title: Removal of Ag+ from water environment using a novel magnetic thiourea-chitosan imprinted Ag+.
abstract: A novel, thiourea-chitosan coating on the surface of magnetite (Fe(3)O(4)) (Ag-TCM) was successfully synthesized using Ag(I) as imprinted ions for adsorption and removal of Ag(I) ions from aqueous solutions. The thermal stability, chemical structure and magnetic property of the Ag-TCM were characterized by the scanning electron microscope (SEM), Fourier transform infrared spectrometer (FT-IR) and vibrating sample magnetometer (VSM), respectively. Batch adsorption experiments were performed to evaluate the adsorption conditions, selectivity and reusability. The results showed that the maximum adsorption capacity was 4.93 mmol/g, observed at pH 5 and temperature 30°C. Equilibrium adsorption was achieved within 50 min. The kinetic data, obtained at the optimum pH 5, could be fitted with a pseudo-second order equation. Adsorption process could be well described by Langmuir adsorption isotherms and the maximum adsorption capacity calculated from Langmuir equation was 5.29 mmol/g. The selectivity coefficient of Ag(I) ions and other metal cations onto Ag-TCM indicated an overall preference for Ag(I) ions, which was much higher than non-imprinted thiourea-chitosan beads. Moreover, the sorbent was stable and easily recovered, the adsorption capacity was about 90% of the initial saturation adsorption capacity after being used five times.
authors: College of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
authors: Lulu
authors: L
authors: Fan
authors: Chuannan
authors: C
authors: Luo
authors: Zhen
authors: Z
authors: Lv
authors: Fuguang
authors: F
authors: Lu
authors: Huamin
authors: H
authors: Qiu
mesh_terms: D000327:Adsorption; D048271:Chitosan / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008280:Magnetics; D008855:Microscopy, Electron, Scanning; D012834:Silver / Q000302:isolation & purification*; D013696:Temperature; D014867:Water / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D014867:Water; D012834:Silver; D048271:Chitosan