Improvement of Oil/Water Emulsion Separation Efficiency Using Modified ?-Alumina Membranes with Ludox Colloidal Silica Nanoparticles

Ghader Mahmodi ^a, Anirban Ghosh ^a, Michael Miranda^a, Clint Aichele ^a*, and Seok-Jhin Kim ^a*

^a School of Chemical Engineering, Oklahoma State University, 420 Engineering North, Stillwater, OK, 74078, United States

This study focuses on the surface modification of α-alumina ultrafiltration(UF) membranes incorporating Ludox colloidal silica (spherical hydrophilic silica) in order to enhance membrane fouling-restatement during separation of oil/water emulsions process. The alumina membrane treated with silica-nanoparticle solution of varied silica loading from 0.025% to 3 wt.%. The impacts of various weight percentages of silica nanoparticles on the surface properties, membrane morphology, membrane flux and separation performance of the membranes were investigated. The ATR-FTIR, SEM, EDX, WCA, and AFM analyses were applied to characterize the pristine α-alumina and modified membranes. The tubular membrane was sealed into the stainless steel module of a cross-flow system. Experiments were carried out with the tubular membrane module with a membrane surface area of 16.2 cm² at room temperature. Oil-in-water emulsions was added to the feed tank. The setup consists of a 37.8 L feed tank equipped with a Stenner Peristaltic Metering Pumps (USA) to pump the feed to the membrane module. The preliminary results showed that the modification method led to significant enhancement of the surface hydrophilicity, improvement of fouling-resistant property and oil/water emulsion flux for the alumina membrane treated with a 0.5 wt.% silica-nanoparticle solution.