Bromate Formation from Bromide Oxidation by the UV/Persulfate Process
Bromate Formation from Bromide Oxidation by the UV/Persulfate Process
复制标题
通过紫外线/过硫酸盐工艺氧化溴化物形成溴酸盐
DOI：
10.1021/es300658u
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发表时间：
2012-08-21
影响因子：
11.4
通讯作者：
Shang, Chii
中科院分区：
文献类型：
--
作者：
Fang, Jing-Yun;Shang, Chii
研究了溴化物在UV/过硫酸盐氧化过程中生成溴酸盐的过程，以及超纯水和含溴化物的真实水中pH、过硫酸盐用量和溴化物浓度的变化。总体上，溴酸盐的生成随过硫酸盐用量和溴化物浓度的增加而增加。溴酸盐的生成主要是由硫酸盐自由基（SO4中心点-）引发和驱动的，并涉及到作为中间产物的次溴酸/次溴酸盐（HOBr/OBr-）和最终产物溴酸盐的形成。在试验条件下，由SO4中心点-驱动的第一步速度比第二步慢。直接紫外光解HOBr/OBr-生成溴酸盐和溴酸盐光解作用不显著。当pH值从7增加到9以上时，溴酸盐的生成减少了90%以上。与超纯水相比，真实水样中溴酸盐的形成较少，这主要是由于存在与溴原子、HOBr/OBr-和SO4中心点-反应的天然有机物。然而，溴酸盐的形成程度和微污染物的降解是耦合过程，除非中间溴种被实际水中的NOM消耗。
Bromate formation from bromide oxidation by the UV/persulfate process was investigated, along with changes in pH, persulfate dosages, and bromide concentrations in ultrapure water and in bromide-spiked real water. In general, the bromate formation increased with increasing persulfate dosage and bromide concentration. The bromate formation was initiated and primarily driven by sulfate radicals (SO4 center dot-) and involved the formation of hypobromous acid/hypobromite (HOBr/OBr-) as an intermediate and bromate as the final product. Under the test conditions, the rate of the first step driven by SO4 center dot- is slower than that of the second step. Direct UV photolysis of HOBr/OBr- to form bromate and the photolysis of bromate are insignificant. The bromate formation was similar for pH 4-7 but decreased over 90% with increasing pH from 7 to above 9. Less bromate was formed in the real water sample than in ultrapure water, which was primarily attributable to the presence of natural organic matter that reacts with bromine atoms, HOBr/OBr- and SO4 center dot-. The extent of bromate formation and degradation of micropollutants are nevertheless coupled processes unless intermediate bromine species are consumed by NOM in real water.