Is nitrite from nitrification the only cause of microbiologically induced chloramine decay?

Abstract

Nitrite, produced by ammonia oxidizing bacteria (AOB), was traditionally thought to be the only cause of microbiologically mediated decay of chloramine. The development and application of microbial decay factor method and bacterial community studies, for the first time have revealed many other factors such as soluble microbial products (SMPs) and bacteria other than AOB mediating the decay of chloramine.

Estimation of chloramine decay in drinking water distribution systems

“…Generally speaking, distribution system-related chlorine or chloramine decay rates may be divided into that associated with pipe-wall reactions and decay associated with bulk water chemistry (Ozdemir and Buyruk, 2018). Decay related to pipe material is considered to be higher than that attributed to water due to reactions with metallic species (Vikesland and Valentine, 2000;Bal Krishna et al, 2018), aluminosilicates in cement-lined ductile iron pipe (Westbrook and DiGiano, 2009), organics leached from polymer pipe (Kiéné et al, 1998), as well as biofilm or natural organic matter (NOM) that may be attached to the pipe wall (Wang et al, 2013;Xue et al, 2014;Huang et al, 2016;Zheng et al, 2016). Pipe wall reactions consist mainly of complex redox reactions with biomass and metals, especially iron, commonly with biomass formation and scaling both increasing with pipe age.…”

“…When considering bulk water, nitrification (Reaction 3; Bal Krishna et al, 2018;Cunliffe, 1991;Woolschlager et al, 2001) and acid-catalyzed auto-decomposition (Reaction 4) (Jafvert and Valentine, 1992;Jafvert and Valentine, 1985;Vikesland et al, 1996;Woolschlager et al, 2001) also serve as primary contributors to decay.…”