Development and Characterization of Chitosan-TiO2-Based Photocatalytic Membrane for Water Treatment: Applications on Methylene Blue Elimination

Abstract

Photocatalytic membrane reactors (PMRs) are an innovative technology for water treatment, effectively combining membrane filtration and photocatalysis to enhance contaminant removal while enabling the regeneration of fouled membranes. In this study, a new porous film of chitosan that was impregnated with TiO2 was developed and coated onto a ceramic support by spin coating to form a new porous immobilized PMR. The formed membrane was tested for two reasons: the removal of methylene blue dye by a dead-end filtration process and to demonstrate its ability to self-regenerate under UV exposure. The selective layer of the membrane was characterized using FTIR spectroscopy, X-ray diffraction, scanning electron microscopy (SEM), and water permeability tests. The results confirmed the formation of an amorphous film with no chemical interaction between chitosan and TiO2. The membrane exhibited an average water permeability of 10.72 L/m2·h·bar, classifying it as either ultrafiltration (UF) or nanofiltration (NF). Dead-end filtration of methylene blue (10 mg L−1) achieved 99% dye removal based on UV–vis analysis of the permeate, while flux declined rapidly due to fouling. Subsequent UV irradiation removed the deposited dye layer and restored approximately 50% of the initial flux, indicating partial self-regeneration. Overall, spin-coated chitosan–TiO2 layers on ceramic supports provide high dye removal and photocatalytically assisted flux recovery, and further work should quantify photocatalytic degradation during regeneration.