Formation of bromate during ferrate(VI) oxidation of bromide in water

Journal Article

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Chemosphere

Jul

155

528

533

England

1879-1298; 0045-6535

PMID: 27153235

eng

Journal Article; IM

10.1016/j.chemosphere.2016.04.093 [doi]

Unknown(0)

27153235

Ferrate (VI) is traditionally recognized as a safe oxidant without production of disinfection byproducts (DBPs). However, here we detected probable carcinogenic bromate (BrO3(-)) during ferrate(VI) oxidation of bromide (Br(-))-containing water, and evaluated the effects of pH, ferrate(VI) dose, initial Br(-) concentration, and co-existing anions on the BrO3(-) formation. BrO3(-) was produced at a moderately-weakly acidic pH condition and in the absence of phosphate that was commonly applied as a buffer and stabilizing agent in previous ferrate(VI) studies. At pH 5.0, the produced BrO3(-) was increased from 12.5 to 273.8 mug/L with the increasing initial Br(-) concentration from 200 to 1000 mug/L at 10 mg/L Fe(VI), corresponding to an increase in the molar conversion ([BrO3(-)]/initial [Br(-)]) from 2.3% to 10.3%, in a bicarbonate-buffered solution. As pH increased to 7.0, the BrO3(-) concentration gradually dropped. The BrO3(-) production appeared to be associated with the oxidation by high valence iron species (i.e. Fe(VI), Fe(V) and Fe(IV)). Two key intermediate products (i.e. hypobromous acid/hypobromite (HOBr/OBr(-)) and hydrogen peroxide (H2O2)) relevant to the bromate formation were identified. The production of HOBr, a requisite intermediate for the ensuing bromate formation, was indirectly validated through identification of bromine-containing trihalomethanes and haloacetic acids during ferrate oxidation in a natural water, though these bromo-organic DBPs produced were insignificant. Furthermore, the inhibition effects of various anions on the formation of BrO3(-) followed chloride

Elsevier Ltd

Huang,X., Deng,Y., Liu,S., Song,Y., Li,N., Zhou,J.

School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China; Department of Earth and Environmental Studies, Montclair State University, 1 Normal Ave., New Jersey, 07043, United States.; Department of Earth and Environmen

20160503

http://vp9py7xf3h.search.serialssolutions.com/?charset=utf-8&pmid=27153235

2016