EPA/540/5-90/004
DEVELOPMENT OF ELECTRO-ACOUSTIC SOIL DECONTAMINATION (BSD)
              PROCESS FOR IN SITU APPLICATIONS
                            by
      H. S. Muralidhara,  B.  F, Jirjis, F,  B.  Stulen,
     G. B. Wickramanayake,  A. Gill,  and R. E. Hinchee
                         Battelle
                      505 King Avenue
                   Columbus, Ohio 43201
                     January  18,  1990
                      Project  Officer

                     Ms. Diana Guzman

            Office of Research and Development
    Superfund Innovative Technology Evaluation  Program
           U.S. Environmental Protection Agency
             26 West Martin Luther King Drive
                  Cincinnati, Ohio 45268

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                              NOTICE
     The information in this  document  has been  funded by the U. S.
Environmental Protection  Agency under Cooperative  Agreement  No.
815324-01-0  and the Superfund Innovative  Technology Evaluation
 (SITE)  Program.  It has  been subjected  to  the Agency's  peer  review
and administrative review  and it has been approved for publication
as a U. S.  EPA document.    Mention of trade names or commercial
products does not constitute an endorsement  or recommendation  for
use.
                                11

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                            FOREWORD
     Today's  rapidly developing and changing  technologies and
industrial products and practices frequently carry with  them the
increased generation  of materials  that,  if improperly  dealt with,
can threaten  both public health and the  environment.  The U.  S.
Environmental Protection Agency is charged  by Congress with
protecting the Nation's land, air, and water resources.   Under  a
mandate of national  environmental laws,  the agency strives to
formulate and implement  actions  leading to a compatible  balance
between human activities and the  ability  of natural resources to
support and nurture life.   These laws direct the EPA  to perform
research  to  define  our  environmental problems,  measure  the  impacts,
and search for solutions.

     The Risk Reduction Engineering Laboratory  is responsible for
planning,   implementing and managing  research,   development, and
demonstration programs to provide an authoritative, defensible
engineering basis in support of the policies,   programs and
regulations of the EPA  with respect to drinking  water,  wastewater,
pesticides,   toxic substances,   solid and hazardous wastes,  and
Superfund-related  activities.  This  publication is one of the
products of that research and provides a vital  communication link
between the researcher  and the  user community.

     An  area  of  major   concern is  the environmental  impacts
associated with sites  contaminated with  nonagueous phase liquids
and heavy metals.  Because increasing proliferation of  these wastes,
contamination of the ground  and groundwater  at  a  number of
locations is  causing a serious threat to  the environment. Hence,
the U.  S.  Environmental Protection Agency  awarded  this SITE Program
Cooperative Agreement to investigate the technical feasibility of
the electro-acoustic soil decontamination  concept.  This report
presents and  discusses the  development program  which  included  a
literature review, soil characterization,  design and construction
of  a  laboratory unit,  and lab-scale experiments with soils
contaminated with         and inorganic  contaminants.
                           E. Timothy Oppelt, Director
                           Risk Reduction Engineering Laboratory
                               111

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                                   ABSTRACT

          The technical feasibility of the electro-acoustic soil
decontamination (ESD) process through laboratory experiments clearly
demonstrated the removal/concentration of heavy metals such as cadmium and
zinc.  Results of the decane contaminated soils were, however, inconclusive.
          The ESD process is based on the application of a d.c. electric field
and acoustic field in the presence of a conventional hydraulic gradient to
contaminated soils to enhance the transport of liquid and metal ions through
the soils.  Electrodes (one or more anodes and a cathode) and an acoustic
source were placed in contaminated soils to apply an electric field and an
acoustic field to the soil.  This process works especially well with clay-
type soils having small pores or capillaries, where hydraulic permeability is
very low.
          The development program included a literature review, soil
characterization, design and construction of the laboratory ESD unit, and lab-
scale experiments with soils contaminated with decane, zinc, and cadmium.
Evaluation of the experimental results clearly indicated that application of
the field forces reduced the heavy metals zinc and cadmium more than 90
percent in the treated cake.  A maximum of 97.4 percent concentration
reduction in cadmium was achieved, and 92.3 percent concentration reduction in
zinc was obtained.  Tests yielded 10-20 percent decane removal.  The results
on the decane contaminated soil were inconclusive as a result of the large
discrepancy in the decane laboratory analysis.
                                      IV

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                                    CONTENTS
Figures	     vii
Tables	      ix
List of Abbreviations	     xj
Acknowledgement            	    xii
     1.    Introduction  :	      1
     2.    Background	      3
                Electra-kinetic Phenomena  Principles.  	     10
                     Electra-osmosis	     10
                     Current Flow	     14
                     Ion Migration	     14
                     Ion Diffusion	     15
                     Joule's Heating	     15
                     Electrolysis  	     16
                Acoustic Phenomena  Principles  	     16
                Combined Electra-acoustic  Separation Principles  	     18
     3.    Project  Planning  	     21
                Quality Assurance  Project  Plan.  	     21
                Material Selection  and  Characterization ....  	     22
                     Soil Types	     22
                     Organic and  Inorganic Contaminants 	     22
                     Electrical and Acoustical  Properties  	     23
                Experimental Investigation	     23
                     Preparation of Soils  	     23
                     Bench Scale Study with  a  Test Unit	     23
                          Acoustic  Energy  	     25
                          Moisture  Content	     25
                          Treatment Duration	     25
                          ESD  Tests on Oecane	     25
                          ESD  Tests on Zinc	     26
     4.    Experimental  Investigation  	     28
                Material Selection and  Characterization 	     28
                          Soil  Preparation	     28
                          Decane Soil  Preparation 	     28
                          Zinc  Soil Preparation	     31
                          Zinc-Cadmium Soil  Preparation 	
                Test Unit Design and  Instrumentation.	     3:
                     Test Cell	    39
                          Decane Test Cell.   	    39
                          Zinc  Test Cell.   	    39
                Experimental Procedures  -----------------    41
                Analytical  Procedures  	     43
     5.    Experimental Results 	     45
                Decane  Experimental Results  	     45

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                                    CONTENTS
                                   (Continued)


                     Initial  Decane Concentration  	    45
                     Effect  of Electric Field on Decane Mobility	    47
                     Effect  of Electric Field and  Time  on Decane  Removal .   47
                     Effect  of Electric  Field on  Soil  Moisture Content  ..   49
                     Effect  of Acoustic Field	   49
                     Statistical Analysis on Tests 26D-30D	    51
                     QC Assurance  of  Analytical Data:  Decane.  ______    54
               Zinc  Tests   	   59
                     Results  of Zinc Tests	   59
                     Background on Electra-chemical Reactions  of  Zinc
                          at the Electrode	   59
                     Effect  of Time on Zinc Removal	   60
                     Effect  of Average Power on Zinc Removal	   66
                     Effect  of Acoustic Power and  Frequency
                          on Zinc Removal	   70
               Zinc/Cadmium  Test	   75
               Quality Assurance of Analytical  Data:  Zinc and Cadmium.  .    78
                     QC Data for Zinc  and Cadmium	   84
                Internal  and External  Quality Assurance Audits 	   84
     6.    Technical  Performance of BSD with Other In-Situ Technologies. .   88
                     Organics Treatment	   88
                     Pump and Treat	   88
                     Soil Venting	   91
                     Heat Enhances Soil Venting	   91
                     Steam  Injection	   92
                     Radio  Frequency Heating 	   92
                     Direct  Current Heating	   92
                     In-Situ Vitrification  	   92
                     Biodegradation	   93
               Meterials Treatment	•	   93
                     Direct  Current	   93
                     Pump and Treat	   93
                     In-Situ Vitrification  	   94
     7.   Conclusions	   95
     8.   Recommendations	    96
     9.    References	   97
Appendices
     A.    Decane Data   	A-l
     B.   Zinc Data	   B-l
     C.   Geochemical  Calculations  for Zinc Soil.  •  •	C-l
     D.    Zinc/Cadmium  Data	D-l
     E.    Geochemical  Calculation  for  Zinc Cadmium Soil	E-l

                                       vi

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                                  FIGURES

Number                                                                Page

  1 Conceptual  Layout of Electra-acoustic  Soil Decontamination	   4
  2 Electrical  Double Layer and Zeta Potential	
  3 Structure  of Soil Particle	    19
  4 Rearrangement of Particles from Application of Acoustic Field....     20
  5 Schematic  of Laboratory Test  Unit	    36
  6 Test Unit  and Acoustic Instrumentation	    37
  7 Typical Acoustic  Signals Acquired  During Testing	    38
  8 Signals Indicating Nonlinear Interaction Between Drive Piston
       and soi 1 column	    38
  9 Side View of Testing Cell for Electroacoustic Soil
       Decontamination Process Used for Decane Soil  Treatment	   40
 10 Side View of Modified Testing Cell for Electroacoustic  Soil
Decontamination  Process  Used  for  Soil, Zinc/Cadmium
       Soi 1 Treatment	   42
 11 Side View of the Treated  ESD  Cake  in Decane Tests
       (26D,  27D,  28), and 30D)  Showing the Three Analyzed Layers	   46
 12 Top View of Decane Layer Showing how the
       Layer was  Divided and  Analyzed	    46
 13 Side View of Decane-Treated ESD  Cake  Showing Layer
       Moisture Content	   50
 14 Zande Measured Decane Concentration Plotted
       Versus  EPA Measured Concentration	   56
 15 Solubility of ZnO  as  a Function  of pH	   60
 16 Schematic  of the Cake-Divided Sections  for Tests  7Z-16Z         63
 17 Variation of Percent Zinc Removed/Accumulated as a Function of
       Cake Gradient for  25 and  100 Hours'  Leaching Time	  64
                                    vii

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                                     FIGURES
                                    (Continued)

-Number                                                                       Page

  18   Variation of Percent  Zinc  Removed/Accumulated  as a
        Function of Cake Gradient for 0,  0.013,  0.144  and 0.811
        Average  Power  Input  for  50  Hours'   Leaching  Time	       -68

  19  Variation of Zinc Concentration as a Function of Cake Gradient at
        0.013,  0.144  and 0.869 W Power  Input  for 50  Hours' Leaching Time      69

  20  Variation of Zinc Removed  (wt%) as a Function  of Cake Gradient at
        1.432  W  and  0.390  W for 100  Hours' Leaching  Time	       71

  21  Acoustic  Input Power Versus Record Number	      -72

  22  Schematic of Cake Divided Sections for Zinc/Cadmium Test	      -77

  23  Distribution of Hydrolysis  Products (x,  y) at  I  = 1 m and 25' in
        Solutions Saturated with fS-Cd(OH)	      -79
                                       Vlll

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                                     TABLES
Number                                                                       Paqe
   1   Applications  of Electra-Osmosis in  Soil  Leaching, Consolidation,
         and  Dewatering	      -5
   2   Zeta Potential  of Soils	     -13
   3   Particle-Size Distribution  of Samples of the  Soil 	     -29
   4   Soil  Characteristics	     -30
   5   Initial  Percent  Decane Contamination in Soil  Before  BSD,
         Reported  by Zande Lab	     -32
   6   Initial Zinc Concentration  in the Soil Reported by Zande	     33
   7   Initial Zinc and Cadmium Concentration in the Zinc/Cadmium  Soil        -34
   8   Effect of Electric Field on  the Decan Mobility	     48
   9   Statistical  Analysis Results for  Decane  Tests 	     -52
  10   EPA  and Zande Measured  Decane  Concentrations  and  Their
         Differences  in  Soil  (Dry Basis)	     -55
  11   Comparative  Analytical  Determination of Decane  in Soils by  U.S.
         EPA  and Zande Laboratories	      57
  12   QC Data for  EPA Analyses	     -58
  13   Percent Ionic Distribution for ZnCl, at Ph 6  and  9.7	     62
  14   Sample  Mass  Balance  Around  the Zinc for Test  No.  162	     -64
  15    Zinc Concentration  at  Different Cake  Gradient for Different
         Leaching  Time	     -67
  16    Acoustic  Data for Zinc Experiments	     -73
  17    Performance  of  ESD Process  on  Zinc/Cadmium  Soil	     76
  18    Percent Ionic Distribution for ZnCl,  and  CdCl, at pH  7, 8, and  9.      -80
  19    Zinc QA Data	     81
 20    Analytical Data for  Zinc Soil	     -82
 21    Analytical Data  for  Cadmium  in  Soils	     -83
                                        IX

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                                     TABLES
                                  (Continued)

Number                                                                      paqe

  -22 QC  Data  for  Zinc	      85

  23 QC  Data for Cadmium	   	      86

  24 Comparison of  Electra-Acoustical  Soil  Decontamination (BSD)
         to Other In-Situ Technologies	      89

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                         ACKNOWLEDGEMENT
     This report was prepared under  the  direction  and coordination
of  Diana Guzman, U.  S.   EPA SITE  Project Manager in  the Risk
reduction Engineering Laboratory,  Cincinnati, Ohio.  Reviewers for
this report were Denis Nelson,  Chemical Engineer; Jonathan G.
Herrmann,  Civil Engineer:  Herbert  R. Pahren,  Chemical Engineer:  and
David  Smith,   Quality  Assurance   Manager.  All  of  the  above
individuals  are employees  of the EPA's  Risk Reduction Engineering
Laboratory in Cincinnati,  Ohio.

     This report was  prepared  for EPA's Superfund Innovative
TEchnology Evaluation (SITE)  Program by H. S.  Muralidhara,  B. F.
Jirjis, F. B.  Stulen,  G.  B.  Wickramanayake, A.  Gill,  and R. E.
Hinchee  of  Battelle   -  Columbus  for  the  U.  S.  Environmental
Protection Agency under Cooperative Agreement NO.  CR815324-01-0.
                               XII

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                                   SECTION  1
                                   INTRODUCTION

     Many sites  in the U.S. are  contaminated with nonaqueous phase liquids
 (NAPL) and  heavy metals'".   The U.S. Environmental Protection  Agency  (U.S.
EPA) has  estimated that  189,000  underground  storage tanks are  leaking  at
retail fuel outlets alone.   NAPL contamination in  the  form of coal tars and
petroleum sludges  from above-ground  tanks is also  a  significant problem.
Following a NAPL spill or release,   the  liquid  typically migrates to the water
table where it spreads out and floats,  since it is lighter  than water. In a
typical cleanup,  the  initial  phase  recovers the  free  phase "floating"  NAPL.
The fraction  of spill which  is  recoverable  utilizing conventional  technology
 is very  low,  and  residual  contamination  following drainage of this recoverable
NAPL is very high, often  in  the  range of several  percent'2'.
     Moreover,  improper  disposal  of industrial wastes  containing heavy metal s
has created a serious problem  in a  number of locations.  Because of increasing
proliferation  of these wastes,  contamination of  the  ground and  groundwater  at
a number  of locations is causing a  serious  threat  to  the environment.
     The  current state-of-the-art in remediating these  sites  is  to recover all
pumpable separate phase organic liquids  and  then treat  the residuals either
 in-situ via bioreclamation,  soil  venting, soil washing  or flushing, to  pump
and treat,  or  to excavate.   The  initial  recovery of pumpable product depending
upon the site,  is typically limited to  20-25  percent  recovery and  in  many
cases even  less.   Hence,  the U.S. EPA awarded  a Phase  I  Superfund  Innovative
Technologies  Evaluation  program cooperative agreement  to Battelle  Columbus
Laboratories  to  demonstrate the technical feasibility of the ESD concept.
This technology will  potentially increase the  recovery rate and lessen the
need for  follow-on residual clean up or  reduce  the cost where some follow-on
 is required.

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      This report provides the information related to technical  feasibility of
 Battelie's  BSD  technology.   The report is organized as follows.
      Background information related to prior art and theoretical principles on
 electrokinetics and acoustics is provided  in  Section 3.  Project planning,
 including QA/QC  plan,  is given in Section 4.   Experimental  Investigation,
 Results  and  Discussion  are  provided  in Sections  5 and 6,  respectively.
 Technical performance of BSD with other in situ technologies on organic  and
 metal  treatment is provided  in Section 7.  Summary,  Conclusions, and
 Recommendations  are  provided  in  Sections  8 and 9, respectively.
      The project objective was to establish the feasibility of  the  in situ BSD
 for  decontaminating hazardous waste sites. The  goals of the two-phase
 developmental effort were to demonstrate the capability of this BSD process
 to:
          Decontaminate soils  containing  hazardous organics in situ by the
           application  of d.c.  electrical  and acoustic fields
           Decontaminate soils containing heavy metals by the application of
           d.c.  electric  and acoustic  fields.
     The  program was proposed in two  phases:  Phase  I -  Laboratory
 Investigation and Phase  II - Field Demonstration.  Phase I  objectives  were  to
determine the effects of process parameters on BSD performance and to
recommend  parameter ranges and a design  to be evaluated  in Phase II. Phase I
consisted of the  following  tasks:
           Project  Planning
     •    Material  Selection/Characterization
     •    Parametric  Investigations
          Assessment of  In-Situ  Technologies
          Final Report.
This Phase I report  includes  the  background of BSD technology,  mechanisms  of
both the  electric  and  acoustic fields,  details of experimental   setup,  results
on decane,  zinc,  and zinc and cadmium,  and summary conclusions   of the
 investigation.
     A Phase II small scale  field  study on heavy metal decontamination is
needed to obtain further  information related to  specification and
configuration of the electrodes and acoustic driver  in the field.

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                                    SECTION  2
                                   BACKGROUND

     The BSD process is based on applying  d.c.  electric and acoustic  fields to
contaminated soils  to obtain increased transport  of liquids and metal  ions
through the soils.   Figure 1 illustrates the  operating principle of the
process.    Electrodes (one or more anodes and  a  cathode)  and an acoustic source
are placed  in  a contaminated soil to apply the  electric and acoustic  fields  to
the soil.    Increased transport  of liquids  through the soil is obtained by
applying the electric and acoustic fields.   The process is expected to be most
effective for  clay-type soils having small  pores  or capillaries, in which
hydraulic permeability  is very  slight.
          The  dominant  mechanism of the  enhanced  flow is  electroosmosis
resulting from  the  electric field.    In-situ electro-osmosis was first
successfully applied  to soils by L. Casagrande  in the 1930s in Germany for
dewatering  and stabilizing soils'34'.  Recently,  Muralidhara  and  co-workers
at Battelle have  discovered that the simultaneous application  of an electric
field and  an  acoustic field produces a  synergistic effect and results  in
further  enhancement of water transport'514'. This Battelle's process  is
termed electro-acoustic dewatering  (EAD).   Battelle is actively engaged  in  the
development and commercialization of the EAD  process for a variety of
industrial and  wastewater treatment applications.
     Based on  our extensive research and development experience in the
application of  electric and acoustic  fields to  dewatering  and  proven soil
dewatering technology utilizing electroosmosis,  Battelle is utilizing the
principles of  EAD technology to decontaminate  soil in-situ. Background
information on  theories and operating principles  is provided in the following
sections.   Prior  related applications are  summarized  in  Table  1.

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                         Flushing  (Optional)
                                                                        Pumping  Contaminants
                                                                       with Croundnater
                                              Acoustic Source
Ground Surface
                      Anode
              On $• tort ted  lorit
       Water Table
                                                               lAcoustf
                                                               Waves
                  Zone
                                                     Contaminant
                                                       (NAPL)
 Cathode
Steel Recovery Well
(with 2 pumps  system)
                                                                              i. - J
                      Figure 1.  Conceptual  Layout of Electra-acoustic Soil Decontamination
                                  (Final design may vary based upon  laboratory testing).

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               TABLE
                     APPLICATIONS OF  ELECTROOSMOSIS  IN SOIL LEACHING,  CONSOLIDATION,  AND  DEWATERING
     Application
     Leaching of Cr
     from soils
     Leaching of Cr
     from soils
ul
Crude oil
product i on
                      Investigators
                      Banerjee^   '
Scale of
Operation
Voltage and  Current
                      Horng et al.
                                       (23)
Laboratory
Laboratory and
field
  0.1 to 1.0 V/cm
        N/A
                           Anbah et al.
                                         (24)
Laboratory
        N/A
Results and  Comments
 Obtained  increased
 leaching rate with
 electric field

 Obtained  increased
 leaching rate with
 electric field;
 determined  effect
 of anode materials

 Obtained  increased
 flow of oil -water
 mixture  through
 porous  media; de-
 termined beneficial
 effect  of a small
 addition of elec-
 trolyte  to  kerosene
 to obtain  increased
 electroosmotic  flow
     Soil  consolidation    Hardy
                                               Laboratory and
                                               field
                          N/A
                            Treated  highly
                            plastic  clays with
                            liquid  limits
                            ranging  from 45  to
                            107  and plasticity
                            indices  ranging
                            from 27  to 28 and
                            achieved 300 per-
                            cent increase in
                            the strength of  the
                            clay

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                                             TABLE 1.   (CONTINUED)
Application
Investigators
Scale of
Operation
Voltage and Current
Leaching of salts     Probstein et al.  (27)    Laboratory
and organic acid
                                              1-1.5 V/cm
Soil  consolidation  Mitchell  et   al.
                                        (28)
                          Laboratory
                         and  theoretical
                          development
                        0.75 V/cm
Results and  Comments
                            Looked at model
                            systems such  as
                            Kaolin clay  satur-
                            ated with  organic
                            acid cacetic acid.
                            Results suggest
                            that current
                            efficiency
                            increases  with
                            increase in
                            concentration  which
                            is  contrary  to
                            predictions.

                            An  excellent paper
                            on  theoretical
                            aspects  of electro-
                            osmosis applied  to
                            soil  consolidation
                            systems

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                                             TABLE 1.    (CONTINUED)
Application
Investigators
 Scale of
 Operation
Voltage and Current
Enhanced oil
recovery
Fleureau et  al.
                                     (30)
Laboratory
        N/A
Electroreclamat i on
in soils
Lageman
(Geokinetics N.L.)
   Field
   Field Study
 Results and  Comments
• Experiments de-
  termined the
  influence of
  electrochemical
  phenomena on
  interfacial tension
  and wettability
  parameters.  They
  observed in-situ
  formation of the
  surfactants which
  was responsible for
  reducing  inter-
  facial  tension

• Decontamination of
  heavy metals
  especially AS.Cd,
  CO, Cr, Cu, Ag, Ni,
  Mn, Mo.   About 90
  percent removal
  claimed.  Remed-
  iation  costs
  ranging from $50
  per ton to $400 per
  ton.

