COMMITTEE ON
^ THE CHALLENGES OF
MODERN SOCIETY
EPA/542/R-95/006
May 1995
NATO/CCMS Pilot Study
Evaluation of Demonstrated and
Emerging Technologies for the
Treatment and Clean Up of
Contaminated Land and
Groundwater (Phase II)
i
Interim Status Report
Number 203
NORTH ATLANTIC TREATY ORGANIZATION
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NATO/CCMS Pilot Study II
NATO/CCMS Pilot Study
Evaluation of Demonstrated and Emerging
Technologies for the Treatment and Clean Up
of Contaminated Land and Groundwater
(Phase II)
interim Status Report
May 1995
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NOTICE
This report was prepared under the auspices of the North Atlantic Treaty Organization's Committee on the
Challenges of Modern Society (NATO/CCMS) as a service to the technical community by the United States Environ-
mental Protection Agency (EPA) and The Nottingham Trent University (United Kingdom). The document was
funded by EPA's Technology Innovation Office under the direction of Walter W. Kovalick, Jr. (Director), and John
Kingscott (Work Assignment Manager). Dr. Paul Bardos and Dr. Ian Martin of Nottingham Trent University
provided significant technical contributions and reviews. The report was prepared by Environmental Management
Support, Inc. of Silver Spring, Maryland, in partial fulfillment of contract 68-W2-0004. Mention of trade names or
specific applications does not imply endorsement or acceptance by the U.S. EPA. i
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NATO/CCMS Pilot Study II
CONTENTS
INTRODUCTION m
LEGEND AND NOTES iv
PILOT PROJECTS l
Trial of Air Sparging of a Petroleum (Gasoline) Contaminated Aquifer 1
Technical and Economic Aspects of In Situ Bioremediation 2
Demonstration of Thermal Gas-Phase Reduction Process 3
Field Demonstration of an In Situ Treatment for Hydrocarbon Contaminated Sites Using Wellpoints ... 4
In Situ/On Site Bioremediation of Industrial Soils Contaminated with Organic Pollutants 5
Combined Scrubber Bed/Biofilter for the Removal of Volatile Organic Compounds
from Contaminated Soil g
Integrated Treatment Technology for the Recovery of Inorganic and Organic Contaminants from Soil . . 7
Biodegradation of PAHs at Frederiksberg Gasworks g
Groundwater/Soil Remediation at a Former Manganese Sulphate Plant 9
Ozone Treatment of Contaminated Groundwater 10
Soils of Garbage Dumps of Coal Tar and Petroleum Tar Distillation Plants 11
Assessment of a Biological In Situ Remediation 12
Cleaning of Mercury-Contaminated Soil Using a Combined Washing and Distillation Process 13
Environmental Problems at Tokol Airbase and Other Former Soviet Military Bases in Hungary 14
Treatment of Creosol-Contaminated Soil 15
Modeling and Optimization of In Situ Remediation; Effects of Spatial Variability on
Predicting the Duration of Soil Flushing 16
Combined Remediation Technique Fortec® 17
Sorption/Solidification of Selected Heavy Metals and Radionuclides from Water 18
Chemical Fixation of Soils Contaminated with Organic Chemicals 19
Decontamination of Metalliferous Mine Spoil 20
CACITOX™ Soil Treatment Process '.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'.'. 21
In-Pulp Decontamination of Contaminated Soils, Sludges, and Sediments 22
Using Separation Processes from the Mineral Processing Industry for Soil Treatment 23
Demonstration of Peroxidation Systems, Inc 24
In Situ Microbial Filters 25
Phase Transfer Oxidation 26
Bioventing in the Subarctic Environment 27
In Situ Removal of Coal Tar 28
Basket Creek Surface Impoundment 29
NEWLY ACCEPTED PROJECTS 31
Bioremediation of Petrochemicals Following a Major Fire 31
Bioclogging of Aquifers for Containment and Remediation of Organic Contaminants 32
Remediation of Methyl Ethyl Ketone Contaminated Soil and Groundwater 33
Rehabilitation of a Site Contaminated by Tar Substances Using a New On-Site Technique 34
Innovative In Situ Groundwater Treatment System 35
Treatment of Polluted Soil in a Mobile Solvent Extraction Unit 35
Mobile Low Temperature Thermal Treatment Process 37
Fluidized Bed Soil Treatment Process "BORAN" 33
Slurry Decontamination Process 30
Use of White-Rot Fungi for Bioremediation of Creosote-Contaminated Soil . . . 40
Soil Washing and DCR Dehalogenation of PCB-Contaminated Soil 41
In Situ Soil Vapor Extraction Within Containment Cells
Combined with Ex Situ Bioremediation and Groundwater Treatment 42
Enhancement Techniques for Ex Situ Separation Processes
Particularly With Regard to Fine Particles 43
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NATO/CCMS Pilot Study II
Multi-Vendor Treatability Demonstration of Bioremediation Technology ., 44
Integrated Pneumatic Fracturing/Bioremediation for the In Situ Treatment of Contaminated Soil 45
GUEST PRESENTATIONS : 46
Solidification Application: Solidification of Fly Ash Samples Coming from Solid Waste Incineration Plant 46
Selection of Remedial Technologies • • ; 4^
Prediction and Optimization of the Abiotic Environment in Landfarms to Enhance Biodegradation 46
Controlled In Situ Groundwater Treatment t 47
U.S. Air Force Bioventing Initiative 47
Danish Assistance in the Remediation of Tokol Airbase • 48
NATO/CCMS FELLOWS • 49
NATIONAL CONTACTS 51
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NATO/CCMS Pilot Study II
INTRODUCTION
The Council of the North Atlantic Treaty Organization (NATO) established the Committee on the Challenges of
Modern Society (CCMS) in 1969. CCMS was charged with developing meaningful programs to share information
among countries on environmental and societal issues that complement other international endeavors and to provide
leadership in solving specific problems of the human environment. A fundamental precept of CCMS involves the
transfer of technological and scientific solutions among nations with similar environmental challenges.
The management of contaminated land and groundwater is a universal problem among industrialized countries,
requiring new and improved remedial technologies. This document provides an interim status report on the second
phase of a Pilot Study designed to share information among countries on innovative treatment technologies. The
United States is the lead country for the Pilot Study, and Germany and the Netherlands are Co-Directors. The first
phase successfully concluded in 1991, and the results were published in three volumes. 1'he second phase continues
to address field-demonstrated technologies while expanding the scope to include newly emerging technologies.
Through these pilot studies, critical technical information has been made available to participating countries and the
world community.
The first meeting of the NATO/CCMS Phase II Pilot Study on the Treatment and Cleanup of Contaminated Land
and Groundwater convened in Budapest, Hungary, on October 18-22, 1992. The second meeting was in Quebec
City, Canada, on September 12-17, 1993. The most recent meeting was in Oxford, United Kingdom, September 11-
16, 1994. Summary reports for each of these meetings are available through the Country Representative listed at
the end of this report.
Each participating nation may report on up to four active case studies in the Pilot Study at any one time. As studies
are completed, new projects may be added. At the end of the Phase II Pilot Study, a final report will be published
that provides technical documentation for all projects. Because the Phase II Pilot Studies will continue for another
two years, this interim report was prepared in order to share technical information as quickly as possible.
This report is divided into four parts. The first part contains abstracts of each of the technical case studies sanctioned
by the Pilot Study prior to September 1994. Each abstract is headed by a summary table that provides pertinent data
at a glance. Most of the studies are still in progress; those that are completed are so noted in the accompanying
abstracts. A guide to the information contained in each abstract header may be found on the next page. The
summary table on page v provides an overview of the technology types, affected media, contaminants, project status,
and sponsoring country for each case study. The second part of the report contains preliminary information on 15
projects newly accepted by the Pilot Study in September 1994. The table on page 30 provides an overview of these
projects.
Although case studies are the primary focus of the Pilot Study, two other activities also provide opportunities for
technical exchanges. The third part contains summaries of guest presentations of general interest made at Pilot Study
meetings. The fourth section of this report contains a brief description of NATO fellowships projects. These
fellowships provide only travel funds to researchers who are pursuing topics of relevance to NATO Pilot Studies.
Further information on specific projects may be obtained from the individual technical contacts (listed for each
abstract) and general information on the NATO/CCMS Pilot Study from the country representatives listed at the end
of this report.
Stephen C. James
Walter W. Kovalick, Ji;., Ph.D.
Co-Directors
in
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NATO/CCMS Pilot Study II
LEGEND AND NOTES
Project Title
i i
Location
2
Technical Contact
6
tel:
fax:
Project Status
3
Project Dates
1
Costs Documented?
9>
Contaminants
4
Technology Type ,
Media ;
8 :
Project Size
1®
Results Available?
n
1 Title of project presented at the Oxford Conference, September 1994. (The same project may have had a
different title in earlier meetings at Budapest or Quebec City.)
2 The site at which the pilot project occurred. If the project was a laboratory-scale project, the :name of the
laboratory. If no geographic specificity was indicated, the name of the Country sponsoring the study.
3 If the final report was presented at the Oxford or Quebec meetings, the status is "Final." If the project is on-
going, the status is "Interim." Projects accepted at the Oxford meeting are labelled "New."
4 Contaminant groups include: Total Petroleum Hydrocarbons/BTEX (benzene, toluene, ethylbenzene, xylene);
chlorinated volatiles; chlorinated semivolatiles (such as PCBs); nonchlorinated semivolatiles (polycyclic aromatic
hydrocarbons—PAHs); heavy metals and radionuclides.
§ Technology types include: bioremediation (in situ or ex situ); soil washing (including other physical processes);
stabilization/solidification; soil vapor extraction; pump-and-treat; photochemical. .
6 Name, affiliation, and telephone/fax numbers for the first author or other technical contact for the project.
7 Remediation/project dates, if provided.
§ Contaminated media categories include: soil/sludge/sediment; groundwater (including the saturated zone and
pore spaces); surface water; air.
SD If project costs are available in the documentation, the answer is "yes." If no costs were discussed, the answer
is "no." Costs, when given, are in the monetary units of the author.
I® The scale is provided as either "bench" (or laboratory), "pilot," or "full." Bench-scale means laboratory
modeling or testing; pilot scale means field equipment at a smaller capacity for testing purposes; full scale
means at production/commercial level. If geographic extent or contaminated volume is discussed, that number
or range is provided.
311 If a written paper is available, the answer is "yes." '
IV
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NATO/CCMS Pilot Study II — Soil and Groundwater Remediation Projects
KEY
Major Feature 0
1"jt|e Minor Feature O
Trial of Air Sparging of a Petroleum Contaminated Aquifer
Technical and Economic Aspects of In Situ Bioremediation
Demonstration of Thermal Gas-Phase Reduction Process
Field Demonstration of an In Situ Treatment Using Well Points
In Situ/On Site Bioremediation of Industrial Soils Contaminated with Organic Pollutants
Combined Scrubber Bed/Biofilter for the Removal of Volatile Organic Compounds
Integrated Treatment Technology for the Recovery of Inorganic and Organic Contaminants
Biodegradation of PAHs at Frederiksberg Gasworks
Groundwater/Soil Remediation at a Former Manganese Sulphate Plant
Ozone Treatment of Contaminated Groundwater
Soils off Garbage Dumps of Coal Tar and Petroleum Tar Distillation Plants
Assessment of a Biological In Situ Remediation
Cleaning of Mercury-Contaminated Soil Using Combined Washing and Distillation
Environmental Problems at T6kol Airbase and Other Former Soviet Bases in Hungary
Treatment of Creosol-Contaminated Soil
Modeling and Optimization of In Situ Remediation
Combined Remediation Technique Fortec®
Sorption/Solidification of Selected Heavy Metals and Radionuclides from Water
Decontamination of Metalliferous Mine Spoil
Chemical Fixation of Soils With Organic Chemicals
CACITOX™ Soil Treament Process
In-Pulp Decontamination of Contaminated Soils, Sludges, and Sediments
Using Separation Processes from the Mineral Processing Industry for Soil Treatment
In Situ Microbial Filters
phase Transfer Oxidation
Bioventing in the Subarctic Environment
In Situ Removal of Coal Tar
Basket Creek Surface Impoundment
Demonstration of Peroxidation Systems, Inc.
Technology Type
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NATO/CCMS Pilot Study II
PILOT PROJECTS
Project Title
Trial of Air Sparging of a Petroleum (Gasoline) Contaminated Aquifer
•Location
Gasoline service station
Adelaide, South Australia
Technical Contact
Ian A. Hosking
Coffey Partners Intl Pty Ltd.
North Ryde, NSW
Australia
tel: 61/2-888-7444
fax: 61/2-888-9977
Project Status
Final report (test)
Interim report (full-scale
remediation)
Project Dates
Tests: September 1993 —
April 1994
Remediation: January
1994 onward
Costs Documented?
No
Contaminants
VOCs: BTEX
Technology Type
Soil Vapor Extraction with
Air Sparging
Media
Groundwater; Interbedded clays and sands
Project Size
Pilot scale
Results Available?
Yes
While air sparging substantially increased the amount of volatile hydrocarbons that can be removed by vapor
extraction in the short term, the rate slowed dramatically within just a few days. This appears to be due to relatively
low permeability at the site, and the formation of preferential flow paths for sparged air. Future remedial efforts
should make use of lowering the water table and extracting vapor through the vadose zone rather than air sparging.
A 30-year old service station leaked gasoline into the soil as a result of faulty pipinjg. Testing found 2,100 mg/L
total hydrocarbons (THC), including an estimated 200,000 kg of BTEX contamination in the "smear zone" around
the water table. A remediation strategy involving soil vapor extraction with air sparging below the water table was
selected because it is an in situ technology, obviating the need for surface water treatment and disposal. Since air
sparging is a relatively new technology, three trials were conducted prior to full remediation. This project is the first
non-pump-and-treat technology for groundwater to be included in the NATO/CCMS Phase II Pilot Study.
The first air sparging trial consisted of three vapor extraction wells arranged in a triangle and one injection well at
the center. Vacuum levels of 15-20 kPa resulted in an air permeability of 10"7 cm2. This value correlates to a water
permeability of 10"2 cm/sec, and is on the high end of the expected range for the sandy layer above the water table.
Injecting air resulted in increased extraction of THC vapor from the extraction wells. The second test, conducted
about a month later, also involved vacuum extraction with and without air sparging. Total concentrations of extracted
HC and BTEX compounds were substantially increased (often 10-fold) by air injection. Injection of air into one
extraction well also resulted in a greater rate of HC extraction than when vacuum was maintained without air injec-
tion. The system was estimated to extract between 0.04 and 0.1 kg/hr of THC, or between 1 and 3 kg/day. However,
a third trial was conducted six months later to measure THC recovery rates as a function of time. The third trial also
monitored HC and O2 stack emissions, DO concentrations in the groundwater to assess sparging with distance,
gaseous O2 concentrations in background wells as an indication of microbial activity, groundwater levels, and power.
The short second trial and the first 48 hours of the third trial resulted in extracted air (stack) concentrations of 100-
150 ppm (and as high as 300-600 ppm) of total volatile HC. However, the relatively high extraction rates achieved
in the first two days were not sustained. A sudden decline in HC extraction concentrations after 8 hours of extraction
and about 50 hours of sparging was attributed to removal of HC from the immediate vicinity and the removal of HC
from the more permeable layers. In the third trial, injection of air down one of the extraction wells did not increase
extracted HC as it apparently did during the earlier test. The zone of influence of air sparging affects the spacing
of the sparging bores and therefore the cost. Results indicated a remediation influence of 3-9 m from the injection
well. Air sparging induces water table mounding at the injection well (noticed from 3-10 m), increasing groundwater
flow from the well. Soil layering also creates horizontal flow paths. The lack of hydrocarbons reaching extraction
wells late in the trial suggests that air followed preferred pathways that were more readily cleansed of volatile HCs,
which then acted as conduits for relatively clean injected air. Soil O2 monitoring was inadequate to quantify
microbiological activity during or after the trial. Concentrations of O2 increased from 10.5% to 19-21% during
sparging. Relatively little injected O2 was consumed by soil bacteria. The concentration of O2 in the extraction
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NATO/CCMS Pilot Study II
exhaust was only 10% at the start of sparging, and probably indicates the presence of active hydrocarbon-degrading
bacteria in the smear zone. [
Project Title
Technical and Economic Aspects of In Situ Bioremediation
Location
Austria
Technical Contact
Werner Erhart-Schippek
Abelegasse 8
1160 Vienna
Austria
tel:
fax:
Project Status
Interim Report
Project Dates
N/A
Costs Documented?
No
Contaminants
Organics
Technology Type
in situ bioremediation
Media
Soil, sediment :
Project Size
Laboratory/field scale
Results Available?
No
In situ bioremediation of contaminated sites has the advantage of not having to move the contaminated soil to the
place of treatment. Effective use of in situ bioremediation requires extensive experience in hydrogeology, chemistry
and microbiology. In Austria, the estimated number of possible old landfills is about 3500. Many of these are
former industrial plants with organic compound contaminated soil. :
The objective of this project is to discover all the limitations of in situ bioremediation starting with bench scale tests
and going on to field studies. Aspects of interest are the hydraulic, geotechnical and microbiological influences on
biodegradation. The study will be divided into 5 steps. In step one the biodegradation of mineral oil products in
five different soils will be analyzed simulating the saturated and the unsaturated zone. In step two the biodegradation
of different organic compounds in a permeable soil with differing methods of aeration will be tested.
The results of steps one and two will dictate the methods used in step three where a scale-up to reactors of up to
30 m3 volume will be used to simulate real field conditions.
i
A second objective of the study is to develop a testing procedure for application of in situ biorejnediation of
contaminated soils. In addition the costs will be evaluated as a basis for financial calculations and comparing
different variants of remediation.
It is intended that the whole project will last for three years.
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NATO/CCMS Pilot Study II
Project Title
Demonstration of Thermal Gas-Phase Reduction Process
Location
Hamilton Harbor
Technical Contact
Doug Hallett
ELI Eco Logic Intl, Inc.
