Demonstration Bulletin: Metal-Enhanced Abiotic Degradation Technology, Environmental Technologies, Inc.

&EPA
United States
Environmental Protection
Agency
EPA/540/MR-95/510
May 1995
SUPERFUND INNOVATIVE
TECHNOLOGY EVALUATION
Demonstration Bulletin

Metal-Enhanced Abiotic Degradation Technology

EnviroMetal Technologies, Inc.
Technology Description: EnviroMetal Technologies, Inc. (ETI),
of Guelph, ON, Canada, has developed the metal-enhanced
abiotic degradation technology to treat halogenated volatile organic
compounds (VOC) in water. A reactive, zero-valent, granular iron
medium causes reductive dehalogenation of VOCs yielding simple
hydrocarbons and halogen salts as byproducts. The ETI technology
can be installed and operated aboveground in a reactor, or in situ,
as a continuous wall or a "funnel and gate" system.

The SITE Program evaluated an aboveground reactor for
remediation of groundwater from the SQL Printed Circuits site in
Wayne, NJ over 3 mo during 1994 and 1995. Based on ETI's
laboratory studies, the technology was designed to lower chlorinated
VOC concentrations below regulatory limits after one pass through
the reactive iron medium.

The aboveground reactor design may be used to simulate the
treatment process at pilot scale, allowing for measurement, control,
modification, and optimization of design and operating parameters,
or may be operated as a stand-alone treatment unit. Figure 1
presents a schematic of the aboveground reactor as demonstrated.
Contaminated groundwater enters the reactor through an air
eliminator, 5-^m water filter (to remove suspended solids which
may inhibit flow through the reactive iron medium), and flow meter.
Water flows by gravity through the reactive iron medium and into
the collector line at the bottom of the reactor, and then exits through
the effluent line. The effluent line is plumbed such that about 2 ft of
influent water remains ponded above the surface of the reactive
iron medium. A passive gas vent in the top of the reactor prevents
accumulation of excess pressure. A manhole with a sightglass
allows observation of the reactive iron surface and access to the
tank interior. The demonstration system included the reactive iron
medium, well sand, a fiberglass reactor tank for the aboveground
installation, and appropriate ancillary groundwater pumps and
piping, where necessary.

Waste Applicability: ETI claims that its system for treating
halogenated VOCs in water is an improvement over conventional
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Figure 1. The metal-enhanced abiotic degradation technology as demonstrated.
Printed on Recycled Paper

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 methods for removing or destroying these contaminants. ETI also
 claims that  its  technology  is applicable to a wide range of
 halogenated VOCs in water; the SITE Program examined only
 chlorinated  solvents,  primarily trichloroethene  (TCE) and
 tetrachloroethene (PCE). ETI further claims that the technology is
 a highly efficient dechlorination  process requiring  minimal
 maintenance and that contaminants are completely dechlorinated.

 Demonstration Results: The primary objectives of  the
 demonstration were  1) to determine whether or not effluent met
 New Jersey  Department of  Environmental Protection (NJDEP)
 and federal maximum contaminant level (MCL) requirements for
 all chlorinated VOCs detected, and 2) to determine the conversion
 efficiency of  PCE and other  chlorinated VOCs. As with all SITE
 Program demonstrations, data were gathered  to evaluate  the
 operating and design parameters, and the costs of using  the
 technology.

 Water samples were collected at influent (11) and effluent (E1)
 locations weekly over 3 mo and analyzed for VOCs. Water samples
 were also collected at 5 points within the reactor (R1 - R5) at
 monthly intervals.  Monthly samples were analyzed  for VOCs,
 metals, chloride, sulf ate, and inorganic carbon. Field measurements
 on all samples included pH,  oxidation-reduction potential or  Eh,
 temperature, specific conductance, and dissolved oxygen.

 Preliminary results indicate that a flowrate of approximately 0.5
 gal/min was  maintained throughout most of the demonstration
 period. About 60,833 gal were treated during 13 weeks of sampling.
          Table  1  displays preliminary influent and effluent contaminant
          concentrations in comparison to regulatory limits. Vinyl chloride
          and cis-1,2-dichloroethene (cDCE) exceeded NJDEP regulatory
          limits during Week 13. This may be due to higher than expected
          levels of PCE in the influent, or channeling through the reactor.
          Conversion efficiency of PCE during the demonstration  period
          exceeded 99.9%. Flow conditions and reaction rates in the iron
          bed may decrease over time due  to precipitation. Complete
          demonstration results including evaluation of precipitation in the
          bed and costs of the technology will be published in a Technology
          Capsule  and an Innovative Technology Evaluation Report which
          will be available late in 1995. The SITE Program will also evaluate
          a field-scale "funnel and gate" design in 1995. These results will be
          available in 1996.

          For Further Information:

          Dr. Chien T. Chen
          EPA SITE Project Manager
          U.S. EPA(MS-104)
          2890 Woodbridge Avenue, Bldg. 10
          Edison, NJ 08837-3679

          Technology Developer:
          John Vogan
          Project Manager
          EnviroMetal Technologies, Inc.
          42 Arrow Road
          Guelph, ON, Canada N1K 1S6
Table 1. Preliminary Influent and Effluent Concentrations and Regulatory Limits

                      Influent (ng/L)                         Effluenta fag/L)

Contaminant       Range           Mean          Range          Mean
                         Limit
 Regulatory Limits (ng/L)

MCL"         NJDEPC
PCE
TCE
CDCE
Vinyl
Chloride
4,100-13,000
54-590
0-1,200"

0
7,962
159
550 e

0
ND
ND
1.3-37

1.2-8.4 '
ND
ND
9.2

4.1
0.9
0.9
0.9

0.9
5
5
70

2
1
1
10

5
Notes:
fig/L  micrograms per liter
ND   Not detected
a     No contaminants detected until Week 9
b     Federal maximum contaminant levels
c   New Jersey Department of Environmental Protection site-specific
    discharge permit standards
d   Not detected until Week 6
e   Mean of non-zero values only
f   Not detected until Week 11
United States
Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, OH 45268

Official Business
Penalty for Private Use
$300
                                               BULK RATE
                                         POSTAGE & FEES PAID
                                                   EPA
                                            PERMIT No. G-35
EPA/540/MR-95/510

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