Occurrence and fate of bisphenol A transformation products, bisphenol A monomethyl ether and bisphenol A dimethyl ether, in wastewater treatment plants and surface water.

Due to the wide use, bisphenol A (BPA) has been detected frequently in the aquatic environment. However, the information on the distribution of BPA transformation products is limited. In this study, we investigated two BPA transformation products, namely bisphenol A monomethyl ether (BPA-MME) and bisphenol A dimethyl ether (BPA-DME). This study revealed that both transformation products were widely detected in the wastewater treatment plants (WWTPs) as well as in surface water of Jiulong River and its estuary with higher detected concentrations and detection frequencies for BPA-DME. Temporal variations were observed in a WWTP based on a five-year sampling campaign. Mass load of BPA and its transformation products was evaluated and results indicated the generation of BPA-MME and BPA-DME during the wastewater treatment processes, which contributed for 1.95% BPA removal. BPA and its transformation products were also widely detected in the surface water of Jiulong River and its estuary. Results indicated their additional generation in the surface water, since BPA-MME and BPA-DME in the surface river water were with similar level or even higher than effluent in WWTPs.