Polyfluoroalkyl\nAmine Contributed to Nitrogen-Containing\nDisinfection Byproduct Formation in Corroded Iron Drinking Water Pipes

Chlorination may cause secondary\nperfluorooctanoic acid\n(PFOA)\nformation in drinking water containing polyfluoroalkyl amine, but\nthe possibility of nitrogen-containing disinfection byproduct (N-DBP)\nformation during this process has not been recognized. Here, we found\nthat polyfluoroalkyl amine could serve as a precursor for N-DBPs in\ncorroded iron drinking water pipes in addition to the secondary generation\nof PFOA. By using nontarget analysis, 41 kinds of N-DBPs were identified\nin the water containing both ferrous and ferric corrosion products\nFe(II)/FeOOH under an initial perfluorooctyl amine (PFOM) concentration\nof 100 ng/L (PF&Fe), which was significantly higher than the control\nsamples. Most of the newly generated N-DBPs showed to have aromatic\nstructures. The increased dissolved organic nitrogen and unchanged\nF<sup>–</sup> concentrations inferred that the amine group\nin PFOM is chemically reactive while the C<sub>7</sub>F<sub>15</sub>–perfluoroalkyl chain is relatively stable. The cell viability\nin the PF&Fe sample significantly decreased from 71.56% (before\nchlorination) to 24.24% after chlorination (<i>p</i> <\n0.01), which indicated that the transformation from polyfluoroalkyl\namine to PFOA and the formation of N-DBPs increased the water quality\nrisks under chlorination in corroded iron drinking water pipes.