title: Kinetics and thermodynamics of adsorption for Cd on green manufactured nano-particles.
abstract: Magnetic nano-particles CuFe(2)O(4) were successful manufactured from industrial sludge by combination of acid leaching, chemical exchange, and ferrite process. For the first time these recycled nano-particles were used as adsorbent to investigate the kinetics and thermodynamics for adsorption of Cd in aqueous solutions. These experimental results showed that Cd(2+) adsorption efficiency increased from 0.85 to 99.9% when pH increased from 2 to 6. The maximum adsorption capacity of Cd(2+) was found to be 17.54 mg g(-1) under the conditions at pH 6.0, contact time 30 min, and temperature 318 K. The pseudo-second-order kinetic model provides the best correlation with the experimental data compared to the pseudo-first-order model. The Langmuir model yields a better fitting than the Freundlich model for Cd(2+) adsorption on CuFe(2)O(4) nano-particles under investigated temperatures. The thermodynamic constants of the adsorption process were evaluated, ΔG°, ΔH° and ΔS° is -6.05 kJ mol(-1) (at 318 K), 0.71 kJ mol(-1), and 4.53 J mol(-1) K(-1), respectively. These results imply that Cd(2+) adsorption onto CuFe(2)O(4) is feasible, spontaneous and endothermic in nature.
authors.affiliation: Earth Dynamic System Research Center, National Cheng-Kung University, No. 1, University Road, Tainan City 701, Taiwan, ROC. todojen@gmail.com
authors.forename: Yao-Jen
authors.initials: YJ
authors.lastname: Tu
authors.forename: Chen-Feng
authors.initials: CF
authors.lastname: You
authors.forename: Chien-Kuei
authors.initials: CK
authors.lastname: Chang
mesh_terms: D000327:Adsorption; D002104:Cadmium / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D005296:Ferrous Compounds / Q000737:chemistry*; D007220:Industrial Waste; D007700:Kinetics; D060328:Magnetic Phenomena; D053768:Metal Nanoparticles / Q000737:chemistry*; D008956:Models, Chemical; D011078:Polychlorinated Biphenyls; D059027:Recycling; D013816:Thermodynamics; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: C523076:CuFe2O4; D005296:Ferrous Compounds; D007220:Industrial Waste; D014874:Water Pollutants, Chemical; D002104:Cadmium; D003300:Copper; D011078:Polychlorinated Biphenyls