School of Architecture, Civil and Environmental Engineering (ENAC), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland; School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Republic of Korea.
School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, 61005, Republic of Korea.
Water Res. 2020 Jul 15;179:115852. doi: 10.1016/j.watres.2020.115852. Epub 2020 Apr 23.
Oxidative treatment of iodide-containing waters can lead to a formation of potentially toxic iodinated disinfection byproducts (I-DBPs). Iodide (I) is easily oxidized to HOI by various oxidation processes and its reaction with dissolved organic matter (DOM) can produce I-DBPs. Hydrogen peroxide (HO) plays a key role in minimizing the formation of I-DBPs by reduction of HOI during HO-based advanced oxidation processes or water treatment based on peracetic acid or ferrate(VI). To assess the importance of these reactions, second order rate constants for the reaction of HOI with HO were determined in the pH range of 4.0-12.0. HO showed considerable reactivity with HOI near neutral pH (k = 9.8 × 10 and 6.3 × 10 Ms at pH 7.1 and 8.0, respectively). The species-specific second order rate constants for the reactions of HO with HOI, HO with HOI, and HO with OI were determined as k = 29 ± 5.2 Ms, k = (3.1 ± 0.3) × 10 Ms, and k = (6.4 ± 1.4) × 10 Ms, respectively. The activation energy for the reaction between HOI and HO was determined to be E = 34 kJ mol. The effect of buffer types (phosphate, acetate, and borate) and their concentrations was also investigated. Phosphate and acetate buffers significantly increased the rate of the HO-HOI reaction at pH 7.3 and 4.7, respectively, whereas the effect of borate was moderate. It could be demonstrated, that the formation of iodophenols from phenol as a model for I-DBPs formation was significantly reduced by the addition of HO to HOI- and phenol-containing solutions. During water treatment with the O/HO process or peracetic acid in the presence of I, O and peracetic acid will be consumed by a catalytic oxidation of I due to the fast reduction of HOI by HO. The O deposition on the ocean surface may also be influenced by the presence of HO, which leads to a catalytic consumption of O by I.
含碘水的氧化处理会导致潜在有毒的碘代消毒副产物（I-DBPs）的形成。碘（I）很容易被各种氧化过程氧化为 HOI，其与溶解有机物（DOM）的反应会产生 I-DBPs。过氧化氢（HO）在基于 HO 的高级氧化过程或基于过乙酸或高铁酸盐（VI）的水处理中，通过还原 HOI 来最小化 I-DBPs 的形成方面起着关键作用。为了评估这些反应的重要性，在 pH 值为 4.0-12.0 的范围内确定了 HOI 与 HO 反应的二级速率常数。HO 在接近中性 pH 时对 HOI 表现出相当大的反应性（在 pH 7.1 和 8.0 时，k 值分别为 9.8×10 和 6.3×10 M s）。HO 与 HOI、HO 与 HOI 和 HO 与 OI 的反应的特定物种的二级速率常数分别确定为 k = 29±5.2 Ms、k =（3.1±0.3）×10 Ms 和 k =（6.4±1.4）×10 Ms。HOI 和 HO 之间反应的活化能确定为 E = 34 kJ mol。还研究了缓冲类型（磷酸盐、乙酸盐和硼酸盐）及其浓度的影响。磷酸盐和乙酸盐缓冲剂在 pH 7.3 和 4.7 时分别显著增加了 HO-HOI 反应的速率，而硼酸盐的影响适中。可以证明，通过向含有 HOI 和苯酚的溶液中添加 HO，可以显著减少碘代酚类物质的形成，这是碘代消毒副产物形成的模型。在含有 I 的情况下，通过 O/HO 过程或过乙酸进行水处理时，由于 HOI 的快速还原，O 和过乙酸将被消耗。HO 的存在也可能影响海洋表面的 O 沉积，导致 I 对 O 的催化消耗。
