United States
Environmental Protection
Agency
Office of
Solid Waste and
Emergency Response
Office of Program
Management and Technology
Washington DC 20460
Superfund
EPA/540/2-88/003
vvEPA
Assessment of
International
Technologies for
Superfund
Applications
September 1988
-------
EPA/540/2-88/003
September 1988
Assessment of International
Technologies for Superfund
Applications
Technology Review and Trip Report Results
by
Thomas J. Nunno
Jennifer A. Hyman
Alliance Technologies Corporation
Bedford MA 01730
Task Manager
Thomas H. Pheiffer
Office of Program Management and Technology
Office of Solid Waste and Emergency Response
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
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Disclaimer
This Final Report was furnished to the Environmental Protection Agency by Alliance
Technologies Corporation, Bedford, Massachusetts 01730, in fulfillment of Contract No.
68-03-3243, Work Assignment No. 2-16. The opinions, findings, and conclusions
expressed are those of the authors and not necessarily those of the Environmental
Protection Agency or the cooperating agencies. Mention of company or product
names is not to be considered as an endorsement by the Environmental Protection
Agency.
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Contents
Figures iv
Tables v
Acknowledgments vi
Introduction 1
General Approach 1
Overview of Site Remediation Programs in Holland, Belgium, and
Federal Republic of Germany 1
Holland (The Netherlands) 1
Belgium 2
The Federal Republic of Germany (West Germany and West Berlin) 2
Summary of Results 3
Soil Washing Equipment Findings 3
High Temperature Slagging Incineration (HTSI) 5
Other Unique Applications of Site Remediation Technologies 5
Conclusions and Recommendations 7
Appendices
A. Research of Electrochemical Treatment of Organohalogens
in Process Wastewater at TNO 9
B. Research on Decontamination of Polluted Soils and
Dredging Sludges in Bioreactor Systems at TNO 11
C. In Situ Biorestoration of Contaminated Soil Research at RIVM 13
D. Heijmans Soil Washing Operation 17
E. In Situ Cadmium Removal and Onsite Treatment by Ion Exchange 19
F. Rotating Biocontactor for Ground Water Pretreatment of Pesticide Contamination 21
G. HWZ Soil Washing Operation 25
H. Heidemij Soil Washing Using Froth Flotation 29
I. High-Temperature Slagging Incineration (HTSI) 33
J. In Situ Vacuum Extraction and Air Stripping of Volatile Organic Compounds 37
K. Harbauer Soil Washing Using Low Frequency Vibration 41
L. Soil Washing Using the Oil CREP System 45
M. Biological Remediation of Soil Using the ECO-PLUS Biosystem 49
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Figures
Number Page
1 The Assessment of international technologies for Superfund
applications program structure 1
A-1 Diagram of the apparatus for electrochemical treatment of
organohalogens 10
A-2 Mole fraction of the phenols during electrolysis of 2 L of
50 ppm PCP solution (10A) 10
C-1 Infiltration, withdrawal and treatment setup proposed by
RIVM for the Asten site 13
C-2 Biodegradation of gasoline measured as CO2-production
(mg C/kg) 14
D-1 Process scheme of the installation of Heijmans Milieutechmek B.V 18
E-1 Cross-section of the infiltration and withdrawal system
installed by TAUW for Cd leaching 20
E-2 Scheme of the TAUW water treatment plant for ion exchange of Cd 20
F-1 Sketch of the TAUW ground water treatment installation near
Utrecht 22
F-2 Loading and efficiency over time of the TAUW rotating
biocontactor installation 23
G-1 HWZ soil treatment scheme 27
H-1 Two diagrams showing the Heidemij method of in situ
steam stripping 30
H-2 An artist's rendering of a typical Cum-Bac installation
by Heidemij 31
1-1 Schematic of HTSI incineration process 34
I-2 Purification action of the molten film in the HTSI combustion
chamber 35
J-1 Vacuum extraction of volatile organics in the vadose zone by HUT 38
J-2 Volatilization of organics in ground water by pulsing with compressed air 39
J-3 Performance and range of an HUT vacuum extraction installation 40
J-4 Soil gas hydrocarbon concentration over time with HUT
in situ vacuum extraction and air stripping 40
K-1 Flow schematic of the Harbauer soil washing installation 42
L-1 The Oil CREP System SSC-20A 46
L-2 An illustration of the residual oil contents related to
Oil-CREP I injection in recent test trials 47
IV
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Tables
Number Page
1 Dutch Reference Levels Used for the Judgement of Soil Contamination 2
2 Soil Washing Installations Visited by the Alliance/EPA
Field Team in March 1988 in the Netherlands and the
Federal Republic of Germany 4
3 Incineration Installation Visited by the Alliance/EPA
Field Team in March 1988 in Belgium 5
4 Site Remediation Techniques (Other Than Soil Washing)
Visited by the Alliance/EPA Field Team in March 1988
in the Netherlands and the Federal Republic of Germany 6
A-1 Results of Electrochemical Reduction of Three Organohalogens
Tested at TNO 10
B-1 Some Results from the TNO Bioreactor System (Batch Process) 11
D-1 Results of Soil Cleanings Performed by Heijmans
Milieutechnick B.V 18
F-1 Results of Water Treatment by the TAUW Biocontactor 21
G-1 Typical Removal Efficiencies for the HWZ Soil Cleaning
Technique 26
H-1 Results of Laboratory and Pilot-Scale Studies Using the
Heidemij Froth Flotation Soil Cleaning Method 29
1-1 Experimental Test Results of PCB Incineration in the HTSI 35
K-1 Performance of the Harbauer Soil Washing System on Sandy Soil 43
K-2 Performance of the Harbauer Soil Washing System on Soils
With High Clay Content 43
L-1 Performance of the Oil CREP System SSC-20A 47
L-2 Performance of the Oil CREP System SSC-20A on Four Different Samples 47
M-1 Results of an EGO-PLUS Biosystem Open Bed Installation at a
Mineral Oil-Contaminated Storage Tank Facility in Altlast 50
M-2 Results of an ECO-PLUS Biosystem Open Bed Installation
at the Diesel Oil-Contaminated FEA Department Grounds in Wedelt 50
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Acknowledgments
This project was sponsored by Mr. Thomas Devine, Director of EPA's Office of
Program Management and Technology. The authors wish to express their appreciation
for the efforts of Mr. Thomas Pheiffer of that office, for his participation in the Phase II
field team and support throughout the project.
The authors acknowledge the cooperation of all the EPA research laboratory,
enforcement, and regional personnel, who contributed to the Phase I document. The
authors also wish to thank Ms. Margaret Brown Nels of Berlin, FRG, and all the foreign
researchers and cleanup firm contacts who contributed to the Phase II field efforts.
VI
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Introduction
The purpose of this program was to identify and
assess international technologies applicable to
hazardous waste site remediation in the United
States. As shown in Figure 1, the program was
conducted in two phases: 1) Phase I - Technology
Identification and Selection; and 2) Phase II -
Technology Review. This report summarizes the
results of Phase II of this program, a thorough
investigation of the most promising technologies
identified by Phase I efforts.
Figure 1. Program structure - The assessment of international
technologies for Superfund applications.
Phase I
Technology Identification and Selection
• 4 Months
• 95 Technologies
• 15 Selected for Phase II
• Phase I - Final Report - March 30, 1988
Phase II
Technology Review and Site Visits
• 2 Weeks
• 15 Technologies Reviewed
• Phase II - Final Report - May 30, 1988
General Approach
The in-depth investigation of the most promising
technologies was accomplished by interviewing
scientists and engineers who are researching or are
knowledgeable of each technology. Laboratories,
facilities and site installations were toured. These
meetings were scheduled by Alliance or organized by
the coordinators of treatment technology research in
each country. These prominent coordinators include
Ms. Esther Soczo, Coordinator of Soil Development
at The National Institute of Public Health and
Environmental Hygiene (RIVM), the major government
research center in Holland; Dr. Ir. K.J.A. de Waal,
Deputy Director of TNO (Netherlands Organization for
Applied Scientific Research); and Mr. Christian Nels,
Director of Research for Umweltbundesamt, (Federal
Republic of Germany's equivalent to U.S. EPA).
During the Phase II investigation, 15 technologies in
three European countries were visited by the field
team, which included Mr. Thomas Nunno and Ms.
Jennifer Hyman of Alliance Technologies Corporation,
and Mr. Thomas Pheiffer of the U.S. EPA, Office of
Program Management and Technology.
Overview of Site Remediation Programs
in Holland, Belgium and Federal
Republic of Germany
Holland (The Netherlands)
The field team began in Holland, a very densely
populated country where much land is below sea
level. Since there is little open space in Holland,
landfilling of wastes is restricted. Remediation of
abandoned sites has become a priority in Holland.
Holland's extensive experience with land and water
management due to high ground water levels has
brought about developments in soil and water
management techniques useful for site remediation.
The Dutch government has set three specific levels
for hazardous contaminants which are used as
guidelines for prioritizing site remediation. Examples
of these levels designated A, B and C, are shown in
Table 1. Soils with contamination above the "C" level,
if treatable at a cost below 250 Dfl/tonne ($135/ton),
must be cleaned and to below "B" level
concentrations. Soil below the "B" level but above
the "A" level may be used as fill, not as farmland.
The Dutch government supports the development of
innovative site remediation techniques by partially
funding cleanup efforts and the research center TNO,
and through the full support of the research and
development center RIVM (National Institute of Public
Health and Environmental Hygiene). Representatives
from the Dutch government and industry are also
active in the NATO/CCMS Pilot Study Demonstration
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Table I. Dutch Reference Levels Used for the Judgment of
Soil Contamination
Concentration level
(mg/kg dry weight)
Component
Polycyclic aromatic hydrocarbons
(total)
Mononuclear aromatics (total)
Mineral oil
Cyanide (total complex)
A
1
0.1
100
5
B
20
7
1,000
50
C
200
70
5,000
500
A = Background level uncontammated soil.
B = Level which necessitates further investigation.
C = Level which necessitates a sanitation investigation.
of Remedial Action Technologies for Contaminated
Land and Ground Water.
Belgium
The Phase I report noted that although the three
regions of Belgium are encouraging development of
regional treatment facilities, little information was
available concerning site remediation efforts. At this
time, very little site remediation work is being
conducted in Belgium due apparently to a lack of
government spending and regulation in this area.
However, a highly useful high-temperature technique
for the treatment of low-level radioactive wastes was
investigated for possible application to difficult-to-
treat hazardous wastes.
The Federal Republic of Germany (West Germany
and Berlin)
Unlike Holland, the Federal Republic of Germany
(FRG) has not yet set limits for the concentrations of
contaminants in soil. Using the Dutch tn-level
system as a guideline, the German State
governments collaborate with responsible parties on
reasonable goals for final concentrations on a site-
by-site basis.
Treatment technology development is promoted by
Umweltbundesamt, the West German equivalent of
the U.S. EPA, through a 50 percent funding program.
Technologies that qualify can receive a 50 percent
loan on capital costs for pilot-plant construction. If
the pilot project is successful, the technology must be
employed and the loan must be repaid. If the plant
fails to reach preset performance goals, the company
does not have to repay the loan. West German site
remediation experts are also active in the NATO/
CCMS Pilot Study Demonstration of Remedial Action
Technologies for Contaminated Land and Ground
Water.
One activity that has helped to stimulate site
remediation in the Federal Republic of Germany was
a mandatory insurance requirement beginning in the
late 1960s for companies with oil and gasoline
storage tanks. These policies have been broadened
to include most hydrocarbon contaminations and have
encouraged development and application of inex-
pensive and effective oil treatment techniques.
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Summary of Results
The field team visited with 12 research groups,
consultants, and manufacturers at 15 locations during
visits to three countries in Europe. The site visits,
conducted from March 21 through April 2, 1988,
during the Phase II effort, are listed below by country:
1. THE NETHERLANDS
A. TNO
i. Electrochemical treatment of
organohalogens
ii. Bioreactors
B. RIVM
i. Overview of soil treatment research in the
Netherlands
ii. In situ biorestoration
C. Heijmans Milieutechniek BV - soil washing
by extraction
D. TAUW Infra Consult BV
i. In situ washing of Cd-polluted soil
ii. Rotating Biological Contactors for
treatment of pesticides in ground water
E. HWZ Bodemsanering - soil washer
especially for cyanides
F. Heidemij Uitvoering BV.
i. Mobile soil washer using froth flotation
ii. Steam stripping in situ
iii. Cum-Bac on-site composting
technique
2. BELGIUM
A. SCK/CEN High Temperature Slagging
Incinerator
3. FEDERAL REPUBLIC OF GERMANY
A. Hannover Umwelttechnik GmbH - Vacuum
extraction of organics in soil
B. Umweltbundesamt - overview of soil
treatment research in the FRG
C. Harbauer GmbH - soil washing using low
frequency vibration
D. TBSG Industnevertratungen GmbH - soil
cleaning on-site using the surfactant "Oil
CREP"
E. Umweltschutz Nord GmbH
i. On-site composting using bioreactors,
special substrate and reed beds
ii. In situ biorestoration
The results of the individual site visits are
summarized below. Capsule summaries of each site
visit, presented in Appendices A through M, include a
brief process description, discussion of process
limitations, performance data, costs, and status of
process development.
