Yuxin Zeng, Yaxuan Gao, Tao Guo, Lifeng Yin, Michael R. Hoffmann
{"title":"“Catch-and-feed”: Janus catalytic flow-through membrane enables highly efficient removal of micropollutants in water","authors":"Yuxin Zeng, Yaxuan Gao, Tao Guo, Lifeng Yin, Michael R. Hoffmann","doi":"10.1016/j.watres.2024.122778","DOIUrl":null,"url":null,"abstract":"Micropollutants, due to their low concentrations, exceptional chemical stability, and profound toxicity, present a significant challenge in water treatment. While electrocatalysis and photocatalysis have shown promise as potential water purification techniques, their inherent limitations in mass transfer often result in elevated energy requirements and suboptimal efficiency. In this study, a Janus catalytic flow-through membrane (JCFM) was utilized to successfully remove two notorious micropollutants dichlorvos (DDVP) and azoxystrobin (AZX) from water based on the \"catch-and-feed\" strategy. This membrane adopts a \"sandwich\" configuration, comprising platinum-modified reduced titanium (Pt@rTO) as the electrocatalytic layer, porous titanium (Ti) as the current collector, and rTO as the photocatalytic layer. The JCFM exhibited remarkable performance, maintaining an •OH energy conversion efficiency of up to 20.12 nM and displaying catalytic activity (<em>k</em><sub>JCFM</sub>=6.97 × 10<sup>–4</sup> s<sup>–1</sup>) in degrading AZX far superior to that of photocatalysis (<em>k</em><sub>PC</sub>=9.51 × 10<sup>–5</sup> s<sup>–1</sup>) or electrocatalysis (<em>k</em><sub>EC</sub>=9.89 × 10<sup>–5</sup> s<sup>–1</sup>) alone. It is evidenced that the Pt@rTO layer efficiently generates reactive oxygen species (ROS), which, along with the micropollutants, flow through the JCFM (“feed”), which strengthens mass transfer and facilitates efficient reactions within the confined space (“catch”). The ROSs then seep through the rTO layer, where they are reactivated by UV light radiation. The mechanism and the alternative reaction pathway of DDVP and AZX has also been proposed. In sequential testing, the JCFM achieved continuous and energy-efficient removal of micropollutants, exceeding 97.5% over 200 h. The scale-up application of this technology has proven effective in the treatment of secondary biochemical effluent from municipal sewage, coking wastewater, and landfill leachate, achieving the concurrent degradation of various micropollutants.","PeriodicalId":443,"journal":{"name":"Water Research","volume":null,"pages":null},"PeriodicalIF":11.4000,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Water Research","FirstCategoryId":"93","ListUrlMain":"https://doi.org/10.1016/j.watres.2024.122778","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
Micropollutants, due to their low concentrations, exceptional chemical stability, and profound toxicity, present a significant challenge in water treatment. While electrocatalysis and photocatalysis have shown promise as potential water purification techniques, their inherent limitations in mass transfer often result in elevated energy requirements and suboptimal efficiency. In this study, a Janus catalytic flow-through membrane (JCFM) was utilized to successfully remove two notorious micropollutants dichlorvos (DDVP) and azoxystrobin (AZX) from water based on the "catch-and-feed" strategy. This membrane adopts a "sandwich" configuration, comprising platinum-modified reduced titanium (Pt@rTO) as the electrocatalytic layer, porous titanium (Ti) as the current collector, and rTO as the photocatalytic layer. The JCFM exhibited remarkable performance, maintaining an •OH energy conversion efficiency of up to 20.12 nM and displaying catalytic activity (kJCFM=6.97 × 10–4 s–1) in degrading AZX far superior to that of photocatalysis (kPC=9.51 × 10–5 s–1) or electrocatalysis (kEC=9.89 × 10–5 s–1) alone. It is evidenced that the Pt@rTO layer efficiently generates reactive oxygen species (ROS), which, along with the micropollutants, flow through the JCFM (“feed”), which strengthens mass transfer and facilitates efficient reactions within the confined space (“catch”). The ROSs then seep through the rTO layer, where they are reactivated by UV light radiation. The mechanism and the alternative reaction pathway of DDVP and AZX has also been proposed. In sequential testing, the JCFM achieved continuous and energy-efficient removal of micropollutants, exceeding 97.5% over 200 h. The scale-up application of this technology has proven effective in the treatment of secondary biochemical effluent from municipal sewage, coking wastewater, and landfill leachate, achieving the concurrent degradation of various micropollutants.
期刊介绍:
Water Research, along with its open access companion journal Water Research X, serves as a platform for publishing original research papers covering various aspects of the science and technology related to the anthropogenic water cycle, water quality, and its management worldwide. The audience targeted by the journal comprises biologists, chemical engineers, chemists, civil engineers, environmental engineers, limnologists, and microbiologists. The scope of the journal include:
•Treatment processes for water and wastewaters (municipal, agricultural, industrial, and on-site treatment), including resource recovery and residuals management;
•Urban hydrology including sewer systems, stormwater management, and green infrastructure;
•Drinking water treatment and distribution;
•Potable and non-potable water reuse;
•Sanitation, public health, and risk assessment;
•Anaerobic digestion, solid and hazardous waste management, including source characterization and the effects and control of leachates and gaseous emissions;
•Contaminants (chemical, microbial, anthropogenic particles such as nanoparticles or microplastics) and related water quality sensing, monitoring, fate, and assessment;
•Anthropogenic impacts on inland, tidal, coastal and urban waters, focusing on surface and ground waters, and point and non-point sources of pollution;
•Environmental restoration, linked to surface water, groundwater and groundwater remediation;
•Analysis of the interfaces between sediments and water, and between water and atmosphere, focusing specifically on anthropogenic impacts;
•Mathematical modelling, systems analysis, machine learning, and beneficial use of big data related to the anthropogenic water cycle;
•Socio-economic, policy, and regulations studies.