The environment has been exposed to a number of hazardous chlorinated
organic compounds. These compounds may be anaerobically biotransformed by
sequential reductive dechlorination reactions in which the chlorine atoms are
replaced with hydrogen atoms. Because reductive dechlorination processes may
occur very slowly in the environment and chlorine position affects the...
A Langmuir sorption model incorporating a second step of
irreversible absorption was applied to a model soil system. The column
was packed with cellulose triacetate; pulse and step input tests with
3,4-dichlorophenol were performed; the effluent concentration was
measured by electron capture detector gas chromatography and sorption
rate constants were...
The methane monooxygenase (MMO) enzyme, used by methylotrophs
to oxidize methane, has been shown to possess quite broad substrate
specificity, being able to oxidize many organic compounds including
n-alkanes, n-alkenes, ethers, and aromatic, alicyclic, and
heterocyclic compounds. In this research, it was sought to
determine whether a gas-permeable-membrane-supported (GPMS) biofilm...
A gas-permeable-membrane-supported (GPMS) biofilm consisting
of methylotrophic bacteria was effective in degrading chlorinated
methanes, ethanes, and ethenes. The biofilm was developed on a
gas-permeable fabric (Goretex, W.L.Gore & Associates, Elkton,
Maryland) that divided a reactor vessel into a liquid compartment
and a gas compartment. Goretex is a nylon-backed teflon mesh...
A continuous flow, gas-permeable-membrane-supported (GPMS) biofilm
reactor was developed to facilitate the treatment of polychlorinated
biphenyls (PCBs). The GPMS biofilm reactor consisted of a cylindrical
glass vessel made up of three compartments: the gas, liquid and
headspace compartments. A gas-permeable membrane separated the bottom
gas compartment from the liquid compartment....
The biodegradation of five polychlorinated biphenyls (PCBs) by
Hudson River and Silver Lake sediments was studied using gas
chromatography with electron capture detection (GC/ECD) and gas
chromatography with mass spectrometry (GC/MS) analyses. Methanogenic
sediments from the Hudson River and Silver Lake were used to inoculate
four anaerobic filter reactors. The...
Knowledge of a compound's degradation pathway is crucial to the assessment of risk at contaminated sites. Pentachlorophenol and its metabolic products can serve as model compounds to study the fate and transport of halogenated aromatic compounds in the environment. Acclimation of anaerobic sewage sludge to pentachlorophenol produced a microbial consortium...
In situ bioremediation of pentachlorophenol-contaminated ground water in a sequential anaerobic-aerobic down borehole permeable barrier reactor requires a non-toxic primary substrate for dichlorophenol cometabolism. Serum bottle tests comparing the effectiveness of eight primary substrates for aerobic dichlorophenol degradation showed phenol to be the most effective followed by imitation vanilla flavoring,...