Aerobic Cometabolic Treatment of Chlorinated Aliphatic Hydrocarbons using iSOC® Technology
In aerobic cometabolic bioremediation indigenous bacteria or bioaugmented strains are stimulated by adding oxygen and a cometabolic growthsubstrate to trigger the production of enzymes that can oxidize or degrade the targetpollutant via cometabolism. An iSOC® system is used to deliver oxygen as a terminalelectron acceptor along with a gaseous growth substrate, typically an alkane gas, in aprocess known as Co-infusion to stimulate complete in situ contaminant destruction. The method is most useful for bioremediation of pollutants that are not themselves good aerobic growth substrates for bacteria. Cometabolic treatment has been found to be particularly effective for the chlorinated solvent trichloroethylene (TCE) and other lower or less oxidized chlorinated aliphatichydrocarbons (DCE, VC, TCA, DCA, CF, and MC). At some sites with mixed groundwater contaminants (i.e. petroleum hydrocarbons with chlorinated solvents), the necessary substrate for inducing aerobic cometabolism of the target pollutant may already be present and all that is needed is the infusion of oxygen. Various aliphatic and aromatic hydrocarbon compounds have been found to function as cometabolic treatment substrates and significant research and development has focusedon the use of alkane gases (i.e. methane and propane) for the purpose.