In general, the Phase II efforts were successful at
identifying site cleanup technologies not currently
used in the United States, as well as unique
applications of techniques used in the United States.
Among the most important Phase II findings were five
different soil washing techniques in Holland and the
FRG. Another key finding was the High Temperature
Slagging Incinerator (HTSI) technology reviewed in
Belgium. In addition, the field team reviewed unique
applications of in situ biological treatment and
composting techniques, vacuum extraction and in situ
air stripping, in situ extraction of cadmium from soils,
application of rotating biological contactors, and
electrochemical dehalogenation techniques. All of
these unique applications and research should
contribute significantly to our knowledge base of site
cleanup technologies in the United States.
Soil Washing Equipment Findings
The field team reviewed five high throughput soil
washing technologies in Holland and the FRG.
Characteristics of these technologies are summarized
in Table 2, including throughput, unit operations,
reject particle size and costs.
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Table 2. Soil Washing Installations Visited by Alliance/EPA Field Team in March 1988 in the Netherlands and the Federal Republic of Germany.
Installation
Heijmans Miheutechmek
b.v. Rosmalen, the Neths.
HWZ Bodemsan-enng
Amersfoort, the Neths.
Heidemij Uitvoenng b.v.'s-
Herto-genbosch, the
Neths
Harbauer GmbH Berlin,
FRG
TBSG Industnevertretungen
GmbH- Oil CREP System
Bremen, FRG
Rated
Throughput
1 1 tons/hr
22 tons/hr
30 tons/hr
16.5-22
tons/hr
44 gpm,
New 88
gpm plant
planned
Principal Operations
• Particle sizing
• Scrubbing with detergents
and oxidants
• Flocculation
• Precipitation
• Particle sizing
• Scrubbing with detergents
• Flocculation
• pH adjustment
• Carbon filters
• Particle sizing
• Froth flotation with
cleaning agents
• Washing
• Particle sizing
• Low-freq. vibration with
extrac-tants
• Washing
• Water treatment by
flotation, air stripping, ion
exch. and activated
carbon
• Particle sizing
• Washing with Oil CREP I
• Solid/liquid separation
Particle
Reject Fixed or
Size Transportable
< 63 um Transportable
but fixed
< 63 urn Transportable
but fixed
<50 urn Mobile, but
will be fixed in
the future
< 1 5 urn Fixed
< 100 urn Mobile
Pollutants
Treated
Cyanides
Heavy metals
PCAs
Mineral oil
Kerosine
Cyanides
Heavy metals
aromatics
Solvents
CI-HCs
Cyanides
Heavy metals
PCAs
Oils
CI-HCs
Pesticides
Organics
Phenol
PAH
Org-CI cmpds
PCBs
Extractables
HCs
PAHs
Extr. Hal-org.
Refractory
Pollutants
CI-HCs
Aromatics
Oily cmpds
Br cmpds
PAHs
PCBs
HCH
Some heavy
metals
Heavy metals
PCBs
FI-HCs
Cyanides
Heavy metals
Treatment Fee per
Ton
$73-91
$102 at max
30% < 63 urn
$53 plus
$2.50/ton for each
% < 63 urn, up to
20%
$90-155, 2200
tons is mm treated
$136 (excludes
residue disposal)
$82-109
excluding disposal
of residues, 3920
cu yds mm treated
Sludge
Disposal
Costs per
Ton
$136
$136
as high
as $182
Sludge
stored
to date
$6K/day
sludge
treatment
Capital
Costs
New 33
tons/hr plant
planned,
$4.5 million
$3 million
$3 million
$4.5-6
million
Not known
at this time
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A key similarity among all of the units was that they
operate on the principle that most of the contaminants
are sorbed to the fine materials (< 63 nm) and
segregation of these materials from the other size
fraction "cleans" the soil. Some of the units (i.e., the
Heijmans unit), employed very simple particle
separation and wash water treatment technologies,
while others (Harbauer and Oil CREP) employed
more sophisticated extractants and cleaning agents. A
major consideration of all washing techniques is the
fact that as particle reject size decreases, so does
sludge residue generation. Cleaning efficiency tends
to decrease with decreasing particle size.
Most of the soil washing companies noted that their
practical upper limit of fines (< 63 pm) was 20 to 30
percent in the soil to be cleaned. Because the
proportion of fines present increases the generation
of sludge, treatment costs tend to increase for finer
grained soils. The Harbauer technology shows an
advantage of potentially generating less sludge;
however, the additional costs of wash water treatment
employed for that technology make it slightly more
expensive than the other soil washing technologies
reviewed.
High Temperature Slagging Incineration (HTSI)
The Belgium HTSI technology shows promise as a
transferable technology for high hazard waste
streams and fibrous asbestos wastes. Details of this
technology are summarized in Table 3. Very high
combustion efficiency and off-gas cleaning
efficiencies along with very stable slag residues make
this technology very attractive. The high treatment
costs $3.50/kg ($1.60/lb) associated with the low
throughput 60 kg/hr (133 Ib/hr) unit make the
development of higher throughput units critical to its
successful importation to the United States' market.
Other Unique Applications of Site Remediation
Technologies
During the trip, many other successful applications of
conventional and novel treatment technologies were
observed, on both a research scale as well as full-
scale. Table 4 outlines the important characteristics of
these technologies.
Biorestoration research and full-scale applications of
bioremediation technologies have advanced in
European countries much as it has in the United
States. During visits with two research organizations
(TNO and RIVM) and three consulting companies, the
field team observed many successful studies and
applications of biological treatment technologies,
(mostly aerobic systems).
In situ bioremediation was being researched and
tested at RIVM and applied by Heidemij in Holland.
RIVM found that hydrogen peroxide was a suitable
oxygen source for in situ bioremediation.
Biodegradation rates of 10 mg C/kg day were
obtained by RIVM. At a contaminated gasoline site,
bioremediation will be used for cleanup to the Dutch
A limit of 20 mg/kg.
Ex situ or on-site bioremediation technologies are
being researched and applied in both Holland and the
FRG. TNO showed successful results from laboratory
experiments for both wet slurry biological treatment
systems and dry compost-type systems. This
fundamental research showed diffusion of organics
from the soil particles to be the rate limiting step.
Full-scale applications of compost-type systems
were being applied by both Heidemij (Holland) and
Umweltschutz Nord (FRG). Costs for full-scale ex
situ composting applications were found to be in the
range of $82 to $136/ton.
A Rotating Biological Contactor (RBC) application
employed by TAUW in Holland was used on
pesticide-contaminated ground water containing
chlorinated organics. TAUW found that the RBC
system reduced activated carbon requirements by 92
percent, and decreased remediation costs by 30
percent.
Other physical/chemical treatment research reviewed
included an in situ cadmium extraction project by
TAUW and an electrochemical dehalogenation
research project by TNO. The cadmium extraction
Table 3. Incineration Installation Visited
Company/
Institution
SCK/CEN
Mol, Belgium
Technology
High-
Temperature
Slagging
Incineration
Pollutants
Treated
All
(originally
for low-
level
radioactive
wastes)
by Alliance/EPA Field Team in March 1988 in Belgium
Medium
Treated Principal Operations
All • Waste shredding and
full mixing
• Combustion at 1400°C
into molten slag
• Slag granulation by
quenching
• Off-gas treatment by
teflon bag filters,
scrubber and HEPA
filters
Size and
Scale of Time of Treatment Capital
System Treatment Costs Costs
Full 133 Ib/hr $1 60/lb $6 million
(less if built
w/out
extensive
off-gas
treatments)
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Table 4. Other Site Remediation Technologies Visited by Alliance/EPA Field Team in March 1988 in the Netherlands and the
Federal Republic of Germany
Company/
Institution
TNO-Dept. of
Environmental
Technology
Delft, the Neths.
Technology
Electrochemical
Dechlonnation
Treatment
Pollutants
Treated
Polar and
Ionic
Organo-
halogens
Medium
Treated
Dilute
Aqueous
Waste
Streams
Principal Operations
• Titanium anode
• Woven carbon fiber
cathode
• Membrane between
• Surface active additives
• About 10 A, 60 mins.
Scale
of
System
Bench
Size and
Time of
Treatment
Pilot tests will
be 26 gal/hr
Treatment
Costs
$0.02/gal
Capital
Costs
Not yet
determined
TNO- Dept. of
Process
Technology
Apeldoorn, the
Neths.
RIVM- Soil
and Ground
Water
Research
Laboratory
Bilthoven, the
Neths.
TAUW Infra
Consult bv
Deventer, the
Neths.
TAUW Infra
Consult bv
Deventer, the
Neths.
Bioreactors
In Situ
Biorestoration
Non-
chlor-
inated
hydro-
carbons
Gasoline
Slurried or
dry soil
Soil
In Situ
Cadmium
Removal
Rotating
Biological
Contactors
Cadmium
Pesticides
Soil
Ground
Water
Hannover
Umwelt-
technik GmbH
Waldorf, FRG
In Situ Vacuum
Extraction and
Air Stripping
Volatile
organics
Soil
vadose
zones and
ground
water
• Mixing and aeration Bench Pilot tests will $45/ton
• Nutrients be 11
• Detergents tons/day
• Native microorganisms
• Infiltration of nutrients Full 1961 cu yds, $171/cu
• Water, and 1 ? years yd
• H2C>2 as oxygen source
• Iron extraction unit
• Infiltration of acidic water Full 39,200 cu $63/cu
to leach cadmium yds, 1 year yd
(pH=3.5)
• Ion exchange onsite
• Metal honeycomb disks Full nOgpm Data not
• Compost air filter available
• Sand filtration
• Activated carbon
• PVC slotted wells Full About < $5/ton
extract from vadose 10,000 cu
• Small pump yds, 1 year
• Activated carbon column
• Compressed air injected
into ground water
Not yet
determined
$336,000
$2.5
million
Data not
available-
total costs
reduced
30% with
RBC
$1500,
depending
on scale of
project
Umweltschutz
Nord GmbH
Ganderkesee,
FRG
On-site
Composting
Non-
chlor-
inated
hydro-
carbons
Soils "Unique substrate
• Nutrients, microbes
• PET liner with leachate
collection
• Aeration
• Greenhouse cover
Full 131 cu yds
per bed, 6
months with
greenhouse
$90/ton Varies
project employed in situ hydrochloric acid leaching of
cadmium from over 30,000 m.3 of soil. The acid
leachate was purified by ion exchange and reused.
The treatment cost was estimated to be $75/ton of
soil. The electrochemical dechlorination research is
currently nearing the end of the bench-scale phase.
The potential application to site remediation is in the
detoxification of complex organohalogens in the
aqueous phase. Current costs are projected to be
$0.023/gal. Full-scale research will begin June
1988.
Numerous full-scale projects involving in situ
vacuum extraction and air stripping of volatile
contamination were reviewed in the FRG. Hannover
Umwelttecknick (HUT) has installed over 300 vacuum
extraction installations for vadose zone
decontamination. HUT has also developed a unique in
situ air stripping system for removing volatiles from
ground water in conjunction with vacuum extraction.
Treatment costs for the HUT system are less than
10DM/tonne ($5/ton).
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Conclusions and Recommendations
Soil washing experience in the Netherlands and the
Federal Republic of Germany (FRG) has shown that
soil washing can be conducted on a large-scale at
costs substantially lower than those of incineration
(with notably less effectiveness). Although most of the
technologies generate 10 to 20 percent of the initial
volume as sludge, depending on the fines content,
work is being conducted in the FRG to improve
effectiveness of soil washing on fine materials and to
reduce sludge generation. Typical cleaning
efficiencies for soil washers ranged from 75 to 95
percent removal, depending on the contaminant.
Although the authors believe that soil washing
technologies could be used effectively in the United
States to significantly reduce landfilling of CERCLA
site soils, it is unlikely that domestic or foreign
companies will invest in this market until a uniform set
of soil cleanup criteria is developed.
Biological treatment technologies have been shown to
be useful both for polishing to lower concentrations
using in situ treatment, and for gross removals of
organic materials using RBC and composting
systems. Efforts should be made to encourage the
use of these types of systems in the United States.
High temperature slagging incineration appears to be
a viable technology for application towards high
hazard wastes and asbestos wastes in the United
States. The licensing and construction of units in the
United States should be tracked to encourage
evaluation of domestic installations.
