Kinetics, Equilibrium and Thermodynamic Studies on the Adsorptive Removal of Nickel, Cadmium ‎and Cobalt from Wastewater by Superparamagnetic Iron Oxide Nanoadsorbents

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Journal Title, Volume, Page: 
The Canadian Journal of Chemical Engineering Volume 90, Issue 5, pages 1231–1238
Year of Publication: 
Nashaat N. Nassar
Department of Chemical and Petroleum Engineering, University of Calgary, Calgary, Alberta, Canada, T2N 1N4
Current Affiliation: 
Department of Chemical Engineering, Faculty of Engineering and Information Technology, An-Najah National University, Nablus, Palestine
Preferred Abstract (Original): 

Because of its unique properties, such as specific functionality and large specific surface area, iron oxide nanoadsorbents had showed potential for energy and environmental applications. This work investigated the adsorptive removal of different metal ions from wastewater by superparamagnetic iron oxide nanoadsorbents (Fe3O4). Batch-adsorption technique was employed to assess the kinetic behaviour and adsorption equilibrium of cadmium, cobalt and nickel. Accordingly, the effect of the following variables on the adsorption reaction was tested, namely: solution pH, contact time and temperature. Metal ion adsorption was found to be highly pH dependent with a maximum uptake achieved around pH 5.5. Kinetic studies showed that adsorption was fast and equilibrium was achieved in less than 60 min. The external mass transfer kinetic model was applied to the experimental results and provided reasonable overall volumetric mass transfer coefficients. Adsorption isotherms were determined and appropriately described by the Freundlich and Langmuir models, with a better fit to the Freundlich model. The amount of metal ion adsorbed increased as the temperature increased, suggesting an endothermic adsorption process. The thermodynamics studies indicated that the adsorption process was spontaneous and endothermic in nature. © 2011 Canadian Society for Chemical Engineering