Metakaolin-based Geopolymer Microfiltration Membrane for Removing Dye with Oil Emulsion Method

Geopolymeric membranes were prepared by activating metakaolin using sodium hydroxide and silica fume solutions. The membrane was characterized using X-ray diffraction, Scanning electron microscopy, Fourier transform infrared spectroscopy, mercury intrusion porosimetry, and energy dispersion spectroscopy. The geopolymeric membrane had a porosity percentage of 33.5 and an average pore size of 327.67 nm. The cationic dye methylene blue was removed by emulsion filtration using this membrane. The dye binds to sodium dodecyl sulfate (SDS) as an anionic surfactant and then dissolves in the oil phase of the emulsion. So the dye is extracted from the aqueous solution, and the microfiltration membrane removes the emulsion droplets. The Box-Behnken experimental design was used to optimize the membrane separation performance. Results showed that the permeability was 70.28 L/m2</sup>.h.bar under the optimized conditions and a dye removal efficiency of 98.45% was achieved at a feed flow rate of 1.5 l/min, an SDS content of 5.33 %, and a methylene Blue concentration of 100 ppm.