Laboratory feasibility studies on biologicalin‐situtreatment 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.