Dachao Lin, Xinxu Shen, Caiwei Tan, Han Zhang, Rui Chen, Xing Du, Heng Liang
{"title":"Establishing electro-functionalized gravity-driven ceramic membrane filtration (EGDCM) for decentralized treatment of algae-laden brackish water: comparison of in-situ electro-oxidation and ex-situ electro-coagulation","authors":"Dachao Lin, Xinxu Shen, Caiwei Tan, Han Zhang, Rui Chen, Xing Du, Heng Liang","doi":"10.1016/j.watres.2024.122940","DOIUrl":null,"url":null,"abstract":"Algae-laden brackish water (ABW) has remarkably threatened drinking water safety in warm coastal areas. Although gravity-driven ceramic membrane filtration (GDCM) exhibits high potential in ABW treatment during decentralized water supply, membrane fouling is still a critical problem. Herein, GDCM was skillfully electro-functionalized (EGDCM) by <em>in-situ</em> electro-oxidation (ISEO) based on self-fabricated Ti/SnO<sub>2</sub>-Sb dimensionally stable anode (DSA) (EO-EGDCM) and <em>ex-situ</em> electro-coagulation (ESEC) based on iron anode (EC-EGDCM) in this study. EO-EGDCM with KMnO<sub>4</sub> augment (MnEO-EGDCM) was also established for comparison. Results show that ISEO increased GDCM membrane permeability by 22%, while EC-EGDCM membrane flux was nearly 4.8 times that of GDCM. ISEO enhanced the early removal of organic pollution, and KMnO<sub>4</sub> facilitated the active chlorine oxidization of ammonia and algal toxins on electrified Ti/SnO2-Sb DSA by suppressing the transformation of free chlorine to less reactive chloramines. Both algae cell permeabilization and intracellular organic matter release were enhanced by ISEO. But SEM-EDS, CLSM and biomass analysis evidenced that membrane biological process, which was improved by 32%∼323% by electrical stimulation, developed porous structures in the fouling layer in EO-EGDCM/MnEO-EGDCM. According to energy consumption and carbon emissions evaluation, GDCM was confirmed as an energy-saving system for treating ABW with the consumption of only 3.47×10<sup>−3</sup> kWh/m<sup>3</sup>. Electricity demand was increased for EGDCM but still considerably lower than that for other algae-laden water treatment processes. EC-EGDCM reduced energy consumption and carbon emission by around 80% compared to EC-EGDCM/MnEO-EGDCM. Electro-functionalization was a promising option to improve GDCM treatment of ABW via multiple mechanisms but further optimization was still required.","PeriodicalId":443,"journal":{"name":"Water Research","volume":"20 1","pages":""},"PeriodicalIF":11.4000,"publicationDate":"2024-12-09","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.2024.122940","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
Algae-laden brackish water (ABW) has remarkably threatened drinking water safety in warm coastal areas. Although gravity-driven ceramic membrane filtration (GDCM) exhibits high potential in ABW treatment during decentralized water supply, membrane fouling is still a critical problem. Herein, GDCM was skillfully electro-functionalized (EGDCM) by in-situ electro-oxidation (ISEO) based on self-fabricated Ti/SnO2-Sb dimensionally stable anode (DSA) (EO-EGDCM) and ex-situ electro-coagulation (ESEC) based on iron anode (EC-EGDCM) in this study. EO-EGDCM with KMnO4 augment (MnEO-EGDCM) was also established for comparison. Results show that ISEO increased GDCM membrane permeability by 22%, while EC-EGDCM membrane flux was nearly 4.8 times that of GDCM. ISEO enhanced the early removal of organic pollution, and KMnO4 facilitated the active chlorine oxidization of ammonia and algal toxins on electrified Ti/SnO2-Sb DSA by suppressing the transformation of free chlorine to less reactive chloramines. Both algae cell permeabilization and intracellular organic matter release were enhanced by ISEO. But SEM-EDS, CLSM and biomass analysis evidenced that membrane biological process, which was improved by 32%∼323% by electrical stimulation, developed porous structures in the fouling layer in EO-EGDCM/MnEO-EGDCM. According to energy consumption and carbon emissions evaluation, GDCM was confirmed as an energy-saving system for treating ABW with the consumption of only 3.47×10−3 kWh/m3. Electricity demand was increased for EGDCM but still considerably lower than that for other algae-laden water treatment processes. EC-EGDCM reduced energy consumption and carbon emission by around 80% compared to EC-EGDCM/MnEO-EGDCM. Electro-functionalization was a promising option to improve GDCM treatment of ABW via multiple mechanisms but further optimization was still required.
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.