Fly‐Ash for the treatment of water enriched in lead (II)

Abstract

The removal of Pb(II) is dependent of contact time, concentration, pH and temperature, of the solution. The various rate parameters of adsorption, have been determined at different concentrations and temperatures for the present system. An empirical model has been tested to understand the kinetics of Pb(II) removal at different concentrations. The pore diffusion is mainly rate controlling step. The Langmuir isotherm has been applied to find out the adsorption parameters involved in the present adsorption process. The isosteric heat of adsorption has been determined at different surface coverages of the adsorbent. The negative value of enthalpy change (? H= ‐7.269 Kcal mol^‐1) suggests the exothermic nature of the adsorption process. The activation energy has been determined and found to be ‐8.533 Kjoules. The various thermodynamic parameters have been calculated to understand the clear mechanism involved in the adsorption process.

Key words:

• Fly ash
• adsorption kinetics
• pore diffusion
• empirical model
• mass transfer coefficient
• Langmuir isotherm
• activation energy
• isosteric heat
• thermodynamic parameters
• surface ionisation
• complexation.