SUMMARY REPORT


HIGH-PRIORSTY          O^ B8OR1MEDIATION
       BIOREMEDIAT1ON RESEARCH

           NEEDS WORKSHOP

              April 15-16,1991

              Washington, DC
            v/EPA
     U.S. Environmental Protection Agency

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                                  EXECUTIVE SUMMARY


       At the request of the EPA Bio re mediation Action Committee, a workshop was held on April
15 and  16, 1991 to propose high priority topics  for  research to further advance bioremediation
technologies.   Forty-five scientists, engineers,  and  research administrators from governmental
agencies, industry,  and academia participated.  The  participants proposed four  major areas for
research:

       I.   Determining factors governing  the availability of pollutants  for bioremediation and
           devising ways to increase their availability for destruction.

       2.   Improving the design of processes for bioremediation.

       3.   Overcoming problems associated with scale-up from simple laboratory systems to field
           operations.

       4.    Developing innovative and novel bioremediation processes.

       The results of  the  research  should greatly  expand the utility  and  scope  of use  of
bioremediation for the clean-up of contaminated waters, soils, and aquifers.

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                   HIGH-PRIORITY RESEARCH CH BIOREMEDIATION
                                 REPORT OF WORKSHOP
                                     April 15-16, 1991
I.  INTRODUCTION

       The Environmental Protection Agency (EPA) sponsored an EPA-Industry Meeting on the
Environmental Applications of Biotechnology on February 22, 1990. The purpose of the meeting
was  to  discuss ways  to apply bioremediation  technologies  to  solving  problems arising  from
environmental pollution with chemicals.  As a result of that meeting, EPA formed a Bioremediation
Action Committee (BAC) and established six subcommittees of BAC to facilitate further development
of the technologies.  Dr. John H. Skinner, Deputy Assistant Administrator of-EPA for Research and
Development, was named as BAC  chair.

       The BAC recommended that 
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       Many conferences and workshops have been held on bioremediation and biodegradation. The
participants in several of these meetings formulated recommendations for research needs. However,
the purposes of these meetings were  rarely the establishment of  the research needs of highest
priority, and recommendations emanating  from those meetings, although important, do not address
solely  the  major  limitations  to  the  rapid  introduction of  new  approaches to  bioremediation.
Nevertheless, those lists  of research needs often contain many of the recommendations presented
here.  To facilitate the development of recommendations by the EPA-sponsored workshop and to
provide a clear focus to its deliberations, the organizers of the workshop provided  the participants
with the recommendations from these previous conferences and, in addition, comments  from several
individuals and groups.


II.  CONTEXT OF THE RESEARCH PRIORITIES

       A number of issues addressed at the workshop are appropriate as an introduction to the high-
priority research needs.  These issues need to  be stated explicitly to provide a meaningful context for
the ultimate use of the information obtained from the research that is recommended.

       Both short- and long-term investigations are essential.  Some of the major issues indicated
below  will  be  resolved  reasonably  readily,  and  the information will quickly  contribute  to
bioremediation in  the field.   Answers to  some of  the other issues  will  take more time, but
information on those subjects is no less important.  It would be imprudent to support only research
on topics that will provide  a short-term payoff,  because the other information gaps will still exist
at the completion of the short-term research: A prudent approach would involve providing adequate
financial support for research that is designed to bring some bioremediation technologies to practical
utility soon, as well as funding for research that will provide the  information needed to develop
technologies  for  which  the  current state of information is inadequate.  A  balance should be
maintained between research for technologies that will be useful in the near future and those that
will solve the more difficult problems.

       Implicit  in  our  statement of  research  needs is the  assumption that the  identities  and
concentrations of the products of bioremediation will be determined. This information is required
to serve as a basis for determining the transport, fate, and possible toxicity of the chemical products
generated as a result of bioremediation.

       Research designed to establish  better bioremediation technologies should be coupled with
economic analyses of  these technologies and economic comparisons of bioremediation with other
means for ridding the environment of pollutants.

       The information gained from the research proposed herein ultimately must be considered in
the context of specific sites of contamination. Thus, the appropriate bioremediation technology for
a given site may involve either in-situ  approaches or above-ground bipreactors.  The  remediation
may be  best carried out  by an aerobic or  anaerobic process, or a particular  pollutant, mixture of
contaminants or site characteristics may dictate that an innovative process be developed.

