Adsorption of gold from aqueous systems using microbial thermophilic proteins

A precious metal such as gold can be obtained from mining. Metals low concentrations at geothermal sites or in industrial waste are difficult to gausing the conventional mining process. Alternative approaches for recoverinmetals from dilute solutions have been developed, such as biosorption, i.adsorption using microorganisms or their derivatives. In this study, gold in aaqueous system was recovered via biosorption using proteins produced from aisolated thermophilic bacterial strain. Modified Thermus enhanced medium wused as the medium to improve protein production from the thermophilbacterial strain. The microbial proteins showed effective conditions for Au³⁺ ioadsorption. The optimum adsorption conditions for Au ions occurred at pH with an adsorption capacity of 482.0 mg/g protein. The metal ion adsorptiocapacity increased with increasing temperature. The adsorption isotherm wconducted at room temperature, because the Au ions could be well fitted by thFreundlich isotherm equation with q_max at 527.229 mg/g protein.