Synthesis of novel biochar from waste plant litter biomass for the removal of Arsenic (III and V) from aqueous solution: A mechanism characterization, kinetics and thermodynamics

Abstract

The present study is focusing on utilization of a new feedstock material for the preparation of biochar. The dry waste leaves litter of Tectona and Lagerstroemia speciosa was used for synthesizing the biochar at 800 °C for 1 h in muffle furnace represents as TB 800 and LB 800 and then used for the removal of As(III) and As(V) from aqueous solution. The prepared biochar materials had a crystalline structure and was characterized by using Scanning electron microscopy (SEM), Energy dispersive X-ray (EDX), Brunaur emmit teller (BET), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Zeta potential, particle size and X-ray photoelectron spectroscopy (XPS). In regeneration study it was observed that prepared biochar material could be used up to four times with good removal percentage of Arsenic (III and V). The experimental data fitted well by Langmuir model for As(V) removal using TB 800 and LB 800, Freundlich model for As(III) removal by LB 800 and Temkin model for As(III) removal by TB 800. Pseudo-second-order kinetics was followed and best fitted with the obtained data of As(III) and (V) removal. Thermodynamics study revealed that the process of adsorption was endothermic for the removal of As(III) and exothermic for the adsorption of As(V) using TB 800 and LB 800. The adsorption capacity obtained for the removal of As(III) was 666.7 μg/g and 454.54 μg/g for TB 800 and LB 800, respectively and adsorption capacity for As(V) was 1250 μg/g for TB 800 and 714.28 μg/g was attained by LB 800.