Morus alba- A Potential Sorbent for the Removal of Arsenic: Equilibrium, Kinetic and Thermodynamic Study

Abstract

In present study, arsenic (As) uptake potential of an eco-friendly Morus alba (mulberry) leave biomass was analyzed. Surface properties of the sorbent and its affinities for arsenic ions with respect to temperature were studied. Freundlich, D-R, Florry-Huggins and Halsey isotherms were found to be similar with recorded experimental data. Maximum sorption capacities 2.82 mg/g and 4.93 mg/g were calculated for As(III) and As(V) at pH-6 and pH-4, respectively. The energy values of the sorption 3.31-5.89 (<8) kJ/mole indicated the physisorption. The applicability of Halsey isotherm supported the heteroporosity of the biomass. Mechanism of the reaction was best explained by pseudo first order rate, Morris-Weber and Richenberg equations. Intra-particle diffusion as well as surface sorption was noticed during the study. Equilibrium was achieved up to 120 minutes. Thermodynamically, sorption reaction was endothermic and spontaneous in nature. Maximum recoveries of As(III) and As(V) were 83.3% and 95.52%, respectively observed with 1 M H₂SO₄