Occurrence and characteristics of perfluoroalkyl substances (PFASs) in electroplating industrial wastewater

摘要

The potential negative effects of perfluoroalkyl substances (PFASs) discharged into aquatic environments are drawing increasing attention. However, little research has been undertaken on PFASs in wastewater from electroplating industrial parks. In this study, the concentration profiles and geographical distribution of 11 PFASs were analyzed in water samples collected from different production workshops and an artificial landscaped lake. The total concentrations of PFASs (Sigma(11) PFASs) at various points in the production drainage system range from 229.5 to 5410.6 ng/L, and are mainly contributed by nickel plating, pickling, and the cyanide bright silver plating procedure, which correspond to cyanide-containing and acid-alkali wastewater conditioning tanks. Wastewater treatment by oxidation and precipitation removed 52.6% and 20% of PFASs, respectively. E il PFASs in effluents is about 538 ng/L, which consists of perfluorooctanoic acid (PFOA, 430.5 ng/L), followed by perfluorooctane sulfonate (PFOS, 35.27 ng/L), perfluorohexane sulfonate (PFHxS, 28.05 ng/L), and perfluorohexanoic acid (PFHxA, 18.3 ng/L). Principal component analysis suggests that the Sigma(11) PFASs in electroplating wastewater is very high and short-chain (C4-C8) PFASs have high detection and contribution rates. As a result, much attention should be paid to the increase in short-chain substitution effects and pollution around the factory area.