Recently, sulfate radical (SO4�-)-based advanced oxidation processes (SR-AOPs) have attracted great scientific interest for the decontamination of waters. However, ubiquitous halide ions in water can be easily oxidized by SO4�- to halide radical species (HRS). HRS can subsequently react with natural organic matter to form halogenated organic byproducts (DBPs in particular), which is one of the primary issues of concern for the real water/wastewater application of SR-AOPs. Br- is potentially of more significant concern as the reactivity of Br- with SO4�- is about 11-fold higher than that of chloride ion.  To improve understanding of bromide effect on SR-AOPs, the formation of brominated organic compounds (TOBr) and Br-DBPs of 4 NOM isolates (5 mg L-1) by SR-AOPs in the presence of 2 mg L-1 bromide ion were investigated in comparison with bromination. A magnetically separable CuFe2O4 spinel catalyst was employed to activate the decomposition of peroxymonosufate for the generation of SO4�-. As expected, considerable formation of TOBr from SO4�- oxidation was observed, ranging from 127 � 243 �g L-1. About 6.5 � 12.2% of the initial bromide was analyzed as TOBr after 2 h. It was found that Br-DPBs only constituted 22 - 33% of TOBr, however, up to 78% of the AOBr are unknown brominated organic compounds. Speciation analysis revealed that dibromoacetic acid was the predominant Br-DBPs, accounting for up to 90% of HAAs and 54% of total identified Br-DBPs by weight, followed by bromoform which contributed to 75 � 3% of the THMs and 31 � 3% of total identified Br-DBPs, respectively. In contrast, NOM isolates upon bromination were more susceptible to the formation of Br-THMs. TBM was by far the major contributor of total identified Br-DBPs (63 - 86% on a weight basis) upon bromination. Besides, bromination tended to form highly halogenated HAAs (DBAA and to a less extent TBAA), while SR-AOPs oxidation yielded mainly DBAA with negligible TBAA.

Formation of brominated organic compounds from natural organic matter isolates by sulfate radical-based advanced oxidation processes

248th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.