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                                                  TABLE 1.    (CONTINUED)
    Application
Investigators
 Scale of
 Operation
Voltage and Current
 Results and  Comments
     Soil  dewatering
     (Salzgitter,
     Germany)
Casagrande^2'3)
Field
180 V 9.5  A/Well
00
                                     (2
     Soil  dewatering       Casagrandev '
     (Trondheim, Norway)
                          Field
                    40 V 26 A/well
     Dewatering of
     waste suspensions
Kelsh
                                (29)
Lab and  Field
         N/A
. Electrodes placed
  22.5 ft deep  and
  15 ft  apart;  flow
  rate increased  by  a
  factor of 150 from
  10 gal/day well
  without electric
  field  to  1500
  gal/day/we11  with
  electric  field;
  energy usage  was
  0.38 kwh/gal.

• Electrodes placed
  60 ft  deep  and  15
  ft apart;  flow  rate
  increased  from  6
  300 gal/day/we11  to
  70-3040 gal/day/
  well;  energy  usage
  was 0.30  kwh/gal.

. Applications  of
  electrokinetics  to
  number of waste
  streams such  as
  slimes, ultrafine
  coal waste, mine
  tailings  pulp,  and
  paper  mill  sludges.

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                                             TABLE  1.   (CONTINUED)
Application
Investigators
 Scale of
 Operation
Voltage and  Current
Electroreclamat i on
of  contamianted
soils
Hammett
                             (26)
Lab
         N/A
Desalting  from
soils
                        Lab and Field
                         50 V/in.
Electroosmotic
dewatering
Lockhart
                               (31)
Lab and Field
         N/A
Results and  Comments
 Very  informative
 background work  and
 good discussion  on
 electrokinetic
 aspects of  trans-
 port of contam-
 inants in the  soil.

 An  interesting
 approach to  trans -
 port salt from
 soil.    It  is poss-
 ible to  selectively
 transport (P04),
 (N03) to the root
 zone.

 Applications  of
 electrokinetics to
 dewatering  of
 minerals,  coal and
 a very good  inter-
 pretation of
 mechanisms  of
 electroosmosis
 dur i ng dewater i ng.

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ELECTRO-KINETIC PHENOMENA PRINCIPLES

      The  application of a d.c. electric field to  a  soil  high in clay content
 results  in the following phenomena:
           Electra-osmosis
      •     Electra-phoresis
           Current flow
           Ion migration
      •     Joule's heating
           Ion diffusion.

 Each  of these has implications for the  design  and operation of BSD processing
 schemes,  which are discussed in the following sections.

 Electro-osmosis

      Electro-osmosis^ '   ' in porous media,  such as clays,  is  due to an
 electrical double layer  of negative and positive ions formed at  the  solid-
 liquid  interface.   For soil particles,  the  double layer  consists of a fixed
 layer of  negative ions  that are firmly  held  to  the  solid phase and a diffuse
 layer of  positive ions that are more  loosely held.  Application of an electric
 potential on  the double  layer results in the displacement of the two layers to
 respective  electrodes;  i.e.,  the positively  charged  layer to the cathode and
 the negatively charged  layer  to the anode.
      Since the particles in the soils are immobile,  the  fixed layer of the
 negative  ions  is  unable to move.    However,  the  diffuse layer containing
 positive  ions can move and drag water along with it to the  cathode.  This  is
 the basic mechanism  of electro-osmotic  transport  of  water through wet soils
 under the influence of an applied  electric  potential. Figure  2  shows the
 electrical double  layer and zeta potential.
      The  rate of flow by electroosmosis through a single capillary is given by
 ju,          .   (3,15)
 the expression
                EDr2Z
           Q   = 4nL
                                        10

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                      Solid Phase



      //// / I /1  11  I  I  I  I  I  I

                                                         Fixed Layer

  Zeta       +   +    -    +   +    +    -   +    +    +
Potential                                                  Diffuse  Layer
              +   -   +    +   -    +    +   +    -+    (Mobile)
    Figure 2.  Electrical  Double Layer and Zeta Potential^  '
                               11

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                                             o
where      Q = electro-osmotic  flow rate, cm /sec
           E = applied electric potential, volts
           L = length of capillary  between  electrodes,  cm
           D = dielectric constant of the  liquid      „
           g = viscosity of the  liquid,  dynes-sec/cm
           Z = zeta potential, volts x  10
           r = radius of capillary, cm
The above  expression is  valid for  soils  where pore diameters are  large
compared with the  thickness of the double layer.   The electro-osmotic  flow
velocity  (U cm/sec)  is obtained by dividing the flow rate,  Q, by  the  cross-
                                    0
sectional  area of the capillary  (pr ) as  follows:
               EDZ
           U = 4pgL
The above  expression indicates that the  electro-osmotic  flow velocity is
independent  of the capillary diameter,  a  key advantage of  electro-osmosis  over
conventional  flow  under  a pressure gradient.   In the absence of an electric
field, the flow  of water through small pores  essentially  stops.
     An  important  parameter of electro-osmotic flow is the  zeta potential,  Z,
which  is the potential  drop across the diffuse  part of the  electric double
layer  that controls electro-osmosis.    It  represents the  electro-kinetic  charge
which  exists  at  the sol id-liquid interface  of particles  in suspension.
Typical  values of zeta potential reported by Hunter^5' for  various types of
soils  are  given  in Table  2.   The data  indicate  that electro-osmosis is more
efficient  in  clay-type soils  than in  sandy soils.
     Some  noteworthy examples of the  prior  work on soil  leaching,
consolidation, and  dewatering by  electro-osmosis are summarized  in Table 1.
Numerous patents have been issued  in various  applications of electric field
for enhanced recovery of crude  oir    ' The examples demonstrate the
feasibility  and  practicality  of  electro-osmosis in large-scale applications.
The reported  electrical  energy  consumption  in the  range of  0.3 to 0.4 kwh/gal
is  low and should be acceptable  for  soil decontamination applications
($0.015/gal  to $0.020/gal power cost).   The  examples  of  metal leaching,  oil
recovery,  and Casagrande's work  in particular on  soil  dewatering  clearly
indicate that the  application of the electric field has  been successful enough
to suggest that  Battelle's BSD technology would perform  adequately at pilot-
scale  levels  and,  eventually, full-scale levels.

                                        12

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                       TABLE 2.   ZETA POTENTIAL OF SOILS*
Type of Soil                                              Zeta Potential  (mV)






Lithium  vermiculite                                              -80




Sodium bentonite                                                 -40




Silica sand                                                      -10




Quartz sand                                                      - 25




Kaolin clay                                                      -80






*  Ref.  15
                                      13

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 Current  Flow

      When a voltage is applied  across  an electrolyte solution,  there is a
 current  flow that  is  proportional  to the electrical conductivity  (or  inversely
 proportional to the resistance) of the solution. This  is the familiar Ohm's
 law:
           I = E/R                                                       (1)
where I (amps) is the  current, E (volts) the  applied voltage, and R (ohms)  the
 electrical  resistance.  The  resistance decreases as  ionic  strength  increases
 and as the temperature increases.
      During the ESD process,  it is desirable to minimize the current  flow for
 a given zeta potential to  reduce power consumption and to  minimize  the Joule
 heating;  a discussion of current flow phenomenological  effects  follows.

 Ion Migration

      When a direct current  is passed through an electrolytic solution, the
 cathode  acts as a source of  electrons  and the anode acts  as an electron sink.
 Positive ions will travel  toward the negative electrode  (cathode),  whereas
 negative ions will travel  toward the  positive electrode (anode). The  positive
 ions have a tendency  to  accept electrons at  cathode surface  and negative ions
 electrons at the anode surface.  The overall transport of  ions  in the bulk
 medium is defined as  ionic migration.
      Flux of ionic species  in the  presence  of a d.c. electric field  is given
by:
                                                p
      Ji  = viCiE,  flux of  i  species  moles/sec  cm
      v.  = ionic mobility of  i  species cmVsec/volt
      C=  = concentration of  i  species,  moles/cm3
      E = electric  field, E/cm
      The ionic mobility is the  speed at which the  ion moves  toward  the
 respective electrode  in  the applied electric field.  This speed  is  determined
 by the viscosity of solvent,  the conductivity of solvent, the strength of the
 applied  field,  and the size  and the  shape of the ion.
                                        14

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 Ion Diffusion

      Ionic diffusion is another  phenomenon  that occurs in an  electrolysis
medium in the presence of a  d.c.  electric field. The  concentration of ions
near the electrode is always higher  than the bulk concentration.   This
enrichment  of ions near electrode surface promotes  flow of ions from a  higher
to  lower concentration.
      Ionic flux results from diffusion is given by:
      J,  =  D| YC.
      Jj =  flux of  i  species  moles/sec cm
      D = diffusion coefficient cm  /sec      „
      Cj = concentration of i species moles/cm15
Ion  transport resulting  from  convection  is rather minimal  in in-situ treat-
ment,  due  to  the nature of flow in the soil  medium.

Joule's  Heating

      When  a current passes through  a solution,  the  electrical energy is
converted  to  heat according to the  equation
           q =  El
where q (cals/sec)  is the heating rate,  E (volts)  is  the  applied  voltage,  and
 I (amps) the electric  current  through the solution.  This  heating of the
solution is called Joule's heat.  The temperature increase of the soil  may be
approximated  as
                          £L
           tout - tin  =   FCP
where F  (gm/sec)  is the  soil  flow rate and Cp  (Cal/mole,°C)  is the soil heat
capacity.   In addition to the Joule's heat,  part of the power input is
consumed by electrolysis of water.   This electrolysis power loss  should be
subtracted  from the total  power to  obtain a better  estimate of  the temperature
increase.
                                        15

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 Electrolysis

      The voltage  used  in BSD greatly exceeds the potential required  for
 electrolysis of water.   Therefore, during BSD,  electrolysis occurs. Hydrogen
 is  liberated at the cathode and oxygen at the anode.  The evolution of these
 gases would induce  a pH  change at  electrodes resulting from the presence of H+
 and OH- ions.   OH-  combines  with Na+  and  similar ions present in the cake at
 the cathode and passes through  the filtrate  or precipitate at the electrode.
 This reaction  causes the pH of the filtrate  to  become basic. For the opposite
 reasons, the cake at the anode  becomes  acidic.
      Generally the  movement  of  the liquid or the particle occurs during
 electroosmosis  or  electrophoresis.   However,  during electrolysis, the  movement
 of  ions or complexing of ions occurs.   It has been  observed  that generally  the
 ions'  mobility is an order of magnitude  larger  than electro-osmotic  velocity
 and hence the total  energy required to  move  the  ion through the soil column
 should be much less than electro-osmotic  velocity.
                           (25)
      According  to Lageman     of  Geokinetics, the following factors play a key
 role in determining the  efficiency of the electrolysis process during heavy
 metal  decontamination of the soil. The factors  are:
           Nature  of contaminant
           Concentration  of heavy metals
           Soil  type
           Ionic radius
           Solubility of  contaminant as  a  function of pH
           Ease  of release of  contaminant  from the  soil
      •     pH control around the electrodes.

ACOUSTIC PHENOMENA PRINCIPLES

     An acoustic  field is one in which the acoustic pressure and particle
 velocity vary as  a function of time and position.   These pressure fluctuations
 form a traveling wave,  which propagates from  the source throughout  the  medium.
 Sinusoidal  pressure fluctuations are characterized by their pressure amplitude
 and  frequency.  A particle velocity is  imparted  to the medium by the action of
 the  pressure wave  which also varies as a  function of time,  frequency, and
                                        16

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 position.   Acoustic pressure and particle velocities  are related through the
 acoustic  impedance  of the medium.
      The  pressure fluctuations are the result of the  transmission of
 mechanical  energy that can perform useful work to bring  about  desired effects
 The type  and magnitude of these effects  depend on the medium.  In acoustic
 leaching, many of the forces that can contribute to  the  overall effectiveness
 include:
      •    Ortho-kinetic forces, which  cause  small particles to agglomerate
          BernouHi's force, which  causes larger particles to  agglomerate
          Rectified Diffusion,  which causes  gas bubbles  to grow inside
          capillaries  and thereby  expel  entrapped liquids
           "Rectified"  Stokes'  force,  which causes an  apparent  viscosity  to
          vary nonlinearly  and forces the particle toward the  source
          Decreased Apparent Viscosity which may be  due to high  strain  rates
           in a thixotropic medium or  localized heating which  in turn lowers
          both the viscosity and the driving force to move particles
          Radiation Pressure is a static pressure which  is a second-order
          effect  adding  to  the normal pressure differential.
      A  precise understanding of the relative significance of each of the
 listed  mechanisms or a given system/medium  is  unavailable.  The contributions
 to  effective  acoustic  leaching  are  also  dependent  on  the type  of  material
 being treated  since all  the  mechanisms listed depend  on  the  physical/chemical
 properties  of the material under treatment. Therefore,  it is difficult  to
 predict performance  a  priori,  and experimental  testing is needed  to establish
 baseline  performance.  A more thorough review is available in  the two articles
 by  Ensminger and Muralidhara^  '
      To introduce high-energy acoustic signals into the ground, one must
 address the issues of elastic wave propagation  in solids. The earth,  for  the
 purposes  of in-situ leaching,  can  be treated as a semi-infinite half space,  in
which the earth's surface is  the boundary of the half-space.    It is well known
 that  a  source  acting normal  to and on the surface not only produces acoustic
waves (more properly referred  to as  compression waves in this case)  but  two
 additional waves as  well.   These  are shear waves, where  particle  velocity  is
 perpendicular  to  the direction of propagation,  and  surface waves.  Surface
waves exist at  the  boundary,  extend a given  depth into the medium,  which is
                                       17

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 inversely proportional to  the  wavelength,  and  produce  elliptical  particle
 motions.
      Thus, the energy  into the source is partitioned into these three  types  of
 waves with roughly 10  percent  going  into compression,  25 percent  into  shear,
 and 65 percent into  surface  waves.   Likewise, as the  signal  propagates from
 the source, the  intensity  of the compression and shear waves  decrease  as  the
 inverse of distance  squared  because  they are propagating in the bulk of the
 material.   Since the  surface waves  propagate beneath the surface  of  the
 material, their  intensity  decreases  as the inverse of the square  root  of
 distance.   In addition,  all  three waves  will be further reduced by soil
 attenuation, which generally increases by the square  of frequency. Therefore,
 lower frequency  waves will propagate  (i.e.,  penetrate) much  further.  Buried
 sources would produce  mainly shear  and compression waves.  The  relative
 amounts depend on the  design of the  source.
      Battelie's  experimental work thus  far  has focused on acoustic
 (compression)  waves.    Therefore,  it  is difficult to state how effective the
 different  wave types  would be  in  leaching, but  they may still  be  effective.
 Note that the beneficial effects of  decreased apparent viscosity  may be
 greatly improved  with  shear  waves.
      Another  potential appliication of  acoustics  is  for clearing the  skin  in
 the recovery  well.   As more  contaminant  particles  are  driven  to the  recovery
 well,  the pores and  interstitial spaces can become plugged.  Beard and
 Stulen^  '  have demonstrated  that when acoustic energy is applied to plugged
 glass  frits or limestone specimens,  five-  to ten-fold  increases in flow are
 observed.   This application  of acoustics is  mentioned here to demonstrate our
 experience  with  producing  wells.  This effect is not part of  the  BSD
 technology  and is beyond the scope of  this proposed work on  BSD.

COMBINED ELECTRO-ACOUSTIC SEPARATION  PRINCIPLES

      Acoustics, when properly  applied  in conjunction with electro-separation
 and water flow would enhance dewatering or  leaching.  The phenomena that
 augment  dewatering  when using  the combined technique  are not  fully understood.
                                        18

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However, we  have developed some hypotheses  about  possible  mechanisms which can
be  supported  by experimental  results.
      It is theorized that, in the presence  of a continuous liquid phase, the
acoustic phenomena  (e.g.,  inertial and  cavitation forces)  that separate the
liquid  from  the solid into the continuum  are  facilitated by the electric field
and a pressure differential to enhance  dewatering by means of one or more of
the  electro-separation  phenomena.   There  is also  evidence  of synergistic
effects of the combined approach. For example, free radical  formation
phenomenon should aid electro-separation.  In add it ion, as the  cake is
densified  (by  sequestration  and electro-osmosis),   the  liquid  continuum would
be normally  lost,  but it is believed that,  by chanelling on  a  macroscale,
acoustic energy  delays the  loss of the continuum,   making additional dewatering
possible.   It  is the carefully executed combination  of techniques  to mutually
augment the overall  solid/liquid separation process  that is the essence of
Battelle's current BAD process.   And  because  of this combined effect,  BAD has
been found to  be more effective than either electro-separation  or acoustically
enhanced separation  alone.   The same  effectiveness is  expected  for  BSD.
     Soil  particles  are  generally  colloidal  in nature  and the structure  of the
soil particle may be  indicated, as shown in Figure 3.
          A.
          B.
          C.
          D.
          E.
Continuous capillary  or  pore
Closed capillary  or  pore
Chemisorbed  surface
Contaminate  between  the  two particles in a medium
Water  molecules
                    Figure 3.  Structure of  Soil  Particle
                                       19

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     Application of electric field will tend to mobilize the liquid present in
an open capillary such as A by electro-osmosis.  Acoustic field has the
ability to pump out the liquid present in closed pores such as B by a
mechanism called rectified diffusion (discussed earlier in Section 3.2).
Application of acoustic field could also rearrange the particles, creating new
channels to assist electro-osmosis, as shown in Figure 4.
     Before applying acoustics
   (open-ended capillary closed)
  After applying acoustics
(open-ended capillaries open)
   Figure  4.   Rearrangement  of Particles  from  Application  of  Acoustic  Field.

Rearrangement of particles by acoustic field opens up new capillaries, and
hence, electro-osmosis becomes more effective.  It was postulated that
application of electro-acoustics in the presence of hydraulic gradient would
basically
          Enhance co-transport of decane  with  movement of water because of  ts
          hydrophobic and light nature
          Transport heavy metals by mere  ion migration and electro-osmosis
                                      20

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                                    SECTION 3
                                PROJECT  PLANNING

     This project was  conducted under the U.S. EPA's  Emerging Technologies
Program, which  is  a part of  the  Superfund Innovative Technology Evaluation
Program.   The project  sponsored by the Risk Reduction Engineering Laboratory
under the above  programs required a detail test  plan  that includes a quality
assurance project plan,  material  selection and  characterization,  and
experimental design.   These items were discussed with the project officer as
part of the project  planning,  and the written  document experimental design was
submitted to U.S. EPA  prior to initiation of the study.

QUALITY ASSURANCE  PROJECT PLAN

     The initial requirement of this program was to develop a Quality
Assurance Project Plan (QAPP) that included the  following items:
      1.  Project  description and intended use of  the data
      2.  Project  organization and  responsibilities
      3.  Personnel  qualification
      4.  Procedures used to assess data  quality
      5.  Quality  assurance  objectives  for  critical measurements
      6.  Experimental  procedures
      7.  Critical  test parameters and  analytical  procedures
      8.  Data  collection,  analysis, and  reporting
      9.   Internal  quality control checks
     10.  Performance  and system audits
     11.  Project  staffing and percent  time  on project
     12.  Schedule
     13.  Work  plan
     14.  Analytical methods and operating  procedures for  instruments.
                                        21

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     The QAPP was approved by the U.S. EPA before  initiating the experimental
 studies.

MATERIAL SELECTION  AND CHARACTERIZATION

Soil  Types

      Different  types of soils  contaminated  with organics and inorganics at
 superfund  sites can range  from  highly permeable sandy soils to  less-  permeable
 clays.   The extent of chemical  adsorption to  clay is relatively high  and
 mobilization  of these compounds from  such soils is known to be  difficult.
 Therefore,  we proposed to  focus most  of our efforts on contaminated clay  soils
 to test the applicability  of the  electric  and acoustic fields for
 decontamination.
      The soils for the present  study  were  either clay loam, sandy clay, silty
 clay, or clay having  over 40 percent clay  content.  Appropriate sources of
 clay soil  were  located in Northern Ohio with the help  of the U.S.  Soil
 Conservation  Service.   The soils  were classified for their  constituents and
 characterized  by particle-size  analyses.   Soil  was also  analyzed for  organic
 matter  content.   All of these  analyses  were performed  by the Ohio Soil
 Characterization  Laboratory,  Department of  Agronomy,  The Ohio State
 University,  Columbus,  Ohio.  The  standard  operating procedure for all  the
 analyses is briefly presented in Section 5.

 Organic  and Inorganic  Contaminants

      The potential applicability  for  BSD is expected to  range from  insoluble
 organics (e.g.,  petroleum  hydrocarbons  and  halogenated organic  solvents)  to
 inorganics,  such as heavy  metals  (Cr,  Cd,  Pb)  and cyanide.    For the screening
 level studies,  we proposed to  use a relatively nonvolatile  heavy hydrocarbon
 (decane) and one heavy metal (zinc) as soil contaminants.   Decane was  selected
 as the nonaqueous phase liquid because it  is a constituent  of petroleum
 products and is used  in a number of  industries  including organic synthesis,
 jet fuel research,  rubber, and paper.  It  is  also used  as  a solvent.   Zinc was
                                        22

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selected for our inorganic species  because it is one of the  heavy metals that
 is frequently a soil contaminant.   Selection  of zinc  was  also based on  its  low
 toxicity and relative  ease  involved in handling,  analysis,  and disposal.  If
 the heavy metal removal was  found  to  be effective with zinc, additional tests
 with  another metal (e.g.,  cadmium)  would  be  conducted.

 Electrical  and Acoustical Properties

      Prior to the work  in the  test unit,  ranges of the basic electrical and
 acoustical  properties for a  given  sample  preparation  were determined.    These
 parameters include pH,  electrical conductivity,  acoustical  impedance,
 attenuation,  and zeta potentials.   These  values are expected to be useful in
 estimating initial parameters  for use in the test  cell.  That is, the
 intensity of the acoustic source,  the  placement of the electrodes relative to
 the acoustic driver,  the voltage,  and  the electrode spacing.

 EXPERIMENTAL INVESTIGATION

Preparation of Soils

      The clay soil obtained  for  the present study was mixed with decane to
 yield a concentration of 8 weight percent  (dry  basis)  or  with zinc chloride
 (ZnCl2)  to yield 1 g  of Zn per kilogram of soil (0.2 percent dry  basis).  For
 additional  tests  with metals, it was planned  that  cadmium salts  would  be mixed
 with  zinc to yield 1 g/kg of Cd  and 1  g/kg of Zn. The soil  samples with the
 respective contaminants were thoroughly mixed and four samples from different
 locations were obtained to  determine  the uniformity of  composition.  Decane
 analysis was performed by a gas  chromatographic method, whereas the zinc
 content  was determined by atomic  absorption  spectroscopy  (Section 5).

