title: Biosorption of Cd(II) by live and dead cells of Bacillus cereus RC-1 isolated from cadmium-contaminated soil.
abstract: The present study investigated the biosorption capacity of live and dead cells of Bacillus cereus RC-1 for Cd(II). The biosorption characteristics were investigated as a function of initial pH, contact time, and initial cadmium concentration. Equilibrium biosorption was modeled using Langmuir, Freundlich and Redlich-Peterson isotherm equations. It was found that the maximum biosorption capacities calculated from Langmuir isotherm were 31.95 mg/g and 24.01 mg/g for dead cells and live cells, respectively. The kinetics of the biosorption was better described by pseudo-second order kinetic model. Desorption efficiency of biosorbents was investigated at various pH values. These results indicated that dead cells have higher Cd(II) biosorption capacity than live cells. Furthermore, zeta potential, transmission electron microscopy (TEM), scanning electron microscopy (SEM) coupled with energy dispersive X-ray (EDX), and Fourier transform infrared spectroscopy (FTIR) studies were carried out to understand the differences in the Cd(II) biosorption behavior for the both biosorbents. The bioaccumulation of Cd(II) by B. cereus RC-1 was found to depend largely on extracellular biosorption rather than intracellular accumulation. Based on the above studies, dead biomass appears to be a more efficient biosorbent for the removal of Cd(II) from aqueous solution.
authors: School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China.
authors: Fei
authors: F
authors: Huang
authors: Zhi
authors: Z
authors: Dang
authors: Chu-Ling
authors: CL
authors: Guo
authors: Gui-Ning
authors: GN
authors: Lu
authors: Roy R
authors: RR
authors: Gu
authors: Hong-Juan
authors: HJ
authors: Liu
authors: Hui
authors: H
authors: Zhang
mesh_terms: D000327:Adsorption; D001409:Bacillus cereus / Q000166:cytology* / Q000302:isolation & purification* / Q000378:metabolism / Q000648:ultrastructure; D061249:Batch Cell Culture Techniques; D001673:Biodegradation, Environmental; D002104:Cadmium / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D007477:Ions; D007700:Kinetics; D050296:Microbial Viability; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000302:isolation & purification*; D013052:Spectrometry, X-Ray Emission; D017550:Spectroscopy, Fourier Transform Infrared; D055672:Static Electricity; D013696:Temperature; D013997:Time Factors
chemical_list: D007477:Ions; D012989:Soil Pollutants; D002104:Cadmium