Korea Institute of Civil Engineering and Building Technology, 283 Goyangdae-Ro, Ilsanseo-Gu, Goyang-Si, Gyeonggi-Do, 10223, South Korea.
School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), 123 Cheomdangwagi-ro Buk-gu, Gwangju, 61005, South Korea.
Chemosphere. 2023 Oct;338:139450. doi: 10.1016/j.chemosphere.2023.139450. Epub 2023 Jul 12.
The composition of the wastewater matrix influences the oxidation potential of ozonation, a technique widely recognized efficient removal of micropollutants. Here, we developed a chemical kinetic model to determine the ozone dose required to minimize bromate production in wastewater containing bromine ions while achieving target removal rates. In wastewater ozonation, ozone decomposition comprises instantaneous ozone consumption and subsequent decomposition at first-order reaction rates. Under the injection condition of 1.5 g O/g dissolved organic carbon (DOC), the instantaneous ozone demand was 62.7% of the injection concentration, and it increased proportionally with increasing injected ozone concentration. Ozone and hydroxyl radical exposures were proportional to the initial ozone dose, while hydroxyl radical exposure was proportional to ozone exposure, and the deviation was relatively high at 1.0-1.5 g O/g DOC. The calculated hydroxyl radical exposure was 3.0 × 10 to 5.3 × 10 M s. Ozone and hydroxyl radicals are highly correlated with the ratio of ozone dose to organic matter concentration. Therefore, a trace substance removal rate evaluation model combined with the R model and a bromate generation model were also considered. For ibuprofen, the ozone dose for achieving the target removal rate of 80% while maintaining the bromate concentration below 50 μg L was suitable in the operating range of 0.86 g O/g DOC or more. The proposed method provides a practical operation strategy to calculate the appropriate ozone dose condition from the target compound removal rate prediction and bromate generation models considering the ratio of ozone dose to organic matter concentration in the incoming wastewater.
废水基质的组成会影响臭氧氧化的氧化电位，臭氧氧化是一种广泛认可的有效去除微量污染物的技术。在这里，我们开发了一种化学动力学模型，以确定在含有溴离子的废水中最小化溴酸盐生成所需的臭氧剂量，同时达到目标去除率。在废水臭氧氧化中，臭氧分解包括瞬时臭氧消耗和随后的一级反应速率分解。在 1.5 g O/g 溶解有机碳 (DOC) 的注入条件下，瞬时臭氧需求为注入浓度的 62.7%，并随注入臭氧浓度的增加呈比例增加。臭氧和羟基自由基暴露与初始臭氧剂量成正比，而羟基自由基暴露与臭氧暴露成正比，在 1.0-1.5 g O/g DOC 时偏差相对较高。计算得到的羟基自由基暴露值为 3.0×10 到 5.3×10 M s。臭氧和羟基自由基与臭氧剂量与有机物浓度之比高度相关。因此，还考虑了结合 R 模型和溴酸盐生成模型的痕量物质去除率评估模型。对于布洛芬，在 0.86 g O/g DOC 或更高的操作范围内，当保持溴酸盐浓度低于 50 μg/L 时，达到 80%的目标去除率所需的臭氧剂量是合适的。该方法提供了一种实用的操作策略，可根据目标化合物去除率预测和溴酸盐生成模型，考虑到来水有机物浓度与臭氧剂量的比值，计算出合适的臭氧剂量条件。
