Study On Modification Of Zeolite And Its Adsorption Of Ammonia Nitrogen And Heavy Metal

In recent years, in order to improve the ion-exchange properties of zeoliteminerals, strengthening its ammonic nitrogen and heavy metal ions removal capability,expanding its scope of application for the purpose of physical and chemicalmodification of the zeolite is become a hot research and development in China andabroad.Based on the review and abroad modified zeolite research and development, thispaper carry out the modification in a deep-going way, and study of three singlemodifications and their combinations of modified methods on zeolite to carry outremoval of ammonium ions and three kinds of heavy metal ions study and exploremodified zeolite exchange adsorption mechanism, as a natural clinoptilolitedevelopment and provide a theoretical basis for further processing.Experimental results show that the natural zeolite by "salt+acid+hightemperature" modified zeolite obtained the optimal treatment, for ammonium andthree heavy metals adsorption. Specific approach is natural zeolite after NaCltreatment after washing clean, then treatment with HCl, and finally calcined at450℃.Determination of the use of the specific surface area, cation exchange capacitymeasurement, scanning electron microscopy, X-ray diffraction and Fourier transforminfrared spectroscopy five different tests conduct a comprehensive analysis of thephysicochemical properties of natural and modified zeolite, shows a microscopicdifference in all aspects of natural and modified zeolites. X-ray diffraction patternshows that the natural zeolite contains72%clinoptilolite composition and a portion ofthe quartz, mica and mineral substances, the "salt+acid+high temperature" modifiedzeolite component is no much change, but the modified sodium ion peak is higherthan other peaks, indicating that modification by salt of the natural zeolite is obvious;modified zeolite improves the specific surface area in a large extent, from14.20m~2/gto38.65m~2/g, the acid modified part take the aperture away impurities away, so that aperture is relatively increased; scanning electron microscopy shows the naturalzeolite and modified zeolite surface morphology, it can be seen that "salt+acid+high temperature" modified zeolite becomes more loose and more structured than thesurface morphology of natural zeolite, and conducive to a better adsorption; CEC(cation exchange capacity) showed that natural zeolite CEC is2.81±0.19mmol/g,and modified zeolite is CEC3.38±0.26mmol/g; Fourier transform infraredspectroscopy mainly analysis the organic compounds of the zeolite and shows that thecombination of modified zeolite water changes，this change is significantly caused bythe temperature modification.The adsorption capacity of the natural zeolite and zeolite modified by the "salt+acid+high temperature" to ammonia, copper ions, cadmium and lead ion respectivelyincrease from4.01mg/g,5.71mg/g,5.95mg/g and10.62mg/g to8.23mg/g,13.38mg/g,18.68mg/g and22.97mg/g, the increasing rates are2.05,2.34,3.12and2.16...