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Sample records for natural zeolite clinoptilolite

  1. Sorption of 60 Co in natural zeolite (clinoptilolite)

    International Nuclear Information System (INIS)

    Hernandez B, E.

    1996-01-01

    A Mexican zeolite (clinoptilolite) from Taxco, Guerrero, was partially stabilized with sodium cations. Radioactive Cobalt ( 60 Co) was used to study the Co 2+ sorption in the stabilized zeolite (Na + ). It was found that sorption in general does not favour the diffusion of cobalt between framework, it explains because of it is a natural zeolite and its composition heterogeneous decrease its exchange capacity by the generated competence to the existence other type of exchange ions. The cobalt retention reached the highest level, around 0.408 m eq Co 2+ /g in the Na-Clinoptilolite. The crystallinity of the aluminosilicates was maintained during experiments, it was verified by XRD patterns. (Author)

  2. Characterization of natural zeolite clinoptilolite for sorption of contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Xingu-Contreras, E., E-mail: nyleve-18@hotmail.com; García-Rosales, G., E-mail: gegaromx@yahoo.com.mx [Instituto Tecnológico de Toluca (Mexico); García-Sosa, I., E-mail: irma.garcia@inin.gob.mx; Cabral-Prieto, A., E-mail: agustin.cabral@inin.gob.mx; Solache-Ríos, M., E-mail: marcos.solache@inin.gob.mx [Instituto Nacional de Investigaciones Nucleares, Departamento de Química (Mexico)

    2015-06-15

    The nanoparticles technology has received considerable attention for its potential applications in groundwater treatment for the removal of various pollutants as Cadmium. In this work, iron boride nanoparticles were synthesized in pure form and in presence of homo-ionized zeolite clinoptilolite, as support material. These materials were used for removing Cd (II) from aqueous solutions containing 10, 50, 100, 150, 200, 250, 300 and 400 mg/L. The characterization of these materials was made by using X-ray Diffraction, Scanning Electron Microscopy and Mössbauer Spectroscopy. Pure iron boride particles show a broad X-ray diffraction peak centered at 45{sup ∘} (2θ), inferring the presence of nanocrystals of Fe{sub 2}B as identified from Mössbauer Spectroscopy. The size of these Fe{sub 2}B particles was within the range of 50 and 120 nm. The maximum sorption capacities for Cd (II) of iron boride particles and supported iron boride particles in homo-ionized zeolitic material were nearly 100 %. For homo-ionized zeolite and homo-ionized zeolite plus sodium borohydride was ≥ 95 %.

  3. Evaluation of natural zeolite clinoptilolite efficiency for the removal of ammonium and nitrate from aquatic solutions

    Directory of Open Access Journals (Sweden)

    Mozhdeh Murkani

    2015-01-01

    Full Text Available Background: Surface water and groundwater pollution with various forms of nitrogen such as ammonium and nitrate ions is one of the main environmental risks. The major objectives of this study were to evaluate the capacity of natural zeolite (clinoptilolite to remove NO3– and NH4+ from polluted water under both batch and column conditions. Methods: The laboratory batch and column experiments were conducted to investigate the feasibility of clinoptilolite as the adsorbent for removal of nitrate (NO3– and ammonium (NH4+ ions from aqueous solution. The effects of pH, clinoptilolite dosage, contact time, and initial metal ion concentration on NO3– and NH4+ removal were investigated in a batch system. Results: Equilibrium time for NO3– and NH4+ ions exchange was 60 minutes and the optimum adsorbent dosage for their removal was 1 and 2.5 g/L, respectively. The adsorption isotherm of reaction (r> 0.9 and optimum entered concentration of ammonium and nitrate (30 and 6.5 mg/L, respectively were in accordance with Freundlich isotherm model. The ammonium removal rate increased by 98% after increasing the contact time. Conclusion: Our findings confirmed that natural Clinoptilolite can be used as one of effective, suitable, and low-costing adsorbent for removing ammonium from polluted waters.

  4. Infrared spectroscopic examination of the interaction of urea with the naturally occurring zeolite clinoptilolite

    Science.gov (United States)

    Byler, D.M.; Gerasimowicz, W.V.; Stockette, V.M.; Eberl, D.D.

    1991-01-01

    Infrared spectroscopy has shown for the first time that the naturally occurring zeolite clinoptilolite can absorb urea, (NH2)2CO, under ambient conditions from either aqueous or ethanolic solutions. The two strongest NH stretching bands at 3441 and 3344 cm-1 in pure, solid urea shift to higher frequency (about 3504 and 3401 cm-1) after absorption. Two of the four urea bands in the 1800-1300 cm-1 range (at 1683 and 1467 cm-1) undergo marked downward shifts to about 1670 and 1445 cm-1. The other two bands show little change in frequency. The strong band at 1602 cm-1, however, diminishes in intensity to little more than an ill-defined shoulder on the 1626-cm-1 peak. When clinoptilolite is heated to 450 ??C and then treated with molten urea (ca. 140 ??C) for several minutes, and finally washed twice with ethanol to remove excess unreacted urea, further changes become apparent in the spectrum of the urea-treated clinoptilolite. The two NH stretching bands broaden without significant change in frequency. Two new bands appear in the midfrequency range at 1777 (weak) and 1719 (medium strong) cm-1. Of the four original midfrequency peaks, the one at 1602 cm-1 is now absent. Two others (1627 and 1440 cm-1) exhibit little change, while the fourth has broadened and shifted down to 1663 cm-1, where it appears as a shoulder on the band at 1627 cm-1. Both treatments clearly induce interaction between urea and the zeolite which seems to result in significant modifications in the nature of the hydrogen bonding of the substrate. ?? 1991.

  5. Leaching and antimicrobial properties of silver nanoparticles loaded onto natural zeolite clinoptilolite by ion exchange and wet impregnation

    CSIR Research Space (South Africa)

    Missengue, RNM

    2015-11-01

    Full Text Available This study aimed to compare the leaching and antimicrobial properties of silver that was loaded onto the natural zeolite clinoptilolite by ion exchange and wet impregnation. Silver ions were reduced using sodium borohydride (NaBH(sub4...

  6. Gas-phase adsorption in dealuminated natural clinoptilolite and liquid-phase adsorption in commercial DAY zeolite and modified ammonium Y zeolite

    Science.gov (United States)

    Costa Hernandez, Alba Nydia

    The adsorption of Carbon Dioxide (CO2) is a very important tool for the material characterization. On the other hand, in separation and recovery technology, the adsorption of the CO2 is important to reduce the concentration of this gas considered as one of the greenhouse gases. Natural zeolites, particularly clinoptilolite, are widely applied to eliminate some pollutants from the environment. One of the goals of this research is to study the structure, composition and morphology of one natural clinoptilolite dealuminated with ammonium hexafluorosilicate (AHFi) and with orthophosphoric acid (H3PO4). Each modified sample was characterized using X-ray Diffraction (XRD), Carbon Dioxide adsorption at 0° C, Thermogravimetric Analysis (TGA), and Scanning Electron Microscopy with Energy Dispersive X-Ray Analysis (SEM-EDAX). In addition, the surface chemistry of the modified clinoptilolites was analyzed with Diffuse Reflectance Fourier Transform Infrared Spectroscopy (DRIFTS). The adsorption measurements were also used to study of the interaction of CO2 molecule within the adsorption space of these modified clinoptilolites. It was concluded that one of the modified clinoptilolites, (CSW-HFSi-0.1M), showed a great quality as adsorbent and as catalytic comparable to commercial synthetic zeolites. As far as we know, the modification of clinoptilolite with HFSi to improve their adsorption properties had not been previously attempted. In the second part of this dissertation, the dynamic adsorption of three isomers of nitrophenols using as adsorbent a commercial DAY zeolite was investigated. Also, the dynamic adsorption of methanol in a less hydrophobic zeolite, Ammonium Y Zeolite was investigated. The obtained breakthrough curves showed that the commercial DAY zeolite could be a suitable adsorbent to the liquid-phase adsorption of the phenolic compounds. Notwithstanding the modified ammonium Y zeolite had a low Si/Al ratio (less hydrophobic) than commercial DAY zeolite; this

  7. Arsenic removal from groundwater by MnO{sub 2}-modified natural clinoptilolite zeolite: Effects of pH and initial feed concentration

    Energy Technology Data Exchange (ETDEWEB)

    Camacho, Lucy M. [Chemical Engineering Department, New Mexico State University, P.O. Box 30001, MSC 3805, 1040 S. Horseshoe St, Las Cruces, NM 88003 (United States); Parra, Ramona R. [Physical Science Laboratory, New Mexico State University, P.O. Box 30001, MSC 3805, Las Cruces, NM 88003 (United States); Deng, Shuguang, E-mail: sdeng@nmsu.edu [Chemical Engineering Department, New Mexico State University, P.O. Box 30001, MSC 3805, 1040 S. Horseshoe St, Las Cruces, NM 88003 (United States)

    2011-05-15

    Adsorption of arsenic (As{sup 5+}) on natural and MnO{sub 2}-modified clinoptilolite-Ca zeolite adsorbents was investigated to explore the feasibility of removing arsenic from groundwater using natural zeolite adsorbents. The natural and MnO{sub 2}-modified clinoptilolite-Ca zeolite adsorbents were characterized with nitrogen adsorption at 77 K for pore textural properties, scanning electron microscopy with energy dispersive X-ray spectroscopy and X-ray fluorescence for morphology, elemental composition and distribution. Batch adsorption equilibrium experiments were conducted to study the effects of pH and initial feed concentration on arsenic removal efficiency. It was found that the amphoteric properties and arsenic removal efficiency of the natural clinoptilolite-Ca zeolite were significantly improved after modification with MnO{sub 2}. The MnO{sub 2}-modified zeolite could effectively remove arsenic from water at a wide pH range, and the arsenic removal efficiency that is basically independent of the pH of feed solutions varies slightly with the initial arsenic concentration in the feed solutions. The removal efficiency obtained on the modified zeolite was doubled as compared to that obtained on the unmodified zeolite. The MnO{sub 2}-modified clinoptilolite-Ca zeolite appears to be a promising adsorbent for removing trace arsenic amounts from water.

  8. Leaching and antimicrobial properties of silver nanoparticles loaded onto natural zeolite clinoptilolite by ion exchange and wet impregnation.

    Science.gov (United States)

    Missengue, Roland N M; Musyoka, Nicholas M; Madzivire, Godfrey; Babajide, Omotola; Fatoba, Ojo O; Tuffin, Marla; Petrik, Leslie F

    2016-01-28

    This study aimed to compare the leaching and antimicrobial properties of silver that was loaded onto the natural zeolite clinoptilolite by ion exchange and wet impregnation. Silver ions were reduced using sodium borohydride (NaBH 4 ). The leaching of silver from the prepared silver-clinoptilolite (Ag-EHC) nanocomposite samples and their antimicrobial activity on Escherichia coli Epi 300 were investigated. It was observed that the percentage of silver loaded onto EHC depended on the loading procedure and the concentration of silver precursor used. Up to 87% of silver was loaded onto EHC by wet impregnation. The size of synthesized silver nanoparticles varied between 8.71-72.67 nm and 7.93-73.91 nm when silver was loaded by ion exchange and wet impregnation, respectively. The antimicrobial activity of the prepared nanocomposite samples was related to the concentration of silver precursor used, the leaching rate and the size of silver nanoparticles obtained after reduction. However, only in the case of the nanocomposite sample (Ag-WEHC) obtained after loading 43.80 ± 1.90 µg of Ag per gram zeolite through wet impregnation was the leaching rate lower than 0.1 mg L -1 limit recommended by WHO, with an acceptable microbial killing effect.

