title: Rapid removal of Pb(II) from aqueous solution by chitosan-g-poly(acrylic acid)/attapulgite/ sodium humate composite hydrogels.
abstract: A series of novel granular chitosan-g-poly(acrylic acid)/attapulgite/sodium humate (CTS-g-PAA/APT/SH) composite hydrogels were successfully prepared by one-step free radical graft polymerization and applied as adsorbents for the removal of Pb(II) from aqueous solution. The effects of adsorbent composition (including the contents of APT, SH and CTS) on adsorption capacity and adsorption rate were investigated in detail. Results from kinetic experiments showed that the rate of Pb(II) adsorption on the composite hydrogels was quite fast, that more than 90% of the equilibrium adsorption capacity occurs within two minutes and that the adsorption equilibrium could be achieved within 10 minutes. The adsorption kinetics fit well with the pseudo-second order equation. The introduced SH is helpful for both adsorption capacity and adsorption rate. The -COOH and -COO of PAA, -NH2 of CTS, Ph-O and -COO- of SH, as well as cation exchange and Si-OH of APT, participate in adsorption of Pb(II). The synergistic effect of these groups is responsible for the high adsorption capacity and rate.
authors.affiliation: Key Laboratory for Attapulgite Science and Applied Technology of Jiangsu Province, Huaiyin Institute of Technology, Huaian, People's Republic of China.
authors.forename: Junping
authors.initials: J
authors.lastname: Zhang
authors.forename: Yeling
authors.initials: Y
authors.lastname: Jin
authors.forename: Aiqin
authors.initials: A
authors.lastname: Wang
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000327:Adsorption; D002413:Cations, Divalent / Q000737:chemistry; D048271:Chitosan / Q000737:chemistry*; D006812:Humic Substances; D020100:Hydrogels / Q000138:chemical synthesis* / Q000737:chemistry; D007700:Kinetics; D007854:Lead / Q000737:chemistry*; D017616:Magnesium Compounds / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D017655:Silicon Compounds / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D000180:Acrylic Resins; D002413:Cations, Divalent; D006812:Humic Substances; D020100:Hydrogels; D017616:Magnesium Compounds; D017655:Silicon Compounds; D014874:Water Pollutants, Chemical; C065246:chitosan-poly(acrylic acid); D007854:Lead; D048271:Chitosan; C026325:attapulgite