Flat ceramic microfiltration membrane based on natural clay and Moroccan phosphate for desalination and industrial wastewater treatment

Abstract

A new microfiltration ceramic membrane has been developed by uniaxially compressing natural Moroccan materials: red clay of Safi and natural phosphate of Youssoufia, which is rich in organic matter. The natural phosphate can be beneficial to porosity formation. The effects of natural phosphate on the morphological and flexural strength of the flat disks sintered at 1100°C were studied to identify the optimal mass ratio of clay and phosphate via X-ray diffraction, scanning electron microscopy and flexural strength testing. The optimal composition of the flat ceramic membrane contained 40wt% natural phosphate, which led to a linear thermal expansion coefficient less than 13.42×10−6°C−1, flexural strength of 17.5MPa and Young's modulus of 40.12GPa. The average pore diameter and water permeability of the obtained ceramic membrane were respectively 2.5μm and 928L/(h·m2·bar). The microfiltration membrane efficiency was evaluated by filtering three feed solutions types: a tannery beamhouse effluent, a raw seawater and a synthetic solution of aluminium chloride (at high pH). The obtained ceramic membrane exhibited superior turbidity removal efficiency for all studied feeds: effluent (99.80%), seawater (99.62%) and synthetic solution (99.86%). Moreover, this microfiltration membrane showed good microstructure and mechanical stability after filtration experiments.