Formation of cyanogen chloride by the reaction of amino acids with hypochlorous acid in the presence of ammonium ion

Precursors of nitrogenous disinfection by-products in drinking water––A critical review and analysis

“…Where available, the yields of N-DBPs from specific algae species cultured under laboratory conditions were also collated ( [51][52][53] Table 4). Data about N-DBP formation as measured by disinfecting model compounds using FP protocols was also collected and converted into molar conversion yields ( [12,14,[27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44], Table 2). These yields were then used to estimate the levels of N-DBPs that are formed on the basis of precursor concentrations in environmental samples (from WTWs, WWTWs or surface waters) ( [5,25,30,31,37,41,46,[54][55][56][57][58][59][60][61][62], Table 5).…”

“…Serine and threonine were reported to produce CNCl at yields of 11.2% and 13.7%, respectively, following chloramination [33] ( Table 2). The mechanism postulated by the authors is equivalent to amino acid chlorination (Figs.…”

“…In both, the nitrogen in CNCl can be provided by either the disinfectant (monochloramine) or the precursor. By reacting leucine with N 15 -labelled chloramines it was concluded that the precursor provided the nitrogen [33], which indicates the nitrile route was dominant under the study conditions ([N/Cl] 2:3, pH 6 Table 2). However, a formation potential test (3 h pre-chlorination, 21 h chloramination) using raw water determined that around half of CNCl formation was attributable to N 15 [31].…”

“…These tests are designed to maximise DBP formation and so use an excess of disinfectant, and they typically consider a range of contact times (1 h-10 days, [12,14,[27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44], Table 3) and, to a lesser degree, temperatures (normally 20-25 • C, [12,14,[27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44], Table 3). Hence using conversion yields from laboratory FP tests will often overestimate DBPs relative to the same precursors exposed to lower disinfectant concentrations, disinfectant contact times, and temperatures, as in actual WTWs.…”

Activated Carbon Sphere with Antibacterial Characteristics

“…1,2) Organic compounds such as quarternary ammonium salts and chlorine disinfectant have been used as conventional antibacterial agents for the elimination of microbial contamination, 3) but noxious materials in the human body may be included in the organic agent. 4) Therefore, novel pasteurization and antibacterial treatments have been required.…”