title: Sorption of copper(II) onto super-adsorbent of bentonite-polyacrylamide composites.
abstract: In this work, bentonite embedded in the polyacrylamide (PAAm) gels was used as a novel adsorbent for the removal of Cu(II) from aqueous solution. The sorption and desorption of Cu(II) on bentonite-polyacrylamide (BENT-PAAm) was investigated as the function of pH, ionic strength, adsorbent content, Cu(II) concentrations and temperature. The results indicated that the sorption of Cu(II) on BENT-PAAm was strongly dependent on pH, ionic strength and temperature. The sorption increased from about 9% to 97% at pH ranging from 2.4 to 7. The sorption of Cu(II) on BENT-PAAm increased with increasing temperature and decreasing ionic strength. The sorption of Cu(II) on BENT and on BENT-PAAm was an endothermic and irreversible process. The results of desorption indicated that the adsorbed Cu(II) ions on solid particles were difficult to be desorbed from solid to liquid phase. From the comparison with BENT, BENT-PAAm showed higher sorption capacity with C(smax) increasing from 29 to 33 mg/g at pH 6.2 and from 11 to 20mg/g at pH 5.0 for the sorption of Cu(II) from BENT to BENT-PAAm composites. The average standard enthalpy change (Delta H degrees) and the entropy change (DeltaS degrees ) of Cu(II) sorption on BENT-PAAm are higher than those of Cu(II) sorption on BENT. The BENT-PAAm composites can be used as a super-adsorbent for the removal of Cu(II) from aqueous solution.
authors.affiliation: School of Nuclear Science and Engineering, North China Electric Power University, Beijing, 102206, PR China.
authors.forename: Guixia
authors.initials: G
authors.lastname: Zhao
authors.forename: Hongxia
authors.initials: H
authors.lastname: Zhang
authors.forename: Qiaohui
authors.initials: Q
authors.lastname: Fan
authors.forename: Xuemei
authors.initials: X
authors.lastname: Ren
authors.forename: Jiaxing
authors.initials: J
authors.lastname: Li
authors.forename: Yixue
authors.initials: Y
authors.lastname: Chen
authors.forename: Xiangke
authors.initials: X
authors.lastname: Wang
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000327:Adsorption; D000465:Algorithms; D001546:Bentonite / Q000737:chemistry*; D003188:Composite Resins; D003300:Copper / Q000737:chemistry* / Q000302:isolation & purification; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013696:Temperature; D013816:Thermodynamics; D014961:X-Ray Diffraction; D000099166:Polyacrylamides
chemical_list: D000180:Acrylic Resins; D001546:Bentonite; D003188:Composite Resins; D003300:Copper; D000099166:Polyacrylamides