Biosorption of Nickel (II) from Aqueous Solution Using Waste Tea ( Camella cinencis ) Materials

Biosorption is potentially an attractive technology for treatment of waste water for retaining heavy metals from dilute solutions. Several research in environmental biotechnology have shown that many biosorbents present in our environment have the capacity to remove heavy metals from solutions. This paper presents the result of studies carried out on sorption of nickel ions from aqueous solutions by waste tea ( Camellia cinencis ) powder as a low cost sorbent. The biosorption experiment were performed under various conditions such as different initial metal concentrations, pH and reaction time. It was found that, different concentration of nickel solution reached equilibrium at different times. About 0.2g of waste tea powder was found to be enough to remove 98% of 10g/L nickel ion concentration from 30ml metal solution. The optimum pH was found to be 5. The pseudo first order, pseudo second order, Elovich, intraparticle diffusion and parabolic diffusion models were used to describe the kinetic data. The data were best fitted with pseudo second order kinetic model for nickel. The experimental adsorption also reasonably fitted well the Langmuir and Freundlich isotherm.