Bioaccumulation and toxicity of per-and polyfluoroalkyl substances and metal in plants have been confirmed, however their contamination in soil and plants still requires extensive investigation. In this study the combined effects of chlorinated polyfluoroalkyl ether potassium sulfonate (F53B) and chromium (Cr) on water spinach ( Ipomoea aquatica Forsk ) were investigated. Compared with each single stress, the combination of F53B and Cr (VI) reduced the biomass and height and increasingly accumulated in the roots and destroyed the cell structure. Besides, the co-contamination led to the immobilization of F53B and Cr (VI) in soil, which affected their migration in soil and transfer to plants. The antioxidant response and photosynthesis of the plant weakened under the single Cr (VI) and enhanced under the single F53B treatment; however the contamination of F53B and Cr (VI) could also reduce this effect, as confirmed by the gene expression of MTa, psbA and psbcL genes. This study provides an evidence of the environmental risks resulting from the coexistence of F53B and Cr (VI).
Yun Deng,Jiankun Huang,Xingwen Lu,Da Chen,Fei Wang
Due to the limited documentation on thermal treatment of per - and polyfluoroalkyl substances (PFAS), this study investigated the thermal degradation behavior, mechanisms, mineralization, and gaseous product toxicity of five environmentally ubiquitous PFAS, including perfluorooctanesulfonic acid (PFOS), perfluorooctane sulfonamide (PFOSA), 6:2 chlorinated polyfluoroalkyl ether sulfonate (F 53B), perfluorooctanoic acid (PFOA), and 1H,1H,2H,2H-perfluoro-1-decanol (8:2 FTOH). Results showed that thermal stability of PFAS is dictated by their functional groups, presenting a stability hierarchy of sulfonic acid (PFOS, F 53B) > sulfonamide (PFOSA) > carboxylic acid (PFOA) > hydroxyl (8:2 FTOH). Thermal decomposition of these PFAS was initiated with cleavage of bonds connecting the functional group to the perfluorinated chain followed by stepwise chain-shortening reactions, yielding various perfluoroalkanes, perfluoroalkenes, and hydrofluoroalkanes. Calcium hydroxide remarkably enhanced fluorine mineralization into calcium fluoride and suppressed the formation of organofluorinated compounds during PFAS thermal treatment. Toxicity predictions indicated reduced acute toxicity for thermal degradation products compared to parent PFAS, but they still pose potential risks to human health. This implies that optimizing thermal treatment conditions is essential, focusing not only on mineralization efficiency but also on suppressing the formation of harmful by-products. These findings provide a systematic understanding of PFAS thermal decomposition and identify potentially hazardous gaseous by-products.
危险品化学品经营许可证（带存储）