Biosorption of Mercury onto Protonated Pistachio Hull Wastes – Effect of Variables and Kinetic Experiments

Abstract

 Abstract—Batch parametric experiments were performed to study the applicability of protonated pistachio hull waste as a sorbent with respect to the effect of pH of the solution, initial metal concentration, sorbent dosage and temperature on the metal removal efficiency. Optimum conditions for mercury removal were found to be pH 7.0 and adsorbent dose - 1.0 g/L.The metal uptake increased with increase in the initial concentration of the metal. The sorption process was identified as endothermic in nature favouring use of high temperature. The kinetic studies revealed that pseudo-second order model fitted well and the constants were determined. The pseudo-second order rate constant and maximum uptake capacity were found as 1.99 × 10 -3 g mg -1 min -1 and 48.78 mg g -1 with 50 mg L -1 metal concentration. Thermodynamic studies were conducted and the activation energy for the adsorption of mercury onto was found to be 10.26 KJ/ mol.