Regeneration of natural zeolite polluted by lead and zinc in wastewater treatment systems.

The aim of this work was to investigate the potential regeneration of natural zeolite which had been contaminated with lead and zinc contained in aqueous solutions, treated secondary effluent and primary treated wastewater. Several desorbing solutions were examined for the removal of Pb(II) and Zn(II) from zeolite and the highest desorption efficiency was obtained for 3M KCl and 1M KCl, respectively. The desorption process depended on the type and concentration of the desorbing solution, the metal being desorbed, the mineral selectivity towards the metal and the composition of the liquid medium where the adsorption process had taken place.