ASSESSMENT OF THE EFFECTIVENESS OF NATURAL ZEOLITES FOR REMOVAL OF AMMONIUM AND ZINC FROM THEIR DILUTE SOLUTIONS.

The adsorption of NH//4** plus and Zn**2** plus by four Korean zeolite samples which contained clinoptilolite, mordenite or both was measured by adding solutions containing NH//4** plus , Zn**2** plus , or both, each at a concentration ranging from 1 to 7 meq. /l. Both single and successive equilibrations of the sample with the solution showed that clinoptilolite and mordenite have a certain number of NH//4** plus -selective exchange sites but not Zn**2** plus -selective exchange sites. The successive equilibrations were useful to assess the effectiveness of zeolite for removal of NH//4** plus and Zn**2** plus . Mordenite and clinoptilolite would adsorb NH//4** plus corresponding to 40-45 percent and 30 percent of its cation exchange capacity (CEC), respectively, from the solution containing both NH//4** plus and Zn**2** plus each at 3 meq. /l. The corresponding adsorption of Zn**2** plus would be 5-10 percent of the CEC of each mineral.