title: Biosorption of Pb (II) from aqueous solution by extracellular polymeric substances extracted from Klebsiella sp. J1: Adsorption behavior and mechanism assessment.
abstract: The adsorption performance and mechanism of extracellular polymeric substances (EPS) extracted from Klebsiella sp. J1 for soluble Pb (II) were investigated. The maximum biosorption capacity of EPS for Pb (II) was found to be 99.5 mg g(-1) at pH 6.0 and EPS concentration of 0.2 g/L. The data for adsorption process satisfactorily fitted to both Langmuir isotherm and pseudo-second order kinetic model. The mean free energy E and activation energy Ea were determined at 8.22- 8.98 kJ mol(-1) and 42.46 kJ mol(-1), respectively. The liquid-film diffusion step might be the rate-limiting step. The thermodynamic parameters (ΔG(o), ΔH(o) and ΔS(o)) revealed that the adsorption process was spontaneous and exothermic under natural conditions. The interactions between EPS system and Pb (II) ions were investigated by qualitative analysis methods (i.e Zeta potential, FT-IR and EDAX). Based on the strong experimental evidence from the mass balance of the related elements participating in the sorption process, an ion exchange process was identified quantitatively as the major mechanism responsible for Pb (II) adsorption by EPS. Molar equivalents of both K(+) and Mg(2+) could be exchanged with Pb(2+) molar equivalents in the process and the contribution rate of ion exchange to adsorption accounted for 85.72% (Δmequiv = -0.000541).
authors: School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, People's Republic of China.|State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, People's Republic of China.
authors: Wei
authors: W
authors: Wei
authors: Advanced Water Management Centre, The University of Queensland, St Lucia, Queensland 4072, Australia.
authors: Qilin
authors: Q
authors: Wang
authors: School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, People's Republic of China.|State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, People's Republic of China.
authors: Ang
authors: A
authors: Li
authors: School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, People's Republic of China.|State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, People's Republic of China.
authors: Jixian
authors: J
authors: Yang
authors: School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, People's Republic of China.|State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, People's Republic of China.
authors: Fang
authors: F
authors: Ma
authors: School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, People's Republic of China.|State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, People's Republic of China.
authors: Shanshan
authors: S
authors: Pi
authors: School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, People's Republic of China.|State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, People's Republic of China.
authors: Dan
authors: D
authors: Wu
mesh_terms: D000327:Adsorption; D045424:Complex Mixtures / Q000737:chemistry*; D007709:Klebsiella / Q000737:chemistry*; D007854:Lead / Q000737:chemistry*; D008956:Models, Chemical
chemical_list: D045424:Complex Mixtures; D007854:Lead