Modelling of anaerobic dechlorination of chloroethenes for in situ bioremediation

A model has been developed that can describe and predict the performance of the bioremediation of tetrachloroethene (PCE) under anaerobic conditions. The observed transformation of chloroethenes could be described by incorporating competitive dechlorination of tetrachloroethene and trichloroethene (TCE) by one type of micro-organisms and assuming rate-limited linear sorption. Laboratory soil column tests in combination with model calculations suggest that formate is used directly as an electron donor by the dechlorinating biomass, but methanol was converted into products (e.g. hydrogen and acetate) which were the actual electron donor(s). Dechlorination in the methanol-fed soil column could only be described assuming the conversion of methanol to be rate determining.