Deponiegas

Investigations were performed concerning whether or not the composition of volatile halogenated carbons in landfill gas (LFG) change when they uncontrolledly leave the aerobic surface of landfill. For this reason, the aerobic biological degradation of chlorofluorocarbons (CFCs), chlorofluorohydrocarbons (HCFCs), and vinyl chloride (VC), which were often measured in LFG of old household-landfills, was investigated. In 1-liter and 126-liter laboratory test reactors, the aerobic milieu conditions of the surface of landfills were simulated. Air with methane and trichlorofluoromethane (R11), dichlorodifluoromethane (R12), and their reductive metabolites dichlorofluoromethane (R21), chlorodifluoromethane (R22), and vinyl chloride (VC) were continuosly pumped through marl and a mixture of biowaste and compost. R21, R22, and VC were degraded, probably cometabolically by methanotrophic bacteria. They have inhibited the methane oxidation. The degradation rates of R21 (only in biowaste and compost) and R22 were up to 2.8 and 10 mg/m³ _material/h, respectively. The maximum degradation rate of VC was 1,3000 mg/m³ _material/h in marl. Under aerobic milieu conditions, a biodegradation of R11 and R12 was not detected.