Abstract：
Loose deposit particles in drinking water distribution system commonly exist as mixtures of metal oxides, organic materials, bacteria, and extracellular secretions. In addition to their turbidity-causing effects, the hazards of such particles in drinking water are rarely recognized. In this study, we found that trace per- and polyfluoroalkyl substances (PFASs) could dramatically promote the formation of disinfection byproducts (DBPs) by triggering the release of particle-bound organic matter. Carboxylic PFASs have a greater ability to increase chloroacetic acid than sulfonic PFASs, and PFASs with longer chains have a greater ability to increase trichloromethane release than shorter-chain PFASs. Characterization by organic carbon and organic nitrogen detectors and Fourier transform ion cyclotron resonance mass spectrometry revealed that the released organic matter was mainly composed of proteins, carbohydrates, lignin, and condensed aromatic structures, which are the main precursors for the formation of DBPs, particularly highly toxic aromatic DBPs. After the release of organic matter, the particles exhibit a decrease in surface functional groups, an increase in surface roughness, and a decrease in particle size. The findings provide new insights into the risks of loose deposits and PFASs in drinking water, not only on PFASs per se but also on its effect of increasing toxic DBPs.
摘要：
饮用水分配系统中的松散沉积物颗粒通常以金属氧化物的混合物形式存在，有机材料,细菌,和细胞外分泌物.除了它们引起浑浊的影响，这种颗粒在饮用水中的危害很少被认识到。在这项研究中,我们发现痕量的全氟烷基和多氟烷基物质（PFASs）可以通过触发颗粒结合的有机物的释放来极大地促进消毒副产物（DBPs）的形成。羧酸PFAS比磺酸PFAS具有更大的增加氯乙酸的能力，具有较长链的PFAS比短链的PFAS具有更大的增加三氯甲烷释放的能力。通过有机碳和有机氮检测器和傅里叶变换离子回旋共振质谱进行表征，发现释放的有机物主要由蛋白质组成，碳水化合物,木质素,和缩合的芳香结构，它们是DBPs形成的主要前兆，特别是高毒性的芳香族DBPs。有机物释放后,颗粒表现出表面官能团的减少，表面粗糙度的增加，和颗粒尺寸的减小。这些发现为饮用水中松散沉积物和PFAS的风险提供了新的见解，不仅对PFAS本身，而且对其增加有毒DBPs的影响。
