Zeitschrift für Membranwissenschaft und -technologie

Abstrakt

Adsorption of Heavy Metals Cations onto Zeolite Material from Aqueous Solution

Maria Visa and Nicoleta Popa

Increased urbanization and industrialization led to excessive release of wastes into the environment; one of them, causing many problems not only to the environment but also to human health, is fly ash resulted from coal combustion. One of the solutions for solving these problems would be fly ash reutilization as an adsorbent for wastewater treatment and for obtaining new and efficient materials such as zeolites. Class “F” fly ash collected from C.H.P. Craiova from Romania was used for obtaining new zeolite materials for advanced wastewater treatment. This material was characterized by AFM, XRD, FTIR, SEM to outline the crystalline and morphology modifications. Hydrothermal modified fly ash using NaOH was used for heavy metals removal (Cd2+, Cu2+ and Ni2+) from synthetic wastewaters containing one, two and three pollutants. For obtaining a maximum efficiency during the adsorption process the adsorption conditions (contact time, optimum amount of substrate) were optimized. These parameters were further used in thermodynamic and kinetic modeling of the adsorption processes. The uptake of Cd2+, Cu2+ and Ni2+ was followed by a Langmuir adsorption isotherm and the maximum uptake capacity was estimated to be 95.24 mg/g Cd2+, 107.52 mg/g Cu2+ from aqueous solution with two cations. Correlated with the surface structure, composition and morphology the adsorption kinetic mechanisms and the substrate capacities are further discussed.