the chemical process rather than a adsorption/dilution
panacea judged effective by weak arguments of diffusion  potential  and
                           305

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 end-state  physical characteristics  of questionable relevance  and
 validity. Our position is that the extent and  strength of the chemical
 bonding and alteration to innocuous forms within the treated matrix is a
 truer measure on the short and long term effectiveness of this category
 or form of treatment.

 Chemistry Overview

 This HWT  ACF technology is  based on three sets of interrelated
 functional  chemical groups. There  is  a cement  matrix  chemistry,
 organophilic linking mechanisms, and a free radical and  ion attack
 mode.  The underlying   concepts   have  been discussed  in  some
 intermediate level  of  detail by us in previous papers, so we  will
 summarize this time.

 Matrix Cement Chemistry: The objective of the cement chemistry is not
 primarily end-state physical  properties but  to facilitate the overall
 objective of bonding  the toxic  molecules and ions  within a given
 contaminated material. In line with that point certain aspects of the
 cement hydration reaction (CHR) are altered and stretched out in time,
 the fibrils (sulpho-ferri-hydrates) that exist in the second stage of the
 CHR are modified to be more chemically reactive, and caused to be more
 dense. Certain admixtures are used to to cause a greater dispersion of
 the cement particles  in impure environments which   in turn  will
 promote  better  development of  the  weak   IPN  (Interpenetrating
 Polymer Network)  bonding function.  This  function is the slowest
 reaction of all three functional groups and its primary function is to be
 the silicate anchor matrix to which all other reaction products attach.

Free Radical and Ion Attack Chemistry  This is a parallel chemistry
that can be made up of a wide range of compounds that produce highly
reactive ions and complexes in the HWT-20 slurry. This  activity does
not interfere with the functioning of the other major functional CF
groups. This chemical function should attack various toxic organic and
inorganic elements within the contaminated medium and  reduce them
to relatively inert forms or reaction products  that can  subsequently
                           306

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react  with one of  the  other  functional groups  in  the  HWT-20 ACF
material. A simple example of this capability is the use of transition
metal complexes, but even these must be thought out carefully for one
could cause certain counterproductive reactions.  An example of this is
shown in Figure 2, Coordination Complexes, and  an explanation of the
bonding is given in Figure 3.

Organoohiiic Linking Mechanisms  These are  intercalation compounds,
such as modified smectite clays, that interact with the organics present,
within certain ranges of predetermined  selectivity,  by a sorptive
process in either of two general modes. The strong, short range bonding
is based on a Bronsted and or Lewis acid or base reaction, see Figure 4
relative to such a reaction we have observed with triethanolamine. The
weak, long range forces  are  basically hydrogen bonds, see Figure 1
induced dipole or Vanderwaals forces. There can be an initial reaction
based on the weak force  reaction and later a second strong or Lewis
basereaction.

These  modified smectite clays  have both organic and   inorganic
properties due to the substitution in the normally inorganic clay
structure of the Group  IA  and  IIA metal  ions  that  present with
quarternary   ammonium  ions.  This  makes   them   ideal  linking
mechanisms between the toxic organics in the waste and the cement
matrix.The introduction of the quarternary ammonium ions also opens
the basal spaces in a pillaring effect to allow like polarity organics into
the strong force reaction zone. Bonds can range from weak Vanderwaal
forces to strong co-ord inate covalent bonds.

The  important point  is  that  this  is   primarily a problem  in
supramolecular chemistry and that multiple and  secondary bonding
and positioning of the appropriate molecular structures is the key issue.
The individual FTIR shifts on functional groups seen are usually not
considered large and in some cases are slight, but the number of bonds,
the sum of the shifts,  and the positioning of the bonds is a stronger
effect in most cases one would see in a primary bond. An indicationof
the strength of this multiple and  secondary bonding phenomena can be
                           307

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 seen in "Percentage Increase in Energy" of the DSC analysis of a given
 waste. ( Figure 4 ). We have also done DSC studies on the treatment of
 pure  phenol, nitrobenzene,  and  trichloroethylene  and  achieved
 percentage energy increases of 220.7,  275.9, and 52.8 respectively. An
 significantadjunctcondition is that the behavior of a pure substance in
 a laboratory gives one an idea of what is possible but in a real, complex
 waste many other factors will interfere with the ACF material chemistry
 in achieving the maximum desired effect.  There are some positive
 assisting factors but in most cases one must design ACF materials  to
 overcome a variety of chemical hurdles before the fixation reaction can
 reach the desired level of  efficiency. The  use of advanced  chemical
 techniques and analysis provide invaluable  insights into the waste
 chemical mechanisms.

