Removal of Malathion by Sodium Alginate/Biosilicate/Magnetite Nanocomposite as a Novel Adsorbent: Kinetics, Isotherms, and Thermodynamic Study

Abstract

Background: Organophosphorus pesticides are one of the widely consumed poisons in agriculture. The consumption of drinking water, which contains an excessive amount of poison, therefore, contributes to adverse health and hygiene outcomes in humans. Methods: In this study, a new sodium alginate/biosilicate/magnetite (SABM) nanocomposite made by the precipitation method was used to remove Malathion from aqueous solutions. The properties of MBSA were analyzed using XRD, SEM, EDX, and FTIR techniques. The possible impact of several parameters such as contact time, pH, initial Malathion concentration, temperature, and MBSA dosage on the adsorption process were investigated. The equilibrium isotherm and kinetic models were employed to evaluate the fitness of the experimental data. Results: The highest removal (94.82%) of MBSA was obtained at an optimum pH of 7, the contact time of 120 minutes, the adsorbent dosage of 4 g/L, Malathion concentration of 10 mg/L, and temperature of 318°K. The adsorption process followed the Freundlich isotherm model (R2 = 0.999), which implied that the adsorption process of Malathion molecules onto MBSA might be mainly a multi-molecular layer. Conclusions: The results of this study showed that MBSA had a good removal efficiency, lower cost of processing, and as well as not producing substances harmful to the environment, which make it a promising adsorbent to remove Malathion from aqueous environments.