Polythiophene incorporated polysulfone blend membranes for effective removal of zinc and iron from electroplating effluent: Experimental studies and performance modelling

Abstract

Polythiophene (pTh) was doped in a polysulfone (Psf) matrix to form ultrafiltration (UF) grade blend membranes. The membranes showed negative surface potential at neutral pH condition (zeta potential: −18 mV for membrane M-0.5 at pH 7) along with good adsorption capacities for various heavy metals. The optimum membrane M-0.5 (with 0.5 wt% pTh concentration) had the highest heavy metal selectivity (adsorption capacities of 81, 64.4, 59 and 51 mg/g for lead, iron, zinc and copper ions, respectively) with a permeability of 4.92 × 10^-11 m/Pa.s. Furthermore, the potential of the blend M-0.5 membrane was investigated for the reduction of Zn(II) and Fe(II) from an electroplating effluent using a two-stage UF to reduce metal ion concentration below the dischargeable limit. The membrane M-0.5 had a breakthrough time of 16 h for the synthetic solution and 10 h for the 2^nd stage of industrial wastewater. A two-dimensional multicomponent transient convective-adsorption model was utilized to predict the membrane performance.