In situ vacuum extraction of volatile organic
compounds is a well-known technology in the United
States. Applications in the FRG include the use of in
situ air stripping of volatiles from ground water into
the vadose zone and their subsequent removal by the
extraction wells. Such vacuum extraction applications
and other innovations such as bioaugmentation
should be encouraged in the United States.
The apparent success of this relatively short-
duration, technology assessment program indicates
that despite the wealth of information available in the
United States, there is much to be learned from
ongoing work in foreign countries. The authors
recommend that further efforts be made to encourage
the transfer of European site remediation technologies
through improved literature dissemination and seminar
presentations at symposia. It is also recommended
that results of research identified under this project
and the NATO/CCMS Pilot Demonstration program be
closely monitored over the next few years.
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Appendix A
Research on Electrochemical Treatment of Organohalogens in Process
Wastewaterat TNO
TNO Division of Technology for Society
P.O. Box 217
2600 AE Delft
The Netherlands
Dr. - Ir. D. Schmal
Dept. of Environmental Technology
Tel.: 011-31 (15) 69 60 87
Process Description
This research project focuses on the electrochemical
dechlorination of organohalogens. In the laboratory,
simulated dilute wastewater was passed between a
platinized titanium anode and a woven carbon fiber
cathode (fiber diameter = 10 pm). The applied voltage
causes the chlorine atoms of the organohalogens to
be replaced by hydrogen atoms, thus reducing their
toxicity and increasing their biodegradabihty.
Electrochemical treatment is designed to treat ionic or
polar organohalogens which are, in general, difficult to
decontaminate by adsorption or stripping. It is also
more appropriate for dilute wastewaters or wash
waters, where destruction by incineration, for
example, would be too costly.
A diagram of the apparatus used by Dr. Schmal in the
laboratory at TNO is shown in Figure A-1. The
reactor consists of two compartments separated by a
Nafion 425 membrane. Each compartment is 10 cm
long, 2 cm wide, and 0.5 cm deep.
Process Limitations/Performance Data
Electrochemical reduction is only practical for treating
aqueous solutions ot polar or ionic organohalogens.
The process is only amenable to operation in
solutions with low filterable solids content. Fouling
problems may result from solids in suspension or
from polymerization of organics. The process is
currently limited to solutions containing up to 1 g/L
chlorinated organics. Experiments have proven the
technique using batch tests. Pilot-scale tests will be
initiated soon on synthetic wastewater at a treatment
rate of 100L/hr (26 gal/hr).
Another important factor necessary for treatment is
that the contaminant be miscible in the solution.
PCBs will not be treated by this method until a
suitable solvent has been found.
Electrolytic reduction has been successfully applied at
TNO to pentachlorophenol (PCP), p-chloronitro-
benzene (CNB), and dichlorvos (DDVP). Results of
electrochemical reduction of these three con-
taminants are provided in Table A-1. While it takes
only 30 minutes to reduce PCP to below its detection
limit, it takes considerably longer before all
chlorinated secondary products are reduced to the
non-chlorinated phenol. A graph of the formation
and decay of by-products during PCP reduction is
shown in Figure A-2.
The addition of small quantities of surface active
agents improves efficiency, decreasing energy
consumption by 45 percent. These micelle-forming
compounds are patented by van Erkel, et al. (U.S.
No.4,443,309).
Cost
In comparison with electrolysis of metals, which costs
2-5 Dfl/m3 (<$0.01/gal), electrolysis of
organohalogens is expected to be more or less
comparable in cost, about 10 Dfl/m3 ($0.02/gal). The
basis for these costs are 40 percent capital costs, 40
percent energy costs, and 20 percent operation and
maintenance.
Process Status
This bench-scale research on electrochemical
dechlorination of organohalogens was sponsored by
Pielkenrood-Vinitex, a Dutch producer of wastewater
treatment equipment (along with the European
Communities and various Dutch Ministries), so it has
certainly been geared towards practical full-scale
application. Since Phase I of this project has been so
successful, Phase II, which will last from June 1988
through 1989, should show some progress towards
the development of a full-scale continuous
electrochemical reactor. The usefulness of this
technology will probably be proven in Holland first
before intentions for exportation or licensing abroad
arise.
-------
Figure A-1. Diagram of the apparatus for electrochemical
treatment of organohalogens.
Figure A-2. Mole fraction of the phenols during electrolysis
of 2 L of 50 ppm PCP solution (10A).
100 (- Mole Fraction
RESER-
VOIR
60 90 120
-»• Time of Electrolysis, mm
150
Source:
PUMP
Schmal, D., J. van Erkel, and P J. van Duin.
"Electrochemical Reduction of Halogenated Compounds
in Process Waste Water," Electrochemical Engineering,
The Institution of Chemical Engineers Symposium Series
No. 98. p. 262. April 1986.
1. PCP
2 Tetrachlorophenols
3 Trichlorophenols
4 Dichlorophenols
5 Monochlorophenols
6 Phenol
Source Schmal, D., J van Erkel, and P J van Dum
"Electrochemical Reduction of Halogenated Com-
pounds in Process Waste Wateer " Electrochemical
Engineering, the Institution of Chemical Engineers
Symposium Series No 98 April 1986
Table A-1. Results of Electrochemical Reduction of Three Organohalogens Tested at TNO
Cathodic Energy
Contaminant
PCP
CNB
DDVP
Initial Cone. Final Cone.
(ppm) (ppm)
50 <0.5
30 <0.1
560 <1
Current Time Consumption Toxicity
(amps) (mm) (kWh/gal) Notes
10 30
10 60
1 60
0.14 Toxicity
reduced
95%
0.11
0.0030 value =
56 ppm
Remarks
1 L in 0.1 M sodium sulfate/0.1 M sodium
hydroxide solution
1 L in 0.1 M sodium hydroxide solution
1 L in 0.1 M sodium sulfate solution
Source: Schmal, D., J. van Erkel, and P.J. van Dum. "Electrochemical Reduction of Halogenated Compounds in Process Waste
Water," Electrochemical Engineering, The Institution of Chemical Engineers Symposium Series No. 98. April 1986.
10
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Appendix B
Research on Decontamination of Polluted Soils and Dredging Sludges in
Bioreactor Systems at TNO
TNO Division of Technology for Society
P.O. Box 342
7300 AH Apeldoorn
The Netherlands
Mr. Guus J. Annokkee
Dept. of Process Technology
Tel.: 011-31 (55) 77 33 44
Process Description
A bioreactor is primarily a mixing apparatus whose
main function is to increase the availability of
contaminants and nutrients to the microorganisms for
accelerated biodegradation of these hazardous
compounds. TNO studies have found that since the
microorganisms are bound to the soil particles, mixing
is one of two important contributors to high
biodegradation rates. In their research on bioreactor
systems, TNO also uses detergents to enhance the
bioavailability of the contaminants.
The factor other than bioavailability which contributes
to high biodegradation rates is the ability of the
microorganisms to degrade the particular
contaminants. Microorganisms specially suited to
break down certain toxic compounds can be
cultivated in the laboratory, but where a site is old,
appropriate microorganisms are usually already
present in the soil. The availability of nutrients and
oxygen is not the controlling factor in accelerating the
biodegradation rate but is necessary for maintaining it.
The bioreactors are continuously mixing and aerating
the soil and operate at ambient temperature. The
bioreactor design employed by TNO could not be
viewed because the technology is protected by their
sponsors.
Two types of bioreactor treatments are employed by
TNO: dry and wet bioreactor systems. The dry
bioreactor system is similar to a composting type of
operation, while the wet bioreactor is more closely
compared to an aerobic activated sludge system. The
dry bioreactor operates under an ambient moisture of
15 to 20percent and requires no dewatering step after
treatment. In the wet bioreactor, the soil is handled as
a slurry. Slurries are easier to process in that they
can be pumped, but must be dewatered if the soil is
to be reused. Both wet and dry bioreactor systems
are effective. However, future TNO research is
focusing on the dry (composting type system) due to
the advantages noted above. A key finding of TNO's
research has been that the biodegradation reaction is
rate-limited primarily by diffusion of the organic
material to the surface of the soil particles.
Bioreactors are naturally applicable to biodegradable
contaminants such as mineral oils, PCAs, and other
non-chlorinated hydrocarbons. Microorganisms that
secrete acid are used to remove contaminants that
are leachable, such as heavy metals. A wide variety
of soil types, from sand to loam and clay, can be
cleaned in the bioreactor.
Process Limitations/Performance Data
Bioreactors have been found to be effective on
contaminants that are biodegradable. Chlorinated
hydrocarbons, as a result, have not been effectively
treated by this method. Results of TNO's bioreactor
degredation of various organic pollutants in a variety
of soil types are shown in Table B-1. These
performance data are from batch laboratory studies
on wet and dry bioreactors performed at TNO.
Table B-1. Some Results from the TNO Bioreactor System
(Batch Process)
Bioreactor
type Soil type
Dry
Dry
Sand
Sand
Contam-
inant
Cutting oil
Diesel
fuel
Concentration (mg/kg dry soil)
Day 0
3,000
4,200
Day 3
980
1,800
Day 14
680
900
Wet/slurry Loamy Cutting oil 26,000
sand
Wet/slurry Loam Cutting oil 65,000
Wet/slurry Loam PCAs 3,900
9,000
1,200
12,000
1,700 300
Source: Annokkee, G. "Status of TNO Bioreactor System for Soil
and Subaquatic Soil Decontamination." Handout from
meeting with Alliance field team. March 22, 1988.
One advantage bioreactors have over soil washing
techniques is that they are able to treat large
quantities of fines. Most problems that arise in
11
-------
bioreactor installations are operational in nature, such
as pump failure or line clogging.
Cost
Because of the early stage of bioreactor research,
actual capital, operational and maintenance cost data
are not available. Prices are expected to be about
100 Dfl/tonne ($45/ton). Actual treatment costs are
dependent on the period of treatment necessary.
Bioreactor research at TNO has focused on
minimizing of residence time necessary for effective
treatment.
Process Status
TNO is nearing completion of 2 years of laboratory-
scale studies. Pilot-scale experiments with a
throughput of 10 tonnes/day (11 tons/day) are
currently in preparation. Laboratory-scale studies
have been batch-type. Since the microorganisms
are bound to the soil particles, system
configuration(batch or continuous) does not affect the
biodegradation rate. TNO estimates that commercial
systems will be batch-operated, have a capacity of
200 or 500 tons, and have treatment time of 10 to 14
days. Depending on the type of bioreactor, even
larger systems are possible. Bioreactors can be
constructed to be stationary or mobile.
Bioreactors are a simple technology and, therefore,
scale-up of the system to allow high throughput
should not be difficult. Research will continue at TNO
on treating a greater variety of contaminants,
increasing bioavailability of the contaminants, and
scaling-up the bioreactor system. This research
project is funded 30 percent by the Dutch
government and 70 percent by Heidemij Uitvoering, a
site cleanup contractor. Heidemij has the rights to the
technology, and their intentions towards licensing or
exporting the technology are not yet formulated.
12
-------
Appendix C
In Situ Biorestoration of Contaminated Soil Research at RIVM
RIVM - National Institute of Public Health
and Environmental Hygiene
P.O. Box 1
3720 BA Bilthoven
The Netherlands
Ir. Reinier van den Berg, Jos H.A.M. Verheul
Soil Biochemistry and Microbiology
Soil and Ground Water Research Laboratory
Tel.: 011-31 (30) 743338
Ms. Esther Soczo, Coordinator, Soil Development
Laboratory for Waste Materials and Emissions
Tel.: 011-31 (30) 743060
Process Description
The following discussion briefly presents the status of
in situ biorestoration research currently being
conducted at RIVM. Most of the research to date has
been laboratory-scale, however, a NATO/CCMS
demonstration study at Asten is scheduled to begin in
June 1988.
Undisturbed soil columns were taken from deep
layers in the Asten site contaminated with gasoline.
Experiments were carried out by the Soil
Biochemistry and Microbiology group at RIVM on
these columns to determine the optimal conditions for
biodegradation. In order to stimulate biodegradation,
soil columns were percolated with a variety of
nutrients and 02 sources. pH and the addition of
detergents, sodium acetate and microorganisms were
all tested for their effects on biodegradation rate.
Results showed that it is possible to increase the
biodegradation rate, measured as carbon dioxide
production, from 1 to 10 mg C/kg day. The
Figure C-1 Infiltration, withdrawal and treatment setup proposed by RIVM for the Asten site.
Infiltration
100-1000
(mg Gasoline/kg Soil)
•A 6
y/////////////////////////////////7//77//. Clay Loam Layer
Source van den Berg, R , E R Soczd , J H A M Verheul, and D H Eikelboom "In Situ Biorestoration of a Subsoil Contaminated
with Oil " RIVM Report No 728518003 p 24 November 1987
13
-------
degradation activity was most enhanced by the
addition of seeding material from a landfarm. The
addition of sodium acetate to build biomass,
saturation with water, the addition of phosphate and
nitrate, buffering, and a neutral pH all contributed to
favorable conditions for biodegradation. Detergents
had a negative effect, and the source of the nitrogen,
whether it was KNOa, NhUNOa, NHUCI, or
(NH4)2SO4, had no effect. As alternative oxygen
sources, hydrogen peroxide (H202) was suitable,
whereas nitrate slowed biodegradation. Results of the
laboratory-scale research supported the assumption
that the rate-limiting step was the availability of the
oil components to the microorganisms.
