Abstract
The biosorption capability of royal poinciana pod-derived biosorbent was investigated for the removal of hexavalent chromium from synthetic wastewater. Scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy were used to examine the morphology and other properties of the biochar prepared by pyrolysis at 350 degrees C. Operational parameters such as pH, biochar dose, interaction time, and starting metal ion concentration were tuned. A maximum metal removal efficiency of 93% was achieved at pH 6.0. Optimization investigations for experiments have also been conducted using response surface methodology which included three parameters by applying Box-Behnken design with 10.48 of model F-value and 0.93 of R-2 value (coefficient of determination). The kinetic theories and isotherm models of Cr (VI) ion adsorption have also been established. Pseudo-second-order model foretells the kinetics with 0.97 R-2 value. The Temkin isotherm and Dubinin-Radushkevitch provided the best-fit isotherms to explain adsorption phenomenon. This study suggests that royal poinciana pod-derived biochar may be used as an efficient, low-cost, and eco-friendly wastewater treatment bioadsorbent.