New insights into the occurrence and fate of per-and polyfluoralkyl substances in textile dyeing wastewater along different treatment processes to receiving river

Abstract

Per-and polyfluoroalkyl substances (PFAS) are widely used in the textile dyeing industry resulting in textile dyeing wastewater being discharged as a significant source of PFAS in aquatic environments.However, very limited information is available on the occurrence and fate of PFAS among different textile dyeing wastewater treatment processes. This study investigated thirteen targeted PFAS across 15 textile dyeing enterprises (abbreviate as A1-A15), 4 wastewater treatment plants (abbreviated as WWTPs 1-4), and 5 receiving surface waters. Specifically, WWTP-1 and WWTP-2 were equipped with Anaerobic-Anoxic-Oxic (A 2 /O), while that of WWTP-3 and WWTP-4 were Anoxic-Oxic (A/O).Four WWTPs were respectively treated raw textile dyeing wastewaters from A1-6, A7-A11, A12-A13, and A14-A15 for standard emission. Results indicated that total concentration of 13 PFAS (Σ 13 PFAS) ranged from 23.80 to 1867.33 ng/L in raw textile dyeing wastewaters, with short-chain perfluorocarboxylic acids (PFCA) accounting for 60%. The comparison of two different treatment processes demonstrated that A 2 /O process was more effective for the removal of long-chain PFCA, which was contributed to the transformation of long-chain PFAS by anaerobic environment.Moreover, the Σ 13 PFAS in five surface waters were 235.46 to 2787.03 ng/L, and the correlation analysis revealed significant similarity of PFAS composition among surface waters with A3, A11, and WWTP-1 effluent (p < 0.01). Overall, this study comprehensively penetrated the PFAS occurrence and fate along textile dyeing wastewater to associated wastewater treatment and receiving river, thus providing new insights into different textile dyeing wastewater treatment on PFAS dynamics alteration.