143 Dennis Street
Rockwood
Ontario, NOB 2KO, Canada
tel: (519) 856-9591
fax: (519) 856-9235
Project Status
Final Report
Project Dates
Costs Documented?
No
Contaminants
Chlorinated
organics, PCBs
Technology Type
Gas-Phase Chemical
Reduction
Media
Soil/Sludge
Project Size
Pilot scale
Results Available?
Yes
This patented process involves the gas-phase reduction of organic compounds by hydrogen at elevated temperatures
to convert aqueous and oily hazardous contaminants into a hydrocarbon-rich gas phase. Soils are handled within
a thermal desorption mill (TDM), which is operated in conjunction with the reduction reactor. Chlorinated
hydrocarbons, such as polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins (dioxins) are
chemically reduced to methane and hydrogen chloride (HC1), while non-chlorinated organic contaminants, such as
polyaromatic hydrocarbons (PAHs), are reduced substantially to methane and minor amounts of other light
hydrocarbons. The HC1 produced can be recovered as acid or scrubbed out in a caustic scrubber downstream of the
process.
A pilot-scale process plant was tested for the first time at Hamilton Harbour, Ontario, in 1991. The waste processed
during these tests was harbour sediment contaminated with coal-tar at concentrations of up to 300 g/kg (dry weight).
Destruction removal efficiencies (DREs) of 99.9999% were calculated based on the total organic input and the PAHs
analyzed in the boiler stack emissions. During one test, the liquid waste input was spiked with PCBs to create a
waste with a PCB concentration of 500 mg/kg. A PCB DRE of at least 99.9999% was achieved.
A second series of pilot-scale tests was conducted in 1992 in Bay City, Michigan, as part of the U.S. EPA's SITE
program. The wastes processed included oily PCB-contaminated water, high-strength PCB oil, and PCB-
contaminated soil. Once again, DRE of 99.99% or greater were achieved. SITE Program Project Bulletins and a
Technical Evaluation Report have been published.
Following the Bay City SITE demonstration, several significant improvements were made to the thermal desorption
unit in order to increase its overall efficiency in allowing the desorption of contaminants from soils. The TDM has
achieved excellent results in lab-scale tests, with PCBs in soils and sediments being desorbed from high ppm levels
down to low ppb levels, which are orders of magnitude below disposal criteria.
A commercial-scale system (SE25) has been designed with a capacity to process 100-300 tonnes/day of contaminated
soil or sediment and 20 tonnes/day of PCB askarel fluid. One similar unit is being used in Australia for the purpose
of destroying obsolete pesticides.
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NATO/CCMS Pilot Study II
Project Title
Field Demonstration of an In Situ Treatment for Hydrocarbon Contaminated Sites Using Wellpoints
Location
Canada
Technical Contact
Arnold Ross
Directeur Technique
Serrener Consultation Inc.
855, rue Pepin, bureau 200
Sherbrooke
Quebec J1L 2P8, Canada
tot: (819)829-0101
fax: (819)829-2717
Project Status
Interim Report
Project Dates
Costs Documented?
No
Contaminants
TPH/BTEX
Technology Type •
Bioremediation (in situ)
Surfactant-enhanced flushing
Media
Soil/Sludge, Groundwater
Project Size
Field scale
Results Available?!
Yes
An in situ remedial process combining soil flushing and bioremediation will be evaluated in a field scale
demonstration project sponsored by Serrener/Varisco Consortium, the National Research Council of Canada,
Environment Canada, and the Ministry of Environment of Quebec. The process is based on a wellpoint system
developed by VARISCO SPA for the control of the water table in construction projects. The site being tested has
a very low permeability (average of 10'6 cm/sec) and is contaminated with aliphatic and BTEX hydrocarbons.
i
The proposed treatment scheme is a two-stage process. After installation of the wellpoints a surfactant/co-surfactant
solution is circulated through the contamination zone and recovered at the surface. The contaminated washings are
passed through an effluent treatment plant. After recovery of the "soluble" fraction of the organic contaminants the
wellpoints are used to inject nutrients, microorganisms (as necessary), and provide aeration for in situ bioremediation
as the second stage of site clean up. It is proposed that the aeration be provided either by the injection of hydrogen
peroxide or by pumping air through the wellpoints.
The project has been divided into four steps: laboratory scale selection of surfactants; in situ soil washing tests using
the surfactant identified in lab tests; in situ biodegradation testing of residual hydrocarbons and the contaminated
washing solution; and subsequent monitoring to verify if soils have been decontaminated.
The first step has been completed with the testing of over 50 types of surfactant and co-surfactant to establish which
pairings, and at what concentrations, were effective at extracting over 95 percent of the hydrocarbons from the con-
taminated soil. Toxicity of the surfactants to degrader organisms has yet to be reported. Analysis of on site micro-
bial activity and the identification of specific degrader organisms has been conducted. BTEX and aliphatic hydro-
carbon degraders were identified.
The second part of the project has been performed at the field scale in order to specify and optimize operating
parameters of the in situ process. The results show that surfactant use has no detrimental effect on soil and
underground water microflora. Moreover, the surfactant use has no effect on ecotoxicological parameters such as
photobacterium, phosphoreum, and algae toxicological assays. The third and fourth steps will take place in the
summer of 1995.
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NATO/CCMS Pilot Study II
Project Title
In Situ/On Site Bioremediation of Industrial Soils Contaminated with Organic Pollutants:
Elimination of Soil Toxicity with Daramend™
Location
Canada (laboratory and
various locations)
Technical Contact
Igor J. Marvan
Grace Dearborn, Inc.
Mississauga, Ontario
Canada
tel: (905)279-2222
fax: (905)279-0020
Project Status
Interim Report
Project Dates
N/A
Costs Documented?
No
Contaminants
Chlorinated phenols,
PAHs, high mol wgt
petroleum hydrocarbons
Technology Type
Bioremediation
(proprietary)
Media
Soil, sediment
Project Size
Pilot/full scale
Results Available?
Yes
The Daramend™ technology is reported in this overview to represent a major advancement in treatment of soil
contaminated with organic pollutants both in terms of reduction of contaminant concentrations as well as removal
of soil toxicity.
The Daramend bioremediation technology uses solid-phase, biodegradable organic amendments prepared to specific
particle size ranges and nutrient profiles, low-intensity tillage of the soil/sediment, and maintenance of an optimal
soil/sediment water content. Previous studies have indicated that soils containing more than 300-400 mg PCP/kg
may be too toxic for direct bioremediation, requiring preliminary treatments such as soil washing. Extensive
laboratory testing with a wide range of soils contaminated with wood treatment chemicals; has proven the Daramend
technology effective in soils containing up to 2,170 mg/kg PCP, with residual concentrations as low as 0.7 mg/kg
PCP. Since the previous report in Quebec, the emphasis has been on proving the technology at full scale.
Implementation of the Daramend technology is based upon achieving a homogeneous distribution of the organic
amendment throughout the contaminated soil. A full-scale demonstration consisted of treating 1,500 T on-site and
3,500 T in situ to a depth of 60 cm. Full-scale on-site treatment reduced chlorinated phenol concentrations from 102
ppm to 35 ppm in 35 days and to 1.63 ppm after 175 days. On-site Daramend treatment reduced total soil PAH
concentrations from an initial 619 ppm to 224 ppm after 35 days and to 79.1 ppm after 251 days. Degradation of
specific PAH compounds all achieved Canadian standards for industrial soil.
During the past two years, the Daramend technology has been applied to over 50 soils with varying physical/chemical
characteristics. Treatment times reflect the chemical and initial concentrations, but range from 90 days for heavy
oil at contaminations of over 2,000 ppm up to over 200 days for similar concentrations of PCPs and most refractory
large PAHs at 40-400 ppm. Degradation rates for total PAHs are dependent upon the degradation rates of the more
refractory (4-6 ring) PAHs. Total PAHs were reduced from 1442 mg/kg to 36 mg/kg while refractory PAHs were
reduced from 1248 mg/kg to 34 mg/kg in 209 days of Daramend™ treatment.
Three established bioassays were used to determine whether a corresponding reduction in soil toxicity was attained.
The Microtox™ toxicity test was performed on soil and soil leachate, and toxicity was reduced by two orders of
magnitude in the leachate and by a factor of about 40 in soil. The earthworm mortality test resulted in 100%
mortality within 4 days in untreated soil, and 0% mortality after 28 days in soil after treatment. Seed germination
tests resulted in 88-93% germination in treated soil after five days, compared to no germination at all for radish or
oats and 30% germination of corn after five days in the untreated soil.
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NATO/CCMS Pilot Study II
Project Title
Combined Scrubber Bed/Biofilter for the Removal of Volatile Organic Compounds
from Contaminated Soil in Venting Process ;
Location
Gasoline service station
Qudbec City
Technical Contact
Yvan Pouliot
Biogdnie, Inc.
Sainte-Foy, Quebec
Canada
tel: (418)653-4422
fax: (418)653-3583
Project Status
Interim Report
Project Dates
February - July 1994
Costs Documented?
No
Contaminants
Volatile Organic Compounds
in Off-Gases
Technology Type
Biofiltration (Ex situ)
Media
Air emissions
Project Size
Pilot/full scale
Results Available?
Yes
The bioreactor has potential as a natural process; it removes a large variety of VOCs, including high odor-removing
efficiency; ease of operation and low maintenance; and wide applicability due to specific design flexibility.
The first project report (Budapest, 1992) presented general characteristics for the proposed biopile technology in a
paper entitled "Biodegradation/Bioventing Process for the Treatment of Organic Contaminated Soil." . The second
project report (Quebec, 1993), entitled "On Site Remediation of Soil Contaminated with Transformer Oil and Diesel,"
presented two case studies under extreme conditions (soil heavily contaminated with hydrocarbon and heavy clay
soil). The current report focuses on air treatment at the end of the venting system.
During soil remediation, off-gases may contain VOCs ranging to hundreds of mg/m3. Traditional technologies
include carbon adsorption, thermal or catalytic oxidation, and wet scrubbing. Biological treatment is an attractive
alternative because of its low costs, inherent simplicity, and lack of secondary wastes. The system was field-tested
with BTEX off-gases produced at a site where in situ bioventing and air sparging were used to remediate spilled
gasoline. ;
The system consists of an air/water separator, trickling filter, and biofilter. The trickling filter housed a mixed
culture of hydrocarbon-degrading bacteria sustained solely on the volatile hydrocarbons and supplemental inorganic
nutrients (nitrogen and phosphorus). The trickle filter's irrigating water is continuously recirculated, and the gas is
bubbled through in a countercurrent flow. The biofilter was a column filled with compost equipped with a gas-
distribution system. Pollutants are adsorbed to the filter medium and degraded by indigenous microbes. No nutrient
supplementation was needed for the biofilter due to high initial levels in the compost.
The system operated under winter conditions: though ambient temperatures fell below -21°C, temperatures in the
trickling filter and biofilter were maintained at 25-40°C. Initial moisture content in the biofilter was about 60%.
Since humidity control is critical in biofilters, occasional irrigation was used, despite the water-saturation of inlet gas,
to offset the drying effect of the higher temperature due to exothermic reaction of pollutant biodegradation. The
bacteria were isolated from gasoline contaminated soils, and consisted of five predominant strains. Counts of total
colony forming units of heterotrophic bacteria did not vary greatly with time in either the trickling filter or the
biofilter. However, the numbers of hydrocarbon-degrading bacteria increased by 3 to 4 orders of magnitude during
biofilter operation and then declined as the hydrocarbon was used up.
Results over 127 days of operation showed BTEX removal of about 90%; with a residence time of less than 2
minutes the concentrations of these compounds were reduced to low or non-detectable levels. The system required
a very short start-up period, with 85% BTEX removal reported during the first week. Provincial standards of 15 kg/
day TOC is easily attained with the system. Future work will involve the optimization of system design and control
of operating conditions to substantially improve the performance. ;
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NATO/CCMS Pilot Study II
Project Title
Integrated Treatment Technology for the Recovery of Inorganic and Organic Contaminants from Soil
Location
Ataratiri site, Toronto
Longue Pointe site, Montreal
Technical Contact
Bruce Holbein
Talon Metal Technologies, Inc.
1961 Cohen
Ville St. Laurent
Quebec, H4R 2N7, Canada
tel: (514) 335-0057
fax: (514)335-8279
Project Status
Final Report
Project Dates
Costs Documented?
Yes: $100/Tonne
Contaminants
Heavy metals
PAHs, Oil/grease
(heavy organics)
Technology Type
Soil Washing with
Hydrometallurgical Extraction
Media
Soil
Project Size
32 ha (Ataratiri)
Pilot scale (1 T/hr)
Results Available?
Yes
Soils from two former industrial sites exceeded guidelines for reuse due to heavy metalis and PAHs. After treatment,
all soils were brought to within residential or industrial standards. Recovered metals \vere suitable for off-site
recycling in steel and base-metal industries, while recovered organic contaminants were low mass, highly enriched
in product, and suitable for secondary treatment. The pilot-scale tests resulted in expected full-scale, cost-effective
treatment of about 500 kT of heavy metal/PAH contaminated soils at one site and about 115 kT of lead-contaminated
soil at another site.
The integrated treatment process potentially offers a number of economic and technical advantages over separate or
sequential treatment of metals and organics, as well as utility over a wide range of contaminant and soil types. The
approach uses gravity, physical, and hydrometallurgical procedures for metal recovery (leaching and chelation absorp-
tion of leached metals) and physical/chemical procedures for organics.
Four bulk samples of 35 T each from the Ataratiri site were mechanically blended and used for continuous treatment
testing at a rate of 1 T/hr, which involved debris screening, wet scrubbing for fine particles, and gravity and magnetic
separation processes for classification. Analysis of the samples revealed unacceptably high concentrations of Pb,
Cu, Zn, Ni, Cd, As, Hg, oil/grease, and PAHs. Similar samples from the Longue Pointe site were contaminated with
lead-smelter fly ash and by lead-acid battery recycling operations. No other organic or metal contamination was
present at Longue Pointe.
Coarse and fine metals were recovered separately for iron-rich and base-metal-rich products, which enhanced
recycling potential. All treated soils met requisite standards. Between 84-86% of the metal-contaminated soil mass
was recovered for reuse. Physical/chemical recovery of water insoluble organic contaminants was reasonably
effective. The bulk of the initial contaminants could be recovered to a concentrate of relatively low mass (2-7% of
initial soil mass), highly enriched in oil/grease and PAHs. Recoveries in excess of 75% of oil/grease and 95% of
PAHs were reported. Organic decontamination might be improved by washing with surfactants to remove and
process surface organics; however, this was not tested. They currently are building a 600 tonne/day plant at the
Longue Pointe lead battery site, which has concentrations of 3,000 mg/kg Pb; 80% of the Pb is adsorbed to clay
surfaces.
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NATO/CCMS Pilot Study II
Project Title ;
Biodegradation of PAHs at Frederiksberg Gasworks •
Location
Former coal gasification plant
Copenhagen, Denmark
Technical Contact
J0rn Bo Larsen
RH&H Consultants
Virum, Denmark
tel: 45/42-85-6500
fax: 45/42-83-0207
Project Status
Interim Report
Project Dates
June 1994-Oct 1995
(field tests)
Nov 1993-Oct 1994
(microcosm tests)
Costs Documented?
No
Contaminants
PAHs
Technology Type
Biodegradation (Ex situ)
Media
Soil (sandy)
Project Size
Laboratory/Pilot scale
Results Available?
Yes
At the 1993 conference in Quebec City, the report described the bench- and initial pilot-scale experiments for
constructing an on-site bioreactor to degrade PAHs. Experiments evaluated the addition of nutrients, bark and wood
chips, compost, detergents, air, clean water, and increased temperature. Preliminary results reported last year show
10*-107 soil bacteria per gram, with potential to degrade phenanthrene, anthrathene, and pyrene.
The present report concentrated on laboratory tests designed to (1) estimate the number of natural PAH-degrading
bacteria in the soil using 14C-marked PAH compounds and (2) discuss microcosm tests of these bacteria. Inoculation
on agar plates, with PAHs, was unsatisfactory except for phenanthrene-degrading bacteria. Nevertheless, tests with
radiolabelled PAHs confirmed that a population of PAH-degrading bacteria is present in adequate concentrations.
Some success was reported by adding certain detergents to desorb PAHs from the soil into the aqueous phase and
thereby increase bioaccessibilty. Concentrations in the soil of PAH compounds were reported, ranging from <1 ppm
for naphthalene to >20 ppm for flouranthene, with total PAH concentrations of about 400 ppm.
Phase II experiments were initiated using a column experiment to determine whether structural amendments like
wood chips, compost, or aeration increases biodegradation, and a microcosm experiment to determine whether
different temperatures (15°C or 25°C) and addition of detergents increases biodegradation. The column experiment
ran for 127 days, after which no significant change in PAH content in the soil was observed. The microcosm
experiment ran for 325 days, during which there was no significant change in PAH content in the soil for the first
four months, but when detergent was added, the PAH content was generally lower after time and there was a
tendency for degradation. For the last 198 days, there was a degradation (microbial degradation or incorporation
of PAHs in the organic fraction of the soil) on 66%-74% (for Phenanthren, flouranthen, anthracen, pyren, and
benz(a)pyren. These results were the same for all treatments and for the control. It is believed that the absence of
degradation during the first four months is due to an initial inhibition of the microorganisms, which is due to the
addition of nutrient salts, resulting in high pH values in the soil.
Field testing of 10 homogenized plots (five outside and five inside) of 27-35 m3 was initiated in June 1994.
Monitoring of PAHs, dissolved gases, water, nutrients, and microbial activity will continue through October 1995.
Results will be reported at the next conference.
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NATO/CCMS Pilot Study II
Project Title
Groundwater/Soil Remediation at a Former Manganese Sulphate Plant
Location
Former Mn04 plant
Vollerup, S0nderjylland,
Denmark
Technical Contact
Karin Christiansen
Carl Bro Consultants
Glostrup, Denmark
tel: 45/43-48-6979
fax: 45/43-48-4414
Project Status
Final Report
Project Dates
N/A
Costs Documented?
