Fate and mass balances of triclosan (TCS), tetrabromobisphenol A (TBBPA) and tribromobisphenol A (tri-BBPA) during the municipal wastewater treatment process

Municipal wastewater treatment plants (MWTPs) are impacted by down-the-drain influents of anthropogenic chemicals. These chemicals are in consumer products and include the flame retardant tetrabromobisphenol A (TBBPA) and antimicrobial triclosan (TCS). Characterization of the distribution of TBBPA, TCS and the TBBPA product tribromobisphenol A (tri-BBPA) was determined at five stages along the treatment process of a typical Canadian MWTP facility. Overall, the TCS concentrations for both liquid (influents, primary effluents and final effluents (FEs)) and solid samples (primary and waste activated sludges) were similar to reported ranges in the literature. In contrast to TCS, both TBBPA and tri-BBPA concentrations were scarcely available in the literature. The TBBPA concentrations were within literature ranges for both influents and sludges, while the tri-BBPA sludge concentrations were markedly higher than a single available previous study. Mass balances for TCS, TBBPA and tri-BBPA indicated 7, 9 and 42%, respectively, of each chemical remaining in the FEs. The resultant annual mass loadings into the Detroit River were estimated to be 3.3 kg, 6.57 g, and 21.5 g for TCS, TBBPA and tri-BBPA, respectively.