Bisphenol A: Quantification in Complex Matrices and Removal by Anaerobic Sludges

Abstract

The endocrine disruptor bisphenol A (BPA) is one of the most commonly found micropollutants in the environment. However, the biodegradation of BPA under anaerobic (methanogenic) conditions is still an understudied process in wastewater treatment systems. The current study thus addresses the need for a simple and user-friendly analytical method for the rapid and accurate quantification of BPA in complex matrices such as digested and co-digester sludges. We established a microwave-assisted extraction method, followed by derivatization and gas chromatography–mass spectrometry to quantify BPA by comparing it with a deuterated internal standard. The BPA removal capabilities of three digester sludges and three co-digester sludges were examined under mesophilic methanogenic conditions in biogas plants. The endogenous BPA concentration (dry weight) ranged from 1596 to 10,973 µg kg−1 in digested sewage sludges, and from below the limit of quantification to 9069 µg kg−1 in co-digester sludges. When BPA was added to the sludges, the removal capabilities ranged from not significant to 50% after 21 days of incubation. Biogas production was unaffected by the addition of BPA (228 µg kg−1) to the aqueous sludge. The study demonstrated that BPA could be removed under anaerobic conditions in accustomed inoculates. The findings have far-reaching implications for understanding BPA persistence and detoxification under anaerobic conditions.

Effect of Emerging Micropollutants on the Anaerobic Digestion of Sewage Sludge

“…Because sewage sludge valorization by biogas production is widely applied in the management of WWTPs, some studies have focused on the effect of BPA on biogas production. Digester sewage sludges and co-digester sewage sludges (with silage, farm manure, livestock and farming waste, food waste, and the organic fraction of municipal solid waste) have been investigated under mesophilic methanogenic conditions [16]. These sludges contained endogenous BPA at levels of up to 10,973 µg/kg d.w. (digested sludges) and up to 9069 µg/kg d.w. (co-digested sludges).…”

“…Even though emerging pollutants are frequently detected in WAS and anaerobic treatment predominates in WWTPs, the interference of emerging pollutants with anaerobic digestion is overlooked. The fact that the influence of emerging micropollutants on the anaerobic digestion of sewage sludge in WWTPs has not been systematically reported may result from the fact that simple and rapid analytical methods for the accurate quantification of these pollutants in complex matrices such as sewage sludges were not yet developed [16]. In addition, the lack of systematic reports on the effect of emerging pollutants on anaerobic digestion results from the huge diversity of these compounds, whose structure and physicochemical properties strongly affect their behavior under environmental conditions [17].…”