Department of Environmental Health Engineering, Abadan University of Medical Sciences, Abadan, Iran.
Department of Chemical Engineering, Abadan Faculty of Petroleum Engineering, Petroleum University of Technology, Abadan, 63187-14331, Iran.
Chemosphere. 2021 Dec;285:131455. doi: 10.1016/j.chemosphere.2021.131455. Epub 2021 Jul 7.
The degradation of acetaminophen (ACM) was comparatively studied by UV/chlorine and UV/HO systems. An apparent reduction in the removal rate was observed above the optimum pH levels of 7.0 and 3.0 in UV/chlorine and UV/HO processes, respectively. The relative contribution of each oxidizing agent in ACM removal using the two advanced oxidation processes (AOPs) was evaluated. Even though hydroxyl radicals, with the contribution percentage of 90.1%, were determined as the primary oxidizing species in ACM removal using the UV/HO process, reactive chlorine species (RCS), with 43.8% of contribution percentage, were also found to play a pivotal role in ACM removal using the UV/chlorine process. For instance, dichlorine radical (Cl) showed an acceptable contribution percentage of 32.2% in the degradation of ACM by the UV/chlorine process. The rate of ACM degradation significantly rose to 99.9% and 75.6%, as higher amounts of oxidants were used in the UV/chlorine and UV/HO processes, respectively, within 25 min. The introduction of HCO ions and humic acid remarkably decreased the rate of ACM degradation in both techniques used in this study. The presence of NO and Cl ions did not considerably affect the removal rate in the UV/chlorine process. The acute toxicity analysis revealed that a more pronounced reduction in the ACM solution toxicity could be achieved by the UV/HO process compared to the UV/chlorine process, which should be ascribed to the formation of chlorinated products in the UV/chlorine treatment. Eventually, plausible oxidation pathways were proposed for each process.
比较研究了 UV/氯和 UV/HO 体系中对乙酰氨基酚（ACM）的降解。在 UV/氯和 UV/HO 过程中，分别在最佳 pH 值 7.0 和 3.0 以上观察到去除率明显降低。评估了两种高级氧化工艺（AOP）中每种氧化剂在 ACM 去除中的相对贡献。尽管在 UV/HO 过程中，羟基自由基（贡献百分比为 90.1%）被确定为 ACM 去除的主要氧化剂，但也发现活性氯物质（RCS）（贡献百分比为 43.8%）在 UV/氯过程中也发挥了关键作用。例如，在 UV/氯过程中，二氯自由基（Cl）显示出可接受的 32.2%的 ACM 降解贡献百分比。在 25 分钟内，UV/氯和 UV/HO 过程中分别使用更高剂量的氧化剂，ACM 的降解速度显著提高到 99.9%和 75.6%。HCO 离子和腐殖酸的引入显著降低了这两种技术中 ACM 降解的速度。NO 和 Cl 离子的存在对 UV/氯过程中的去除速率没有显著影响。急性毒性分析表明，与 UV/氯过程相比，UV/HO 过程可以更显著地降低 ACM 溶液的毒性，这归因于在 UV/氯处理中形成氯化产物。最终，为每个过程提出了合理的氧化途径。
