The electroplating industry is an important source of per- and polyfluoroalkyl substances (PFAS) contamination, but there is a lack of comprehensive studies on the occurrence, transport, and removal of PFAS in electroplating parks. In this study, we investigated typical electroplating parks in China and conducted the first full-scale removal of PFAS from chromium-plating wastewater using pore-enlarged granular activated carbon (GAC) and hydrophobic anion exchange resin (AER). The results showed that 6:2 fluorotelomer sulfonate (6:2 FTS) gradually replaced perfluorooctanesulfonate (PFOS) in China's electroplating industry. The conventional reduction-sedimentation process hardly removed 6:2 FTS from chromium-plating wastewater, while the special air flotation process resulted in over 60% of PFOS entering the chromium sludge cake. Based on the full-scale evaluation, GAC and AER adsorption were feasible technologies for removing PFAS from chromium-plating wastewater, among which AER had higher adsorption capacity and removal efficiency for PFAS but poorer selectivity for 6:2 FTS than for PFOS. It is estimated that GAC and AER adsorption have the potential to reduce the discharge of PFAS by 5030-8000 kg/year in China. This study reveals the current status of PFAS contamination in China's electroplating industry and provides feasible technologies for PFAS control.
Keywords: PFAS; anion exchange resin; chromium-plating wastewater; electroplating industry; granular activated carbon.