Removal of Chromium Ions from Contaminated Water Solutions by Filtration Process Using Inorganic Membrane Developed by Slip Casting Method on Tubular Ceramic Supports

Abstract

Inorganic membrane was prepared from local raw materials using slip casting technique. Characterizations of prepared tubular samples have been made by mercury inclusion porosimetry (MIP), scanning electron microscopy (SEM), UV-visible spectrometer, water permeability plant and stream potential measurements. The obtained values are mean pores radius (10 nm), water permeability (1000 L m^–2 h^–1 MPa^–1) and stream potential (–52 mV); these values clearly indicate the possibility of using this inorganic membrane in microfiltration, ultrafiltration and/or pre-nanofiltration processes. Results from filtration operation applied to chromium (Cr(III)) contaminated water: retention R(%) = 82% and estimated surface charge –66.7 mC m⁻² show the important capacity of membrane to separate chromium ions from contaminated waters. Donnan equilibrium mechanism between membrane surface charge and solute ions has been proposed to explain the selective rejection behaviour of ions by inorganic membrane.