Per- and polyfluoroalkyl compounds (PFASs) are a class of chemical substances that are the focus of pollutant control work. They have characteristics such as persistence, bioaccumulation, and water-phase migration. Among them, chlorinated polyfluorinated ether sulfonate (Cl-PFESA, also known as F-53B) is a compound widely used in the chrome plating industry.
Other Fluorinated Organic Building Blocks
The discharge of industrial sewage and sludge is the main way for F-53B to enter the environment. Ascertaining the regional emission source and emission inventory of the F-53B in the environment is an important basic work for source reduction.
This work selected electroplating wastewater and textile printing and dyeing industrial sewage, and investigated the process flows of two industrial sewage treatment facilities. Sludge and sewage samples from different water treatment processes were collected based on hydraulic retention time.
Researchers found that 6:2 F-53B and 8:2 F-53B were found to be relatively high in electroplating wastewater, accounting for 18% and 0.7% of the total PFAS, respectively. In addition, trace amounts of 6:2 F-53B and 8:2 F-53B were detected in printing and dyeing wastewater. In addition, different wastewater treatment units can affect the concentration distribution of 6:2 F-53B and 8:2 F-53B.
To better trace the migration behavior of different F-53Bs, the researchers calculated the 6:2 F-53B and 8:2 F-53B ratios and found that the signal "is similar to the isotope ratio."
Fractionation occurred to varying degrees in different wastewater treatment units and could indicate the key processes responsible for the change in the 6:2 and 8:2 F-53B ratios. It is worth noting that the 6:2/8:2 F-53B ratio fractionation in the flocculation tank and sedimentation tank is significant, which is related to pH changes and solid phase adsorption introduced during the feeding process. In addition, there was a significant difference in the 6:2/8:2 F-53B ratio in the sludge compared with the sewage sample. This result provides important information for understanding the fate and migration and transformation behavior of F-53B in industrial wastewater treatment facilities.
