Ecology & Safety, Volume 11, 2017

Abstract: Chemical industries produce large amounts of short-chain halogenated aliphatic hydrocarbons, which are used as organic solvents, paints, pesticides, herbicides and intermediates for the synthesis of other organic compounds. Significant quantities of 1,2-dichloroethane (1,2-DCA) have been produced over recent years. Due to toxicity and carcinogenity of this chemical a vast scientific interest has focused on its removal from polluted water. The effect of constant electric field for 1,2-dichloroethane degradation by Xanthobacter autotrophicus GJ 10 was investigated. Processes of dehalogenation were carried out with initial substrate concentrations of 0,12, 0,14 and 0,2 g/l 1,2-DCA in the presence and absence of constant electric field. The anode potential was maintained constant by a potentiostat of value 0,1 V vs. quinhydrone electrode. When no electric field was applied the biodegradation was impeded. It stopped before one chlorine atom in the substrate molecule was released completely. In the case of electric field application the dechlorination process is completed. The concentration of chloride ions in the medium reaches its stoichiometric values. The results shows that the stimulating effect of constant electric field is due to biophysical or biochemical influence of the field applied to bacteria but not because of electrochemical processes.