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For investigating the effectiveness of Korean natural zeolite for removal of NH₄^+ in waste waters containing NH₄^+ and Cu^(2+), the adsorption of NH₄^+ and Cu^(2+) by three Korean natural zeolite samples, which contained mordenite and/or clinoptilolite, was measured by adding solutions containing NH₄^+ and Cu^(2+) or both at a concentration range from 1 to 7 mmol(+)/L of each cation. In the solutions, the zeolite samples adsorbed more amounts of NH₄^+ than Cu^(2+). By seven successive equilibrations, Korean natural zeolites adsorbed NH₄^+ corresponding to 23∼33% of those cation exchange capacity from the solution containing both NH₄^+ and Cu^(2+) at 3 mmol(+)/L of each cation. Whereas, the corresponding adsorption of Cu^(2+) was 17-27% of the CEC. Korean natural zeolite exhibited selectivity for NH₄^+ but not for Cu^(2+). Nevertheless, it using as a soil amendment after removing of NH₄^+ in waste waters should be carefully controlled on the application rate.
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