Investigation of the transport behaviour of selected organic compounds at the electrochemical remediation of contaminated soils

Electrochemical procedures have been successfully applied to the decontamination of soils even from organic substances in last few years. Feasibility and duration of electrochemical remediation procedures depend on several parameters. Lab scale experiments in the run-up to a real soil decontamination treatment can help to determine and evaluate the influence of the most important parameters and can support in searching optimal remediation conditions. A special semi-automatically operating experimental setup was developed and applied to investigate the transport behaviour of pollutants in soils without sampling. The transport of bromophenol in different kinds of soils at several electrical field conditions was investigated. For these investigations, a small part of bromophenol was labelled with radioactive nuclide 82Br. A procedure of the synthesis of labelled bromophenol from phenol and irradiated ammonium bromide in a single step was developed. The experimental results for remediation of the investigated soils have shown that, generally, the transport of bromophenolate ions occurred towards anode direction. In some cases, a transport towards the opposite direction was proven during the first trial period. From the results, transport velocities could be calculated. The knowledge of transport behaviour and velocities is needed for the planning of real decontamination processes and to predict the necessary remediation duration. (author)