Modelling and optimization of methylene blue adsorption from wastewater utilizing magnetic marble dust adsorbent: A response surface methodology approach

Abstract

The Marble Dust (MD), a by-product generated by the Marble industry, was modified by magnetic nanoparticles and denoted as M-MD, characterized by XRF, XRD, SEM, EDX, FT-IR, VSM, and B-E-T for surface area analysis. M-MD was employed as MB elimination sorption material from an aqueous solution for optimization purposes; response surface modelling was applied to study dye elimination. The independent variables effect, the adsorbent dose, pH, contact time, and starting amount (concentration) of Dye on the elimination process was evaluated, which were varied in the range of (200–1200 mg/L), (3–9), (10–90 min), and (10–50 mg/litre) respectively. The amount of solution had a considerable effect on the elimination rate of MB. The isotherm and adsorption kinetics analysis indicates that Langmuir, besides the pseudo-second-order model, is the pattern for dye sorption by marble dust. Adsorption is nonspontaneous and endothermic, According to the estimated thermodynamic parameters. Finally, Statistical significance was shown for the quadratic model, and the current work demonstrates that M-MD may be utilized as adsorbent material for adsorption of MB dye.