A study on the efficient separation of oily water using mullite whiskers membrane through combined filtration and electrofiltration

Abstract

This study explores the efficacy of a ceramic membrane combining filtration, electrofiltration, and backwashing for oily water treatment. A secondary mullite membrane was synthesized, showcasing high permeate flux (534 LMH), biaxial flexural strength (75.21 MPa), and cost-effectiveness. Operational parameters, set at 2 bar pressure and 0.727 m s⁻¹ cross-flow velocity, were optimized for desirable permeate flux and oil removal rates. Critical electric field intensity (E_crit) ranged from 50 to 55 V, guiding optimal voltage selection for electrofiltration. Electrokinetic phenomena, such as electrophoresis and electroosmosis, addressed fouling issues. Higher salt concentrations exacerbated fouling and reduced electric field efficiency. Energy analysis revealed potential savings, dropping from 3.88 kW h m³ without voltage to 2.71 kW h m³ at 65 V for salt-free solutions. However, higher salt concentrations increased fouling, elevating energy consumption. These findings affirm the value of affordable ceramic membranes for oily water treatment, stressing the need for parameter optimization to enhance performance and energy efficiency.