Chlorinated hydrocarbons derived from chlorinated pesticides, herbicides and wood preservatives are the most frequent persistent pollutants in Hungary.

The research project aimed at developing a microbiological reductive dehalogenating process and the bench scale optimisation of the technology.

For the on site treatment of the soil an anaerobic bioreactor was developed heated by sun collector, furnished with recirculating leachate dissipater and process control devices. Anaerobic conditions were generated by the application of amendments. A field pilot test of the developed process was performed when co-operating in an emergency case and 7.5 t excavated soil contaminated with 2-chlorotoluene in mean concentration as high as 300 mg/kg was treated.

The technology proved to be effective, complete mineralization was achieved.