Untreated Zeolite Research Articles

天然ゼオライトの表面処理とその特性

The adsorption of dyes (direct, acidic, basic, reactive and disperse) on Itaya zeolite consisting mainly of clinoptilolite and mordenite was investigated.The adsorption isotherms were found to be approximately expressed by the Freundlich equation. The order of adsorption selectivity was basic dye>acidic dye>other dyes.The Itaya zeolite surface-treated by the disperse dye and binder has less adsorbing power to nitrogen than the untreated zeolite, but has about the same hydrogen and ammonium ion exchange capacity. Therefore, it is useful for soil for gardening, an ornament rock for cleaning of water in an aquarium and for building materials (for example, breathing walls).

ゼオライト鉱物の活性化と廃水中の重金属処理

The adsorptivity of a natural zeolite used for the removal of heavy metal ions in waste water is generally lower than that of the synthetic zeolite. The activation treatment of natural zeolite, therefore, has been studied in order to increase the, adsorptivitv. Natural zeolitesw ere treated with the solutions containing various amounts of NaOH, NaCl, KOH, NH4Cl, CaCl2 and HCl. The treatment effect was then evaluated concerning to the amounts of adsorbed heavy metal ions. The results obtained in this study are summerized as follows.(1) The natural zeolites could be activated by the treatment with NaOH, NaCl, KOH and NH4Cl solution.(2) The most effective activation was obtained when treated for an hour with about 1N solution of NaOH and NaCl on heating. The amounts of adsorbed heavy metal ionsreached 3 or 4 times larger than that of the untreated zeolite. The ion exchange capacity of activated natural zeolite showed nearly the same value as synthetic zeolite.(3) Theeffects of the activation treatment were found to be different as to the occurrence and the composition of zeolite tuffs.(4) The amounts of adsorbed ions decreased when naturalzeolite was treated with HCl solution. However, if this is subjected to further treatment with NaOH and NaCl solution after HCl treatment, the zeolite showed higher adsorptivitythan the original zeolite. This treatment condition was found applicable to the retreatment of used zeolite.