Kinetics and Equilibrium Studies on Adsorption of Cobalt(II) and Manganese(II) Ions from Chloride Solutions Using Iminodiacetic Acid Chelating Resins
| Autor: | Cheng-Sheng Chang, 張正生 |
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| Rok vydání: | 2015 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 103 Ion exchange has a great potential to remove heavy metals from industrial wastewaters or heavy metal-containing sludge. In order to design and operate heavy metal removal process, the equilibrium relationship between ions and resins must be known a prior. A series of ion-exchange equilibrium tests of Co2+ and Mn2+ using Purolite S-930 plus were performed to studied the effect of initial metal concentrations, resin amount and operating temperature on the adsorption process. The equilibrium data were analyzedby the Langmuir isotherm, Freundlich isotherm, BET isotherm, Temkin isotherm and Dubinin-Radushkevich isotherm. For Co2+ and Mn2+, the Gibbs free energy change are -5541~-10943 J/mol and -3069~-4314 J/mol, enthalpy change are 20047~61440 J/mol and 27074~57781 J/mol, and entropy change are 84~245 J/molK and 97~214 J/molK, respectively. Experimental results show that the adsorption mechanism were best descripted by Freundlich isotherm and the equilibrium sorption capacities were increased by increasing operating temperature and initial metal concentrations but decreased with increasing resin amount. The ion-exchange kinetic data were regressed by the pseudo first-order kinetics model, pseudo-second-order kinetics model and intraparticle diffusion model and studied the effect of initial metal concentrations and resin amount on adsorption kinetics. By calculating the kinetic rate constant (k1、k2、 ) and adsorption capacity (qe) found that the ion exchange of Co2+ and Mn2+ on Purolite S-930 plus followed pseudo second-order kinetics and it reached a steady state value at 80 min for both Co2+ and Mn2+. By using Arrhenius equation, the activation energy are 2520~7702 J/mol and 4189~13312 J/mol for Co2+ and Mn2+, respectively. It means that the adsorption phenomenon matches ion exchange and chemisorption. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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