Low-cost composite ultrafiltration membrane made from TiO2 and nanocomposite clay materials over zeolite support for oily wastewater purification and heavy metals removal

Abstract

A novel composite ultrafiltration membrane Sm-Ti/Z 3 was developed by deposition of active layer made from 70% of TiO2/Smectite nanocomposite (Sm NC) and 30% commercial TiO2 nanoparti-cles (Ti NP) on ceramic zeolite support previously prepared, using the layer-by-layer technique. The characteristics and the morphology of the membrane sintered at 900°C were determined by Brunauer–Emmett–Teller and scanning electron microscopy. A membrane without cracks and show-ing homogeneous surface and good adhesion on the support was achieved. The characteristics of the membrane were a mean pore diameter of 16 nm and a water permeability of 95 L/h m2 bar. The application of this membrane to the purification of oily effluent shows good performance in terms of permeate flux and pollutants removal with almost total retention of chemical oxygen demand, oil and turbidity. In addition, Sm-Ti/Z 3 membrane displayed an important removal of the conductivity beyond 46%. This result is explained by the high elimination of heavy metals (>96%) such as copper, plumb and zinc. The performances of the new membrane suggest also its potential application for remediation of oily wastewater contaminated with heavy metals.