Ahmad Azari

In this study, seawater from the Shoghab region of Bushehr (Persian Gulf) was treated using a disc-shaped ceramic membrane and the microfiltration method to reduce turbidity. The disc ceramic membranes were fabricated based on kaolin with four different weight percentages of zinc oxide using the dry pressing technique. Among the fabricated samples, the one with the highest permeate flux was coated with a chitosan solution using the dip-coating method. Since seawater is used for desalination and drinking purposes, pretreatment and turbidity reduction are critically important for reverse osmosis systems. The disc membranes, 5 cm in diameter and 5 mm in thickness, were sintered in an electric furnace. Structural characterizations of the membranes included porosity, average pore size, shrinkage test, chemical resistance, SEM, TGA, AFM, FTIR, and XRD analyses were performed on the membranes. The water flux performance using both distilled water and seawater, as well as the turbidity removal efficiency, were evaluated. The final results demonstrated that the fabricated membranes were effective in turbidity removal. Specifically, the membrane containing 5 wt% zinc oxide achieved 99% turbidity removal from seawater with an initial flux of 560 L/m²·h·bar. However, the chitosan-coated membrane was not effective due to a significant reduction in permeate flux. To determine the optimal membrane, a balance between water flux and turbidity removal efficiency was considered. Ultimately, the membrane with 15 wt% zinc oxide, 32.9% porosity, an average pore size of 1.396 µm, a flux of 800 L/m²·h·bar, and 98.43% turbidity removal was identified as the optimal choice.