Quenching Residual H2o2 From Uv/H2o2 With Granular Activated Carbon: A Significant Impact Of Bicarbonate

作     者：Zeng, Jinfeng Zhang, Miao Qin, Xinxin He, Yi Liu, Xinyue Zhu, Yichun Liu, Zuwen Li, Wentao Dong, Huiyu Qiang, Zhimin Lian, Junfeng 

作者机构：Jiangxi Provincial Key Laboratory of Water Ecological Conservation at Headwater Regions Jiangxi University of Science and Technology 1958 Ke-jia Road Ganzhou341000 China Ganzhou Key Laboratory of Basin Pollution Simulation and Control Jiangxi University of Science and Technology 1958 Ke-jia Road Ganzhou341000 China National－local Joint Engineering Laboratory of Water Engineering Safety and Efficient Utilization of Resources in Poyang Lake Watershed Nanchang Institute of Technology Nanchang330099 China KeyLaboratoryofDrinkingWaterScienceandTechnology ResearchCenterforEcoEnvironmental Sciences Chinese Academy of Sciences 18 Shuang-qing Road Beijing100085 China Hydrology and Water Resources Monitoring Center for Ganjiang Upstream Watershed 8 Zhang-jia-wei Road Ganzhou341000 China 

出 版 物：《SSRN》 

年 卷 期：2023年

核心收录：

主　　题：Sulfur compounds 

摘      要：UV/H2O2 has been used as an advanced oxidation process to remove organic micropollutants from drinking water. Residual H2O2 should be quenched to avoid potential damage to the distribution system or disinfectant wastage during the subsequent chlorination/chloramination process. Granular activated carbon (GAC) filter can quench the residual oxidant and eliminate some of the dissolved organic matter. However, knowledge on the kinetics and governing factors of GAC quenching of residual H2O2 from UV/H2O2 and the mechanism underlying the enhancement of the process by HCO3– is limited. Therefore, this study aimed to analyse the kinetics and influential factors, particularly the significant impact of bicarbonate (HCO3–). H2O2 decomposition by GAC followed first-order kinetics, and the rate constants normalised by the GAC dosage (kn) were steady (1.6 × 10–3 L g–1 min–1) with variations in the GAC dosage and initial H2O2 concentration. Alkaline conditions favour H2O2 quenching. Basic groups of the GAC contributed more to H2O2 quenching than did acidic groups, with their specific kn values being 8.9 and 2.4 min–1 M–1, respectively. The presence of chloride, sulphate, nitrate, and dissolved organic matter inhibited H2O2 quenching, while HCO3– promoted it. The interfacial hydroxyl radical (HO•) zones were visualised on the GAC surface, and HCO3– addition increased the HO• concentration. HCO3– increased the concentration of persistent free radicals (PFRs) on the GAC surface, which mainly contributed to HO• generation. A significant enhancement of HCO3– on H2O2 quenching by GAC was also verified in real water. This study revealed the synergistic mechanism of HCO3– and GAC on H2O2 quenching and presents the potential applications of residual H2O2 in the H2O2-based oxidation processes. © 2023, The Authors. All rights reserved.