EXTRACTION OF IONS OF SOME TRANSITION ELEMENTS AND THEIR AMMONIA COMPLEXES FROM SOLUTIONS ON Na-CLINOPTYLOLITE AND Na-MORDENITE

Abstract

Modified natural zeolites in the Na-form (clinoptilolite tuff of the Aydag and mordenite of the Chananab deposits in Azerbaijan) were studied in order to extract cations of the transition and heavy metals water and industrial liquid waste. The equilibrium and kinetic characteristics of the sorption process under static and dynamic conditions have been studied. Distribution isotherms of exchange ions between Na forms of zeolites with chloride (Ni2+, Co2+, Cu2+, Zn2+, Сd2+) and nitric acid (Hg+, Ag+) solutions have been obtained. It has been found that the increased selectivity of Na-zeolites to metal cations is due to their pronounced selectivity with respect to Ag+ ions over the entire range of concentration changes in solution and solid phase, as well as to cations in the ammonium form ([Ni(NH3)6]2+, [Co(NH3)6]2+, [Cu(NH3)4]2+, [Cd(NH3)6]2+, [Zn(NH3)4]2+) from low selectivity and selectivity to cations in the usual form. This fact makes it possible to extract the studied cations from the mixture in the form of ammonia, in accordance with the established range of selectivity of Na-zeolites to non-ferrous cations and their ammonia complexes