Biosorption of Ag(I) from aqueous solution by Bacillus licheniformis strain R08

Biosorption of heavy metals is an effective technology for the treatment of industrial wastewater. In this paper, Bacillus licheniformis R08 was used as biosorbent for Ag+. The physic-chemical properties of biosorption of silver by Bacillus licheniformis R08 were studied. Experimental parameters, including pH, temperature, biosorption time, initial silver ion concentration and biomass concentration were optimized. Under the optimized conditions, the silver biosorption capacity and biosorption efficiency could reach 73.6mg.g(-1) and 73.6%, respectively. Equilibrium isotherms of biosorption by R08 were fitted by Langmuir equation and the theoretical maximum biosorption capacity was 136 mg.g(-1). FTIR results showed that-CO-NH and -COO- groups of R08 cell were confirmed to be the main active groups that could combine with silver ions.