Occurrence and removal of amino acids during drinking water treatment

Amino acids (AAs) are known precursors to regulated and unregulated disinfection by-products (DBPs). Nitrogenous DBPs are of concern in the drinking water industry because they can be more geno- and cytotoxic than many of the currently regulated carbon-based DBPs. The authors measured occurrences and removals of AAs in raw water and filter effluents from 16 full-scale drinking water treatment plants that treat water impaired by upstream wastewater discharge or algal growth. The AAs measured in this study accounted for only a small portion of the dissolved organic nitrogen (DON) pool and were removed, to a high degree, during drinking water treatment. This work illustrates that although amino acids can account for a more significant portion of the DON pool in natural lakes and streams, the influence of wastewater discharge and algal activity produce a pool of organic nitrogen not likely to account for all of the nitrogenous DBPs. This unidentified DON warrants identification and further study.-SB.