Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of the Chinese Academy of Sciences, Beijing, 100019, China.
Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; Department of Environmental Science and Engineering, School of Light Industry, Beijing Technology and Business University, Beijing, 100048, China.
Chemosphere. 2020 Aug;252:126596. doi: 10.1016/j.chemosphere.2020.126596. Epub 2020 Mar 25.
Minimizing bromate formation by adding HO is one major option for bromide-containing source water when applying ozone in drinking water. However, difference in background water quality can have a significant influence on bromate depression. In this study, three bromide-bearing source waters (YZ, HR and HP) were selected to investigate bromate depression during the HO-ozonation process. The results showed that there was strong correlation between bromate formation and molecular ozone consumption during ozonation process for the three waters. Compared to YZ and HR, ozone was consumed quickly within about 10 min for HP water, inducing lower bromate formation during ozonation process. In the initial step of bromide oxidation, molecular ozone oxidation was responsible for more than 80% of oxidation, much higher than that by hydroxyl radicals. Specifically, 94% of the oxidation of bromide occurred with ozone for YZ water, which might be attributed to the low concentration of organic matter in the water. The residual molecular ozone would be a restrictive factor and affect the bromate formation significantly. For YZ and HP water, as HO/O (g/g) increased to 0.5, the ozone decomposition rate increased 61 times and 7.2 times respectively, which resulted in difference in bromate depression performance when applying HO. Humic acid and tyrosine in water were confirmed to have effects on bromate formation and depression after HO addition. This study could elucidate the different bromate depression effects occurring in different source waters when adding HO, which will provide an informative guide for bromate control in drinking water treatment.
通过添加 HO 来最小化溴酸盐的形成是在饮用水中应用臭氧时处理含溴源水的主要选择之一。然而，背景水质的差异会对溴酸盐的抑制产生重大影响。在这项研究中，选择了三种含溴源水（YZ、HR 和 HP）来研究 HO-臭氧化过程中的溴酸盐抑制。结果表明，三种水的臭氧化过程中，溴酸盐的形成与分子臭氧的消耗之间存在很强的相关性。与 YZ 和 HR 相比，HP 水的臭氧在大约 10 分钟内迅速消耗，导致臭氧化过程中溴酸盐的形成较低。在溴化物氧化的初始阶段，分子臭氧氧化负责超过 80%的氧化，远高于羟基自由基的氧化。具体来说，YZ 水中溴化物的氧化有 94%是通过臭氧进行的，这可能归因于水中有机物浓度较低。残留的分子臭氧将是一个限制因素，并会显著影响溴酸盐的形成。对于 YZ 和 HP 水，当 HO/O（g/g）增加到 0.5 时，臭氧分解速率分别增加了 61 倍和 7.2 倍，这导致了添加 HO 时溴酸盐抑制性能的差异。水中的腐殖酸和酪氨酸被证实对添加 HO 后的溴酸盐形成和抑制有影响。本研究可以阐明在添加 HO 时不同源水中发生的不同溴酸盐抑制效果，为饮用水处理中的溴酸盐控制提供有价值的指导。
