Impact of nanoclays on polyvinylidene fluoride mixed matrix membranes for the efficient treatment of oily-wastewater

Abstract

Membrane technology demonstrated a sustainable methodology for water reclamation from oily-wastewater, but it is prone to fouling during longer filtration runs. In this study, fouling resistant polyvinylidene fluoride (PVDF) mixed matrix membranes (MMMs) containing nanoclays such as halloysite (HT) and montmorillonite (MMT) were fabricated for the effective treatment of oily wastewater. Phase inversion technique was followed for the fabrication of HT-PVDF and MMT-PVDF MMMs. Physiochemical characterization and filtration experiments were studied to evaluate the influence of nanoclays on PVDF membrane performance. Fourier transform infrared spectroscopy (FTIR) and morphology analyses indicated that both nanoclays are layered structured with abundant hydrophilic functional groups. The dispersions of HT and MMT were confirmed by surface morphology and topography analysis of PVDF MMMs. The hydrophilicity property was improved in HT-PVDF and MMT-PVDF MMMs, which was evident in the contact angle analysis. Among the membranes, MMT-PVDF MMMs held the higher water permeability of 2.59 x10-8 m/s.kPa. For oil-water filtration, HT-PVDF and MMT-PVDF MMMs displayed higher normalized flux with maximum rejection of more than 95%. Overall, MMT would be cost-effective nanofiller for the development of antifouling PVDF MMMs against oil-water filtration.