Bench-Scale  Study with  a Test Unit

      A test unit was constructed as a  simple modular design of stacked
 sections to control  the size of  the test  specimen.   The  internal  dimensions of
                                        23

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the test  cell  were chosen so as to  generate  acoustic  plane waves into the soil
sample.   A  detailed description of this unit  is given  in Section 5.2.
      Ifthe  acoustic field is to treat the bulk of the  soil in the ultimate
application,  it is necessary to minimize  attenuation.   In  most  homogeneous
materials the  attenuation  increases  as the square of  frequency.   Published
data  on clays  indicate that attenuation at 400 Hz is  on the order of 1 to 2  dB
per foot, at 1000 Hz is 8 to 9 dB per foot and at 4000 Hz is 20 to 33 dB per
foot'37'. Therefore, it is  clear that to obtain reasonable  penetration,  the
frequency must  be  kept  under 500 Hz.
      At 500 Hz, the wavelength in soil  ranges from 3 to 6  in.  The  internal
dimension of the  test unit must be  less than  half the wavelength to propagate
plane waves.   Therefore,  if the test  unit  is  round,  the inside  diameter should
be 3  in.  Longer  wavelengths (i.e.,   lower  frequencies)  can then be
accommodated by the same  test unit.   The  advantage  of launching plane waves  is
that  the  acoustic  field  will be uniform.  That is,  every treatment  volume will
experience  the  same pressure fluctuations and particle  displacements.
      The  electrodes to  generate the electric  field were placed in the test
cell  at a given distance from the acoustic source.  These were fabricated as  a
sandwich  with  insulating  standoffs used to set the  interelectrode separation.
The electrodes  themselves  were  fairly thin mesh screens to allow the acoustic
energy and  liquid  to  pass.
      The  membranes are thin sheets  of rubber on polymer.  The purpose of the
top sheet was  to  enable the acoustic waves to pass  through the sample without
carrying  any product  from  the upper chamber.    The purpose of the bottom sheet
was to collect  the recovered product and enable the acoustic wave to pass on
through to  the  bottom chamber.
      The  test  matrix was designed to evaluate combinations of key parameters
to determine recovery rate as a function  of  the electric and acoustic fields.
The test  variables and  their ranges are as follows:

Applied Voltage or Electrical  Power--
     The  test  was conducted for 3 different  voltages or electrical  power.  One
voltage was  used  for  duplicate  runs.   The control experiment  was conducted at
0 v.
                                       24

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 Acoust i c  Energy- -
      The acoustical  effects were investigated  for 2 frequencies.  It  was
 proposed  to use one  frequency  ranging  from 200-500 Hz and  the  other 1000-2000
 Hz.   A control experiment was  conducted without any acoustical  energy.

 Mo isture  Content - -
      During the application  of electric field,  water in  the  soil  will move
 from the anode toward the cathode.   This will  cause the  anode  layer to become
 dryer.   Since water  is  the  only transport medium  for the contaminant,  water
 was  introduced at the surface  of  the  anode to maintain the moisture content  of
 the soil and  ensure  the transport of  contaminant. The initial  solids percent
 for the decane contaminated  soil  was  about 53  percent while  the initial solids
 percent  for the zinc contaminated soil  was about 62 percent.

 Treatment  Durat i on - -
      The test was  conducted for 3 or  more durations.  The  leachate  volume
 collected at  the  effluent port was noted  with time.
      At  the conclusion of each experiment,  the  soil samples  and,  if relevant,
 leachate were  analyzed for the respective contaminant. All of the analytical
 work  was  performed in Zande  Environmental Services, Columbus, Ohio.   Some
 samples  were analyzed by U.S.  EPA for quality  assurance/quality control
 purposes.   The decane and zinc analytical  methods  are  listed  in Section 5.

ESD Tests on Decane--
      The  critical  test parameters evaluated  in  this project  are the following:
      •    Voltage  (4  levels)
      •    Acoustic power (3  levels)
          Acoustic frequency (1  level)
          Volta e and acoustic
      •    Time 43 levels).
 The experimental  protocol is described below:
      Step   .   Conducted  experiments  at 4 voltage  levels. (0 V/in.,  12.5
      V/in.,  25 V/in., 37.5 V/in.) (4  levels).   These voltage levels were
      chosen based  on  the conductivity  of  the suspension.    Higher  conductivity
                                        25

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      results in  larger voltage,  thereby causing  excessive  electrolysis  and
      internal heating of the suspensions.

      Step 2. A second series of experiments was conducted with acoutstic power
      input as a variable at  1 frequency, no electric was  used .  (0  w,   0.47  w,
      and  W at 400Hz)   (3levels).

      Step 3. Based on the results of Step 1, the best voltage conditions were
      chosen and, based on Step 2,  the best acoustic power setting was chosen,
      and experiments were  conducted at one particular frequency  (3 tests).

      Step  4.  Based on results of Step  1,  a series  of experiments  was
      conducted  with time  as  a variable.   Some of these  tests were  electric
      only and some were  electric and  acoustic.

ESD Tests  on Zinc--
      The critical  test parameters evaluated  in this  project  are  the  following:
           Electric power   (3  levels)
           Acoustic power   (3  levels)
           Acoustic frequency   (2  levels)
           Time  (3 levels).
The experimental  protocol is  described below:
      Step  1.   Conducted experiments at 3 power levels  (0 W,  0.114 W, and  0.811
      W)  for 50  hours and  no  acoustic  power.

      Step  2.   Based on the results of Step 1, the best  electrical power
      condition was chosen and experiments  were conducted at three acoustic
      power levels (0.44 W, 0.88 W and 1.302 W) and one particular frequency
      (400  Hz).

      Step 3.  Based on the results from  Step 2,  the best acoustic power
      condition was chosen, and an experiment  was conducted at the second
      frequency (850  Hz) .
                                       26

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Step  4.   Based  on the results  from Steps 1,2,  and  3,  experiments  were
conducted  for  3 times (25 hours,  50 hours and  100  hours).
                                   27

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                                    SECTION 4
                           EXPERIMENTAL  INVESTIGATION

      In this section of the report,  details of material selection,
 characterization,  experimental  setup, experimental  procedure,  and analytical
 procedures are discussed.   Details are  provided  below.

MATERIAL SELECTION AND  CHARACTERIZATION

      Ten 5-galIon containers of 60 percent clay soil were obtained from
 Paulding, Ohio, with the assistance of the Soil  Conservation Service.  Table 3
 presents the particle-size distribution of the as-received  soil;  The sand,
 silt, and clay contents were 10.8   11.7, 27.2   29.0 and 61.05   59.3
 percent,  respectively.    Based on  the US Department  of Agriculture textural
 classification, the soil used in  the present  study falls into the category of
 clay.   The pH  and  organic carbon contents of the soil are given  in Table 4.
 The soils are acidic and have a pH  of  about 5.5. The organic carbon content
 for this clay soil is  1.87  weight percent  (dry basis).

Soil Preparation

      From each of the  ten  received  containers,  21 Ibs of wet soil (70 percent
 solid)  were  dried  and mixed together.   The  dried  soil  was grounded using an
 Abbe Fitz mill with an opening  of i  in.  screen.  The ground  soil  was used for
 decane  and zinc soil preparation.

Decane Soil  Preparation--
      Sample  of soil prepared by adding  8  weight  percent  (dry basis)  decane in
 the laboratory.   It was  found through  our laboratory testing that the received
 soil did not mix  well  with the decane.   The soil  appeared to have higher
 affinity for decane than water.    Hence, decane was  mixed  with the dry soil

                                        28

-------
TABLE 3.   PARTICLE-SIZE DISTRIBUTION OF  SAMPLES OF THE SOIL
          Particle-Size Distribution
<2 mm




Sand ( mm )
CS MS
2-1 1-0.5 0.5-0.25
0
0
0
0







.7 1.
.8 1
.8 2
.6 1
vcs
cs =
MS
FS =
VFS
TS
CSI
8 3.0
.9 2.8
.0 3.0
.8 2.8
= Very coarse
= Coarse sand
= Medium sand
= Fine sand
Silt (
FS
0.25-0.1
4.2
4.0
4.1
3.8
sand



= Very find sand
= Total sand
= Coarse silt


VFS
0.1-0.
1.6
1.8
1.7
1.9
MSI
FSI
TSI
cc
FC
TC

TS CSI
05 2-0.05 50-20
11.2 10.1
11.1 11.7
11.7 4.6
10.8 12.1
= Medium silt
= Fine silt
= Total silt
= Coarse clay
= Fine clay
= Total clay

MSI
20-5
5.6
4.7
9.1
4.2







urn
) Clay ( urn )
FSI
5-
11.
11.
15.
11.







2
8
2
3
0







TSI
50-2
27.5
27.5
29.0
27.2







CC FC TC
2-0.2 <0.2 <2
39.9 21.6 61.4
39.7 21.8 61.5
40.2 19.1 59.3
39.8 22.4 62.1







Text.
Class
Clay
Clay
Clay
Clay







                            29

-------
     TABLE 4.   SOIL CHAEACTERISTICS (Four Samples)
                                                     Organic
                       _  _
Sample                 Water       0.01 M         Carbon (Wt.  %)
                       (1:1)       (1:2)            Dry Basis
   l                     5.4         5.1               1.89

  2                     5.5          5.2               1.88

  3                     5.5          5.2               1.86

  4                     5.5          5.2               1.86
                          30

-------
 first and then with water to  provide a homogeneous soil decane mix.  The dried
 ground  soil  (15  Ib.)  was mixed with 1.2 Ib. decane using a  Sigma mixer  for 1
 hour.   Further,  the decane-soil mix was mixed with  12.27  Ib.  of water for
 another hour.   iF-rveSjactnea •*«;"•« prepareu ffcVroWffiy^fc same pr-ocedure.   The
 five  prepared  batches were  mixed and placed in  a  sealed  aluminum pan and
 stored  in  a  cooler.   Five samples were  taken  from the mixed decane soil and
 sent  to Zande  Labs for analysis.  The  results are shown in Table 5.  Although
 it  was  intended to prepare 8  percent  (weight, dry basis)  decane, lab analysis
 indicated  an average of 5.14 weight percent (dry  basis) was present in the
 soil.   Further discussion on  initial decane concentration  is provided in
 results section.

Zinc Soil  Preparation--
      The soil  sample was inorganically  contaminated  in the  laboratory by
 adding 0.2 percent  of Zn (D.B.) into  the soil  in the form of ZnCl2  The dried
 ground  soil  (15.44 Ib.) was mixed  in a Sigma  mixer for 1 hour with 11.6  Ib.  of
 0.55 percent ZnCl2  solution  to provide  a  soil containing 0.2  percent Zn. The
 prepared soil  was transferred  to an aluminum  container and  stored in  a cooler.
 Five soil-zinc samples were  taken from  the mixed  zinc soil  and sent to Zande
 Laboratory for analysis.   The  results  are shown in Table  6.

 Zinc-CaafflTunT ioTi Preparat i on
     A  soil  sample (4 Kg) was  inorganically contaminated in the laboratory by
 adding  0.096 percent Zn  (D.B.)  and 0.1 percent Cd (D.B.) into the soil.  Dry
 soil  (15 Ib.)  was first mixed   in a Sigma  mixer  for  1  hour with 9.0 Ib.  of
 ZnCl2  solution to provide a  soil containing 0.096 percent  Zn. The  moisture
 content of the zinc-prepared  soil  was 37.5 percent.  Then,  8.82 Ib. from  the
 above zinc-prepared soil was mixed with 0.86  Ib.  of  1.05 percent CdCl2
 solution to  provide a soil  containing 0.096 percent Zn, 0.1  percent Cd,  and  57
 percent solids.   The prepared  soil  was  mixed  thoroughly and stored in a glass
 beaker  in  a  cooler.   Two soil   zinc/cadmium samples were taken from the above
 prepared soil  and sent to Zande and U.S.  EPA  for  zinc and  cadmium analysis.
 The  results  are  shown in Table 7.
                                       31

-------
TABLE 5.   INITIAL PERCENT DECANE  CONTAMINATION IN SOIL
          BEFORE  BSD,  REPORTED BY ZANDE LAB
First Decane Analysis
Sample
Dl
D2
D3
D4
D5
Sample
Solids (%)
53.12
53.48
53.00
53.18
53.01
Wet Basis
(%)
3.85
3.87
3.36
3.86
3.76
Dry Basis
(%)
7.25
7.25
6.35
7.25
7.10
Corrected Decane Analysis
Wet Basis
2.81
2.83
2.46
2.81
2.75
Dry Basis
5.30
5.29
4.64
5.29
5.18
  53.16
3.74
7.04
2.73
5.14
                         32

-------
   TABLE 6.   INITIAL  ZINC CONCENTRATION  IN  THE SOIL
             REPORTED BY ZANDE
                                             Zn (%),
                     Sol ids (%)             Dry Basis
Z01                      57.5                 0.1720
Z02                     58.0                0.1717
Z03                     57.8                0.1795
Z04                     58.0                0.1347
Z05                     57.9                  0.1847
                        57.9                  0.17
                        -33

-------
               TABLE 7.   INITIAL ZINC AND  CADMIUM CONCENTRATION
                          IN THE  ZINC/CADMIUM SOIL
                          Zinc  Concentration               Cadmium  Concentration
                           (mg/kg)  dry soil	(mg/kg) dry soil
Sample                    Zande           EPA               Zande              EPA
Feed 1                     1193          1064                976             866
Feed 2                      1052          1064                965              873

                            Average  =  1093                    Average = 920
                                     34

-------
TEST UNIT DESIGN AND INSTRUMENTATION

      The design of the  test  unit was developed primarily to  accommodate  the
 introduction and characterization of the acoustical energy.   The test unit is
 shown in Figure 5.   The  intent  was  to reasonably  simulate  the field conditions
 under which the acoustics would be applied. That  is,  the design was to
 simulate the earth as much as  could be expected in a  laboratory  apparatus.
      Relatively low frequencies  (compared  to Battelle's EAD work) were  chosen
 because lower frequencies are  required  to penetrate the  earth an appreciable
 distance.   The unit was  designed to generate plane-wave acoustics in  which
 points of constant phase form a  plane.   The direction of propagation  is  normal
 to the plane.
      This approach reduces the  acoustics problem to a  one-directional  case.
 In this case, the  acoustic  field can be  characterized  with sufficient accuracy
 with a few point measurements.   This is an  equivalent  situation  to  the
 electric field formed by  the two parallel-plate electrodes.
      The acoustic  instrumentation includes  an  acoustic shaker, a  load  cell,  an
 accelerometer,  and two  hydrophones.   The acoustic  source  is  an Unholtz-Dickie
 Model  1 electro-magnetic shaker.  This  shaker is the source  of the  acoustic
 excitation.   It transmits a  maximum force of 50 Ib. and operates between  10  Hz
 and 10,000  Hz.   A  Sensotec 31/1432-08 load cell  and a PCB-321A02  accelerometer
 mounted on the acoustic piston assembly were used to measure the force and
 acceleration levels.   These  levels  were used to calculate  the mechanical power
 input to the system.   Two B&K  8103  hydrophones were used to  measure the
 dynamic pressure above and below the  test  cell.   Basically,  hydrophone  signals
 indicate the extent of  attenuation.
      Acoustic data were acquired during  testing  with the four  channel
 analyzer.   This was under computer  control  (computer not shown in Figure 6) to
 automate acoustic  data  collection and storage.  Two plots of  typical  acoustic
 records that were  acquired and stored are shown  in Figures 7 and 8. The  data
 in Figure 7 are typical since  the signed traces  from the load cell,
 accelerometer and two hydrophones appear as single-size waves  at  the  drive
 frequency.   However,  in Figure 8, the load cell and accelerometer signals have
 significant harmonic content,  indicating some nonlinear  interaction between
                                        35

-------
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                                                                ACOUSTIC DRIVE?
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C-y-
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                                                                 ACOUSTIC HEAD
                                                                LIQUID SA1PL1NG
   ELECTRODES
S.S.  Scrtfin {TOO  mesh)
                                                               WOOD  BOX
                                                                    SOIL
             Figure    5. Schematic  of Laboratory Test  Unit.
                                    36

-------
Shaker
Load Cell: F
Accelerometer: a
 Piston, Area A
Hydrophone: p 1
   (upstream)
Test Volume
Hydrophone: p2
   (downstream)
Acoustic
Termination

   Power
 Amplifier
                                      Function
                                      Generator
   Four
 Channel
Analyzer
                                      A  -I
  Signal
Amplifier
     Figure 6. Test Unit and Acoustic Instrumentation.
                        37

-------
         10
  FORCE
  NEWTONS
        -10
        40
ACCELERATION
    G
        40

        10
 PRESSURE
 PASCALS
       -10
        10
PRESSURE, H2
PASCALS
        10
                                      TIME, SECONDS
                                                                           IT 02
      Figure  7.   Typical  Acoustic  Signals Acquired During  Testing.
          40
   FORCE
   NEWTONS
         -40
         100
 ACCELERATION
     G
        •100
         20
PRESSURE
I'ASCAI.5
         -20
          4
PRESSURE,  H2
PASCALS
                                       TIVE   Seocncfc
                                                                            0.04
            Figure  8.   Signals  Indicating Nonlinear  Interaction
                          Between Drive  Piston and Soil Column.
                                          38

-------
the driving piston and the soil  column.   Note that the  hydrophone  signals
appear more as sine waves.   This is attributed to the higher  attenuation of
the harmonics as  the  acoustic  signal  propagates  through  the soil before
reaching the hydrophones.

Test Cell

     Two test cells,  3-in.  ID  (internal  diameter)  4.0 and 6.0  in.  height made
of acrylic tubing, were  used to hold the contaminated soil.  The test cell
used for decane  tests was different from those tests of the zinc cell. A
description of the two cells is  provided  below.

Decane Test Cell--
     The test  cell 3-in.  internal diameter  4-in.  height consists of two
electrodes, the  anode on top and the cathode at  the bottom. A schematic of
the decane cell is shown  in Figure 9.   The distance between the  two  electrodes
is 2 in., which essentially is the  sample cake thickness.   The anode is a  3-
in. diameter, 100  mesh stainless steel  screen, whereas  the cathode is  a
perforated s.s  supporting plate.   The cathode is supported by  four  s.s.  rods.
A leachate  collecting chamber  was placed under the  cathode. Leachate from the
soil was drained  through pipes to the leachate collecting pans.

Zinc Test Cell--
     The test cell, 3  in.  (internal  diameter) x 6.0 in.  (height) was designed
for the  purpose of flushing to  maintain  the moisture  content of the  soil.
During the application of the  electric field, electro-osmotic phenomena caused
the water to move from the anode toward  the  cathode. This water movement
would cause the layer  in contact with the anode to become drier and  thereby
causing  less ion movement since  water  is  the  medium  in  which ions transport.
Since a  medium is  required to  transport  ions,  the flushing design was  devised.
     More space was added to increase the distance between the anode and the
cathode  and to  create two electrode-flushing chambers.  The anode-flushing
chamber  is located at  the top  of the anode, whereas  the  cathode-flushing
chamber  is located at  the bottom of the cathode, where  the  leachate  is
                                       39

-------
                                                                               RUBBER
                                                                               GASKET
   THERMOCOUPLE
     TYPE  (K)
                                                                             ANODE (8)
  9.S. ROD
SUPPORT FOR
  SCREEN
                                                                      CATHODE
                                                                      S.S. SCREEN
          DRAINING
                         RUBBER
                         GASKET
POLYETHYLENE THIN SHEET
                                                                        LEACHATE  COLLECTING
                                                                                PAN
                     9.  Side View of  Testing €ei\ for Electraacaastic oViM
                          Decontamination Process Used for Decane Treatment.

-------
collected.   The  distance between the anode and the cathode used  in  the  zinc

experiments is 4.5 in.   The anode is a 3-in.-diameter  perforated  plate

containing  1-mm-diameter holes and is connected to a spring-like  lead to  allow

the anode to  move with the cake and  establish contact.  The cathode  is  a  100-
mesh S.S. screen supported by  an  S.S.  perforated  plate containing 4  mm

diameter holes.   Both screen and plate were supported by  four S.S. rods,  which
criss-crossed  under the  perforated plate,   Schematic of the zinc  cell is  shown
in Figure 10.


EXPERIMENTAL  PROCEDURES


     The following experimental procedure is  used in conducting the
experimental investigation on both zinc and  decane  soil.

          Fill the bottom wood  box with a known amount of saturated sand.

          Bolt the lower  acrylic tubing on top of the  box with a  rubber gasket
          in  between.
         Fill the lower  acrylic  tubing with saturated sand.  The  sand must be
          very wet and compacted  to  ensure  acoustic coupling.
          Place  a polyethylene plastic and rubber gasket  sheet on top of the
          lower  acrylic  tubing.
          Place  the testing  cell  on  top  of the polyethylene plastic  sheet and
          bolt the cell  to  the lower  acrylic  tubing.
         Fill the leachate  collecting chamber with distilled water until
          water starts to flow into the  leachate  collecting  pans.   During the
          zinc tests,  the leachate draining pipes were connected  to a
          peristaltic  pump, which  fed from a 500 ml beaker filled usually with
          about 350-400 mL  distilled  water.    Water level  was always maintained
          below the cathode during both decane  and  zinc tests.
         Place a known quantity of contaminated  soil  in the test  cell on top
          of the cathode  and  leachate  collecting  chamber.
         Place the anode on top of the soil and  exit  connecting wire outside
          the  cell.
         For  the zinc tests the upper part of the test cell was modified for
          flushing purposes (Figure 5).   The modification created a  chamber
          above the anode which holds recycled water.   The inlet  tubing to  the
          chamber is connected  to a peristaltic pump,  which feeds and recycles
          from a 500 mL beaker  filled with about  350-400     deionized water.
         Place a polyethylene plastic and rubber gasket on top of the test
          cell, so that sand at field capacity of 9 percent moisture was
          always  in contact with the  anode.


