Sorption of 17 a -ethinylestradiol to aerobic and anaerobic sludges

Sorption tests were performed to measure the sorption capacities of aerobic and pH value were also investigated. The sorption equilibrium was established in 30 min. The EE2 concentrations in the aqueous phase and the corresponding EE2 quantities on the sludge were well correlated by both Freundlich and linear sorption isotherm models. Freundlich parameters (KF) and distribution coefficients (Kd) decreased with the increasing temperature.Distribution coefficients (Kd) of aerobic inactivated sludge were 743.8, 601.9 and 494.1 l/kg at 10oC, 20oC and 30oC, respectively; Kd of anaerobic inactivated sludge were 1205, 957.0 and 792.8 l/kg at 10oC, 20oC and 30oC, respectively. The KF and Kd of aerobic inactivated sludge were lower than those of anaerobic inactivated sludge. Sorption thermodynamics indicated that the sorption process was exothermic and spontaneous. No significant pH effect was observed in the pH range of 6-9 at 20oC; when pH>9, the sorptive capacities decreased with increasing pH value. Comparatively, sorption isotherms of the aerobic and anaerobic activated sludge were investigated at 20oC. EE2 sorption on activated sludge was also well correlated by both Freundlich and linear sorption isothermal model. Distribution coefficient (Kd) of aerobic and anaerobic activated sludge were 375.2 and 573.6 l/kg, respectively.