Natural zeolites occur in over 40 countries and are mined in 11 of these at a rate of around 250 thousand tonnes per year. Discovery of the characteristic ion-exchange, dehydration and selective-adsorption properties of these zeolites, which are related to their unique honeycomb structure, stimulated the development of severa1 processes for the manufacture of synthetic zeolites. These synthetic...

the purpose of this study was to find a relatively inexpensive method for removal of arsenate and arsenite from drinking water. the capability of iranian natural clinoptilolites, relevant synthetic zeolites a and p and iron(п) modified of them was investigated for the uptake of arsenic anions from drinking water. data obtained from ion-exchange using batch (static) technique showed that among t...

zeolites a, x and hs were synthesized from natural iranian kaolinite by alkaline fusion,,followed by refluxing the mixture. the transformation of zeolites x to hs and y to p were studied at different time intervals by x-ray diffraction and scanning electron microscopy (sem). it was revealed that in solution, zeolites hs and p are more stable than zeolites x and y respectively

Zeolites A, X and HS were synthesized from natural Iranian Kaolinite by alkaline fusion,,followed by refluxing the mixture. The transformation of zeolites X to HS and Y to P were studied at different time intervals by X-ray diffraction and Scanning Electron Microscopy (SEM). It was revealed that in solution, zeolites HS and P are more stable than zeolites X and Y respectively

results the batch kinetics experiments showed that nom adsorption by the adsorbents followed the pseudo-second order model. results showed that the acidic ph is optimum for adsorption of nom by smz. conclusions the findings of this study show that natural zeolite modified with sodium dodecyl sulfate, as a cationic surfactant, is a promising adsorbent for removal of nom. materials and methods in...

ammonia in air can be hazardous to human and animal life and should be removed from the environment. recently the removal of environmental pollutants such as ammonia by means of natural and modified zeolites has attracted a lot of attention and interests. in this study the capability of three iranian natural zeolites (clinoptilolite) in point of view of removal of ammonia from air was investiga...

the main object of this study was to compare the natural and synthetic( naa and nam) zeolites as absorbents in removing emulsified and dissolved traces of organic compounds, which appear in the wastewater of  power plants, refinery and petrochemical complexes.  the specific objectives of the work was: a) to select the best species that have the highest amount of absorption; b) to measure the ra...

Natural and modified zeolites (0.5-1.0 mm) from the Tasajera deposit in Cuba were used to enhance the anaerobic digestion process of synthetic substrates. Natural zeolites were modified by ionic exchange and by adsorption with nickel, cobalt and magnesium. The experiments were carried out by using an inoculum from a full-scale anaerobic reactor treating winery wastewater. Modified natural zeoli...