  9. Regeneration of clinoptilolite zeolite used for the ammonium removal

    International Nuclear Information System (INIS)

    Garcia G, M.C.

    2002-01-01

    The use of zeolites has been increased in the last years with different applications and with a great boom in the environmental area, but a little had been make about the regeneration of such zeolites. The presence of nitrogen-ammonia in water may cause serious pollution problems since it results to be toxic for fishes and other aquatic life forms, also it provokes the algae growing. The natural clinoptilolite contains interchangeable ions such as the sodium (Na + ), potassium (K + ), magnesium (Mg 2+ ) and calcium (Ca 2+ ) in different proportions depending on the mineral origin When the zeolite is upgraded to its sodium form, the cation exchange capacity and the preference by the nitrogen-ammonia are increased, allowing the reversible process of sorption. In this work it was proposed the regeneration to its sodium form about the ammonia clinoptilolite zeolite. The natural mineral was characterized using the methods such as: X-ray diffraction, Infrared spectroscopy, Thermal gravimetric analysis and surface area. The results show that the ammonium sorption was between 95% and 98.7% such an ambient temperature as a flow back. the zeolite was regenerated approximately from 60% in the first cycle up to 97% in the last cycle at flow back temperature and of 59.2% up to 96.9% at ambient temperature, it was not presented any significant effect which could be attributed to the temperature. During the exchange process, the cations present in the natural zeolite were exchanged with the ammonium ions, this process was not completed due to that retained ammonium quantity was major that of the desorpted ions, what shows that in addition of ion exchange, another type of sorption process exists. (Author)

  10. The effect of feeding clinoptilolite (zeolite) to laying hens

    African Journals Online (AJOL)

    The effect of feeding clinoptilolite (zeolite) to laying hens. M.D. Olver. Animal and Dairy Science Research Institute, lrene. One hundred and twenty 4-month-old, single-combed, brown. Hy-Line pullets were fed two isocaloric diets containing 16 or. 13,5o/o protein with and without 5% clinoptilolite in four.

  11. Sonochemical synthesis of zeolite NaP from clinoptilolite.

    Science.gov (United States)

    Behin, Jamshid; Kazemian, Hossein; Rohani, Sohrab

    2016-01-01

    In the present work, natural clinoptilolite was converted to zeolite NaP using ultrasonic energy, in which the transformation time shortened remarkably. The effect of post-synthesis treatment using conventional hydrothermal was also investigated. The synthesized powders were characterized by XRD, TGA/DTA, SEM, and PSD analysis. The results showed that, increasing the sonication time (energy) has no significant effect on the product's morphology. The crystallinity of the synthesized samples increased slightly with increasing sonication time, but their yield remained relatively unchanged. Furthermore, post-synthesis hydrothermal treatment showed very little influence on properties of the final product. Because the ultrasonic irradiation creates acoustic cavitation cracks on the surface structure of clinoptilolite particulates and increases the concentration of soluble alumino-silicate species, which favors the prevailing super-saturation, crystallization and crystal growth of zeolite NaP happen faster. The particles of zeolite NaP synthesized by ultrasonic irradiation consist of small crystallites of uniform size. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. The selection and performance of the natural zeolite clinoptilolite in British Nuclear Fuels' site ion exchange effluent plant, SIXEP

    International Nuclear Information System (INIS)

    Baxter, S.G.; Berghauser, D.C.

    1986-01-01

    SIXEP has been conducted by British Nuclear Fuels plc at its Sellafield reprocessing site as part of its committment to reduce radioactive discharges to the Irish Sea. An extensive development program identified the natural ion exchange mineral clinoptilolite, from a particular deposit in California now owned by Tenneco Specialty Minerals, as the most suitable for use in SIXEP to extract caesium and strontium from spent nuclear fuel storage pond water. Close cooperation with the supplier in a Quality Assurance scheme ensured the supply of a fully-characterised, high grade ion exchanger. Since SIXEP commenced treating pond water on 28 May 1985, the plant has performed well, exceeding the design expectation in terms of discharge reduction and availability

  13. Sorption of cobalt in zeolites and natural clays of the clinoptilolite and kaolinite type; Sorcion de cobalto en zeolitas y arcillas naturales del tipo clinoptilolita y caolinita

    Energy Technology Data Exchange (ETDEWEB)

    Davila R, J.I.; Solache R, M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2006-07-01

    In this work the sorption of cobalt of aqueous solutions in two natural zeolites (clinoptilolite) and a clay (kaolinite) of origin in the center-north region of Mexico is evaluated. The effect of the pH and the time of contact in the process of sorption were evaluated. The cobalt retained in the aluminosilicates was determined by neutron activation analysis. The cobalt sorption in the materials in a range of pH from 4 to 7 does not present significant variations. The studies of reaction kinetics show a very fast sorption in the first 5 hours of contact, reaching the equilibrium in approximately 24 hours. The kinetics of sorption of the cobalt ions was represented better by the Ritchie reaction model modified of second order. The experimental data for the zeolites obtained at ambient temperature and varying the concentration were adjusted to the models of Freundlich, Langmuir and Freundlich-Langmuir isotherms and it was observed that the cobalt sorption it behaves according to the Freundlich isotherm model. (Author)

  14. Comparison of Granular Activated Carbon, Natural Clinoptilolite Zeolite, and Anthracite Packed Columns in Removing Mercury from Drinking Water

    Directory of Open Access Journals (Sweden)

    Mohammad Taghi Samadi

    2010-01-01

    Full Text Available Development of effective methods for the removal of such pollutants as heavy metals (e.g., mercury from surface and ground water resources introduced by municipal and industrial wastewaters seems to be inevitable, especially in the face of the importance of water reuse in combating water shortages, limited availability of water resources, and imminent risks of a water crisis in Iran. A number of methods are already available for the removal of mercury from water resources. However, these techniques must be investigated for their practicability and economy, in addition to their not only effectiveness. In this research, granular activated carbon, natural zeolite, and anthracite packed-columns were investigated as cheap and effective adsorbents for the removal of mercury. Moreover, the effects of changes in pH (6-8, influent mercury concentrations (0.25, 0.5, 0.75, and 1 ppm, contact time (0.5, 1, 2, 3 hr were investigated. Mercury concentration in the samples was determined using a ditizon indicator and spectrophotometry at 492 nm. Results showed that decreasing influent mercury concentration from 1 ppm to 0.25 ppm (under constant conditions increased the removal efficiencies of anthracite, granular activated carbon, and zeolite columns from22%, 63%, and 55% to 28%, 72%, and 64%, respectively. Increasing contact time from 0.5 hr to 3 hr caused the removal efficiencies of these columns to increase from 22%, 56%, and 54% to 42%, 86%, and 82%, respectively. Also, increasing pH level led to increased removal efficiencies of the studied columns. It was found that contact time played a more effective role in enhancing mercury removal efficiency in the granular activated carbon column than in the other two columns. The ranges of mercury removal efficiency obtained for the granular activated carbon, natural zeolite, and anthracite columns under various conditions were (51%-92%, (42%-88%, and (16%-52%, respectively. Based on these results, granular

  15. Influences of clinoptilolite and surfactant-modified clinoptilolite zeolite on nitrate leaching and plant growth

    International Nuclear Information System (INIS)

    Malekian, Raheleh; Abedi-Koupai, Jahangir; Eslamian, Sayed Saeid

    2011-01-01

    The increasing demands for environmental protection and sustainable food production require an increase in the use of natural and non-toxic materials for agriculture. In this study, the feasibility of using surfactant-modified zeolite (SMZ) in comparison with zeolite clinoptilolite (Cp) application to reduce nitrate leaching and enhance crop growth was investigated. The effects of size (millimeter and nanometer) and application rate (20 g kg -1 and 60 g kg -1 ) of Cp and SMZ on nitrate leaching and crop response were also evaluated. Using soil lysimeters, it was determined that the maximum and mean nitrate concentration in the leachate of SMZ-amended soil were significantly (p 3 -N leached from SMZ- and Cp-amended lysimeters at the higher application rate (60 g kg -1 ) was approximately 26% and 22% lower, respectively, than that from the control system. The mean grain yield, grain nitrogen content, stover dry matter, and N uptake were significantly greater in Cp-amended than SMZ-amended lysimeters. There was no significant effect due to the particle size of the two soil amendments. The results implicitly suggest that plants may have a better response if Cp is used as a fertilizer carrier rather than SMZ when applied at a rate of 60 g kg -1 .

  16. Geopolymer materials based on natural zeolite

    NARCIS (Netherlands)

    Nikolov, A.; Rostovsky, Ivan; Nugteren, H.W.

    2017-01-01

    One of the potential raw materials for preparation of geopolymers is the natural zeolite. In the present report, the used natural zeolite (clinoptilolite) is from huge deposit near Beli Plast, Bulgaria. Geopolymer pastes and mortars are prepared by using three different alkaline activators—sodium

  17. Comparative study of cerium (IV) sorptive properties in zeolite Y and clinoptilolite

    International Nuclear Information System (INIS)

    Garcia D, O.C.

    1993-01-01

    Among the problems of protecting the environment from radioactive contamination, the reduction of radioactive releases by improving monitoring, decontamination, and burial methods is one of the most important. Natural sorbents are gaining increased significance for solving this problem. Among these, zeolites deserve special attention since they have sufficient sorptive capacity, are highly radiation resistant, are widely distributed exhibit selectivity and are inexpensive. In the present work we determine experimentally the sorptive characteristics of clinoptilolite as a function of various factors and demonstrate that clinoptilolite is capable of sorbing Ce(IV) over a wide pH range. (Author)

  18. THERMODYNAMICS OF ION-EXCHANGED NATURAL CLINOPTILOLITE

    Science.gov (United States)

    Natural clinoptilolite from Castle Creek, Idaho, and its cation-exchanged variants (Na-Cpt, NaK-Cpt, K-Cpt, and Ca-Cpt) were studied by high-temperature calorimetry. The hydration enthalpy for all clinoptilolites is about -30 kJ/mol H2O (liquid water reference state) at 25 C. T...

  19. Calculation of chemical composition of zeolites in mordenite-clinoptilolite rocks

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    А.Д. Кустовська

    2005-01-01

    Full Text Available  Individual chemical composition of mordenite and clinoptilolite, which are both found in zeolite rocks and acid modification effect on them have been calculated. For the purpose of this study, samples of rocks of the same deposit (village Lypcha, Transcarpatia with different content of mordenite and clinoptilolite have been used.

