Biological Removal of Nickel by Virgibacillus Isolated from Spring Badab Surt and Optimization and Adsorption Parameters

The basis of this research is based on sampling of different parts of Badab Surt Sari spring, including water, soil and sludge. The effect of parameters such as pH, contact time, amount of bacterial biomass and initial concentration of nickel metal ion on the sorption rate was investigated. The final equilibrium time in this experiment was eight hours, but in the first half hour the maximum absorption was made and the number eight is related to the optimal pH. The ion removal isotherm follows the Langmuir model equation and the maximum adsorption capacity of the metal ion was 0.51 mmol/g, Langmuir constant is 49.01, R2 was about 0.994. The use of bacterial biomass without and with metal by means of FT-IR showed that the groups involved, including carboxyl, hydroxyl and the amine. The results indicate that this isolate of rod-shaped bacterium, medium gram-positive filament, containing catalase, methyl red positive, has no motility and belongs to the genus Virgibacillus based on 16 S rDNA gene analysis. The adsorption capacity of nickel metal is very significant in the initial minutes and therefore, the use of the studied bacteria is appropriate in industry and biotechnological processes. The ions studied were adsorbed in the early stages when they were inactive, then in the secondary stage they were actively adsorbed slowly. Therefore, this bacterium has the ability to absorb metal in both live and dead forms.