       The  priorities  for research apply to  both organic and  inorganic contaminants. Although
much of the put research on bioremediation has focused on organic materials, sites contaminated
with inorganic substances, including metallic ions, may also be remediated biologically by oxidizing
or reducing  inorganic contaminants to nontoxic forms or by immobilizing or retaining these
pollutants in a fashion that the exposure of sensitive species is reduced or that the  product can be
removed from the site.

       Biological processes for remediation will often not work  alone.  They  may  need to be
combined with  other treatment technologies to ensure effective or  rapid treatment.  The need for
several technologies to be used at  a single site is particularly important for complex wastes.

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       The research needs given below are not presented in terms of relative priorities, but represent
issues for which solutions are essential  in order to have  more effective and more  widely used
biological approaches to remediation of contaminated sites.


III.  HIGH-PRIORITY RESEARCH NEEDS

       A.  Bioavailability

       Many compounds  or  pollutants that are quickly biodegraded under laboratory conditions
persist in the environment.  Attempts to enhance the biological destruction of these compounds often
have limited success because they are not readily available for microbiai destruction in the forms
and physical or chemical states in which they exist at sites of contamination.  Thus, although the
pollutants potentially may  be destroyed by microbiological means,  environmental factors and the
physical or chemical state of the substance prevent its  rapid degradation in  the field by  presently
available  procedures.  This  constraint on bioremediation represents a major  limitation co the
widespread use of many biological technologies.

       •   Sorption/Desorption.  Research should be conducted to determine the role of sorption and
           desorption in   governing the susceptibility of chemicals  at contaminated  sites to
           bioremediation. Methods should be sought to enhance the destruction of compounds or
           materials  whose availabilities are limited because of their sorption  to environmental
           surfaces or their slow desorption  to forms available  for microbiai degradation.

       •   Non-Aqueous  Phase Liquids. Studies are needed to determine the role of non-aqueous
           phase liquids  in  determining  the resistance or slow  degradation  of  compounds  that
           otherwise would  be rapidly destroyed.   Many  pollutants are  present  in non-aqueous
           phase liquids in subsoils, aquifers,  and surface waters,  and compounds in these non-
           aqueous liquids may  be  protected from  rapid  destruction.  Technologies need to be
           developed to enhance the bioremediation of sites containing unwanted chemicals in non-
           aqueous phase liquids.

       •   Matrix Effects. Investigations are required  to determine the role  of the physical matrix
           in which pollutants are found on their susceptibility to biological destruction.  The role
           of diffusion of a chemical from a physically inaccessible site and of tortuosity in polluted
           sites should be clarified. Means to  overcome  problems associated with the physical matrix
           of the waste should be defined.

       •   Weathering/Aging.   The availability of many chemicals for  biological destruction
           diminishes with time. The reasons for the diminished availability of the substances and
           ways to bring about the biological destruction of the resulting weathered pollutants should
           be investigated.

       •   Immobilization and Solubilization. Microorganisms frequently bring about reactions that
           result in immobilization, fixation,  precipitation, or solubilization of organic or inorganic
           compounds or ions.  Such processes may detoxify substances that otherwise would be
           harmful.  Research is required to  further define these processes and to devise practical
           means to exploit them under field conditions.

       •   Limits to  Bioremediation. Research is needed to  determine the physical and  chemical
           reasons why a  biodegradable compound is sometimes not available for biodegradation.

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       B.  Process Design

       Devising practical solutions to existing and future problems of environmental pollution will
require additional  information  on  the  design  and  evaluation  of  specific  approaches  for
bioremediation. A particular technology may appear to be feasible based upon small-scale laboratory
tests, but  many of the proposed processes  are presently not yet suitable for field use and require
further development and optimization.

       Research on process design should focus on both in-situ bioremediation and above-ground
bioreactors, including bioremediation by land treatment and composting.  Except as indicated, the
proposed research refers both  to in-situ bioremediation and above-ground bioreactors.

       •   Factors limiting the  rates of biodegradation should be defined.  Often, the rate of in-
           situ bioremediation or treatment in above-ground reactors can be markedly increased,
           but procedures for increasing the rates require information on the factors limiting those
           rates.

       •   Information  is  required oh-'the operation  and on  the durability  and  stability of
           technologies for in-situ bioremediation  and  above-ground bioreactors.