  20. Nuclear waste treatment using Iranian natural zeolites

    International Nuclear Information System (INIS)

    Kazemian, H.; Ghannadi Maraghe, M.

    2001-01-01

    Full text: The zeolite researches in Iran is a relatively new subject which has started about 10 years ago. The motivation for this scientific and interesting field was provided after discovery of significant deposits of natural zeolites in different regions of Iran as well as further developments of research institutions and the national concern to environmental protection especially the wastewater clean-up in point of view of recycling of such waste water to compensate some needs to water in other utilizations. This paper intends to review and describes scientific researches which have done on using zeolites in the field of nuclear waste treatment in Iran to introduce the potential resources to the world in more details. Zeolite tuffs are widely distributed in huge deposits in different regions of Iran. So far, the clinoptilolite tuffs are the most abundant natural zeolite which exist with zeolite content of 65%- 95%. Nowadays several different types of Iranian natural zeolites are characterized in point of view of chemical composition, type of structure, chemical, thermal, and radiation resistance using different instrumental and classical methods such as; X-ray diffraction (XRD), X-ray fluoresce (XRF), thermal methods of analysis (TA), scanning electron microscopy (SEM), analytical chemistry and radioanalytical methods as well as different ion-exchange techniques (e.g.3-7). The ability of Iranian natural clinoptilolite for removal of some fission products from nuclear wastewaters have been investigated. The selectivity of all investigated zeolites toward radiocesium and radiostrontium have been promising (e.g. 8-10). The successful synthesize of P zeolite from Iranian clinoptilolite-reach tuffs under different conditions were performed. The compatibility of zeolites with glass and cement matrices, for final disposal of radwaste, as well as their selectivity toward most dangerous heat generating radionuclides (e.g. 137 Cs and 90 Sr) is very important in using

  1. ION EXCHANGE MECHANISM OF Cr+3 ON NATURALLY OCCURRING CLINOPTILOLITE

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    M.A.S.D. de Barros

    1997-09-01

    Full Text Available Ion exchange isotherms are very important tools to achieve a better comprehension of cation removal by means of zeolite treatment. In this work, three isotherms were obtained (at 298K, at 313K and at 333K from natural pretreated Na+ clinoptilolite. The ion exchange was carried out with Cr+3 ions. The isotherms’ shape is similar to the classical type "b" isotherm, according to the arrangement proposed by Breck (1984. Mathematical fitting was applied to the experimental points (Table Curve software to obtain a representative curve thereof. From such fittings, points were simulated and then used to construct the Kielland plots, whose shape was associated with an ion exchange mechanism. Straight lines were obtained as an indication that, although the zeolite used is of natural occurrence and presents impurities such as mordenite and clays, only one site is involved in the ion exchange process

  2. New insights into alkylammonium-functionalized clinoptilolite and Na-P1 zeolite: Structural and textural features

    Science.gov (United States)

    Muir, Barbara; Matusik, Jakub; Bajda, Tomasz

    2016-01-01

    The area of zeolites' application could be expanded by utilizing their surfaces. Zeolites are frequently modified to increase their hydrophobicity and to generate the negative charge of the surface. The main objective of the study was to investigate and compare the features of natural clinoptilolite and synthetic zeolite Na-P1 modified by selected surfactants involving quaternary ammonium salts. The FTIR study indicates that with increasing carbon chain length in the surfactant attached to the zeolites surface the molecules adopt a more disordered structure. FTIR was also used to determine the efficiency of surface modification. Thermal analysis revealed that the presence of surfactant results in additional exothermic effects associated with the breaking of electrostatic bonds between zeolites and surfactants. The mass losses are in line with ECEC and CHN data. The textural study indicates that the synthetic zeolite Na-P1 has better sorption properties than natural clinoptilolite. The modification process always reduces the SBET and porosity of the material. With an increasing carbon chain length of surfactants all the texture parameters decrease.

  3. Formaldehyde Adsorption into Clinoptilolite Zeolite Modified with the Addition of Rich Materials and Desorption Performance Using Microwave Heating

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    Amin Kalantarifard

    2016-01-01

    Full Text Available Granite, bentonite, and starch were mixed with clinoptilolite zeolite to produce a modified zeolite. The modified zeolite was tested for its ability to absorb formaldehyde from air. The modified sample formaldehyde adsorption capacity was then compared with those of commercially available clinoptilolite, faujasite (Y, mordenite, and zeolite type A. Studies were focused on the relationships between the physical characteristics of the selected zeolites (crystal structure, surface porosity, pore volume, pore size and their formaldehyde adsorption capacity. The removal of starch at high temperature (1100°C and addition of bentonite during modified clinoptilolite zeolite (M-CLZ preparation generated large pores and a higher pore distribution on the sample surface, which resulted in higher adsorption capacity. The formaldehyde adsorption capacities of M-CLZ, clinoptilolite, faujasite (Y, zeolite type A, and mordenite were determined to be 300.5, 194.5, 123.7, 106.7, and 70 mg per gram of zeolite, respectively. The M-CLZ, clinoptilolite, and faujasite (Y crystals contained both mesoporous and microporous structures, which resulted in greater adsorption, while the zeolite type A crystal showed a layered structure and lower surface porosity, which was less advantageous for formaldehyde adsorption. Furthermore, zeolite regeneration using microwave heating was investigated focusing on formaldehyde removal by desorption from the zeolite samples. XRD, XRF, N2 adsorption/desorption, and FE-SEM experiments were performed to characterize the surface structure and textural properties the zeolites selected in this study.

  4. Environmental application of modified natural zeolites

    International Nuclear Information System (INIS)

    Nikashina, V.A.; Myasoedov, B.F.

    1998-01-01

    The following techniques were used for the chemical modification of the natural zeolites: (1) treatment of natural zeolites with organic substances. Examples of applications of these sorbents to the decontamination and disinfection of solutions of different composition and surface waters are presented. (2) Treatment of the natural zeolites with a inorganic substances. (2.1) The clinoptilolite-rich tuffs were treated with a hot suspensions of freshly precipitated magnetite. This leads to the preparation of sorbents possessing magnetic properties. The radionuclides and heavy metals recovery from soils and silts was investigated using different soil and ferromagnetic zeolite weights ratios and contact times. Different soils and sorbent of varying capacities were used for these investigations. As example, the recovery 137 Cs and 85 Sr from soils of different nature is presented. (2.2) Treatment of natural zeolites with Fe-containing solutions of Fe-containing natural waters. The filtration of these solutions through clinoptilolite-rich tuffs makes leads to preparation of materials possessing high selectivity to PO 4 3- ions. The properties of these sorbents can be utilized for the PO 4 3+ decontamination of waters (e.g. waste waters) and for the subsequent use of these materials in agriculture as fertilizers.(author)

  5. Enriched natural zeolites – mineral fertilizer

    Directory of Open Access Journals (Sweden)

    Rybárová Lucia

    2001-12-01

    Full Text Available Clinoptilolit belongs to the big group of minerals called zeolites. Chemically they are alumosilicates and have a very difficult crystal structure. Nature zeolites are used as sorbents, molecular sieves and catalyzators. Their application is also in agriculture and horticulture. Endeavour of all agricurtural subjects from the plant area is to reach a maximum efficiency and production.Charges for the fertilization are 14 – 40% of all charges depending on the structure of product, intensity of production and share of nutrition in soil. For the elimination of the loss in the nutrition matter, it is possible to use a „porter“, which secures a regular and inteligent supply of nutrition to plants.Regarding the physical and chemical properties is good to use natural zeolites as a „porter“.The experiments were made with enriched zeolites, and their influences an vegetables and flowers roots was reserched. Results were positive.

  6. Regeneration of clinoptilolite zeolite used for the ammonium removal; Regeneracion de zeolita clinoptilolita empleada para la remocion de amonio

    Energy Technology Data Exchange (ETDEWEB)

    Garcia G, M.C

    2002-07-01

    The use of zeolites has been increased in the last years with different applications and with a great boom in the environmental area, but a little had been make about the regeneration of such zeolites. The presence of nitrogen-ammonia in water may cause serious pollution problems since it results to be toxic for fishes and other aquatic life forms, also it provokes the algae growing. The natural clinoptilolite contains interchangeable ions such as the sodium (Na{sup +}), potassium (K{sup +}), magnesium (Mg{sup 2+}) and calcium (Ca{sup 2+}) in different proportions depending on the mineral origin When the zeolite is upgraded to its sodium form, the cation exchange capacity and the preference by the nitrogen-ammonia are increased, allowing the reversible process of sorption. In this work it was proposed the regeneration to its sodium form about the ammonia clinoptilolite zeolite. The natural mineral was characterized using the methods such as: X-ray diffraction, Infrared spectroscopy, Thermal gravimetric analysis and surface area. The results show that the ammonium sorption was between 95% and 98.7% such an ambient temperature as a flow back. the zeolite was regenerated approximately from 60% in the first cycle up to 97% in the last cycle at flow back temperature and of 59.2% up to 96.9% at ambient temperature, it was not presented any significant effect which could be attributed to the temperature. During the exchange process, the cations present in the natural zeolite were exchanged with the ammonium ions, this process was not completed due to that retained ammonium quantity was major that of the desorpted ions, what shows that in addition of ion exchange, another type of sorption process exists. (Author)

  7. Investigation of Ammonium Saturation and Desorption Conditions of Clinoptilolite Type Zeolite in Aquarium Conditions

    Directory of Open Access Journals (Sweden)

    Meryem Öz

    2017-12-01

    Full Text Available In this research, it was aimed to determine the adsorption, saturation reaching and desorption effects of ammonium, which is one of the parameters that should be kept in control for aquarium life, by clinoptilolite type zeolite which is a natural filtration material. In the aquarium water, Z1: 20 mg/l TAN and Z2: 40 mg/l TAN concentrations were determined to have adsorption up to Z1: 10 mg/l TAN and Z2: 24 mg/l TAN concentration at the end of the experiment period. After this phase, where zeolites had reached saturation, desorption system was created, and 2 groups were formed with 5-liter research aquariums and 3 repetitions. During the five-days test, water parameters were determined daily and at the same time of day (10.00. At the beginning of the experiment, mean values of 0.4 ± 0.00 mg / l TAN in Z1 and Z2 groups were determined at the end of the experiment as 1.55 ± 0.176 mg/l (15.5% and 2.153 ± 0.27 mg/l (13.5% TAN in Z1 and Z2 groups, respectively. When the data obtained in this study were evaluated, zeolite was determined to make desorption periodically in proportion with the amount of retained ammonium, when it reached the saturation. In intensive aquaculture systems or aquarium conditions, recondition of zeolite for necessary periods is recommended to be performed by considering these data.