                                       41

-------
      POLYETHYLENE THIN
           SHEET
          OUTLET
     FLUSHING SOLUTION
(RECYCLED BACK TO INLET)^

              THERMOCOUPLE*
                TYPE  (K)
    S.S  ROD
 SUPPORT FOR
    SCREEN
            DRAINING
             PIPE
LEACHATE
 OUTLET
                                           ANODE FLUSHING
                                              CHAMBER
                                                                                              INLET
                                                                                        FLUSHING SOLUTION
                                                                                            (RECYCLED)
                                                                                ANODE (B)
                                                                           S.S. SCREEtf
                                                                                   CATHODE
                                                                                   S.S. SCREEN
                                                                                    100 MESH
                           RUBBER
                           GASKET
                                                     POLYETHYLENE  THIN SHEET
                                                                                 LEACHATE
                                                                                 COLLECTING
                                                                                 CHAMBER
       Figure 10.   Side View of  Testing  Cell  for  Electroacoustic  Soil  Decontamination
                   Process  Used  for Zinc Soils Zinc/Cadmium Soil

-------
           Bolt the upper acrylic tubing to the test  cell.
           Fill the top acrylic tubing with wet sand.
          Connect  the  acoustic  head to the acoustic  driver  (the acoustic  head
           should  be in contact with the sand) .
          Insert the thermocouple inside the  testing  cell.
          Set  the  appropriate  power input,  acoustic power, and frequency  and
           conduct  the  test  for a given interval of time.
           During  the test,  the  following variables were monitored:   voltage,
           current,  cake temperature,   acoustic  force,  and  acoustic
           acceleration.
      •    At  the  end of the test,  turn off all  the power sources.
          Weigh the treated cake and  liquid  leachate  (zinc anode liquid and
          zinc cathode liquid).
           Save both leachate and cake in glass  jar with Teflon seal ing.
           Quarter  and cone the samples  in case of  decane.  In caseof zinc,
          dry the  sample  at 105 C  and 1 in.  Hg for 24  hours,  grind,  and mix
          the sample.
          Send samples for  analysis.

ANALYTICAL  PROCEDURES

     All  the  chemical  analyses were performed  according to  the methods
recommended in Test Methods for Evaluating Solid Waste,  SW 846  (U.S.  EPA,
1986).   The atomic absorption spectroscopic  method (flame AA - direct
aspiration)  was used to analyze  zinc  and cadmium.  The  zinc  concentrations  in
leachate and  soil  were determined using Method 7950. Cadmium in  leachate and
soil was  analyzed by Method 7130.   For sample preparation, Method 3010 was
used with leachate  and Method  3050  with soils.  The samples were digested
using nitric  acid, hydrochloric acid, and  hydrogen peroxide. The analyses
were performed on  Perkin-Elmer Model  5000AA using an oxidizing air/acetylene
f 1 ame.
     Decane analyses were performed using  gas  chromatographic  methods.
Soxhlet extraction procedure  (Method 3540 in SW 846)  was used in the  sample
preparation and during extraction of decane from the soil.  Here,      v/vmix
of pesticide-grade hexane and  acetone was used  as the extraction solution.
Extracts  were concentrated  using the  standard  Kuderna Danish apparatus.  The
                                       43

-------
 analyses were performed on  a Hewlett-Packard Model 5890A  gas chromatograph by
 flame  ionization detection.    The  column  used  was Supelco SPB-5,  30 m  long, 0.5
 mm  ID, and 1.5 ppm  phase  thickness.   The temperature  program was 100 C
 initially and ramped at  10  C/min  without initial hold.  Once the temperature
 reached  250  C,  it was  held for 10 min.   The  injector  and  detector  temperatures
 were 230 and 250 C, respectively.   Carrier gas  and flame  ionization  detector
 make up  gas  were nitrogen.  Combustion support gases  were  air and hydrogen.
 Sample injection volume was  1 ml and was performed by an HP  Model  7673
 autoinjector.   Data were  collected by an  HP Model  3396  integrator.
     All  the chemical  analyses were performed by Zande  Environmental
 Laboratories,  Columbus, Ohio. For quality-control purposes,  some  samples from
 the same batch  were sent  to  the U.S.  EPA's  Risk Reduction Engineering
 Laboratory for  chemical analyses.
     The  soil  samples  were analyzed for  particle-size distribution,  as
 recommended  by V.  J.  Kilmer  and L. T. Alexander  (1949,  Methods of  Making
Mechanical  Analyses of  Soiis.   Soii Science  68:15-24).   Each soii sample was
dispersed  in a  sodium hexametaphosphate  and  sodium carbonate solution.  The
<20 p,  <5 fl, and  <2 p fractions were determined  by pipetting  after
sedimentation.   The <0.2 p fraction was determined by pipetting  after
centrifugation.    Sand  was separated from silt and clay  by  washing  the sample
through  a  300-mesh  sieve.   The various sand fractions were determined by dry
sieving  and  weighing.
     Organic carbon content  in soil was determined by the  dry-combustion
method.   This involved  combusting approximately  2 gal.  of  soil at  900-950 C in
oxygen gas stream.   Carbon dioxide generated  was absorbed  by ascarite bulb.
The organic  carbon  content in soil was estimated from the  amount of C02
generated.
                                       44

-------
                                     SECTION 5
                              EXPERIMENTAL RESULTS

      Batch experimental results for  both  decane and zinc are discussed  below.
 The following BSD parameters were  investigated.
           Effect  of  electric field on decane  mobility
           Effect of voltage  and time on decane removal
           Effect of acoustic power and frequency.

DECANE EXPERIMENTAL  RESULTS

      A total of 30  decane  tests were conducted to establish the technical
 feasibility  for decane removal  via  BSD.   Tests 1 through 9 were shake-down
 tests.   For  Tests 10 through 25, the treated  soil samples were mixed
 thoroughly and sent  for analysis to both labs. These  tests were desiigned to
 monitor  the  decane  removal.  Results are shown  in  Appendix A.  Tests  26
 through  30 were designed to  monitor  the decane mobility and removal.   The
 treated  soil samples for each test were divided  into  three  layers  (F igure 11)
 Then each layer was  quartered as shown in Figure 12.  Two quarters were sent
 to  the U.S.  EPA laboratory and  the  other  two  quarters were  sent to  Zande
 Laboratory.

 Initial Decane Concentration

      The soil sample was contaminated at  Battelle by adding 8 weight percent
 decane,  dry  basis  (D.B.)  into the soil.   However,  since the soil  favors the
 absorption of water  over decane and  since the soil  was saturated  with water,
 all  of the 8 percent did not go into the soil.  Five soil-decane  samples  were
 taken from the mixture for laboratory analysis. Soil  analysis  by Zande Labs,
 Columbus,  Ohio, showed  an  average of 5.14 percent  (D.B.)  present  in the soil.
 However,  Test 15  (control    no  BSD)  soil  shows 6.42 percent decane  for  the

                                       45

-------
Cathode (-)


J o,.
Section A

1 0.5"
Section B

J 0.5"
Section C
  Figure      Side "View"of the Treated ESD Cake    Decane Tests
              (26D, 270   28D   and 300} Showing  the Three
              Analyzed Layers
      Figure      Top View    Decane  .ayer Showing How the
                  Layer Was Divided ana Analyzed

-------
 same mixed soil  analyzed by the same  laboratory.  This discrepancy  in  the
 initial decane concentration  in  the soil made subsequent data  analysis very
 difficult.   Test Sample 15D (control)  was  analyzed by both Zande Labs  and  the
 U.S.  EPA Laboratory.  The analytical results were 6.36 and  6.48,  respectively,
 Since the laboratory analysis on  decane  concentration for Test 15 match the
 U.S.  EPA decane analysis,  it  was decided to take the Test 15  decane
 concentration  as the reference for  initial  decane concentration in the  soil.
 Table 5 shows Zande Labs  data for initial  decane concentration in the soil
 before correction and after correction.   The initial solids content  of the
 decane soil  was 52.8 percent.

Effect  of Electric Field on Decane  Mobility

      When a d.c. electric  field  is  imposed  against  a porous  soil medium,
 migration of water  occurs toward the  cathode. This phenomenon, called
 electro-osmosis, refers to the migration of ions that have the ability to
 compensate  the charges on  the soil  toward  the opposite charged electrodes.
 Water is transported during this  phenomenon by ions because of viscous
 interactions,  water of  hydration, and  molecular  collisions.   We  hypothesized
 that, since decane  is hydrophobic and  lighter than water, the decane would co-
 transport with water  during electro-osmotic  transport.  However, our
 experimental  results do not completely validate  this theory.   However,  as
 shown in Table 8, results  of  Tests  26  through 30 indicate that there seems to
 be a  trend for the movement of the  decane  from the top anode layer toward  the
 cathode layer  and the movement of water  is  also  in  the same  direction.   Thus,
 the results indicate that  there  is  a potential for  the transport  of organics
 in aqueous suspensions  in the presence of  d.c.  electric fields. This  effect
 can possibly be further enhanced  by using  appropriate additives, such as
 dispersants  used  in tertiary oil  recovery  by the petroleum industry.

Effect of Electric Field and Time on Decane Removal

      The following  electrical  and time parameters were investigated:
      •   Voltage (0,  12.5, 25,  37.5,  V/in.)
           Time  1.25,  2, 24.0 hours).
                                        47

-------
           TABLE 8.   EFFECT OF  ELECTRIC FIELD ON THE  DECANE  MOBILITY
                       Acoustic            EPA   Decane     % Decane Removal
Test Voltage         Power                   (%)      Layer A   Layer ()
 No.    volts/in.        Watts      layer    Wet  Basis              Layer  A   x


 26      -37.5             0      Layer A      4.45                   0
                                 Layer B      4.3                    3.49
                                 Layer C      3.9                    12.36

 27      45               0      Layer A      4.35                   0
                                 Layer B      4.17                   4.16
                                 Layer C      3.56                   18.16

 28-25               0      Layer A      4.29                   0
                                 Layer B      4.07                   5.13
                                 Layer C      3.34                  22.14

 30     -37.5             0      Layer A      4.44                   0
                                 Layer B      3.90                  12.16
                                 Layer C      3.54                  20.27
                                     48

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The analytical  results for decane tests  were inconsistent. Zande  Lab analyses
for decane concentration  in  soil  samples  were higher than those of the  U.S.
U.S. EPA. This  inconsistency made it  difficult to reach a  firm conclusion
about the percent  decane  removal  resulting from the electric  field on BSD and
time.   However,  based on the tests  (140, 15D,  170,  21D, 22D, and 230)  in which
the decane values  from the two labs were  relatively close,  the data  indicated
about 10-25  percent decane removal.   For  example, Test  15D  (control test, no
BSD) showed an  average 6.42  percent  decane in the soil, whereas  Test  17D (in
which the electric field/acoustic was  applied at 12.5  V/in. , 0.6 W, 2  hour)
showed a  decane removal of 20.25 percent  (from  Zande)  to  25.7 percent  (from
U.S. EPA  Laboratories).   The average of the  two analyses  is 22.9 percent
decane removal.    Since most  of the tests were done for  a short time (less than
25  hours), one  expects a  larger decane removal  if BSD were  applied for longer
periods  with the  flushing and added  dispersant. However,  more tests are
needed to validate the above assumption.

Effect of Electric Field  on Soil Moisture Content

     The  electro-kinetic potential across the  soil  is the driving force  of
electro-osmotic  dewatering.   As  discussed previously, water moves  from the
anode toward  the cathode.   This  movement  of  water  causes  the moisture  content
of  the soil to  change.   The layer in  contact with anode is  always drier. This
phenomena can be seen clearly  for the decane  soil  Tests 26D, 27D,  28D, and
300. For  example,  in Test 27, the cake in contact with anode  had  a moisture
content of  27.35 percent,  the cake between the  anode  cake  and the  cathode cake
had a moisture  content of 38.76 percent, and the cake  in  contact with cathode
had moisture  content  of 49.42 percent.   The  initial  moisture content for the
soil before BSD treatment was 47.32 percent.    Figure  13 shows cake moisture as
a function  of cake gradient.

Effect of Acoustic Field

     The  analytical  results for  the decane tests had  high variability, as
mentioned earlier.   Therefore, the effectiveness of the electric  fields  with
                                        49

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  Anode  (+)
Cathode  (-)
                             27.35
                            38.76
                            49.42
     Figure 13.   Side View of Decane-Treated BSD Cake
               Showing  Layer Moisture  Content.
                            50

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 or without  an acoustic field is difficult to accurately detect.  The highest
 estimate  of removal  is 30 percent.   Acoustics has  always  been applied as an
 enhancement  to  electric field in which the  rate  of removal is increased with
 some  increase of overall  removal.   But,  because  of the low removal rate of the
 electric  field  and high variability of the  analytical  results,  and the fact
 that  no  rate information was obtained, no  acoustical  effects  can be observed.
      This is not to say there is no acoustic effect;  there  indeed may be  a
 positive  effect,  but  it cannot  be "observed"  in  the relatively few number of
 tests  with  highly variable results.

Statistical Analysis on Tests  26D-30D

      A statistical analysis was performed on Tests 26 D-30D laboratory result
 from  both U.S.  EPA and Zande Lab.   Analysis  shows  that there  doesn't appear to
 be  any relationship between the decane concentration  measured  by the two
 laboratories.   The correlation  between the  15  measurements made between the
 two  laboratories was  calculated to  be 0.233. A  correlation of zero would
 indicate  that there is no  linear relationship between the two measurements,
 whereas a correlation  of 1 or -1 would indicate  that  there is a perfect linear
 relationship between  the  two sets  of measurements. The sample correlation of
 0.233  was not statistically significantly different from  zero;  thus,  there is
 no  relation between the two  laboratories'  data.  Moreover,  a statistical
 comparison  of the decane concentration measured  by the two laboratories shows
 that  the  measurements  made by Zande tend to  be an  average 2.94 percent higher
 than  the  measurements  made by the  U.S.  EPA.
      The  95 percent confidence interval  for the  average difference in the
 measured  decane concentrations ranges  from 2.35 to 3.53  percent. This means
 that  we are 95 percent confident that  individual differences between U.S. EPA
 and Zande measurement fall between a minimum difference of 2.35 and a maximum
 difference  of 3.53 percent.  Table 9  shows statistical regression output for
 each  test and an overall  regression output  on  all  the measurement points in
 Test  26 through Test  30.   The statistical  output (standard error of estimate,
 number of points used, standard error of coefficient,  and root mean squared)
 show  a very poor correlation between  U.S.  EPA and Zande data.  For example,
                                        51

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TABLE 9.   STATISTICAL  ANALYSIS RESULTS  FOR  DECANE TESTS
Decane Results
Test Number
26DA
26DA1
26DA2
26DB
26DC



27DA
27D8
27DC





28DA
28DA
283B
283C




EPA (%)
5
5
6
6
6



5
6
7





6
6
6
5




.38
.29
.04
.07
.29



.99
.81
.04





.10
.10
.20
.58




Zande (%) Statistical Regression Output
9
8
7
8
8



8
8
11





8
10
7
10




.11
.89
.90
.40
.92



.91
.51
.64





.43
.31
.59
.49




26D Regression
Constant
Std Err of Y Est
R Squared (Adj , Raw)
No. of Observations
Degrees of Freedom
Coef f icient (s)
Std Err of Coef.
27D Regression
Constant
Std Err of Y Est
R Squared (Adj , Raw)
No. of Observations
Degrees of Freedom
Coefficient(s) 1
Std Err of Coef. 2
output :


- .019976


.530103
5521724
output :


.333129


.785111
.523948

11.72677
.4968266
.2350181
5
3



-2.11666
1.972165
.3334356
3
1


28D Regression output:
Constant
Std Err of Y Est
R Squared (Adj , Raw)
No. of Observations
Degrees of Freedom
Coefficient(s) -3
Std Err of Coef. 2


.2280125


.50094
.549209
30.18886
1.248483

4
2


                          52

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                              1-ABLE 9.   (CONTINUED)
                  Decane  Results
Test Number     EPA (%) Zande (%)
                          Statistical Regression  Output
30DA
30DB
30DC
6.02
5.73
5.77
8.27
8.73
8.36
300
Constant
Std Err of
Regression

Y Est
output :



-15.17859
.2439200
                                    R  Squared  (Adj,  Raw)
                                    No:  of Observations
                                    Degrees  of Freedom
                                           .0346422
                                    Coefficient(s)
                                    Std Err  of Coef.
                                         -1.15202
                                         1.112784
                                               .5173211
                                                       3
  MEAN
  S.D.
6.03
 .45
8.96
1.04
Regress i on output:
OVL DRY
Constant
Std Err of Y Est
R Squared (Adj, Raw)
No. of  Observations
Degrees of  Freedom
                                                            -.018986
                                     Coefficient(s)    .5307563
                                     Std  Err of Coef.     .6173460
                         5.764438
                         1.081622
                         .0537989
                                15
                                13
                                                Regress i on output:
                    26DA
                    Constant
                    Std Err of Y Est
                    R Squared  (Adj,  Raw)
                                                             .8587125
                                               10.86250
                                               .1539435
                                               .9293563
                                     53

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0.0537  root  squared  (raw)  for the overall data  shown  at  the end of Table  8
indicate  that  only 5.37 percent of the  data  fit the correlation.   The
difference between the U.S.  EPA measurements  and Zande measurements and their
descriptive  statistics are contained in Table  10.  Also,  Figure 14 shows  Zande
measurements against  U.S.  EPA measurements.

PC Assurance of Analytical Data:  Decane

          All the  analytical  data for decane  in soil  samples used in the  BSD
tests are given  in Table  11.   It is apparent  that the analytical  results were
inconsistent for the  two  laboratories.   For  example,  the variation of
interlaboratory  results ranged from  0.62  to 64.71  percent.  However,  the
quality control  tests performed by both laboratories  indicate significant
precision and accuracy  of  their data.   For example,  Sample 26DA was analyied
in triplicate  by both  laboratories  (see Table  10). Percent variations were
»8.5  and »5 for U.S.   EPA and  Zande Laboratories, respectively. Recovery data
given in  Table 12  show that  the average percent  recoveries  were within  75  to
125  percent.   Because of  these conditions, it is difficult to determine the
inaccuracies in  analytical results.   The  differences  in  interlaboratory
analytical results may  be  attributed to oversaturation of samples with decane,
nonuniformity of sample,  incomplete  mixing,   and differences in laboratory
analytical execution.   Consequently,  it was decided to use only the analytical
data that have interlaboratory variations of less than 15 percent to determine
the effectiveness  the ESD  process  is  in decane  removal.
     It  is recommended that  further  investigations  be  conducted by U.S.  EPA to
improve the  analytical  methodologies  for organic  contaminants in  soil  samples.
Inconsistencies  in analytical  results as indicated  in our  study can have a
significant  impact in the  development of  innovative treatment processes and
improvement  of existing treatment  technologies.
                                       54

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1-ABLE 10.   EPA AND ZANDE MEASURED  DECANE  CONCENTRATIONS
           AND  THEIR DIFFERENCES IN  SOIL  (DRY  BASIS)
Test Number
26DA
2 6 DAI
26DA2
26DB
26DC
27DA
27DB
27DC
28DA
28DA
28D8
28DC
SODA
30DB
30DC
Number of
Samples
Minimum
Maximum
Mean
Standard Dev
EPA
(%)
5.380
5.290
6.040
6.070
6.290
5.990
6.810
7.040
6.100
6.100
6.200
5.580
6.020
5.730
5.770
15
5.290
7.040
6.027
0.468
Zande
(%)
9.110
8.890
7.900
8.400
8.920
8.910
8.510
11.640
8.430
10.310
7.590
10.490
8.270
8.730
8.360
15
7.590
11.640
8.964
1.071
Difference
(%)
3.730
3.600
1.860
2.330
2.630
2.920
1.700
4.600
2.330
4.210
1.390
4.910
2.250
3.000
2.590
15
1.390
4.910
2.937
1.064
                         55

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     12.0
      11.5
      11.0
     10.5
     10.0
      9.5
      0.0
      0.5
      8.0
      7.5
      7.0
      6.5
      0.0
      5.5
      5.0
 1
5.0
*
*
  **
                             5.5
        0.0
                  0.5
7.0
7.5
                                                         EPA
FIGURE  14.    Zande Measured  Decane Concentration Plotted Versus U.S EPA  Measured Concentration-

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           TABLE 11.   COMPARATIVE  ANALYTICAL DETERMINATION  OF DECANE
                       IN SOILS  BY  U.S. EPA AND  ZANDE LABORATORIES
Test
No.
10D
11D
12D
13D
14D
15D
17D
19D
20D
21D
22D
23D
26DA*
26D
26DC
27DA
27DB
27DC
28DA
28DB
28DC
SODA
30DB
30DC
EPA Decane
Concentration
Dry Basis
1.17
4.23
2.77
4.79
4.78
6.48
4.77
4.93
4.98
5.6
5.28
6.22
5.57
6.07
6.29
5.99
6.81
7.04
6.10
6.20
5.58
6.02
5.13
5.77
Zande Decane
Concentration
Dry Basis
5.46
5.59
5.14
5.08
5.63
6.36
5.12
3.75
3.57
6.1
6.75
6.58
8.64
8.40
8.90
8.91
8.51
11.64
9.37
7.60
10.49
a.27
a.73
8.36
Percent Variability
Zande and U.S. EPA
64.71
13.85
29.96
2.94
8.17
0.62
3.54
13.59
16.49
4.27
12.22
2.81
21.60
16.10
17.18
19.53
11.09
24.63
21.14
10.14
30.55
15.75
25.97
la.33
"For example, percent variability was  calculated as  follows:


        For  10D    5.46  -1.17'    1Q()  = 647%
                    O.4b +  L.Li
                                     57

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                     TABLE 12.QC  DATA FOR EPA  ANALYSES
                   Amount Spike         Amount  Spike       Percent
Sample ID          Added (ppg)          Removed (ppg)        Recovery


   14D                 10,000                7,700              77
                      10,000                7,300              73  (duplicate]

   19D                200,000              202,000              101
                     200,000              165,200              82.6 (duplicate)
                                   58

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ZINC TESTS

      Results of zinc  tests,  background on electro-chemical reactions of zinc
 at electrode and other related  discussion  is  presented in the following
 paragraphs.

 Results  of  Zinc Tests

      A total of 16 tests were conducted  on the zinc-contaminated soil.
 Results of these tests are shown in Appendix B.  The first six  tests (IZ-6Z)
 were conducted to establish the standard procedures,  such as flushing or
 sectioning;  for example,  no sectioning was used in  Tests  3-4.
      The treated soil was mixed (cake  in contact  with anode  was  mixed with
 cake in contact with cathode) and sent for lab analysis.   Lab analysis did  not
 show any zinc removal.   However,  in Tests  5-6,  the  treated cake  was divided in
 half (cake in contact with  anode  and cake in contact with cathode).  Results
 show that over 80 percent average removal  of  the  zinc was achieved in the
 anode layer and some zinc accumulation in  the  cathode  cake.

