International Journal of Environmental Sciences

Volume 3 Issue 6 2013- June 2013    Pages: 2048-2067  <<Previous    Next>>

A comparative study of 8-hydroxyquinoline-5-sulphonic acid and its 7-nitro derivative loaded on F-400 granular activated carbon for removal of copper ions from aqueous solutions

Author Information:

Doss V.R, Kodolikar S.P

Department of Chemical Engineering, Sinhgad College of Engineering, Vadgaon (Bk), Pune -411041, Maharashtra, India

ABSTRACT

The purpose of this study was to compare 8-hydroxyquinoline -5-sulphonic acid (QSA) and its 7- nitro derivative (NQSA) loaded on F-400 GAC as a suitable adsorbent material for adsorption of Cu ions in aqueous solutions. Batch experiments were performed to evaluate effect of various parameters like pH, contact time, temperature, agitation speed, etc. Kinetic studies were done which showed 90.14% removal of copper for QSA and 94.19% removal for NQSA. The adsorption isotherm data were validated to Langmuir, Freundlich and DR isotherms. Kinetic data showed that it follows pseudo second order kinetics for both QSA and NQSA. The thermodynamic parameters of the adsorption process like Gibb’s free energy, entropy and enthalpy were also determined for both the ligands. The Langmuir constants have been calculated at different temperatures and the adsorption is found to be exothermic (∆ H = -36.08 kJ/mole for QSA and ∆ H = -48.11 kJ/mole for NQSA). Maximum removal is observed at pH 5.5 for both the ligands. It has been observed in the qe values that even though NQSA is adsorbed to a marginally lower extent than QSA, it is able to remove more copper than QSA because of proper orientation to form a 1:2 complex with copper ions on the surface of ligand loaded GAC. The results demonstrates that NQSA loaded GAC has an edge over QSA as an effective adsorbent for removal of copper ions. The 7-nitro derivative owing to its bulky nature shows better adsorption capacity.

Keywords: Adsorption, Isotherms, Kinetics, Thermodynamics, Heavy metals, Ligands, 8-hydroxyquinoline -5-sulphonic acid and Granular Activated Carbon.

DOI:10.6088/ijes.2013030600024

© 2013 Copyright by the authors, licensee Integrated Publishing Association.This is an open access article distributed under the Creative Commons Attribution License (3.0) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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