  8. The Usage of Natural Zeolites for the Adsorption of Radionuclides, particularly in emergency situations

    International Nuclear Information System (INIS)

    Reitbauer, Franz

    2012-09-01

    Specific natural zeolites have proven their capability to bind nuclear radiation During the last decades, numerous research work has proven the potential of natural zeolites to adsorb nuclear radiation through their cation exchange properties. Zeolites have been used successfully in Chernobyl, and are used in Fukushima and in nuclear waste repositories today. Within the various kinds of zeolites the special type clinoptilolite particularly binds 137-cesium as well as 90- strontium ions. Therefore zeolites with high contents of clinoptilolite are the first choice for this purpose. High contents of clinoptilolite can be defined as being above 90 %. Such zeolites are typically capable of binding some 2,50 meq/g of cesium ions and some 1,40 meq/g of strontium ions. (authors)

  9. Use of natural zeolite-supplemented litter increased broiler production

    African Journals Online (AJOL)

    The aim of this study was to ascertain the influence of natural zeolite, consisting mainly of clinoptilolite and mordenite, as a component of the litter material in broiler houses on the performance of the broilers and on some litter characteristics. Live weight gain, feed consumption, feed efficiency, viability and leg and body ...

  10. Use of natural zeolite-supplemented litter increased broiler production

    African Journals Online (AJOL)

    smyo

    Abstract. The aim of this study was to ascertain the influence of natural zeolite, consisting mainly of clinoptilolite and mordenite, as a component of the litter material in broiler houses on the performance of the broilers and on some litter characteristics. Live weight gain, feed consumption, feed efficiency, viability and leg and ...

  11. Removal of cadmium in urban wastewater with systems based on zeolite type clinoptilolite

    International Nuclear Information System (INIS)

    Barragan P, P.

    2016-01-01

    From an environmental issue detected in wastewater samples taken in a municipal wastewater collector in Nogales, Sonora, which is related to cadmium pollution, a research project came out where the principal aim was to implement a system to remove metallic ions of cadmium in wastewater, based on modified and unmodified natural zeolites. The zeolitic material used was natural clinoptilolite modified with NaCl and thiourea, sourced in El Cajon and Guaymas, Sonora. The materials were characterized with X-ray diffraction, Sem, Ft-IR spectra, and Bet analysis. The kinetics of four modified zeolites was investigated at ph=5 and initial concentration of 30 mgL -1 of Cd 2+ . The pseudo-first, the pseudo-second order, and Elovich models were applied to the experimental results. The results best fitted to pseudo-second order model. The maximum sorption capacity of modified zeolites was investigated through isotherms, The Langmuir model, Freundlich, and the combined Langmuir-Freundlich models were applied to the experimental results afterwards. ZGuayThio showed the highest sorption capacity, 11.60 mgg -1 , with R 2 =0.978 according to Langmuir-Freundlich model. Fixed-bed column adsorption experiments were carried out with ZGuayNa and ZGuayThio with three bed heights with 30 mgL -1 solution of Cd 2+ . influent at a flow rate of 1 mLmin -1 , at ph=5. The Thomas, mass balance, and Bed Depth Service Time models were applied to the results. The dynamic adsorption capacity (No) and the constant of sorption velocity (K a) were determined, 28.67 gL -1 and 0.072 Lg -1 min -1 respectively for ZGuayNa with R 2 = 0.9954. Column experiments with municipal wastewater from Colinas del Yaqui sub-collector, previously characterized, were conducted using ZGuayNa and ZGuayThio. A mass transference model was applied to the results which accounted for K p = 0.815 m 3 Kg - 1 with R 2 = 0.9789 for ZGuayNa, and K p = 3.1 m 3 Kg - 1 for ZGuayThio with R 2 = 0.78. Finally, the capacity of the column

  12. Treatments of reverse osmosis concentrate using natural zeolites

    Directory of Open Access Journals (Sweden)

    Taherifar Hossein

    2015-06-01

    Full Text Available The purpose of the current study is to experimentally investigate the reduction of sodium adsorption ratio (SAR from a concentrated stream of reversed osmosis (RO using natural zeolites. In order to reduce the salinity of solution, experiments were carried out using zeolites of varying concentration, pretreatment of adsorbents, and the addition of Ethylenediaminetetraacetic acid (EDTA. The results show that both zeolites can be used in an RO brine treatment; however, Rhyolitic tuff is more effective than clinoptilolite for the reduction of water salinity. The experiments show that Rhyolitic tuff decreases salinity of RO concentrate to nearly one – third of the initial value. Statistical analyses show that the effect of zeolite concentration is negligible. Furthermore, the addition of EDTA and pretreatment of zeolite increase the SAR values.

  13. Structural simulation of natural zeolites; Simulacion estructural de zeolitas naturales

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez P, E.; Carrera G, L.M. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    The application of X-ray diffraction (XRD) in the study of crystalline structures of the natural and modified zeolites allows the identification, lattice parameter determination and the crystallinity grade of the sample of interest. Until two decades ago, simulation methods of X-ray diffraction patterns were developed with which was possible to do reliable determinations of their crystalline structure. In this work it is presented the first stage of the crystalline structure simulation of zeolitic material from Etla, Oaxaca which has been studied for using it in the steam production industry and purification of industrial water. So that the natural material was modified for increasing its sodium contents and this material in its turn was put in contact with aqueous solutions of Na, Mg and Ca carbonates. All the simulations were done with the Lazy-Pulverix method. The considered phase was clinoptilolite. It was done the comparison with three clinoptilolite reported in the literature. (Author)

  14. Iodide adsorption on the surface of chemically pretreated clinoptilolite

    International Nuclear Information System (INIS)

    Chmielewska-Horvatova, E.; Lesny, J.

    1995-01-01

    The possibility to use the monoionic Ag +- form (eventually Hg +- and Hg 2+ -forms) of clinoptilolite of domestic origin for radioactive iodide elimination from waters has been studied. The capacity of the monoforms of clinoptilolite towards iodide exceeds many times that of the capacity of clinoptilolite in natural form. Due to the low solubility product of AgI, Hg 2 I 2 and HgI 2 iodides generate precipitates on the zeolite surface. Rtg analyses of the silver form of clinoptilolite after sorption of iodide demonstrate the formation of new crystals on the zeolite surface. The influence of interfering anions on the adsorption capacity of silver clinoptilolite towards iodide was investigated, too. Kinetic curves of iodide desorption from the surface of silver and mercury clinoptilolite were compared. Simultaneously, adsorption isotherms for the systems aqueous iodide solution/Ag-, Hg-clinoptilolite were determined. (author) 6 refs.; 7 figs.; 4 tabs

  15. Dissolution of Iron During Biochemical Leaching of Natural Zeolite

    Directory of Open Access Journals (Sweden)

    Lengauer C.

    2004-12-01

    Full Text Available Natural zeolite, including clinoptilolite, often contains iron and manganese which decrease the whiteness of this sharp angular material.The biological treatment of zeolite enables its use as an substitute for tripolyphosphates in wash powders which have to comply with strict requirements as far as whiteness is concerned and rounded off grain content. Insoluble Fe3+ and Mn4+ in the zeolite could be reduced to soluble Fe2+ and Mn2+ by silicate bacteria of Bacillus spp. These metals were efficiently removed from zeolite as documented by Fe2O3 decrease (from 1.37% to 1.08% and MnO decrease (from 0.022% to 0.005% after bioleaching. The whiteness of zeolite was increased by 8%. The leaching effect, observed by scanning electron microscopy, caused also a chamfer of the edges of sharp angular grains. Despite the enrichment by fine-grained fraction, the decrease of the surface area of clinoptilolite grains from the value 24.94 m2/g to value 22.53 m2/g was observed. This fact confirms the activity of bacteria of Bacillus genus in the edge corrosion of mineral grains.Removal of iron and manganese as well as of sharp edges together with the whiteness increase would provide a product suitable for industrial applications.

  16. Review of the thermal stability and cation exchange properties of the zeolite minerals clinoptilolite, mordenite, and analcime; applications to radioactive waste isolation in silicic tuff

    International Nuclear Information System (INIS)

    Smyth, J.R.; Caporuscio, F.A.

    1981-06-01

    Silicic tuffs of the southern Great Basin and basalts of the Columbia River Plateau are under investigation as potential host rocks for high- and intermediate-level radioactive wastes. Nonwelded and partially welded tuffs may contain major amounts (> 50%) of the zeolite minerals clinoptilolite, mordenite, and analcime. Densely welded tuffs and some basalt flows may contain clinoptilolite as fracture filling that limits the permeability of these rocks. The cation exchange properties of these zeolite minerals allow them to pose a formidable natural barrier to the migration of cationic species of various radionuclides in aqueous solutions. However, these minerals are unstable at elevated temperatures and at low water-vapor pressures and may break down either by reversible dehydration or by irreversible mineralogical reactions. All the breakdown reactions occurring at increased temperature involve a net volume reduction and evolution of fluids. Thus, they may provide a pathway (shrinkage fractures) and a driving force (fluid pressure) for release of radionuclides to the biosphere. These reactions may be avoided by keeping zeolite-bearing horizons saturated with water and below about 85 0 C. This may restrict allowable gross thermal loadings in waste repositories in volcanic rocks

  17. Compost maturity and nitrogen availability by co-composting of paddy husk and chicken manure amended with clinoptilolite zeolite.

    Science.gov (United States)

    Latifah, Omar; Ahmed, Osumanu Haruna; Susilawati, Kassim; Majid, Nik Muhamad

    2015-04-01

    The availability of paddy husk from rice processing plants remains high owing to increase in the worldwide rice consumption. Increasing demand for chicken products leads to poultry wastes production. Co-composting of the aforementioned wastes could solve the indiscriminate disposal of these wastes. Thus, co-composting of paddy husk and chicken slurry with clinoptilolite zeolite and urea as additive was carried out. Clinoptilolite zeolite was used to enhance ammonium and nitrate retention in the compost. Temperature of the compost was monitored three times daily for 55 days. Cation exchange capacity, organic matter, ash, humic acids, pH, total C, N, C/N ratio; total P, exchangeable Ca, Mg, K, NH4+, NO3-, and heavy metals contents were determined using standard procedures. pH, total N, humic acids, ash, NH4+, NO3-, P, Ca, Mg, and K contents increased but the salinity, heavy metals contents, and microbial population were low after the co-composting process. Zea mays L. (test crop) seed germination rate in distilled water and the compost were not significantly different. Growth of Spinach oleracea (test crop) on a peat-based growing medium and the compost was also not significantly different. These findings were possible because the clinoptilolite zeolite used in co-composting reduced accumulation of heavy metals that may have damage effects on the test crops. Mature compost with good agronomic properties can be produced by co-composting chicken slurry and paddy husk using clinoptilolite zeolite and urea as additives. © The Author(s) 2015.

  18. Removal of pyridine from liquid and gas phase by copper forms of natural and synthetic zeolites

    Czech Academy of Sciences Publication Activity Database

    Reháková, M.; Fortunová, L.; Bastl, Zdeněk; Nagyová, S.; Dolinská, S.; Jorík, V.; Jóna, E.

    2011-01-01

    Roč. 186, č. 1 (2011), s. 699-706 ISSN 0304-3894 R&D Projects: GA AV ČR KAN100400702 Institutional research plan: CEZ:AV0Z40400503 Keywords : natural zeolite * clinoptilolite * ZSM5 Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.173, year: 2011

  19. Magnetically supported zeolite adsorbents for effluent treatment

    International Nuclear Information System (INIS)

    Gaydardjiev, S.

