Comparative Study of Bivalent Cationic Metals Adsorption Pb(II), Cd(II), Ni(II) and Cu(II) on Olive Stones Chemically Activated Carbon

Thouraya Bohli

doi:10.4172/2157-7048.1000158

Abstract

In this work the ability of olive stone activated carbon (COSAC) to remove Pb(II), Cd(II), Ni(II) and Cu(II) metal ions from aqueous solutions was evaluated. The effect of initial pH, contact time and initial concentration on metal ions adsorption was investigated. The results indicated that pH 5 is the optimum value for metal removal. Adsorption kinetic rates were found to be fast; total equilibrium was achieved after 4 hours. Kinetic experimental data fitted very well the pseudo-second order equation and the values of adsorption rate constants were calculated. The equilibrium isotherms were evaluated in terms of maximum adsorption capacity and adsorption affinity by the application of Langmuir and Freundlich equations. Results indicate that the Langmuir model fits adsorption isotherm data better than the Freundlich model. The removal efficiency of heavy metal ions by COSAC decreases in the order Pb(II) >Cd(II) > Ni(II) ≥ Cu(II).

Highlights

Environmental pollution by heavy metals has become one of the most hazard problems due to their dangerous effect on aquatic flora and fauna even in relatively low concentrations
When comparing the results showed in table 5, we can conclude that adsorption of heavy metal ions depends on the adsorbent and its preparation by different oxidation agents that influence the surface area, pores distributions, and gives the acidic or basic characteristics of the functions groups formed on the surface of adsorbent
The removal of heavy ionic metals from aqueous solution by adsorption on olive stone activated carbon produced by thermo chemical process using phosphoric acid (COSAC) was investigated

Summary

Introduction

Environmental pollution by heavy metals has become one of the most hazard problems due to their dangerous effect on aquatic flora and fauna even in relatively low concentrations. Several heavy metal ions such as copper, nickel, cadmium and lead have been included in the U.S Environmental Protection Agency’s list of priority pollutants [1]. Hypertension and diabetes [3], and Lead is highly hepatotoxic [4] Many industrial processes, such as smelting, metal plating, mining pigments, cadmium-nickel-batteries, brass manufacture and discharge aqueous effluents containing high levels of these heavy metal ions. Adsorption on activated carbon is considered one of the most widely applied techniques for pollutants removal from contaminated media owing to its efficiency especially at low concentrations and process simplicity. In other side one must consider the sorbent characteristics as (i) the point of zero charge of the sorbent surface (pHpzc); (ii) sorbent specific surface area and porosity; (iii) sorbent surface functional groups Some of these adsorbent properties are related to the activation process and oxidation agent

Objectives

Results

Conclusion