Development of clayey ceramic membranes prepared with bio-based additives: Application in water and textile wastewater treatment

Abstract

Eco-friendly ceramic membranes have been developed from clayey materials mixed with biobased additives (woodworking waste and rice husk) as pore-forming agents. Heated blends of two clayey occurring materials with the biobased additives (up to 20 wt%) were investigated using X-Ray Fluorescence spectrometry (XRF), X-Ray Diffraction (XRD), Thermogravimetric Analysis (TDA-TG), Mercury Porosimetry, Scanning Electron Microscopy/Energy Dispersive Spectroscopy (SEM-EDS) and Filtration tests. The effect of adding the pore-forming agent on the physical and mechanical properties (apparent density, apparent porosity, average pore diameter and compressive Strength) was assessed and the results were interrelated to the microstructural changes. The mineralogical analyzes showed that original minerals together with thermal decomposition products were involved in the neoformation process. SEM observations displayed the appearance of several pores with various shapes, sizes and features corresponding to the neoformed phases (gehlenite and albite) and localized heterogeneous aspects. The experimental filtration tests have clearly shown the elimination of turbidity and suspended matter with the reduction of the chemical/biological oxygen demand and the dye concentration. Thereby, it was confirmed that ceramic membranes intended for filtration with homogenous morphological aspect, good physical properties and high mechanical strength could be manufactured and used in industrial wastewater treatments.