摘要
An efficient porous spherical polyethyleneimine-cellulose （PEI-cell） absorbent was synthesized and char- acterized. The main influencing factors and adsorption mechanism for two typical metal ions, Cr3＋ and Fe3＋, were investigated. The adsorption performance primarily depends on the initial concentration of metal ions, pH value and temperature, and the chelation action between N atoms of PEl-cell and metal ions plays an important role. Under dynamic adsorption conditions, the saturation adsorption of polyethyleneimine-cellulose is 83.98 mg.g-1 for Cr（Ⅲ） and 377.19 mg-g-1 for Fe（Ⅲ）, higher than report- ed data and that of unmodified cellulose. The adsorption can be well described with second-order kinetic equation and Freundlich adsorption model, and AH, AG and 5 of the adsorption are all negative. With 5% HCI as eluent, the elution ratio of Cr（Ill） and Fe（llI） achieved 99.88% and 97.74% at 313 K, respectively. After the porous PEI-cell was reused 6 times, it still presented satisfactory adsorption performance. Above results show the advantages such as easily-acquired raw material, high efficiency, stable recycling oerformance and biodegradability.
An efficient porous spherical polyethyleneimine-cellulose(PEI-cell) absorbent was synthesized and characterized. The main influencing factors and adsorption mechanism for two typical metal ions, Cr3+and Fe3+, were investigated. The adsorption performance primarily depends on the initial concentration of metal ions, pH value and temperature, and the chelation action between N atoms of PEI-cell and metal ions plays an important role. Under dynamic adsorption conditions, the saturation adsorption of polyethyleneimine-cellulose is 83.98 mg·g-1for Cr(III) and 377.19 mg·g-1for Fe(III), higher than reported data and that of unmodified cellulose. The adsorption can be well described with second-order kinetic equation and Freundlich adsorption model, and ΔH, ΔG and ΔS of the adsorption are all negative. With 5%HCl as eluent, the elution ratio of Cr(III) and Fe(III) achieved 99.88% and 97.74% at 313 K, respectively.After the porous PEI-cell was reused 6 times, it still presented satisfactory adsorption performance.Above results show the advantages such as easily-acquired raw material, high efficiency, stable recycling performance and biodegradability.
基金
Supported by the National Natural Science Foundation of China(81373284,81102344)
the Project of Education Department in Sichuan(14ZB0267)
the Bureau of Science and Technology of Mianyang City of China(10Y003-8)