 Backsround  on  Electra-chemical  Reactions
 of Zinc at the  Electrode

      During the application of  d.c. electric  field,  electrolysis of water in
 the soil occurs with the following reaction  H20  A  H+ + OH". The (OH)  ions at
 the cathode combine with cations  to  form appropriate compounds  based on  their
 relative concentrations.   Simultaneously,  the  pH  at the cathode  increases.
 The zinc accumulation around the  cathode is due to an increase  in the soil  pH.
 Zinc is soluble at pH below 6.   Above  pH 6, zinc would exist as Zn(OH)2
 ZnOH+, ZnOHCl, and Zn02, which are insoluble  in water. Since  the soil around
 the cathode  is  basic (pH value  of 9-11), the zinc will  precipitate in the
 layer around the cathode.    Figure  15  shows the solubility of zinc as a
 function of pH.   The diagram shows  zinc ion Zn+  become  insoluble at pH
 between 8-9.   Also, we have calculated the percentage of zinc ions and their
 complex forms at different  pH.   The calculations were performed using the
 geochemical computer code  MINTEQA2 (developed  for  U.S.  EPA,  1988).  The code
 calculates the distribution of  chemical  species  (ions, neutral  species, and

                                        59

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Figure 15.
The Amphoteric Nature of ZnO 1s Revealed In the Variety
and Solubility of the Ionic Species, which the Oxide
Displays on Dissolving 1n Water at Various pH
                    60

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 ion-pairs) in a water system  for total analytical concentration,  pH, and Eh
 data.   In addition, the code  may  be  used  to compute  in detail the changes in
 fluid  composition,  the  identity  and  the extent of precipitation or  dissolution
 of secondary  minerals.   Table  13  shows calculation for percent distribution  at
 pH 6 and  9.7.   A more detailed analysis is listed in  Appendix C.  Since there
 was zinc  accumulation in the  cake toward  the  cathode,  it was decided to divide
 the BSD treated soil into the  following four  sections:
     •     ZA  - Soil in contact with  anode (1  in.  thick)
           ZD  - Soil in contact with  anode layer  (1  in.  thick)
           zc  - Soil in contact with  cathode layer (1  in.  thick)
           ZB  - Soil in contact with  cathode (1  in. thick)
A  schematic of the  four sections  is  shown  in  Figure 16.   Also,  it was observed
 in Test 3 and 4 that the moisture content of  the  layer  in  contact  with  anode
was always decreasing,  thereby, reducing  the  ion transport efficiency. Hence,
 it was  decided to  modify the test cell so the anode layer  can  be  flushed  with
water to  maintain  its  moisture consistency and, thus,  to provide  a transport
medium for the  zinc ions.   A schematic of the  modified  cell  is shown in Figure
 10.
    The following  BSD parameters were investigated:
     •     Leaching  time
     •     Electrical  power
           Acoustic  power
           Acoustic  frequency.
A mass balance on  Test 16Z is shown  in Table  14.  Mass balance data  show  that
all of the zinc was accounted  for.   Initial zinc  weight  in the soil  (before
BSD) is 0.818 g whereas total zinc weight in  cake layers and  leachate  after
BSD totaled 0.819 g.   No zinc was lost, which  correlates well  between
experimental  and analytical data  for that  test.  Only Test 16Z leachate was
sent for analysis.    Other  tests mass balance might show  loss  resulting from
analytical variation.

Effect of Time on Zinc  Removal
     The BSD  time  is one of the critical parameters  for  the  zinc ion removal.
Figure 17 shows percent zinc removed as a function of cake gradient for 25 and
100 hours at  power input of 0.510 and 0.390 W,  respectively. The data  shows
                                       61

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 TABLE 13.   PERCENT IONIC  DISTRIBUTION FOR ZnCl2
             AT PH 6 AND 7
                   oH6
                              oH  7
                          Percent  Distribution
Zn+2


cr


H20



u+l
 94.0 Zn+2
  5.7ZnCl +

 96.7 Cl'1
  3.1  ZnCl+

48.9 ZnOHCl
 50.1  ZnOH+
              48.9 ZnOHCl
              50.1 ZnOH+
73.9  Zn(OH),
 25.3 Zn(OH)3-
99.9 Cl
        -i
  1.5 OH-
 64.2 Zn(OH),
 33.0 Zn(OH)3-
  1.2 Zn(OH)4

 15.25 ZnOHCl
 17.83  OH'
 13.42  ZnOH+
 17.83  Zn(OH)2
 17.83  (OH)
 17.83  Zn(OH)4-2
                     62

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Gradient
         Anode   (+)
           Cathode  (-)
                                   Layer  in Contact with Anode

                                              ZA
                                Layer in Contact with Anode Layer

                                              ZD
                                        Layer  in Contact
                                      with Cathode Layer
                                  Layer  in  Contact with Cathode

                                              ZB
    Cake After BSD
    Process
    (4 "-4.5"  thickness)
J
                   Figure  16.   Schematic  of  the  Cake-Divided
                                 Sections  for  Test 7Z-16Z.
                                          63

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           TABLE  14.   SAMPLE MASS BALANCE  AROUND THE ZINC  FOR TEST #16Z
   Cake Before BSD
                                                  Cake After BSD
      Grains Dry Soil
          485.52
        Grains Zinc
          0.8181

Anode (+]
0

1
BSD





2

3

4

Grams Dry Soil
114.49
Grains Zinc
0.0266
Grams Dry Soil
123.39
Grains Zinc
0 .03977
Grains Dry Soil
127.36
Grains Zinc
0 .06729
Grans Dry Soil
119.68
Grams Zinc
1.628
                                         Cathode (-)
                                                                       Percent
                                                                     Zinc Removed
                                                                        100
                                                                        -68.63
Accumulated
  211.5
                        Zinc weight in leachate = 0.0577 g
Mass Balance Around the Zinc

Initial zinc concentration in the  soil =  0.001685 g  zinc/g dry  soil

Zinc  weight  in  the soil before BSD  =  485.52 x 0.001685
                                     = 0.818 g
Zinc  weight in the cake after  BSD =     (114.49)   (0.0002325)  +  (123.39)
                                           (0.0003223)  +  (127.30)   (0.0005286)
                                           (119.68)   (0.005248)

                                     =  0.02662 + 0.03977 + 0.06729 + 0.62808

                                     =  0.76176

Zinc  weight in the leachate after BSD = 0.0577 g

Total zinc weight after BSD = Zinc weight  in the  soil and zinc weight in
leachate.
                                        =  0.76176 + 0.0577
                                        = 0.819 g
                                        64

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 o
 X
 X
txl
O
c
r-j
c

    O
    O)
    DC
    o
    c
    •I—
    IVI
     
-------
the longer the BSD  time,  the  higher the zinc removal in all  layers except  the
layer adjacent to the cathode. For example,  in cake gradient 1, at 100 hours,
there was 86.2 percent zinc ion removal,  whereas at 25 hours in the same  layer
under similar experimental  conditions,  zinc ion removal was 63 percent.
     In  cake gradient  2  at  100 hours,  the percent zinc removal  was 80.87,
whereas at 25 hours,  the percent zinc removal was only 4.5 percent.  Table 15
shows a  schematic  of  comparative  actual  concentrations  of zinc  ions in each
cake gradient.   During the  25-hour  run , approximately 1063 ppm of zinc was
transported across the cake length.   However,  during the  100-hour run, the
total amount of zinc transported was 1485 ppm.   This suggests that it took 75
hours to transport  the extra 322 ppm from cake gradient number 1.  From the
figure,   it can be  inferred  that the transfer efficiency of  ions decreases  with
increasing time.   This perhaps  may  be  due to dynamic changes in the
concentration of those ions in that particular cake gradient.  Conventional
techniques such as  pump  and treat normally  require 2-3 years for an acceptable
cleanup  period in a sandy soil   Treatment  time of 100 hours to reduce the
concentration levels to  less  than 85  percent by BSD appears  extremely
beneficial.

Effect of Average Power  on  Zinc Removal

     As discussed  earlier in the decane section,  electro-kinetic potential
across the contaminated  soil  is the driving force for  electro-osmotic rate.
The current that  is created by this potential is a function of electro-kinetic
property of the material,  such as  conductivity  and pH. Both current and
voltages have a  significant effect on zinc  ion  removal. Data in Figure 18
show the higher  average  power  consumed,  the more zinc  was  removed  in  each
layer at constant  BSD time  at cake gradient 1 and 50 hour  BSD  (one  inch from
the anode).   A total  of  89.73  percent zinc was removed at  an average consumed
power of 0.811 W  whereas at 0.114 Watts,  60.18 percent of  the zinc was
removed, and, at  0.013 W, 30.25 percent  zinc  was removed. Moreover, the  data
clearly  indicate that  zinc  ions are accumulating at the cathode because of the
high alkalinity of the  soil  (pH 9-11). Figure 19 shows actual zinc
concentration as a  function of cake gradient at three  average powers for  50-
hour tests.   For  the  100-hour tests, much higher  zinc removal was achieved at
a power of 1.423 W  than  at  power  of 0.390.   However, the  efficiency  (kW/equiv.

                                       66

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TABLE 15.  ZINC  CONCENTRATION AT  DIFFERENT CAKE
            GRADIENT FOR  DIFFERENT LEACHING TIME
Electric Time (hours)

0 Anode (+)
1
2
3
4 Cathode (-)
0

1685
1685
1685
1685
25
Zinc
622
1608
1471
2965
50
Concentration (ppm)
166
585
1858
4513
100

232
322
528
5250

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            •o
            O)
            Ol
            ce
            O

            
            D-
 0
 10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
                  Anode (+)

                          Figure 18.
                           control No ESD (0 watts)
  —  T                      f                      j          ._

     1                      2                      3


                 CAKE GRADIENT,  INCH


Variation of Zinc (Wt%) Removed/Accumulated as a Function
 of Cake Gradient  for 0, 0.013, 0.144, and  0.811  Average
 Power Input  for 50 Hours'  Leaching  Time.
                                                                                                  Cathode (-)

-------
en
ID
                10
                           Figure  19.   Variation  of Zinc Concentration as  a  Function of Cake
                                        Gradient at 0.013,  0.144,  and 0.869 W Power  Input
                                        for 50 Hours' Leaching  lime.

-------
ion) of removal  was better at a  low  power that at high power.   Figure 20 shows
percent  zinc  removal for  100-hour tests.

Effect of Acoustic Power and Frequency on Zinc  Removal

     The data  from  the zinc results was processed  to  determine the average
input power into the soil  column.   First,  the  power was determined  at the
sample points  acquired  during  the test.   A typical result  is  shown  in Figure
21.   The results are fairly constant up to record number 50.  At that  point,  a
slightly lower power  is being  impressed  on the column.  This  change is due to
the need to periodically add more soil  to the  top  chamber  as  consolidation
occurs.   The sample  powers were  averaged to obtain the overall  average input
power for the test.   These are the  values  that appear in the  table  of results.
     The data  from  the zinc tests appropriate for the evaluation of the
acoustic effect is  shown in Table 16.   The results from five  tests  are
included along with the parameters that describe the test. Four zinc
concentrations are shown  for each test.   These are the values in  the four
layers taken from each  sample  after the  test.
     The data  from  the three tests  with acoustics, Test 12Z,  14Z, and 15Z, is
compared to the  control test of  11.   The results are compared for each layer.
Layer 4  is not considered because the method of  zinc removal  at the cathode
had changed between the  control, Test  11, and  the acoustic tests.  This
allowed a total of  9 removal  rates  to be  calculated, which are attributed to
the addition of the  acoustic fields.
     The most  interesting and  encouraging  results are obtained  for  Layer 3.
For the  two cases with frequency  of 400  Hz and power levels of  0.44 and  0.86
W, there is an additional removal of 17 percent. Even if the estimate of the
concentration  of the control  was estimated low by 100 rag/kg and the
concentration  of the acoustic tests were  high by 100 rag/kg, the removal  would
still be 6 percent.
     The results from Layer No.  1 are  inconclusive.  The numbers  are all very
low and similar.   They only differ by a maximum  of 50 mg/kg,  which is on the
order of the  accuracy of the  analytical methods. Therefore,  there  is no
statistically  significant  difference.
                                       70

-------
ct:
 vj
Q.,
         50
          Anode (+)


                gurc 20
                   Cake gradient  Inch
  tion
1 432
if Z
and
                                                                           -
  Ranoved  Ht%] as;     unction
.390 M for 100 Hours   Leachiny   IK
ad wt

-------
                                    TEST 14Z
CO
o
LU
^
o
Q_
0.9


0.8 -


0.7


0.6 H


0.5


0.4


0.3


0.2


0.1
       0
          0
        20                 40


            RECORD NUMBER

Figure 21.  Acoustic Input Power Versus Record Number.
                                                             60

-------
                               TABLE  16.  ACOUSTIC DATA FOR ZINC EXPERIMENTS
Test Number
Ave. Electrical power (ff)
Voltage Field (V/in.) 1
Treatment Time (hours)
pH Leaching
pH Leachate
Frequency (Hz)
Power (W)
Zinc Concentrations (mg/kg)
Layer 1
Layer 2
Layer 3
Layer 4
Additional Removal with Acoustics
w.r.t. Test 7Z
Layer 1
Layer 2
Layer 3
Layer 4
7Z
0.869
.4 4.3
50
3.56
11.65
0*
0*

180
687
1847
5644


- + -
__.
—
12Z
0.733
1.3 4.3
50
3.92
12.39
4.00
0.86

205
1418
1524
4479


-14%
-200%
+17%
NA
14Z
0.730
1.1 - 8.17
50
3.36
10.32
850
0.23

166
585
1858
4513


8%
15%
0%
NA
15Z
0.811
1.2 - 4.3
50

8-11
400
0.44

173
644
1532
4054


4%
6%
17%
NA
13Z
0.144
0.8 - 2.0
50
4.06
11.7
0
0

671
1206
1185
2185


NA
NA
NA

*  Not appl  cable.

-------
     Layer  2  has  mixed results.   There  is  a  -200 percent additional removal
for Test  12Z with acoustics.   This dramatic value  is  due to the high
concentration of zinc  in  Layer  2.   The  values  for Test 122  do not smoothly and
continuously  increase as would be  expected.  Rather,  the values plateau for
Layers 2 and 3.   A  repeat analysis  of the sample for  Layer  2  was made and it
was very close to that reported  in  the table.    It was therefore not  a  problem
with the analysis.   The only explanation offered is that the  sample was not
continuous  or  homogeneous  during  the  test.
     The result  for Layer 3, Test  142,  showed no additional  removal. The
major differences between  this  acoustic  test  and the  other  acoustic tests were
the frequency  and power.   The power was only 0.23 W compared  to 0.44 and 0.86
W for the other tests.   The frequency was also twice  as  high  at 850 Hz
compared to 400 Hz.   Therefore,  the lack of removal  is probably attributed to
the lower power  level  and higher frequency.
     The main  observation that can be made regarding  the testing is that much
more is needed.   The analytical  results  have a high degree  of variability.
The samples themselves  may  change over treatment  time  so  that  they  do not
behave as a continuous  medium.   These factors contribute  to the scatter in the
results, which makes the  accurate  determination of the BSD  effect  difficult.
As more and more  tests are conducted,  the confidence  in  the results would be
improved.
     Questions arise as to the importance of the acoustic field even given
that there  is  a  demonstrated significant  increase in removal.  First, over a
fixed treatment  time, a greater removal may be observed. However,  the
question is whether  there  is a lower  limit to  the remaining concentration that
can be removed in the presence  of the electric field  with or  without
acoustics.   If there is a lower limit, then the application of the acoustics
could only  shorten  time and/or reduce total  energy costs.  Given this
scenario,  one  would  have  to trade-off treatment  costs  (energy  and  time) versus
the capital costs and difficulties  to incorporate  the acoustic fields.
     Other  benefits  that  may be obtained with acoustics  is  that the treatment
zone may be increased;  i.e.,  for a given placement  of electrodes for the
electric field, the  treatment volume  may significantly  increase.   This would
certainly represent  a greater benefit of the  BSD system. This concept has not
been tested with  the laboratory apparatus  used in this project.
                                       74

-------
     Secondary  benefits to the acoustics may also exist. For example,
acoustics may help  to  keep permeability of the soil high,  because  the
contaminants concentrate at the removal well.  Continuity of the electric
field  in situ may also improve with the application of the acoustics. Only
with further testing,  including large-scale field testing,  can  these questions
be answered.

ZINC/CADMIUM TEST

          One test  was conducted on the zinc/cadmium  contaminated  soil  using
the zinc-modified test  cell.   The objective of the  test  was to demonstrate
that a mixture  of ion  contaminants  in the soil can  be  transported  in the
presence of electric field.   Results of test are  shown in Table 17 and details
of the results  are provided in Appendix D.  The test was  conducted at a
constant current of 50 mAmp and an  average power of 1 913 W for 100  hours.
The anode  layer was flushed with 0.03N acetic  acid  solution.  Acetic  acid  was
used because it  increased  the  solubility  of zinc and cadmium in the  soil.
Acetic acid forms a zinc acetate complex and a cadmium acetate  complex in the
presence of zinc  and cadmium.   These complexes are  soluble  in water  even at  a
pH higher than  6  (pH 2-9).   The formation of these  acetate  complexes will
reduce the  formation of hydroxide  complexes,  which are insoluble in  water.
The treated cake was divided  into five layers. A schematic of  the five
sections is shown in Figure  22.   During zinc tests, the  treated cakes were
divided into four  layers.   The last layer (Layer B  in  contact with cathode)
showed an accumulation  of  the  metal  species,  whereas the  first  three Layers  A,
B, and C showed metal  removal.   To demonstrate that there could be a
concentration gradient within the last layer for the zinc/cadmium  test,  the
layer was further subdivided  into  two fractions.
     Results of tests  confirm that BSD is effective in moving both zinc and
cadmium ions from the  cake layer in contact with the anode  to the  cake layer
in contact  with the cathode.   For example,  Layer A  shows  a removal of 97.05
percent cadmium and 85.09  percent  zinc.  In  Layer C,  removal of cadmium
                                       75

-------
                         TABLE  17.   PERFORMANCE OF BSD  PROCESS ON ZINC/CADMIUM  SOIL
Layer
Cake Thickness
Gradient (In.)
0 Anode (+)
1
2
3
3.5
4 Cathode (-)
0
1
1
1
0.6
0.4
Zinc Concentration
(mg/kg) dry soil
PH

3.65
3.55
3.64
4.12
7.66-9.2
Zande
0
167
182
207
409
7755
EPA
0
158
167
197
344
7180
Ave
0
163
175
202
377
7468
Percent
Zinc
Removed
100
85.09
83.99
81.52
65.51
-
Cadmium Concentration
(mg/kg) dry soil
Zande
0
29.2
26.0
53.5
207
6187
EPA
0
25
22
51
208
6310
Ave
0
27.1
24.0
52.3
207.5
6249
Percent
Cadmium
Removed
100
97.05
97.39
94.32
77.45
-
Initial Sample Solids %  =  56.73%
Initial Zinc Concentration  =  1093 mg/kg dry soil  (see  Table  7)
Initial Cadmium Concentration  = 920 mg/kg dry soil  (see Table 7)

-------
Layer B
   Anode  (+)


 Layer A


Layer  D


Layer  C

Layer  Bl

Layer  B2
                        Soil in contact with Anode
                      Soil in between Layer  A and C
                      Soil in between  Layer D and Bl
                      Soil  in  between Layer C and B2
                       Soil in contact  with Cathode
         Cathode (-)
Cake after BSD
Process 4" -  4.5
thickness
          Figure 22.  Schematic of Cake  Divided  Sections
                       for Zinc/Cadmium  Test.
                               77

-------
 and zinc was  94.32 and 81.52 percent,  respectively.  Zinc and cadmium  were
 also removed  in  Layer Bl (the layer which was  subdivided).  This confirms  that
 there is a  concentration gradient  in  the layer  in contact with cathode  (B2).
 This analysis indicates that  both  zinc  and cadmium removal occurred  in  more
 than 90 percent of the treated cake.
      In the  remaining 10 percent of cake (Layer B2, 0.4 in.), there was
 accumulation  of zinc  and cadmium due to an increase  in  pH at the surface of
 the cathode.  The  pH of Layer B2 was between 7.7-9.5.  Zinc  salt is soluble at
 pH below 6,  whereas cadmium salts are  soluble  at pH  below 9. Above  pH 9,
 cadmium would exist as Cd (OH)2,  CdC03,  CdOH+, CdOHCl,  which  are insoluble in
 water.   Figure 23  shows  the solubility of cadmium as a  function  of pH.  The
 solubility of zinc was discussed earlier in  the zinc  tests section.  Also, for
 the prepared  zinc/cadmium soil,  we have calculated the percentage  of zinc and
 cadmium and their  forms at  different  pH values,  7,  8, and 9.   Again, as
 described  previously,  the calculation was  performed using the geochemical
 computer code MINTEQA2.  Table  18  shows calculation  for  percent  distribution
 of zinc and cadmium at pH values of 7,   8, and  9.  More detailed analysis  is
 listed in Appendix E.
      Although in the  initial  concentration of both cadmium and zinc  were  0.1
 percent, it was observed that  there was more  cadmium  removal  than zinc.
 Hence,  it appears that zinc has  higher  affinity to the soil  than does  cadmium.
 According to  Benjamin and  Leckie'35 ,  zinc  will  almost  completely displace
 cadmium and compete for the same soil binding sites.   Because of the higher
 binding force of zinc to the  soil,  more cadmium was removed  than zinc.

QUALITY  ASSURANCE OF ANALYTICAL  DATA:  ZINC AND CADMIUM

      As part  of the quality assurance  of analytical  procedures, chemical
 analyses were performed  in  both  U.S.  EPA and Zande Laboratories for  a  set of
 soil samples.   Comparison of  analytical data are given in Tables 20  and 21 for
 zinc and cadmium, respectively.   For  zinc analysis the variations  of data
 between the two  laboratories  ranged from 0.48  to  28.91 percent.  However,  90
 percent  of the data showed  a  variation  of  less  than 20 percent.    It  was found
 that the U.S. EPA  reported  data were generally higher than  Zande results.  For
                                        78

-------
    £-Cd(OH)2
           1
                                ,\,\,
                                                         12   13
Figure 23.  Distribution Of Hydro'lVS'ls Products (x, y) at I = 1 m and 25' in Solutions

        Saturated witb fl-CdfOHJo-  The Heavy Curve is the Total Concentration of
        rarlmiiim  H l^/ .

