Adsorption Studies of Heavy Metals on Tectona Grandis: Removal and Recovery of Zn (II) from Electroplating Wastes

Abstract

Teak leaves (Tectona grandis), an inexpensive material has been utilized as an adsorbent for the removal of Zn (II) from aqueous solutions as well as from industrial waste. The effects of contact time, pH, concentration, temperature and adsorbent dosage on the removal of Zn (II) have been studied. The percent removal of different metals on teak leaves has been found in the order: Zn (II) > Cd (II) > Ni (II) > Cr (VI). Thermodynamic parameters like free energy, entropy and enthalpy changes for the adsorption of Zn (II) have been computed and discussed. The kinetics and the factor controlling the adsorption process have also been studied. The analytical application has been demonstrated by removing Zn (II) from electroplating waste water using batch as well as column operations. The recovery by column operation was found to be higher (96%) than that by batch process (76%).

Keywords:

• Adsorption
• desorption
• isotherms
• regeneration
• teak leave
• Zn (II)