Batch and Fixed-Bed Column Adsorption of Cu(II), Pb(II) and Cd(II) from Aqueous Solution onto Functionalised SBA-15 Mesoporous Silica Afsaneh Shahbazi, 1 Habibollah Younesi 1 * and Alireza Badiei 2 1. Faculty of Natural Resources, Department of Environmental Science, Tarbiat Modares University, P.O. Box 46414-356, Noor, Iran 2. School of Chemistry, College of Science, University of Tehran, P.O. Box 14155-6455, Tehran, Iran Functionalised SBA-15 mesoporous silica with polyamidoamine groups (PAMAM-SBA-15) was successfully prepared with the structure characterised by X-ray diffraction, nitrogen adsorption–desorption, Fourier transform infrared spectra and thermogravimetric analysis. PAMAM-SBA-15 was applied as adsorbent for Cu(II), Pb(II) and Cd(II) ions removal from aqueous solution. The effects of the solution pH, adsorbent dosage and metal ion concentration were studied under the batch mode. The Langmuir model was fitted favourably to the experimental data. The maximum sorptive capacities were determined to be 1.74 mmol g −1 for Cu(II), 1.16 mmol g −1 for Pb(II) and 0.97 mmol g −1 for Cd(II). The overall sorption process was fast and its kinetics was fitted well to a pseudo-first-order kinetic model. The mean free energy of sorption, calculated from the Dubinin–Radushkevich isotherm, indicated that the sorption of lead and copper, with E > 16 kJ mol −1 , followed the sorption mechanism by particle diffusion. The adsorbent could be regenerated three times without significant varying its sorption capacity. A series of column tests were performed to determine the breakthrough curves with varying bed heights and flow rates. The breakthrough data gave a good fit to the Thomas model. Maximum sorption capacity of 1.6, 1.3 and 1.0 mmol g −1 were found for Cu(II), Pb(II) and Cd(II), respectively, at flow rate of 0.4 mL min −1 and bed height of 8 cm, which corresponds to 83%, 75% and 73% of metallic ion removal, respectively, which very close to the value determined in the batch process. Bed depth service time model could describe the breakthrough data from the column experiments properly. Keywords: removal, heavy metal, SBA-15, batch adsorption, fixed-bed column INTRODUCTION H eavy metals are found in wastewaters originating from chemical manufacturing, painting, mining, extractive metallurgy, nuclear and other industries (Sayari et al., 2004; Amini et al., 2009a). The occurrence in industrial effluents of increasing quantity of heavy metals that are non-biodegradable, bio-accumulative and toxic substances (Mureseanu et al., 2008; Amini and Younesi, 2009) requires removal processes that are efficient. The adsorption technique is particularly popular for wastewater treatment due to its efficiency, simplicity and rea- sonable cost (Amini et al., 2009b), a technique made possible by the use of mesoscopically ordered nanoporous silica mate- rials. The hybrid materials have important applications also in a wide variety of other fields such as separation, catalysis, due to the combination of their high surface area, high ion binding sites, good thermal and mechanical stabilities, resistance against swelling, well-ordered periodic nanoporous structure and control- lable pore diameter (Badiei and Bonneviot, 1998; Jiang et al., 2007; Mureseanu et al., 2008). Compared to analogous materials, SBA-15 is one of the most promising adsorbents due to its large pore diameter, thick silica pore walls and existing complemen- tary micropores within the silica walls which provide fast mass transfer rates (Mureseanu et al., 2008; Aguado et al., 2009). Vari- ous organic ligands containing donor atoms (such as nitrogen or sulphur) could be covalently anchored onto the mesoporous silica surface by functionalisation of the silanol groups. The obtained organic/inorganic hybrid materials are promising adsorbents for ∗ Author to whom correspondence may be addressed. E-mail addresses: hunesi@modares.ac.ir,hunesi@yahoo.com Can. J. Chem. Eng. 9999:1–12, 2012 © 2012 Canadian Society for Chemical Engineering DOI 10.1002/cjce.21691 Published online in Wiley Online Library (wileyonlinelibrary.com). | VOLUME 9999, 2012 | | THE CANADIAN JOURNAL OF CHEMICAL ENGINEERING | 1 |