-------
             TABLE 18.  PERCENT  IONIC DISTRIBUTION  FOR ZnCl, AND
                        CdCl2  AT PH 7, 8, AND  9
                       pH 7
                           pH 8
                        pH 9
Zn+2




85.0 Zn+2
4.9 ZnCl+
8.5 Zn Acetate


74.8 Zn+2
4.3 ZnCl+
4.5 ZnOH
4.0 Zn(OH)2
4.1 ZnOHCl AQ
11.9 Zn+2
7.6 ZnOH
70.6 Zn(OH)2
7.3 ZnOHCl
1.4 Zn Acetate
Cd+2
29.1OT2  ,
 53.5  CdCr
 6.7  CdCl2
 8.2  Cd  Acetate
 2.0  Cd  Acetate  2
28.4Cd+2
52.6 CdCl+
 6.6 CdCl2
  1.7 CdOHCl
 8.3 Cd Acetate
 2.1 Cd Acetate 2
22. Kd+2
45.5  CdCl+
  6.0CdCl2
  1.0 CdOH+
 15.1 CdOHCl
  7.7 Cd  Acetate
  2.2 Cd  Acetate 2
                                     80

-------
                           TABLE  19.  ZINC QA  DATA
                                                Zinc  Concentration (mg/kg)
                                         7/25/89
               8/15/89
02363

02364

02365
02366

02374
1167

1689

1475
1492

1415
1195
1164  (duplicate)
1767
1711  (duplicate)
1527  (no duplicate)
1548
1546  (duplicate)
1419  (no duplicate)
                                81

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                   TABLE 20.   ANALYTICAL DATA FOR ZINC SOIL
Test
No.
521
5Z2
6Z1
6Z2
7ZA
7ZD
7ZC
7ZB
8ZA
8ZD
8ZC
8ZB
9ZA
9ZD
9ZC
9ZB
10ZA
10ZO
10ZC
10ZB
Zinc Concentration,
mq/Kq (DS)
Zande
2135
383
208
1878
180
687
1847
5644
818
1542
2066
3214
118.6
174.7
204.6
6341
1175
1529
1501
1722
U.S. EPA
1870
272
210
2220
198
852
1940
5310
852
1900
2100
2720
155
253
371
4820
1800
2000
2040
2120
Percent^
Variability Between
Zande and U.S. EPA
6.61
16.95
0,48
8.35
4.76
10.72
2.46
3.05
2.08
10.40
0.82
8.32
13.34
18.31
28.91
13.63
21.01
13.35
15.22
10.36
(a)  Percent variability =
                              /"EPA + Zandej
EPA
                                  EPA + Zande
                                        82

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rABL       ANAL   ICAL  DATA  FOR CADMIUM     SOILS
Sample
Zn-Cd Feed (1)
Zn-Cd Feed (2)
1ZCA
1ZCB1
1ZCB2
1ZCC
1ZCD
Cadmium
EPA
866
873
25
208
6310
51
22
(mg/kg)
Zande
976
955
292
"207
6167
535
26

-------
cadmium,  however,  the analytical data reported  from  both laboratories agreed
fairly  well  (Table  21).   The variation of the  results  was  less than 8.3
percent.

QC Data for Zinc  and Cadmium

           The QC  data provided by U.S. EPA for zinc and  cadmium analyses are
given in  Tables  22  and 23,  respectively.   When spiked  at 1  ppm to the standard
solution,  recovery of zinc varied from 97 to 106 (see Table 22). Also,  the
spiking of soil samples  with  zinc resulted  in a recovery of 85 to 103 percent.
These spike  recovery levels  for both  liquid and  solid  samples  along with the
reported  precision  data  (see  duplicate analysis in Table M)  indicate a high
precision and accuracy of zinc  analysis. Similarly,  high precision and
accuracy  data  are reported  for cadmium analysis  (see Table  23).

 INTERNAL AND EXTERNAL  QUALITY ASSURANCE AUDITS

           Three  internal QA  audits were performed by Battelle's  Quality
Assurance  Unit which  is  independent  of the  research groups  that  conducted  this
study.   The  QA Unit examined the Quality Assurance Project  Plan  and observed
whether the  QA/QC requirements are met. The  QA Unit  also examined  the
laboratory record books.  As a part of the audit program,  Zande  Laboratory was
also audited  while  they were performing the  sample analysis. When  deviation
from the  QAPP  was observed,  appropriate  corrective action was taken  and
documented.
     A Technical  System  Review (TSR) or the external audit  was  performed by
PEI Associates,  Inc. under the direction of  U.S. EPA.  No concerns were  noted
in  (a)  pilot  plant  operation and sample acquisition and  (b)  test methods and
analytical procedures:
     (1)  Battelle identified a  problem in obtaining a representative sample
           of the  test soil  contaminated with decane after treatment.   The cake
           (three  inches  in  diameter  and up  to 2  inches thick)  obtained  from
           the  test  cell  has the  consistency  of a thick paste. Dewatering  was
           stratified with the drier material  on the  top.  If the sample  is
           mechanically mixed,  additional  liquid separates,  making  it difficult
           to obtain a representative  sample. Alternatives were  discussed
           including  quartering  the  cake  and taking alternate  quarters,
                                       84

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                          TABLE 22.  ~QC DATA FOR  ZINC
      Sample ID                           Concentration         % Recovery

QC Standard                                   1  ppm               104
QC Standard                                   1  ppm               106
5Z2                                         272  mg/kg
5Z2 (duplicate)                              297  mglkg
5Z2 (material  spike)                                               103
5Z2 (material  spike,  duplicate)                                    101
QC Standard                                   1  ppm                97.3
1ZCB1                                       344  mq/kg
1ZCB1  (duplicate)                         350  mg/kg
1ZCB1 (material  spike)                                          85
1ZCB1 (material spike,  duplicate)                               87
                                    85

-------
                        TABLE  23.  QC DATA FOR CADMIUM
       Sample ID                           Concentration         % Recovery


QC Standard                                    1 ppm                90-4
1ZCB1                                        208 mg/kg
1ZCB1 (duplicate)                            206 mg/kg
1ZCB1 (material spike)                                              98
1ZCB1 (material spike,  duplicate)                                 105
                                    86

-------
          extracting the  entire  cake,  or coring the cake with a  cork  borer.
          The samples  for zinc analysis do not present  the  same  problem
          because  the  soil  can be dried and ground to a uniform  consistency
          with a mortar and pestle.

      (2)  There was a calculation error  in the standards for the GC analysis.
          The concentration of the standards were  listed as ppm,  but  these
          were volume/volume  ppm.   The analytical data  based  on  these
          standards were  also reported as ppm, but the  analytical  data should
          be ppm on  a  weight/weight  basis.  The  concentration of the  standards
          needed to  be converted to nanograms per  microliter  (using the
          density  of decane) ,  and the  analytical data recalculated to obtain a
          weight/weight  relationship.
As a  resolution to the first issue,  it was decided to quartering the  cake
 (thin slice) and  taking alternate quarters for analysis. Extraction  of the
entire cake or a slice was the preferred approach,  but  the  resources  did not

permit doing so.    As for  the second issue, data were recalculated  to  convert
the ppm values from  volume/volume  basis to weight/weight relationship.
                                       87

-------
                                    SECTION  6
                  COMPARISON  OF TECHNICAL PERFORMANCE OF ESD
                         WITH  OTHER IN SITU TECHNOLOGIES

      Based upon the results of this  limited  study,  it is not possible to make
 a direct quantitative comparison of the  ESD  technology  to  other technologies;
 however, a qualitative  comparison is possible. Table 24 summarizes these
 comparisons.

Organics Treatment

      The most likely ESD application for treatment  of organics  is to enhance
 the  recovery  of non-aqueous phase liquids (NAPL) such as solvents  and  fuel
 oils.   Another  possible  application is to  enhance  recovery  of more soluble
 polar  organics.   This application would be more  like the metals treatment.
 ESD  has the potential to reduce  NAPL  concentrations  at  or  near saturation
 levels (approximately 5,000  -50,000 rag/kg)  to below  saturation  (approximately
 100    1,000 mg/kg),  but  most  probably  not  to low  rag/kg or rag/kg levels.  This
 discussion  will  focus  on the potential for  increased  NAPL recovery.

 Pump and Treat

      Conventional technology for NAPL  recovery consists of some form of
 groundwater and/or NAPL pumping  followed by NAPL separation and/or water
 treatment.   This technology typically  can  succeed in controlling groundwater
 and  NAPL flow and decreasing the potential  for off-site migration.  However,
 success in substantially reducing residual  contamination  is limited. One
 limitation of pump-and-treat  is  that  conventional  NAPL  recovery is dependent
 upon gravity drainage to bring the  NAPL  into a recovery well or trench for
 skimming.
      As water tables move up and down  and  vadose zone moisture  levels change,
 the  fraction of the NAPL in  this free floating phase changes.  As  a result,  a

                                        88

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    TABLE 24.   COMPARISON  OF  ELECTRO-ACOUSTICAL  SOIL  DECONTAMINATION  (ESD)  TO  OTHER IN-SITU  TECHNOLOGIES
CD
<£>
Technology


In-Situ  Biodegradation


I norgan i cs  Treatment

  ESD

  Direct current

  Pump and  treat




  In-Situ  vitrification
                                      Status
                             Cost
                    Limitations
                                      Limited  commercial
                                      availability
Bench-scale

Pilot Scale

Commercially  available




Commercially  available
Low-high




Low?

Low?

Low initial cost
but potentially
high life cycle
cost.

High
                                                 Not fully  proven,  limited
                                                 to biodegradable  compounds.
Unproven.

Unproven.

Never ending,  limited to
saturate zone.
                                                                                       Stabilizes metals  in place,
                                                                                       rather than  removing them.
                                                                                                            '•'V

-------
                                           TABLE 24.   (CONTINUED)
Technology
Status
Cost
Limitations
Organic treatment

  ESD'

  Pump and treat




  Soil venting
  Heat enhanced soil
  Steam  injection
Early bench scale

Commercially  available




Commercially  available
Limited commercial
availability

Limited commercial
availability
  RF heating               Pilot scale

  Direct  current heating   Bench/pilot scale

  In-Situ vitrification    Commercially  available
Low?

Low initial cost
but potentially
high life cycle
cost.

Low (without air
treatment)

Moderate (with air
treatment)

Moderate - high
High


Moderate  - high

Moderate  - high

Highest
Unproven

Never ending,  limited to the
saturated zone.
Limited to volatiles  in  the
vadose zone.
Limited to semivolatiles  in
the vadose zone.

Limited field experience.
                                                    Limited field experience.

                                                    Limited field experience

                                                    Very high temperatures  and
                                                    energy cost.

-------
NAPL  recovery system may reduce or even remove the measurable NAPL phase only
to have  it return under different  hydrological  conditions.
     Under  the  new RCRA underground tank  regulations  (CFR 280.64) the minimum
remediation requirements are  "free product removal."  Achievement of this
level  of remediation may be difficult  using conventional pump-and-treat
technology.   ESD coupled with  a conventional  pump-and-treat technology has  the
potential  to  reduce relatively rapidly the  residual  NAPL concentrations to
levels below  those which would result  in  the  free phase NAPL or  "free product"
layer

Soil Venting

     Soil  vent,  soil vacuum extraction, and  in-site  volatilization,  is a
relatively  simple  and widely utilized  technology for removing volatile  organic
compounds  from  the vadose  zone.   If off-gas  treatment is unnecessary,  costs
are  very low; if treatment is  required,  costs are moderate.  Where off- gas
treatment  is  required,  ESD  has the potential  to  be  less expensive than soil
venting  and  in  some cases may  prove to be a  cost-effective pretreatment  prior
to soil  venting.   It is unlikely  that  ESD can achieve  residual  concentrations
as low as  those possible with  soil venting  for  volatiles.

Heat Enhanced Soil Venting

     Some vendors  of soil  venting services have  begun  to  inject  heated air to
accelerate the  process  and  extend treatment to  less  volatile or  semivolatile
organics.   The  cost  of  energy  to heat  the soils  is  moderately high,  dependent
of course  upon  the targeted temperature.   Comparisons  to  ESD  are similar to
those discussed above for soil  venting.
                                       91

-------
Steam Injection

      Injection of steam to treat volatiles  and  some less-volatile compounds
has been  demonstrated on a limited number of sites. Sufficient data  are not
yet available to  fully evaluate its feasibility, however  energy  costs are
high.   Because of the increased heat  capacity of the wet  soils,  more  heat and
therefore, energy  are required  than for other soil  heating  technologies.

Radio  Freauencv  Heating

      Radio frequency  heating  is an emerging technology for  in  situ  soil
heating.   Roy F.  Weston,  the  licensed vendor,  intends  to  couple  it  with soil
venting to achieve accelerated  remediation.   The comparison to ESD  would be
very  similar to  those discussed above.

Direct Current  Heating

     Direct current is being explored  as  a means of soil heating. As for all
technologies  that  require  increased  soil temperature,  more  energy would  be
required than for  ESD.

In-Situ Vitrification

      In-Situ vitrification  (ISV)  is a  commercially  available technology  in
which a direct current is applied to the  soils  to  achieve super heating.  This
results in soils melting to form a vitrified solid. This differs from direct
current heating only  in that  much higher  temperatures  are achieved  and
correspondingly higher  energy costs  are incurred.   ISV is typically applied  to
inorganics;  however,  limited  data suggest  it  is applicable  to a wide range of
organic compounds.  The organics are probably either volatilized  or are
oxidized.   Because of the high cost, ISV will most  likely only be utilized at
very high hazard sites where very  low  cleanup  levels  are required.  ESD alone
would most likely  not be  applicable  to  these sites.
                                       92

-------
 Biodeqradation

      In situ biodegradation  is  a technology that is receiving  widespread
 attention.   It has,  to  date,  been proven effective at a  limited  number of
 sites and for a limited number  of compounds.   The technology is  only
 applicable  to biodegradable organics.   As the technology evolves,  more wide-
 spread application may occur.   At some sites, BSD may prove to be a cost-
 effective  pretreatment prior to  application  of an in situ  biodegradation
 technology.

 MATERIALS TREATMENT

      BSD usage for  removal  of metal ions is  a distinctively different
 application of the  technology  from NAPL organics treatment.   In this
 application, BSD  may or may not be coupled  with a more conventional  pump-and-
 treat technology.    BSD  has  the potential to  substantially  reduce residual
 metals concentrations to or below the low mg/kg or mg/kg  level.  Unlike
 organics treatment,  there are  a relatively  limited number  of technologies  for
 the treatment of  metals  in-situ.

 Direct  Current

      Direct current has been applied to  remove  metals in-situ.  The  Dutch
 Geokinetics process is  a promising technology, utilizing a novel circulating
 fluid electrode to  prevent  metals deposition.  The direct-current technology
 is a part  of  the  BSD technology;  however, by combining  electrical and
 acoustical  fields,  BSD  has  the potential to  improve treatment  efficiency.

Pump  and  Treat

      As discussed  for organics  treatment,  the pump -and-treat technology is
 potentially successful at hydraulically controlling a plume of contaminated
 groundwater  but is  frequently  ineffective at  substantially  reducing  residual
 soil  contamination.    BSD  has  the potential  to  improve  substantially  this
 treatment.
                                        93

-------
In-Situ  Vitrification

      In-situ  vitrification was designed for  and is typically applied  to
inorganic  contaminants.   Direct current  is  applied to heat the soil  to  its
melti ng point and vitrify the contaminated soil into an  impermeable  mass.
This  technology  does  not remove the metals  but rather immobilizes  them  in
situ.  The  technology requires substantially more  energy and funds than  does
BSD.
                                        94

-------
                              SECTION 7

                             CONCLUSIONS
(1) Electro-acoustic  decontamination  of soil in a  laboratory mode was
     proven technically feasible  for  inorganic contaminants.

(2)  Zinc removal/concentration  (80-90 percent) was observed in the
     presence  of the electric field.

(3) There  appears  to  be a combined electric and  acoustics effect during
     zinc removal.   However,  further  testing is required  to  determine
     accurately the magnitude of  the  effect.

(4)  Longer leaching times  yielded higher zinc  removal efficiencies.

(5)  Higher power levels yielded higher zinc removal  rates.

(6)  Cadmium/zinc removal/concentration (90-95  percent) was observed  in
     the presence of the electric  field.

(7) A  large  discrepancy was  observed between U.S.  EPA and Zande Labs
     decane analyses.

(8) Since  a  large  variability  in  analytical determination of decane  in
     the soil  was observed,  no  definitive  conclusions can be  drawn  on the
     effect of electro-acoustics  on decane  removal  from soils.
                                  95

-------
                                    SECTION 8
                                 RECOMMENDATIONS

     Based  on  Phase 1 laboratory experimental results  for decontamination of
heavy metals  in clayed soil,  a study  is  recommended  and should be conducted to
further evaluate the BSD process in field conditions.  Such a  study  would
validate the Phase  I  results and would provide  the  basis for  developing  design
and operational  changes  for successful field  applications.
     We also  recommend  no additional  work on  the  decane contaminated soil
until the  analytical and experimental  problem can be  solved.  The results from
the decane  experiments  were inconclusive because  of  substantial experimental
uncertainty in  the  decane analysis  and also possibly in experimental
procedures.
                                       96

-------
                                    SECTION 9

                                    REFERENCES
1.    1986  Undersround Motor  Fuel  Storage Tanks:  A National  Survey. Vol.  1,
     U.S.  EPA Technical  Report 560/5-86-013, Washington,  D.C., 1986.

 2.   Houy,  G. E. and  M.  C.  Marley,  "Gasoline Residual  Saturation  in Uniform
     Aquifer Materials",  T.  Env.  Enq..  ASCE 112(3):  586-604,  1986.

3.   Casagrande, L. ,   "Electroosmosis and Related  Phenomena", Harvard Soil
     Mechanics  Series No. 66  (1962).

 4.   Casagrande, L. ,   "Review  of Past and Current  Work  in Electroosmotic
     Stabilization of Soils",  Harvard Soil  Mechanics Series  NO.  145 (1957).

 5.   Muralidhara,  H.  S., and  D.  Ensminger,  "Acoustic Dewatering  and Drying:
     State-of-the-Art Review,"  Proceedings IV, International  Drying Technology
     Symposium,  Kyoto, Japan,  1984.

 6.  Muralidhara,  H.  S. ,  and N. Senapati,  "A Novel Method  of Dewatering Fine
     Particle Slurries," presented  at International Fine Particle  Society
     Conference, Orlando, Florida,  1984.

 7.  Muralidhara,  H.  S. ,  et al. ,  Battelle's  Dewatering Process  for Dewatering
     Lignite Slurries, Battelle Phase I  Report to UNO  Energy Research
     Center/EPRI,  1985.

 8.   Chauhan, S. P. ,   H.  S. Muralidhara,  B.  C.  Kim,  "Electroacoustic Dewatering
     of POTW Sludges", Proc.  National Conf.  on Municipal Treatment Plant Sludge
     Management,  Orlando, Florida,  May 28-30,  1986.

 9.  Muralidhara,  H.  S. ,  et al. ,   "A Novel Electro Acoustic Process for
     Separation  of fine  Particle  Suspensions",  Ch. 13, pp. 374,  in Advances  in
     Solid-Liauid  Separation.  Editor H.  S.  Muralidhara.

 10.  Muralidhara,  H.  S. ,  N.  Senapati,  and B. K.  Parekh,  Solid-Liquid Separation
     Process for Fine Particle Suspensions  by  an Electric and Ultrasonic  Field,
     U.S.  Patent 4,561,953,  December 1985.

 11. Senapati,  N. , H. S. Muralidhara  and R.  E. Beard on  "Ultrasonic
     Interactions  in  Electra-acoustic Dewatering",  presented at  British Sugar
     Technical  Conference,  Norwitch, U.K., June 1988.

 12.  Muralidhara,  H.  S. ,  "Recent  Developments   in  Solid-Liquid Separation",
     presented  at  the Trilaterial  Particuology Conference in  Peking,  China,
     September  1988.


                                        97

-------
 13. Beard, R. E.,  and H.  S.  Muralidhara,   "Mechanistic  Considerations of
    Acoustic  Dewatering Techniques",  Proc.  IEEE,  Acoustic  Symposium, pp.  1072-
     1074,  1985.

 14, Muralidhara, H.  S.,  Editor,  Recent  Advances  in So lid-Li au id  Separation.
     Battelle  Press,  Columbus, OH, November  1986.

 15, Hunter, C. J.,  Zeta Potential  in Colloid  Science Principles, and
    Applications.  Academic Press, 1981.

 16, Bell,  T.  G.,  U.S.  Patent No. 2,799,641  (1957)

 17. Paris,  S.  R.,  U.S. Patent No.  3,417,823 (1968).

 18, Gill, W. G.,  U.S. Patent No.  3,642,066  (1972)

 19. Bell,  C.  W.,  and Titus, C.  H.,  U.S.  Patent  No. 3,782,465  (1974).

 20. Kermabon,  A. J.,  U.S.  Patent No. 4,466,484 (1984).

 21. Hardy, R. M.,  Unpublished presentation at NRC Canada,  Ottawa,  Canada  (Dec
     1953).

 22. Banerjee, S.,  "Electrodecontamination  of  Chrome-Contaminated Soils",  Land
    Disposal,  Remedial Action,   Incineration and  Treatment  of Hazardous Wastes
     Proc. Thirteenth  Annual Research Symposium,  pp.  192-201  (July, 1987).

 23 Horng,  J. J., Banerjee,  S., and Hermann,  J.  G.,  "Evaluating
     Electrokinetics  as a Remedial Action Technique",  Second  International
    Conference on New Frontiers for Hazardous Waste Treatment,  Pittsburgh PA
     (Sept. 27-30,  1987).

 24. Anbah, S. A.,  et al.,  "Application  of Electrokinetic  Phenomena  in Civi
    Engineering  and Petroleum Engineering", Annuals, Volume 118, Art.  14,
     (1965).

 25. Lageman,  R.,   "Electro Reclamation  in Theory  and Practice",  presented  at
     Forum on Innovative Hazardous Waste  Treatment  Technologies  at Atlanta,
    Georgia,  June  19-21,  1989.

 26. Hamnett,  R.,   "A Study of the Processes Involved  in the Electro  Reclamation
    of Contaminated  Soils",  Master  of Science  Degree  thesis, submitted to  V.
    Manchester,  U.K.,  October,   1980.

 27, Probstein, R.  F. and P.  C.  Renaud,  "Quantification  of Fluid  and Chemical
     Flow in Electrokinetics", presented  at University of  Washington,  Workshop
    on Electrokinetic Treatment and  its  Application in Environmental
    Geotechnical  Engineering for Hazardous  Waste Site Remediation at Seattle,
    Washington,  August 4-5,  1986.

28. Mitchell,  J. K,   "Potential  Uses  of Electrokinetics for  Hazardous  Waste
    Site Remediation",  presented at Electrokinetic Treatment and  its
    Application in Environmental Geotechnical  Engineering for  Hazardous  Waste
    Site Remediation,  Seattle,  Washington, August  4-5,  1986.

