Kinetic and Fixed Bed Studies for Copper Removal from Solutions by Walnut Tree Sawdust (Juglans regia Linnaeus)

Abstract

This study investigates the adsorption kinetics and removal conditions of copper by walnut tree sawdust from synthetic solutions in the batch and fixed bed reactors. The selected experimental parameters for the batch reactor were concentration, solution pH, adsorbent amount and temperature. The optimum batch reactor conditions were applied to the fixed bed reactor. The experimental parameters of the fixed bed reactor were flow rate, bed height, and concentration. The optimum removal conditions for copper removal in the batch reactor were determined as pH (5), temperature (25oC), concentration (25 mg/L), and adsorbent dosage (10 g/L). The kinetic data obtained from the batch reactor were analyzed by the pseudo-first-order and the pseudo-second-order kinetic models and the kinetic data were successfully correlated with the pseudo-second-order model. Activation energy of the process was calculated to be 15.79 kJ/mol. The optimum parameters for the fixed bed reactor were designated as 0.5 mL/min flow rate, 100 mg/L concentration and 15 cm bed height. The kinetic data obtained from the fixed bed reactor were analyzed with the Yoon-Nelson and Thomas kinetic models. The fixed bed kinetics could be described with the Thomas model. Maximum adsorption capacity was calculated as 6.24 mg/g in the fixed bed reactor.