AWWA WQTC65941

Two pathways have been suggested to account for nitrile [HAN, CNCl] formation during chlorine or chloramine disinfection. The first pathway, the "decarboxylation pathway", has been studied by numerous researchers. A second pathway, the "aldehyde pathway", is based on a reaction between monochloramine and aldehydes to form the corresponding nitrile. As part of a study on nitrogenous (N) disinfection byproducts (DBPs), two halogenated disinfection byproduct formation potential (DBPFP) tests were conducted in raw and treated waters: one in the presence of chlorine; and, the other in the presence of chloramines. The latter formation potential (FP) test was also used for the evaluation of NDMA precursors. Moreover, a third FP test was developed, with pre-chlorination and post-chloramination, in order to measure cyanogen halide (CNX) precursors. Objectives of this study included identification of N-DBP precursors in source waters, the formation and control of N-DBPs, and their mechanism of formation. Includes 29 references, figures.