Adsorption of Pb (II), Cu (II), and Zn (II) Ions onto iUrtica dioica/i Leaves (UDL) as a Low Cost Adsorbent: Equilibrium and Thermodynamic Studies

摘要

The biosorption of Cu (II), Zn (II) and Pb (II) ions from aqueous solution onto dried biomass (iUrtica dioica/i leaves) is discussed in the present study. The effect of variation of contact time, adsorbent dose, pH, concentration of metal ions and temperature on biosorption of metal ion is studied. Maximum adsorption was recorded for initial metal ion concentration of 10 mg/l, adsorbent dose of 2 gm, at pH 5 with 60 minutes of contact time for Lead and Zinc, 45 minutes of contact time for Copper ion. The equilibrium conditions were well described by Langmuir, Freundlich and Temkin isotherm equations. The Langmuir isotherm model have provided a better fit with the experimental data compared to that of Freundlich and Temkin isotherm models. The values of thermodynamic parameters indicate that the adsorption reactions were spontaneous, feasible and exothermic.