Sorption and Biodegradation of 17beta-Estradiol by Acclimated Activated Sludge under Anaerobic Conditions

The sorption and biodegradation of 17beta-estradiol (E2) was investigated by spiking E2 into acclimated activated sludge under anaerobic conditions in laboratory-scale. The effect of temperature on the sorption and biodegradation was also studied. Results showed that, E2 was removed 99% after 2 h for the tested concentrations (5-15 mugldrL^-1). E2 sorption followed both the Freundlich and linear sorption models. The distribution coefficient (K_d) was 543.7 Lldrkg^-1 at 20degC. E2 degradation was well described by first-order reaction kinetics and the rate constant was 2.765 h^-1 at 20degC. Temperature has significant effect on both the sorption and biodegradation of E2 by activated sludge. Distribution coefficient decreased but reaction rate constant increased with the increasing temperature. Partitioning played a significant role in the transfer of E2 between the aqueous phase and the sludge phase. The biodegradation behavior was inside the sludge phase.