Adsorption of bivalent lead ions from an aqueous phase system: Equilibrium, thermodynamic, kinetics, and optimization studies.

Abstract

Punica granatum carpellary membrane powder (PGCM) and its surface modified form (MPGCM) with 2,4-dinitrophenylhydrazine (2,4-DNP) were used as adsorbents for removal of bivalent lead ions from aqueous phase system. Batch mode experiments using various parameters were carried out to assess the adsorption isotherms and dynamics of the process. Langmuir isotherm was well-fitted model for experimental data. Langmuir adsorption capacity using PGCM and MPGCM at pH of 7 was found to be 169.49 and 196.07mg/g, respectively. Rate constant and thermodynamic parameters were calculated to evaluate the kinetic model and temperature dependence nature of adsorption. Box-Behnken design was applied to optimize the adsorption process of bivalent lead ions for PGCM and MPGCM using pH (3.0-9.0), initial bivalent lead ions concentration (20-100mg/L), contact time (20-180min), and temperature (20-60°C) parameters. The optimum conditions for maximum removal of bivalent lead ions on PGCM were found to be at pH of 6.99, initial bivalent lead ions concentration of 98.95, contact time of 176.05, and temperature of 21.20°C and on MPGCM at pH of 6.51, initial bivalent lead ions concentration of 99.99, contact time of 177.89, and temperature of 20.02°C, respectively. PRACTITIONER POINTS: Adsorption of bivalent lead from water using Punica granatum carpellary membrane powder and its modified form MPGCM is discussed. Batch mode experiments using various parameters were carried out to assess the adsorption isotherms and dynamics of the process. Langmuir adsorption capacity using PGCM and MPGCM at pH of 7 was found to be 169.49 and 196.07mg/g, respectively. Box-Behnken design was applied to optimize the adsorption process of bivalent lead ions.