A diagram of the infiltration and withdrawal system
proposed for the Asten site is shown in Figure C-1.
This system will enhance the leaching and
biodegradation of gasoline contaminating the site by
the addition of nutrients and oxygen and extract iron
from the withdrawn water using a small water
treatment unit.
Process Limitations/Performance Data
Biorestoration, in general, is only effective on
biodegradable contaminants and is difficult in soils
with a high clay and/or organic carbon content.
Experimental results from one laboratory-scale study
are shown in Figure C-2. In this graph, the effects of
water saturation, nutrient addition and seeding with
KONI soil (from a landfarm) on biodegradation of
gasoline is shown. Although acceleration of the
biodegradation process from 1 to 10 mg C/kg day
was found to be possible, this rate is still relatively
slow. This is apparently due to the fact that very few
microorganisms occur naturally in the site.
Some possible limitations that could arise in carrying
out the treatment are problems due to cold or wet
weather extremes, or mechanical problems with
pumps or the ground water treatment unit. Clogging
of the wells at the Asten site is not likely because the
soil layers to be treated are mostly sand, with less
than 0.05 percent organic material. Part of the
installation includes hydrological isolation of the
contamination vertically and horizontally. Special
Figure C-2. Biodegradation of gasoline measured as CO2-production (mg C/kg). Gasoline concentrations: 3000-
5700 mg C/kg. Effects of water saturation, nutrient addition (CNP ratio 100:10:1 and 100:10:5) and
seeding with KONI soil: 50 g/kg.
Carbon dioxide
production
[mg C/kg]
(Thousands)
Blanc -|- Water saturation
/^ C:P 100.5
o Water, CNP 100:10:1
Seeding with KONI
Source: van den Berg, R., E.R. Soczo, J.H.A.M. Verheul, and D.H. Eikelboom. "In Situ Biorestoration of a Subsoil Contaminated
with Oil." RIVM Report No. 728518003 p. 16. November 1987.
14
-------
attention will be paid to the percolation under the
buildings on the site, where the contamination has
already begun to spread.
Cost
Conventional cleanup for this site, such as extraction
or incineration, would typically cost 1.2 million Dfl
(about $672,000). In situ biorestoration, including
ground water treatment, is expected to cost half this
figure or about $336,000. These figures do not
include the costs of sampling and analysis necessary
for monitoring the progress of the installation, or the
cost of seeded soil which was determined not to be a
cost-effective additive. Since 1500 m3 (1961 cu yd)
of soil is contaminated, costs will be 400 Dfl/m3
($171/cu yd).
Process Status
A full-scale system will be installed beginning in
June 1988 in the gasoline-contaminated site at
Asten, in the province of Noord-Brabant. This
remediation is a NATO/CCMS Pilot Study
demonstration project whose research began at RIVM
in 1985. The cleanup operation is expected to take
1-1/2 years to reach the Dutch "A" limit of 20
mg/kg. This cleanup period is based on a daily
circulation of water calculated at 1,850m3 (488,400
gals) with a daily degradation rate of 10 mg C/kg.
The remediation program of RIVM at the Asten site
will not provide any innovative technologies to be
licensed for marketing abroad. It will provide, if
successful, valuable information on soil chemistry and
soil microbiology in the field, as well as a practical
and less expensive alternative to extraction or
incineration treatment for gasoline-contaminated
soils.
RIVM is a government center for research and
development of all aspects of public health. They also
advise the various government Ministries and provide
the service of information exchange for industry. The
laboratory research done for this remediation project
is just one part of a 4-year, 56 million Dfl ($31.4
million) Soil Research Program started in 1987. The
Environment, Agriculture, Water Management, and
Education Ministries are involved with this research
program, which is part fundamental science research
and part technological development.
15
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Appendix D
Heijmans Soil Washing Operation
Heijmans Milieutechniek b.v.
Graafsebaan 13
Postbus 2 5240 BB Rosmalen
The Netherlands
Ing. W.P.J. Kemmeren, Assistant Director/Mr. C.
Jonker
Tel.: 011-31-4192-89111
Process Description
Heijmans has developed a simple semi-transportable
soil washer capable of handling 10 tonnes/hour (11
tons/hour) of soil. Like most soil washers, the
Heijmans soil washer operates on the principle that
most contamination is adsorbed to the fine soil
particles. Thus, the Heijmans soil washer consists of
several particle sizing steps with the goal of removing
the fines < 63 urn and disposing of that fraction as a
sludge byproduct, while the coarser fractions are
further washed and used as clean soil.
The soil cleaning plant of Heijmans wet-sieves out
coarse material > 100mm and rubble > 5 mm first to
allow particles < 5 mm to be washed in the scrubber.
The slurry is extensively mixed in the scrubber with
extracting agents and oxidizing chemicals. A flotation
unit is then used to separate out organic constituents,
which must be disposed of. Finally, hydrocyclones
separate out cleaned sand, 63 jam < x < 5mm,
which is commonly used in asphalt by Heijmans'
road-building division.
The scrubbing water and contaminated fines < 63
urn are passed through a tiltable plate separator in
order to extract out oil and silt < 63 pm. The water is
further treated by coagulation, flocculation and
precipitation, and then Heijmans uses flotation to
remove additional solids. The type of chemical
additives used to initiate coagulation, flocculation, and
precipitation varies with the types of contaminants
present. Water is completely recirculated within the
system. A flow diagram of the process is shown in
Figure D-1.
Process Limitations/Performance Data
Heijmans' soil washer can be applied to soils
containing:
• Cyanides;
• Water-immiscible and low-density
(S.G. < 1.0) hydrocarbons;
• Heavy metals
(such as Cr, Cd, Cu, Ni, Pb, Zn); and
• Combinations of these contaminants.
Heijmans accepts soils with fine fractions < 63 jam
up to 30 percent, but their process works best on
sandy soils with a minimum of humus-like
compounds. Because no sand or charcoal filters are
employed by Heijmans, the system is not able to treat
such contaminants as chlorinated hydrocarbons or
aromatics. Like most soil washing techniques, the
throughput and cost of treatment is dependent on
quantity of fine fractions (< 63 urn) in the soil to be
cleaned.
The system has had its greatest success treating soil
contaminated by cyanides (CN). Heijmans adds
hydrogen peroxide (H202) into the scrubber to react
with CN to form C02 + NH4. In one experiment, CN
at a concentration of 5,000 to 6,000 mg/kg dry soil
was reduced to 15mg/kg. A table showing the results
of the Heijmans soil washer on seven different types
of contaminated soil is shown in Table D-1.
Costs
Operating costs at Heijmans average 140-180
DfI/tonne ($73-91/ton) for typical soils with 10 to 15
percent fines < 63 iam, but can go as high as 400 Dfl
per tonne ($205/ton) for very heavy metal-laden
soils. At their maximum accepted level of 30 percent
fine fraction < 63 jam, costs would be about 200
Dfl/tonne ($102/ton). These costs include landfilling
abroad of the toxic and organic residues at a cost of
250 Dfl/tonne ($136/ton).
Capital costs for a second generation plant being
constructed by Heijmans, with a throughput of 30
17
-------
Figure 0-1. Process scheme of the installation of Heijmans Milieutechniek b.v. Adapted from: TNO - Assink, J.W. and W.J.
van den Brink. 1st International TNO/BMFT Conference on Contaminated Soil. Utrecht, The Netherlands.
November 11-15,1985.
MAKE-UP • • OXIDIZING
EXTRACTING : : CHEMICALS
AGENT f t 1 *• GRASS' COKE
DRY AND WET
I
COARSE
MATERIALS
>100 mm
>5 mm
CONTAMINATED
SOIL
^. SCRUBBER
(INTENSIVE
MIXING &
CHEMICAL
OXIDATION)
FLOCCULANTS —
COAGULANTS
FLOCCULANTS
PRECIPITANTS
PH (8.5)
SOLIDS. SLURRY
SIEVE -4 1
/ k HYDROCYCL
( *
t
TILTABLE > OIL
* PLATE
SEPARATOR > SILT <
V
COAGULATION
AND
FLOCCULATION
w _
FLOTATION
W
/MAIMI y\ i mi Jin
, ETC.
ONES ^ DEWATERING
SIFVF ~|
I
T
CLEANED
SAND
< 63 nm)
b DOUBLE
WIRE
PRESS
DOUBLE 1
WIRE V
PRESS
MINERAL
1 SLUDGE
Table D-1. Results of Soil Cleanings Performed by
Heijmans Milieutechniek b.v. (Analyses
performed by an independent laboratory)
Before After
Site Soil type Contaminant (mg/kg) (mg/kg)
Galvanizing
Fuel drilling
Galvanizing
Gasworks
Gasworks
Diesel fuel
Galvanizing
Silt
Sand
Coarse
sand
Fine sand
Fine sand
Coarse
sand
Silt
Fine Sand
Coarse
sand
Total
Cyanide
Chrome
Nickel
Zinc
Kerosine
Total
cyanide
Chrome
Cadmium
Copper
Nickel
Lead
Total
cyanide
Total PCAs
Mineral oil
Total
cyanide
Zinc
250-500
43-45
250-890
460-720
5,000-
7,000
400-1 ,000
100-2,500
4-18
100-250
100-600
100-450
80-220
250-400
3,000-
8,000
75-300
160-170
10-15
11-15
40-70
140-200
80-120
6-10
70-120
0.5-1.4
25-60
50-80
20-70
5-15
0.5-10
90-120
7-10
50-80
SLUDGE
tonnes/hour (33 tons/hour), is expected to be 8 million
Dfl ($4.5 million). Included in this price is construction
of a paved storage area for soils and a runoff
collection and treatment system.
Process Status
The soil washing unit on the site of the Heijmans
headquarters in Rosmalen was built in 1985 as a
pilot-scale transportable unit. It has an average
throughput of 10 tonnes/hour (11 tons/hour). Due to
the complexities of attaining permits in Holland for the
transport and operation of a mobile hazardous waste
treatment unit, the soil washer has become a fixed
operation. Heijmans will begin construction in May
1988 of a full-scale unit with a throughput of 30
tonnes/hour (33 tons/hour). This new facility will be a
fixed unit, probably located in Moerdijk, near one of
the most contaminated areas of Holland. Heijmans
has not sought to license or import their soil cleaning
technology abroad.
Translated from the brochure "Heijmans Milieutechniek b.v.
Bodemsanenng, Installatie Voor Het Remigen Van Grand," January
1988.
18
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Appendix E
In Situ Cadmium Removal and Onsite Treatment by Ion Exchange
TAUW Infra Consult B.V.
P.O. Box 479
Handelskade 11
7400 AL Deventer
The Netherlands
L.G.C.M. Urlings - Head,
Research and Development
Tel.: 011-31-5700-99911
Process Description
TAUW Infra Consult B.V. has applied an in situ
cadmium leaching technique to a 30,000 m3 (39,200
cu yds) site in the Netherlands. The following
discussion presents a brief synopsis of this
successful project.
Cadmium is desorbed from the soil in situ by leaching
with hydrochloric acid (HCI, 1Q-3 mol, pH = 3.5).
Wells and drains were installed to establish a system
for infiltration and withdrawal. Horizontal drains were
used instead of vertical deep wells in order to get
straight ground-water flow lines. A cross-section of
the infiltration and withdrawal system installed by
TAUW is shown in Figure E-1.
The Cd-contaming percolate is pumped to a water
treatment system housed on-site. Ion exchange was
the technique chosen to remove the Cd from the
acidic percolate. The resin used is a Rohm and Haas
IMAC GT-73 and is regenerated with a 5 percent
HCI solution. The cleaned acidic water is then in-
filtrated again into the cadmium-polluted soil. A
schematic of the water treatment plant is shown in
Figure E-2.
TAUW divided the site into five compartments. The
first compartment was successfully cleaned between
August and December 1987. By October 12, 1987, all
the soil samples showed Cd concentrations equal or
less than 1 mg/kg dry soil, and the Cd concentration
in the percolate was 10 pg/L Acidification of the
infiltrate was stopped, and reneutralization of the soil
was started with NaOH at a pH of 8.5. When the
percolate Cd concentration of every drain was below
the detection limit (< 10 jag/L), neutralization was
stopped and the installation moved to the next
compartment. Cleanup of the first compartment was
so successful that the final four compartments are
being treated together.
