[Effects of Goethite, Magnetite and Gypsum on the Anaerobic Degradation of 2,4-Dichlorophenol].

2,4-dichlorophenol(2,4-DCP), a highly toxic and refractory organic compound, was commonly used in pesticide production and thus widely distributed in water and soil. Goethite, magnetite and gypsum were added into the anaerobic system which simulated the natural anaerobic process to evaluate their effects on the anaerobic degradation of 2,4-DCP. It indicated that goethite, magnetite and gypsum had no appreciable adsorption ability toward 2,4-DCP under anaerobic condition. Mass balance analysis showed that only the transformation of 2,4-DCP to 4-chlorophenol(4-CP) occurred in all experimental groups. The addition of sodium acetate doubled the reductive dechlorination rate of 2,4-DCP in comparison with the groups without exogenous carbon source. The reductive dechlorination rate of 2,4-DCP was enhanced by the addition of goethite and magnetite, which was caused by the improved metabolic activity of dechlorination bacteria that played an important role in the anaerobic degradation of 2,4-DCP. Gypsum greatly inhibited or even stopped the degradation process of 2,4-DCP through restraining the growth and activity of dechlorination bacteria. This study will shed light on the migration and degradation of refractory chlorinated organic contaminants in anaerobic sedimentary environment, and the treatment of such matters in environmental technology.