No
Contaminants
Cyanide and sulphate
Technology Type
Biodegradation
(Treatability assess-
ment for various
processes)
Media
Soil and groundwater (glacial clay and sand
bounding two connected aquifers)
Project Size
Laboratory and Pilot Scale
45,000 m3 (81,000 tonnes)
Results Available?
Yes
Residues of cyanide and sulphate from a plant that converted coal gasification process wastes to MnSO4 have
contaminated the soil and groundwater. While MnSO4 contamination is not common, cyanide residues are very
common at such gasification sites. Traditional remediation (off-site incineration) was estimated to cost 8-13 million
ECU, and there are about 125 gasification sites in Denmark. Consequently a pilot-scale demonstration was initiated
to evaluate alternative remedial designs with a view to reducing costs.
Approximately 28 metric tons of cyanide and 1,140 tons of sulphate are the primary contaminants. Laboratory scale
studies included the leachability of CN and SO4 from the surface waste piles into the groundwater, the
biodegradability of CN, and the possible treatment of leachate by flocculation or UV. At pilot scale, the project
investigated the percolation of CN and SO4 from the production wastes as a function of Kh and pH and the efficacy
of treatment using membrane filtration and biodegradation. Both distillation of leachate and reverse osmosis also
were considered, but rejected as economically infeasible when ultimate disposal of concentrated brines is considered.
The SO4 concentration in the vadose zone between leachate and groundwater was a.bout 1,6000 mg/L.
The surface wastes exhibited high leachability of CN and SO4, especially at high pH (>I.O), and the leaching could
be increased by adding NaOH to further increase pH. Since the pH of the groundwater is very low (3.4), and
because cyanide will precipitate at low pH, relatively little cyanide is estimated to be in solution. The fine-particulate
dust residue from the gas cleaning process could not be leach-tested at the pilot-plant scale. Experiments to
precipitate SO4 with BaCl2 worked, but left unacceptable Ba and Cl levels as residues. Also, full-scale barium
treatment would have required an estimated 400-620 tons/year of BaCl2, a prohibitive expense. Pilot-scale biological
treatment was unproven due to the unreliability of the system over time. The costs associated with full-scale
biological treatment, including expensive and labor-intensive monitoring, did not permit further investigation.
In situ treatment was practical only if SO4 leaching was artificially accelerated, and then only in frost-free seasons.
Infiltration of neutral water would preserve groundwater conditions, but would take too long. Infiltration by NaOH
would accelerate SO4 leaching, but would precipitate iron hydroxides and otherwise add a chemical agent to the
groundwater. Ex situ (batch) treatment is estimated to take 18 years, an unrealistic limeframe. In situ treatment of
the cyanide proved infeasible during the pilot tests due to unacceptable clogging. In situ biological treatment is
predicted to take 7-10 years at pilot scale, still leaving an unacceptable residue of cyanide.
In conclusion, ex situ treatment of the SO4 production waste is infeasible due to high costs, long duration, and
redisposal of effluent. In situ treatment is infeasible due to effluent disposal problems. The scale-up from pilot to
full-scale will require significant and costly modification, as well as considerable labor to maintain the system. The
unusual pH conditions at the site, together with the conflicting responses of SO4 and cyanide to pH changes, make
the problem economically intractable. The results of the pilot test seem to recommend leaving the MnSO4 wastes
on site, covered with clean soil from other locations, together with regular groundwater monitoring. No treatment
will be contemplated as long as the SO4 concentration remains below 250 mg/L. Solute transport modeling
confirmed that the SO4 plume is not likely to expand. The 800 tons of cyanide-contaminated waste will be excavated
and incinerated.
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NATO/CCMS Pilot Study II
Project Title
Ozone Treatment of Contaminated Groundwater
Location
Abandoned limestone quarry
Vaucelles, France
Technical Contact
Pascale Antonus
SAFEGE Inge"niers
Nanterre, France
tol: 33/14614-7260
fax: 33/14617-7253
Project Status
Final Report
Project Dates
1991-1994
Costs Documented?
Yes
Contaminants
Chlorinated solvents, esters,
phenols, and aromatic
hydrocarbons
Technology Type
O3/UV degradation
after Biological
pretreatment
Media
Groundwater
Project Size
Full scale
Results Available?
Yes
Biological pretreatment degrades contaminants into forms that can be treated more effectively by photochemical
oxidation, thus optimizing the cost and performance of the remediation. i
From 1963 to 1972 indeterminate chemical wastes were dumped into an abandoned limestone quarry. In 1980, con-
taminated groundwater and resulting bad odors were noticed from water percolating out of a natural seep at the base
of a 20 m limestone hill down-gradient from the quarry, near the Autumn River valley. Under the limestone is a
layer of fine sand underlain by a thick impermeable clay. The sand layer is a drinking water aquifer. The
contamination plume has penetrated the limestone and sand to a depth of 40 m beneath the quarry. Clean up was
initiated in 1991 when the French Energy and Environment Agency assumed responsibility for the project. The
annual flow of the 20m-thick contaminated plume is estimated to be 50-80,000 m3, or 25 mVhr. Over 20 toxic
chemicals were identified in the groundwater, including chlorinated and nonchlorinated solvents, alcohols, petroleum
hydrocarbons, aliphatics and aromatics, and volatiles. Ethanol, phenols, chlorinated solvents, BTEX, acetone, and
several aliphatic hydrocarbons were noted in concentrations exceeding milligrams per liter. Chemical oxygen demand
was 250 mg/1; total organic carbon was 60 mg/1; and AOX was 5.5 mg/1.
A 600 m long, 6 m deep drainage trench was constructed at the base of the cliff to intercept the groundwater flow.
Contaminated water was pumped to an aeration reactor, where organics were microbially degraded. Activated sludge
was separated from the treated water using a membrane filter, resulting in 5 times greater biomass retention and 5
times lower sludge production. Concentrated chlorinated aliphatic and aromatic contaminants are then oxidized to
the point where they can be naturally biodegraded.
During the pilot testing, experiments were conducted with and without biological pretreatment, and with oxidation
with ozone, peroxide, and UV in various combinations. After pretreatment and ozonation, significant reduction in
chlorinated hydrocarbons—to below detection limits—was reported. Concentrations of COD were 239 ppm in the raw
water, reducing to 28 ppm with ozonation alone, and undetectable after pretreatment and ozonation. Dissolved
constituents were reduced by 80-85%, and 100% of VOCs were eliminated. Estimated costs for reducing VOCs to
acceptable drinking water limits were FF15 million (capital cost) plus FF23.7 million annually. Meeting acceptable
surface water discharge levels would cost about FF10 million initially, with an annual cost of FF1.7 million. Ozone
consumption was higher in an O3/H2O2 system than in O3/UV, but the results were the same.
10
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NATO/CCMS Pilot Study II
Project Title
Soils of Garbage Dumps of Coal Tar and Petroleum Tar Distillation Plants
Location
France
Technical Contact
Jean Pierre Cathala
tel:
fax:
Project Status
Interim Report
Project Dates
Costs Documented?
No
Contaminants
PAHs
Technology Type
Bioremediation
with oxidation
pretreatment
Media
Soil
Project Size
Pilot scale
Results Available?
Yes
Dump sites of former coal tar and petroleum distillation plants in France are characterized by high concentrations
of total hydrocarbons (2200 mg/kg in soil and 4800 mg/kg in settling ponds), phenols (3 arid 10 mg/kg), PAHs (1500
and 850 mg/kg), and cyanides (10 and 300 mg/kg). The cyanides are bound to the sediment. Research was
conducted to identify PAH-degrading bacteria, evaluating PAH bioremediation practicability, and evaluating whether
oxidizing pretreatment will increase bioremediation of PAHs.
Five fungi and nine bacteria were tested on PAHs in a recirculating water bioreactor. The test piles were constantly
mixed and aerated. Amendments of straw (50-100 kg/ton), sawdust (20-50 kg/ton for sludges only), and 50% clean
soil (for sludge only) were evaluated. Inorganic nutrients were provided in 2-5 kg/ton of Max Bac, a proprietary
timed-release nutrient claimed to be specially formulated to speed the microbial degradation of hydrocarbons. Four
bacteria but no fungi showed PAH degradation after a 2 month trial. During the pilot testing, it became apparent
that the high tar concentrations in the soil made it difficult to get full mixing and therefore limited bioaccessibilty.
Similarly, it was speculated that heavy clay soils might inhibit the process unless the piles could be thoroughly
mixed. Nevertheless, PAH degradation of 75% (800 ppm to 200 ppm) was achieved in 12 months, during which
time total hydrocarbons were reduced from 1,275 ppm to about 220 ppm. Phenols were quickly degraded (within
7 weeks they were reduced by 75%), while cyanides were much slower (2-3 months for 50% destruction). Three
oxidizing pretreatments were tested by mixing them in as the on-site piles were constructed: hydrogen peroxide,
sodium hypochlorite, and ozone.
In summary, biological seeding was necessary after initial sterilization; the rate of oxidation must be high in order
to see positive results with PAHs; bioremediation rate is increased with oxidation; and an oxidizing catalyzer such
as ferrous sulphide reduces the amount of nutrients necessary. In 19 weeks, 1000 ppm PAHs was reduced to 50 ppm
with pretreatment, hydrogen peroxide, and a ferrous sulphide catalyzer.
11
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NATO/CCMS Pilot Study II
Project Title
Assessment of a Biological In Situ Remediation
Location
Former coal gasification plant
Karlsruhe, Eastern Germany
Technical Contact
Hilke Wiirdemann
Univ. Fridericiana Karlsruhe,
Germany
tel: 49/721-608-3290
fax: 49/721-696-096
Project Status
Final Report
Project Dates
1991-1994
Costs Documented?
No
Contaminants
PAHs
Technology Type
Bioremediation (In
Situ)
Media
Groundwater (sandy gravelly subsoils)
Project Size
Pilot scale: 9 x 15 m, 17 m
deep
Report Available?
Yes
Below a former gasworks site in Karlsruhe, PAH contamination of a gravel/sand aquifer extends to a' depth of 10
m, with the zone of maximum contamination lying between 5 and 7 m. In this zone 14,000 mg/kg of PAHs have
been detected in the <2 mm fine soil fraction. The contaminated area was sealed with walls extending 17 m into
an impervious clay underlayer. The water table in the confined zone was lowered, and an air venting system
installed; the horizontal permeability exceeded the vertical permeability. Oxygenation of the pore water was
continuous from the injected air, and continuous irrigation from the surface provided moisture and inorganic nutrients
to the microorganisms. Flushing water was warmed and enriched with nutrients. Periodically, the soil was flushed
with large volumes of water to measure the remaining concentration of contaminants and soil gases.
Core sampling was conducted to determine the degree of contamination. Samples of 16 PAHs and 2 methylnaptha-
lenes were evaluated gravimetrically, by infrared spectroscopy, and by gas chromatography. Apart from the
unevenness of contaminant distribution, chemical quantification was highly dependent upon the method of analysis.
Gravimetric determination of lipophilic organics resulted in total contamination of 5,000 kg, IR measurements showed
only 2,000 kg, while GC analysis of total PAHs was 600 kg. Lipophilic organics turned out to be the most suitable
parameter to quantify the total contaminant load.
Unfortunately, engineering difficulties and the natural heterogeneity of the substrate made it impossible to extract
meaningful samples from reboring the original cores. Consequently, the biodegradation process was monitored after
a year by extracting frozen, undisturbed cores from within the treated areas as well as from the surrounding
(contaminated but untreated) areas. Since the composition of PAH is nearly constant, heavy PAHs (>4 rings) can
be used to measure degradation because this fraction is in nearly constant proportion to the original total contaminant
load. Monitoring produced a relative increase in PAHs that indicated a degradation of 54% in highly contaminated
samples. Laboratory experiments with undisturbed soil samples showed significantly higher degradation. Depending
upon the kind of measurement used, two years of biodegradation showed 70-90% destruction of PAHs. Monitoring
of CO2 and O2 over three years enabled a calculation of the soil respiration rate, which is a measure of the biological
degradation rate. The data showed that 7,700 kg of O2 were consumed and 7,600 kg of CO2 were produced,
indicating decomposition of about 2,400 kg of organic material. Soil aeration and nutrient addition greatly increased
degradation rates. The large O2 demand demonstrates the necessity of lowering the water table for aeration by
venting.
The extreme heterogeneity of the subsoil greatly complicated the determination of bioremediation efficiency. The
main limiting factor seemed to be the contaminant bioavailability in the aquifer. During the three-year project,
chemical oxygen demand decreased by 83%, dissolved organic carbon decreased by 76%, and the overall decrease
of PAHs in the flushing water concentration was 97%. The bioluminescence test for toxicity indicated 98%
detoxification. Overall, about 54% of the soil PAHs was degraded after 2!/2 years. Thus, while a lot of PAHs
remained in the soil, its toxicity was considerably reduced.
12
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NATO/CCMS Pilot Study II
Project Title
Cleaning of Mercury-Contaminated Soil Using a Combined Washing and Distillation Process
Location
Marktredwitz, Germany
Technical Contact
Winfried Groschel
Fa. Harbauer & Co.
Berlin, Germany
tel: 37/30061-0
fax: 37/30061-230
Project Status
Interim Report
Project Dates
November 1991 -
July 1994
Costs Documented?
No
Contaminants
Mercury
Technology Type
Thermal Desorption
(Vacuum Distillation)
Media
Soil
Project Size
Full scale
Report Available?
Yes
This project demonstrated the first full-scale application of vacuum distillation technology, which is proven effective
for soils contaminated with volatile and semi-volatile substances like tar fractions, oil, and mercury. The technology
can be used in conjunction with soil washing for soils or fractions with high silt/clay concentrations or with very high
contaminant loads. In this application, mercury-contaminated soils excavated from a former chemical plant were
successfully reduced from peaks of 1900 mg/kg to below the target level of 50 mg/kg, frequently reaching 20 mg/kg.
So far, 15,000 tons of contaminated soil have been treated successfully, with an average throughput of 150 tons/day.
Soil washing is used to produce a concentrated fraction in the size between 100 urn and 8 mm, and then vacuum
distillation removes the contaminants. Precipitation sludge is disposed separately, and used ion-exchange resin is
recycled off-site. Thermal desorption at 100°C is followed by a vacuum distillation process in which the soil is
heated in a rotating drum to 350-450°C under reduced pressure (50-150 hPa). Mercury is volatilized and recovered
by recondensation. The use of reduced pressure (rather than higher temperatures) permits significantly lower energy
costs and only 1/20 to 1/30 of the flow of process treatment gas that is considered normal for incineration. Since
vacuum distillation permits a low O2 environment, secondary oxidation does not occur and dangerous organic
residues like dioxin cannot be formed. Treated soil with residual concentrations still greater than 50 mg/kg are
passed again through the treatment process.
Soil exiting the dryer has a residual moisture content of under 1%. Off-gas from the; drying step is treated in a vent
condenser. Treated soil is remixed with coarse materials and disposed of in a landfill. Tests have proven that, in
addition to mercury, volatile and semi-volatile contaminants such as BTEX, solvents, TPHs, PAHs, and phenols can
be successfully treated.
13
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NATO/CCMS Pilot Study II
Project Title
Environmental Problems at Tokol Airbase and Other Former Soviet Military Bases in Hungary
Location
T6k81 airbase near Budapest
and other sites throughout
Hungary
Technical Contact
Robert Reiniger
National Authority for the
Environment
Budapest, Hungary
tel: 36/1-201-1725
fax: 36/1-201-4282
Project Status
Interim Report
Project Dates
September 1990 — June
1991 (assessment)
1991 onward
(remediation)
Costs Documented?
Yes: US$600 million
Contaminants
Petroleum hydrocarbons
Technology Type
Pump-and-Treat
Media '
Soil, groundwater :
i
Project Size
3 x 106 m3 soil
106 m3 groundwater
6,000 m3 free HC in GW
Report Available?
Yes (Tokol Airbase
remediation report by
Danish EPA also
available)
Following the final pullout of former Soviet armies from Hungary in 1990, the Hungarian Ministry for Environment
conducted an environmental assessment and damage survey following a method acceptable to both the Hungarian
and Soviet governments. There were 171 garrisons, 340 settlements, 6,000 major buildings, and 46,000 ha of land
in the survey. Forty percent of the damage comprises soil and groundwater contaminated with hydrocarbons and
heavy metals. The most polluted are six military airfields contaminated with jet fuels and fuel oils. Because of time
and funding constraints, work was begun in 1991 at the 20 most-polluted bases, with an objective to contain the
pollution. By the end of 1993, full remediation was accomplished at 8 sites, while the remaining 12 major sites were
completed in 1994. The goals of the 1993-94 assessment was to identify those remaining sites that require
remediation and determine those sites where only monitoring is necessary.
T6k6l airbase was one of the principal sites that needed prompt remediation. Located just 600 m from the Danube
River, it overlies an aquifer supplying about 5% of the municipal water for Hasztelek. The water table is 4 to 5 m,
and the aquifer is a Pleistocene sand/gravel layer 10 to 15m thick, underlain by impermeable clay. Contamination
from the airfield is migrating towards the Hasztelek wellfields and will reach it within 20 years.
Remediation atTQkol was accomplished in phases between August 1991 and June 1993. Free product was separated
from contaminated groundwater by depressing the water table to speed flow of groundwater to extraction wells,
pumping, and on-site water/oil separation.
Recovered free product amounting to 224,000 liters and about 700,000 liters of jet fuel were recovered from 279,000
m3 of pumped groundwater. Remediation at Tokol was accomplished in cooperation with the Danish Agency of
Environmental Protection. A technical report by the Danish EPA is also available (see page 48).
14
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NATO/CCMS Pilot Study II
Project Title
Treatment of Creosol-Contaminated Soil
Location
Former wood impregnation
plant, Lillestr0m, Norway
Country Representative
James Berg
Aquateam
Oslo, Norway
tel: 47/22-67-9310
fax: 47/22-67-2012
Project Status
Final Report
Project Dates
1992-1994
Costs Documented?
