Adsorption characteristics of Acidianus manzaensis YN25 on chalcopyrite: Surface thermodynamics and the extended DLVO theory

The adsorption of Acidianus manzaensis YN25 on chalcopyrite was investigated experimentally and theoretically. A. manzaensis showed high adhesion affinity to the chalcopyrite under acidic condition, but low adhesion affinity under neutral and alkaline conditions. The microbe-mineral adhesion was assessed by the surface thermodynamics and the extended DLVO theory. The experimental results were in agreement with the theory. Moreover, A. manzaensis grown on chalcopyrite, sulfur, and ferrous ion showed similar adsorption phenomena. The adsorptive capacity of A. manzaensis increased with increasing temperature and decreasing pH respectively, and within the range of investigation, the best adsorption was achieved at pH 2.0 and 65 degrees C. This study provided new insights for bio-catalytic oxidation of sulfide minerals by the thermophilic acidophilic archaea.