       •   Means should  be  developed  for  the  more  effective  monitoring  and   control  of
           bioremediation processes and procedures.

       •   New or better models should be-developed for bioremediation processes.  These models
           will permit the design of cost-effective, safe and practical technologies.

       •   Research   should    be  conducted   to  devise   multi-stage   processes--including
           anaerobic/aerobic   transformations,   processes  involving  desorption  followed  by
           biodegradation, and technologies involving chemical followed by biological treatment.

       •   Investigations are needed on processes suitable for the destruction of chemicals present
           at low  concentrations.  A process that is effective at high concentrations of a pollutant
           may not be useful or may not be efficient when the pollutant of concern is at low  levels.

       •   Research is needed on the design of novel processes for bioremediation--including slurry
           reactors, procedures involving vapor-phase treatment, technologies that enhance the rates
           of cometabolism, etc.

       •   Research on process design must be  coupled with enhanced data collection, including
           advanced technologies for data  collection.

       •   Information is required on  the effect of  environmental  heterogeneity   on  in-situ
           bioremediation.

       •   Research should be conducted to determine the  factors affecting the feasibility and the
           extent of in-situ bioremediation.

       •   Studies are required on factors determining the success of microbial  inoculation of
           contaminated sites  and the  mobility and survival of microorganisms added for in-situ
           bioremediation.

       •   A more extensive base of knowledge is required on  mass transport--including delivery
           systems for nutrients (N, P, etc.), electron acceptors  (O2, H2O;, nitrate, and sulfate), and
           electron donors (methane, methanol, etc.) and the mixing of solids, fluids, and chemicals.

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       •   Further understanding is needed on factors limiting microbial populations and activities - -
           including nutrient limitations, the toxicity of waste components to microorganisms, and
           induction of biodegradative activity.

       C.  Scale-Up

       A variety of problems become evident  in attempts to conduct bioremediation in the field
based on simple laboratory evaluations of biodegradation. Research is needed on problems of scale-
up in order to permit effective remediation to be accomplished in the field. The heterogeneity of
sites in the field and scale-dependent transport and transformation processes often complicate facile
extrapolations from small operations in the laboratory to field programs. Issues of mass transport and
modeling are also particularly relevant to problems of scale-up, and are especially relevant to in-
situ bioremediation.

       •   EPA  together with other federal agencies should participate in the development and
           funding of pilot-scale facilities to assure reproducible and rigorous research and to allow
           for practical field-scale designs of bioremediation technologies

       •   Consideration should be given to relaxing permitting requirements  for research at such
           facilities or to allowing access to existing hazardous waste sites.

       •   Further research is required  on microcosms  as simulants  of field conditions.  The
           availability of validated small-scale simulants would facilitate the development of new
           technologies or better evaluations of which  bioremediation technologies will be useful
           under field conditions.

       D.  Innovative and Novel Processes

       Although considerable progress  has been made in  devising procedures for biodegradation,
biotransformation, and bioremediation,  major problems remain.  Hence, an exploratory program is
essential in order that these less tractable problems might be resolved.  Research on these processes,
in some cases, may be completed reasonably quickly, but frequently the needed investigations will
require long-term support, especially for the truly innovative approaches.

       The bioremediation of many complex wastes will  not be simple.  Components of complex
wastes may be toxic and prevent bioremediation, or they may act antagonistically or synergistically
in ways that are now unpredictable.

       •   Novel approaches are required for complex  mixtures in order to remove or reduce the
           toxicity to the organisms responsible for bioremediation or to devise multi-stage processes
           including a phase of biological treatment.

       •   Novel microbial processes should be sought--including cometabolic as well as anaerobic,
           aerobic, and microaerophilic transformations.  Compounds that are only cometabolized
           represent  a special category of concern because many of the current approaches to
           bioremediation are not relevant to such chemicals. Research on novel microbial processes
           should include investigations on the biochemical pathways and metabolic control of the
           biodegradative transformation.

