NATURAL ZEOLITE CLINOPTILOLITE AS ADSORBENT FOR CLEANING WATERS FROM ARSENIC IONS

The article presents the results of researches the adsorption of As (III) in cationic (As³⁺) and in anionic (AsO3 ^3- ) forms from water solutions on different adsorbents, obtained from natural zeolite Clinoptilolite (CL) of deposits of Georgia. The influence of various parameters such as effect of pH, contact time, initial arsenic concentration, temperature and sorbent dosage was studied. It was found that in the process of adsorption As³⁺ cations on zeolites are implemented in two mechanisms: ion exchange and donor-acceptor. Sorption of As³⁺ ions occurs by substitution of H⁺ ions in hydroxyl groups of zeolites, and by exchange the adsorbed ion with compensate cations of the zeolite. During the adsorption of the anionic form AsO3 ^3- , physical adsorption predominates.