ADSORPTION OF ARSENATE IN WATER BY MAGNETIC ZnFe2O4/α-Fe2O3/BIOCHAR NANOCOMPOSITES: ISOTHERM AND KINETIC STUDIES

Abstract

The adsorption of arsenate into the water by magnetic ZnFe₂O₄/α-Fe₂O₃/biochar nanocomposite (MBC) were investigated in this article. Batch mode adsorption studies were carried out by varying pH, shaking temperature, and initial As⁵⁺ concentration. The adsorption of As⁵⁺ was pH dependent and showed maximum removal efficiency of As⁵⁺ at pH 8.0. Adsorption studies of 5–35 mg/L initial As⁵⁺ concentration were carried out at pH 8.0 and temperature of 303 K, 313 K, and 323 K. Langmuir and Freundlich, Temkin isotherm adsorption models were used to analyze the experimental data. The kinetic adsorption was studied using pseudo-first-order, pseudo-second-order, and Elovich models. The pseudo-second-order and Langmuir models fitted the adsorption of As⁵⁺ onto MBC. The adsorption of arsenate onto MBC was mainly controlled by the chemisorption and physisorption adsorption mechanisms. MBC could be easily recovered and reused using an external magnetic field. MBC had the potential to be high adsorption efficiency.