 Fourier Transform Infra Red (FTIR) FTIR studies are used to understand
 the extent of interaction between the toxic compounds and the HWT-20
 ACF  material. This  analytic  technique measures  the  changes  in
 vibrational motion in specific  bond relationships. It also  helps to
 determine the functional elements present  in a given molecule and
 involved in a bonding process.

 DifferentialScanningCalorimetrv(DSC) DSC measures the changes in
 temperature and energies associated with various significant chemical
 changes involved  in bonding,  such as the  dH of  melting,  dH  of
 evaporation,  dH of decomposition,  dH of phase  transition, etc. This
 technique can indicate the strength of bonding.
OVERVIEW of IW-S1T1J APPLICATION

The application of the ACF technology can take place above ground level
using a variety of mixing systems or in the ground, in-situ, as was done
at the former General Electric transformer repair facility site in Miami,
Florida. The use of high and or low pressure, rotary shaft injection with
or without mechanical blade mixing has been done for more than ten to
fifteen years in the construction industry for creating injection piles and

                          308

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sub-surface barriers. It was a natural extension of this construction
method  to be  used  in  the treatment  of contaminated  soils  and
sediments, if one had a cement chemistry that would  prevent both
inorganics and organics from leaching at an unacceptable level. The low
pressure, rotary shaft injection and blade mixing equipment offered by
Geo-Con^ Inc. was chosen because it would give an  even, homogeneous
blending of the HWT-20  ACF with  the  soil and  subsurface porous
limestone strata encountered at the site and create accurately placed.
overlapping columns the entire  length of the column. An additional
purpose  of the in-situ  method  other  than the  fact it  treats the
contaminated soil in-place is that GE was interested  in using this
technique of application  in sites where there was volatile and semi-
volatile organic contamination of the subsurface soils where  it would
not be desirable to expose these soils to the air by a removal technique.

At the SITE'S Program Demonstration Geo-Con used a relatively small
diameter drill, one yard, for two reasons. The drilling for most of the
time was in rock and the objective was to prove the concept of in-situ
treatment. The mixing drill process could be operated in sand/clay soils
with a larger diameter drill ( 2 to 3 yards ) and  or multiple.parallel
drills, up to  four  shafts  quicker and  more  economically.  In-situ
treatment costs can be as  low as $20 to 30/yard,  excluding treatment
chemicals, on a large project, up to $60 to70/yard in difficult situations.

PCB LEACHING and EXTRACTION STUDIES

The HWT-20 CF Series was successfully used in the treatment of PCBs at
the General Electric (GE) Miami Site under  the  U.S. Environmental
Protection Agency's Superfund Innovative Technology Evaluation (SITE)
Program. This application was done in-situ using mixing drills down to
6.15  meters from Geo-Con, Pittsburgh. The first  1.2  m was sand, the
second 2.5 m was a porous coral like limestone, and below that  quartz
sand, with fresh water at 1.2 m. The level of addition of the HWT-20 CF
material was 15% by weight to soil. In other words  for every metric ton
of contaminated soil 150 kg of dry HWT-20 was added in a slurry form.
The  maximum concentration  of PCB was 5700  ppm.  The  leaching
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 procedure was  the USEPA TCLP (Toxicity Characteristic Leaching
 Procedure), 18 hour dynamic acetic acid test. ANS 16.1, and the MCC-1
 leach procedure. Essentially no PCBs came out in the EPA testing and
 only one sample was found to leach in GE's testing and that was 1.2 ppb
 on a two week old sample. GE did methylene chloride extractions of drill
 core samples as well and did not find in excess of 206 ppm PCBs in the
 treated samp les us ing GC/ECD.

