Abstract
Biochars have attracted much research attention recently because of their potential applications in many environmental areas. In this study, rice straw-derived biochars produced at different pyrolysis temperatures (550-750 degrees C) were used as adsorbents for the removal of strontium (II) under different experimental conditions of time, pH, and temperature. Sr(II) sorption equilibrium occurs after 30min and its sorption maximum achieved at pH 6. The kinetic data obtained were analyzed to predict the constant rate of sorption using three common kinetic models: pseudo-first-order, pseudo-second-order equation, and intraparticle diffusion equation. The pseudo-second-order model was suitable for describing the sorption kinetics for the removal of Sr(II) from aqueous solution onto straw-derived biochar. Sorption of Sr(II) onto biochar was endothermic. Biochar has the highest Sr(II) sorption capacity in comparison to other adsorbents.