The effectiveness of a one‐month switch from chloramines to free chlorine for control of nitrification and the consequences of this strategy were evaluated in three distribution systems. Nitrification was observed in two of the systems, and may have been influenced by greater loss of disinfectant residual in cast‐iron pipe sections. Free chlorine inhibited nitrification episodes, though evidence of nitrification was observed several months after the return to chloramines. Ammonia‐oxidizing bacteria (AOB) were found attached to pipe‐wall specimens removed from a distribution system during and at the end of the free‐chlorination period, suggesting AOB persisted during free chlorination. Consequences of disinfectant switching include breakpoint chlorination reactions that caused periods of low disinfectant residuals and increased total trihalomethane (TTHM) concentrations. The highest TTHM concentration might not be observed until long after the return to chloramines at locations with long residence time where free chlorine remains.
No takes yet. Share an insight, caveat, or question.
Carrico et al. (2008) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: