United States
Environmental Protection
Agency
Research And
Development
(RD-672)
EPA 600-N-92-014
August 1992
kvEPA Science Notes
ORD Studies New Way To Deliver
Cleanup Agents
Mobile homes for contaminant-fighting bacteria?
That could be one way of describing a new process
being studied by EPA's Office of Research and
Development (ORD) for storing and releasing
microorganisms to clean up hazardous waste and
prevent pollution
The technique is encapsulation, and scientists in
ORD's Gulf Breeze, Fla, Environmental Research
Laboratory think it has potential for enhancing the
ability of certam types of bacteria, fungi, and other
minute life forms to convert toxic organic
compounds into simpler, non-hazardous materials
through biochemical reactions
Encapsulation involves surrounding a
microorganism with an environmentally safe
polymer material, and then dehydrating it. The
resulting product "looks like crumbly powder, in
odd shapes and sizes," according to Hap Pritchard,
chief of Gulf Breeze's Microbial Ecology and
Biotechnology Branch.
Already used in agriculture for controlled
release of pesticides, encapsulation could offer
severed valuable features for bioremediation and
pollution prevention:
•	Pollution-fighting microorganisms could be
conveniently transported and stored. Preliminary
studies show that cells encapsulated in a polyvinyl
alcohol material have a shelf life of about two
months
•	Release of the microorganisms could be controlled
for maximum effectiveness For example, the cells
could be applied to pesticide-treated fields, and
would remain inactive while the pesticides
functioned to protect crops However, if heavy rams
came, creating the potential for the pesticides to
leach into soil and groundwater, the shell material
would dissolve, freeing the microorganisms to block
contamination
• The microorganisms could be co-encapsulated
with nutrients that would enhance their activity.
Thus, these additives could be specially used for the
added microorganisms, out of the reach of indige-
nous, competitive organisms.
Preliminary small-scale tests at Gulf Breeze have
shown promising results for degradation of toxic
2,4-D Further laboratory studies simulating field
conditions are planned.
(Hap Pritchard, Microbial Ecology and Biotech-
nology Branch, Gulf Breeze ERL, (904) 934-9260)
ORD, DOE Collaborate On
Portable Toxics Monitor
EPA's Office of Research and Development (ORD)
and the Department of Energy's Oak Ridge Nation-
al Laboratory m Tennessee have collaborated to
develop a portable analytical device to speed clean-
ups at hazardous waste sites and leaking under-
ground storage tank sites.
One way of using the device, called a synchro-
nous luminescence (SL) monitor, is to attach a fiber-
optic probe for on-site analysis of organic contami-
nants The monitor, which is battery-powered and
about the size of a small suitcase, can be carried to
the field and can provide on-site readings of fluo-
rescent toxic or hazardous organic compounds, such
as polyaromatic hydrocarbons (PAHs) or polychlori-
nated biphenyls (PCBs) even at levels as low as
parts per billion.
Clean-up of a waste site begins with the process
of analyzing samples from the site to identify the
"hot spots" where the most hazardous wastes occur
in the largest amounts, allowing those parts of the
site to be cleaned up first Under conventional

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methods, soil and water samples are taken from the
site and analyzed at a laboratory to provide that
information.
The SL monitor makes that activity faster and
simpler because:
•	The monitor, a field screening instrument, can
immediately analyze water samples on-site, reduc-
ing the number of samples that need to be sent to
a laboratory for analysis. A quick micro-extraction
step also readies soil samples for on-site analysis.
•	Under conventional methods, samples are sent to
the laboratory, but the analytical information may
not be available for several weeks. As a field screen-
ing instrument, the SL monitor provides immediate
analysis that helps to identify the location of the
hazardous waste "hot spots," so that cleanup can
begin at once. After the cleanup operation, samples
may be taken for more accurate laboratory analysis
to confirm the effectiveness of the hazardous waste
removal.
The SL monitor was developed by Tuan Vo-
Dinh, group leader of the Advanced Monitoring
Development Group, Health and Safety Research
Division, Oak Ridge National Laboratory, with
major funding by ORD. The product will be manu-
factured and commercialized by Environmental
Systems Corp., Knoxville, Tenn.
(Contact William H. Engelmann (702-798-2664)
or Charlita G. Rosal (702-798-2179), Advanced
Monitoring Systems Division, Environmental Moni-
toring Systems Laboratory.)
Upcoming Meetings:
•	"National Technology Initiative: Environmei
Technology Workshops": Sept. 3-4, Las Vegas, Nt..
(Denise Gaffey, 617-674-7317); Sept. 9-10, Cincinnati,
Ohio (Susan Brager, 617-674-7347); Sept. 29-30
Research Triangle Park, N.C. (Elaine Brenner, 617-
674-7334).
•	"Fourth Forum on Innovative Hazardous Waste
Treatment Technologies: Domestic and Internation-
al," Nov. 17-19,1992, San Francisco, Calif. Contact:
SAIC, Technology Transfer Dept., 501 Office Center
Dr., Suite 420, Ft. Washington, Pa. 19034; (215) 542-
1200, or FAX (215) 542-8567.
New Publications:
The following publications are available from the
EPA Center for Environmental Research Informa-
tion, Cincinnati, OH 45268; (513) 569-7562:
"Selected Alternative and Innovative Treatment.
Technologies for Corrective Action and Site Reme-
diation (A Bibliography of EPA Information Re-
sources): Update" (EPA/542/R-92/004).
"Environmental Research Brief: Waste Reduction
Activities and Options at a Printer of Forms and
Supplies for the Legal Profession" (EPA/60T
92/003).

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