    1998-01-01

    An attempt was made to remove heavy metal ions from metallurgical effluents by means of magnetically supported fluidized bed column employing zeolite-magnetite complexes as adsorbents. The natural sorptive properties of acid modified clinoptilolite were used instead of synthetic beads. X-ray diffraction and DTA studies on the raw material confirmed that the main zeolite mineral was clinoptilolite. (author)

  20. Natural zeolite bitumen cracking

    Energy Technology Data Exchange (ETDEWEB)

    Kuznicki, S.M.; McCaffrey, W.C.; Bian, J.; Wangen, E.; Koenig, A. [Alberta Univ., Edmonton, AB (Canada). Dept. of Chemical and Materials Engineering

    2006-07-01

    A study was conducted to demonstrate how low cost heavy oil upgrading in the field could reduce the need for diluents while lowering the cost for pipelining. Low cost field upgrading could also contribute to lowering contaminant levels. The performance of visbreaking processes could be improved by using disposable cracking agents. In turn, the economics of field upgrading of in-situ derived bitumen would be improved. However, in order to be viable, such agents would have to be far less expensive than current commercial cracking catalysts. A platy natural zeolite was selected for modification and testing due to its unique chemical and morphological properties. A catalyst-bearing oil sand was then heat-treated for 1 hour at 400 degrees C in a sealed microreactor. Under these mild cracking conditions, the catalyst-bearing oil sand produced extractable products of much lower viscosity. The products also contained considerably more gas oil and middle distillates than raw oil sand processed under the same conditions as thermal cracking alone. According to model cracking studies using hexadecane, these modified mineral zeolites may be more active cracking agents than undiluted premium commercial FCC catalyst. These materials hold promise for partial upgrading schemes to reduce solvent requirements in the field. tabs., figs.

  1. Integrated treatment process using a natural Wyoming clinoptilolite for remediating produced waters from coalbed natural gas operations

    Science.gov (United States)

    Zhao, H.; Vance, G.F.; Urynowicz, M.A.; Gregory, R.W.

    2009-01-01

    Coalbed natural gas (CBNG) development in western U.S. states has resulted in an increase in an essential energy resource, but has also resulted in environmental impacts and additional regulatory needs. A concern associated with CBNG development relates to the production of the copious quantities of potentially saline-sodic groundwater required to recover the natural gas, hereafter referred to as CBNG water. Management of CBNG water is a major environmental challenge because of its quantity and quality. In this study, a locally available Na-rich natural zeolite (clinoptilolite) from Wyoming (WY) was examined for its potential to treat CBNG water to remove Na+ and lower the sodium adsorption ratio (SAR, mmol1/2 L- 1/2). The zeolite material was Ca-modified before being used in column experiments. Column breakthrough studies indicated that a metric tonne (1000??kg) of Ca-WY-zeolite could be used to treat 60,000??L of CBNG water in order to lower SAR of the CBNG water from 30 to an acceptable level of 10??mmol1/2 L- 1/2. An integrated treatment process using Na-WY-zeolite for alternately treating hard water and CBNG water was also examined for its potential to treat problematic waters in the region. Based on the results of this study, use of WY-zeolite appears to be a cost-effective water treatment technology for maximizing the beneficial use of poor-quality CBNG water. Ongoing studies are evaluating water treatment techniques involving infiltration ponds lined with zeolite. ?? 2008 Elsevier B.V. All rights reserved.

  2. Environmental applications of natural zeolitic materials based on their ion-exchange properties

    International Nuclear Information System (INIS)

    Colella, C.

    1998-01-01

    Natural zeolites, such as clinoptilolite, chabazite, phillipsite and mordenite, exhibit good selectivities for some water pollutants, e.g., Cs + , NH 4 + and Pb 2+ . Zeolite-rich tuffs may be therefore utilized for removing the above and other cations from wastewaters before discharge. Continuous processes with fixed beds are usually employed for water purification, such as those in service in the U.S.A for ammonium removal from municipal sewage. Direct action of the ion exchanger is needed when the pollutant must be removed from soil and trapped in the zeolite framework. Discontinuous processes (addition of zeolite to the waste solution) are also possible, provided the polluted zeolitic sludge is stabilized-solidified in a cement matrix matrix before disposal. Removal of radionuclides from nuclear power plant waters with natural zeolites is discussed

  3. Natural clinoptilolite exchanged with iron: characterization and catalytic activity in nitrogen monoxide reduction

    Directory of Open Access Journals (Sweden)

    Daria Tito-Ferro

    2016-12-01

    Full Text Available The aim of this work was to characterize the natural clinoptilolite from Tasajeras deposit, Cuba, modified by hydrothermal ion-exchange with solutions of iron (II sulfate and iron (III nitrate in acid medium. Besides this, its catalytic activity to reduce nitrogen monoxide with carbon monoxide/propene in the presence of oxygen was evaluated. The characterization was performed by Mössbauer and UV-Vis diffuse reflectance spectroscopies and adsorption measurements. The obtained results lead to conclude that in exchanged samples, incorporated divalent and trivalent irons are found in octahedral coordination. Both irons should be mainly in cationic extra-framework positions inside clinoptilolite channels as charge compensating cations, and also as iron oxy-hydroxides resulting from limited hydrolysis of these cations. The iron (III exchanged samples has a larger amount of iron oxy-hydroxides agglomerates. The iron (II exchanged samples have additionally iron (II sulfate adsorbed. The catalytic activity in the nitrogen monoxide reduction is higher in the exchanged zeolites than starting. Among all samples, those exchanged of iron (II has the higher catalytic activity. This lead to outline that, main catalytically active centers are associated with divalent iron.

  4. Thermal behavior of natural zeolites

    International Nuclear Information System (INIS)

    Bish, D.L.

    1993-01-01

    Thermal behavior of natural zeolites impacts their application and identification and varies significantly from zeolite to zeolite. Zeolites evolve H 2 0 upon heating, but recent data show that distinct ''types'' of water (e.g., loosely bound or tightly bound zeolitic water) do not exist. Rather water is bound primarily to extra-framework cations with a continuum of energies, giving rise to pseudocontinuous loss of water accompanied by a dynamic interaction between remaining H 2 0 molecules and extra-framework cations. These interactions in the channels of zeolites give rise to dehydration dependent on the extra-framework cation, in addition to temperature and water vapor pressure. The dehydration reaction and the extra-framework cation also affect the thermal expansion/contraction. Most zeolites undergo dehydration-induced contractions that may be anisotropic, although minor thermal expansion can be seen with some zeolites. Such contractions can be partially or completely irreversible if they involve modifications of the tetrahedral framework and/or if rehydration is sluggish. Thermally induced structural modifications are also driven initially by dehydration and the concomitant contraction and migration of extra-framework cations. Contraction is accommodated by rotations of structural units and tetrahedral cation-oxygen linkages may break. Thermal reactions that involve breaking of tetrahedral cation-oxygen bonds markedly irreversible and may be kinetically limited, producing large differences between short- and long-term heating

  5. Selective catalytic reduction of nitric oxide by ammonia over Cu-exchanged Cuban natural zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Moreno-Tost, Ramon; Santamaria-Gonzalez, Jose; Rodriguez-Castellon, Enrique; Jimenez-Lopez, Antonio [Departamento de Quimica Inorganica, Cristalografia y Mineralogia, Facultad de Ciencias, Unidad Asociada del Instituto de Catalisis y Petroleoquimica, CSIC, Universidad de Malaga, Campus de Teatinos, 29071 Malaga (Spain); Autie, Miguel A.; Glacial, Marisol Carreras [Centro Nacional de Investigaciones Cientificas, Ciudad de la Habana, La Habana (Cuba); Gonzalez, Edel [Instituto Superior Pedagogico ' Enrique Jose Varona' , La Habana (Cuba); Pozas, Carlos De las [Centro de Gerencia de Programas y Proyectos Priorizados, La Habana (Cuba)

    2004-07-15

    The catalytic selective reduction of NO over Cu-exchanged natural zeolites (mordenite (MP) and clinoptilolite (HC)) from Cuba using NH{sub 3} as reducing agent and in the presence of excess oxygen was studied. Cu(II)-exchanged zeolites are very active catalysts, with conversions of NO of 95%, a high selectivity to N{sub 2} at low temperatures, and exhibiting good water tolerance. The chemical state of the Cu(II) in exchanged zeolites was characterized by H{sub 2}-TPR and XPS. Cu(II)-exchanged clinoptilolite underwent a severe deactivation in the presence of SO{sub 2}. However, Cu(II)-exchanged mordenite not only maintained its catalytic activity, but even showed a slight improvement after 20h of reaction in the presence of 100ppm of SO{sub 2}.

  6. Selective catalytic reduction of nitric oxide by ammonia over Cu-exchanged Cuban natural zeolites

    International Nuclear Information System (INIS)

    Moreno-Tost, Ramon; Santamaria-Gonzalez, Jose; Rodriguez-Castellon, Enrique; Jimenez-Lopez, Antonio; Autie, Miguel A.; Glacial, Marisol Carreras; Gonzalez, Edel; Pozas, Carlos De las

    2004-01-01

    The catalytic selective reduction of NO over Cu-exchanged natural zeolites (mordenite (MP) and clinoptilolite (HC)) from Cuba using NH 3 as reducing agent and in the presence of excess oxygen was studied. Cu(II)-exchanged zeolites are very active catalysts, with conversions of NO of 95%, a high selectivity to N 2 at low temperatures, and exhibiting good water tolerance. The chemical state of the Cu(II) in exchanged zeolites was characterized by H 2 -TPR and XPS. Cu(II)-exchanged clinoptilolite underwent a severe deactivation in the presence of SO 2 . However, Cu(II)-exchanged mordenite not only maintained its catalytic activity, but even showed a slight improvement after 20h of reaction in the presence of 100ppm of SO 2

  7. Copper removal using bio-inspired polydopamine coated natural zeolites.

    Science.gov (United States)

    Yu, Yang; Shapter, Joseph G; Popelka-Filcoff, Rachel; Bennett, John W; Ellis, Amanda V

    2014-05-30

    Herein, for the first time, natural clinoptilolite-rich zeolite powders modified with a bio-inspired adhesive, polydopamine (PDA), have been systematically studied as an adsorbent for copper cations (Cu(II)) from aqueous solution. Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA) revealed successful grafting of PDA onto the zeolite surface. The effects of pH (2-5.5), PDA treatment time (3-24h), contact time (0 to 24h) and initial Cu(II) ion concentrations (1 to 500mgdm(-3)) on the adsorption of Cu(II) ions were studied using atomic absorption spectroscopy (AAS) and neutron activation analysis (NAA). The adsorption behavior was fitted to a Langmuir isotherm and shown to follow a pseudo-second-order reaction model. The maximum adsorption capacities of Cu(II) were shown to be 14.93mgg(-1) for pristine natural zeolite and 28.58mgg(-1) for PDA treated zeolite powders. This impressive 91.4% increase in Cu(II) ion adsorption capacity is attributed to the chelating ability of the PDA on the zeolite surface. Furthermore studies of recyclability using NAA showed that over 50% of the adsorbed copper could be removed in mild concentrations (0.01M or 0.1M) of either acid or base. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Effect of the temperature on the sorption of cadmium in natural clinoptilolite from the State of Chihuahua

    International Nuclear Information System (INIS)

    Arambula V, V.

