Sustainable valorization of food waste into a pore-forming agent for ceramic membrane production: Experimental and DFT studies on methylene blue dye removal

Abstract

The increasing generation of food waste worldwide necessitates innovative solutions to limit environmental impact and optimize resource use. This research explores the potential of using food waste as a pore-forming agent into the main material, which is red clay to produce porous ceramic membranes as a sustainable approach. This membrane was investigated to see how effective it was at eliminating methylene blue (MB), a typical organic cationic dye, from industrial wastewater. The ceramic membranes were analyzed using various techniques, XRD, FT-IR, TGA, AFM, and a universal testing machine. The morphologies of the membranes were observed using SEM and elemental mapping. The optimized membrane containing 10 wt% of FW has a surface roughness of 162.5 nm, water permeability of 160 L h⁻¹ m⁻² bar⁻¹, and could reject 79 % for MB. The membrane had a negative surface charge at the pH >5.37, while the pH of MB was 6.17, implying adsorption as the removal mechanism for the cationic dye, this has been confirmed by DFT calculations. The dye removal for 20 mg L⁻¹ feed concentration was 79 % which increased to 86.1 % at pH = 10 and decreased to 74.26 % at the pH = 2. The total fabrication cost of this membranes is approximately 52.38 USD/m², which is cheaper than the conventional membranes. The affordability of these ceramic membranes is attributed to the use of economical materials that don't need high sintering temperatures. The results of this research demonstrate that these membranes are both cost-effective and have favorable characteristics that make them suitable for water treatment purposes.