Efficient removal of micropollutants from low-conductance surface water using an electrochemical Janus ceramic membrane filtration system

• Published in: Water research (Oxford) Vol. 220; p. 118627
• Main Authors: Li, Zhouyan, Li, Xuesong, Li, Yang, Li, Jiayi, Yi, Qiuying, Gao, Fei, Wang, Zhiwei
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15.07.2022
• Subjects: Ceramic membrane; Electrochemical membrane filtration; Hydroxyl radical; Micropollutant removal; Water treatment; Micropollutant removal; Ceramic membrane; Water treatment; Electrochemical membrane filtration; Hydroxyl radical
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2022.118627

•A janus fe-pt ceramic membrane was successfully fabricated via sputter coating.•Hydroxyl radicals generated on bilateral sides of janus membrane were dominant ROS.•Removal efficiency of atrazine was maintained in low-conductance wastewater.•A stable removal of atrazine from real surface water was achieved with EMF.•Atrazine was effectively degraded by the EMF system with janus membrane. Electrochemical membrane filtration (EMF) technology is effective to remove the micropollutant in the wastewater but its efficacy is drastically compromised in treating the surface water having a typically low conductivity. In this work, a Janus Fe-Pt electrochemical ceramic membrane (ECM) was fabricated by depositing a thin Fe layer on the side of a ceramic membrane facing feed (cathode) and Pt layer on the other side facing permeate (anode). The low Fe-Pt electrode distance (∼1 mm) ensured a decent conductance of the EMF system even in the low-salinity surface water and thereby maintained the removal efficiency of the micropollutant. It was identified that hydroxyl radicals (•OH) generated via anodic water oxidation and cathodic heterogenous Fenton process on bilateral sides of ECM were the dominant reactive oxygen species. The EMF system not only achieved 74% removal of atrazine (ATZ) from the low-conductance synthetic surface water with a low energy consumption (3.6 Wh per gATZ or 7.2 Wh m − 3), but also realized a stable removal of ATZ from real surface water over a continuous filtration experiment of 168 h. The theoretical computations and experimental analysis identified the degradation pathway, i.e., the dechlorination and dealkylation of ATZ in the EMF system. This study highlights the great potential of the Janus ECM in removing micropollutants from low-conductance surface water and wastewater. [Display omitted]