    2004-01-01

    The investigation works related with the removal of cadmium of aqueous solutions, they make emphasis in a great number of materials that were used for this end, as well as in the parameters that influence, such as the temperature and the pH. In this work it was investigated the effect of the temperature on the removal of cadmium, using a zeolitic mineral native of the State of Chihuahua for they were determined it kinetic parameters, those diffusivity coefficients and the retention mechanisms (adsorption or ion exchange) involved. The clinoptilolite samples were characterized by means of scanning electron microscopy in high vacuum (MEB), elementary microanalysis (EDS) and X-ray diffraction (XRD). The experimental part consisted on putting in contact solutions of cadmium with the mineral, varying the temperature, the time of contact or the concentration; the quantification of sodium and cadmium in the liquid phase was carried out by means of atomic absorption spectroscopy (EAA). It was determined the time of equilibrium for the removal process. The temperature and the concentration influence on the process of sorption of cadmium in the zeolitic mineral (kinetics and isotherms). The kinetic model that describes better the sorption process of cadmium in the clinoptilolite was the pseudo-2 order. The apparent coefficient of diffusivity presented a greater value conforms to increment the temperature. The results of the isotherm of adsorption of cadmium presented a better adjustment to the Freundlich model. The quantity of cadmium retained by the mineral it was greater than the quantity of sodium found in the solution after the contact between the solution of cadmium and the zeolitic mineral and in accordance with the obtained separation factors, the natural zeolite shows a greater affinity for the cadmium that for the sodium (α > 1). (Author)

  9. Copper removal using bio-inspired polydopamine coated natural zeolites

    International Nuclear Information System (INIS)

    Yu, Yang; Shapter, Joseph G.; Popelka-Filcoff, Rachel; Bennett, John W.; Ellis, Amanda V.

    2014-01-01

    Highlights: • Natural zeolites were modified with bio-inspired polydopamine. • A 91.4% increase in Cu(II) ion adsorption capacity was observed. • Atomic absorption and neutron activation analysis gave corroborative results. • Neutron activation analysis was used to provide accurate information on 30+ elements. • Approximately 90% of the adsorbed copper could be recovered by 0.1 M HCl treatment. - Abstract: Herein, for the first time, natural clinoptilolite-rich zeolite powders modified with a bio-inspired adhesive, polydopamine (PDA), have been systematically studied as an adsorbent for copper cations (Cu(II)) from aqueous solution. Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA) revealed successful grafting of PDA onto the zeolite surface. The effects of pH (2–5.5), PDA treatment time (3–24 h), contact time (0 to 24 h) and initial Cu(II) ion concentrations (1 to 500 mg dm −3 ) on the adsorption of Cu(II) ions were studied using atomic absorption spectroscopy (AAS) and neutron activation analysis (NAA). The adsorption behavior was fitted to a Langmuir isotherm and shown to follow a pseudo-second-order reaction model. The maximum adsorption capacities of Cu(II) were shown to be 14.93 mg g −1 for pristine natural zeolite and 28.58 mg g −1 for PDA treated zeolite powders. This impressive 91.4% increase in Cu(II) ion adsorption capacity is attributed to the chelating ability of the PDA on the zeolite surface. Furthermore studies of recyclability using NAA showed that over 50% of the adsorbed copper could be removed in mild concentrations (0.01 M or 0.1 M) of either acid or base

  10. Oxidative regeneration of toluene-saturated natural zeolite by gaseous ozone: The influence of zeolite chemical surface characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Alejandro, Serguei [Laboratorio de Tecnologías Limpias (F. Ingeniería), Universidad Católica de la Santísima Concepción, Alonso de Ribera 2850, Concepción (Chile); Núcleo de Energías Renovables (F. Ingeniería), Universidad Católica de Temuco, Rudecindo Ortega 02950, Temuco (Chile); Valdés, Héctor, E-mail: hvaldes@ucsc.cl [Laboratorio de Tecnologías Limpias (F. Ingeniería), Universidad Católica de la Santísima Concepción, Alonso de Ribera 2850, Concepción (Chile); Manéro, Marie-Hélène [Université de Toulouse (France); INPT, UPS (France); Laboratoire de Génie Chimique, 4, Allée Emile Monso, F–31030 Toulouse (France); CNRS (France); Laboratoire de Génie Chimique, F–31030 Toulouse (France); Zaror, Claudio A. [Departamento de Ingeniería Química (F. Ingeniería), Universidad de Concepción, Concepción, Correo 3, Casilla 160–C (Chile)

    2014-06-01

    Highlights: • Surface acidity of modified natural zeolite is related to its chemical reactivity. • Brønsted acid sites are associated to toluene adsorption. • Lewis acid sites could decompose ozone generating surface active oxygen species. • Infrared spectra evidence active atomic oxygen and oxidation by-product formation. • 2NH4Z1 sample shows the highest reactivity toward adsorbed toluene. - Abstract: In this study, the effect of zeolite chemical surface characteristics on the oxidative regeneration of toluene saturated-zeolite samples is investigated. A Chilean natural zeolite (53% clinoptilolite, 40% mordenite and 7% quartz) was chemically modified by acid treatment with hydrochloric acid and by ion-exchange with ammonium sulphate. Thermal pre-treatments at 623 and 823 K were applied and six zeolite samples with different chemical surface characteristics were generated. Chemical modification of natural zeolite followed by thermal out-gassing allows distinguishing the role of acidic surface sites on the regeneration of exhausted zeolites. An increase in Brønsted acid sites on zeolite surface is observed as a result of ammonium-exchange treatment followed by thermal treatment at 623 K, thus increasing the adsorption capacity toward toluene. High ozone consumption could be associated to a high content of Lewis acid sites, since these could decompose ozone into atomic active oxygen species. Then, surface oxidation reactions could take part among adsorbed toluene at Brønsted acid sites and surface atomic oxygen species, reducing the amount of adsorbed toluene after the regenerative oxidation with ozone. Experimental results show that the presence of adsorbed oxidation by-products has a negative impact on the recovery of zeolite adsorption capacity.

  11. Oxidative regeneration of toluene-saturated natural zeolite by gaseous ozone: The influence of zeolite chemical surface characteristics

    International Nuclear Information System (INIS)

    Alejandro, Serguei; Valdés, Héctor; Manéro, Marie-Hélène; Zaror, Claudio A.

    2014-01-01

    Highlights: • Surface acidity of modified natural zeolite is related to its chemical reactivity. • Brønsted acid sites are associated to toluene adsorption. • Lewis acid sites could decompose ozone generating surface active oxygen species. • Infrared spectra evidence active atomic oxygen and oxidation by-product formation. • 2NH4Z1 sample shows the highest reactivity toward adsorbed toluene. - Abstract: In this study, the effect of zeolite chemical surface characteristics on the oxidative regeneration of toluene saturated-zeolite samples is investigated. A Chilean natural zeolite (53% clinoptilolite, 40% mordenite and 7% quartz) was chemically modified by acid treatment with hydrochloric acid and by ion-exchange with ammonium sulphate. Thermal pre-treatments at 623 and 823 K were applied and six zeolite samples with different chemical surface characteristics were generated. Chemical modification of natural zeolite followed by thermal out-gassing allows distinguishing the role of acidic surface sites on the regeneration of exhausted zeolites. An increase in Brønsted acid sites on zeolite surface is observed as a result of ammonium-exchange treatment followed by thermal treatment at 623 K, thus increasing the adsorption capacity toward toluene. High ozone consumption could be associated to a high content of Lewis acid sites, since these could decompose ozone into atomic active oxygen species. Then, surface oxidation reactions could take part among adsorbed toluene at Brønsted acid sites and surface atomic oxygen species, reducing the amount of adsorbed toluene after the regenerative oxidation with ozone. Experimental results show that the presence of adsorbed oxidation by-products has a negative impact on the recovery of zeolite adsorption capacity

  12. Improving saline-sodic coalbed natural gas water quality using natural zeolites.

    Science.gov (United States)

    Ganjegunte, Girisha K; Vance, George F; Gregory, Robert W; Urynowicz, Michael A; Surdam, Ronald C

    2011-01-01

    Management of saline-sodic water from the coalbed natural gas (CBNG) industry in the Powder River Basin (PRB) of Wyoming and Montana is a major environmental challenge. Clinoptilolie zeolites mined in Nevada, California, and New Mexico were evaluated for their potential to remove sodium (Na+) from CBNG waters. Based on the exchangeable cation composition, naturally occurring calcium (Ca2+)-rich zeolites from New Mexico were selected for further evaluation. Batch adsorption experiments were conducted to evaluate the potential of the Ca(2+)-rich natural clinoptilolites to remove Na+ from saline-sodic CBNG waters. Batch adsorption experiments indicated that Na+ adsorption capacity ofclinoptilolite ranged from 4.3 (4 x 6 mesh) to 7.98 g kg(-1) (14 x 40 mesh). Among the different adsorption isotherms investigated, the Freundlich Model fitted the data best for smaller-sized (6 x 8, 6 x 14, and 14 x 40 mesh) zeolites. Passing the CBNG water through Ca(2+)-rich zeolite columns reduced the salt content (electrical conductivity [EC]) by 72% with a concurrent reduction in sodium adsorption 10 mmol 1/2 L(-1/2). Zeolite technology appears to be an effective water treatment alternative to industrial membrane treatment for removing Na+ from poor-quality CBNG waters.

  13. Removal of arsenic species from drinking water by Iranian natural and synthetic zeolites

    International Nuclear Information System (INIS)

    Menhaje-Bena, R.; Kazemian, H.; Shahtaheri, S.J.; Ghazi-Khansari, M.