Yes
Contaminants
PAHs (Creosote)
Technology Type
Soil Washing and Ex
Situ Bioslurry Reactor
Media
Soil/Sludge
Project Size
Pilot scale
Report Available?
Yes
A wetland is receiving dense non-aqueous-phase liquids (DNAPLs) from a nearby abandoned wood-treatment plant.
No human health risk exists, only ecological. The objective of this project was to evaluate soil washing of creosote-
contaminated soil followed by bioslurry treatment of the PAH-containing sludge at pilot scale. The pilot plant
included a 1 tonne/hr washing plant and a 454 liter bioslurry reactor. Soils from the site were screened to <2 cm
because particle size distribution is very important to soil washing effectiveness. Six different soils were tested,
comprising sand, silt, clay, and sawdust/sand. Water temperature, pH, foamers, and surfactants were evaluated. A
companion composting test did not work well due to clumping because of high clay content.
Soil washing results indicated that cationic collectors combined with a foamer were most effective, exhibiting 90-95%
PAH removal from sandy soils and 20-90% removal from clay soils. Raising water temperature or pH had no
significant effect.
The technical feasibility of soil washing was proven at pilot scale, resulting in up to 97% PAH removal and 40-50%
volume reduction. The slurry biotreatment used indigenous microbacteria populations and inorganic nutrient amend-
ments and was reported to be 98% effective after 8 days. A Microtox 15-minute bioassay showed a 10-fold decrease
in toxicity after treatment.
Three areas exhibited PAH concentrations above 200 mg/kg. Treatment options at full scale include in situ impreg-
nation, excavation and ex situ biotreatment sediments, excavation of landfill soils followed by soil washing/
biotreatment, and just monitoring. Full excavation and treatment will involve 25,000 m3 and would cost about
US$6.3 million. In situ biotreatment and limited excavation would entail 8,000 m3 at a cost of US$3.5 million, and
covering and monitoring at two separate sites would cost about US$1-million.
Process costs for excavation, sorting, and backfilling were demonstrated at about US$160/m3; washing at US$300/m3;
biological treatment at US$260/m3; and pumping-and-treating at about US$530/nn3 (although the pump-and-treat
estimate is more uncertain since it includes the removal of the free phase and air injection to increase pumping rates).
15
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NATO/CCMS Pilot Study II
Project Title
Modeling and Optimization of In Situ Remediation; Effects of Spatial Variability on
Predicting the Duration of Soil Flushing, Soil Vapor Extraction, and Bioremediation
Location
The Netherlands
Technical Contact
Han de Wit
TAUW Milieu BV
P.O. Box 133
7400 AL Deventer
The Netherlands
tel: 31/57-009-9911
fax: 31/57-009-9666
Project Status
Final Report
Project Dates
Costs Documented?
Not applicable
Contaminants
Technology Type
Soil Flushing (in situ)
Media
Soil/Sludge, Groundwater, Soil Vapor
Project Size
Modeling study
Results Available?
Yes
The goal of this project is to investigate the applicability of simplified and mechanistic models used during soil
remediation. The mechanistic model being used by the project is the ECOSTAT model, a chemical equilibrium
model that is being modified for bioventing. In order to study the applicability of this model, the project compares
prior predictions of the remediation efficiency with results obtained in full-scale soil venting remediations.
In order to design and evaluate in situ soil remediation techniques, tools are needed for modeling subsurface physical,
chemical, and biological processes. However, available information for conducting soil investigations is limited, and
only rough estimates of remediation timeframes, based on average value, chemical equilibrium, and first- or zero-
order of decay, can be made. :
Decreasing soil contaminant concentrations are often predicted using geohydrological flow patterns in the subsurface.
In practice, however, these predictions are found to be too optimistic. For example, after a rapid contaminant
concentration decrease, the rate of remediation slows down and eventually stagnates, resulting in a remediation
timeframe that often is longer than-originally predicted. Sometimes this difference is small and can be accounted
for using uncertainty factors; other times, the difference is large, resulting in a much longer soil remediation
timeframe. Stagnation implies that some fraction of contaminants is not available for leaching, volatilization, or
biodegradation. A number of factors may contribute to this, including non-linear sorption, non-equilibrium kinetics,
or spatial variability in hydrology or chemistry.
The objective of this project is to develop a process that combines in situ remediation experience with the
fundamental knowledge of chemical and biochemical processes in order to develop a process to more effectively
determine soil remediation time frames. Predictions can be considerably improved using detailed soil mapping
processes and conducting experiments with the contaminated soil. However, these processes can be very time-
consuming and expensive. As an alternative, this project proposes developing a "tailor made" site-specific soil
investigation strategy that is able to identify the parameters that determine most of the uncertainty in the prediction.
This project focuses primarily on the investigation and description of non-equilibrium phenomenon observed by full-
scale vapor extractions and remediations.
16
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NATO/CCMS Pilot Study II
Project Title
Combined Remediation Technique Fortec®
Location
The Netherlands
Technical Contact
Jan Bovendeur
Heidemij Realisatie
Waalwijk, The Netherlands
tel: 31/4160-44044
fax: 31/4160-44080
Project Status
Interim Report
Project Dates
Costs Documented?
No
Contaminants
Organics
Technology Type
Combined hydraulic separa-
tion, photochemical
treatment, and ex. situ
bioremediation
Media
Soil/Sludge
Project Size
Bench scale
Pilot Scale
Report Available?
Yes
Promising results were reported for the elimination of mineral oil and PAHs using the combined washing/UV-H2O2
pretreatment/bioslurry process. However, the process requires further refinement for persistent xenobiotics. Success
with the combined process requires detailed characterization of the contaminant distribution and soil, but allows
customized remedial designs to take advantage of the positive aspects of the component techniques.
Hydraulic (hydrocyclone) separation, photochemical treatment, and bioremediation each exhibit strengths and
weaknesses. The goal of this demonstration is to combine the separate technologies into a treatment train to take
advantage of the strengths of each. Hydrocyclone separation is used to concentrate specific contaminants in selected
soil fractions, UV7H2O2 pretreatment is used to transform non-biodegradable contaminants into biodegradable
fragments (rather than to break down persistent organics), and'bioremediation is; used for the final destruction of
organic compounds or residues. The goal is to produce clean soil, with no toxic residue, in a reduced time. The
combined remediation process is called "Fast Organic Removal Technology," or "Fortec®."
Testing was done with UV/H2O2 pretreatment followed by biodegradation of mineral oil and PAHs. Biodegradation
of mineral oil was very fast (5,000 ppm mineral oil was reduced to <100 ppmi in 3 to 8 days). There was no
significant effect of photochemical treatment, as it was masked by the high initial biodegradation rate. No significant
volatilization occurred during aeration. PAHs had a relatively short treatment period (30 ppm reduced to 2-4 ppm
in 15 days). UV/H2O2 pretreatment was indispensable, however, for the recalcitrant PAHs. The PAH availability
to the UV/H2O2 pretreatment appeared to be the rate-limiting factor. However, poor mass balances were obtained
for PAHs, indicating the technique needs further refinement. A laboratory trial with the pesticide p-hexafluorohexane
(Lindane) did not show any degradation, its chemical stability apparently too high for photochemical breakdown.
Because high-molecular-weight PAHs exhibit slow biodegradation, further slowed by limited bioavailability due to
adsorption to soil organics, an experiment was tried to increase bioavailability by trV7E[2O2 destruction of the organic
matrix. The experiment was successful, with the pretreated sample exhibiting 63% destruction, compared to 23%
destruction of non-pretreated PAHs over 12 days. A full-scale demonstration plant will be constructed for further
pilot testing.
17
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NATO/CCMS Pilot Study II
Project Title ;
Sorption/Solidification of Selected Heavy Metals and Radionuclides from Water
Location
Turkey
Country Representative
Re§at Apak
Istanbul University
Istanbul, Turkey
tal: 90/1-5911-996
fax: 90/1-5911-997
Project Status
Interim Report
Project Dates
N/A
Costs Documented?
No
Contaminants
Heavy metals and
radionuclides
Technology Type
Stabilization/Solidification
(of adsorbents)
Media
Water
Project Size
Bench scale
Report Available?
Yes
Laboratory experiments were designed to test the removal of heavy metals (Hg, Cd, Cu, Pb) and radionuclides (137Cs
and ^Sr) from water by stabilizing them in bauxite wastes and coal fly ashes acting as adsorbents to prevent
leaching. Adsorbents were red muds from aluminum plants containing mineral oxides of aluminum, silicate, and
iron; and coal fly ash containing oxides of aluminum, calcium, silica, iron, potassium, sodium, and magnesium. Both
materials were strongly alkaline when leached with water, so they were first washed with weak warm HC1 and baked
dry. Washing removed about 40% of the initial fly ash by weight. Reducing the alkalinity of the red muds and fly
ash was important to meet U.S. EPA alkalinity regulations.
Various concentrations of metal ions were tested with the adsorbents in various raw and treated forms. Stability was
tested by desorption attempts at low pH (4.5) in CO2-saturated solutions and in neutral buffered NaHCO3. Batch
adsorption experiments resulted in very high values of absorption (>99.9%), and the experiments will be retried using
higher metal ratios. The order of adsorption efficiency for the metals was Hg » Cu > Cd > Pb. Since all tests
showed only a few percent leaching efficiencies, the adsorption was essentially irreversible, even in changing aqueous
conditions of pH and ionic strengths. Although the radionuclides were relatively insensitive to acid pre-treatment
of the adsorbents, combined acid and heat treatment was beneficial for I37Cs adsorption and detrimental for 9l)Sr
adsorption, probably due to the change of sorption made after this treatment.
Desorption coefficients for the radionuclides exhibited significant differences than for their adsorption coefficients,
possibly due to irreversible fixation during adsorption. However, data were reported showing radionuclide desorption
of only a few percent, at most. ^'Sr adsorption is exothermic and essentially irreversible, and both the fly ash and
red muds exhibited strong affinities. Both l37Ce and '"Sr adsorption are affected by inert electrolytes. Radiostrontium
adsorption generally increases with pH, while radiocesium adsorption is maximal around the neutral region.
While stabilization tests were conducted on the fly ash and red muds as well as on the adsorbents after they were
loaded with contaminating metals, only the results of the unloaded materials were reported. Solidification was
accomplished in prepared cement, standard sand, and carefully measured water. Red muds and fly ash were added
to the cement mixture. In concentrations below 20%, the compressive and shear strengths of the doped concrete
were not significantly different from the control concrete. However, there is a critical weight percentage of 10-20%
additives above which the strength declines dramatically.
18
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NATO/CCMS Pilot Study II
Project Title
Chemical Fixation of Soils Contaminated with Organic Chemicals
Location
United Kingdom
Technical Contact
Mr. Neil McLeod
Envirotreat Limited
226 Cot Lane
Kingswinford
West Midlands UK
tel: 44/384-288-876
fax: 44/384-288-876
Project Status
Interim Report
Project Dates
Costs Documented?
No
Contaminants
Organic and
inorganic
Technology Type
Solidification/Stabilization
Media
Soil/Sludge
Project Size
Lab scale
Pilot scale
Results Available?
No
The application of traditional solidification/stabilization techniques such as cememtitious and pozzolanic materials,
for the treatment of soils polluted with organic contaminants, has been limited by reported detrimental effects on
cement hydration, structural formation, and contaminant stabilization. The technology under development, an
advanced stabilization/solidification process, aims to overcome these limitations for the treatment of soils
contaminated with stable and recalcitrant organic waste materials.
The process is based on the use of modified organophillic clays with specially intercalated additives. Commercial
organoclays are typically quaternary ammonium salt substituted clays e.g. montrnorillonite. Such minerals possess
a combination of cation exchange, intercalation and swelling properties which make them unique. Pillared clays have
been developed with the ability to withstand excessive dehydration without loss of stability. The intercalated "pillars"
act as molecular props creating a two-dimensional porous interlayer structure which allows larger organic molecules
such as PAHs to be accommodated. Examples of pillaring agents include transition metal complexes, heteropoly
acids/polymers and organometallic cations. Clays substituted with metallic cations; such as Fe3+, A13+, and Cu2+ create
a variety of reactive sites for the chemical fixation of organic contaminants. By selective use of clays and
intercalation of appropriate quaternary ammonium ions with relatively low cost pillaring agents and reactants
(principally Fe/Al compounds), a highly efficient and multifunctional treatment media may be produced which can
be applied on a cost-effective basis.
Once the clay is added to the contaminated soil, the reactive properties of the day will ensure that organic
contaminants are chemically bound to the clay matrix. The immobilized contaminated clay can then be solidified
by conventional cement hydration techniques using a mixture of Ordinary Portland Cement and pozzolan. An
important consideration of the stabilization/solidification process is to ensure a homogeneous mix of the contaminated
soil and chemical additives. The application of the technology as both an in situ and an ex situ process is being
investigated within the research program.
The first phase of the project is supported by the U.K. Department of the Environment through the U.K. Govern-
ment's Environmental Technology Innovation Scheme (ETIS). The technology evaluation program will comprise
a series of chemical leachability and physical property/permeability testing procedures. Special instrumentation
techniques including Fourier Transform Infra Red (FTIR) will be used to demonstrate chemical bonding of specified
organics to the clay matrix and/or the reactive clay pillar structures. A full-scale trial will be carried out in the
second phase of the project.
19
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NATO/CCMS Pilot Study II
Project Title
Decontamination of Metalliferous Mine Spoil
Location
United Kingdom
Technical Contact
John Palmer
Richard, Moorehead and Laing Ltd
55 Well Street
Ruthin
Clwyd, LL15 1AF
United Kingdom
tel: 44/824-704-366
fax: 44/824-705-450
Project Status
Final report
Project Dates
1990-1993
Costs Documented?
No
Contaminants
Metals (lead and zinc)
Technology Type
Soil washing
Media
Mine spoil
Project Size
Lab scale
Pilot scale
Results Available?
Yes
Laboratory scale studies of mineral processing techniques were conducted on lead and zinc contaminated spoils from
abandoned mines in mid and north Wales. These techniques, used to extract metal-rich ores from less valuable waste
material, may be applicable to the removal of contaminants from metalliferous spoil materials to reduce the
environmental impact of such spoil. The evaluation of techniques represented the first phase of a two-part study to
identify the promising treatment options for a detailed examination in the second phase of the study. i
Characterization of the mine spoil was carried out to determine the mineralogy of contaminating particles and the
distribution of contamination according to particle size. Concentrations of lead and zinc in the whole spoil samples
were up to 20% and 15% by weight respectively. Lead was observed to concentrate in the finer particle sizes of
the spoil. Weathered spoil samples contained a much higher content of oxide, carbonate, and sulphate mineralogy
than fresh spoil samples which contained sulphide. i
Mineral processing techniques exploit physical and chemical differences between contaminated and uncontaminated
particles. Differences in particle density and surface chemistry for the separation of spoil particles were evaluated
using dense media (so called "sink and float") and froth flotation tests. A Multi-Gravity Separator (MGS) was used
to further evaluate density separation at pilot scale. Laboratory-based density separation resulted in consistently
reduced metal concentrations (<2% by weight) in the lighter spoil fractions representing over 90% of the total sample
weight. The heavier concentrate contained up to 32% lead and 5% zinc by weight. Although significantly cleaner
than original spoil these levels still greatly exceeded U.K. soil guidelines. The pilot scale MGS treatment produced
similar results on the <0.5 mm fraction of spoil. The effectiveness of the froth flotation trials depended critically
upon the mineralogy of the spoil. Unweathered material, rich in sulfides, resulted in better segregation of
contaminants into the concentrate.
Leaching of metal contaminants from the spoil by a variety of chemical agents such as sulfuric acid, sodium
hydroxide, diethylenetriamine, and by using ferric bacteria inoculum, was evaluated on unprocessed spoil and treated
fractions from the density and froth flotation tests. Effective chemical leaching depended on the degree of spoil
weathering. Sodium hydroxide leaching of weathered spoil mobilized between 25 and 92% of the lead and between
3 and 23% of the zinc in unprocessed spoil. Generally, sulfuric acid and diethylenetriamine leached between 2 and
33% of the lead, and between 12 and 64% of the zinc. For previously treated spoil leaching of between 2 and 5%
of the contaminants was observed indicating a resistance to leaching in residual material. Bacterial leaching of lead
proved to be ineffective but significant movement of zinc from the spoil was recorded.
It was recommended that future work focus on the applicability of alkaline leaching and its integration with gravity
separation methods for the treatment of this type of metalliferous waste. Further work on the pilot scale assessment
and optimization of the MGS was also suggested.
20
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NATO/CCMS Pilot Study II
Project Title
CACITOX™ Soil Treatment Process
Location
United Kingdom
Technical Contact
Ken W. Brierley
British Nuclear Fuels pic
Warrington, United Kingdom
tel: 44/925-834-656
fax: 44/925-833-561
Project Status
Final Report
Project Dates
1992-1994
Costs Documented?
No
Contaminants
Heavy metals and
radionuclides
Technology Type
Soil Washing (leaching)
Media
Soil
Project Size
Pilot scale
Report Available?
Yes
CACITOX™ is a multi-component leaching process using a proprietary combination of highly selective and environ-
mentally tolerant reagents. The CACITOX™ reagent comprises low concentrations of carbonate, oxidants, and
complexing agents, which convert insoluble or absorbed contaminants into soluble complexes. The oxidant dissolves
certain metals found in their less soluble forms. The low reagent concentrations and. its high selectivity result in
minimal secondary waste. CACITOX™ is distinguished from conventional soil washing by its ability to selectively
leach the contaminants from soil as soluble chemical complexes.
The project consisted of three phases: evaluation of the process with heavy metals; evaluation with radionuclides;
and engineering design for mobile ex situ soil treatment plant. Early testing demonstrated the effectiveness of the
CACITOX™ process in reducing contaminant concentrations to regulatory levels, even with high-clay soils. There
are four stages to the process: (1) size classification, where oversize materials are sorted out and contaminated soil
volume is reduced by concentration; (2) soil leaching using the CACITOX™ reagent, with laboratory-optimized
parameters for the particular soil/contaminant conditions of the site; (3) soil/leachate separation using a bank of
hydrocyclones, followed by dewatering with filters; and (4) leachate treatment using precipitation and ion exchange
processes. Precipitated contaminants are ultimately treated by containerization, encapsulation, or dewatering. The
pilot-scale transportable plant has a capacity of 10 kg/hr, with easy scale-up to 100 kjg/hr.
