Comparative Study of Kinetics and Isotherms of Biosorption of Nickel by Bacteria and, Red and Brown Algae

Biological uptake of heavy metals is a very effective process for removing these pollutants from aqueous solutions is considered.Algae cell wall composition of cellulose and other materials such as agar, alginate and the metal ions play a key role in biosorption. Algae are of particular importance due to their low cost. Mechanisms are involved in the uptake of metals by bacteria is very complex and depends on physicochemical reactions of metal ions in solution, and so are the locations of cellular uptake. Microorganisms and algae contribute to the cycle of inorganic substances in nature.In this study the biological uptake of nickel by red algae Gracilaria, brown algae Cystoseira, Fucus and Gram-positive bacteria Bacillus, was studied.Parameters such as metal concentrations, pH, amount of algae, kinetic, and isotherms were studied in this experiment. The maximum rates of metal uptake by algae Gracilaria, Cystoseira and Bacillus at pH=6 and Fucus on the pH is about 5. The maximum nickel sorption was attained about for Fucus, Gracilaria, Cystoseira, and Bacillus, 0.94, 0.68, 0.34 and 0.65 mg/L respectively. This study has shown nickel (II) uptakes, equilibrium time of about 400,350,300 and 120 minutes for, Gracilaria, Cystoseira, Fucus and Bacillus, respectively, and the adsorption equilibrium date was well described by Langmuir equation.