PFAS Promotes Disinfection Byproduct Formation Through Triggering Particle-bound Organic Matter Release in Drinking Water Pipes
By Xinyi Qin, Yuan Zhuang, and Baoyou Shi
Water Research
February 21, 2024
DOI: 10.1016/j.watres.2024.121339
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 perfluorinated and polyfluorinated substances (PFASs) could dramatically promote the formation of disinfection byproducts (DBPs) by triggering the release of particle-bound organic matter. Carboxylic acid PFASs have a greater ability to increase chloroacetic acid than sulfonic acid 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. Our 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.
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