Performance evaluation was accomplished at bench scale using synthetic test soils spiked with aqueous solutions of
the nitrate form of commonly encountered metals. Seven heavy metals and six radionuclides were evaluated at "low"
and "high" concentrations. Since clay soils proved the most intractable, most testing occurred with fine-particle soils.
In general, all heavy metals partitioned in a similar manner in the various soil size fractions. While the clay and
silt fractions contained the bulk of the spiked contamination, 26% of the contaminants were contained within the
coarse sand/gravel fractions. For the "high" spiked samples, the coarse fraction failed to meet the Dutch "B" Values
or Canadian Residential levels. Thus, conventional soil washing alone, which relies on particle size classification,
would be ineffective in treating these soils. Soil pH did not appear to significantly affect contaminant removal.'
While the process failed to meet regulatory levels for Cd or As spiked with 1000 ppm, it was reported that further
optimization of the reagent formulation would enable target values to be achieved. Similarly, the addition of organic
contaminants had little effect on initial leaching efficiencies, and 98% of the organics were removed from the soil.
Removal efficiencies were comparable to leaching with mineral acids, but CACITOX™ dissolved less than 10% of
the soil matrix (compared to 40% for acid washing).
Results also demonstrated that significant decontamination of radionuclide-contaminated soils occurred after a single
contact with CACITOX™, and further improvement in radionuclide removal efficiency was predicted. Only Cs
proved intractable, probably due to its monovalent state and ion size.
21
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NATO/CCMS Pilot Study II
Project Title . I
In-Pulp Decontamination of Contaminated Soils, Sludges, and Sediments
Location
Wood treatment site, United
Kingdom
Technical Contact
George Rowden
DAVY International-
Environmental Division
Stockton-on-tees
United Kingdom
tel: 44/642-602-221
Project Status
Interim Report
Project Dates
Ongoing since 1990
Costs Documented?
Estimates only
Contaminants
Metals
Technology Type <
Soil washing (adsorption)
Media
Soil, sludge, sediment ;
Project Size
Bench scale
Report Available?
Yes
In-pulp adsorption technology was originally developed for the extraction of uranium from ore and extracting gold
from matrix. In this technology, active carbon or cation exchange resins are mixed directly with the contaminated
soil slurry. It is preferable to conventional chemical leaching for finer particle sizes (silt and clay). Contaminated
substances may then be desorbed from the recovered carbon or ion exchange resin, which is then recycled. The
system reported here also includes ex situ soil washing and chemical extraction using acid or alkaline agents. If the
soil is sandy then filtration and washing is feasible, followed by precipitation or adsorption of contaminants from
solution. However, if the soil is high in clay, then washing is less practical and in-pulp adsorption is more attractive.
Current gold-recovery plants are operating at 1.2 million tons/year, which seems a reasonable size for contaminated
soil remediation plants. Laboratory data were used to design equipment for a pilot-scale plant (3,000 tons/day), and
a financial model constructed for the site showed that the treatment cost would be £70-80/ton. However, the pilot
plant was not built.
Soil quantification is a critical step, as it may not be possible to achieve low absolute standards required for some
metals such as arsenic. In these cases, pretreatment such as flotation or size separation and leaching may be
necessary, and the in-pulp process may be complimentary to other processes. The leach is necessary to render some
contaminants in a form suitable for adsorption. Various adsorption resins (strong and weak, cationic and anionic,
chelating) were tested together with activated carbon and magnetite. Ion exchange resins were preferred for Cu, Cr,
and Zn, but As removal has proved difficult, because at the very low pH (<1) necessary to dissolve the element and
avoid iron precipitation, arsenic acid is not dissociated and therefore will not undergo ion exchange. Sulfuric acid
was the most effective leaching agent, removing 90-97% of the contaminants at the test site. Copper, zinc, and
chromium metals were removed to below target levels, but As exceeded the target. Chelating reagents were able
to remove only 52% of As, and a combination of flotation, screening, and hydrocycloning achieved only 60%
removal in 80% of the soil, but still above regulatory standards. Multiple acid leaching was able to reduce As from
650 to 22 ppm (within regulatory levels), but at a relatively high cost. ,
Mercury contaminated soil was leach-tested with various acids and at various temperatures. Hg adsorption is slow,
elution is difficult, and the target of 0.5 ppm was very difficult to reach. High temperatures (550°C) achieved better
results, but did not achieve regulatory levels. Achieving low absolute levels can prove difficult and costly, while
a leachability criterion is easier to meet. :
A sample of harbor sediment heavily contaminated with organics and metals was tested with various acids. Nitric
and hydrochloric acids were successful, but sulfuric acid did not remove the lead. Because a substantial amount of
calcium was also dissolved, and would interfere with ion exchange of the contaminants, a two-stage leach was
developed. There was no observable effect by the organics on the leaching, and the organic removal could precede
or follow metal removal.
22
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NATO/CCMS Pilot Study II
Project Title
Using Separation Processes from the Mineral Processing Industry for Soil Treatment
Location
National Environmental
Technology Center, Harwell,
United Kingdom
Technical Contact
Michael Pearl
AEA Technology
Abington, United Kingdom
tel: 44/235-463-194
fax: 44/235-463-010
Project Status
Final Report
Project Dates
Costs Documented?
No
Contaminants
Metals
Technology Type
Soil washing
Media
Soil
Project Size
Pilot scale 0/2 ton/hr)
Report Available?
Yes
Physical separation techniques can be used to divide contaminated soil into fractions that can be relatively easily
treated. Physical treatment can also act as an early process in a treatment train involving chemical, biological, or
thermal processes to reduce the volume of material requiring subsequent remediation and to convert the material into
a more suitable form (such as a slurry). Although physical treatment alone could not reduce the absolute
concentration of heavy metals to acceptable levels in some soils, physical treatment in combination with a mild acid
leach was reported to reduce mobile contaminants in soil to below a leachability criterion. The reported soil washing
included physical particle separation and chemical extraction using acids, alkalis, surfactants, and complexing agents.
A number of 5-20 kg samples of contaminated soil were collected from various representative locations throughout
the U.K. for bench-scale characterization testing. Sites included former gasworks, coke works, canal dredgings,
chemical works, metal reprocessing and pickling plants, and chromium- and mercury-contaminated sites.
Contaminants included arsenic, complexed cyanides, mercury, chromium, copper, lead, nickel, zinc, PAHs, and
petroleum hydrocarbons. Twenty to fifty tons of soil from the metal reprocessing works and gasworks were
additionally sampled for pilot-scale testing.
Bench-scale analyses involved grain-size distribution and fractionating, hydrocycloine and attrition scrubbing with
various reagents, specific-gravity tests of preferential contaminant partitioning, froth flotation testing of contaminant
hydrophobicity, and magnetic susceptibility tests to determine preferential contaminant partitioning based on magnetic
properties. Froth flotation is suited to fine grain sizes but an excessive clay content interferes with flotation
performance by shielding particle surfaces from collector attachment. Therefore, in this project tests were generally
conducted by desliming the sample (removing <10|am particles) before flotation.
Clay fractions showed higher contamination than the coarser fractions. Lengthening the time of attrition scrubbing
did not appreciably remove contaminants, which is thought to result from the adsorption of contaminants within the
pores and thus not accessible to surface abrasion. Heavy metals were present in all ifractions with a specific gravity
(sg) greater than 2.8, and the greatest weight percentage of contaminants exists in the <2.5 sg fraction. The soil from
the metal reprocessing plant showed that 91.7% of the sample weight was associated with the <2.99 sg fraction, and
the TCLP result was 15 times lower than the criteria for Pb, 54 times lower than for Z:n, and 59 times lower than
for Cu. A potential treatment process for this soil was therefore reported as a combination of physical separation
as a pretreatment for fines and concentration of a substantial quantity of the heavy metals by gravity. This low
volume concentrate and the fines would be stabilized, while the remaining bulk could be acid-leached to remove
mobile species. Froth flotation studies on the fine fraction demonstrated a 53% reduction in petroleum hydrocarbons
and 45% reduction in PAHs. When applied to the <3 mm fraction from the former coke works, the technique
resulted in significant concentration of PAHs, mineral oils, and heavy metals. Ninety six. percent of the mineral oils
and 80% of the PAHs could be removed in froth concentrates, which constituted 32% of the original contaminants.
Heavy metals recovery ranged from 50-70%. Froth flotation gave a poor response in metals removal to the metal-
reprocessing and chemical works soils. Magnetic separation investigations implied that commercial exploitation of
this technique may not be cost-effective.
23
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NATO/CCMS Pilot Study II
Project Title
Demonstration of Peroxidation Systems, Inc.
Location
Tracy, California
Technical Contact
Norma Lewis
Risk Reduction Engineering
Laboratory, Cincinnati, Ohio
U.S.A.
tab (513)569-7665
fax: (513)569-7887
Project Status
Final Report
Project Dates
September 1992
Costs Documented?
Yes
Contaminants
Chlorinated VOCs
Technology Type
Photochemical
Media
Groundwater
Project Size
Pilot scale
Results Available?
Yes
The technology was demonstrated under the SITE program for the treatment of groundwater contaminated with
volatile organic compounds (VOC) including trichloroethane (TCE), tetrachloroethene (PCE), 1,1,1-trichloroethane
(TCA); 1,1-dichloroethane (DCA), and chloroform. Trichloroethane and PCE were the principal contaminants with
concentrations of about 1,000 and 100 ug/L, respectively.
i
The perox-pure™ system generally produced an effluent that contained TCE, PCE, and DCA at levels below
detection limits, and TCA and chloroform at levels slightly above detection limits. The system achieved maximum
removal efficiencies of greater than 99.9, 98.7, and 95.8 percent for TCE, PCE, and DCA, respectively. The system
also achieved removal efficiencies of up to 92.9 and 93.6 percent for TCA and chloroform, respectively. GC-MS
analysis of the influent and effluent samples for VOCs indicated that no new target compounds or tentatively
identified compounds (TIC) were not formed during treatment. However, the toxicity of the effluent to water flea
and flathead minnow was found to be greater than for the influent probably due to residual hydrogen peroxide being
present. The treated effluent met California drinking water action levels and Federal drinking water maximum
contaminant levels for all VOCs at the 95 percent confidence level. Cost analysis indicated that the groundwater
remediation cost for a 50 gallon per minute perox-pure™ system would range from $7 to $11 per 1,000 gallons,
depending on contaminated groundwater characteristics. Of this total cost, the perox-pure™ system direct treatment
cost would range from $3 to $5 per 1,000 gallons.
The perox-pure™ system uses UV radiation and hydrogen peroxide to oxidize dissolved organic compounds present
in water at parts per million levels or less. The goal is to oxidize organic compounds to carbon dioxide, water,
chlorides, or possibly simple organic acids. UV is generated by 5 kW medium pressure mercury vapor lamps. These
lamps are fitted with wipers to remove an organic coating that tends to build up during operation and may reduce
their efficiency. This treatment technology produces no air emissions and generates no sludge or spent media that
requires further processing, handling or disposal. Ideally, end products include water, carbon dioxide, halides, and
in some cases, organic acids. The principal oxidants in the system, hydroxyl radicals, are produced by direct
photolysis of hydrogen peroxide at UV wavelengths.
The perox-pure™ chemical oxidation treatment system used for the SITE technology demonstration was assembled
from the following portable, skid mounted components: an oxidation unit, a hydrogen peroxide feed module, an acid
feed module, a base feed module, a UV lamp drive, and a control panel. The oxidation unit has six reactors in series,
with one 5 kW UV lamp in each reactor, and a total volume of 15 gallons. Circular wipers mounted on the lamp
housing are used periodically to remove any accumulated solids formed as a result of oxidation of metals, water
hardness, or solids precipitation. :
24
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NATO/CCMS Pilot Study II
Project Title
In Situ Microbial Filters
Location
Kennedy Space Center, Florida
Technical Contact
Richard B. Knapp
Lawrence Livermore National
Laboratory
Livermore, California
U.S.A
tel: (510)423-3328
fax: (510)422-3118
Project Status
Final Report
Project Dates
Costs Documented?
Yes
Contaminants
VOC:
Trichloroethane
(TCE)
Technology Type
Bioremediation (in situ)
Media
Groundwater
Project Size
Bench and Pilot scale
Report Available?
No
In situ biodegradation with resting populations of TCE-degrading bacteria was reported as technically successful, but
did not meet regulatory guidelines in the Florida pilot-test due to unexpectedly high co-contamination by
chlorofluorocarbon and methane, which were preferentially degraded over TCE, and by a low oxygen content in the
groundwater. This technology is most economical for large plumes with fast-flowing groundwater and low TCE
concentrations (<10 ppm). Minimum ambient criteria include pore size of >10u (to permit bacterial transport);
groundwater pH of 7±1; low concentrations of TCE (concentrations of 25 ppm become toxic and populations must
be frequently replenished); and dissolved O2 must be high enough, with ranges given of 6.37-1.28 ppm depending
upon contaminant and concentration). The total cost for the biofiltration process was reported to be about half of
the probable pump-and-treat costs, while involving only about 10% of the volume of pump-and-treat.
Indigenous TCE-eating bacteria were collected from groundwater, cultured in surface vessels, separated from the
culture media, mixed with groundwater, and re-injected into the contaminated zone. An estimated 10% of the
injected bacteria attach to the subsurface soils. No nutrients are subsequently added, the organisms dependent
entirely upon the pollutant for their carbon intake. The enhanced population of bacteria form a biofiltration zone
below the water table through which contaminated groundwater is alternately withdrawn and injected underground
("huff-and-puff'), greatly increasing the residence time of the contaminants in contact with the bacteria.
Four major engineering considerations affect the performance of the in situ biofilter: (1) the contaminants must stay
within the biofilter long enough to be degraded, hence the "huff-and-puff pumping; (2) the degradation capacity
of a given bacterial population is fixed, since no additional nutrients are provided and key biochemicals are lost
during the degradation process; (3) there is a maximum number of bacteria that can be made to attach to the soil,
related to the groundwater chemistry, that in turn influences residence time and degradation capacity (mainly
controlled by in situ conditions); and (4) as key biochemicals are destroyed as the microbes run out of stored energy,
the biodegradation reaction eventually terminates as bacteria decompose. Bench-scale testing revealed that the
degradation capacity of the bacteria at the site was about 0.25 g/TCE per gram of bacteria. The thickness of the
biofilter varies according to the subsurface flow and the contaminant concentration, with values ranging from under
1 cm to over 50 cm, at 20°C and 108 cells/gram of sand. A 10 cm filter provided complete breakdown for 8 weeks,
and had reduced degradation capacity for up to 16 weeks.
A series of laboratory experiments concluded with empirical mathematical models that predict various biodegradation
parameters based on in situ conditions. Saturation, attachment rates, entrainment rates, and enzymatic longevity
functions were modeled, providing quantitative data for qualitative limits on engineering parameters. Where limits
exist, they are dependent upon the population longevity, the population's degradation capacity, or the residence time
of the contaminated groundwater in contact with the biofilter. Laboratory tests have shown that most soils displayed
some preferential distribution of contamination to certain physical soil fractions, but the degree was not always
sufficient for the fractions with lowest concentration of contaminants to be acceptable as inert fill. Reassessing the
soil in terms of contaminant mobility using the TCLP test rather than absolute concentration suggests the role of
physical treatment as a preparatory stage in an overall treatment train that also involves biological or chemical
decontamination.
25
-------
NATO/CCMS Pilot Study II
Project Title
Phase Transfer Oxidation
Location
Technical Contact
Mark Smith
U.S. Air Force
Tyndall AFB, Florida
U.S.A.
tel: (904)283-6126
fax: (904)283-6286
Project Status
Final Report
Project Dates
Costs Documented?
No
Contaminants
VOC: Trichloro-
ethane (TCE)
Technology Type
Photochemical Oxidation (ex
situ) for adsorbent regeneration
Media
Groundwater
Project Size
Pilot scale
Report Available?
November 1994
The "Hand-D" contaminant destruction process cleans the water in two stages. In the first stage, volatile and
semivolatile organic contaminants are adsorbed, and in the second stage adsorbents are regenerated in situ using an
advanced oxidation process (AOP). The adsorbent was reported to have a very high capacity for TCE (up to 10
times carbon for TCE and 30 times for other VOCs), and very durable. Destruction came from complete oxidation,
and advantages included on-site regeneration of the reagent and low operational costs.
Several AOP regeneration schemes were investigated, including photocatalytic destruction, H2O2/O3, and UV/H2O2.
Trials using Rohm and Haas Ambersorb 563 adsorbent and various AOPs revealed that the concept is impractical
because (1) the rate of regeneration is limited by the desorption of contaminants from the adsorbent (improvements
in oxidation catalysts do not improve the process) and (2) regeneration of the adsorbent required significantly more
oxidant than was required for the direct oxidation of contaminants in homogeneous solution. Heating the adsorbent
to promote desorption was only partially successful, requiring steam temperatures for effective desorption. The use
of steam increases costs considerably, negating the potential advantages. The regeneration required constant stirring,
and regeneration was ultimately limited by desorption. This meant that the regeneration process required much more
Ambersorb than originally estimated, making the economics questionable.
Steam desorption of Ambersorb is already a process available from vendors using a Rohm and Haas system. In the
course of the study, a significantly improved photo-oxidation catalyst was developed by doping anatase (TiO2) with
1 percent platinum. This catalyst effectively destroyed chlorinated and non-chlorinated hydrocarbons in aqueous
solution.
26
-------
NATO/CCMS Pilot Study II
Project Title
Bioventing in the Subarctic Environment
Location
Eielson Air Force Base, Alaska
Technical Contact
Catherine Vogel
U.S. Air Force
Tyndall AFB, Florida
U.S.A.
tel: (904)283-6126
fax: (904) 283-6286
Project Status
Interim Report
Project Dates
1990-1994
Costs Documented?
