Effects of trace volatile organic compounds on methane oxidation

The effects of volatile organic compounds (VOCs) on methane oxidation in la ndfill cover soils were examined. The batch experiments were conducted usin g single and mixed VOCs, such as, dichloromethane (DCM), trichloroethylene (TCE), tetrachloroethylene (PCE), and benzene. The results from all combina tions showed a decrease in methane oxidation rate with increase in VOC conc entrations. Moreover, inhibition effects of TCE and DCM were found higher t han benzene and PCE. The reduction of methane oxidation kv benzene and PCE could be attributed to the toxicity effect, whereas TCE and DCM were found to exhibit the competitive-inhibition effect. When the soil was mixed with DCM, no methane oxidation was found. Damage to the cell's internal membrane was found in a methanotrophic culture exposed to VOC gases which is the at tachment site of a key enzyme needed for methane oxidation.