| Abstract
| - Two natural waters were fortified with various levels ofbromide or iodide ions (0−30 μM) and chlorinated in thelaboratory to study the impact of bromide and iodide ions onthe formation and speciation of disinfection byproducts.Trihalomethanes (THMs), haloacetic acids (HAAs),total organic halogen (TOX), and its halogen-specificfractions total organic chlorine (TOCl), bromine (TOBr),and iodine (TOI), were measured in this work. The molaryields of THMs and HAAs increased as the initial bromideconcentration increased. No significant change in TOXconcentration was found for varying bromide concentrations.However, TOX concentrations decreased substantiallywith increasing initial iodide concentrations. At higher levelsof bromide, there was a decreasing level of unknownTOX and unknown TOCl but an increasing level of unknownTOBr. The extent of iodine substitution was much lowerthan that of bromine substitution when comparing identicalinitial concentrations because a substantial amount ofiodide was oxidized to iodate by chlorine. The tendencytoward iodate formation resulted in the unusual situationwhere higher chlorine doses actually caused reduced levelsof iodinated organic byproducts. Quantitative assessmentof the results of this study showed a good agreementwith kinetic data in the literature.
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