Some strains of Bacillus species of heavy metals on biyosorption

Adherence of the striking gases or the dissolved substances onto a solid or liquid surface is called adsorption. It is a method used widely to remove environmental pollution. However, cost is an important factor in adsorption and thus use of the low-cost local resources to process harmful wastes is necessary for development of environmental biotechnology.In the present study, Ni(II) ions were removed from the aqueous solution by using Bacillus subtilis bacteria, a low-cost and Bacillus sb. type microorganism and effect of the initial concentration, temperature, pH, adsorpbent dosage and time on adsorption was investigated.For this purpose, a certain amount of the adsorbent was mixed with a certain amount of solution the metal ion, initial concentration of which is specified, and reduction in the equilibrium concentration with the time was measured, and so the kinetic data were obtained and the equilibrium time was found. Adsorption rate constants were calculated by assessing these kinetic in pseudo-first and pseudo-second order rate models and activation energy was calculated by using these rate constants at various temperatures.A fixed amount of the adsorbent was shaken with a series of the solutions with different concentrations for equilibrium time and the equilibrium concentrations were established by analyzing the solutions after equilibrium time. Adsorption isotherms were obtained by plotting the amount of the metal ions adsorbed onto a unit amount of the adsorbent versus the equilibrium concentration. Adsorption isotherm constants were calculated by assessing the adsorption isotherm data in Freundlich and Langmuir isotherm models and again by the aid of these data, free energy change (?G), enthalpy change (?H) and entropy change (?S) were calculated.Furthermore, amounts of percent adsorption (A %) of Ni (II) ions as double and triple mixture were found and adsorption competition of these metal ions were investigated and effect of the adsorbent dosage on the amount of adsorption were studied as well.