Effect of operating conditions on the Cu2+ removal from wastewater by cementation on a fixed bed of zinc cylinders

Abstract

This work investigates the effect of operating conditions on the rate of Cu2+ removal from synthetic waste of copper sulphate solution by cementation on a fixed bed of zinc cylinders under different conditions of solution flow rate, initial copper sulphate concentration, bed height, cylinder diameter and solution temperature. The values of the mass transfer coefficient was found to increase with increasing solution flow rate and temperature, while it decreased with increasing bed height, cylinders diameter and initial copper sulphate concentration. The value of the activation energy of the reaction ranged from 2.5 to 4.60 kCal/mol with lower and higher solution flow rates, respectively, which show that the reaction is diffusion controlled. The mass transfer correlation was deduced by dimensional analysis and was found to be in the form that: Sh = 2.1 Re0.867 Sc0.33 (d/h)−1.02. In addition, another correlation was deduced for the effect of entrance region by removing the calming section which was found to be in the form that: Sh = 2.30 Re0.870 Sc0.33 (d/h)−0.96. The obtained results can help in the design of a continuous flow reactor that may be used for the removal of heavy metals from wastewater.