W Eng

Publications (4)1.94 Total impact

• Article: Methanol suppression of trichloroethylene degradation by Methylosinus trichosporium (OB3b) and methane-oxidizing mixed cultures.

  W Eng, A V Palumbo, S Sriharan, G W Strandberg
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  ABSTRACT: The effect of methanol on trichloroethylene (TCE) degradation by mixed and pure methylotrophic cultures was examined in batch culture experiments. Methanol was found to relieve growth inhibition of Methylosinus trichosporium (OB3b) at high (14 mg/L) TCE concentrations. Degradation of TCE was determined by both radiolabeling and gas chromatography techniques. When cultures were grown on methanol over 10 to 14 d with 0.3 mg/L TCE, OB3b degraded 16.89 +/- 0.82% (mean +/- SD) of the TCE, and a mixed culture (DT type II) degraded 4.55 +/- 0.11%. Mixed culture (JS type I) degraded 4.34 +/- 0.06% of the TCE. When grown on methane with 0.3 mg/L TCE, 32.93 +/- 2.01% of the TCE was degraded by OB3b, whereas the JS culture degraded 24.3 +/- 1.38% of the TCE, and the DT culture degraded 34.3 +/- 2.97% of the TCE. The addition of methanol to cultures grown on methane reduced TCE degradation to 16.21 +/- 1.17% for OB3b and to 5.08 +/- 0.56% for JS. Although methanol reduces the toxicity of TCE to the cultures, biodegradation of TCE cannot be sustained in methanol-grown cultures. Since high TCE concentrations appear to inhibit methane uptake and growth, we suggest the primary toxicity of TCE is directed towards the methane monooxygenase.
  Applied Biochemistry and Biotechnology 02/1991; 28-29:887-99. · 1.94 Impact Factor
• Conference Proceeding: Effects of diverse organic contaminants on trichloroethylene degradation by methanotrophic bacteria and methane-utilizing consortia

  A.V. Palumbo, P.A. Boerman, S.E. Herbes, W. Eng, G.W. Strandberg, T.L. Donaldson
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  ABSTRACT: Groundwater contaminated with organic compounds, especially solvents such as benzene, trichloroethylene (TCE), perchloroethene (PCE), carbon tetrachloride, and chlorinated ethanes, is a problem at many US Department of Energy facilities including the Oak Ridge National Laboratory (ORNL). Regulations require consideration of alternatives for remediation of these sites. A demonstration project was initiated in the spring of 1990 that will permit evaluation of two cometabolic approaches to remediation of groundwater and may lead to remediation alternatives that prove both more effective and less costly than traditional methods. More generally, the demonstration will provide valuable information on the applicability of bioremediation to a groundwater contamination problem at numerous DOE sites. The purpose of this research is to examine the effects of contaminants commonly found in association with TCE at DOE sites and to determine the conditions required for maximizing TCE degradation rates. This study focuses on compounds found in a seep at the ORNL K-25 site. The research presented here details initial experiments on TCE degradation by methanotrophs conducted in the presence of a synthetic medium, TCE, and one or more contaminants found at the K-25 site. Formate has been reported to increase the rate of TCE degradation by pure cultures but had not been tested with mixed cultures. As part of the effort to maximize TCE degradation rates, we examined the effect of formate on degradation by a mixed culture. 5 figs., 1 tab.
  12/1990
• Article: The use of methanotrophic bacteria for the treatment of groundwater contaminated with trichloroethene at the US Department of Energy Kansas City Plant

  S.B. II Garland, A.V. Palumbo, G.W. Strandberg, T.L. Donaldson, L.L. Farr, W. Eng, C.D. Little, Tennessee Univ., Knoxville, TN, Florida State Univ., Tallahassee, FL
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  ABSTRACT: This study was conducted to demonstrate the technical feasibility of a trickle-filter methanotrophic bioreactor for the remediation of trichloroethene (TCE) contamination in groundwater. A bench-scale continuous-flow bioreactor was constructed and operated for several months to treat synthetic contaminated groundwater and to identify the rate of TCE degradation and the parameters that control bioreactor performance. With influent concentrations of TCE and trans-1,2-dichloroethene (DCE) of 1 mg/L each and a residence time of 50 min, approximately 50% of the TCE and 90% of the DCE were degraded in a single pass through the bioreactor. Further degradation of TCE was obtained with liquid recycle. The performance of the bench-scale bioreactor indicates that bioremediation of TCE-contaminated groundwater is technically feasible. A 3-month pilot plant project to further develop the process is estimated to cost approximately $180,000. A full-scale plant ranging in size from 50 to 700 gal/min is estimated to cost from $180,000 to $1 million to construct and from $4 to $1 per 1000 gal to operate.
  10/1989;
• Conference Proceeding: Degradation of trichloroethylene and trans-1,2-dichloroethylene by a methanotrophic consortia in a trickle-type bioreactor

  G.W. Strandberg, T.L. Donaldson, L.L. Bolla, A.V. Palumbo, W. Eng
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  ABSTRACT: A trickle-bed bioreactor containing a consortium of microorganisms utilizing methane as the primary carbon source was used to treat a synthetic groundwater containing trichloroethylene (TCE) and trans-1, 2-dichloroethylene (DCE). With influent concentrations of TCE and DCE of 1 mg/L each and an average residence time of about 50 min, >50% of the TCE and >90% of the DCE was degraded. The reactor exhibited first-order kinetics with respect to TCE degradation. 5 refs., 1 tab.
  12/1987