Preparation of yttria-stabilized ZrO2 nanofiltration membrane by reverse micelles-mediated sol-gel process and its application in pesticide wastewater treatment

Abstract 8 mol% yttria-stabilized ZrO2 (8YSZ) nanofiltration (NF) membranes were prepared from size-controlled spherical ZrO2 nanoparticles with an average diameter of ˜10 nm and a particle roundness value greater than 0.90, and the nanoparticles were efficiently fabricated by a reverse micelles (RMs)-mediated sol-gel process. It was found that yttria doping not only suppressed the tetragonal to monoclinic (t-m) phase transition, ensuring the membranes integrity, but also decreased the tetragonal grain size, increased the specific surface area, narrowed the pore size distribution and thus optimized the NF performance. The as-prepared 8YSZ NF membranes with a thickness of ˜260 nm exhibited high NF performances, while the pure water permeability and molecular weight cut-off (MWCO) were 3.9-4.2 L m−2  h-1  bar-1 and 800 ± 50 Da respectively. In the treatment of pesticide wastewater, the removal rate of carbofuran by 8YSZ NF membranes was more than 82%, while the maximum removal rate could reach 89%. Furthermore, the contaminated membranes could be restored as ever after alkali wash and low-temperature calcination, implementing multiple reuses.