Thermodynamics and Adsorption Efficiencies of Maize Cob and Sawdust for the Remediation of Toxic Metals from Wastewater

Muhammad B. Ibrahim

Department of Pure and Industrial Chemistry, Bayero University, Kano, Nigeria.

DOI: 10.4236/gep.2013.12004                

Abstract

The thermodynamics and sorption efficiencies for the remediation of Cr, Ni and Cd from their aqueous solutions using Maize Cob (MC) and Sawdust (SD) in a batch system are reported. Efficiencies were judged based on parameters such as sorbent weight, initial adsorbate loading concentration, pH and surface area. Shimadzu AA650 Double Beam Atomic Absorption/Flame spectrophotometer was employed to study concentration differences before and after the adsorption process. Parameters such as ΔH, ΔS and ΔG were determined. On MC, ΔH varied as 1466.59, 1271.21 and 1347.70kJmol^-1 for Cr, Ni and Cd respectively. While on SD it varied as -566.85, 256.32 and 888.77kJmol^-1respectively for the same order of metal ions. The three ions were found to be chemisorbed onto MC, while on SD Cr and Ni were physisorbed and Cd remains chemisorbed as suggested by Freundlich isotherm.

Keywords

Adsorbate; Adsorbent; Maize Cob; % Removal; Sawdust; Wastewater

Conflicts of Interest

The authors declare no conflicts of interest.

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