 In some pre-project laboratory experiments carried out by Dr.  R.
 Soundararajan gave some insights into what was occurring  in the
 treated soil matrix. In a sample of similar type PCB contaminated soil,
 eight-hour  methylene  chloride  extractions were performed on the
 untreated and crushed treated samples.

 Analysis was done by GC/MS with the machine calibrated against all
 221  position isomers of PCBs. In one sample of this experiment an
 admixture was included that produced a sulfurous acid that would
 totally disable the organophilie clay linking mechanisms between the
 PCBs and the slower developing silicate based anchoring matrix. In the
 second  sample the admixture was removed  so  the primary linking
 mechanisms could function.

 The results are as follows, untreated soil released 28,800 ppm PCBs in a
 methylene chloride extraction.
              Sample 1: Admixture        Sample 2: No Admixture
 Treated Extraction      26,437 ppm              2,800 ppm
 Treated TCLP           10.437 ppm                12.5 ppm

 These tests were done only three days after treatment. A treatment
 dilution factor of 20% is included in above numbers. TCLP numbers did
 improve with the age of treated sample. This particular sample showed
 only a 5-6,000 ppm value using standard GC/ECD  analysis mainly
 because  the GC/MS could sort out all 221  PCB isomers. Also high
values(40-50,000 ppm) of chlorinated benzenes were found, most likely
 the decomposition products of the PCBs, since no chlorinated benzenes
were ever used at the site. They were reduced in a similar proportion to
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the reduction in PCBs of Sample 2 from untreated to treated extraction
values. Almost all the existing PCB isomers after treatment were the low
value chlorine forms.

The conclusions of the above experiment were supported further in
another set of leach and extraction tests performed on a sample of a
clay/sand soil contaminated with low  levels of PCBs(290 ppm).  The
testing procedure was the same as above  with the focus on which
isomers were bonded or  retained  in  the  treatment matrix after a
solvent extraction of crushed treated samples for eight hours. The TCLP
leach tests of the treated material were all non-detectable. The sample
cured for seven days. The  treatment  level of HWT-20 was  15%  by
weight to the weight of  soil.  In the untreated soil there was some
chlorobenzenes and substituted phenols but none were found in the
treated. Only the lighter PCB isomers (tri.tetra, and  penta ) were found
in the treated. The hexa and heptachlorophenols were not found in the
treated. The total PCB content extracted was  190 ppm or 65%.

Relative to PCBs the current HWT ACF  treatment technology is able to
alter or bond to  a high degree the heavier chlorinated PCB molecules
and a lessor degree the lighter  chlorinated molecules. It is  very
effective in preventing  the leaching of PCBs against the TCLP of all
types. Also the HWT-20 ACF treatment sufficiently bonds and prevents
the leaching of the PCB decomposition products,  substituted benzene
and phenols compounds. Newer formulations of a more  advanced  IWT
ACF product show significantly greater rates of bonding or chemical
alteration of organics including PCBs. An example of the treatment of  a
PCB containing waste with our newer "Polyfunctional Reactive Silicates"
(PFRS) (TM) is shown in Figures 5 and 6. These ACF materials are based
on new inorganic carceplex structures  and heretofore non-existent
organic trailers. As the results are shown  it is are most effective PCB
reaction to date and the research is continuing to be positive. The first
of these new PFRS materials should be commercially available later this
year.
                            311

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Treatment bv ACF of High Content Organic Waste

An organic content waste with a high percentage of heavy hydrocarbons
with relative trace to small fractional  loadings of volatile and  semi-
volatile toxic compounds is normally a  difficult material for the usual
S/S mixtures to effectively treat unless some integer multiple by weight
of the S/S material is added to the weight of the waste and end-state
physical properties are all that is being considered. The waste sample in
this  case was a  soil  with a  heavy concentration of long  chain
hydrocarbons from a acid/clay process for recycling used oil. The major
organic toxic components of this waste as determined by  a solvent
extraction and analyzed by a GC/MS were the following:

                    Untreated Extraction Treated Extraction  TCLP
 Bis(l-chloro iso propyl) ether   8.528  ppm       ND           ND
 Naphthalene                  18,060  ppm       1445 ppm     ND
 Phenanthrene                 20,184  ppm       ND           ND
 Benzo (A) anthracene          30,460 ppm       ND           ND

This  contaminated sample was  treated 50%  by  weight  with a
experimental and more advanced CF  material and allowed to cure for
only two days. This treatment level  is too high for an actual project but
what we were trying to achieve is an accelerated effect that would
allow us to examine the  bonding activity  more quickly by the solvent
extraction (GC/ MS), FTIR, and DSC analysis. A dilution factor of 50%  was
used in all quantitation.  Standard methods of analysis and QA/QC were
used.

