Huaijia Xin, Wei Zhang, Xiaofeng Zhang, Gong Zhang, Qinghua Ji, Huijuan Liu, Jiuhui Qu
{"title":"Energy Recovery from Hexavalent Chromium Reduction for In Situ Electrocatalytic Hydrogen Peroxide Production","authors":"Huaijia Xin, Wei Zhang, Xiaofeng Zhang, Gong Zhang, Qinghua Ji, Huijuan Liu, Jiuhui Qu","doi":"10.1021/acs.est.4c03827","DOIUrl":null,"url":null,"abstract":"Recovering chemical energy embedded in pollutants is significant in achieving carbon-neutral industrial wastewater treatment. Considering that industrial wastewater is usually treated in a decentralized manner, <i>in situ</i> utilization of chemical energy to achieve waste-to-treasure should be given priority. Herein, the chemical energy released by the electroreduction of Cr(VI) was used to enhance on-site H<sub>2</sub>O<sub>2</sub> generation in a stacked flow-through electrochemical system. The driving force of water flow efficiently coupled O<sub>2</sub> evolution with 2-e O<sub>2</sub> reduction to facilitate H<sub>2</sub>O<sub>2</sub> generation by transporting anode-produced O<sub>2</sub> to the cathode. Meanwhile, the chemical energy released by Cr(VI) promoted O<sub>2</sub> evolution and impeded H<sub>2</sub> evolution by regulating the electrode potentials, accounting for the enhanced H<sub>2</sub>O<sub>2</sub> generation. The system could completely reduce 10–100 ppm of Cr(VI), reaching the maximum H<sub>2</sub>O<sub>2</sub> concentration of 2.41 mM. In particular, the H<sub>2</sub>O<sub>2</sub> concentrations in the Cr(VI)-containing electrolyte were 10.6–88.1% higher than those in the Cr(VI) free electrolyte at 1.8–2.5 V. A 24-day continuous experiment demonstrated the high efficiency and stability of the system, achieving a 100% reduction efficiency for 100 ppm of Cr(VI) and producing ∼1.5 mM H<sub>2</sub>O<sub>2</sub> at 1.8 V. This study presents a feasible strategy for Cr(VI) detoxification and synchronous on-site H<sub>2</sub>O<sub>2</sub> generation, providing a new perspective for innovative Cr(VI) wastewater treatment toward resource utilization.","PeriodicalId":36,"journal":{"name":"环境科学与技术","volume":null,"pages":null},"PeriodicalIF":10.8000,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"环境科学与技术","FirstCategoryId":"1","ListUrlMain":"https://doi.org/10.1021/acs.est.4c03827","RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, ENVIRONMENTAL","Score":null,"Total":0}
引用次数: 0
Abstract
Recovering chemical energy embedded in pollutants is significant in achieving carbon-neutral industrial wastewater treatment. Considering that industrial wastewater is usually treated in a decentralized manner, in situ utilization of chemical energy to achieve waste-to-treasure should be given priority. Herein, the chemical energy released by the electroreduction of Cr(VI) was used to enhance on-site H2O2 generation in a stacked flow-through electrochemical system. The driving force of water flow efficiently coupled O2 evolution with 2-e O2 reduction to facilitate H2O2 generation by transporting anode-produced O2 to the cathode. Meanwhile, the chemical energy released by Cr(VI) promoted O2 evolution and impeded H2 evolution by regulating the electrode potentials, accounting for the enhanced H2O2 generation. The system could completely reduce 10–100 ppm of Cr(VI), reaching the maximum H2O2 concentration of 2.41 mM. In particular, the H2O2 concentrations in the Cr(VI)-containing electrolyte were 10.6–88.1% higher than those in the Cr(VI) free electrolyte at 1.8–2.5 V. A 24-day continuous experiment demonstrated the high efficiency and stability of the system, achieving a 100% reduction efficiency for 100 ppm of Cr(VI) and producing ∼1.5 mM H2O2 at 1.8 V. This study presents a feasible strategy for Cr(VI) detoxification and synchronous on-site H2O2 generation, providing a new perspective for innovative Cr(VI) wastewater treatment toward resource utilization.
期刊介绍:
Environmental Science & Technology (ES&T) is a co-sponsored academic and technical magazine by the Hubei Provincial Environmental Protection Bureau and the Hubei Provincial Academy of Environmental Sciences.
Environmental Science & Technology (ES&T) holds the status of Chinese core journals, scientific papers source journals of China, Chinese Science Citation Database source journals, and Chinese Academic Journal Comprehensive Evaluation Database source journals. This publication focuses on the academic field of environmental protection, featuring articles related to environmental protection and technical advancements.