title: Modeling and mechanism of the adsorption of copper ion onto natural bamboo sawdust.
abstract: The sorption of copper ions onto natural bamboo sawdust with cellulose-lignin polymeric structure strongly depends on pH. The adsorption capacity for copper ions increases as increasing pH and copper loadings. The fitting of copper pH boundary curve by NEM surface complexation models shows that: three-sites model including the ion exchange reaction of permanent charge fits better than two-sites model. The incorporation of the hydrated ion reaction gives better fitting results. XAFS study shows that: copper ions mainly form inner complexation with sawdust, but there is no obvious evidence on the complexation of carboxylic acid groups with copper ions. EXAFS fitting result shows that: as pH rises, the spatial configuration of copper ions shifts from tetrahedron to octahedron. Meanwhile the increase in the coordination number indicates that hydrated copper ions participate in the adsorption. Both XANES and EXFAS spectrum offer a similar explanation for copper adsorption in the range of experimental and fitting errors.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, People's Republic of China; School of Environmental Science and Engineering, Suzhou University of Science and Technology, People's Republic of China.
authors.forename: Xue-Tao
authors.initials: XT
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, People's Republic of China.
authors.forename: Teng
authors.initials: T
authors.lastname: Zeng
authors.affiliation: School of Environmental Science and Engineering, Suzhou University of Science and Technology, People's Republic of China.
authors.forename: Xue-Yan
authors.initials: XY
authors.lastname: Li
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, People's Republic of China.
authors.forename: Zhang Jun
authors.initials: ZJ
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, People's Republic of China.
authors.forename: Hong-Wen
authors.initials: HW
authors.lastname: Gao
authors.affiliation: National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, People's Republic of China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Xie
mesh_terms: D000327:Adsorption; D031723:Bambusa; D002482:Cellulose / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007474:Ion Exchange; D008031:Lignin / Q000737:chemistry; D008962:Models, Theoretical; D014934:Wood; D056928:X-Ray Absorption Spectroscopy
chemical_list: D003300:Copper; D002482:Cellulose; D008031:Lignin