Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission & Ministry of Education, Hubei Province, PR China; College of Resource and Environmental Science, South-Central University for Nationalities, Wuhan, 430074, PR China.
Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission & Ministry of Education, Hubei Province, PR China; College of Resource and Environmental Science, South-Central University for Nationalities, Wuhan, 430074, PR China.
Chemosphere. 2021 Jul;274:129654. doi: 10.1016/j.chemosphere.2021.129654. Epub 2021 Jan 29.
Organochlorine pesticides are widespread in soils, sediments and even in groundwater, causing great concern to human health because of its toxicity and carcinogenic effects. The remarkable mineralization and lowered toxicity are particularly important during the removal of organochlorine pesticides. In this study, Pd/CeO was prepared and employed as a bifunctional catalyst, to construct the reduction-oxidation series coupling Electro-Fenton (EF) system. The removal of chlorophenols (CPs) reached over 95% within 10 min at pH 3.0 and a current density of 25 mA/cm in Pd/CeO-EF system. The second-order rate constant of CPs degradation was 10.28 L mmolmin in Pd/CeO-EF system, which was 29 times as fast as the sum of electrolysis with Pd/CeO (0.24 L mmolmin) and EF (0.11 L mmolmin). Dehydrochlorination by Pd [H] contributed to the removal of CPs in Pd/CeO-EF system. The generated reactive oxygen species, mainly OH was also confirmed by ESR to contribute to the removal of CPs. The reduction-oxidation series coupling degradation of CPs in Pd/CeO-EF system increased the TOC removal to 70% in 360 min. The analysis of intermediate products further revealed the reductive and oxidative products in Pd/CeO-EF. Moreover, the system of Pd/CeO-EF exhibited an excellent performance treatment for CPs in actual groundwater. This study provides a new stratagem to eliminate organochlorine pesticides in groundwater environments rapidly and thoroughly.
有机氯农药广泛存在于土壤、沉积物甚至地下水中，由于其毒性和致癌作用，对人类健康造成了极大的关注。在去除有机氯农药的过程中，其显著的矿化和降低毒性尤为重要。在本研究中，制备了 Pd/CeO 并将其用作双功能催化剂，构建了还原-氧化串联偶联电-Fenton（EF）体系。在 pH 3.0 和电流密度为 25 mA/cm 的条件下，Pd/CeO-EF 体系中氯酚（CPs）在 10 min 内的去除率超过 95%。CPs 降解的二级反应速率常数在 Pd/CeO-EF 体系中为 10.28 L mmolmin，是 Pd/CeO 电解（0.24 L mmolmin）和 EF（0.11 L mmolmin）之和的 29 倍。Pd [H] 的脱氯作用有助于 Pd/CeO-EF 体系中 CPs 的去除。通过 ESR 也证实了生成的活性氧物质，主要是 OH，有助于 CPs 的去除。Pd/CeO-EF 中的还原-氧化串联降解反应提高了 TOC 在 360 min 内的去除率达到 70%。中间产物的分析进一步揭示了 Pd/CeO-EF 中的还原和氧化产物。此外，Pd/CeO-EF 体系对实际地下水中的 CPs 具有优异的处理性能。本研究为快速彻底消除地下水中的有机氯农药提供了一种新策略。