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IV.  PARTICIPANTS IN WORKSHOP
Dr. Daniel A. Abramowicz
Manager, Environmental Technology
  Program
Biological Sciences Laboratory
GE Corporate Research and Development

Dr. Martin Alexander
Professor
Department of Soil, Crop and
  Atmospheric Sciences
Cornell University

Dr. Frederick Archibald
Pulp and Paper Research Institute of Canada

Dr. Ronald M. Atlas                  >'•'
Department, of Biology
University of Louisville

Dr. Steven D. Aust                     :
Biotechnology Center
Utah State University

Mr. Tom Baugh
Environmental Scientist
U.S. Environmental Protection Agency

Dr. Peter Chapman
U.S. Environmental Protection Agency

Ms. Sue Markland Day
Senior  Research Associate
The University of Tennessee-Knoxville

Ms. Kate Devine
Applied Biotreatment Association

Dr. Pat Eagan
Director, Bioremediation Consortia
Biotechnology Center
University of Wisconsin

Mr. Robert D. Fox
IT Corporation

Dr. John Glaser
U.S. Environmental Protection Agency
Risk Reduction Engineering Lab

Dr. D.  Jay Grimes
Ecological Research Division
Office  of Energy Research
U.S. Department of Energy
 Dr. Robert Hickey
 Michigan Biotechnology Institute

 Dr. Peter Holden
 Australian Nuclear Science
  and Technology Organization

 Captain Kevin Keehan
 U.S. Army Toxic  and Hazardous Materials
  Agency (USATHMA)

 Mr. Richard Kibler
 Directorate for Environmental Technology

 Dr. Walter W. Kovalick, Jr.
 Director
 Technology Innovation  Office
 U.S. Environmental Protection Agency

 Dr. Rashalee Levine
 U.S. Department of Energy
 Office of Technology Development

 Dr. Richard G. Luthy
 frofessor and Head
 Department of Civil Engineering
 Carnegie-Mellon University

 Dr. Dale  Manty
 Office of Exploratory Research
 U.S. Environmental Protection Agency

 Dr. John  McCarthy
 Environmental Sciences Division
 Oak Ridge National Laboratory

 Dr. Perry McCarty
 Director
 Western Region Hazardous Substance
  Research Center
 Department of Civil Engineering
Stanford  University

 Dr. Beverly McFarland
Chevron  Research and Technology
  Corporation

 Mr. Terry Mclntyre
 Head, Biotechnology Section
Commercial Chemicals Branch
Conservation and Protection
 Environment Canada

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Mr. James McNabb
U.S. Environmental Protection Agency
Robert S. Kerr Environmental
 Research Laboratory

Dr. Laura Meagher
University Industry Liaison
Agricultural Biotechnology Center
Cook College, Rutgers University

Dr. Henryk Melcer
Wastewater Technology Centre
Environment Canada

Dr. Ronald H. Olsen
Professor of Microbiology
Department of Microbiology        '  :t
University of Michigan Medical School

Dr. P.H. Pritchard
U.S. Environmental Protection Agency
Environmental Research Laboratory

Mr. Kevin Reilly
Acting Chief
Logistics and Operations Division
DL A-Defense National Stockpile Center

Dr. Rejean Samson
Section Head, Environmental Engineering
National  Research Council Canada
Biotechnology Research Institute

Mr. Paul Schatzberg
Taylor Research Center
U.S. Department of the Navy

Mr. Alan Seech
Dearborn Chemical Co.
Wastewater Technology Centre

Dr. Jim C. Spain
U.S. Air  Force Environmental Services
 Center/RDVC
Dr. Hans Stroo
Remediation Technologies, Inc.

Dr. William A. Suk
National Institute of Environmental
 Health Sciences

Dr. James Tiedje
Michigan State University
Center for Microbial Ecology

Dr. C. H. Ward
Professor and Chairman
Department of Environmental Science
 and Engineering
Rice University

Dr. Walter J. Weber, Jr.
Director
Great Lakes and Mid-Atlantic Hazardous
 Substance Research Center
Department of Civil Engineering
The College of Engineering
The University of Michigan

Ms. Beverly Whitehead
U.S. Department of Energy

Dr. John Wilson
U.S. Environmental Protection Agency
Robert S. Kerr Environmental Research
 Laboratory

Dr. Richard E. Woodward
Vice President
ENSR Consulting and Engineering

Dr. R. Campbell Wyndham
Environmental Biology
Carleton University

Dr. Wally Zuk
Director of Environmental  Science Programs
Australian Nuclear Science and Technology
 Organization
Lucas Heights Research Laboratories

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