                                        98

-------
29. Kelsh, D. J., and R. H. Sprate,  "Dewatering Fine Particle  Waste
    Suspensions with Direct Current",  Encyclopedia of  fluid  Mechanics,  Chapter
    27, pp.  1171-1188,  1986.

30. Fleureau, J. N. and M.  Dupeyrat,  "Influence of an  Electric  Field  on the
    Interfacial Parameters  of  Water/Oil  Rock System Application to Oil
    Enhanced Recovery",  T.  Colloid and Interface Sci..  123(1), p. 249-258,
    1988.

31. Lockhart, N. C.,  "Electroosmotic  Dewatering of clays III  Influence  of clay
    Type  Exchangeable Cations  and  Electrode Materials", Colloids  and  Surfaces,
    6, 253-269  (1983).

32. Puri, A. N.  and Anand,  B. ,  "Reclamation of Alkali  Soils  by
    Electrodialysis",   Soil  Science.  42,  p.  23-27,  1936.

33.  Blok,  L. , DeBruyn,  P.  L. ,  "The ionic double layer  at  the Zno/Solution
    interface 1.  The  experimental point of zero  charge"  .T.  Coll. Interface.
    Science, 32, p. 518-538, 1970.

34.  Baes,  Charles F. ,  Jr.  and  Robert  E.  Mesmer, "The  Hydrolysis of Cations",
    1986.

35. Rai,  D. , et al.  ,  "Chemical Attenuation Rates,   Coefficients,  and  Constants
    in Leachate, Migration",  report prepared by Battelle  Pacific Northwest
    Laboratories,  for EPRI,  EPRI Project NO. EA-3356,  Vol. I, February 1984
    (P9-5)

36. Beard, R. ,   F. B.  Stulen,  Summary Report for Concept Study  on  Down Hole
    Skin  Removal, A Gas Transmission Company.  June 1985.

37. Armour Research Foundation Technical Report No. 2, by  F.  G.  Tyzzer and H
    C. Hardy,  March  1951, DA-44-009 Eng-106
                                       99

-------
APPENDIX A
DECANE DATA
   100

-------
DECANE TEST  DATA
Initial Decane % as dosed in the
Initial Decane % as dosed in the
Initial Solids % as dosed in the
Test
Test
1
10D*

UD*

12D*

13D*
Time
Hr
1.25

1.25

1.25

1.75
Voltage
volts/in.
37.5

25.0

12.5

25.0
lab = 8.0 (D.B.)
lab = 4.21 (W.B.)
lab = 52.68
Acoustic
Current
Amp
0.18

0.16

0.08

0.19
Power
Watts
0

0

0

0
Final
BSD
Treated Soil Analysis
Cake EPA Decane
Zande
Decane
Solids % % (W.B. ) %(D.B.) %(W.B.) %(D.B.)
68.52
-------
                                                   DECANE TEST DATA
                                                      (Continued)
Initial Decane  % as dosed in the  lab  =  7.97 (D.B.)
Initial Decane  % as dosed in the  lab  =  4.20 (W.B.)
Initial Solids  % as dosed in the  lab =  52.68
     Test
Test Time    Voltage
  I    Hr     volts/in.
                                                     ESP Treated  Soil  Analysis
        Acoustic   Final
Current    Power    Cake      	   	
  Amp      Watts    Solids  % %(W.B.)  %(D.B.)   %  (W.B. )%(D.B.)
                                                  EPA Decane
                                Zande Decane
                                                                                     Comments
14D*    1.25
        25.0
15D*
1.25     0
20D*  24.0   5.0
21D*   24.0      S.(
 0.15
 17D*  2.0       12.5       0.08

 18D*   141.5   6.25-41.25    0.008
                  0.009
                              0
66.30
                                                   (a)
3.170   4.78
                    53.73
                                                   (a)
            3.480     6.476
                    64
                                                .5
-------
                                                  DECANE TEST DATA
                                                      (Continued)
Initial Decane % as  dosed  in  the  lab
Initial Decane % as  dosed  in  the  lab
Initial Solids % as  dosed  in  the  lab
                                        7.97 (D.B.)
                                        4.20 (W.B.)
                                        52.68
                                                          ESP  Treated  Soil  Analysis
    Test'                      Acoustic  Final
Test  Time   Voltage     Current    Power    Cake         EPA Decane      	
  #    Hr    volts/in.   Amp     Watts    Solids  % %(W.B.)  %(D.B.)    %(W.B.)  %(D.B.)   Comments
                                                                           Zande Decane
22D*
        1.25
1 watt     54.7(a)
400 Hz
                            2.890   5.28
 3.6900  6.75
Sample was mixed  for
analysis.
23D*
        1.25
26DA*    2.0
26DA1*  2.0      37.5

26DA2*  2.0      37.5

26DB*    2.0     37.5
0    0.47 watts  55.3^
     400 Hz
                  37.5     0.13
         0
                 73.67
                      ^
                      3.4400   6.22


                     3.96      5.38
                                                       3.90

                                                       4.45

                                                       4.3
                              5.29

                              6.040

                              6.07
                                                                           3.6400   6.58
                                                                           6.71     9.11
6.55     8.89

5.82     7.91

5.95     8.40
                 Sample was mixed  for
                 analysis.

                 Cake was divided  into
                 three  sections.  Section
                 A -  closer to the anode.
                 Section  B  -  between
                 Section  A & C. Each
                 section  is 0.5  in
                 thickness. Total  cake
                 thickness 2.5  in.
                 No  mixing.

-------
                                                  DECANE TEST DATA
                                                     (Continued)
Initial Decane % as dosed  in the  lab  =  7.97  (D.B.)
Initial Decane % as dosed  in the  lab  =  4.20  (W.B.)
Initial Solids % as dosed  in the  lab  =  52.68
      Test1
Test'  Time   Voltage
  #    Hr    volts/in.
       Acoustic  Final
Current   Power    Cake
  Amp     Watts    Solids
      ESP Treated Soil Analysis
    EPA  Decane
Zande Decane
% %(W.B.) %(D.B.)   %(W.B.)  %(D.B.)    Comments
26DC*
27DA*
2.0
2.0
37
45
.5
.0
0.11 0 72.65^
3
4
.9
.35
6
5
.29
.987
5.
6.
53
47
8.9
8.91
27DB* 2.0       45.0

27DC* 2.0       45.0

28DA* 2.0       25.0
                           0.10
                   61.24a     4.17    6.809

                   50.58^a^    3.56    7.038

                   70.35(a)    4.29    6.098
                     5.21

                     5.89

                     5.93
                     7.25
       8.51

      11.64

       9.37
                                                                                          Cake was divided  into
                                                                                           three sections',  Section
                                                                                           A - closer to the anode.
                                                                                           Section B - between
                                                                                           Section A &  C.  Each
                                                                                           section is 0.5 in
                                                                                           thickness. Total cake
                                                                                           thickness  2.5 in.
Cake was divided  into
three sections. Section
A -  closer to the anode.
Section B - between
Section A & C.  Each
section is 0.5  in
thickness. Total cake
thickness  2.5 in.

-------
                                                  DECAWE TEST DATA
                                                     (Continued)
Initial Decane % as dosed in the lab = 7.97 (D.B. )
Initial Decane % as dosed in the lab = 4.20 (W.B. )
Initial Solids % as dosed in the lab = 52.68
Test'
Test' Time
# Hr
28DB* 2.0
28DC* 2.0
SODA* 2.0'
Voltage
volts/in.
25.0
25.0
37.5
Acoustic
Current ' Power
Amp Watts
0
0
0.11 0.697
400 Hz
Final BSD Treated
Cake EPA Decane
Solids % %(W.B.) %(D.B.)
65.60^ 4.07 6.204
59.89^a^ 3.34 5.576
73.79^ 4.44 6.017
Soil Analysis
Zande Decane
%(W.B.) %(D.B.) Cements
4 . 98 7.6
6.28 10.49
6.10 8.27 Cake was divided into
three sections. Section
                                                                                           A -  closer to the anode.
                                                                                           Section B  -  between
                                                                                           Section A & C. Each
                                                                                           section is  0.5  in
                                                                                           thickness.  Total  cake
                                                                                           thickness 2.5  in.
30DB*

30DC*

2.0

2.0

37.5

37.5

0.697 68.01W
400 Hz
0.697 61.40^
400 Hz
3.90

3.54

5.13

5.77

5.94

5.13

8.73

8.36

(a) Final  solids percent reported by Zande.

  Note:'   2 in. cake was used  in test 10D through 23D.
         2 1/2  in cake was used  in 26D through  300.

-------
APPENDIX  B



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-------
       APPENDIX C

GEOCHEMICAL  CALCULATIONS
      FOR ZINC SOIL
          110

-------
                               Zinc at pH 6 (pg
   PC  VERSION: MINTEQA2   DATE OF CALCULATIONS: 08/24/89      TIME:  16:38:42
                   Zinc Solubility and Percent Distribution at pH 6
  Temperature (Celsius):  25.OO
  Units of concentration: PPM
  Ionic strength to be computed.
  Carbonate concentration represents carbonate alkalinity.
  Do not automatically terminate if charge imbalance  exceeds  30V.
  Precipitation is allowed only for those solids  specified  as ALLOWED
    in the input file (if any).
  The maximum number of iterations is: 10O
  The method used to compute activity coefficients  is:  Debye-Huckel  equation
  Do not print the full species database including  gram-formula weights and
    Debye-Huckel parameters.
                                            LOG  GUESS   ANAL  TOTAL
                                                -1.820   2.00OE+03
                                                -1.250
                                                -6.OOO
     950  0.200E+04   -1.82
     180  0.200E+04   -1.25
     330  0.101E-04   -6.0O
0 H20 HAS BEEN INSERTED AS A COMPONENT
   3   1
     330     6.0000     O.OOOO
OINPUT DATA BEFORE TYPE MODIFICATIONS
0   ID        NAME       ACTIVITY GUESS
     950  Zn+2                1.514E-O2
     ISO  Cl-1                5.623E-O2
     33O  H+l                 l.OOOE-06
       2  H20                 l.OOOE+OO
0   ID        NAME       ANAL MOL   CALC MOL
   NEW LOCK    DIFF FXN
     95O  Zn+2          2.0OOE+03  O.OOOE+OO 1.514E-O2
    0.0000   O.OOOE+00
     ISO  Cl-1          2.0OOE+03  O.OOOE+00 5.623E-O2
    0.0000   O.OOOE+OO
     330  H+l           1.008E-05  O.OOOE+00 1.OOOE-O6
    6.0000   O.OOOE+00
       2  H2O           O.OOOE+00  O.OOOE+00 l.OOOE+OO
    O.OOOO   O.OOOE+OO
                                                 O.OOO
                                                ACTIVITY
                                                   2.000E+03
                                                   1.OO8E-O5
                                                   O.OOOE+00
                                                     LOG  ACTVTY

                                                     -1.82000

                                                     -1.25OOO

                                                     -6.00000

                                                       0.00000
0
O
CATIONS)
1
   GAMMA

1.000000

1.000000

l.OOOOOO

l.OOOOOO
CHARGE BALANCE: UNSPECIATED
      SUM OF CATIONS= 6.144E-02 SUM OF ANIONS  =  5.664E-02
      PERCENT DIFFERENCE =  4.062E+OO    (ANIONS  -  CATIONS)/(ANIONS
                              111

-------
                                 Zinc at pH 6  (pg 2)
0    SPECIES:   TYPE  III - FIXED SOLIDS
0   ID        NAME       CALC MOL       LOG MOL
       2  H20           -3.352E-05      -4.475
     330  H-t-1            3.353E-05      -4.475
1
                                            NEW LOGK      DH
                                           0.001      0.000
                                           6.00O      0.000
   PC  VERSION: MINTEQA2   DATE OF CALCULATIONS: OB/24/89
                                                     TIME:  16:39:12
  PERCENTAGE DISTRIBUTION OF COMPONENTS AMONG
species
                                              dissolved and  adsorbed
+C1-1
+H20
•M-H-1
        94.0     PERCENT BOUND IN SPECIES #    950   Zn+2

                 PERCENT BOUND IN SPECIES 4*9501800   ZnCl



                 PERCENT BOUND IN SPECIES #    180   Cl-1

                 PERCENT BOUND IN SPECIES #9501800   ZnCl



        48.9     PERCENT BOUND IN SPECIES #9501804   ZnOHCl AQ

        5O.1     PERCENT BOUND IN SPECIES #9503300   ZnOH



        48.9     PERCENT BOUND IN SPECIES #9501804   ZnOHCl AQ

                 PERCENT BOUND IN SPECIES #9503300   ZnOH
 IDX
NAME
                            EQUILIBRATED MASS DISTRIBUTION
  DISSOLVED
MOL/KG   PERCENT
   SORBED
MOL/KG   PERCENT
 PRECIPITATED
MOL/KG   PERCENT
950
ISO
2
33O
Zn+2
Cl-1
H20
H+l
3.
5.
3.
-3.
072E-02
664E-02
352E-05
352E-05
1OO
10O
100
100
.0
.O
.0
.0
0.
0.
0.
O.
OOOE+00
OOOE-t-OO
OOOE+OO
OOOE+00
O.O
0.0
0.0
0.0
0
O
0
0
.OOOE+OO
.OOOE+OO
.OOOE+00
.OOOE+00
0.0
0.0
0.0
0.0
     CHARGE BALANCE: SPECIATED
           SUM OF CATIONS
                    5.951E-O2 SUM OF ANIONS   5.475E-02
                                 112

-------
                                Zinc at pH 6 (pg 3)
O          PERCENT DIFFERENCE =   4.168E+OO
CATIONS)
O     NONCARBONATE ALKALINITY =   1.298E-O8
0 IONIC STRENGTH = :  8.6O1E-02
1
   PC  VERSION:  MINTEOA2   DATE OF CALCULATIONS: 08/24/89
                      (ANIDNS - CATIONS)/(ANIONS
                                                              TIME: 16:39:13
©Saturation indices and
O    ID *     NAME
each component
   4195OOO 2NCL2
   2O950OO ZN(OH)2 (A)
   2095001 ZN(OH)2 (C)
   2095OO2 ZN(OH)2 (B)
   2095003 ZN(OH)2 (G)
   2095004 ZN(OH)2 (E)
   4195001 ZN2(OH)3CL
l.OOO)18O
   4195002 ZN5(OH)8CL2
2.0OO)180
   2095005 ZNO(ACTIVE)
   2095O06 ZINCITE
stoichiometry of all minerals
Sat. Index        Stoichiometry  in parentheses) of
  11.702
  -2.37O
  -2.120
  -1.670
  -1.630
  -1.420
  -2.417

  -2.854

  -1.230
  -1.060
( 1.000)950 (
( -2.000)330 (
( -2. OOO) 330 (
( -2.000)330 (
( -2. OOO) 330 (
( -2.000)330 (
( -3.000)330 (
( -8.000)330 (
( -2.000)330 '(
( -2.000)330 (
2.000)180
1.0OO)95O
1.000)950
1.000)950
1.000)950
1.0OO)95O
2.OOOJ95O
5.000)950
1.000)950
1.0OO)95O

( 2.000)
( 2.000)
( 2.000)
( 2.000)
( 2. OOO)
( 3 . OOO )
( 8.000)
( 1.000)
( l.OOO)

2
2
2
2
2
2
2
2
2
                                    113

-------
                               Zinc at pH 9.7 (py I)
   PC  VERSION: MINTEOA2   DATE OF  CALCULATIONS:  08/24/89     TIME:  16:48:04
                    Zinc Solubility and Percent Distribution at pH 9.7
  Temperature (Celsius):  25.OO
  Units of concentration: PPM
  Ionic strength to be computed.
  Carbonate concentration represents  carbonate alkalinity.
  Do not automatically terminate  if charge  imbalance exceeds 3O"/.
  Precipitation is allowed only for those solids specified as ALLOWED
    in the input file (if any).
  The maximum number of iterations is:  1OO
  The method used to compute activity coefficients is: Debye-Huckel equation
  Do not print the full species database including gram—formula weights and
    Debye-Huckel parameters.
ct
95O
180
500
330
          0.20OE+O4
          0.218E+O4
          0.100E+03
          0.101E-04
-1.82
-1.25
-2.40
-9.7O
O H20 HAS BEEN  INSERTED  AS A COMPONENT
   1   1
     33O     9.7OOO      O.OOOO
OINPUT DATA BEFORE TYPE  MODIFICATIONS
ID NAME
950 Zn-t-2
180 Cl-1
5OO Na+1
33O H+l
2 H20
I D NAME
NEW LOCK DIFF FXN
950 Zn+2
O.OOOO O.OOOE+OO
180 Cl-1
O.OOOO O.OOOE+OO
5OO Na+1
O.OOOO O.OOOE+OO
33O H+l
9.70OO O.OOOE+OO
2 H20
O.OOOO O.OOOE+OO
ACTIVITY
1.5.
5.6:
3.9(
1.9<
1.0<
ANAL MOL

2.0OOE+O3

2.18l!f.+03

1.0OOf-:+O2

"i.oorat --O5

o.ooo;-.+oo

5UESS LOG GUESS ANAL TOTAL
»E-02
XE-02
LE-03
5E-10
3E+00
CALC MOL
O.OOOE+OO
O.OOOE+OO
O.OOOE-t-OO
O.OOOE-t-OO
O.OOOE+OO
-1.820
-1.25O
-2.40O
-9.700
0.000
ACTIVITY
1.514E-02
5.623E-02
3.981E-03
1.995E-10
i.OOOE+OO
2.00OE+03
2.181E+03
l.OOOE+02
1.008E-05
O.OOOE-t-OO
LOG ACTVTY
-1.82000
-1.25OOO
-2.40OOO
-9.70000
O.OOOOO
                                                                           GAMMA

                                                                        l.OOOOOO

                                                                        l.OOOOOO

                                                                        l.OOOOOO

                                                                        l.OOOOOO

                                                                        l.OOOOOO
     CHARGE  BALANCE:  UNSPECIATED
                                    114

-------
                           Zinc at pH 9.7  (pg 2)
 9501802  ZnC13 -
0.602      9.56O
 95O18O3  ZnC14 -2
0.582     1O.96O
 95O330O  ZnOH +
-8.86O     13.399
 9503301  Zn(OH)2 AQ
-16.906      O.OOO
 9503302  Zn(OH)3 -
-28.299      O.OOO
 95O3303  Zn(OH)4 -2
-4O.80O      0.000

0    SPECIES:   TYPE
0   ID        NAME
       2  H20
        1.143E-10  O.OOOOOOO   -10.04407    0.790735

        5.251E-12  O.OOOOOOO   -11.66251    O.414223

        2.986E-O5  O.OOO0237    -4.62477    O.794654

        2.269E-O2  O.O230788    -1.63679    1.017O06

        7.763E-O3  O.OO61687    -2.20980    O.794654

        2.O72E-04  O.OOOO826    -4.08282    O.398760
     III  - FIXED SOLIDS
        CALC MOL       LOG MOL      NEW LOGK      DH
                       -1.151
0.001
                     -7.O65E-02


PC  VERSION: MINTEQA2   DATE OF CALCULATIONS: 08/24/89
0.000
                                                              TIME:  16:48:38
  PERCENTAGE DISTRIBUTION OF COMPONENTS AMONG
species
                                      dissolved and adsorbed
+C1-1
-i-Na+1
+H+1
73.9     PERCENT BOUND IN SPECIES #9503301   Zn(OH)2 AO

         PERCENT BOUND IN SPECIES #9503302   Zn(OH)3



99.9     PERCENT BOUND IN SPECIES *    180   Cl-i
                100.0
         PERCENT BOUND IN SPECIES #    50O   Na+1
                855.1     PERCENT  BOUND  IN  SPECIES  H95O18O4    ZnOHCl  AQ

               >1OOO.     PERCENT  BOUND  IN  SPECIES  K330OO20    OH-

                752.6     PERCENT  BOUND  IN  SPECIES  K95O33OO    ZnOH +

               >1000.     PERCENT  BOUND  IN  SPECIES  K95O33O1    Zn(OH)2 AQ

               >1000.     PERCENT  BOUND  IN  SPECIES  #9503302    Zn(OH)3

               >10OO.     PERCENT  BOUNO  IN  SPECIES  #9503303    Zn(OH)4 -2
                                    115

-------
+H2O
                            Zinc at pH 9.7 (pg 3)


                  1.5     PERCENT BOUND IN SPECIES #33OOO20   OH-

                 64.2     PERCENT BOUND IN SPECIES #9503301   Zn(OH)2 AQ

                          PERCENT BOUND IN SPECIES #9503302   Zn(OH)3

                          PERCENT BOUND IN SPECIES #9503303   Zn(OH)4 -2
                            EQUILIBRATED MASS DISTRIBUTION 	
 IDX
         NAME
  DISSOLVED
MOL/KG   PERCENT
 95O  Zn+2
 ISO  Cl-1
 5OO  Na+1
 330  H+l
   2  H2O
3.073E-02
6.178E-02
4.368E-03
-3.967E-06
7.065E-02
10O.O
100.0
10O.O
1OO.O
1OO.O
O.OOOE-t-00
O.OOOE+OO
O.OOOE+OO
O.OOOE-i-OO
O.OOOE-i-OO
   SORBED
MOL/KG   PERCENT
                                                        0.0
                                                        0.0
                                                        0.0
                                                        0.0
                                                        O.O
                                                                PRECIPITATED
                                                               MOL/KG   PERCENT
                                      O.OOOE+OO
                                      O.OOOE+OO
                                      O.OOOE+00
                                      O.OOOE+OO
                                      O.OOOE+OO
                                0.0
                                0.0
                                O.O
                                0.0
                                0.0
     CHARGE BALANCE: SPECIATED
           SUM OF CATIONS =  7.5O4E-O2 SUM OF ANIONS
0
O
CATIONS)
0     NONCARBONATE ALKALINITY =
0 IONIC STRENGTH = :  7.324E-02
1
                                7.10OE-02
           PERCENT DIFFERENCE =   2.767E+OO    (ANIONS - CATIONS) / (ANIONS •*•

