نتایج جستجو برای: iranian natural zeolites

تعداد نتایج: 524536  

2007
George F. Vance Hongting Zhao Michael A. Urynowicz Girisha K. Ganjegunte Robert W. Gregory

Fast development of the coalbed natural gas (CBNG) industry in many parts of the western U.S. has resulted in the co-production of potentially salinesodic waters, hereafter referred to as CBNG water. Management of CBNG water is a major environmental challenge because of its quantity and quality. In this study, the potential utilization of calcium (Ca)-rich natural zeolites were examined for rem...

Abstract Background and purpose: Natural zeolites are widely used for the purification of water and wastewater. Nevertheless the selectivity of clinoptilolite (a common zeolite mineral) for cadmium is known to be particularly low. In order to enhance the zeolites’ sorption capacity for cadmium, we treated natural clinoptilolite with sulfuric acid solutions and investigated the sorption of ca...

Journal: :journal of sciences islamic republic of iran 0

amygdaloidal, cavity- and fracture-filling zeolites in eocene volcanic rocks from the kuh-e-aradeh of southern kahrizak, in the northernmost part of central iran have been studied in some detail by optical, chemical analysis, sem, and xrd techniques. the zeolites identified, in order of their relative time of formation from early to late, are tetranatrolite, analcime, natrolite, mesolite, stilb...

ذاکری, حسن , ربانی, صادق , قاسمی, حسین , کاظمیان, حسین ,

In this research, the synthesize possibility of Potassium Nickel Hexacyanoferrate complex on natural clinoptilolite, as a support for removal of Cs+ and Sr+2 from radioactive waste, was investigated. Previous work showed that in the high concentration of sodium ion the sorption of these radionuclides on zeolites is low, therefore we enhance the efficiency for the purpose with loading Potas...

2016
Yuran Wang Jennifer D. Lewis Yuriy Romań-Leshkov

Lewis acidic zeolites are used to synthesize unsaturated dicarboxylic acid esters via aldol condensation of keto esters. Hafnium-containing BEA (Hf-BEA) zeolites catalyze the condensation of ethyl pyruvate into diethyl 2methyl-4-oxopent-2-enedioate and diethyl 2-methylene-4oxopentanedioate (an itaconic acid ester analogue) with a selectivity of ca. 80% at ca. 60% conversion in a packed-bed reac...

2012
G. W. Qiao K. H. Kuo

Application of high resolution electron microscopy (HREM) to the study of Pt-Sn/y-Al20 3 supported catalyst, zeolites, iron catalyst for ammonia synthesis, rare-earth oxide catalysts, etc., is described. Micro-twins, dislocations and other crystallographic imperfections are observed. Moreover, the structure images of channels representing columns of cages in several kinds of zeolites as well as...

2008
Shujiang Yang Mohammed Lach-hab Iosif I. Vaisman Estela Blaisten-Barojas

—A machine learning approach is applied to classify zeolite crystals according to their framework type. The Zeolite-Structure-Predictor is introduced based on the Random Forest algorithm. Zeolites structural data from the Inorganic Crystal Structure Database (ICSD) are used to train the model. The ZSP uses sixteen attributes including topological descriptors obtained with statistical geometry a...

Journal: :Ultrasonics sonochemistry 2015
Danutė Vaičiukynienė Aras Kantautas Vitoldas Vaitkevičius Leonas Jakevičius Žymantas Rudžionis Mantas Paškevičius

The synthesis of zeolite NaA from silica by-product was carried out in the presence of 20 kHz ultrasound at room temperature. Zeolites obtained in this type of synthesis were compared to zeolites obtained by performing conventional static syntheses under similar conditions. The sonication effects on zeolite NaA synthesis were characterized by phase identification, crystallinity etc. The effects...

Journal: :Journal of the American Chemical Society 2004
Roope Astala Scott M Auerbach

All-silica zeolite frameworks doped with methylene and amine groups are studied using density functional theory-based electron structure calculations. Strain energies are calculated in a novel way, by comparing zeolite energies with appropriate polymer reference systems. The modified zeolites are found to be mechanically stable structures with surprisingly little strain. Distortions due to impu...

Ahmad Reza Yari, Emad Dehghanifard, Gagik Badalians Gholikandi, Mohammad Mehdi Baneshi, Saeed Salehi,

Background: There are great resources of natural zeolite in Iran. Zeolite, an inorganic ion-exchanger, may be used as a suitable technical-economical solution for water treatment in many regions of Iran. In this study, the characterization of natural zeolite natrolite and the feasibility of removing hardness, cations, and anions were investigated. Methods: First, zeolite composition and type...

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