Removal of cationic dye using polyvinyl alcohol membrane functionalized by D-glucose and agar

The composite membranes of polyvinyl alcohol (PVA) functionalized by d-glucose and agar using the solution casting method were prepared for dye wastewater treatment. The composite membranes improved their hydrophobicity and thermal stability with respect to the parent PVA. The membranes possess good mechanical behaviors and have suitable pore sizes and pHpzc for the adsorption of cationic dyes as well as were sustainable in aqueous solution for more than 350 min. In which, the 6P2D2A membrane containing 60 % PVA, 20 % D-glucose and 20 % agar can adsorb cationic dye (methylene blue) at the maximum adsorption capacity of 29 mg/g for 120 min, whereas negligible adsorption for anionic dye such as Congo red. The high and selective adsorption capacity of the composite membranes makes them promising candidates for further filtration and separation of dye molecules. Also, the adsorption data well fitted with the nonlinear pseudo-first-order kinetic and Langmuir isotherm model.