Process Limitations/Performance Data
TAUW expected to encounter problems with the
installation due to freezing over the winter, however
no problems were encountered. The thermal mass of
the earth prevented the in situ operations from
freezing up, apparently aided somewhat by a mild
winter.
A limitation inherent to the use of ion exchange is the
necessity to treat the concentrated regenerant.
TAUW's infiltration and withdrawal scheme simply
extracts the contaminant and concentrates it into a
CdCI salt solution. The regenerant salt solution is
then treated off-site. This system also has the risk
of allowing or even encouraging further movement of
the plume. If the remediation continues as scheduled,
TAUW will have cleaned the area just before the
plume would have reached a ground-water source
of drinking water which is near the site. TAUW was
fortunate to have found an ion exchange resin that
removes cadmium effectively at a low pH.
Cost
In situ remediation was selected over conventional
sanitation for cost reasons. The entire project will cost
approximately 4 million DM ($2.5 million). The whole
treatment involves 30,000 m3 (39,200 cu yds) of soil
within an area of 6,000 m2 (7,200 sq yds), and a total
Cd content of the soil estimated at 725 kg (1,600 Ibs).
Thus the treatment cost is $83/m3 ($63/cu yd) or
approximately 80 percent of the cost of soil washing.
Process Status
This operation is a full-scale, in situ remedial action,
ongoing since June 1987, with completion anticipated
for June 1988. In their capacity as a consultant for
Mourik B.V. of Groot Ammers, Holland, TAUW is not
able to license or export any of the techniques
employed in this installation. Mourik, as the
contractor, owns all the equipment and any
technologies developed as a result of this cleanup.
19
-------
Figure E-1. Cross-section of the infiltration and withdrawal system installed by TAUW for Cd leaching.
pH Control
Drain — 10cm.
Extension of the Drains
-------
Appendix F
Rotating Biocontactor for Ground Water Pretreatment
of Pesticide Contamination
TAUW Infra Consult B.V.
P.O. Box 479
Handelskade 11
7400 AL Deventer
The Netherlands
L.G.C.M. Urlings - Head,
Research and Development
Tel.: 011-31-5700-99911
Process Description
TAUW employs rotating biocontactors (RBC) for
treatment of ground water contaminated with
pesticides. Honeycomb metal disks with a diameter of
about 1 meter, are rotated in the contaminated
ground water. Microorganisms colonize on the disks
and biodegrade the organic contaminants. Gaseous
emissions from the RBC are exhausted through a
compost filter to remove organics. To prevent
shocking of the microorganisms, the contaminated
ground water first passes through an equalization
basin before it is pumped into the installation. A
sketch of the on-site installation is shown in Figure
F-1. Ground water from the equalization basin
passes through two RBCs in parallel and as a
polishing step, through two sand filters and three
activated carbon filters.
The RBC can be applied to ground water or leachate
polluted with organic contaminants. One unique
aspect of the TAUW system is that no supplementary
nutrients or microbes were required to initiate or
maintain biodegradation. TAUW believes the age of
the site at which this process is being applied has
established an acclimated microbial population in the
soil.
Process Limitations/Performance Data
RBCs are limited to applications involving
contamination by biodegradable compounds. The
RBC biomass may be susceptible to thermal and
loading shocks.
TAUW applied RBCs to ground water from an old
pesticide manufacturing site. The results from this
cleanup, presented in Table F-1, show removals of
benzene and chlorobenzene exceeding 98 percent.
Figure F-2 shows the loading and removal efficiency
of alpha and gamma HCH isomers. Note that after the
40th day, the loading was increased and the microbes
adapted to the shock, returning to a high removal
rate. The significance of these results is in the
effectiveness of an acclimated aerobic biological
treatment system with regard to chlorinated aromatic
compounds.
Table F-1. Results of Water Treatment by the
TAUW Biocontactor
Influent Effluent Removed Removed
(H9/L) (ng/L) (pg/L) (%)
Benzene
Chlorobenzene
440
470
6
15
434
455
99
98
Source: TAUW Infra Consult B V article, untitled, undated,
sent by L G C.M Urlings to J Hyman, March 2,
1988.
Cost
The purpose of the RBCs was to reduce the amount
of contaminants reaching the carbon filters so that the
life of the carbon would be extended, thus reducing
costs of regeneration or new carbon. Although exact
figures are not available, biological pretreatment
reduced carbon costs to 7 percent of the cost without
pretreatment. When factoring in the cost of the RBC
system, the total costs of ground water purification
were reduced by 30 percent. In addition, the RBC
system would generate significantly less hazardous
residue than the carbon system, consistent with the
waste minimization goals stated in the SARA
legislation.
Process Status
RBCs are mobile units that may be easily used on-
site. The TAUW installation has been operating full-
scale since November 1987. Its throughput is roughly
25 m3/hr (110 gpm). As a consulting firm, TAUW is
not in a position to license or export this technology.
The success of this installation, however, will
hopefully encourage the application of rotating
biocontactors to site remediation in the United States.
21
-------
Figure F-1. Sketch of the TAUW ground water treatment installation near Utrechtg.
Legend
RBC = Rotating Biological Contractor
SF = Sand filter
AF = Activated charcoal filter
CF = Compost filter
Raw
water
infl
effl
Spare
basin
k
Clean
water
To sewer
Road
Stream
Source: TAUW Infra Consult b.v. article, untltled, undated, sent by L.G.C.M. Urlings to J. Hyman, March 2, 1988.
22
-------
Figure f-2. Loading and efficiency over time of the TAUW rotating biocontactor installation.
12
11
10
LOADING,
m3/hr
%
REMOVAL
9 _
7 _
4 _
10
D -TAUW RBC
X - KLEIN RBC
100
90
80
70
60 -
50 -
40 -
30
20
10
0
20
30 40
TIME in days
55
D alpha - HCH
x gamma - HCH
0
20
80
110
40 60
TIME in days
Source: TAUW Infra Consult B.V. article, untltled, undated, sent by L G C.M. Urlings to J. Hyman, March 2, 1988.
23
-------
Appendix G
HWZSoil Washing Operation
HWZ Bodemsanering
Vanadiumweg 5
3812 PX Amersfoort
The Netherlands
Ing. H.C.M. Breek/lr. B. Spruijtenburg
Tel.: 011-31-33-1 3844
Process Description
The HWZ soil cleaning method is based on
techniques of soil washing and particle sizing, along
with a water treatment stream. A flow schematic of
the system is shown in Figure 1. After first crushing
the larger pieces of rubble, pieces 4 mm < x <
50mm are separated out of the stream by wet
sieving. Soil particles 63 urn < x < 4 mm comprise
the main soil stream. These particles are washed of
adsorbed contaminants by scrubbing with detergents
and adjusting the pH to 12-13 by addition of NaOH.
The HWZ soil scrubber employs two mixing
propellers, one mixing up and the other mixing down,
with a net flow downward. A hydrosizer then removes
low density organic and carbon particles such as
wood and rubber. After a dewatering step, the
remaining sand (63 urn < x < 4 mm) is often clean
enough to be used in asphalt batching, or else it must
be landfilled. The fines (< 63 urn) are separated by
hydrocyclones and dewatered in a belt press. It is in
this small volume of fines that the contaminants are
concentrated, and so it must be disposed of as
hazardous waste.
The contaminated scrub water and the overflow from
the wet sieves, hydrocyclones and belt press are
cleaned in the water treatment stream. After residual
fines are removed by sedimentation, the water is
treated in a tank by precipitation, neutralization,
coagulation, and flocculation to remove the dissolved
contaminants. CN can be removed here by the
addition of ferrous sulfate. In the last steps of the
water treatment stream, floating iron hydroxide
particles are removed by sand filtration, and dissolved
organics by activated carbon. The cleaned water is
then discharged or recycled.
Process Limitations/Performance Data
Depending on the chemical additives used in the
flocculation tank, this system can successfully
remove:
• Complex and free cyanides;
• Heavy metals, Pb, Zn, Ni, Cr, As, Hg;
• Aromatics;
• Chlorinated aliphatic hydrocarbons/solvents; and
• Chlorinated aromatic hydrocarbons.
The treatment of soil contaminated with bromine
compounds has been successful on a laboratory-
scale, but has not yet been tested on a full-scale.
Pollutant levels and removal efficiencies achievable
by soil washing strongly depend on the distribution of
the pollutants over the different fractions and the
presence of soil particles other than sand (such as
adsorbing carbon particles) which are difficult to
wash. Where the amount of fine fractions < 63 um is
greater than 20 percent, the volume reduction of the
contaminated soil will not be sufficient to warrant
economical treatment. Where a combination of
pollutants is present, a treatment recipe for the soil
must be tailor-made. HWZ has also had some
problems in extracting PNAs and oily material.
The rate-limiting step in HWZ's soil cleaning
operation is the jet- or hydro-sizer, which can be
slow at times and inaccurate, depending on the type
of soil. HWZ is considering a larger unit to use in its
place. Another unit which HWZ may add to improve
the process is a crusher, which will crush the large
rubble > 50 mm (currently done offsite), in addition
to pulverizing the dense clumps of clay which can
contain a high concentration of absorbed
contaminants. The chemicals in the clay clumps
cannot be reached by scrubbing, but if crushed, can
be taken out in the sludge. Removal efficiencies for
some contaminants are shown in Table G-1.
25
-------
Table G-1. Typical Removal Efficiencies for the HWZ Soil
Cleaning Technique
Contaminant
Input (ppm)
Output (ppm)
CN (complex)
Polynuclear aromatics
Chlorinated
hydrocarbons
Heavy metals
100-250
100-150
20-30
300
5-15
15-20
< 1
75-125
Source: Written correspondence of H C.M Breek to J. Hyman, March
16, 1988.
Maintenance costs can depend on such factors as
the corrosivity of the contaminants treated and the
age of the installation. The present maintenance
costs vary between 50,000 Dfl and 100,000 Dfl/year
($28,000-56,000). Capital costs for such an
operation are estimated to be 4-6 million Dfl ($2.2
to 3.4 million). The development costs and changes
in a later stage are not included in this figure.
Cost
The operating costs of HWZ are typical for soil
washing, in the range of 100-150 Dfl/tonne ($55-
82/ton). This price depends on a variety of factors
including:
• Quantity of sludge < 63 pm;
• Chemical additives necessary; and
• Cleanability of the soil.
One can estimate 100 to 110 Dfl/tonne ($53/ton) for
basic operations, with 5Dfl/tonne ($2.50/ton) for each
percent of soil fraction < 63 pm. At the maximum of
20 percent the cost will, therefore, be 200 Dfl/tonne
($103/ton). HWZ pays at least 250 Dfl/tonne
($136/ton) to dispose of the contaminated fines
abroad.
Process Status
HWZ built this unit in 1984 to be mobile, but the effort
necessary to permit its transport in Holland is so
great that it has become a fixed treatment facility. It is
located on Nordzeeweg, in the western harbor area of
Amsterdam. The unit is full-scale, with a typical
throughput of 20 tonnes/hour (22 tons/hour), this
figure depending on the quantity of fines present.
HWZ is owned by HBG, one of the largest operating
groups in Holland, and is doing a comfortable amount
of business. As a result, they have not needed to
expand their business or technology outside of
Holland. In addition, HWZ holds no United States'
patents on their equipment, so they are not able to
license their technology abroad. Most of the
technology involved in this soil extraction facility HWZ
was borrowed from the mining industry.
26
-------
Figure G-1. HWZ soil treatment scheme.
WATER
20 t/hr
CARBON
PARTICLES,
WOOD, GRASS
0.5 t/hr
SEDIMENTATION
SYSTEM
CONTAMINATED
SOIL
(WITH CYANIDE)
25 Vhr
POLYELECTROLYTE
SLUDGE
CONDITIONER
MECHANICAL
SLUDGE
THICKENING
SLUDGE CAKE
IRON CYANIDE
5-7 t/hr
Fe-
HYDROX-
IDE
2 t/hr
PRECIPITATION
NEUTRALIZATION
COAGULATION
FLOCCULATION
CYANIDE
3 t/hr
SULFURIC ACID
POLYELECTROLYTE
FERROUS SULFATE
SEDIMENTATION
TANK
WATER STREAM
RECYCLE FLOW 30 t/hr
T
CLEAN
SOIL
17.5-20
t/hr
DISCHARGE
WATER
15 t/hr
SAND/SLURRY
SLUDGE
WATER
Adapted from: Breek, H.C.M., written correspondence to J. Hyman of Alliance, March 16, 1988.