No (will be next year)
Contaminants
VOC: BTEX (JP4
kerosene)
Technology Type
Bioremediation (in situ
bioventing)
Media
Groundwater
Project Size
Pilot scale
Fleport Available?
No
A four-year pilot-scale project was undertaken to determine whether bioventing is feasible under arctic conditions,
and whether bioventing can be influenced by heating the soil. Preliminary conclusions from studying five controlled
plots near Fairbanks, Alaska, are that bioventing is practical, but relatively slow, and that passive warming through
black-plastic mulching of solar heat was about 1/3 the rate of active artificial warming.
Several thousand gallons of jet fuel were accidentally spilled and contaminated soil and groundwater. The
groundwater table was 6 m. The conditions at the site were extreme, with average annual temperatures at 0°C (-30°
to +30°C). There is no permafrost. Five plots were developed, with three warmed by hot water injection, surface
electric heat tape, and passive solar warmth mulched with plastic insulation. The other two plots were controls, with
no heat supplied. No nutrients or microbes were added to the plots, depending entirely upon ambient conditions.
Costs and performance will be documented in the next year's report.
27
-------
NATO/CCMS Pilot Study II
Project Title
In Situ Removal of Coal Tar
Location
Brodhead Creek Superfund Site,
Eastern Pennsylvania
Technical Contact
John Banks
Environmental Protection Agency
Philadelphia, Pennsylvania
U.S.A.
tel: (215)597-8555
fax: (215)597-9890
Project Status
Interim Report
Project Dates
September 1994 -
January 1995
Costs Documented?
No
Contaminants
SVOC (Coal
Tar)
Technology Type
Soil Washing (in situ hot water
injection)
Media !
Groundwater
Project Size
Full scale
Report Available?
No ;
Solvents and BTEX were released into an aquifer and nearby river from a former coal gasification plant. Free coal
tar exists (100% pore-volume saturation) in natural stratigraphic depressions in the saturated zone. Due to problems
associated with excavation, the site favored an in situ remediation process. A slurry wall was constructed to intercept
further flow to the river.
The method was developed to recover petroleum from oil shale deposits, and is called "contained removal of oily
wastes" (CROW). Treatability studies at this site verified 60-70% removal of coal tar, but virtually 100% of the
more mobile fractions. A pattern of six injection and two extraction wells were placed in the free-product area. Hot
water (71°C) injection will be maintained for four months. Hot water injection reduced the coal-tar viscosity and
density to less than the surrounding hot water. Oily waste and water were pumped out and cleaned on site, and the
clean water was reinjected. Dense non-aqueous phase liquids are removed by gravity separation. Mobilization and
recovery of the waste are determined largely by the temperature of the injected water. Lateral containment is
achieved by controlling the injection and extraction rates to isolate hydraulically the affected area from the
surrounding groundwater. The overall extraction rate is 570 liters per minute. The recovered residue is incinerated
off-site. ,
The Brodhead Creek site has been selected as a Superfund Innovative Technology Evaluation (SITE) project, with
close EPA-sponsored monitoring of cost and performance. These data ultimately will be published as:a SITE report.
28
-------
NATO/CCMS Pilot Study II
Project Title
Location
Atlanta, Georgia
chnical Contact
Donald Rigger
Environmental Protection Agency
Atlanta, Georgia
U.S.A.
tel: (404) 347-3931
fax: (404) 347-4464
Basket Creek Surface Impoundment
Project Status
Final Report
Project Dates
November 1991
February 1993
Costs Documented?
Yes
Contaminants
VOCs (solvents)
Technology Type
Soil Vapor Extraction
Media
Soil
Project Size
Full scale:
0.1 ha; 765 m3
Report Available?
Yes
Sampling revealed very high levels of volatile organic carbons (toluene, methyl ethyl ketone methvl isobutvl ketone
Georgia- In a11' about 765 m3 of
A temporary building was erected over the site and all excavation and soil treatment took place within this
which was mamtamed under negative pressure. Contaminated soil was excavated, scieenE^
vapor extraction technology. The entire operation is designed to control volatile emission and
Excavated soil was piled inside a temporary building to a height of about 0.6 m. Slotted well screens were placed
at various elevations m the piles, and ambient air was forced through the piles to expedite vapor
r?o?ifChed rn ?°? Ievheis fen beiow ^ ppm totai hai°«d «
of offTe aChmg ^^ ^ ** ^ "* TC& Treated soil
Extracted vapors from excavation, screening, processing, and treatment were passed through a baghouse for narticu
late recovery prior to thermal oxidation. Approximately 72,000 Ibs. of VOCs were theLllXTyed ov^ the"
29
-------
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-------
NATO/CCMS Pilot Study II
NEWLY ACCEPTED PROJECTS
The following 15 projects were accepted at the Oxford conference in September 1994 for inclusion in the Pilot Study
Three additional nominations by the United States were not accepted because they would have exceeded the limit
of four projects at any one time for the United States.
Bioremediation of Petrochemicals Following a Major Fire
Location
Petrochemical facility,
Melbourne, Australia
Technical Contact
S.H. Rhodes
Minenco Bioremediation
Services
Sydney, NSW
Australia
tel:
fax:
Project Status
New
Project Dates
November 1991 — 1995
Costs Estimated?
No
Contaminants
BTEX, VOCs
Techn
Biorei
ex siti
Media
Soil, groundwater, surface \
Project Size
Full scale
Result
N/A
Bioreimediation (in situ and
A fire in August 1991 at a petrochemical storage facility resulted in extensive contamination of soil and groundwater
Also, 12 million liters of contaminated fire-fighting water was collected and stored for subsequent decontamination
Contaminants included BTEX, phenol, methyl ethyl ketone, and others. Soil contamination with phenol was
measured up to 24,000 ppm, along with high concentrations of VOCs. Laboratory testing with cultured microbes
on 1 million liters of water reduced phenol concentrations from 1,400 to 50 mg/1 in four days. Phenol is highly toxic
to microbes in concentrations above about 4,000 ppm. Testing demonstrated, however, that the phenol toxicity could
be managed using slurry bioreactors and in situ simulations. Very rapid degradation was demonstrated in the
laboratory, where phenols were reduced from 11,000 to 170 ppm after 11 days. The microbial culture was prepared
on site in batches and added (together with appropriate nutrients) to the contaminated water. After about two weeks
biotreatment of impounded water was complete; total phenols were reduced to <0.1 mg/1 and the Microtox EC test
showed no residual toxicity. 51)
A field trial of the proposed process was carried out using 100 tons of soil from selected hot spots The trial
demonstrated the rate and extent of phenol removal, as well as its fate and any limiting parameters Initial soil
phenol concentrations averaged 1,200 ppm, which was reduced to <0.1 mg/L in two clays. Soil microbiology
revealed a 10-fold increase in total heterotrophs and phenol degraders within two weeks, then continuing increases
over the trial period from 10s to 107 per gram. The pilot trial lasted 45 weeks, and resulted in a steadily declining
phenol mass. After the trial period, approximately 90% of the phenol was degraded in situ and about 10% was
removed by flushing (and was degraded in the recirculating leachate tank bioreactor).
In situ treatment of 1,600 m2 of phenol-contaminated soil began in May 1993, with addition of controlled-release
nutrients, mixing of surface soil, and regular irrigation with batches of treated water (from the bioreactor) Treatment
of an additional 3,000 m commenced in September 1993. Soil phenol levels decreased rapidly in the top 60 cm
from levels as high as 1,800 ppm to below 100 ppm.
31
-------
NATO/CCMS Pilot Study II
Project Title
Bioclogging of Aquifers for Containment and Remediation of Organic Contaminants
Location
Former fuel service station
Adelaide, South Australia
Technical Contact
C. Johnston
CSIRO Division of Water
Resources
tel:
fax:
Project Status
New
Project Dates
Costs Estimated?
•No
Contaminants
BTEX and VOCs
Technology Type
Biological containment (in
situ) •
Media
Groundwater
Project Size
Pilot scale
Results Available?
N/A
Temporary containment of organic non-aqueous-phase liquids and dissolved organic contaminants can be
accomplished by manipulating bacteria in situ to produce polysaccharides (slimes), thereby reducing hydraulic
conductivity around sources and providing an isolated zone for subsequent remediation. Biological clogging of
aquifers is often regarded as a nuisance adjacent to boreholes, but this phenomenon can have potential benefits.
Since stimulation of microbial activity can also lead to degradation of NAPLs, this bioclogging zone becomes a
biologically active barrier to containment spread.
The project will determine conditions favorable to the production of polysaccharides, identify appropriate bacterial
strains, and develop appropriate injection methods. The proposed study integrates research on the intrinsic
bioremediation of dissolved organics and aquifer clogging by bacteria to reduce seepage. '.
The project will include a pilot-scale field experiment to determine the efficiency of available carbon and nutrient
delivery systems to achieve optimum conditions for bacterial polysaccharide production. This will aim to reduce
hydraulic conductivity enough to temporarily isolate the contaminated zone.
32
-------
NATO/CCMS Pilot Study II
Remediation of Methyl Ethyl Ketone Contaminated Soil and Grounc
Location
Petroleum distribution center
Australia
Technical Contact
Trevor Bridle
Environmental Solutions
International, Ltd.
Leederville, West Australia
tel: 61/09-242-2422
fax: 61/09-242-1822
Project Status
New
Project Dates
August 1994
onward
Costs Estimated?
No
Contaminants
MEK
Media
Soil and groundwater
Project Size
Full scale
Tec
Put
Soi
Res
N//
Technology Type
Pump-and-Treat and
Soil Vapor Extraction
Results Available?
Significant contamination has accumulated over the years at a petroleum distribution, center, resulting in plumes of
methyl ethyl ketone in the groundwater. The site is being remediated using a combination of soil vapor extraction
and on-site treatment of recovered groundwater and vapors. Preliminary pump testing has revealed up to 130 m3/
hour flow of groundwater contaminated with up to 5,000 mg/1 ketone, air stripping treatment streams up to 100 m3/
hour contaminated with up to 1,500 mg/Nm3 MEK vapor, and up to 5 mVday of recovered hydrocarbon product
Environmental regulations permit up to 300 mg/1 in treated groundwater and 10 mg/Nm3 in the stack exhaust An
MEK stripper, vacuum extraction system, and afterburner were designed and built in mid-1994.
Contaminated groundwater passes through an oil/water separator prior to being air-stripped. The custom-designed
stripper provides at least 90% MEK removal. Stripped groundwater is tested for compliance with standards prior
to being discharged into a sewer. Contaminated air from the stripper is combined with fumes from the vacuum
extraction manifold and fed to an oxidizer/afterburner, where it is burned at 760°C.
The system was commissioned in August 1994 and preliminary performance data for the customized air stripper has
been reported. Even for low MEK concentrations in the influents (<1000 mg/L) a 90% removal efficiency has been
obtained at temperatures >60°C with stripped groundwater concentrations reportedly well below the 300 mg/L limit
Unusual residual benzene concentrations of about 10 ppm in the groundwater, normally easily stripped, are probably
due to the solubility of benzene in MEK.
33
-------
NATO/CCMS Pilot Study II
Project Title _. _ , .
Rehabilitation of a Site Contaminated by Tar Substances Using a New On-Site Technique
Location
Former Gasworks
Copenhagen, Denmark
Technical Contact
Inge-Marie Skovgaard
Environmental Protection Agency
Copenhagen, Denmark
tel: 45/32-66-0100
Project Status
New
Project Dates
18 months
Costs Estimated?
Yes
Contaminants
VOCs, SVOCs (Tar
Substances)
Technology Type
Thermal .
Media
Soil
Project Size
Full scale
Results Available?
N/A
A former coal gasification plant in Copenhagen is heavily contaminated with light and heavy tar substances,
including PAHs. The project is dealing with two former tar reservoirs, which approximately measure 1,000 square
meters, each with a total estimated contamination content of 12,000 tons. Analysis measurements estimate nearly
75,000 mg tar/kg soil near the bottom of the reservoirs, but most of the soil contains between 200 - 1,000 mg tar/kg
soil. This project proposes to demonstrate an innovative, two-step thermal treatment of the soil, with contained air
emissions. This will be the first full-scale application of this technique.
During the first step VOCs will be removed and the overall soil moisture content reduced. The second stage will
incinerate the soil at a higher temperature, degrading the SVOCs such as PAHs. The two-step process optimizes
the energy use, since relatively low-cost energy is used to evaporate the ambient water. The entire treatment area
(tar reservoirs as well as the treatment plant) will be enclosed in a ventilated tent. Noxious emissions will be
removed using activated carbon. It is anticipated that the technique can remediate soil contaminated with up to
75,000 ppm tar, permitting reuse of the soil.
The total cost of the project is estimated to be DKK 18.1 million (ECU 2.4 million). The project is financed by EU,
the City of Copenhagen, and the Danish EPA. The preliminary result from the on-site thermal treatment plant
indicates that it is possible to clean tar contamination (the 16 EPA-PAH) from approximately 20,000 ppm to less
than 10 ppm (99.5% cleaning).
34
-------
NATO/CCMS Pilot Study II
Project Title
Innovative In Situ Groundwater Treatment System
Location
Former paint plant
Aubagne, France
Technical Contact
Gerard Marceau
ICF Kaiser Environnement
Gennevilliers, France
tel: (1)46-88-9900
fax: (1)46-88-9911
Project Status
New
Project Dates
14 Months
Costs Estimated?
No
Contaminants
VOCs (Tetrachloro-
ethylene)
Technology Type
Air Snipping
Media
Groundwater
Project Size
Full scale
Result:; Available?
N/A
At a former paint plant in Aubagne, tetrachloroethylene (PCE) exists in groundwater at concentrations of 3 to 4 ppm
(10,000 ppm in soil). An innovative in situ air-stripping system will be used to remediate the groundwater to
concentrations below 1 ppm. Fifteen special vapor extraction wells will be drilled in, the area. These special wells
consist of two co-annular wells (a small-diameter well within a larger-diameter well). The inner well extends from
the ground surface into the saturated zone, and is screened in the contamination zone (approximately 27 m). The
outer well extends through the vadose zone and terminates above the water table (approximately 5 m). An air
injection line with a diffuser in the inner well produces bubbles of a controllable size. The rising bubbles strip the
VOCs from the groundwater. Air injection is planned at a rate of 60 mVhour, which is capable of lifting 30 m3/hour
of water. The rising bubbles cause a vertical circulation of contaminated water.
A numerical model of bubble flow and phase transfer has been developed that permits estimates of flow patterns,
pressure gradients, gas and water velocities, and mass transfer characteristics. According to the model, flow pattern
and mass transfer of VOCs between the water and gas phases are largely controlled by bubble diameter.
This technique is estimated to be 10-15% cheaper than conventional pump-and-treat technologies, and additionally
requires little maintenance, no secondary water disposal, and consolidates the contaminant into a single phase (air).
Disadvantages include potential cross-contamination of a shallower aquifer and impact on groundwater levels.
35
-------
NATO/CCMS Pilot Study II
Project Title
Treatment of Polluted Soil in a Mobile Solvent Extraction Unit '
Location
France
Technical Contact
[No Contact Provided]
GRS
Paris, France
tel: (1)53-69-6180
fax: (1)47-34-6855
Project Status
New
Project Dates
Costs Estimated?
No
Contaminants
SVOCs (PAHs, PCBs,
Pesticides, other heavy
organics)
Technology Type
Soil washing (proprietary
solvents)
Media
Soil
Project Size
Pilot scale
Results Available?
N/A
A new mobile industrial pilot-scale capability is being demonstrated to treat fine soils contaminated with high
molecular weight organics such as PAHs and PCBs. The soil preparation and feed system, solvent regeneration, and
soil dryer are proven technologies. The innovative components include the modified flotation cells for fine particles
and the separation of fine particles by controlling surface tension.
The process is expected to reduce contaminant concentration by 95-99%, and can be applied to PAHs, PCBs, pesti-
cides, and heavy petroleum oils. The mobile pilot process, which is transported in three trailers, can be set up within
two days and can handle 2-5 tons/day. The process operates under reduced air pressure, thus preventing emissions
to the atmosphere. There also is no aqueous effluent. The cleaned soil contains about 10 ppm solvent, but this is
easily biodegradable. During process operation the temperature of the soil does not exceed 100°C even within the
soil dryer. Solvent vapors are distilled and recycled; contaminants are ultimately incinerated off-site.,
36
-------
NATO/CCMS Pilot Study II
Location
Germany
Technical Contact
Arno Klusmann
Ruhrkohle
Umwelttechnik GmbH
Bottrop, Germany
tel: 49/02041/166-610
fax: 49/02041/166-612
Mobile Low Temperature Thermal Treatment Process
Project Status
New
Project Dates
1994 onward
Costs Estimated?
Yes
Contaminants
VOCs, Chlorinated
VOCs, Mercury
Technology Type
Thermal (low temperature)
Media
Soil (fine-grained)
Project Size
Pilot scale
Report Available?
N/A
A mobile, low-temperature treatment process has been developed to deal with highly volatile contaminants in fine-
grained soils. This process produces virtually no waste gas and is intended to treat contaminants such as chlorinated
solvents and mercury where the off-gas produced by high-temperature combustion would otherwise require further
treatment and regulatory licensing. The evaporated contaminants are collected for off-site handling or disposal.