    2003-01-01

    The main objective of this study was to find a relatively inexpensive method for removal of arsenic species from drinking water. The uptake capability of Iron (II) modified natural clinoptilolites and relevant synthetic zeolites A and P was investigated toward inorganic arsenic species from drinking water. Results obtained from sorption experiments, using a batch (static) technique showed that, among the investigated zeolites, modified synthetic zeolite A was the most selective sorbent for removal of arsenate and arsenite from drinking water. Through this study the influencing of factories including temperature, concentration, pH, particle size and interferences was evaluated on removal of arsenic species. The synthetic zeolites and their modified forms were also characterized, using XRD, XRF and thermal analysis techniques. (authors)

  14. Solid phase extraction-inductively coupled plasma spectrometry for adsorption of Co(II) and Ni(II) from radioactive wastewaters by natural and modified zeolites

    International Nuclear Information System (INIS)

    Akbar Malekpour; Mohammad Edrisi; Shamsollah Shirzadi; Saeed Hajialigol

    2011-01-01

    Natural and modified clinoptilolite as low-cost adsorbents have been used for adsorption of Co(II) and Ni(II) from nuclear wastewaters both in batch and continuous experiments. Zeolite X was also synthesized and its ability towards the selected cations was examined. Kinetic and thermodynamic behaviors for the process were investigated and adsorption equilibrium was interpreted in term of Langmuir and Freundlich equations. The effect of various parameters including the initial concentration, temperature, ionic strength and pH of solution were examined to achieve the optimized conditions. The clinoptilolite was shown good sorption potential for Co(II) and Ni(II) ions at pH values 4-6. Based on desorption studies, nearly 74 and 85% of adsorbed Co(II) and Ni(II) were removed from clinoptilolite by HCl. The Na + and NH 4 + forms of clinoptilolite were the best modified forms for the removal of investigated cations. It is concluded that the selectivity of clinoptilolite is higher for Co(II) than Ni(II). The synthesized zeolite showed more ability to remove cobalt and nickel ions from aqueous solution than the natural clinoptilolite. The microwave irradiation was found to be more rapid and effective for ion exchange compared to conventional ion exchange process. (author)

  15. Effect of micronized zeolite addition to lamb concentrate feeds on ...

    African Journals Online (AJOL)

    OEM

    2016-09-21

    Sep 21, 2016 ... Natural zeolites are utilized in a number of industries such as pollution control ... the impact of zeolites on milk quality, an addition of 2.5% of clinoptilolite (zeolite) to goat feeds was demonstrated to ... triglyceride, calcium and phosphorus was carried out with spectrophotometry, and the tests for sodium,.

  16. Study of the Cd (II) removal in the presence of methyl orange with a natural zeolite conditioned with iron nanoparticles

    International Nuclear Information System (INIS)

    Xingu C, E. G.

    2015-01-01

    This work presents a study on the removal of cadmium and/or methyl-orange dye in aqueous solution, using natural zeolite clinoptilolite, as sodium homo-ionized and impregnated with iron nanoparticles. Iron nanoparticles were synthesized in the presence of the zeolite by chemical reduction. The evaluation of the removal ability was performed in a monocomponent (cadmium or methyl-orange dye) system by varying the contact time and its initial concentration. Removal capacity in a bi-component (cadmium and methyl orange) system was also studied while varying their concentrations. The characterization of the zeolites, before and after the sorption process, was carried out using several analytical techniques. The characteristics of zeolite clinoptilolite and iron particles were observed by scanning electron microscopy. The iron particles showed diameter sizes between 60 and 200 nm, localized on the surface of the zeolite. By IR spectroscopy no structural changes were detected for any of the treatments made to the zeolitic materials. By X-ray diffraction the clinoptilolite crystalline phase was mainly identified, however, it failed to detect any phase of iron in the zeolite impregnated with iron nanoparticles. Moessbauer spectroscopy indeed detected the impregnated iron phase as iron borides. The homo-ionized and iron nanoparticles impregnated zeolite showed no change in the specific surface area, or the isoelectric point, their values were 22.3 m 2 /g and ph 9.8, respectively. However, whereas the active site density for the homo-ionized zeolite was 2.87 sites/nm 2 , for iron nanoparticles impregnated zeolite was 20.32 sites/nm 2 . As a result of the analysis of the isotherms of cadmium, the maximum sorption capacity of the homo-ionized zeolite was 35.03 mg/g and for the iron nanoparticles impregnated zeolite was 36.43 mg/g. These maximum sorption capacities represent up to 85% of removed cadmium from concentrations of 50 to 600 mg/L. For the removal of methyl orange dye

  17. Na-noparticles of activated natural zeolite on textiles for protection and therapy

    Directory of Open Access Journals (Sweden)

    Ivančica Kovaček

    2009-10-01

    Full Text Available Activated natural zeolite clinoptilolite is microporous hydrated aluminosilicates crystals with well-defined structures containing AlO4 and SiO4 tetrahedral linked through the common oxygen atoms. It is to point out that zeolites act as strong adsorbents and ion-exchangers but having many other useful properties. Due to its cationexchange ability, zeolites have catalytic properties and, for that, multiple uses in medicine and industry, agriculture, water purification and detergents. Zeolites are nontoxic substance, excellent for UVR and microbes protection, for proteins and small molecules such as glucose adsorption. In this paper its positive effect on the metabolism of living organisms and its anticancerogenic, antiviral, antimetastatic and antioxidant effect. The activity of natural zeolite as natural immunostimulator was presented as well as its help in healing wounds. Therefore, the present paper is an attempt to modify cotton (by mercerization and polyester (by alkaline hydrolysis fabrics for summer clothing with addition of natural zeolite nanoparticles for achieving UV and antibacterial protective textiles

  18. Effect of zeolite (clinoptilolite as feed additive in Tunisian broilers on the total flora, meat texture and the production of omega 3 polyunsaturated fatty acid

    Directory of Open Access Journals (Sweden)

    Mallek Zouhir

    2012-03-01

    Full Text Available Abstract Background Increasing consumer demand for healthier food products has led to the development of governmental policies regarding health claims in many developed countries. In this context, contamination of poultry by food-borne pathogens is considered one of the major problems facing the progress of the poultry industry in Tunisia. Result Zeolite (Clinoptilolites was added to chicken feed at concentrations 0,5% or 1% and was evaluated for its effectiveness to reduce total flora in chickens and its effects on performance of the production. The broilers were given free and continuous access to a nutritionally non-limiting diet (in meal formthat was either a basal diet or a' zeolite diet' (the basal diet supplemented with clinoptilolite at a level of 0,5% or 1%. It was found that adding zeolite in the broiler diet significantly (p Conclusion This study showed the significance of using zeolite, as a feed additive for broilers, as part of a comprehensive program to control total flora at the broiler farm and to increase level of Omega 3 fatty acid on the chicken body.

  19. Acid Activation of Natural Zeolite with High Content of Iron Oxides in Creation of Selective Sorbents and Catalysts

    Directory of Open Access Journals (Sweden)

    Kadirbekov Kairat

    2017-01-01

    Full Text Available The paper studies the influence of the nature of modifying acids (mineral, organic and heteropolyacids, and their combination on the composition and structure of the iron oxide rich clinoptilolit from Shankanay field in Kazakhstan for creation of selective catalysts in hydracarbon processing and sorbents for extracting ions of lanthanide and actinide elements. It is shown that sequential processing of natural zeolite in optimal conditions, by hydrochloric and sulfosalicylic acids lead to intensive decationization and dealumination, as well as maximum removal of iron ions from the zeolite framework without destroying it. It is found that the combination of activated clinoptilolite with hydrochloric acid and phosphotungstic heteropolyacid contributes to obtain catalyst system with high surface area and acidity.

  20. Surface modification of a natural zeolite by treatment with cold oxygen plasma: Characterization and application in water treatment

    Science.gov (United States)

    De Velasco-Maldonado, Paola S.; Hernández-Montoya, Virginia; Montes-Morán, Miguel A.; Vázquez, Norma Aurea-Rangel; Pérez-Cruz, Ma. Ana

    2018-03-01

    In the present work the possible surface modification of natural zeolite using cold oxygen plasma was studied. The sample with and without treatment was characterized using nitrogen adsorption isotherms at -196 °C, FT-IR spectroscopy, SEM/EDX analysis and X-Ray Diffraction. Additionally, the two samples were used for the removal of lead and acid, basic, reactive and food dyes in batch systems. The natural zeolite was found to be a mesoporous material with a low specific surface area (23 m2/g). X-ray patterns confirmed that clinoptilolite was the main crystal structure present in the natural zeolite. The molecular properties of dyes and the zeolitic structure were studied using molecular simulation, with the purpose to understand the adsorption mechanism. The results pointed out that only the roughness of the clinoptilolite was affected by the plasma treatment, whereas the specific surface area, chemical functionality and crystal structure remained constant. Finally, adsorption results confirmed that the plasma treatment had no significant effects on the dyes and lead retention capacities of the natural zeolite.

  1. Ageing and structural effects on the sorption characteristics of Cd2+ by clinoptilolite and Y-type zeolite studied using isotope exchange technique

    International Nuclear Information System (INIS)

    Ahmed, I.A.M.; Young, S.D.; Crout, N.M.J.

    2010-01-01

    This research investigates the long-term kinetics of Cd 2+ sorption and desorption by calcium-exchanged clinoptilolite (CaCpt) and Y-type (CaY) zeolite using isotopic exchange with 109 Cd while maintaining pH at circumneutral values. The effects of Si/Al ratio and crystal structure of these zeolitic materials on intracrystalline transport of Cd are discussed. A first-order kinetic model was developed to describe the progressive transfer of Cd 2+ to a less reactive form within the zeolite structure, following initial sorption and subsequent desorption of Cd subject to different initial contact times. The kinetic model differentiates between two forms of sorbed Cd 2+ designated 'labile' and 'non-labile' in which the labile form is in immediate equilibrium with the free Cd 2+ ion activity in solution. A model combining diffusion and first-order kinetics for cation exchange was also employed to determine Cd 2+ diffusivity and intracrystalline exchange rates in CaY and CaCpt. The efficiency of Permeable Reactive Barriers (PRBs) containing zeolitic materials in protecting water systems against lateral flow of metal-contaminated leachate was simulated for three contrasting zeolites. The slow transfer of Cd between labile and non-labile forms was particularly important in moderating high concentration pulses of Cd traversing the PRB. In addition, the reversibility of Cd fixation effectively restored the sorption capability of the zeolite through slow leakage to drainage water.

  2. Analysis Of Natural Zeolites For Technical Nuclear

    International Nuclear Information System (INIS)

    Sarria, P.; Desdin, L.; Dominguez, O.

    1999-01-01

    In this article a methodology of elementary analysis of natural zeolites is reported using different technical nuclear (AANR, FRX, MRN and EG). Determines the elementary composition of ours of two Cuban locations. (Author) [es

  3. Comparative study of As (III) and Zn (II) removal from aqueous solutions using Philippine natural zeolite and alumina

    Science.gov (United States)

    Olegario-Sanchez, Eleanor; Pelicano, Christian Mark

    2017-12-01

    Herein, the heavy metal removal efficiency of Philippine natural zeolite is investigated through a comparative study with commercial alumina (Al2O3). XRD results revealed a high purity crystalline γ-Al2O3 and a natural zeolite having clinoptilolite (Na,K,Ca)2-3Al3(Al,Si)2Si13O36.12H2O and mordenite (Ca, Na2, K2)Al2Si10O24.7H2O as primary component minerals. Micro-pores and plate-like structures were observed on the surface of the natural zeolite. The natural zeolite has shown three times higher removal efficiency for Zn2+ ion than alumina. On the other hand, alumina exhibited comparable but smaller removal efficiency for As3+ as with that of natural zeolite. Alumina showed a higher capability of increasing the pH of both solutions compared with the natural zeolite. Based on removal efficiency and adsorbent costs, Philippine natural zeolite could be used as a low-cost alternative for wastewater treatment.

