School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, China.
School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, China.
Water Res. 2022 Sep 1;223:118967. doi: 10.1016/j.watres.2022.118967. Epub 2022 Aug 9.
Dissolved organic matter (DOM), ubiquitous in natural waters, is known to inhibit the degradation of micropollutants in the advanced oxidation processes such as the UV/peroxydisulfate process. However, the quantitative understanding of the inhibitory pathways is missing. In this study, guanosine, aniline and catechol belonging to amines, purines and phenols were first investigated due to their resistance to UV irradiation at 254 nm and similar reactivity with SO and HO, respectively. The presence of 0.5 mg L Suwannee River NOM (SRNOM) inhibited their degradation rates by 72.9%, 54.5%, and 32.4%, respectively, despite their similar degradation rates in the absence of SRNOM. The results highlight the importance of reverse reduction of oxidation intermediates to the parent compound by antioxidant moieties in SRNOM besides the inner filtering and radical scavenging effects. The three inhibitory pathways were quantified for 34 common micropollutants. In the presence of 0.5 mg L SRNOM, inner filtering effect was found to contribute less than 2.8% of the inhibitory percentages (IP). Radical scavenging effects contribute between 10.7% and 38.9% and compounds having lower reactivity with SO (< 4.0 × 10 M s) tended to be inhibited more strongly. The IP of reverse reduction effects of SRNOM varied significantly from none up to 70.8%. It was linearly related with a micropollutant's reduction potential. Purines and amines generally exhibited more pronounced reverse reduction inhibition than phenols. The results of this study provide guidance on improving the elimination efficiency of micropollutants.
溶解有机物（DOM）普遍存在于天然水中，已知会抑制高级氧化过程（如 UV/过二硫酸盐过程）中微污染物的降解。然而，其抑制途径的定量理解尚不清楚。在这项研究中，由于它们在 254nm 的紫外线照射下具有抗性，并且与 SO 和 HO 的反应性相似，因此首先研究了鸟嘌呤、苯胺和儿茶酚等属于胺、嘌呤和酚的物质。尽管在没有 SRNOM 的情况下，它们的降解速率相似，但 0.5mg/L 苏万尼河天然有机物（SRNOM）的存在分别抑制了它们的降解速率 72.9%、54.5%和 32.4%。结果强调了抗氧化部分通过还原中间产物回到母体化合物的反向还原对 SRNOM 中除内过滤和自由基清除效应之外的重要性。对于 34 种常见的微污染物，量化了三种抑制途径。在 0.5mg/L SRNOM 的存在下，发现内过滤效应对抑制百分比（IP）的贡献小于 2.8%。自由基清除效应的贡献在 10.7%至 38.9%之间，并且与 SO 反应性较低（<4.0×10 M s）的化合物往往受到更强的抑制。SRNOM 反向还原效应的 IP 差异很大，从没有到 70.8%。它与微污染物的还原电位呈线性关系。嘌呤和胺通常比酚类表现出更明显的反向还原抑制作用。本研究的结果为提高微污染物的去除效率提供了指导。
