Biosorption of As(III) and As(V) on the surface of TW/MnFe2O4 composite from wastewater: kinetics, mechanistic and thermodynamics

In the present study, TW/MnFe2O4 composite (MTW) was synthesized and estimated as an effective biosorbent for removing As (III) and As(V) from wastewater. Physicochemical analysis of composite was performed through SEM–EDX. 86.615 and 83.478% removal efficiency were obtained by composite dosage of 2 g/L at contact time 120 min at temperature 30 °C and pH 7.0 and 4.0 for As(III) and As(V), respectively. Kinetic results study showed that Brouers–Weron–Sotolongo and Ritchie second-order for As(III) and Brouers–Weron–Sotolongo model for As(V) were capable to describe an accurate explanation of adsorption kinetic. Applicability of mechanistic models in the current study exposed that the rate-controlling step in the biosorption of both As(III) and As(V) on the surface of composite was film diffusion rather than intraparticle diffusion. The estimated thermodynamic parameters ΔG 0, ΔH 0 and ΔS 0 revealed that the biosorption of both As(III) and As(V) on the composite was feasible, spontaneous and exothermic.