PES/PVP/TiO2 mixed matrix hollow fiber membrane with antifouling properties for humic acid removal

Abstract

The aim of this study is to analyse the fouling behaviour of polyethersulfone (PES) / polyvinyl pyrrolidone (PVP) / titanium oxide (TiO2) mixed matrix (MM) hollow fiber (HF) membrane with varying TiO2 loadings for humic acid (HA) treatment. The MM HF membrane was fabricated using dry jet – wet phase inversion method by blending varying amount of TiO2 nanoparticles (1, 2, 3, and 4 wt. %) into the PES dope solution. The fabricated HF membrane was characterised in terms of their surface and cross section morphology, contact angle, pore size, and porosity. These characteristics can highly affect the membrane antifouling behaviour as well as membrane flux. The membrane was tested using 50 mg/L of HA solution adjusted to pH 7.7. All MM HF membranes suggested better antifouling with S2 sample at 2 wt.% TiO2 having optimal antifouling and flux performance with the lowest value for resistance by fouling and less than 5% difference from the best permeate flux and rejection values. Under this formulation, HA permeation test has registered an improved membrane flux at 23.851 kg/m2 h and HA rejection of 97.89%; an improvement of 28.9% and 3.8% respectively as compared to the neat PES membrane. HA rejection increased drastically due to higher surface hydrophilicity of TiO2 blended membranes, which repels the hydrophobic HA and prevented the adsorption of HA onto the membrane surface. This also minimize the formation of reversible and irreversible fouling by HA, which increases its antifouling abilities.