Behaviors and environmental risk assessment of estrogenic endocrine disruptors in anaerobic domestic wastewater treatment

Abstract

Solid phase extraction-LC/MS/MS detection method was applied to study the concentrations and sludge adsorptions of nine estrogenic endocrine disruptors (EEDs) in an upflow anaerobic sludge blanket (UASB) and an anaerobic filter (AF). Nonylphenol equivalent quantity (NEQ) was calculated to evaluate the environmental risk of the EEDs. The results show anaerobic sludge adsorption has positive correlation with lgKow and molecular length of EEDs. 17β-estradiol (E2) and daidzein reached 83.2% and 90.4% removal rates in UASB, respectively. Genistein in AF is removed more than 80%. The sludge-water partition coefficient(Kp) of nine EEDs ranged from 0.15-23.3 in UASB and 0.05-159.67 in AF. Biodegradation could be the main elimination pathway for daidzein, genistein, bisphenol A and estriol, by combining analysis of removal data and Kp values. Environmental risk of EEDs was reduced after anaerobic treatment, as effluent NEQ was below the US EPA nonylphenol criteria (28 μg·L-1, hour average concentration standard).