The metal-tolerant bacterium strain BX

was isolated from polluted soils.The result of 16S rDNA sequence analysis indicated that the bacterium was Providencia alcalifaciens.The adaptability of bacterium BX to surroundings was discussed.The effects of the adsorption conditions

such as pH and temperature on the adsorption capacity by the bacterium BX from aqueous solutions were also investigated. Kinetic and isothermal study of BX toward Cu2+ was carried out.Immobilization was performed taking porous ceramics as carrier.The results showed that the bacterium BX could tolerant 7 mmol·L-1 of Cu2+ and 7.5% of NaCl

and its growth was observed at conditions of pH4.0—11.0 and 15—50℃.The bacterium BX removed 85.84% of Cu2+ after 240 min of incubation in a solution containing 100 mg·L-1 of Cu2+ at pH5.5

and the adsorption capacity of Cu2+ reached 128.74 mg·g-1(dry bacterium).Kinetic study showed that the pseudo-second-order kinetic model fitted well with the experimental data whereas intraparticle diffusion could not be ignored

suggesting a chemical reaction mechanism.This would indicate that the adsorption of Cu2+ is a complex mix of surface adsorption occurring in the boundary layer of the bacterial particle and intraparticle diffusion.The isotherm biosorption of BX toward Cu2+ was in accordance with the Freundlich model

suggesting that the adsorption process followed a monolayer sorption.After the formation of biofilm on the porous ceramics

the adsorption rate of BX on 50 mg·L-1 copper ion solution reached 92.53%.The experimental results demonstrated the potential application of the tested bacterium BX in the treatment of heavy metal wastewater for the strong adsorption under a wide range of environmental conditions.