Effect of Particle Size Distribution of Fly Ash on Compressive Strength, Pore Size and Porosity of Geopolymeric Membrane for Car Wash Water Treatment

Particle-size distribution plays an important role in synthesis cost and overall structural parameters of geopolymeric membrane. In this research work, the effect of particle-size distribution on the pore size, porosity, and compressive strength was investigated in the synthesis of geopolymeric membranes. The average particle-size distribution of 4.30, 23.30, 46.20, 65.32, 86.24, and 98.53 mu m of fly ash was investigated separately based on pore size, porosity, and compressive strength of prepared geopolymeric membrane using sodium silicate ( Na2SiO3) and sodium hydroxide (NaOH) as a chemical activator and hydrogen peroxide (H2O2) (10 v/v %) as a pore-forming agent. Compressive strength of 13 MPa with 48% porosity and more uniform pore size has been obtained at source material with a particle-size distribution of 23.30 mu m. No significant change in the compressive strength of the prepared membrane has been observed for source material particle sizes below 23.30 mu m. The results show that there is no need for energy and cost-intensive very fine grinding below 23.30 mu m as the particles were completely dissolved in an alkaline solution. A permeate flux of 40.53 L/m(2) h and 93% rejection of total solids were reported for the membrane prepared from 23.30 mu m particle size.