APTES-functionalized MoS₂@ZnO nanocomposite for ultrafiltration: Advanced characterization and oil/water separation performance

Oily wastewater, generated from industrial processes and petroleum-related activities, contains hazardous pollutants that threaten environmental and water quality. Efficient treatment is essential to minimize these risks and ensure sustainable water management. This study focuses on developing polyether sulfone (PES)-based ultrafiltration (UF) membranes incorporated with molybdenum disulfide (MoS₂) coated with zinc oxide (ZnO) nanoparticles and functionalized with amine and silanol groups (i.e., originated from (3-aminopropyl)triethoxysilane (APTES)), specifically designed for the purification of oil/water mixtures. This study primarily aims to address the issue of nanoparticle agglomeration by improving the uniform dispersion of the nanocomposite throughout the membrane via functionalization. The influence of varying concentration (0.5–4 wt%) of APTES-MoS₂@ZnO composite was investigated, both on the properties and performance. The modified membranes exhibited enhanced properties and performance, with the membrane containing 2 wt% of APTES-MoS₂@ZnO (UF02) achieving the highest pure water permeance of 398.4 LMH/bar, 1.8 times greater than the unmodified membrane (UF00). Furthermore, UF02 demonstrated a flux recovery ratio of 80.2 %, compared to 67.1 % for UF00, highlighting its superior fouling resistance. The enhanced antifouling properties are also confirmed by reduced irreversible (UF00: 32.9 % to UF02: 19.8 %) and enhanced reversible (UF00: 23.0 % to 32.8 %) fouling ratios. The membranes demonstrated over 99.9 % rejection of oil, COD, and turbidity. UF02 also demonstrated stability across both acidic and alkaline pH conditions, as well as durability over extended filtration cycles. Additionally, UF02 was tested with real grey wastewater, delivering promising filtration results. These findings underscore the potential of APTES-MoS₂@ZnO-modified PES membranes for diverse water treatment applications.