-------
Appendix H
Heidemij Soil Washing Using Froth Flotation
Heidemij Uitvoering BV
afd. Milieutechniek
Veemarktkade 8 (5222 AE)
Postbus 2344
5202 CH 's-Hertogenbosch
The Netherlands
Ir. R. Haverkamp Begemann, Product Leader - Soil
Cleaning
Ing. E.G. Mulder, Product Leader - Cum-Bac,
Steam Stripping
Tel.: 011-31-73-21 50 50
Process Description
The froth flotation method of soil cleaning was
developed out of mining technology and enlarged to a
pilot-scale plant by Heidemij Uitvoering. The first
step of the process is wet-screening out the coarse
rubble fragments > 4 mm. The resulting slurry (one
part earth, three parts water), is conditioned with
cleaning agents before entering the froth flotation
tanks. The slurry has a certain dwell time in the
flotation cells, depending on the form of the
pollutants. To allow for this flexibility, Heidemij has up
to ten flotation cells which can be used in parallel.
The contaminated float is skimmed off and the slurry
is pumped to wet-scouring tanks where it receives
its final washing in clean water. The cleaned slurry is
dewatered by filtration and the soil is then usually
returned to its original site.
The water in the system is completely recycled. The
contaminated sludge is either incinerated or sent
abroad for disposal. No special water treatment
stream is necessary since it is cleaned during the
froth flotation process.
Process Limitations/Performance Data
Heidemij's froth flotation process is applicable to soils
contaminated by a number of materials by slightly
adjusting the process and using the appropriate
cleaning agents. These materials include:
• Oil products;
• Heavy metals;
• Inorganic compounds;
• Aromatic compounds;
• Polycyclic hydrocarbons;
• Chlorinated hydrocarbons; and
• Pesticides, herbicides, and fungicides.
The chemical additives used by Heidemij remain their
"trade secret."
Heidemij does not treat soils with a fine fraction (<
50 pm) over 20 percent. It is not economically
practical and the efficiency of the soil washing
process is not good enough to reach accepted
standards. Typically, the end volume of the cleaned
soil is 85 to 90 percent of the starting volume.
Results of laboratory and pilot-scale studies on a
variety of contaminants is shown in Table H-1.
Table H-1. Results of Laboratory and Pilot-Scale Studies
Using the Heidemij Froth Flotation Soil Cleaning
Method
Contaminant
Cyanide
PCAs
Oils
Heavy metals: Pb
Zn
Hg
As
Chlorinated HCs: HCH
Extractable org-CI
compounds
Pesticides
Oil, Toluene, and
benzene
Copper compounds
Lead compounds
Before (ppm)
200-1,000
19
> 1,000
1 1 ,900
6,040
67
135
276
5.3
650
3,000-18,000
10,000-20,000
500-1,000
After (average
ppm)
5
0.34
65
110
150
1.5
19
0.5
0.4
14.4
20
1,000
90
Source: "Procestechnologie, heidemij Uitvoering," brochure,
undated.
Heidemij has not had the opportunity to treat HCH
(hexachlorocyclohexane - usually pesticides) with
29
-------
Figure H-1. Two diagrams showing the Heidemij method of in situ steam stripping.
Steam Pipe
is
o
o
o
Condensor
Sketch of the Steam
Stripping Method
1
\
f
C7
Vi
[W2H
n
Out f
v_
o
u
o
H
'
L^
r
St
Ml
earn Boi
er
^
Generator
Steam Lance
Extraction Pipe
Final Clean-Up Approach
Vacuum
•^
. Steam
v ^Vacuum ^ ^
^ ^ . Steam ^
^ ^Vacuum . ^
B
v », >, «.
• » « • •
•^ • » »
R
2 00 M
,160
>160
Steam Boiler
Condensor
Section B-B
1 00 M
1 00 M
Source "Stoomstripper, Heidemij Uitvoering" brochure, undated
30
-------
Figure H-2. An artist's rendering of a typical Cum-Bac" installation by Heidemij.
Source "Cum-Bac, Heidemij Uitvoering," brochure, undated
their full-scale system, however laboratory-scale
treatment studies have been successful. Heavy
metal-contaminated soil has only been treated on a
pilot-scale by this system.
Cost
The processing cost varies from 145 Dfl to 250
Dfl/tonne ($90-155/ton), not including laboratory and
pilot-plant investigations. Heidemij's full-scale
mobile unit capital cost was 5-6 million Dfl ($2.8-
3.4 million). Their break-even point, assuming 3
days for mobilization and demobilization of the plant,
is 2,000 tonnes (2200 tons) of material per location.
At least four different permits are necessary to treat
on-site and the cost of disposing of the
contaminated residue can be as high as 350 Dfl/tonne
(about $182/ton). Heidemij is working on increasing
the volume reduction of the contaminated fraction and
decreasing the amount of chemical additives used in
order to reduce costs.
Process Status
The Heidemij mobile soil washer consists of nine
transportable skids, the heaviest one weighing 8
tonnes (9 tons). The plant occupies an area of 950
m2 (1140 sq yds) and boasts a throughput of 27
tonnes/hour (30 tons/hour).
Since permitting a mobile unit for site remediation is
so difficult in Holland, Heidemij hopes to permit their
mobile plant at the site of their headquarters in 's-
Hertogenbosch by the end of 1988.
Heidemij Steam Stripping and
Composting
Heidemij Uitvoering has several other remediation
techniques that they are beginning to market in
31
-------
Holland. One technique that has been employed with
success at several sites is in situ steam stripping.
Although it takes a few months for the ground to be
heated enough to initiate steam stripping of
contaminants, cleanup only takes a few months more.
Heidemij injects steam at 150-200°C (302-392°F)
and extracts volatile organic contaminants under
vacuum at a maximum of 0 mBar. Two diagrams of
the process are shown in Figure H-1. Data on this
technique were not available.
Heidemij is entering the biological decontamination
market with a composting technique they call Cum-
Bac®. A rendering of a typical Cum-Bac® installation
is shown in Figure H-2. Operating details and data
were not available on Cum-Bac® due to its novelty.
Heidemij Uitvoering does not currently have intentions
for licensing or exporting their remediation
technologies.
32
-------
Appendix I
High-Temperature Slagging Incineration (HTSI)
SCK/CEN, Belgium Nuclear Research Center
Waste Treatment Department
Boeretang 2000
Mol B-2400 Belgium
Mr. Rik Vanbrabant, Project Leader
Tel.: 011-32 (14) 31 68 71
Process Description
High-Temperature Slagging Incineration (HTSI) is a
volume reduction technique originally designed for
low-level radioactive wastes, but may be applied to
almost any waste type. HTSI thermally transforms
waste into a mechanically strong and chemically
stable basalt-like material in granules or bulk form.
A schematic of the HTSI process is shown in
Figure 1-1.
The first stage of the HTSI process is waste
pretreatment. Wastes are sorted, shredded to 7 cm,
and then mixed in large bins to create a homogenous
waste stream. Screw feeders convey the blended
waste to the combustion chamber, the central unit of
the HTSI.
In the combustion chamber, a burner powered by fuel
and oxygen heats the top of the wastes into a layer of
molten slag at about 1400°C (2550°F). Figure I-2
shows the progression of the molten slag film and
waste feed. The underlying waste layer serves as a
thermal barrier between the molten slag and the
refractory lining. This lower layer pyrolyzes, and the
upper molten layer undergoes oxidation. The molten
slag acts as a liquid filter for the lower layers,
absorbing most of the dust particles generated.
The slag droplets flow off the end of the refractory
bell into the granulator where they are quenched and
burst into granules. At the same time, the off-gases
travel into the off-gas treatment section of the HTSI.
The first stage of off-gas treatment is post-
combustion. In the post-combustion chamber, the
off-gases and the water vapor produced in the
granulator are completely oxidized and cooled to
900°C (1650°F). The post-combustion chamber can
be fired by either oil or combustible liquid wastes. The
off-gases are then vigorously purified by a string of
cleaning units: teflon bag filters, followed by a
scrubber unit, and ending with a series of HEPA
filters. This redundant gas cleaning system results in
a very low flue-gas organics and particulate content.
Process Limitations/Performance Data
The Belgian HTSI has not been able to process
regular quantities of hazardous waste due to its low
capacity, but experimental test runs have been
performed on the destruction of PCBs. Results of this
study are shown in Table 1-1. In the study, off-gas
concentrations for PCDDs (tetra, penta, hexa, hepta,
octa isomers) and for PCDFs (tetra, penta, hexa,
hepta, and octa isomers) were all below detection
limits. The data in the table shows a combustion
efficiency of PCBs at 957°C (1755°F) to be 99.99977
percent. The ORE for PCB is expected to be much
higher (> 99.9999 percent) because the decontam-
ination factor of the complete off-gas system is
between 104 and 106. However, this ORE has not
been proven because in Belgium destruction
efficiency and not removal efficiency has highest
priority. When capacity permits, more test runs will be
performed in the future.
Because of the high temperatures involved, HTSI can
destroy even the most stable chlorinated aromatics.
Its most severe limitation, however, is cost. Although
most of the high cost of the Belgian unit can be
attributed to safety measures to control and contain
radioactivity, this technique would still be expensive if
applied to hazardous wastes. As a result of its current
high cost, it is likely that the HTSI technology would
find applications limited to high hazard wastes such
as dioxins and PCBs. Another likely application would
be asbestos waste where concerns regarding fibrous
emissions would be minimized both during
incineration and from the solid residues.
Cost
Annualized capital cost, assuming a 10-year life for
the 60 kg/hr HTSI unit, is estimated at $600,000. The
facility at SCK/CEN runs 24 hours/day for 5
days/week and has operating costs of $160,000,
$13,000 and $16,000 a year for labor, energy and
oxygen, respectively. Maintenance costs are also
high, at $50,000 a year each for labor and materials.
33
-------
Figure 1-1 Schematic of HTSI incineration process.
Water
Cooling Water
Blow-Down Water
Source Vanbrabant, R , and N Van de Voorde "High Temperature Slagging Incineration of Hazardous Waste " 2nd International
Conference on New Frontiers for Hazardous Waste Management Proceedings Pittsburgh, PA. p 42 September 27-30,
1987
34
-------
Figure 1-2.
Purification action of the molten film in the HTSI
combustion chamber.
Table 1-1. Experimental Test Results of PCB
Incineration in the HTSI
Combustion Gases
? \>a<>
: Molten Slag Film
Waste
Source. SCK/CEN "Hazardous Waste Incineration, HAWAI
System, BWT, Belgian Wastes Technology," Brochure,
p. 14. Undated.
Mass flow rate of PCB
Air flow rate
Off-gas flow rate
% H2O in off-gases
% CO2 m off-gases
%N2 in off-gases
PCB mass flow rate in
off-gases
Residence
Combustion temperature
Lambda air factor
Off-gas O2 concentration
Combustion efficiency
248 g/h
1 222 Nm3/h
1272 Nm3/h
7.81%
8.47%
75.91%
0.55 mg/h
1 .92 sec
957 °C
1.635
7.8%
99.99977%
Source: Vanbrabant, R., and N. Van de Voorde. "High
Temperature Slagging Incineration of Hazardous
Waste." 2nd International Conference on New
Frontiers for Hazardous Waste Management
Procedings. Pittsburgh, PA. p. 40. September
27-30, 1987.
The price per year, therefore, adds up to $889,000.
At a capacity of 60 kg/hr (133 Ib/hr), treatment costs
$3.50/kg ($1.60/lb).
Process Status
The SCK/CEN HTSI has been operating full-scale
since 1981. A unit was sold to Japan in 1985 for
treating low-level radioactive waste and another
Japanese firm recently purchased a second plant to
start up in September 1990, also for that purpose. In
the United States, International Technologies of
Torrance, CA is marketing the HTSI technology under
the name Hazardous Waste Incineration system, or
HAWAI system. The HAWAI system has a slightly
modified geometry, the capabilites of using oxygen in
both the primary and secondary combustion
chambers, and a throughput of 400 kg/hr (883 Ib/hr).
The engineering details for this scaled-up system
were worked out in 1987, but a unit has not yet been
built. Currently, no HTSI facility exists for the purpose
of treating hazardous wastes.
The HAWAI unit, with a higher throughput than the
HTSI unit, would probably not meet the capacity
demanded by hazardous waste treatment facilities in
the United States. Costs would stay about the same
as HTSI, but treatment would only be practiced for
those wastes which cannot be effectively treated by
rotary kilns such as PCBs, or wastes that need
special handling such as pathological wastes.
35
-------
Appendix J
In Situ Vacuum Extraction and Air Stripping of Volatile Organic Compounds
Hannover Umwelttechnik GmbH
Impexstrasse 5
6909 Waldorf
Federal Republic of Germany
Dr. Mathias Stein, Project Leader
Tel.: 011-49 (622) 79 052
Dr. Peter Wolff, Director
Tel.: 011-49 (511) 61 40 35
Process Description
Hannover Umwelttechnik (HUT) has developed an
inexpensive and relatively effective in situ treatment
technology for vacuum extraction of volatile organic
compounds from soil vadose zones and ground
water. A diagram of a typical HUT installation is
shown in Figure J-1.
