This study investigated the mechanisms of mixed IO₃⁻/I⁻ system under UV irradiation in drinking water and compared the iodinated trihalomethanes (I-THMs) formation of a mixed IO₃⁻/I⁻ system to that of single I⁻ and IO₃⁻ systems during subsequent chloramination. The effects of initial I⁻/IO₃⁻ molar ratio, pH, and UV intensity on a mixed IO₃⁻/I⁻ system were studied. The introduction of I⁻ enhanced the conversion rate of IO₃⁻ to reactive iodine species (RIS). Besides, IO₃⁻ degradation rate increased with the increase of initial I⁻ concentration and UV intensity and the decrease of pH value. In a mixed IO₃⁻/I⁻ system, IO₃⁻ could undergo direct photolysis and photoreduction by hydrated electron (e_aq⁻). Moreover, the enhancement of I-THM formation in a mixed IO₃⁻/I⁻ system during subsequent chloramination was observed. The I-THM yields in a mixed IO₃⁻/I⁻ system were higher than the sum of I-THMs produced in a single IO₃⁻ and I⁻ systems at all the evaluated initial I⁻ concentrations and pH values. The difference between I-THM formation in a mixed IO₃⁻/I⁻ system and the sum of I-THMs in a single IO₃⁻ and I⁻ systems increased with the increase of initial I⁻ concentration. As the initial pH decreased from 9 to 5, the difference of I-THM yields enhanced, while the total I-THM yield of a mixed IO₃⁻/I⁻ system and single I⁻ and IO₃⁻ systems decreased slightly. Besides, IO₃⁻-I⁻-containing water with DOC concentration of 2.5-4.5 mg-C/L, which mainly contained humic-acid substances, had a higher risk in I-THMs formation than individual I⁻-containing and IO₃⁻-containing water.

本研究调查混合IO的机制₃ ^- / I ^-在饮用水系统UV辐射下，并比较了碘化三卤甲烷（I-三卤甲烷）形成的混合IO的₃ ^- / I ^-系统到单个I的^-和IO ₃ ⁻后续氯化过程中的系统。初始I的效果^- / IO ₃ ^-的摩尔比，pH值，并在混合IO UV强度₃ ^- / I ^-系统进行了研究。的我引进^-增强IO的转化率₃ ^-反应性碘（RIS）。此外，IO ₃ ^-降解速率与初始I的增加而增加^-浓度和UV强度和pH值的降低。在混合IO ₃ ^- / I ^-系统，IO ₃ ^-可以经历通过水合电子直接光解和光还原（E_水溶液^- ）。此外，I-THM形成在混合IO增强₃ ^- / I ^-观察系统随后氯胺期间。的I-THM产量在混合IO ₃ ^- / I ^-系统比I-三卤甲烷的在单个IO产生的总和更高₃ ^-和我^-系统在所有的评价初始I ^-浓度和pH值。I-THM形成之间在混合IO的差₃ ^- / I ^-系统和I-三卤甲烷的在单个IO总和₃ ^-和我^-系统增加了与初始I的增加^-浓度。作为初始pH从9减少到5，I-THM的差异产生增强的，而混合IO的总I-THM收率₃ ^- / I ^-系统和单个I ^-和IO ₃ ^-系统略有下降。此外，IO ₃ ^--I ^-含水的2.5-4.5毫克-C / L，其主要含有腐植质的酸性物质DOC浓度，不得不在I-三卤甲烷的形成比单独的I更高的风险^-含和IO ₃ ^-含水。