Title: Removal of cadmium, chromium, copper, lead and zinc ions by alisma plantago aquatica
Authors: E.R. Ushakumary; G. Madhu
Addresses: Department of Chemical Engineering, Government Engineering College, Kozhikode – 673 005, Kerala, India ' Chemical Engineering Group, School of Engineering, Cochin University of Science and Technology, Kochi – 682 022, Kerala, India
Abstract: Heavy metals are major toxic pollutants with severe health effects on humans. They are released into the environment from a variety of industrial activities. Alisma plantago aquatica (APA) was used as adsorbent to remove Cd(II), Pb (II), Zn(II) Cr(III) and Cu(II) from aqueous solution. The batch kinetic studies revealed that the adsorption was influenced by initial pH, concentration and temperature. Adsorption isotherm models like Langmuir and Freundlich were used to analyse the equilibrium data. Temperature change in the range 20-50°C affected the adsorption capacity. Enthalpy data revealed that the adsorption is endothermic in nature. Equilibrium is described by Langmuir isotherm. Isotherm studies have been used to determine the thermodynamic parameters of the process. The adsorption kinetic data was fitted with second order kinetic model than first order model. FTIR analysis of alisma plantago aquatica revealed the presence of hydroxyl, carboxyl and carbonyl groups which are participating in the adsorption of metal ions.
Keywords: heavy metals; adsorption; kinetics; isotherm; thermodynamics; heavy metal removal; cadmium; chromium; copper; lead; zinc; alisma plantago aquatica; environmental pollution; water pollution; modelling.
DOI: 10.1504/IJEWM.2014.058796
International Journal of Environment and Waste Management, 2014 Vol.13 No.1, pp.75 - 89
Received: 07 Jul 2012
Accepted: 27 Dec 2012
Published online: 13 May 2014 *