The equipment used by HUT is fairly simple and
commonly available. PVC slotted piping, 2 inches in
diameter with 0.5 mm wide slots, is placed into the
ground where the contamination is the highest as an
extraction well. A small pump, attached to the top of
the pipe via flexible plastic tubing, draws the volatile
contamination along with soil moisture through a
condensation drum for water removal. The air stream
is then passed through an activated carbon canister
to remove the volatile organic compounds. One
extraction well under ideal conditions will affect an
area up to 100 m (90 yds) in diameter. As many
pipes and pumps may be used as are necessary for
the contamination at a given site.
When the ground water is contaminated, cleanup by
air stripping is practiced in coordination with the
vacuum extraction. Compressed air is pulsed into the
aquifer through injection wells. The compressed air
strips the contaminants in the ground water and they
are then drawn to the extraction wells. A diagram of
this technique is shown in Figure J-2. The
compressed air is introduced in a pulsed manner, not
continuously, to prevent channeling or short circuiting.
Process Limitations/Performance Data
The HUT vacuum extraction technology is most
effective on sandy soils, typically reaching
background levels of 200 ppb hydrocarbons in the
soil gas. Where there is a large clay fraction, the
slotted pipes may become clogged or filled with silt.
To try to avoid these problems, HUT has devised a
double pipe extraction well. A second, larger slotted
pipe (3 inches in diameter, 1 mm slot width) is placed
concentric to the typical 2-inch extraction well, with
gravel pack in between, to act as filters to the silt and
clay particles. This extraction well configuration has
shown some success in the field.
The vacuum extraction and air stripping technologies
are only effective on volatile contaminants.
Contaminants not treated by this method include, for
example, extractable organics and PCBs. Figure J-3
shows the range and effectiveness of one extraction
well after 2 months of operation. Figure J-4 shows
the effects of vacuum extraction on hydrocarbon
concentration followed by extraction with in situ air
stripping of the ground water.
Cost
In carrying out a remediation project, HUT sells their
equipment to the customer. After the treatment is
completed, HUT may buy back the equipment at a
depreciated price. Typical treatment costs by this
method are < 10 DM/tonne (< $5 ton). The initial
investigations for a typical installation cost about
2,500 DM ($1,500). The cost of a pumping
installation is typically 2,500 DM ($1,500) also,
bringing the total price of a treatment to 5,000 DM
($3,000). If the scale of the project is large, an
automatic activated carbon filter and regenerator
made by Prouter may be leased for 7,000 DM/month
(about $4,000/month).
Process Status
A large insurance company developed HUT as a
service arm to remediate dumped spills and storage
tank leak problems at their clients' sites. The vacuum
extraction equipment developed by HUT differs from
37
-------
Figure J-1. Vacuum extraction of volatile organics in the vadose zone by HUT.
Ground Water
Table
Direction
of GW
Flow
Unaffected
Source: Hannover Umwelttechnik GmbH brochure, "Em Unternehmen Stellt Sich vor," p 1 1, October 1 987
that found in the United States market by virtue of its
simplicity and lower cost.
The key advantage to a vacuum extraction system is
that it achieves cleanup of soils with minimal waste
byproducts and is adaptable to contamination beneath
buildings. When used in combination with on-site
carbon regeneration, the by-product generation is
minimized to an even greater extent.
HUT has had over 300 vacuum extraction installations
throughout Germany. Two research projects recently
being carried out by HUT are an ozone-enhanced
biological treatment study and the in situ use of a
non-toxic surfactant to leach oils from the soil. HUT
does not yet have serious intentions for licensing their
technology abroad and they hold no patents. If they
did become interested in transferring their technology
to the United States' markets, they would probably
start a U.S. affiliate and have the necessary
equipment produced in the U.S.
38
-------
Figure J-2. Volatilization of organics in ground water by pulsing with compressed air.
c
ID
o
Ground Water
Table
Direction
of GW
Flow
is
•Us!
Injection
Well
Well
Source Hannover Umwelttechnik GmbH brochure, "Em Unternehmen Stellt Sich vor," p. 9, October 1987.
39
-------
Figure J-3. Performance and range of an HUT vacuum extraction installation.
HC
(mg/m3)
1000 r VACUUM
EXTRACTION
OF SOIL
VACUUM EXTRACTION OF
SOIL AND COMPRESSED AIR
INJECTION OF GROUND
WATER
0 100 | 200 300 Days
BEGIN COMPRESSED AIR INJECTION OF GROUND WATER
Source: Hannover Umwelttechnik GmbH brochure, "Em Unternehmen Stellt Sich vor," p. 18, October 1987.
Figure J-4. Soil gas hydrocarbon concentration over time with HUT in situ vacuum extraction and air stripping.
20
EXTRACTION WELL
WFI i
VVCL.U
AFFECTED RANGE OF
EXTRACTION WELL
INITIAL HC CONCENTRATION (mg/m3)
HC CONCENTRATION AFTER 2 MONTHS TREATMENT
Source: Hannover Umwelttechnik GmbH brochure, "Em Unternehmen Stellt Sich vor," p. 6, October 1987.
40
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Appendix K
HarbauerSoil Washing Using Low Frequency Vibration
Harbauer GmbH & Company KG
Ingenieurburo fur Umweittechnik
Bismarckstrasse 10-12
1000 Berlin 12,
Federal Republic of Germany
Mr. Werner, Managing Director
Mr. Groschel, Engineer
Tel.: 011-49 (30) 341 19 12
Ms. Margaret Brown Nels, Consultant
Tel.: 011-49 (30) 404 17 96
Process Description
The Harbauer soil washing system is currently
considered to be among the best soil washers
developed in the FRG. The heart of the unit is a low
frequency vibration step used to improve cleaning by
mechanical action. The Harbauer unit, currently in
operation at the Pintsch Oil site in Berlin, has high
operating costs due to an extensive ground
water/wastewater treatment system. A flow schematic
of the Harbauer soil washing facility is shown in
Figure K-1, with more detailed explanation that
follows.
The first step in the Harbauer soil cleaning process is
soil preparation. Particle sizes > 60 mm are
separated out of the stream by a vibrating sieve.
Gravel in the size range 10 mm < x < 60 mm is
separated out and washed with a blade washer before
the mam soil stream, x < 10 mm enters the vibration
unit.
Harbauer attributes the success of their soil cleaning
plant primarily to the vibration unit. In this unit, the soil
is subjected to oscillations using mechanical energy
to dislodge the contaminated fines from the soil
matrix. The soil is mixed with an extractant and
passed through the vibration unit by a screw
conveyor to which the vibrations are axially applied.
Because the energy and residence time can be
carefully controlled, the unit can handle a wide variety
of pollutants and soil types. After passing through the
vibration unit, the cleansed soil is then separated in
stepwise fashion with removal of particle sizes from
10 mm down to 200 pm occurring in the first step by
sedimentation; the second fraction is removed down
to 20 jam by a series of hydrocyclones; and the last
fraction is removed down to 15 pm by a flocculation
step followed by a filter belt press. Dewatering of the
sludge is done by belt press, to decrease the volume
of residues which must be landfilled.
All the contaminated effluents from soil washing are
pumped to the ground water treatment system on-
site. The ground water treatment system has five
main operations: dissolved air flotation (DAF), counter
current stripping, air stripping, sand filtration, and
adsorption (activated carbon and resin). Cleaned
water is reused or discharged into a receiving stream.
Most of Harbauer's treatment experience has been
with organic contaminations. The Harbauer facility has
treated 10,000 tonnes (11,000 tons) of soil
contaminated by organics. Heavy metals were treated
with some success, but data are not yet available. In
addition, data are being developed on gas works soil
treatment, which is also in the testing stages.
Process Limitations/Performance Data
Although specific data is not available to support it, it
seems that a combination of low frequency vibration
and other washing techniques is effective at
desorbing contaminants from the smaller particles,
allowing Harbauer to separate out a larger proportion
of reusable soil. Harbauer separates soil particles
from 15 ym and greater for a recovery rate of 95
percent. Data on the efficiency of the Harbauer soil
washing system on sandy and clayey soils polluted by
various organics is provided in Tables K-1 and K-2.
The data in Tables K-1 and K-2 show similar
organics removal efficiencies for sandy and clayey
soils. However, it is noted that higher residual
volumes will be generated by the clay soil cleaning,
adding to the treatment costs.
Limitations that Harbauer has encountered are
typically associated with the treatment process they
employ, such as the costly disposal of carbon
containing PCBs and polyaromatics, or problems with
the separation efficiency of hydrocyclones. As
previously mentioned, Harbauer has had limited
success in treating heavy metal contamination, but
additional techniques are being examined for this
purpose.
41
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Figure K-1. A flow schematic of the Harbauer soil washing installation. Adapted from: Harbauer GmbH, "Harbauer soil
cleaning process," undated.
RAW
SOIL
<60 mm
ELECTRO
MAGNET
k
W
RUBBLE
>60 mm
METALLIC OBJECTS
LOW FREQUENCY
VIBRATION UNIT
HYDROCYCLONES
WATER ADDITION
AIR STRIPPING
GRAVEL
10 mm - 60 mm
<10 mm
CONDITIONING
HCI
NaOH
SURFACTANTS
SAND FRACTIONS
0.2 mm - 10 mm
FLOCCULATION
20
FINE SAND
- 0.2 mm
<20 urn
SLUDGE
15 urn - 20 n
WASHWATER TREATMENT
FeCI3 NaOH
COUNTER CURRENT
STRIPPING
4-J
SAND
FILTRATION
GRANULAR
ACTIVATED
CARBON
SOLIDS/SLURRY
LIQUID
42
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Table K-1. Performance of the Harbauer Soil
Washing System on Sandy Soil
Pollutant
Input
Removal
Efficiency
Output (%)
Total organics
(mg/kg)
Total phenol
(mg/kg)
PAH (mg/kg)
Extractable
org-CI
compounds
(mg ClVkg)
PCB (mg/kg)
5403
115
728.4
90.3
3.2
201
7
97.5
n.d.
0.5
96.3
93.9
86.6
100
84.1
Table K-2. Performance of the Harbauer Soil
Washing System on Soils with High
Clay Content
Pollutant
Total organics
(mg/kg)
Total phenol
(mg/kg)
PAH (mg/kg)
Extractable
org-CI
compounds
(mg ClVkg)
PCB (mg/kg)
Input
4440.5
165
947.8
33.5
11.3
Output
159
22.5
91.4
n.d.
1.3
Removal
Efficiency
96.4
86.4
90.4
100
8S.3
Cost
Although the Harbauer system is considered semi-
batch, because only some of the steps are run in
batches, it has a throughput of 20 to 40 tonnes/hour
(22 to 44 tons/hour). The unit cost is 250 DM/tonne of
soil (about $136/ton, not including the cost of residue
disposal). Capital costs for the same facility today
would be in the range of 7 to 10 million DM ($4.3 to
6.1 million).
Process Status
The Harbauer soil washing facility was built in 1986
as a pilot-scale unit to remediate the Pintsch Oil
site. With all the money and effort that went into
building the facility on-site, Harbauer plans to keep
the facility on the Berlin site as a fixed unit (the
legality of this action is pending) and is already
treating soil brought in from other sites. Three other
units, which can be mobile or stationary, are currently
in the planning stages.
The ground-water treatment facility is full-scale,
treating 360 m3/hr (1,584 gpm). Unique in its large
capacity, it has been operating since 1984 and is a
NATO/CCMS Pilot Study demonstration facility.
Harbauer is carrying out experiments to study the
form and behavior of contaminants in order to
increase the removal efficiencies and the percent of
soil recovered by their soil washing operations. They
plan to license and export the technology and are
currently negotiating with several U.S. firms.
Source for both tables:Harbauer GmbH, "Harbauer Soil
Cleaning Process," undated.
43
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Appendix L
So/7 Washing Using the Oil CREP System
TBSG Industrievertretungen GmbH
Langenstrasse 52/54
2800 Bremen 1, FRG
Fred K. Gunschera, Director
Tel.: 011-49 (421) 17 63 267
Process Description
The Oil CREP Soil Washer system is among the
simplest operations seen in Europe. This system was
developed mainly for remediation of hydrocarbon and
oil contaminated sandy soils. The unit is typically
fitted with add-on particle sizing to remove fine
materials (<100 urn) when used on well-graded
materials.
Oil CREP (Cleaning Recycling Environmental
Protection) is a proprietary combination of surfactants,
solvents and aromatic hydrocarbons which cleans and
extracts oil from various media while preserving the
structure of the oil so that it may be recycled. The
recently developed Oil CREP I is a slightly less
efficient, biodegradable version of its predecessor.
After the oil is separated from the water where Oil
CREP I was used, the water is normally clean enough
to be returned to a receiving stream.
The Oil CREP System SSC-20A is a mobile soil
washer which occupies one 20-foot, 15-ton
container. It was initially built to clean sandy beaches
contaminated with oil products. A diagram of the Oil
CREP system SSC-20A is shown in Figure L-1.
