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 metal, adsorption, kinetics, isotherm, thermodynamic