Development of Graphene Oxide Membrane on Flat Mud Ceramic Support for Methylene Blue Dyes Removal

In this study, flat mud supports (Mud), sintered at different temperatures (900 °C–1050 °C), were prepared via dry uniaxial pressing process. The SEM analysis evidenced that the supports were free of defects and present homogeneous surface. The optimal treatment temperature was found at 950 °C, resulting in a low shrinkage of 9%, 32% of porosity, 1.4 µm of pore size, 20 MPa of mechanical strength, and water permeability of 168.21 L·h⁻¹·m⁻²·bar⁻¹. The low-cost support was coated with graphene oxide (GO) by dip coating method. The adhesion of GO powder on membrane surface was checked by SEM analysis demonstrating homogeneous coating layer over the Mud support. The GO/Mud membrane presents an average pore diameter of 0.63 µm and a water permeability of 69.08 L·h⁻¹·m⁻²·bar⁻¹. The membrane efficiency was explored for methylene blue (MB) removal, achieving high color retention of 96%. The study of the permeate flux decrease with time shows that membrane fouling follows the standard pore blocking model which was in accordance with the results obtained from the mass balance between inlet and outlet of the membrane during filtration, presenting an error less to 1%. After filtration operation, the initial membrane permeability was recovered by chemical regeneration using alternatively acidic–basic solution.