Title: Preparation and characterization of hybrids of cellulose acetate membranes blended with polysulfone and embedded with silica for Copper (II), Iron (II) and Zinc (II) removal from contaminated solutions

Abstract

With the objective to assess the suitability of cellulose acetate (CA), polysulfone (PSF) and silica (SiO 2 ) for wastewater treatment, this work presents the results of preparation and characterization of PSF blended CA hybrid filtration membranes (CA/PSF) as well as PSF blended and SiO 2 embedded CA hybrid adsorption membranes (CA/PSF-SiO 2 ) for copper (II), iron (II) and zinc (II) ions removal from contaminated aqueous solutions. The membranes were prepared by phase inversion, using granules of CA, PSF and SiO 2 dissolved in N, N Dimethyl formamide (DMF). From the scanning electron microscopy (SEM) used to determine the morphology of the membranes, different pore sizes are seen at their rough surfaces and cross sections. The porosity and pore sizes of the membranes, determined by differentiation varied from 26.8±0.3 to 81.1±0.3 µm and 1.26 to 1.38%, respectively. The contact angles of the membranes ranged between 49 and 76° on their glass side while their ranged between 56 and 77° on their air side. The hybrid filtration polymer membranes allowed the uptake of more than 90% of the metal ions initially present in the contaminated solutions which were concentrated at 40 mg L -1. Adsorption experiments were carried out with CA/PSF-SiO 2 membranes. The adsorption capacity of these compounds was shown to be higher than numerous other literatureknown adsorbents, reaching 70 mg g -1 for CA/PSF 85/15-SiO 2 towards Cu (II). Finally, by coupling adsorption with ultrafiltration in the tangential mode, the removal of Cu (II), Fe (II) and Zn (II) was found to be improved, allowing to reach a removal efficiency of 95% towards Cu (II) at a metal concentration of 60 mg L -1, and a promising removal efficiency around 98% at a very high metal concentration of 900 mg L-1.