Soil screened to a particle size <15 mm is heated within a gas-tight evaporator to 290°C under continuous agitation
for 30-45 minutes. Final temperature depends upon the contaminants. Steam injection is used to accelerate
contaminant removal, particularly for hydrocarbons. This step essentially is a thermal phase-transfer operation,
stripping the volatiles from the soil into gaseous phase. The cleaned soil is cooled and wetted (7-10% moisture)
after which it can be returned to the site for reuse. niuisnire;,
Exhaust gases from the evaporator contain a high water content, and are cooled by condensation to 5°C Hydrocar-
bons and mercury are separated from the water, which is fed into a water treatment plant for use in the soil cooling
unit The .contaminants themselves are separated into a light phase (low-boiling hydrocarbons) and heavy phase
(high-boiling hydrocarbons and mercury), and ultimately recycled or treated elsewhere. Residual gas from the
condensation step is removed with activated carbon. 8
Experiments have demonstrated reduction of VOCs in soil from 1,000 ppm to 0.01 ppm. Mineral oils in sand were
reduced from 2,680 ppm to 10 ppm and from 38100 ppm to 61 ppm in clay. Mercury was reduced from 280 to 44
ppm m sand and from 1 1,000 to 83 ppm in clay. According to experimental data, costs of cleaning mineral oHs or
u°n rim™ f °Ut US$125/t°n- F°r Chlorinated hydrocarbons or mercury the cost might rise to $150/ton and
up to US>;j)190/ton for munitions wastes.
effectivr ,tra"Sp°rtation costs and the cost* "-ocialed with obtaining permits, is cost-
ettective for 800 tons or more of soil when compared to a fixed central facility.
37
-------
NATO/CCMS Pilot Study II
Project Title
Location
Germany
Fluidized Bed Soil Treatment Process "BORAN"
Project Status
New
Contaminants
Chlorinated and non-
chlorinated SVOCs
Technology Type
Thermal
Project Dates
Media
Soil and slurry
Costs Estimated?
No
Project Size
Pilot scale
Report Available?
N/A
Technical Contact
[No Contact Provided]
Bodenreinigung GmbH
Berlin
tol: 49/30-393-1078
fax; 49/30-391-1197
_—-—
A rotating fluidized-bed system has been designed to improve mixing of solids during combustion. Contaminated
soil initially is screened to <20 mm. Oversized material is transferred elsewhere for safe disposal. Controlled
eHiptical circulation produces superior lateral mixing and turbulence, which also enhances combustion efficiency.
UnfS temperature distributions induce complete combustion of PAHs and PCBs. The furnace operates continu-
ously at 900°C, using fuel oil supplied at the rate of 725 liters/hour, since the contaminated soil has a negligible
calorific value. A downstream flue-gas cyclone removes soil particles swept into the exhaust gas; this cyclone has
a capacity of 7.5 tons/hour, and will remove up to 85% of the entrained fines. Flue gas is then passed to an
afterburner (1,200°C) and quench chamber prior to being recycled to the combustion air preheater. ;
Gas cleaning is accomplished by adsorption in two steps. Primary adsorption of organics is accomplished by
continuous Edition of sorbent to the furnace, mixed in with feedstock soil. Flue gases are cooled and condensed
prior to secondary inorganic adsorption. Fresh limestone is injected into the gas downstream to increase adsorption
of HC1 and SO2. Entrained fines and reaction products are separated in a bag filter with further limestone adsorption.
Residual organics, including dioxins and furans as well as heavy metals, are adsorbed in two activated carbon filters.
The used filters are fed back to the fluidized bed reactor.
38
-------
NATO/CCMS Pilot Study II
Slurry Decontamination Process
Location
The Netherlands
Technical Contact
Rene H. Kleijntjens
Biotechnology Integrated
Research & Development
Schiedam, The Netherlands
tel: 31/41-57822
fax: 31/43-79648
Project Status
New
Project Dates
1993-1995
Costs Estimated?
Yes
Contaminants
Organics
Technoli
Bioremi
Media
Soil (clay slurries and sediments)
Project Size
Pilot scale
Report A
N/A
Contammated wet clays and peat soils are expensive to treat thermally, but are promising candidates for a slurry
decontaminate process. Bench-scale experimentation has documented the strengths and potential applicationsTf
he slurry decontamination process (including biological oxidation of contaminants, mobile/fixed installations, and
lack of secondary wastes). The current drawbacks to the system include inadequate final decontamination leve?s
restriction to organic pollutants, and high price (compared to land farming).
The pilot study objectives are to design and construct a pilot plant by 1993; establish process parameters, determine
costs, and design a full-scale plant in 1994; and enter the market in 1995.
Contaminated soil is mixed and sieved; coarse fractions are washed and dewatered conventionally. The fines are
treated in cascading bioreactors before they are dewatered. Off-gases are passed through biological filters and
process water is recycled internally. The end product is a pressed clay cake. The pilot-sea e plant has demonstrated
a remediate of 3,000 to 200 ppm of oil in 60 days; the remediation proceeded very rapidly (down to 500 ppm after
39
-------
NATO/CCMS Pilot Study II
Project Title
,=_= — — _=—=—=— =—
Use of White-Rot Fungi for Bioremediation of Creosote-Contaminated Soil
ay
t
ly
00
110
Project Status
New
Project Dates
July 1994 — November
1995
Costs Estimated?
No
—
Contaminants
PAHs (Creosote)
Technology Type
Bioremediation (ex situ)
Media '
Soil
Project Size
Pilot scale
— ========
Report Available?
Location
Jordforsk, Norway
Technical Contact
Trine Eggen
Jordforsk
1432 AS, Norway
tel: 47/64-94-8100
fax: 47/64-94-8110
.„
Lignin, a component of woody plants, is resistant to attack by most microorganisms. White-rot fungi have unique,
nonspecific mechanisms that enable them to degrade lignin. The fungi produces several extracellular enzymes
(phenoloxydases) that oxydize lignin and other complex and hard biodegradable compounds, including a wide range
of pollutants.
The first part of the project was a screening test that included optimalization of growth (type of substrate, pre-
treatment of substrate, water content) and evaluation of various organic additives^ Underway are bench-sea e
radiolabelling experiments to study the production of metabolites during degradation and otoer bench-scale
experiments to examine the stimulating effect of compost on the humification of high-weight PAHs.
Bench-scale composting experiments, planned for January to May, 1995, will compare two-phase composting (pre-
optimizing soil and inoculation with fungi) to one-phase composting (inoculation without soil optimization). A pilo
tet, scheduled for June-November 1995 at an abandoned mine in Norway, will be conducted under optimal
conditions.
40
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NATO/CCMS Pilot Study II
Soil Washing and DCR Dehalogenation of PCB-Contaminated Soil
Location
Norway
Technical Contact
James Berg
Aquateam
Oslo, Norway
tel: 47/22-67-9310
fax: 47/22-67-2012
Project Status
New
Project Dates
July 1994 - November
1995
Costs Estimated?
No
Contaminants
Chlorinated SVOCs
(PCBs)
Media
Soil
Project Size
Pilot scale
Technology Type
Soil Washing and DCR
dehalogenation
Report Available?
N/A
One of Norway's largest energy distribution companies has a transformer-storage area contaminated with PCBs
(about 1,000 metric tons). The only commercial treatment alternative, export and incineration, is prohibitively
expensive. An innovative process of soil washing (for volume reduction) and DCR dehalogenation of enriched
sludge is being considered for on-site remediation. The principal advantage of this process is that small volumes
of wet soils can be economically treated.
After a pilot soil washing 4 m3 of material, a "clean" fraction-about 70% by volume of the original material-had
a PCB concentration of <10 ppm compared with untreated soil values of about 100 ppm. Bench tests have shown
that soil contaminated with 1,000 ppm could be reduced to about 50 ppm using simple additives and increasing
temperature and pH. In a recently completed pilot test, 4 m3 of soils containing about 400 ppm PCB were treated
to <10 ppm under optimal conditions, with a volume reduction of about 70%.
The DCR dehalogenation process involves two steps. In the first step, wet sludge is chemically dispersed and
dehydrated with hydrophobized lime. In the second phase, a nucleophilic reagent is added that dehalogenates the
matrix.
The soil will be treated at the site using a 2 tons/hour mobile washing plant. The treatment goal for the clean
fraction produced by the soil washing plant has yet to be set by the regulatory authorities, but is assumed to be about
10 ppm PCB. The cleaned soil will be stored on site with a soil cap. The dehalogenation of PCB involves an
exothermic chemical disintegration, after which it is dispersed into a fine powder.
41
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NATO/CCMS Pilot Study II
Project Title
In Situ Soil Vapor Extraction Within Containment Cells
Combined with Ex Situ Bioremediation and Groundwater Treatment
Location
Abandoned Coal Processing
Plant and Cokeworks
Derwenthaugh, United
Kingdom
Technical Contact
Paul Theile
Miller Environmental Ltd.
West Yorkshire, United
Kingdom
tel: 44/977-555-427
Project Status
New
Project Dates
1991 - 1996 (total)
1993 — 1994 (this aspect)
Costs Estimated?
Yes: £8 million
Contaminants
VOCs (benzene),
SVOCs (phenols,
PAHs), free oil
Technology Type
Soil Vapor Extraction (in
situ) and Bioremediation
(ex situ)
Media
Soil, groundwater
Project Size
Full scale
(55 ha)
Report Available?
N/A
This represents the first multi-process (integrated) remediation project in the U.K. The site, bounded by rivers, is
designated as a strategic wildlife corridor and Site of Special Scientific Interest. Investigations have shown that the
site encompasses areas of high toxicity hazardous waste, impractical to move off site. This current phase of the
project, estimated to cost £2.9 million, involves the remediation of 7.9 ha encompassing the coke works portion of
the site.
Both soil and groundwater are significantly contaminated with a range of oil, volatile organics (including benzene
in very high concentrations), phenols, and PAHs. Evidence was found of groundwater migration off site to the
adjacent River Derwent. The first stage of the remediation was to install a cutoff wall through the shallow aquifer
to prevent river water from entering the site as well as to prevent the contaminant plume from reaching the river.
Free phase and vapor recovery is accomplished with vacuum extraction, with parameters established following a field
trial. The field trial involved six 100 mm and four 50 mm wells drilled to 5 m depth and connected to a vacuum
unit'through a liquid/gas separator and activated carbon units. After 14 days of static operation, the wells then were
used to gradually depress the water table. The effective radius of influence of the 100 mm wells was greater than
the smaller wells, averaging 18.5 m. Following the phase I field trials, an additional 33 100 mm wells were installed
for the full-scale operation, and operated for between 6 and 34 weeks. Following the dual vacuum extraction of
vapor and free product, excavation commenced. A significant amount of contaminated water (100 rnVday) was
extracted during the drawdown of the water table. This water was processed on site using a combination of flotation
(for oil), precipitation of metals, and chemical oxidation of cyanides and sulfides, and then discharged into the river
after pH adjustment and filtration. To-date, 12000 m3 of contaminated water has been treated with over 3000 kg
of oil recovered.
A total of 94,000 m3 of soil will be excavated, of which 28,000 m3 is suitable for biological treatment (ex situ land
farming). Following vapor recovery and dewatering of treatment cells (plots), excavation was begun and is currently
proceeding. Initial analysis shows between 3.7-5.1 x 108 colony forming units (CPU) per gram of soil. With
naphthalene as the sole carbon source, microbial counts remain a relatively high 2-8.8 x 108 CFU/g. Inorganic
nutrients were added to the soil, with resulting increases in biological activity. Laboratory evaluations of parameters
and optimization levels are on-going. Ultimately, cleaned soil will be encapsulated and stored on site.
42
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NATO/CCMS Pilot Study II
Enhancement Techniques for Ex Situ Separation Processes
Particularly With Regard to Fine Particles
Location
United Kingdom
Technical Contact
Paul Bardos
Nottingham Trent University
Nottingham, United Kingdom
tel: 44/602-418-418
fax: 44/602-486-507
Project Status
New
Project Dates
September 1994 —
October 1995
Costs Estimated?
N/A
Contaminants
Organics, heavy
metals
Media
Soil, groundwater
Project Size
Bench scale
Technology Type
Soil washing
Report Available?
N/A
Ex sou soil separation processes (often referred to as "soil washing"), mostly based on mineral processing techniques
are widely used in Northern Europe and America for the treatment of contaminated soil. The separation processes
are used for removing contaminated concentrates from soils, to leave relatively uncontaminated fractions that can
then be regarded as treated soil. It is beginning to be used in the United Kingdom. At present, commercial soil
separation is mostly restricted to the removal of fine fractions, which normally contain the highest concentration of
contaminants, leaving the coarse fractions relatively clean. However, this process is not effective where the
contaminants are not concentrated in the fines, nor is it economical where the fine fraction constitutes a significant
proportion of the soil mass. Enhancement of soil separation processes and the development of downstream processes
for treating fine fractions are necessary to increase the range of soil types treatable by soil washing and to reduce
the volume of secondary wastes that require disposal.
This project will use samples of actual contaminated soils representative of sites in the United Kingdom Contamin-
ants will include both organics and metals. Considerable effort has been spent on developing laboratory
characterization and pilot-scale monitoring procedures for the separation treatment of contaminated soils This work
will be extended to investigate and critically review process-enhancement alternatives to identify economical ways
to reduce treatment volumes. The project will investigate how fines inhibit soil washing by considering initial
materials handling and feed preparation, including evaluating opportunities for improving feed preparation and
downstream liquid/solid separation of these fines.
Laboratory and pilot-scale work will be completed by August 1995 and a final report, considering the technical
feasibility of full-scale applications, likely treatment costs, and potential market factors, will be completed bv
November 1995.
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NATO/CCMS Pilot Study II
Project Title
Multi-Vendor Treatability Demonstration of Bioremediation Technology
Location
Sweden, New York
United States
Project Status
New
Contaminants
Chlorinated
VOCs
Technology Type
Bioremediation
Project Dates
July 1994 — October
1995
Media
Soil
Costs Estimated?
No
Project Size
Pilot scale
Report Available?
N/A
Technical Contact
Annette Gatchet
Environmental Protection Agency
Cincinnati, Ohio
tel: (513)569-7697
fax: (513)569-7620
James B. Harrington
NYS Dept. of Environmental
Conservation
Albany, New York
tel: 518-485-8792
fax: 518-457-7743
'"":,,_" -' !- "^
This orphan site, located in the town of Sweden, near the city of Rochester, New York, was used for the disposal
of drummed liquid wastes. More than 2,400 drums have already been removed from this site. The residual
contamination will be treated using conventional excavation and low temperature thermal desorption unless one of
the alternative treatment technologies being demonstrated proves to be cost-effective. Three competing technologies
were selected from 13 proposals. Two of these technologies treat only soil while the other treats soil and
groundwater. The requirements for the demonstration only specified soil treatment.
The first technology is an in situ bioventing process consisting of 27 wells connected to an air extraction unit. There
are an equal number of injection and extraction wells. The injection wells deliver necessary ammonia and methane
nutrients The second technology involves two identical ex situ "biovaults" in which contaminated soils are placed.
Nutrients, moisture, pH, temperature, and oxygen levels are controlled. The first biovault is being operated under
aerobic conditions and the second is switched between aerobic and anaerobic conditions. The second biovault will
allow both oxidizing and reducing conditions to develop and will be used to assess the impact of reducing conditions
on biological degradation of chlorinated contaminants. The third technology is a vacuum-vaporized well process that
uses in situ bioremediation to treat saturated and unsaturated zones and groundwater contaminated with VOCs.
Naturally occurring microorganisms will be used. An ex situ bioreactor will be used for off-gases. The system,
contained within a 0.4 m diameter well, comprises a submersible circulation pump, bioreactor, and an air source to
strip volatiles and enhance biodegradation. The system is designed to treat an extended volume of soil by
groundwater circulation. This system is capable of adapting to the site's fluctuating groundwater levels.
This project was proposed to NATO/CCMS because of its unique approach in using competition and demonstration
as part of the remediation process. The biovaults and bioventing testing were completed in December 1994.
Analytical data from the last sampling event has been received and is being analyzed. Final reports are expected
by July 1, 1995. The vacuum-vaporized well processes will continue through October 1995.
44
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NATO/CCMS Pilot Study II
Integrated Pneumatic Fracturing/Bioremediation for the In Situ Treatment of Contaminated Soil
Location
United States
Technical Contact
Stephen C. James
Environmental Protection Agency
Cincinnati, Ohio
tel: 513-569-7877
fax: 513-569-7680
Project Status
New
Project Dates
Costs Estimated?
No
Contaminants
VOCs (BTEX)
Technology Type
Fractiiiring/bioremediation
Media
Low permeability soil
Project Size
Pilot scale
Report: Available?
N/A
The objective of this project is to demonstrate that fracturing of low permeability strata will increase permeability
and lead to enhanced in situ biodegradation. The microbial population will be stimulated by injected nutrients and
oxygen. BTEX concentrations in the soil range from 120-150 ppm. The target is 95% reduction within the top 1.6
m of soil.
The pneumatic fracturing process involves the injection of high-pressure air at controlled flow rates in the
contaminated zone. This process will create conductive channels in the formation. The, vapor movement in the
formation becomes controlled by convection and diffusion instead of by diffusion alone, thus increasing permeability
and the exposed surface area of the soil.
In situ biodegradation conditions for maximum rates and durations will be determined for indigenous microbial
populations, and seed cultures will be developed if necessary. A pneumatic fracturing system with the capability
of injecting microbes already has been designed. The system also will employ pneumatic fracturing to enhance
stacked aerobic, denitrifying, and methanogenic microbial processes in staggered spatial distribution for maximum
effectiveness. Aerobic processes will dominate at the fracture interfaces. Depletion of oxygen during aerobic
biodegradation will allow the formation of methanogenic populations at greater distances from the fractures.
Produced methane will be diffused out with the pneumatic sweep air.
45
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NATO/CCMS Pilot Study II
GUEST PRESENTATIONS
"Solidification Application: Solidification of Fly Ash Samples Coming from Solid Waste Incineration Plant"
(1993) Ayse Filibeli, Dokuz Eylul University, Izmir, Turkey
The application of solidification/stabilization technologies to the treatment of fly ash from a domestic solid waste
incineration plant was reported. Fly ash samples taken from the electrofilters of a plant near Trimmis, Sweden were
tested with a number of solidification mixes and reagents. At present fly ash from the plant is "washed" before being
sent to the disposal area representing an increased cost of about 6 to 8 DM per metric ton of domestic solid waste.
Solidification was evaluated as a more cost-effective alternative to "washing."
