Gravity-driven layered double hydroxide nanosheet membrane activated peroxymonosulfate system for micropollutant degradation

Muhammad Bilal Asif; Hongyu Kang; Zhenghua Zhang

doi:10.1016/j.jhazmat.2021.127988

Gravity-driven layered double hydroxide nanosheet membrane activated peroxymonosulfate system for micropollutant degradation

J Hazard Mater. 2022 Mar 5:425:127988. doi: 10.1016/j.jhazmat.2021.127988. Epub 2021 Dec 3.

Authors

Muhammad Bilal Asif¹, Hongyu Kang¹, Zhenghua Zhang²

Affiliations

¹ Institute of Environmental Engineering & Nano-Technology, Tsinghua-Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong, China; Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Tsinghua-Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong, China; School of Environment, Tsinghua University, Beijing 100084, China.
² Institute of Environmental Engineering & Nano-Technology, Tsinghua-Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong, China; Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Tsinghua-Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, Guangdong, China; School of Environment, Tsinghua University, Beijing 100084, China. Electronic address: zhenghua.zhang@sz.tsinghua.edu.cn.

PMID: 34891018
DOI: 10.1016/j.jhazmat.2021.127988

Abstract

For the first time in this study, CoAl-layered double hydroxide nanosheet membrane (LDH_m) with abundant active sites was fabricated for peroxymonosulfate (PMS) activation with the mindset to catalytically degrade micropollutants. Depending on the catalyst loading, the developed LDH_m can be driven under gravity at a permeate flux of approximately 80 L/m² h and 210 L/m² h at LDH loading of 0.80 mg/cm² and 0.08 mg/cm², respectively. Notably, the LDH_m (0.63 mg) exhibited excellent PMS activation efficiency as indicated by 87.8% removal of the probe chemical (ranitidine) at 0.2 mM PMS, which was higher than that (37-44%) achieved by conventional LDH (5-20 mg)/PMS (0.2 mM) system. In addition to efficient degradation of several micropollutants, LDH_m/PMS performance was not inhibited by variation in solution pH (4-8) as well as during long-term (29 h) continuous-flow operation. SO₄^•- and ¹O₂ were identified as the primary reactive species in the LDH_m/PMS system, while both Co and Al participated in PMS activation. This study offers a simple strategy for efficient removal of several micropollutants with significantly reduced catalyst leaching, which could be applied sustainably in water treatment.

Keywords: Activation mechanisms; Catalytic membrane; Layered double hydroxide; Micropollutants; Peroxymonosulfate.