Activated carbon derived from date pit and sodium alginate, application to the adsorption of methylene blue from aqueous solution: Equilibrium isotherms, kinetic study, and regeneration

Biocomposite beads (AC-SA) were prepared utilizing sodium alginate and activated carbon from a mix cultivar of date palm (Phoenix dactylifera) pits in order to study the removal of methylene blue (MB). Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and pH of zero point of charge (pH zpc ) investigations were used to evaluate the produced beads physiochemically. Numerous factors, such as adsorbent dosage, temperature, initial dye concentration, pH, and contact time, were taken into consideration while evaluating adsorption performance. The optimization method showed that, with a basic pH, 8.5 and 0.080 g bead weight, equilibrium was reached in 120 min. Several isotherms and kinetic models were used to evaluate the adsorbent capacity. The results showed that the greatest removal efficiency of MB onto AC-SA beads was 23.529 mg/g. Adsorption occurred via the pseudo-second order kinetic model and the coulombic forces adsorption mechanism. The Langmuir and Freundlich isotherms were determined to best suit the experimental data for the AC-SA beads. These findings demonstrate the potential of AC-SA biocomposites as economical and effective dye removal adsorbents.