                                  1.082E-O3
   PC  VERSION: MINTEQA2   DATE OF CALCULATIONS: 08/24/89
                                                               TIME:  16:48:38
OSaturation indices and
0    ID #     NAME
each component
   415000O HALITE
   4195000 ZNCL2
   20950OO ZN(OH)2
   2095OO1 ZN(OH)2  (C)
   2095002 ZN(OH)2
   2095OO3 ZN(OH)2
   2095OO4 ZN(OH)2
   4195O01 ZN2(OH)3CL
l.OOO)18O
   41950O2 ZN5(OH)8CL2
2.OOO)180
   20950O5 ZNO(ACTIVE)
   2O95O06 ZINCITE
                        stoichiometry of all  minerals
                        Sat.  Index         Stoichiometry (in  parentheses)  of
                                                                    2.000)   2
                                                                    2.OOO)   2
                                                                    2.000)   2
                                                                    2.000)   2
                                                                    2.OOO)   2
                                                                    3.OOO)   2

                                                                    8.OOO)   2

                                                                    l.OOO)   2
                                                                    1.000)   2


(A)
(C)
(B)
(G)
(E)
CL
CL2
VE)

-5.356
-16.257
2.812
3.062
3.512
3.552
3.762
3.08O
13.322
3.953
4.123
( 1.0OO)5OO (
( l.OOO) 950 (
( -2.000)330 1
( -2.000)330 |
( -2.000)330 |
( -2.OOOJ33O I
( -2.000)330 1
( -3.000)330 1
( -8.0OO)33O 1
( -2.000)330 I
( -2.000)330 1
; i.ooo) iBo
; 2.000)180
; 1.000)950
; 1.000)950
; l.OOO)95O
[ 1.000)950
[ 1.0OO)95O
[ 2.0OO)95O
; 5.000)950
[ l.OOO) 950
[ 1.000)950
                                     116

-------
   APPENDIX D



ZINC/CADMIUM DATA
      117

-------
                                                                ZINC/CADMIUM   ESD    TEST


Tot


1
1 IC-I
1 IC-I
1 IC-C
1 U-ll
1 IC-12


Ilituet
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lleetrriei
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l.S
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llK
-------
       APPENDIX  E

GEOCHEMICAL CALCULATION
 FOR ZINC CADMIUM SOIL
         119

-------
                         Zinc  and Cadmium at pH 7 (pg 1)
 C'C  VERSION:  MINTEOA2   DATE OF CALCULATIONS: 08/22/8?      TIME:  13:12:44


      Zinc and Cadmium Solubility and Percent Distribution with Acetate at pH  7
Temperature  (Celsius):   25.CO
Units o.f concentration:  PPM
Ionic strength  to  be computed.
Carbonate concentration  represents carbonate Alkalinity.
Do not automatical Iv terminate .if  charge imbalance exceeds  30/C
Precipitation is allowed only  for  those solids specified as  ALLOWED
  in the input  file  (if  any).     ~
The maximum  number of  iterations  is:  100
The method used to compute  activity coefficients is: Debye-Huckel  equation
Do not print the full  species  database including gram-f or.r.ula weights and
  Debye-Huckel  parameters.
   950  0.iOOE+Od    -1.32
   160  0.10OE+04    -2.05
   180  0.200E+04    -1.25
   992  0.1OOE+O4    -1.77
   500  0.335E-I-03    -1. 73
   330  0.101E-04    -7.00
H2O HAS BEEN  INSERTED AS A COMPONENT
 3   1
   330     7.OOOO     0.OOOO
INPUT DATA BEFORE TYPE MODIFICATIONS
ID NAME ACTIVITY GUESS LOG GUESS ANAL TOTAL








MEi

0

0

0

0

0
950
160
ISO
792.
500
330
2
ID
K/LOGK
95O
.0000
160
.0000
ISO
.Oooo
99Z
.OOOO
500
.0000
Zn+2.
Cd+2
Cl-l
Acetate
NA^i
H+l
H2Q
NAME
DIFF FXN
lrv-2
O.OOQE+00
Cd+2
O.OOQE+00
Cl-l
O.OOOE+00
Oc@ta.te
o. OQQE-'-OO
fxfa-i-i
0 • 000- *OO
1.514E-02
8.913E-03
5 . 623E— 02
1 . 67SE-02
1 . oiOE-02
1 . OOOE-O7
1 . OOOE+-00
ANAL MOL CALC MOL

1.000E+O3 O.OOOE-^-OO

l.OOO£-*-03 O.OO\)E+00

2. OOOE+03 O.OOOE+OO

l.OOOE+03 C.OOOE+OO

3.650E+O2 O.OOOE+OO

-1.320
-1.050
-1.25O
-1.770
-1.730
-7.000
0.000
ACTIVITY

1.514E-02

S.913E-03

5. 623E-02

1 . 693E-O2

1 . 660E-02.

l.OOOE-t-03
1 .OOOE+03
2 . OOOE+03
1 . OOOE+O3
3.350E*O2
1.00SE-O5
O.OOOE-t-OO
LOG ACTVTY

-1.S20OO

-2.050OO

-1.25000

-1.77000

-1.73000








GAM^A

1 . CX3QOOO

1. OOOOOO

1 . OOOOOO

l.OOOCOO

1 . OOOOOO

                                       120

-------
                           Zinc and Cadmium at pH 7 (pg 2)
 9509921  ZN ACETATE
    0. OOO
 9509922  ZN ACETATE2
    0.000
 9509923  ZNACETATE3
    0.000
        1.310E-03  0.0010387

        7.302E-05  O.OOO0743

        4.430E-O7  O.OOOOO04
0   • SPECIES:   TYPE  III - FIXED SOLIDS
O   ID        NAME       CALC MQL       LOG MOL
       2  H20           -1.796E-O4      -3.746
     330  H+i            1.155E-04      -3.938
-2.98352    0.792691

-4.12899    1.017559

-6.45447    0.792691
                                    NEW LOCK      DH
                                   O.OO1       O.OOO
                                   7.OOO       0.OOO
             1.311

             2.002

             1.731
   PC  VERSION: MINTEQA2   DATE OF CALCULATIONS: 08/22/89
                                              TIME:  13:13:18
  PERCENTAGE DISTRIBUTION OF COMPONENTS AMONG
species
                                      dissolved  and  adsorbed
+Cd+2
+C1-1
••-Acetate
85.0     PERCENT BOUND  IN SPECIES #    95O

 4.9     PERCENT BOUND  IN SPECIES #95O180O    ZnCl  +

 8.5     PERCENT BOUND  IN SPECIES #9509921    ZN ACETATE



29.1     PERCENT BOUND  IN SPECIES #    160

53.5     PERCENT BOUND  IN SPECIES #16O180O    CdCl  +

 6.7     PERCENT BOUND  IN SPECIES #1601801    CdC12 AQ

 8.2     PERCENT BOUND  IN SPECIES #1609921    CD ACETATE

 2.0     PERCENT BOUND  IN SPECIES #1609922    CdACETATE2



87.8     PERCENT BOUND  IN SPECIES #    18O    Cl-1

 1.3     PERCENT BOUND  IN SPECIES #95O18OO    ZnCl  +•

 8.4     PERCENT BOUND  IN SPECIES #16O18OO    CdCl  +

 2.1     PERCENT BOUND  IN SPECIES #16O18O1    CdC12 AQ
                 84.0
         PERCENT BOUND  IN SPECIES #
       992
Acetate
                                        121

-------
                          Z1nc and Cadmium at pH 7 (pg 3)
   PC  VERSION: MINTEQA2   DATE OF CALCULATIONS: 08/22/89
                                      TIME: 13sl3:19
OSaturation indices and
0    ID *     NAME
component
   4150OOO HALITE
   4195000 ZNCL2
   2W50OO ZN(OH)2 (A)
   2095001 ZN(OH)2 (C)
   20950O2 ZN(OH)2 (B)
   2095003 ZN(OH)2 (G)
   20950O4 ZN(OH)2 (E)
   4195001 ZN2(OH)3CL
1.000)180
   4195002 ZN5(OH)8CL2
2.000)180
   2095005 ZNO(ACTIVE)
   2095006 ZINCITE
   4116OOO CDCL2
   4116O01 CDCL2, 1H20
   4116002 CDCL2.2.5H20
   2016000 CD(OH)2 (A)
   2016001 CD(OH)2 (C)
   4116003 CDOHCL
1.000)180
   2016002 MONTEPONITE
stoichiometry of all minerals
Sat. Index        Stoichiometry (in parentheses) of each
-4.868
-12.103
-0 . 700
-O.450
0 . 000 "
0 . 040
0.250
-O .111
3.428
0.441
0.611
-5.133
-4.104
-3.875
-2 . 720
-2.640
-0 . 922
( 1 . OOO ) 50O (
( 1.000)950 (
( -2.000)330 (
( -2.000)330 (
( -2.000)330 (
( -2.000)330 (
( -2.000)330 (
( -3.000)330 (
( -8.000)330 (
( -2.000)330 (
( -2.000)330 (
( 1. OOO) 160 (
( 1.000)160 (
( 1.000)160 (
( -2.000)330 (
( -2 . 000 ) 33O (
( -1.000)330 (
i.ooo)iao
2.000)180
1.000)950 1
1.000)950 I
1.000)950 1
i.OOO)95O 1
1.000)950 I
2.000)950 1
5.0OO)95O 1
1. OOO) 9 50 1
i.OOO)95O 1
2.000)180
2. OOO) ISO I
2.000)180 1
1.000)160 i
1.000)160 1
1.000)160 i


[ 2 . OOO )
[ 2.000)
[ 2 . OOO )
[ 2.000)
[ 2 . OOO )
[ 3.000)
[ 8 . 000 )
[ 1 . OOO )
( 1 . OOO )

[ 1 . 000 )
[ 2 . 50O )
( 2. . 000 )
[ 2 . OOO )
( 1 . OOO )


2
2
2
2
^
2
2
2
2

2
2
2
2
2
  -4.109
(  -2.000)330  (   1.0OO)16O  (  l.OOO)  2
                                       122

-------
                      Zinc and Cadmium at pH 8  (pg 1)
    PC   VERSION:  MINTEQA2   DATE OF CALCULATIONS: 08/22/89      TIME:
 11:43:35


     Zinc and Cadmium Solubility and Percent Distribution with Acetate at pH 8
  Temperature (Celsius):   25.OO
  Units  of  concentration:  PPM
  Ionic  strength to be computed.
  Carbonate concentration  represents carbonate alkalinity.
  Do not automatically terminate if charge imbalance exceeds 30V.
  Precipitation  is allowed only for those solids specified as ALLOWED
    in the  input file (if  any).
  The maximum number of iterations is: 100
  The method  used to compute activity coefficients is: Debye-Huckel
equation
  Do not print the full species database including gram-formula weights  and
    Debye-Huckel parameters.
     950
     160
     180
     992
     50O
     330
O H20 HAS
   3   1
     330
0INPUT
    ,10OE+04
    . 100E+04
    ,200E+04
    .10OE+04
    , 38SE+03
   0.101E-04
-1
__*•>
-1
-1
-1
-a
  ,82
  .05
  ,25
  .77
  ,78
  .00
   BEEN INSERTED AS A COMPONENT
0   ID
     95O
     16O
     ISO
     992
     5OO
     330
       •2.
O   ID
GAMMA
     950
1.000000
     160
1.OOOOOO
      8.0000
DATA BEFCRE TYPE
       NAME
   Zn+2
   Cd+2
   Cl-1
   Acetate
   Na + 1
   H-t-1
   H20
       NAME
   NEW LOCK
   Zn+2
       O.OOOO
   Cd-i-2
       0.OOOO
                     LOG GUESS    ANAL  TOTAL
  o.oooo
  MODIFICATIONS
   ACTIVITY GUESS
        1.514E-02
        8.913E-03
        5.623E-02
        1.698E-O2
        1.660E-02
        1.OOOE-OO
        1.WOE+OO
   ANAL MOL   CALC MOL
DIFF FXN
  1.0OOE+O3  O.OOOE+00  1.514E-02
 O.OOOE+00
  l.OOOE-t-03  O.OOOE+00  8.913E-03
 O.OOOE*OO
1.820
2.050
1.250
1.770
•1.780
•B.OOO
O . OOO
i.OOOE+03
1 . OOOE+03
2.0OOE+03
1 . OOOE+03
3.8SOE-t-02
1.O08E-05
0 . OOOE-KDO
                         ACTIVITY    LOG ACTVTY
                                     -1.8200O
                                       . 05OOO
                                    123

-------
                       Z1nc and Cadmium at pH 8 (pg 2)
  1609922
3.143
  1609923
2.269
  16O9924
2.438
  9509921
1.309
  9509922
2.003
  95O9923
1.729
CdACETATE2
 0. OOO
CdACETATE3
 0. OOO
CdACETATE4
 0. OOO
ZN ACETATE
 0.000
ZN ACETATE2
 0.000
ZNACETATE3
 0. OOO
0    SPECIES:   TYPE
0   ID        NAME
       2  H20
     330  H+l
II
   1.B77E-04  O.OOO19O9

   2.895E-07  O.OOOO002

   4.914E-O9  O.OOOOOOO

   1.182E-03  0.0009403

   6.723E-05  0.0000684

   4 . 1 28E-O7  O . OOOOOO3
              I - FIXED SOLIDS
               CALC MOL       LOG MOL
              -2.730E-03      -2.564
               2.724E-03      -2.565
-3.71925

-6.63772

-8.70620

-3.02674

-4.16522

-6.48369
1.016802

0.795396

0.40O251

O.795396

1.016802

O.795396
                               NEW LOGK      DH
                              O.OO1      O.OOO
                              8.OOO      0.OOO
   PC  VERSION: MINTEQA2
11:44:08
                 DATE OF CALCULATIONS: 08/22/89
                                        TIME:
  PERCENTAGE DISTRIBUTION OF COMPONENTS AMONG
adsorbed species
                                             dissolved  and
-»-Cd+2
       74.8     PERCENT BOUND IN SPECIES #    950    Zn+2

                PERCENT BOUND IN SPECIES #95018OO    ZnCl  +•

        4.5     PERCENT BOUND IN SPECIES #95033OO    ZnOH  +

        4.0     PERCENT BOUND IN SPECIES #9503301    Zn(OH)2 AQ

        4.1     PERCENT BOUND IN SPECIES #9501804    ZnOHCl AQ

        7.7     PERCENT BOUND IN SPECIES #9509921    ZN ACETATE



       28.4     PERCENT BOUND IN SPECIES #    16O    Cd+2

       52.A     PERCENT BOUND IN SPECIES #16018OO    CdCl  +

        6.6     PERCENT BOUND IN SPECIES #16O18O1    CdC12 AQ

        1.7     PERCENT BOUND IN SPECIES #1601803    CdOHCl AQ

        8.3     PERCENT BOUND IN SPECIES #1609921    CD ACETATE

                PERCENT BOUND IN SPECIES #1609922    CdACETATE2
                                      124

-------
                           Z1nc and Cadmium at pH 8 (pg 3)
o
     CHARGE BALANCE: SPECIATED
           SUM OF CATIONS =   5.282E-02 SUM  OF  ANIONS
0
0          PERCENT DIFFERENCE =
CATIONS)
O     NONCARBONATE ALKALINITY =
0 IONIC STRENGTH = :  7.236E-02
1
6.380E-02
                                  9.417E+00    (ANIONS  -  CATIONS)/(ANIONS
                                   1.277E-06
   PC  VERSION: MINTEQA2   DATE OF CALCULATIONS: O8/22/89
                                                              TIME: 11:44:09
OSaturation indices and
O    ID *     NAME
component
   415OOOO HALITE
   4193000 ZNCL2
   2095OOO ZN(OH)2 (A)
   2095001 ZN(OH)2 (C)
   2095OO2 ZN(OH)2 (B)
   2095003 ZN(OH)2 (G)
   2095004 ZN(OH)2 (E)
   4195OO1 ZN2(OH)3CL
1.000)180
   4195O02 ZN5(OH)8CL2
2.000)180
   2095005 ZNO(ACTIVE)
   2095006 ZINCITE
   4116000 CDCL2
   41160O1 CDCL2, 1H20
   4116O02 CDCL2,2.5H20
   2016000 CD(OH)2 (A)
   2016O01 CD(OH)2 (C)
   4116003 CDOHCL
1.000)180
   2016002 MONTEPONITE
                        stoichiometry of all minerals
                        Sat.  Index        Stoichiometry
                          -4.869
                         -12.158
                            .250
                            . 3OO
                            ,95O
                            . 990
  in parentheses) of each
                             2OO
                           2.786

                          11.172

                           2.391
                           2.561
                          -5.142
                          -4.113
                          -3.884
                          -0.724
                          -O.644
                           0.072

                          -2.113
( 1 . 000 ) 50O (
( 1.000)950 (
( -2.000)330 (
( -2.000)330 (
( -2.000)330 (
( -2.000)330 (
( -2.000)330 (
( -3.000)330 (
( -8.000)330 (
( -2.000)330 (
( -2.000)330 (
( 1.000)160 (
( 1.000)160 (
( 1.0OO)16O (
( -2.000)330 (
( -2.000)330 (
( -l.OOO)330 (
( -2.000)330 (
1.0OO)18O
2.000)180
1.0OO)95O (
1.000)950 (
1. OOO) 950
1 . OOO ) 950 (
1.0OO)95O
2.000)950 (
5.000)950
1.000)950 (
1.000)950 (
2.0OOU8O
2.000)180
2.000)180
1.000)160
1.000)160
1.000)160
l.OOO)16O


2 . 000 )
2.000)
2 . OOO )
2. OOO)
2 . OOO )
3 . 000 )
8.000)
1 . OOO )
1.000)

1 . 000 )
2 . 500 )
2 . OOO )
2 . 000 )
1 . 000 )
1 . OOO )


'2
2
2
2
2
2
"2
2
2

2
2
2
2
2
2
                                     125

-------
                            Z1nc and Cadmium at pH 9 (pg 1)
   PC  VERSION: MINTEDA2    DATE  OF CALCULATIONS.- 08/22/89
TIMEs 13:iOt06
           Z1nc and Cadmium Solubility and Percent Distribution with Acetate at pH 9
  Temperature  (Celsius):   25.OO
  Units of concentration:  PPM
  Ionic strength  to  be  computed.
  Carbonate concentration  represents carbonate alkalinity.
  Do not automatically  terminate  if  charge imbalance exceeds 30'/.
  Precipitation is allowed only for  those solids specified as ALLOWED
    in the input  file  (if  any).
  The maximum number of iterations is:  100
  The method used to compute  activity coefficients is: Debye-Huckel equation
  Do not print the  full species database including gram-formula Heights and
    Debye-Huckel  parameters.
950
16O
180
992
500
330
0.100E+04
0.100E-«-04
0 . 200E+04
0.100E+04
0.385E+03
0.101E-04
-1.82
-2.05
-1.25
-1.77
-1.78
-9 . OO
0 H20 HAS BEEN  INSERTED AS  A  COMPONENT
   3   1
     330     9.0000     0.OOOO
0INPUT DATA DEFORE TYPE MODIFICATIONS
O ID
950
16O
180
992
500
330
2
0 ID
NEW LOCK
95O
0.0000
160
0 . OOOO
180
0 . OOOO
992
0 . OOOO
500
0 . OOOO
NAME
Zn+2
Cd+2
Cl-1
Acetate
Na-M
H+l
H20
NAME
DIFF FXN
Zn>2
O.OOOE+OO
CcJ>2
0. OOOE +00
Cl-1
0. OOOE+00
Acetate
0. OOOE* 00
NaU
0. OOOE +OO
ACTIVITY GUESS LOG GUESS ANAL TOTAL
1.514E-02
8.913E-03
5 . 623E-02
1 . 690E-O2
1.660E-02
1 . OOOE-^9
1. OOOE +00
ANAL MOL CALC MOL
1 . OOOE + 03 0 . OOOE-* OO
1 . OOOE> O3 O . OOOE+OO
2 . OOOE+03 O . OOOE +OO
1 . OOOE+03 0 . OOOE+OO
3 . 850E+O2 O . OOOE+OO
-1.820
-2.050
-1.250
-1 . 770
-1.780
-9 . 000
U . OOO
ACTIVITY
1.514E-02
8.913E-03
5.623E-02
1 . 698E-O2
1 . 66OE-02
1 . OOOE+03
1 . OOOE+03
2 . OOOE+O3
1 . OOOE+03
3.850E+02
1.008E-05
0 . OOOE+OO
LOG ACTVTY
-1.82OOO
-2.05OOO
-1.250OO
-1.77000
-1.78OOO
                                                                          GAMMA

                                                                       l.OOOOOO

                                                                       l.OOOOOO

                                                                       l.OOOOOO

                                                                       l.OOOOOO

                                                                       1.OOOOOO
                                      126

-------
                           Z1nc and Cadmium at pH 9  (pg 2)
 9509921   IN  ACETATE
    0. OOO
 9509922   ZN  ACETATE2
    0.000
 9509923   ZNACETATE3
    O.OOO
2.208E-04  O.OOO1B03

1.429E-05  0.0000145

9.389E-08  0.0000001
0    SPECIES:    TYPE   III - FIXED SOLIDS
O   ID        NAME       CALC MOL       LOG MOL
       2  H20           -2.561E-02      -1.592
     330  H+1            2.561E-02      -1.592
1
-3.74407

-4.B39BO

-7.11553
0.816306

1.011920

O.B163O6
                            NEW LOOK      DH
                           O.OO1      O.OOO
                           9 . OOO      0. OOO
1.298

2.005

1.718
   PC  VERSION: MINTEQA2   DATE OF CALCULATIONS: 08/22/89
                                     TIME: 13:10:39
  PERCENTAGE DISTRIBUTION OF COMPONENTS AMONG
species
                              dissolved and adsorbed
+ZO+2
11.9 PERCENT
7. A PERCENT
PERCENT
PERCENT
PERCENT
PERCENT
45.5 PERCENT
6.0 PERCENT
1.0 PERCENT
PERCENT
7.7 PERCENT
2.2 PERCENT
BOUND
BOUND
BOUND
BOUND
BOUND
BOUND
BOUND
BOUND
BOUND
BOUND
BOUND
BOUND
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
IN
SPECIES
SPECIES
SPECIES
SPECIES
SPECIES
SPECIES
SPECIES
SPECIES
SPECIES
SPECIES
SPECIES
SPECIES
# 950
#9503300
#9503301
#9501804
#9509921
# 160
#1601800
#1601801
#1603300
#1601803
#1609921
#1609922
Zn+2
ZnOH +
Zn(OH)
ZnOHCl


2 AQ
AQ
ZN ACETATE
Cd+2
CdCl +
CdC12
CdOH +
CdOHCl


AQ

AQ
CD ACETATE
CdACETATE2
•••Cl-i
                 86.3     PERCENT BOUND  IN SPECIES #     1BO    Cl-1

                          PERCENT BOUND  IN SPECIES #9501804    ZnOHCl  AQ
                                   127

-------