Fly ash samples taken from the incineration plant were solidified by the addition of additives including cement,
calcium oxide, calcium hydroxide, gypsum, and sodium silicate. After a curing period of 28 days the solidified
samples were tested for compressive strength and for the leaching of contaminants using the German DIN tests.
The majority of solidified samples had compressive strengths of at least 500 kN/rn2. Leaching test results showed
that a high proportion of the pollutants were fixed within the solidified mass. The costs of the solidification process
was in the order of 0.21 to 2.7 DM per metric ton of domestic solid waste suggesting that this process may represent
a cost-effective alternative to fly ash "washing."
"Selection of Remedial Technologies" (1993) Paul Richter, New Jersey Department of Environment and
Energy, U.S.A.
A detailed review of chromium geochemistry, toxicology, chemical analysis, was conducted to identify potential
remedial strategies for sites contaminated with chromium wastes. An in situ treatment for reducing chromium (VI)
to chromium (HI) was suggested.
"Prediction and Optimization of the Abiotic Environment in Landfarms to Enhance Biodegradation" (1994)
Jan Freyer, University of Amsterdam, Amsterdam, the Netherlands.
Mathematical models combined with simple, inexpensive laboratory methods were used to predict biodegradation
processes and landfarm scenarios such as effect of treatment compared to non-treatment; determining the rate-limiting
thresholds for hydrocarbon concentration; and predicting the biodegradation rates for given soil parameters.
Landfarming was described as an ex situ bioremediation process for soils contaminated with petroleum hydrocarbons.
Contaminated soil is typically excavated and spread on an impermeable foil in layers of about 1 m. Biodegradation
is stimulated by aeration, irrigation and drainage, mixing, and adding nutrients and heat. The solid phase is immobile
while the aqueous and gaseous phases are mobile. Landfarming is a common European technique because of its
environmental and economic advantages.
Present research is focused on optimizing the biodegradation process as well as developing improved monitoring
methods and evaluating the risk associated with the residual materials. Chemically, the degradation of hydrocarbon
contaminants occurs through the biological oxidation of the hydrocarbon into biomass and the release of CO2 and
water. This reaction is commonly referred to as "mineralization" of hydrocarbon. Criteria for mineralization include
the presence of non-chlorinated hydrocarbons, inorganic nutrients (N, P, K) are not rate-limiting, O? and water are
present, and an appropriate temperature.
The use of mathematical models was reported to simulate the dynamics of environmental parameters in soils, in
quantifying the microbial response to the environmental factors thus computing a degradation rate, and applying
calibrated models to evaluate various treatment scenarios in landfarms. Three deterministic, one-dimensional
transport models (gas, heat, water) and one empirical biodegradation model were developed. Simple laboratory
measurements of transport coefficients were used to calibrate the models, and boundary conditions were assumed
from typical landfarming scenarios. Models were evaluated at existing experimental landfarms in large outside
lysimeters. The distribution of substances and energy in soils is governed by transport processes that determine the
biodegradation rate.
46
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NATO/CCMS Pilot Study II
Research will concentrate on refining and simplifying field methods to monitor biodeg;radation rates to reduce costs,
as well as to introduce new data sets into current models to refine them and quantify uncertainties.
"Controlled In Situ Groundwater Treatment" (1994) James F. Barker, University of Waterloo, Waterloo,
Ontario, Canada.
Plumes of groundwater contamination extend from sources commonly present in the subsurface (DNAPLs or
LNAPLs), even below the water table. Many of these subsurface sources of contamination are very difficult to
remediate. Pump-and-treat can provide an effect means of hydraulically containing the sources; however, at many
sites pump-and-treat will have to continue for many decades because the source zones dissipate slowly. Projected
long-term operation and maintenance costs are therefore large.
A new approach for source-zone and plume containment that is more passive and that offers considerable potential
for long-term cost savings is contaminant treatment using permeable, in situ treatment zones. Aspects of this
approach have been developed by the University of Waterloo (Canada). A treatment zone, or "wall," is composed
of permeable material placed across the contaminant plume. The desired treatment is generated by either flushing
the required chemicals into the wall or by having the required chemicals emplaced as; solids in the wall. Another
approach is the "funnel-and-gate" system (patent pending). In this system, low permeability vertical barriers are
placed across plumes. Gaps, or "gates," in the barrier allow passage of the plume through a. reactive medium so that
the water is treated while passing through. The objective is to cause the plume to meet water quality standards on
the down-gradient side of the system.
University researchers have developed various approaches for in situ treatment of a wide variety of common organic
and inorganic groundwater contaminants, including chlorinated solvents, petroleum-derived contaminants such as
BTEX, metals, nitrate, and phosphate. Intensive laboratory and several prototype field trials have been conducted.
Designs for full-scale systems have been developed and several means of installing the systems compatible with
various geological and geotechnical conditions are now available for unconsolidated or semi-consolidated deposits
to depths of over 30 m. Design options for funnels range from scalable joint steel piling to conventional soil-
ben tonite slurry walls. Options for gates include permanent installations of reactive, media to easily removable
cassettes of reactive materials that are positioned in the gates for a specified period and conveniently replaced later
when reactive material is consumed. In some systems, plumes with complex contamination are treated in gates
having a series of reactive media.
"U.S. Air Force Bioventing Initiative" (1994) Andrea Leeson, Battelle-Columbus, Columbus, Ohio, U.S.A.
Bioventing is the use of subsurface injection and withdrawal of gases to stimulate biodegradation. The technique
frequently results in volatilization; soil venting (also known as soil vacuum extraction) frequently results in
biodegradation. Bioventing is useful to treat nonvolatile biodegradable contaminants and to improve the performance
and economics of biodegradation.
The Air Force is demonstrating the effectiveness of bioventing at 138 sites across the country, collecting cost and
performance data. As of September 1994, 121 sites have been tested, 92 systems are running, and 50 sites have been
operational for at least one year. The goal is to obtain nationwide regulatory acceptance of the technique. Data will
ultimately be used to produce, jointly with the U.S. EPA, a bioventing design manual!
Field treatment consists of a six-stage protocol: (1) a soil-gas survey for baseline characterization; (2) Install vent
well, monitoring points, and a background well; (3) conduct in situ soil-gas permeability tests; (4) conduct in situ
respiration tests; (5) install a 1 to 2Vz horsepower blower; and (6) conduct long-term bipventing tests (for one year).
The soil gas survey is applicable to shallow sites (3-4 m), since it is useful only if the probes penetrate to treatment
depths. Soil sampling, part of the site characterization, tests for total petroleum hydrocarbon, BTEX, total
phosphorous and Kjeldahl nitrogen, iron, moisture, particle size, pH, and alkalinity. Optimal pH is in the 5-9 range;
alkalinity may affect apparent respiration rates due to CO2 production. In situ respiration testing measures O2
utilization rates over time together with He loss, which is an indicator of leakage around monitoring points.
Respiration testing compares respiration rates within the contaminated zone to those outside the zone, and measures
the oxygen diffusion out of the area. Results from an in situ respiration test at Johnston Island in the Pacific revealed
a biodegradation rate of 19 mg/kg/day. The radius of influence of bioventing was defined as that area to which
47
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NATO/CCMS Pilot Study II
adequate air can be supplied to meet O2 demand. It is determined by measuring O2 after equilibrating pressure
changes.
BTEX compounds were the most significant contaminant, but most sites had <1 mg/kg. No clear pattern emerged
from initial and one-year measures of soil BTEX concentrations. Aeration was found possible at most sites (90%),
and biological respiration was observed at all sites. Inorganic nutrients (such as nitrogen) were usually present in
ambient concentrations enough that feeding was unnecessary. Site limitations that affected bioventing success include
high moisture content in the soil, inadequate permeability, and temperature. The most significant problem was
permeability, which was also related to soil moisture content. Cleanup levels were not determined.
"Danish Assistance in the Remediation of Tokol Airbase" (1994) Jens Nonboe Andersen, Ramb0Il,
Hannemann & Hojlund, Virum, Denmark
Large quantities of free-phase jet fuel have been recovered from Tokol, considerably reducing the health risk posed
by the contamination to nearby well fields. However, free-phase product cannot be recovered completely, and
adsorbed contaminants in the unsaturated zone contribute to on-going threats to public health. Successful pilot-scale
demonstration of an in situ bioventing system at the site resulted in the decision to proceed with full-scale in situ
remediation.
T5k61 Airbase, located 20 km south of Budapest, was occupied by the Soviet military from the late 1940s to mid-
1991. Hungarian environmental authorities became aware of extensive soil and groundwater contamination at the
facility (see page 14). Contamination was primarily jet fuel in four discrete zones. Free-phase contamination in one
zone alone covered a volume of over 2,000 m3.
Since the fall of 1991, the Danish EPA has been assisting the Hungarian Ministry for Environment and Regional
Policy in conducting site investigations and remedial response to the contamination. The most significant phase of
the assistance, following emergency intervention and logistical support, has five components: (1) risk assessment
of the consequences of the contamination to the potential impact on human health and to determine appropriate
remedial actions; (2) control and recover the free-phase jet fuel and minimize further contamination or dispersion;
(3) monitoring trends over time of the free-phase as well as soil and groundwater contaminants; (4) modeling
groundwater flow and contaminant transport and dispersion in three dimensions in order to predict contaminant
migration to the Danube River (12-18 years) and to the nearby well fields (6-12 years); and (5) demonstrate a pilot-
scale system for biological in situ remediation of the contamination at the airbase, and design scale-up parameters
for full-scale remediation.
48
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NATO/CCMS Pilot Study II
NATO/CCMS FELLOWS
Germany
Portugal
Turkey
United Kingdom
• Hans-Joachim Stietzel, Federal Ministry for the Environment, Blonn. Innovative Approaches
Used on Large Remediation Projects in Germany.
After German reunification, the Federal Government gave the new Laender of Germany (the
new states of Mecklenburg-Western Pommerania, Berlin, Brandenburg, Saxony-Anhalt
Saxony, and Thuringia) the opportunity to establish an exemption clause that removes the
liabilities of owners or investors of commercial properties from environmental damages caused
prior to July 1, 1990, at the discretion of the responsible state government. The purpose of
the exemption clause is to accelerate economic development in the new Laender by removing
some of the problems to potential investors of contaminated land. Exemption may be granted
after the interests of the purchaser, the general public and (he environment have been
considered. Approximately 69,000 applications for exemption have been made. Financing the
remediation of contaminated sites in the new Laender was agreed to in December 1992 by the
Federal Government and the new German states. In cases where the site owner has been
exempted from the liability of environmental damage the costs of remediation will be shared
by the Federal Government (60% share) and the new Laender (40% share). A budget of DM1
billion per year for ten years has been committed to these projects. The objective of this
fellowship is to review and monitor experiences with large remediation projects in the new
Laender. Examples of such projects include the remediation of 50 ha site at Rositz, Thuringia
which is contaminated by phenols, PAH's, BTEX-aromatics, and aliphatic hydrocarbons The
site had been used between 1917 and 1990 for the processing and conversion of 17 5 million
metric tons of lignite tar and 9 million metric tons of crude oil into petroleum products There
are 19 such large remediation projects documented throughout all six of the new German
states.
• Maria Teresa Chambino, INETI, Lisbon, and Maria Jose Macedo, Institute of Materials
Science, Oeiras. Review of the Contaminated Land Situation in Portugal.
An on-going study by the Institute of Environmental Technologieis (INETI) is examining soil
contamination arising from the use of coke ovens and its potential for remediation The first
phase of the work has involved quantifying the total area of contamination and the range of
concentrations of contaminants present within the soils at these sites. In particular, a detailed
characterization of the organic contaminants present in the soils is being conducted along with
an evaluation of the bioremediation of this contaminated material. Site investigation has
revealed high concentrations of polycyclic aromatic hydrocarbons (PAHs) and cyanides within
the site soils.
Resat Apak, Istanbul University, Istanbul. Sorption/SoUdification of Selected Heavy Metals
and Radionuclides from Water. See pages 18, 46
Michael Smith, Clayton Environmental Consultants, Ltd, Berkhamsted. Code of Practice and
Quality Management of Project Reports to Assist Compilation of the Pilot Study Final Report.
The Phase H Pilot Study will produce a final report after its conclusion in 1997. This fellow-
ship will coordinate the organization, technical consistency, and. quality assurance of the
various chapters that constitute the final report. At the Oxford meeting in September 1994
committees were formed to develop working instructions for authors and principal investigators
to follow in the preparation of draft and final reports.
Robert M. Bell, SGS Environment, Liverpool. Review of Quality Assurance and Control
Systems Used by the Individual Projects. \
49
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NATO/CCMS Pilot Study II
United States
Mary Harris, Clayton Environmental Consultants, Ltd, Berkhamsted. Costs of Remediation
and Implications for Technology Transfer.
The systematic collection of economic information on remediation technologies is critical for
the wider application and acceptance of technically proficient technologies Further, such data
would allow a comparative assessment of alternative technologies of sirmlar technical
capability and improve the effective transfer of technologies across international borders. The
objectives of this project are to identify the most sensitive cost elements according to the
economic conditions of the host country and to develop a framework that differentiates these
elements. This framework will'be assessed using demonstration project data to produce a
report on the implications of cost for technology transfer. ,
Domenic Grasso, University of Connecticut, Storrs, Connecticut. Why Some Emerging
Technologies Fail at Hazardous Waste Sites.
The objective of this project is to discover the fundamental reasons why many emerging
technologies fail at hazardous waste sites. It will focus on the air sparging technology. Air
sparging tends to channel through soil pores with the largest radius, whether the system is
pulsed or not. Hence the distribution of air in the sparged zone is not uniform and difficult
to predict. ;
50
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NATO/CCMS Pilot Study II
NATIONAL CONTACTS
Pilot Study
Directors
Walter W. Kovalick, Jr., Ph.D.
Technology Innovation Office
U.S. Environmental Protection Agency
401 M Street, SW (5102W)
Washington, DC 20460
United States
tel: 703-308-8800
fax: 703-308-8528
Volker Franzius
Umweltbundesamt
Bismarckplatz 1
D-14193 Berlin
Germany
tel: 49/30-8903-2496
fax: 49/30-8903-2285
Stephen C. James
Risk Reduction Engineering Laboratory
U.S. Environmental Protection Agency
26 West Martin L. King Drive
Cincinnati, Ohio 45268
United States
tel: 513-569-7877
fax: 513-569-7680
Co-Directors
Esther Soczo
RIVM/LAE
P.O. Box 1
Antonie van Leeuwenhoaklaan 9
3720 BA Bilthoven
The Netherlands
tel: 31/30-743-065
fax: 31/30-293-651
Country Representatives
Ian Lambert
Environmental Protection Agency
40 Blackall Street
Barton Act 2600 Canberra
Australia
tel: 61/6-274-1696
fax: 61/6-274-1230
Harald Kasamas
Federal Ministry of Environment, Youth and Family
Untere Donaustrasse 11
A-1020 Vienna
Austria
tel: 43/1-21132-5315
fax: 43/1-21132-5020
Jacqueline Miller
Institut de Sociologie
GEHAT
Universite Libre de Breuxelles
44 Avenue Jeanne
1050 Bruxelles
Belgium
tel: 32/2-650-3183
fax: 32/2-650-3189
George Hill
Environment Canada
Unit 100
Asticou Centre
241 Cite des Jeunes Blvd.
Hull, Quebec K1A OH3
Canada
tel: 819-953-8718
fax: 819-953-4705
Inge-Marie Skovgaard
Danish Environmental Protection Agency
Waste Deposit - Groundwater Division
29 Strandgade
DK-1401 Copenhagen K
Denmark
tel: 45/3-266-0100
fax: 45/3-296-1656
Rene Goubier
Polluted Sites Team
ADEME
B.P. 406
49004 Angers Cedex 01
France
tel: 33/41-204-120
fax: 33/41-872-350
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NATO/CCMS Pilot Study II
Volker Franzius
Umweltbundesamt
Bismarckplatz 1
D-14193 Berlin
Germany
tel: 49/30-8903-2496
fax: 49/30-8903-2285
R<5bert Reiniger
National Authority for the Environment
Alkotm6ny ut. 29
H-1054 Budapest
Hungary
tel: 36/1-201-1725
fax: 36/1-201-4282
Esther Soczd
RIVM/LAE
P.O. Box 1
Antonie van Leeuwenhoaklaan 9
3720 BA Bilthoven
The Netherlands
tel: 31/30-743-065
fax: 31/30-293-651
Raymond Salter
Resource Management Directorate
Secretary for the Environment
Ministry for the Environment
84 Boullcott Street
P.O. Box 10362
Wellington
New Zealand
tel: 66/4-473-4090
fax: 66/4-471-0195
Scmund Haukland
Norwegian Pollution Control Authority
P.O. Box 8100 Dep
Sr0msveien 96
N-0032 Oslo
Norway
tel: 47/22-57-34-00
fax: 47/22-67-67-06
Branko Druzina
Institute of Public Health
Trubarjeva 2-Post Box 260
6100 Ljubljana
Slovenia
tel: 386/61-123-245
fax: 386/61-323-955
Ingrid Hasselsten
Environmental Protection Agency
17185 Solna '
Sweden ;
tel: 46/8-799-1444
fax: 46/8-799-1222
Urs Ziegler
Federal Office of the Environment, Forests, and
Landscape
Federal Department of the Interior
Buwal Laupenstrausse 20
3003 Berne
Switzerland
tel: 41/31-322-9338
fax: 41/31-382-1546
M. Resat Apak
Professor of Analytical Chemistry
Istanbul University
Avcilar Campus
Faculty of Engineering
Istanbul 34840 :
Turkey
tel: 90/1-5911-996
fax: 90/1-5911-997
Judith Denner
Contaminated Land and Liability Division
Department of the Environment
A228 Romney House
43 Marsham Street
London SW1P 3PY
United Kingdom
tel: 44/71-276-8348
fax: 44/71-276-8403 ;
Walter W. Kovalick, Jr. '.
Technology Innovation Office
U.S. Environmental Protection Agency
401 M Street, SW (5102W) '
Washington, DC 20460
United States '
tel: 703-308-8800 :
fax: 703-308-8528
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