Synergistic design of polylactic acid/functionalized multi-walled carbon nanotubes composite membrane for enhanced oil-water separation

The increasing concerns over environmental pollution and the discharge of oily wastewater have prompted the development of advanced technologies for efficient water treatment. In this study, mixed matrix polymeric polylactic acid (PLA)/Amino-SiO₂ functionalized multi-walled carbon nanotubes (f-MWCNTs) membrane was fabricated by phase inversion at different nanoparticle loadings for the treatment of oily wastewater. The membranes were evaluated for their oil-water separation efficiency, flux, and flux recovery using synthetic oily wastewater as a model system. The experimental results revealed that the addition of a 0.5 wt% of f-MWCNTs in the mixed matrix solution significantly enhanced water permeability, resulting in a 75% improvement, while achieving about 100% oil rejection. The flux recovery of membranes loaded with 0.5 wt% f-MWCNTs exhibited a flux recovery of 60% compared to the initial value. After two cyclic flux study, pristine membranes showed a flux recovery of 11%, while the modified membranes achieve a flux recovery of approximately 42%. Taking advantage of the recyclable and biocompatible properties of PLA, this study presents a promising development and application of environmentally friendly, sustainable membranes for the effective separation of oil-water emulsions.