title: Removal of cephalexin from aqueous solutions by original and Cu(II)/Fe(III) impregnated activated carbons developed from lotus stalks Kinetics and equilibrium studies.
abstract: Lotus stalk activated carbon (AC) was produced by ultrasound digestion of lotus stalks in H(3)PO(4). Copper nitrate and iron nitrate were used to impregnate AC, producing Cu(II)-impregnated AC (AC-Cu) and Fe(III)-impregnated AC (AC-Fe). The modified ACs were characterized by N(2) adsorption-desorption isotherms, Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The adsorption kinetics and isotherms of cephalexin (CEX) in aqueous solution were studied for AC, AC-Cu and AC-Fe. The kinetics and equilibrium data agreed well with the pseudo-second-order kinetics model and Freundlich isotherm model for all three adsorbents. The results also showed that the adsorption capacities of AC-Cu and AC-Fe were larger than the capacity of AC and AC-Fe was found to be the most effective at the removal of CEX in solution. Furthermore, batch experiments were conducted to study the effects of pH (2.5-10.5), initial concentration of CEX (4-16 mg/L), ionic strength (10-1000 mM) on CEX removal.
authors.affiliation: School of architecture and environment, Sichuan University, Chengdu 610207, China.
authors.forename: Hai
authors.initials: H
authors.lastname: Liu
authors.forename: Weifeng
authors.initials: W
authors.lastname: Liu
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.forename: Chenglu
authors.initials: C
authors.lastname: Zhang
authors.forename: Liang
authors.initials: L
authors.lastname: Ren
authors.forename: Ye
authors.initials: Y
authors.lastname: Li
mesh_terms: D000327:Adsorption; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification*; D002244:Carbon / Q000737:chemistry*; D002506:Cephalexin / Q000737:chemistry / Q000302:isolation & purification*; D003300:Copper / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D014867:Water; D014961:X-Ray Diffraction
chemical_list: D000900:Anti-Bacterial Agents; D005290:Ferric Compounds; D012996:Solutions; D014867:Water; D002244:Carbon; D003300:Copper; D002506:Cephalexin