POSSIBILITIES FOR USE OF NATURAL RAW MATERIALS FOR REMOVAL OF HEAVY METALS FROM AQUEOUS SOLUTIONS

This paper presented a comparison of natural raw materials, such as natural zeolite (clinoptilolite) from Kardjali, Bulgaria, zeolite bearing tuff from Vetunica, Kratovo, Macedonia and opalized tuff from Strmos, Probistip, Macedonia as an adsorbents for the removal of copper, zinc, manganese and lead ions from synthetic aqueous solutions. The experiments were performed under batch conditions from single ion solutions at initial concentration of metal ions 25 mg/l, mass of adsorbent 5 g, initial pH =3.5, temperature of 20 +/- 1 degrees C and agitation at 400 rpm up to 360 min. The examination of these natural raw materials led to the conclusion that adsorption of heavy metal ions onto used materials occurs efficiently and the zeolite bearing tuff gives best results. A little lower efficiency is noted for the natural zeolite (clinoptilolite), while the opalized tuff shows the smallest power of adsorption compared to that of the zeolite bearing tuff and the clinoptilolite.