TBAA reduction in reactors simulating distribution system pipes

Abstract

To investigate the potential role of abiotic reduction in the loss of disinfection by‐products in distribution systems, the degradation of tribromoacetic acid (TBAA) in pipe reactors made of new and previously in‐service iron pipe was studied. TBAA was degraded in all of the reactors, with dibromoacetic acid, bromoacetic acid, and bromide as the observed products. The observation of these dehalogenation products under oxic conditions—in which oxygen would be preferred over TBAA as a terminal electron acceptor for biological processes—indicates that abiotic reduction by iron minerals at the pipe wall is responsible for the observed debromination reactions. The iron oxides formed in the pipes comprised goethite, lepidocrocite, and magnetite. Results suggest that abiotic reduction of highly reactive disinfection by‐products at the pipe wall is potentially an important loss process in distribution systems.

Disinfection byproduct formation during drinking water treatment and distribution: A review of unintended effects of engineering agents and materials

“…To understand the fate of DBPs in DWDSs and to develop possible treatment processes for removal of DBPs from drinking water, numerous studies have focused on degradation of representative DBPs (i.e. THMs, HAAs, HALs, HKs, HANs, HNMs, HAMs and NAs) in the presence of zerovalent metals (Gui et al, 2000;Hozalski et al, 2001;Zhang et al, 2004;Pearson et al, 2005;Lee et al, 2007;Arnold et al, 2010;Wang and Zhu, 2010;Han et al, 2013;Tang et al, 2015;Chu et al, 2016c;Han et al, 2017). Table 3 presents the experimental conditions and results for the reactions of DBPs with different elemental metals.…”