The occurrence and source identification of bisphenol compounds in wastewaters

Highlights: • BPs were measured in different WWs including inflows, influents and effluents. • Most BPs were > LOD in analysed WW. • BP removal efficiencies were in general > 96%. • BPZ was most commonly detected and BPC was quantified in WW for the first time. • Food processing and textile cleaning facilities represent major sources of BPs. This study reports the occurrence of eight bisphenols (BPs): bisphenol AF (BPAF), bisphenol AP (BPAP), bisphenol B (BPB), bisphenol C (BPC), bisphenol E (BPE), bisphenol F (BPF), bisphenol S (BPS) and bisphenol Z (BPZ) in wastewaters (WWs). Sample preparation involved pre-concentration with SPE cartridges (Oasis HLB), followed by derivatization using N-(tert-butyldimethylsilyl)-N-methyltrifluoroacetamide with 1% tert-butyldimethylchlorosilane. Chemical analysis was based on gas chromatography–mass spectrometry. A validated method with limits of detection (LODs) at ng L^{− 1} range was applied to WWs collected at five Slovene wastewater treatment plants (WWTPs) and WW inflows from industrial, commercial and residential sources entering the sewerage systems of two catchments (Domžale-Kamnik (DK) and Ljubljana (LJ)). The presence of all BPs was confirmed in three inflows in DK and two inflows in the LJ catchments. High cumulative concentrations of all BPs were determined in WW from food processing facilities (LJ: 3030 ng L^{− 1} and DK: 599 ng L^{− 1}). A high detection frequency was observed in the WW from two textile cleaning companies (6 BPs for LJ and 8 BPs for DK). The analysis of WW from WWTPs revealed that only BPF (36.7 ng L^{− 1}) and BPS (40.6 ng L^{− 1}) were > LODs in the influents, whereas other BPs were detected also in the effluents. BPZ was found in the highest concentration (403 ng L^{− 1} at WWTP-DK). WW collected at this WWTP also contained the highest amount of BPE (238 ng L^{− 1}). Although BPs removal could not be directly compared between the WWTPs, with the exception of BPAP and BPB in the case of two smaller WWTPs (6.39%–43.2%) bisphenols were in general highly removed (≥ 96.2%). Finally, levels of BPC > LOD are reported for first time (WWTP in the DK catchment: 1.01 ng L^{− 1}–11.8 ng L^{− 1}; LJ inflow from food processing plant up to 2560 ng L^{− 1}).