Kinetic Modeling for Removal of Pb, Cd, Ni, and Cr Ions from Petrochemical Effluent using Termite Soil

Increase in concentration of heavy metals ions in our water bodies is of great concern. This work is aimed at providing an environmental and cost effective adsorbent for the removal of Pb, Ni, Cr and Cd from petrochemical effluent. Termite soil was pretreated and used for the sorption process and process parameters such as contact time and particle size of the adsorbent was varied. Optimum contact time of 60 minutes was obtained for Pb and Cd ions while 40 minutes was obtained for Ni and Cr ions for all particle sizes of adsorbent used. Initial reaction rate H(mg/g.min) was of the order for the different particle sized adsorbent, 75mm: Pb>Cd>Cr>Ni, 212mm: Cd>Pb>Cr>Ni and 300mm: Cd>Pb>Ni>Cr. Pseudo first order kinetics had less difference between experimental and theoretical adsorption capacity (Qa - Qb) with R2 close to that obtained for Pseudo-second order kinetics. Hence it is considered as the kinetic order for the adsorption process. Percentage of the studied ions removed from the wastewater solution shows the suitability of the adsorbent sequestering of heavy metal ions from industrial wastewater.