| Abstrakt: |
Lead is a potentially toxic metal which easily contaminates water forms due to it ubiquitous applications. The demonstration of viable techniques to remove Lead ions from water is one of the most researched topics. In this study, the highly reported surface and pore advantages exhibited by metalorganic frameworks is exploited for the trapping of aqueous Lead. The Zinc-based MOF5 was synthesized for adsorption tests involving the sequestration of Lead ions. Tests were conducted to determine the effects of concentration, contact time and pH in the uptake of Lead ions from solution. The extent of adsorption was evaluated as percentage uptake of Lead and Lead uptake capacity of MOF5. The results showed that while the percentage uptake and Lead uptake capacity of MOF5 depended on the concentration and pH of solution, contact time had only minimal effects. Five adsorption isotherms were applied to evaluate the adsorption data including Dubinin-Radushkevich, Freundlich, Langmuir, Elovich and Jovanovich. However, the R² values gave the Elovich isotherm (R² = 0.8029) as the best fitting model, implying the dominance of multilayer interaction between MOF5 and Lead ions. The pseudo-second-order kinetics and the Webber-Morris intraparticle diffusion were also applied to evaluate the kinetics of the process. The pseudo-second-order kinetic plots was observed to provide the better fit to the kinetics, ahead of the Webber-Morris intraparticle diffusion, depicting the dominance of chemisorption. The high percentage (> 90 %) of Lead ions taken up, and the high capacity of MOF5 for the ions, as observed across all three types of adsorption tests performed, demonstrates that MOF5 (> 45 mg/g)) could represent an efficient adsorbent for the targeted separation of Lead ions during water treatment. [ABSTRACT FROM AUTHOR] |