With such a complex mixture to analyze by FTIR and DSC the approach
has to be different then working with a pure known organic liquid.  In
using FTIR we focused on functional groups that we knew were there in
relatively large concentrations and looked for shifts within those groups
to indicate a level of bonding activity. In reviewing the data we have
found that there were significant shifts in a number of FTIR frequency
regions, hydrogen bonding was occurring between the aliphatic amines.
hydroxy compounds, and the oxygens  in A12O3 and Si02 in the CF
                          312

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material. There was a amine salt formation as the result of a Lewis base
reaction at 1580 cm-1. The most significant shift occurred at 1005 cm-1
where a hydrogen bond was formed with an Si02. This is explained by
the fact that  the  oxygens off the silica strongly  interact with the
hydrogens of alkyl,  hydroxyl, and ami no  groups which results in a
reduction of the 0-Si-O bond order. (Table 1, Infrared Data)

The DSC data (Table 2, DSC Data) also confirms that relatively significant
bond ing activity is occurring. The dH of vaporization has increased by
54.9%  from untreated  to  treated.  The DSC analysis  is  a energy
summation function rather than a focus on a specific reaction.

Recent experimental work done by Dr. R. Soundararajan has  indicated
that lime, lime/fly-ash, or pozzolan based S/S of organic content waste
of a sufficient level, what this threshold  is  is not  known  yet, but
certainly the oil recycling waste in this case applies, will  generate
significant carbon monoxide  and or  acetylene gas when exposed  to
water  of even  mild acidity.  Also during the process of S/S or CF
treatment it is desirable to keep the heat generation by the reaction
with water as low as possible since the more heat generated the more
the volatilization of the organics. The  IWT ACF technology  does not
contain but trace amounts of lime in the cement used in a fraction of it's
composition and  no pozzolans are used.  The rate of addition of the IWT
ACF materials used to weight of waste is relatively low, 12 to 20%, and
has a lower heat of hydration than straight cement.

Summation

Chemical fixation technology  is far more advanced  and cost/effective
than most people realize, especially from  those companies or groups
that have done in-depth chemical research of the basic fixation reaction
mechanisms.  International  Waste Technologies has and is doing  this
basic research and believes that the HWT ACF Product Series and the
new, more advanced products, PFRS, that  will come  out  in  the near
future will compete favorably with thermal and biological methods  in
the destruction, alteration,   and  or bonding of  organics  and  the
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 immobilization of inorganics. The effectiveness of ACF technology can be
 verified analytically with relative quickness and  function in a wide
 range of contamination environments at relatively acceptable costs and
 ease of use factors. An important key to the success of this category of
 toxic waste treatment is for the regulators and users  of this type of
 technology insist on high standards of relevant chemical testing and
 verification in the pre-project treatability analysis and careful QA/QC
 during project application.

 In-situ applications  that are effective in terms of their homogeneity of
 mixing of the ACF material with the contaminated soil to the required
 level  and do not leave any voids can be an effective, economical, and
 necessary part of  the waste treatment picture. The Geo-Con system
 successfully demonstrated that objective.

