Bromate formation in bromide-containing water by the cobalt-mediated activation of peroxymonosulfate (PMS) was investigated. Increasing PMS dosage and cobalt dosage increased the formation of bromate. The bromate formation is a two-step process involving free bromine as a key intermediate and bromate as the final product. Sulfate radicals generated in the Co/PMS system is known to participate in both two steps. In addition to the known oxidation of bromide to bromine by sulfate radicals, Co(III) also contributes to the bromine formation in the first step, as an increasing amount of bromine was produced with increasing Co dosage while no bromate was found in the presence of methanol (a sulfate radical scavenger). The contribution of Co(III) to the bromine formation was further confirmed by the addition of EDTA. Cobalt bounded by EDTA and stabilized as CoIIIEDTA- complex, cannot react with bromide, leading to insignificant bromine formation in the presence of methanol. On the other hand, sulfate radicals are essential for the second step where oxidation of bromine to bromate takes place, as Co(III) is unable to oxidize bromine to bromate.

Bromate formation in bromide-containing water by the cobalt-mediated activation of peroxymonosulfate: Roles of sulfate radicals and Co(III)

248th National Meeting (2014)

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