TOXIC METAL IONS ADSORPTION ON BAGASSE FLY ASH

Abstract

Adsorption is an efficient and widely used technique for the treatment and recovery of the metal ion from the waste water. The bagasse fly ash has currently created an interest among the various workers to use it as an adsorbent for various metal ions. In this dissertation, an effort has been made to study the adsorption behavior of Pb(II) and Cd(II) ions on bagasse fly ash which is a by product of a sugar industry. Expeimental observations are collected at different initial metal ion concentration, pH variations, temperature variations, contact time variations and at different weight of the fly ash and result are suitably interpreted. An increasing trend in uptake amount of the metal ions on increasing the initial concentration of the metal ion at fixed pH and temperature has been obrserved. On increacing the pH of the medium, the uptake amount the of metal ion by the bagasse fly ash has also shown an increasing trend. There was maximum uptake of metal ions at pH-7 which clearly indicated that bagasse fly ash can be used efficiently in neutral media. Effect of temperature on adsorption of metal ions has suitably explained and data were used to calculate various thermodynamic parameters, such as AG, AH and AS. There was a decrease in the value of free energy change (AG)during adsorption of Pb (II) ion and Cd(II) ions on bagasse fly ash which suggested for the feasibility and spontaneity of the adsorption process. The metal ion uptake has increased on increasing the weight of the adsorbent but the efficiency of the adsorbent has decreased on increasing the weight of the adsorbent. The experimental data have been fitted well in Langmuir's adsorption isotherm from which adsorption parameter K, and IS have been calculated.