 Copyright
J. P.  Newton - June 7. 1989
International Waste Technologies. Inc.
 150 North  Main-Suite 910
Wichita. Kansas 67202
316-269-2660. Fax-316-269-3865
                         314

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TABLE 1
INFRARED DATA

Waste
Extract
cm-1
3394
3382
3373
1597
1035

Waste
Extract + Binder
cm-1
3385
3372
3355
1580
1005
Infrared
Frequency
Shift
cm-1
-9
-10
-18
-17
-30
Infrared
Functional
Group
Assignments
OH Stretch O- - -H....O
NH Stretch N- - -H....O

Keto group C --"O....H
Hydrogen Bonding Si Si
                                   \/
                                    O
                                    H

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                                                 TABLE 2
                                                  DSC DATA
               Waste Extract
               Waste Extract + Binder
DSC Endothermic Peak Values

                Temperature
                (Degrees C)

                138.90

                121.2
                414.4
                414.5
 H (Vaporization)
Cal. per gram

18.63

 6.15
 2.32
 2.06
                                                                             10.53 Total
CO
I—>
CTl
               Total  H (Vaporization)

               Total  H (Vaporization)
               corrected to 100%
               Waste Extract
               Cal/gram

                 18.63
Waste Extract
+ Binder
Cal/gram

  10.53

  28.65
    TGA - Percent wt. loss at
    given temperature range
                                                                        Waste Extract + Binder
                                    36.48
    PERCENT INCRESE in  H (Vaporization)
    for Waste Extract + Binder
                                     54.9

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               FIGURE 1
   Observed Bonding Phenomenon
   in the HWT-23 Treatment Matrix
   Hydrogen Bonding of Phenol Molecules
      Oxygen
          ,o
       H-
          •o
     \
o^,
o'
H
    Oxygen
                Aluminum
                Oxide Layer
                 Phenol Molecules
                    Silicon Dioxide
                    Layer
   Evidence:
   Lowering of FTIR Stretching Frequency
 Phenol
962 cm 1
3640 cm -1
    Treated Phenol
       934 cm 1
      3632 cm1
                    317
             Shift
             -28cm1
             -8 cm 1
Peak Assignment
   C-O
H - bonded OH

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                FIGURE 2
         Coordination Complexes
             3+
6 (C6 H5 OH) + M(Transition
                               (C6 H5 OH)
               CfiHsOH


                         Octahedral Phenol
                         Metal Complex
C6HSOH Q^^	
                M+-\
C.H.OH
              \

                      X
                     XC6H5OH
               C6HSOH
  Evidence:
  UV - Visible Spectra - Drastic Color Change
                    318

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             FIGURE 3
         PIT to dor Bonding
                  TT Electron charge clouds
                 Metal dir orbitals (empty
                 or partially filled orbitals)
Evidence:
Shift in FTIR Frequency for Ring Breathing
                  319

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                    FIGURE 4
         Lewis Acid  Base Reactions:
       Formation of Sigma Bonds (a)
                        Aluminum Oxide Layer
FTIR ANALYSIS
Triethanolamine
2104
1075
Treated
2297
1070
Shift
193
-5
Peak
Assignment
Amine Salt
Formation
H bonding
                        Silicon Dioxide Layer
  X = Electron deficient species or H+which is
  a Lewis Acid. Evidence:  Shift in N - R (n)
  frequency in positive direction (increase)
Edotherms
  (°C)

 150.97
 337.30
   DSC ANALYSIS - TRIETHANOLAMINE

   Hof
vaporization  Observed H of  Percentage   Boiling
 (literature)   vaporization   Increase in   point
 Kcal/mol     Kcal/mol     energy    (°C)
12.78
            24.16
89.0
335.4
                                   Highest
                                  endotnermic
                                  temperature
337.30
                        320

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              FIGURE 5
Formation of Permanent O-+TT Bonding
          (Covalent Bonding)	
  A = O +  H2X
ACF Material   Toxic
           Waste
                                H,O
                     Irreversibly Bonded
                        End Product
                   321

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                   FIGURE 6
         Supramolecular Chemistry/
     Multiple and Secondary Bonding
                Dichlorobiphenyl
                    AI2O3 Layer     Q     O
                  O     O
                 Solvent Extraction and Leach Results:
PCB
Untreated
 (ppm)
 17,580
                 Solvent Extraction of Treated (ppm)
N.D.
         TCLP

         N.D.
 Dichlorbiphenyi
   1150cm-1
                  FTIR Study of PCB
            Treated PCB
             1118cm1
  Shift
   -32
 *U,S,COVERNMENT PRINTING OFFICE: 1990-7*8- 1 5?0 0 ts 2
                         322
Peak Assignment
    CjtoAl
Coordinate Bond

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