In concentrated phosphoric acid (85% H3PO4) sorption capacity of the zeolite with respect to cadmium is in direct proportion to the process duration and increases throughout the studied time interval. After 60 mins, degree of cadmium sorption reaches 90.76%. With respect to lead, zeolite exhibits the highest sorption capacity at 40 mins, and over that time, lead sorption is reduced. However, most of the concentrated phosphoric acid, as in the previous experiment, the lead is absorbed in cations. So, even if the optimal time for of adsorbed cation sorption, cadmium is 90.8%, and lead-91.84%.
Physico-chemical methods of analysis (IR, electron-microscopic, X-ray) have shown that in leadcontaining phosphoric acid natural zeolite is activated without destroying the structure and absorbs lead, as well as in conjunction with the cadmium cations.