Removal of methylene blue dye from aqueous solution using pure talc and polyacrylamide–talc composite: Isotherms, kinetic and thermodynamic studies

Abstract

In this study, the composite of talc (as a natural mineral) and polyacrylamide (an inert polymer) was synthesized and the adsorption properties of the new material were examined for methylene blue (MB) in an aquatic medium. Experimental variables such as temperature, pH, and concentrations were optimized in detail. Adsorbents performance of the talc and PAA-talc composite for MB dye molecules were optimized: 40 mg L−1 at pH: 5.2 at 25 °C. The monolayer adsorption capacities for talc and PAA-talc were found to be 0.0124 mol kg−1 and 0.0104 mol kg−1 from the Langmuir isotherm model, respectively. Although talc has good adsorption properties, talc has the undesirable property of dissolving in water. This negative feature was eliminated by forming a water-insoluble composite with adsorption properties with PAA-talc. The adsorption kinetics of talc and PAA-talc indicated that the adsorption process in both materials fit both the PSO kinetic model and the IPD model. The adsorption thermodynamic of talc and PAA-talc indicated that the dye adsorption was both spontaneous and endothermic. The results of this study, when evaluated as a whole, showed that the PAA-talc composite is a potential adsorbent for methylene blue adsorption, which is simple to use, low cost, and efficient.