title: Removal of lead(II) from aqueous solutions using carbonate hydroxyapatite extracted from eggshell waste.
abstract: Carbonate hydroxyapatite (CHAP) synthesized from eggshell waste was used for removing lead ion from aqueous solutions. The effects of pH, contact time and initial concentration were studied in batch experiments. The maximum uptake of lead ion was obtained at pH 6.0. Adsorption equilibrium was established by 60 min. The pseudo-first order, pseudo-second order and intraparticle diffusion kinetic models were applied to study the kinetics of the sorption processes. The pseudo-second order kinetic model provided the best correlation (R(2)>0.9991) of the used experimental data compared to the pseudo-first order and intraparticle diffusion kinetic models. The adsorption of lead ion by CHAP increased as the initial concentration of lead ion increased in the medium. The maximum lead ion adsorbed was found to be 101 mg g(-1). It was found that the adsorption of Pb(II) on CHAP was correlated well (R(2)=0.9995) with the Langmuir equation as compared to Freundlich isotherm equation under the concentration range studied. This study indicated that CHAP could be used as an efficient adsorbent for removal of lead ion from aqueous solution.
authors.affiliation: College of Marine Environment and Engineering, Shanghai Maritime University, 1550 Hai Gang Da Dao, Nanhui District, Shanghai 200135, PR China. zdldx@163.com
authors.forename: Dexiang
authors.initials: D
authors.lastname: Liao
authors.forename: Wei
authors.initials: W
authors.lastname: Zheng
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Li
authors.forename: Qi
authors.initials: Q
authors.lastname: Yang
authors.forename: Xiu
authors.initials: X
authors.lastname: Yue
authors.forename: Liang
authors.initials: L
authors.lastname: Guo
authors.forename: Guangming
authors.initials: G
authors.lastname: Zeng
mesh_terms: D000327:Adsorption; D002254:Carbonates; D017886:Durapatite / Q000737:chemistry*; D004531:Eggs; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D007700:Kinetics; D007854:Lead / Q000302:isolation & purification*; D012996:Solutions; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
chemical_list: D002254:Carbonates; D007220:Industrial Waste; D012996:Solutions; D014874:Water Pollutants, Chemical; D007854:Lead; D017886:Durapatite