LABORATORY FEASIBILITY STUDIES ON BIOLOGICAL INSITU TREATMENT OF A SANDY SOIL CONTAMINATED WITH CHLORINATED ALIPHATICS

Laboratory batch and column experiments have been performed to evaluate the feasibility of obtaining in-situ biodegradation of chlorinated aliphatics in unsaturated soil by in-situ injection of methane and air for stimulation of methane-oxidizing bacteria. Biodegradation of trichloroethylene and 1,1,1-trichloroethane was observed, but tetrachloroethylene did not degrade. One soil contained inhibitory concentrations of chlorinated aliphatics, resulting in long lag-phases and slow methane degradation rates. In full scale stripping and leaching are expected to contribute significant compound removal processes, making bioremediation a less attractive method at the currently obtained degradation efficiencies.