Authors: M. A. O. BADMUS, T. O. K. AUDU, B. U. ANYATA
Abstract: Lead adsorption from industrial wastewater was studied with the aim of detoxifying industrial effluents before their safe disposal onto land or into river waters. Activated periwinkle shell carbon (PSC) was prepared and characterised for various physiochemical properties. To determine lead(II) removal capacity, the performance of PSC was compared with that of commercial activated carbon (CAC) and a mixture of PSC and CAC (PSC: CAC) in a ratio 1:1. The effect of various parameters such as adsorbent dose, contact time, pH, agitation speed, and particle size of the adsorbent was studied to optimise the conditions for maximum adsorption. Batch adsorption kinetic experiments revealed that the adsorption of Pb(II) onto PSC involved fast and slow processes. The mechanisms of the rate of adsorption were analysed using the Elovich equation and a pseudo-second-order model. It was found that the adsorption mechanisms in the lead/adsorbent system follow pseudo-second-order kinetics with a significant contribution from film diffusion. The adsorption isotherms were described by means of the Langmuir and Freundlich isotherms and both models represent the adsorption process. The percentage removal of lead onto PSC, PSC:CAC, and CAC was 82.78%, 92.68%, and 88.44%, respectively.
Keywords: Lead, Adsorption, Kinetics, Periwinkle shell, Wastewater
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