Effect of electron acceptor on anaerobic toluene biodegradation in rice field and tidal mud flat

In oil-contaminated environments, anaerobic biodegradation of toluene depended on the concentration and distribution of terminal electron acceptor as well as the physicochemical properties such as DO concentration, redox potential and pH. This study showed the anaerobic biodegradation of toluene in two different soils by using nitrate reduction, ferric iron reduction, sulfate reduction and methanogensis. Toluene degradation rates in the soil samples taken from rice filed and tidal mud flat by nitrate reduction were higher than those by other processes. The soil samples from the two fields were enriched for 130 days by providing toluene as a sole carbon source and nitrate of sulfate as a terminal electron acceptor. The toluene degradation rates in the enriched denitrifying consortia obtained from the rice field and tidal mud flat soil were 310.7 and 200.6 μmol L^-1 d^-1, respectively. The toluene degradation rates in the enriched sulfate-reducing consortia from the fields ranged from 149.1 to 86.1 μmol L^-1 d^-1.