Fedorov Kirill, Wang Chongqing, Shah Noor S, Boczkaj Grzegorz
Gdańsk University of Technology, Faculty of Civil and Environmental Engineering, Department of Sanitary Engineering, G. Narutowicza 11/12 Str, 80-233, Gdańsk, Poland.
School of Chemical Engineering, Zhengzhou University, Zhengzhou, 450001, China.
J Environ Manage. 2025 Sep;391:126506. doi: 10.1016/j.jenvman.2025.126506. Epub 2025 Jul 10.
Advanced reduction processes (ARPs) of SO/UV were combined with hydrodynamic cavitation (HC) for the first time to attempt a reductive degradation of clofibric acid (CLA) in water. At cavitation number (C) 0.2, r 3.25, pH 6.5, the combined HC/SO/UV degraded 99.68 % of CLA in 90 min resulting in a synergistic effect of 1.42. Quenching experiments on SO/UV and HC/SO/UV revealed that HC promoted the formation of H radicals, which were the primary species for CLA degradation. In contrast, the effect of oxidizing species, such as HO and SO radicals was negligible. HC/SO/UV remained high degradation of CLA in the presence of co-existing CO, Cl, and SO anions. The presence of humic acids (HA) showed the strongest inhibitory effect, declining the degradation rate constant of CLA from 6.67 × 10 min to 1.34 × 10 min. The presented findings offer mechanistic insights into the reductive degradation of CLA under the novel HC/SO/UV. Based on the detected intermediates by Gas Chromatography-Mass Spectrometry (GC-MS) and density functional theory (DFT), three pathways of CLA degradation were proposed. Specifically, the reductive degradation of CLA was initiated by nucleophilic attacks of H radicals followed by cyclization, hydrogenation of the benzene ring, and fragmentation into smaller compounds, e.g., 3-methylbutanal. Importantly, developed process allows effective dehalogenation of the pollutant. Such approach can find wide applicability for degradation of other emerging organic pollutants, especially pharmaceuticals, pesticides and PFAS containing halogen atoms. This study brings a new strategy for the enhancement of SO/UV and demonstrates HC as a versatile and effective tool in water and wastewater treatment.
首次将高级还原过程（ARPs）中的SO/UV与水力空化（HC）相结合，尝试对水中的氯贝酸（CLA）进行还原降解。在空化数（C）为0.2、r为3.25、pH值为6.5的条件下，HC/SO/UV组合在90分钟内降解了99.68%的CLA，协同效应为1.42。对SO/UV和HC/SO/UV的猝灭实验表明，HC促进了H自由基的形成，而H自由基是CLA降解的主要物种。相比之下，HO和SO等氧化物种的影响可忽略不计。在共存的CO、Cl和SO阴离子存在的情况下，HC/SO/UV对CLA仍保持较高的降解率。腐殖酸（HA）的存在显示出最强的抑制作用，使CLA的降解速率常数从6.67×10⁻³ min⁻¹降至1.34×10⁻³ min⁻¹。所呈现的研究结果为新型HC/SO/UV条件下CLA的还原降解提供了机理见解。基于气相色谱-质谱联用（GC-MS）和密度泛函理论（DFT）检测到的中间体，提出了CLA降解的三条途径。具体而言，CLA的还原降解是由H自由基的亲核攻击引发的，随后发生环化、苯环氢化，并裂解成较小的化合物，如3-甲基丁醛。重要的是，所开发的工艺能够有效地使污染物脱卤。这种方法在降解其他新兴有机污染物，特别是含有卤素原子的药物、农药和全氟烷基物质方面具有广泛的适用性。本研究为增强SO/UV带来了一种新策略，并证明了HC是水和废水处理中一种通用且有效的工具。