Oil-contaminated sand/gravel no larger than 50 mm
is fed into the system via a hopper. Oil CREP I is
injected into the sand as it is mixed in a screw mixer.
The sand then travels to a rotating separation drum
where the oil is floated off the sand using fresh or sea
water, and spilled over into a collection tank. The
cleaned sand is reused on-site and the contents of
the oil collection tank, which includes the Oil CREP I,
is transferred to a holding tank until it can be removed
for refining or disposal.
Where necessary, TBSG often supplements their
SSC-20A unit with other equipment. Hydrocyclones,
for example, are added where a large fraction of
contaminated fines < 100pm are present in the soil.
Mixers, crushers and even flotation tanks have been
added to the system. If contaminants other than oils
are present, they will usually tend to form an emulsion
when mixed with Oil CREP I. In this case a water
treatment plant must be added.
Process Limitations/Performance Data
Although Oil CREP is meant for extracting oily
compounds. FSBG is prepared to adapt their
technology to any of a variety of situations. Where
contaminations are complex and a large fraction of
fines are present however, prices will rise and
effectiveness will decrease.
This technique is applicable to gasoline, crude oil,
mineral oil, and other oil products. The Oil CREP
System was used successfully in Spring, 1986 on a
site in Hansburg, FRG, to remove PCBs, PAHs, and
various hydrocarbons. At this site, Oil CREP was not
effective on fluoroanthene.
A diagram demonstrating the effectiveness of Oil
CREP I with respect to the quantity added based on
recent test trials is presented in Figure L-2.
Other data on the performance of the Oil CREP
System SSC 20A is shown in Tables L-1 and L-
2. It is recommended that Oil CREP I not be confused
with Oil CREP, its toxic counterpart.
Cost
Including transport, but not including disposal of
residues, cost of treatment using the Oil CREP
System is 150-190 DM/tonne ($82-109/ton).
Because of the set-up and break-down time
involved, only sites with over 3,000 m3 (3920 cu yds)
of contaminated soil can be treated economically.
For a typical installation, costs run:
• 25-30,000 DM ($15-18,000) for mobilization
and demobilization
• 10,000 DM ($6,000) for daily operations, and
• 10,000 DM ($6,000) for daily treatment of
contaminants.
45
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Figure L-1. The Oil CREP System SSC-20A.
1 Oil contaminated sand
2 Cleaning agent OIL—CREP I
3 Mixing unit
4 Separation drum
5 Washwater tub
6 Washwater reserve tank
7 Oil collection tank
8 Cleaned sand
Source Bremer Vulcan AG, et al , "Protection of the Environment, On-the-Spot Cleaning of Oil-Contaminated Sand and Soil, Oil
CREP System SSC-20A," undated
Process Status
TBSG, a shipping company, originally used Oil CREP
to clean out the tarry oil residues in their oil tankers.
Not only did Oil CREP dislodge the thick oil from the
sides of the tanks in conjunction with spraying with
high pressure water jets, but it changed its viscosity
to allow it to be pumped out.
TBSG, Bremer Vulcan AG and AEG Marine and
Offshore Systems Division, jointly developed the Oil
CREP System SSC-20A in 1984 to clean sand
contaminated by oil. It has a throughput of about 10
m3/hr (44 gpm). A prototype unit, an updated version
of the first, has an average throughput of 8 m3/hr (35
gpm). A third full-scale unit is in planning stages,
and is expected to have a throughput of 20 m3/hr (88
gpm), supposedly the theoretically highest throughput
achievable with this technique. A third washing
compound, Oil CREP II, for use with soil types other
than sand, is also being researched at this time.
TBSG is applying for licenses in Germany to sell their
SSC-20A and in the future will seek European
licenses. TBSG has not yet sought licenses in the
U.S. The washing solutions Oil CREP and Oil CREP I
are patented and can also be purchased separately
from TBSG.
46
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Figure L-2. An illustration of the residual oil contents related to Oil-CREP I injection in recent test trials.
ppm
3,000
residual
oil
content
in
relation 2 000
to
wet
sand
1,000
Source:
0.5 1.0 1.5 20VOL-%
Oil-CREP I addition related to the input
Bremer Vulcan AG, et al., "Protection of the Environment, On-the-Spot Cleaning of Oil-Contaminated Sand and Soil, Oil-
CREP System SSC-20A", undated.
Table L-1. Performance of the Oil CREP System SSC-20A
Site # 1 2
Volume in
Volume out
• Clean soil
• Sludge
• Centnfugate
Contamination
Lead (Pb)
Nickel (Ni)
PCB
Aromatics
Hydrocarbons
Extr.
Halog.-org.
PAHs
Acenapthylene
Fluorene
Phenanthrene
Anthracene
Pyrene
Benzo(a)-
anthracene
Chrysene
Benzo(b)-
fluoranthene
Benzo(k)-
fluoranthene
Benzo(b)-
pyrene
Water content
Infl.
10
1.4
10.8
<0.5
1900
39
1977
n.d.
7727
3323
6863
803
51
133
13
4.6
n.d.
13%
3.0 m3
2.5 m3
-
0.5 rn3
Effl.
5.2
2.2
0.11
<0.5
29
1.5
19
1.5
54
46
2.9
27
2
2.3
0.83
0.53
0.51
1%
5.0
40
1 0
Infl.
58.7
5.8
3.6
<05
534
4.3
286
nd.
1158
607
961
269
14
36
13
11
n.d.
15%
m3
m3
-
m3
Effl.
7.8
1.9
0.48
<0.5
94
1.5
74
8.5
132
88
14
49
4.6
4.5
19
12
11
10%
Table L-2. Performance of the Oil CREP
System SSC-20A on Four
Different Samples
Sample
Number
1
2
3
4
Infl.
Effl.
Infl.
Effl.
Infl.
Effl.
Infl.
Effl.
Water
Content
3.7
108
4.5
8.4
5.7
85
4.4
9.6
Total
Extractables
(ppm)
4238
56
8686
57
3584
81
4017
78
HCs
(ppm)
1410
19
2859
17
1603
27
1267
26
Source: TBSG Industnevertretungen GmbH,
Correspondence to J. Hyman, May 4,
1988.
Source: TBSG Industnevertretungen GmbH, Correspondence to J.
Hyman, May 4, 1988.
47
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Appendix M
Biological Remediation of Soil Using the ECO-PLUS Biosystem
Umweltschutz Nord GmbH
Bergdorfer Strasse 49
2875 Ganderkesee 1
Federal Republic of Germany
Mr. Kurt Lissner, Board of Directors
Dr. Gustav Henke, Biologist
Process Description
Umweltschutz Nord has developed an on-site or ex
situ composting technique called the ECO-PLUS
Biosystem that is currently in use on a number of
sites in Germany. They begin with a unique substrate
made of pine bark, wood chips and straw that is
composted on the site of their headquarters in
Ganderkesee. Acclimated microorganisms that have
an affinity for degrading hydrocarbons colonize in the
substrate because of hydrocarbons that occur
naturally in the pine bark.
Construction of the ECO-PLUS Biosystem begins
with a PET-lmed bed and leachate collection
system. The contaminated soil is cleaned of all wood,
plastics, stones and other large items. A large mixer
called a "Mole" is trucked on site and used to
homogenize the soil and combine the substrate with
the contaminated soil at a ratio of about 1:9. The
substrate/soil mixture is then put into the beds at 100
m3/bed (131 cu yds/bed). Dimensions of the bed are
approximately 20 m x 5 m x 1 m, and as many beds
are used on-site as necessary. The leachate is
collected and recirculated over the beds periodically
depending on relative humidity and soil moisture
conditions. Regular sampling is performed to check
oxygen and nutrient levels, for example, so that high
biodegradation rates can be maintained. When wind
and rain are a problem, the beds are protected by
planting grasses, ground covers, or clear greenhouse
enclosures.
At times, the native population of microbes are not
effective enough for timely degradation of pollutants.
In this case, Umweltschutz Nord brings their mobile
bioreactor on-site to develop supplemental biomass
by combining leachate from the beds with heat, air,
and nutrients. This enriched solution is then sprayed
over the beds. Treatment of the soil typically requires
about 12 months. Translucent bubbles can be placed
over the beds, keeping them warmer (24-35 °C,
75-95°F) and decreasing treatment time to 6
months. When employing a bubble system, a
compost filter is often used for emissions control.
The ECO-PLUS Biosystem treats soils contaminated
with hydrocarbons, primarily oils. PACs and some
organics are also treatable. For each project, a
special substrate is formulated depending on the
contaminants in the site. When a site is heavily
contaminated, the soil is separated into three
sections: low, medium, and high concentrations. The
low concentration soil is not treated; the medium
concentration soil is treated in the normal manner,
and the high concentration soil is washed prior to
normal treatment.
Where the soil cannot be economically excavated,
Umweltschutz Nord performs biorestoration in situ. In
this case bioreactors are used on-site to cultivate
the microorganisms in combination with nutrients.
This solution is then pumped into the soil and
recirculated. This technique is most effective on
sandy soils. On very sandy soils, the microbe/nutrient
solution is not applied by pumping, but placed on top
of the contaminated area and let to seep. At the time
of this writing, Umweltschutz Nord had five in situ
installations operating in the Federal Republic of
Germany.
Process Limitations/Performance Data
The ECO-PLUS Biosystem, being only effective on
biodegradable contaminants such as hydrocarbons, is
not effective on heavy metal- or PCB-polluted
soils. Another limitation is the length of time required
for treatment, relative to other remediation techniques
such as soil washing or incineration.
To improve their process, Umweltschutz Nord has
developed a type of mixer that will be used to mix and
aerate the soil in the beds. The use of this mixer, in
conjunction with a bubble, will decrease the treatment
time from 6 to as low as 3 or 4 months.
There are a total of 43 ECO-PLUS Biosystem
installations in West Germany at the time of writing.
Results from two of such projects is provided in
Tables M-1 and M-2. In these two situations, the
49
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high concentration soil was not washed, but diluted
with the low concentration soil prior to treatment. The
cleanup level set by the German government for
these two projects was at most 1 g hydrocarbon/kg
dry soil.
Table M-1. Results of an Eco-Plus Biosystem Open
Bed Installation at a Mineral Oil-
Contaminated Storage Tank Facility in
Altlast. Concentrations Shown are the
Average from 14 Beds.
Date of Sample Average mg HC/kg Dry Soil
6/86
7/1/86
10/1/86
1 2/1 6/86
3/87
8/5/87
3/88
7,000
6,911
4,240
1,380
1,000
396
145
Source: DGMK (German Scientific Society for Oil, Gas and
Coal), "Report on the Results of Biological Ex situ
Rehabilitation of Oil-Contaminated Soil." DGMK
Project No. 396-02, Hamburg, Federal Republic of
Germany, January 1988, p. 30.
Table M-2. Results of an Eco-Plus Biosystem Open
Bed Installation at the Diesel Oil-
Contaminated Department Grounds in
Wedel. Concentrations Shown are the
Average from 16 Beds.
Date of Sample Average mg HC/kg Dry Soil
6/10/86
12/18/86
7/3/87
9/22/87
13,300
9,430
5,987
4,820
Source: DGMK (German Scientific Society for Oil, Gas and
Coal), "Report on the Results of Biological Ex situ
Rehabilitation of Soil." DGMK Project No. 396-02,
Hamburg, Federal Republic of Germany, January
1988, p. 42.
Umweltschutz Nord literature claims levels less than
500 mg HC/kg soil can be easily reached within
several months, depending on conditions. The treated
soil is commonly returned to its original place, but
because of its high biological activity, could be useful
for embankments or as landfill covers.
Cost
For the two projects previously mentioned, the costs
were 144 and 187 DM/tonne, respectively ($76 and
$99/ton). These costs exclude excavation and
preparations. Umweltshutz Nord predicts total
treatment costs for ex situ biorestoration to fall in the
range 150 to 240 DM/tonne ($82 to $136/ton). In situ
treatment will cost less.
Process Status
Umweltschutz Nord is the name of the company of
scientists and engineers that performs the research
and cleanups. lAT-Biosystems is the subsidiary that
manufactures all the necessary equipment. They are
both located together at Ganderkesee. Besides the
ECO-PLUS Biosystem, Umweltschutz Nord has at
their disposal a wide variety of mobile remediation
processes including physical/chemical units such as
flotation tanks, self-actuating and continuous oil-
skimmers, and reed beds for ground-water bio-
remediation.
Since there is a German law that remediation by
recycling be selected over destructive technologies,
Umweltschutz Nord has received a great deal of
business. The company is hoping that a small partner
in the United States can be found to help them out
with contacts in the oil and environment industries. A
small consulting branch has been established in Big
Sandy, Texas for this purpose, called ENTEC,
telephone number (214) 636-4376.
•ftU.S. GOVERNMENT PRINTING OFFICE: 1988 - 548-158/87045
50
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