REMOVAL OF AMMONIUM IONS FROM WASTEWATER USING MODIFIED ZEOLITES

摘要

Ammonium removal by modified zeolites, Na-clinop-tilolite and Na-P, were studied by batch-type methods. The adsorption of ammonium on the modified zeolites was determined to be exothermic. The cation exchange capacities (CEC) of Na-clinoptilolite and Na-P were 21.68 and 33.72 mg NH_4~+/g, respectively. The exchange of ammonium ion from aqueous solutions in the concentration range of 50-250 mg NH_4~+/L onto the two zeolites was compared, and the equilibrium isotherms have been determined. Furthermore, the influence of other cations present in water on the ammonia removal was also studied. For Na-clinoptilolite, the effect of the metal ions suggested the following order of preference K~+ > Ca~(2+) > Mg~(2+). This contrasted with Na-P, where the order appeared to be Ca~(2+) > Mg~(2+) > K~+.