Efficient degradation of sulfamethoxazole by CoCu LDH composite membrane activating peroxymonosulfate with decreased metal ion leaching

In this study, we prepared two types of composite membranes decorated with CoCu layered double hydroxide (LDH) nanoparticles, i.e. LDH@Calotropis gigantean fiber (LDH@CGF) and LDH@polyvinylidene fluoride (LDH@PVDF) for the first time. Besides, the application potential of different types of composite functional membranes based on LDH in PMS activation system was compared. Both of the LDH-based composite membranes exhibited excellent activity in peroxymonosulfate (PMS) activation process. More importantly, the composite membrane could be separated from the treated water to meet the need of practical application. The superior composite membrane was identified as LDH@PVDF, which was with excellent PMS activation capability and pretty lower metal ions leaching concentration (cobalt 0.044 mg L-1, copper 0.026 mg L-1). And then, LDH@PVDF was employed to investigate the PMS activation performance in various pharmaceutical pollutants removal processes. Besides, the activity of LDH@PVDF for SMX degradation in real aquatic environment (tap water and wastewater) was detected, proving the wide practical applicability of LDH@PVDF membrane. Finally, the possible SMX degradation pathway and PMS activation mechanism occurring in LDH-based composite membrane/PMS system were proposed. Hence, this study for LDH-based membranes construction may provide new insights into the environmentally-friendly catalytic membranes preparation and practical application in wastewater treatment.

Automated summary

This study prepared two types of composite membranes using CoCu layered double hydroxide (LDH) nanoparticles and compared their application potential in peroxymonosulfate (PMS) activation system, where LDH@PVDF membrane exhibited excellent PMS activation capability and low metal ions leaching concentration. The practical applicability of LDH@PVDF membrane in pharmaceutical pollutants removal processes was demonstrated through real aquatic environment testing, providing new insights into environmentally-friendly catalytic membrane preparation and practical application in wastewater treatment.