Thermal treatment of clay-based ceramic membranes for microfiltration of Acutodesmus obliquus

Abstract Tubular ceramic microfiltration membranes were prepared by extruding thermally treated clay (TC) and raw clay to form a porous tubular membrane with the addition of cationic manioc starch and toasted manioc flour. The influence of an applied thermal treatment on the proprieties of the clay and the microfiltration membranes was characterized by measuring the particle size distribution, pore size distribution, and mechanical strength and by conducting X-ray fluorescence analysis, X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, and differential scanning calorimetry. The membranes were used for microfiltration of Acutodesmus obliquus microalgae with various applied pressures in the range of 2 × 104–1 × 105 Pa with a volumetric flow rate of 6.94 × 10− 5 m3·s− 1 at a temperature of 10 ± 5 °C. The efficiency of each of the ceramic membranes was evaluated in terms of the permeate flux for water and microalgae and the microalga retention. The addition of TC to the membrane resulted in an optimal microalga permeate flux of 3.24 × 10− 2 kg·m− 2·s− 1 and a microalga retention of 98.3% at 4 × 104 Pa and had positive impacts on the other proprieties measured. Overall, these results demonstrate a potential application of TC in ceramic membranes for crossflow microfiltration processes.