Polydiallyldimethyl ammonium chloride (polyDADMAC) is the most commonly used polymer at drinking water treatment plants and is known to react during the disinfection process to form nitrosamines, like n-nitrosodimethylamine (NDMA). NDMA is a potential human carcinogen in water at concentrations as low as 0.7 ng/L leading to a 10-6 lifetime cancer risk. This study used 13C nuclear magnetic resonance (NMR) to analyze the polymer solution’s composition and structural changes during disinfection by chloramination. It is proposed that NDMA forms during chloramination by ring-opening of the polyDADMAC, which can be tracked via 13C NMR. The information from this study can be used to mitigate the formation of NDMA during disinfection at drinking water treatment plants.

<sup>13</sup>C nuclear magnetic resonance enables understanding of ring-opening mechanism of polydiallyldimethyl ammonium chloride during chloramination

ACS Spring Meeting 2021

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13C nuclear magnetic resonance enables understanding of ring-opening mechanism of polydiallyldimethyl ammonium chloride during chloramination

¹³C nuclear magnetic resonance enables understanding of ring-opening mechanism of polydiallyldimethyl ammonium chloride during chloramination