  4. Influence of Natural Zeolite on Performance of Laying Hens and Egg Quality

    OpenAIRE

    ÖZTÜRK, Ergin; ERENER, Güray; SARICA, Musa

    2014-01-01

    This experiment was conducted to study the effects of natural zeolite on the performance of laying hens. One hundred and eighty 37-week-old Babcock B-300 hens were fed with a diet containing 0, 20, 40, 60 and 80 g clinoptilolite/kg in an experiment consisting of 36 hens per treatment during a 4x28 days experimental period. All feeding programs were isocaloric and isonitrogenous. Hens were put at random into 5 treatment groups (12 replicates and 36 hens per treatment). No significant dietar...

  5. Surface modified natural zeolite as a carrier for sustained diclofenac release: A preliminary feasibility study.

    Science.gov (United States)

    de Gennaro, Bruno; Catalanotti, Lilia; Cappelletti, Piergiulio; Langella, Alessio; Mercurio, Mariano; Serri, Carla; Biondi, Marco; Mayol, Laura

    2015-06-01

    In view of zeolite potentiality as a carrier for sustained drug release, a clinoptilolite-rich rock from California (CLI_CA) was superficially modified with cetylpyridinium chloride and loaded with diclofenac sodium (DS). The obtained surface modified natural zeolites (SMNZ) were characterized by confocal scanning laser microscopy (CLSM), powder X-ray diffraction (XRPD) and laser light scattering (LS). Their flowability properties, drug adsorption and in vitro release kinetics in simulated intestinal fluid (SIF) were also investigated. CLI_CA is a Na- and K-rich clinoptilolite with a cationic exchange ability that fits well with its zeolite content (clinoptilolite=80 wt%); the external cationic exchange capacity is independent of the cationic surfactant used. LS and CLSM analyses have shown a wide distribution of volume diameters of SMNZ particles that, along with their irregular shape, make them cohesive with scarce flow properties. CLSM observation has revealed the localization of different molecules in/on SMNZ by virtue of their chemical nature. In particular, cationic and polar probes prevalently localize in SMNZ bulk, whereas anionic probes preferentially arrange themselves on SMNZ surface and the loading of a nonpolar molecule in/on SMNZ is discouraged. The adsorption rate of DS onto SMNZ was shown by different kinetic models highlighting the fact that DS adsorption is a pseudo-second order reaction and that the diffusion through the boundary layer is the rate-controlling step of the process. DS release in an ionic medium, such as SIF, can be sustained for about 5h through a mechanism prevalently governed by anionic exchange with a rapid final phase. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Ammonia removal from high salt waste water using natural zeolite; Remocao de amonia de efluentes de alta salinidade utilizando zeolita natural

    Energy Technology Data Exchange (ETDEWEB)

    Geraldo, Lucia M.L. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Arroyo, Pedro A. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas; Barros, Maria Angelica S.D.; Pazin, Elenice [Universidade Estadual de Maringa (UEM), PR (Brazil). Dept. de Quimica; Zola, Andreia S.; Zschornack, Marlon A. [Universidade Estadual de Maringa (UEM), PR (Brazil). Dept. de Quimica. Pos-Graduacao em Engenharia Quimica

    2008-07-01

    The present work aimed to study ammonium ion exchange using a fixed bed of natural zeolite clinoptilolite. First of all, it was carried out a bi component ion exchange of ammonium (150 mg/L) in the presence of K{sup +}, Ba{sup 2+}, Ca{sup 2+}, Sr{sup 2+} e Mg{sup 2+}. Thus, clinoptilolite showed a preference for strontium, barium and potassium cations, while there is a higher preference for Nh{sub 4}{sup +} cations instead calcium and magnesium. Secondly, it was studied the multicomponent ion exchange of ammonium (solution containing all cations). It was observed that the presence of competing cations decreases the content of ammonium retained in the bed until breakthrough point. Furthermore, it was also verified that multicomponent exchange in the presence of high salinity solution (60.000 mg/L of Na{sup +}), sodium influences the ion exchange mechanism, decreasing the up take capacity of ammonium for zeolitic bed. On the other hand, ammonium capture increases in the presence of natural effluent that possesses lower salinity (30.000 mg/L). Therefore, the results obtained evidence the application potentiality of clinoptilolite for ammonia up takes from industrial effluents, in what competition conditions by others cations are too severe and for that the zeolite natural presented good performance. (author)

  7. Antibacterial properties of Ag-exchanged Philippine natural zeolite-chitosan composites

    Science.gov (United States)

    Taaca, Kathrina Lois M.; Olegario, Eleanor M.; Vasquez, Magdaleno R.

    2017-12-01

    Zeolites are microporous minerals composed of silicon, aluminum and oxygen. These aluminosilicates consist of tetrahedral units which produce open framework structures to generate a system of pores and cavities of molecular dimensions. Zeolites are naturally abundant and can be mined in most parts of the world. In this study, natural zeolites (NaZ) which are locally-sourced here in the Philippines were investigated to determine its properties. An ion-exchange process was utilized, using the zeolite to silver (Ag) solution ratio of 1:20 (w/v), to incorporate Ag into the zeolite framework. Characterizations such as XRD, AAS, and Agar diffusion assay were used to evaluate the properties of the synthesized Ag-exchanged zeolites (AgZ). X-ray diffraction revealed that both NaZ and AgZ have peaks mostly corresponding to the clinoptilolite structure, with some trace peaks of the mordenite and quartz. Absorption spectroscopy revealed that the ion exchange process added about 0.61188g of silver into the zeolite structure. This Ag content was seen to be enough to make the AgZ sample exhibit an antibacterial effect where clearing zones against E. coli and S. aureus were observed in the agar diffusion assay, respectively. The AgZ sample was also tested as ceramic filler to a polymer matrix-chitosan. The diffusion assay revealed presence of antibacterial activity to the polymer composite with AgZ fillers. These results indicate that the Philippine natural zeolite, incorporated with metals such as Ag, can be used as an antibacterial agent and can be developed as a ceramic filler to improve the antibacterial property of composite materials for biomedical application.

  8. Removal Of Copper From Aqueous Solutions By Using Natural And Fe-Modified Clinoptilolite

    Directory of Open Access Journals (Sweden)

    Lipovský Marek

    2015-06-01

    Full Text Available Removal of copper from aqueous solution on the natural and modified clinoptilolite was studied under static conditions. Batch adsorptions of copper were performed to investigate the effects of contact time and initial metal ion concentration. The Freundlich and Langmuir adsorption isotherms were used to analyse the experimental data. The kinetic analyses of the adsorption processes were performed using the pseudo-first-order and pseudo-second-order kinetic models.

  9. Removal of cadmium in urban wastewater with systems based on zeolite type clinoptilolite; Remocion de cadmio en aguas residuales urbanas con sistemas a base de zeolita tipo clinoptilolita

    Energy Technology Data Exchange (ETDEWEB)

    Barragan P, P.

    2016-07-01

    From an environmental issue detected in wastewater samples taken in a municipal wastewater collector in Nogales, Sonora, which is related to cadmium pollution, a research project came out where the principal aim was to implement a system to remove metallic ions of cadmium in wastewater, based on modified and unmodified natural zeolites. The zeolitic material used was natural clinoptilolite modified with NaCl and thiourea, sourced in El Cajon and Guaymas, Sonora. The materials were characterized with X-ray diffraction, Sem, Ft-IR spectra, and Bet analysis. The kinetics of four modified zeolites was investigated at ph=5 and initial concentration of 30 mgL{sup -1} of Cd{sup 2+}. The pseudo-first, the pseudo-second order, and Elovich models were applied to the experimental results. The results best fitted to pseudo-second order model. The maximum sorption capacity of modified zeolites was investigated through isotherms, The Langmuir model, Freundlich, and the combined Langmuir-Freundlich models were applied to the experimental results afterwards. ZGuayThio showed the highest sorption capacity, 11.60 mgg{sup -1}, with R{sup 2}=0.978 according to Langmuir-Freundlich model. Fixed-bed column adsorption experiments were carried out with ZGuayNa and ZGuayThio with three bed heights with 30 mgL{sup -1} solution of Cd{sup 2+}. influent at a flow rate of 1 mLmin{sup -1}, at ph=5. The Thomas, mass balance, and Bed Depth Service Time models were applied to the results. The dynamic adsorption capacity (No) and the constant of sorption velocity (K a) were determined, 28.67 gL{sup -1} and 0.072 Lg{sup -1}min{sup -1} respectively for ZGuayNa with R{sup 2}= 0.9954. Column experiments with municipal wastewater from Colinas del Yaqui sub-collector, previously characterized, were conducted using ZGuayNa and ZGuayThio. A mass transference model was applied to the results which accounted for K{sub p}= 0.815 m{sup 3}Kg{sup -}1 with R{sup 2}= 0.9789 for ZGuayNa, and K{sub p}= 3.1 m{sup 3}Kg

  10. Thermal Transformation of NH4-Clinoptilolite to Mullite and Silica Polymorphs

    Directory of Open Access Journals (Sweden)

    Antonio Brundu

    2017-01-01

    Full Text Available Clinoptilolite is a natural zeolite used for the abatement of ammonium in the treatment of urban wastewater. By considering that mullite was obtained through thermal treatment of NH4-exchanged synthetic zeolites, this work aimed to evaluate if this phase can be obtained from NH4-clinoptilolite. A material containing about 90 wt % of clinoptilolite, prepared using a Sardinian zeolite-rich rock, was NH4-exchanged and subjected to treatments up to 1200 °C. After dehydration, de-ammoniation, and dehydroxylation processes, the clinoptilolite structure collapsed at 600 °C. An association of mullite, silica polymorphs, and glass, whitish in color, was obtained for treatments between 1000 and 1200 °C. The higher degree of crystallinity was reached after a 32 h heating at 1100 °C: mullite 22 wt %, cristobalite 59 wt %, tridymite 10 wt %, glass 9 wt %. It is possible to speed up the kinetics of the transformation by increasing the temperature to 1200 °C, obtaining the same amount of mullite in 2 h, but increasing the residual amorphous fraction (16 wt %. These results indicate that NH4-clinoptilolite could represent a raw material of potential interest in the ceramic field, in particular in the production of acid refractory, opening scenarios for a possible reuse of clinoptilolite-based exchangers employed in ammonium decontamination.

  11. Cupric natural zeolites as microbic ides

    International Nuclear Information System (INIS)

    Contreras A, D.; Olguin G, M. T.; Alcantara D, D.; Burrola A, C.

    2009-01-01

    The Escherichia coli and the Candida albicans are considered contamination indicators for what these organisms reflect the water quality. The natural zeolites by their characteristics and properties, they could incorporate to a waters treatment system, as ion exchange, adsorbents and/or microbiocid agents, representing an alternative method of low cost. Inside this investigation work was found that depending on the microorganism type, it varies the quantity of cupric zeolite that is required to carry out the water disinfection, being great for the case of yeasts than the bacteria s. In addition to that marked differences are presented in the required time to reach this process. The characterization of the natural zeolite material, sodium and cupric, was realized by means of scanning electron microscopy, determining the elementary composition (Energy Dispersive Spectroscopy) of each one of them, and by X-ray diffraction. (Author)

  12. Clinoptilolite in Drinking Water Treatment for Ammonia Removal

    Directory of Open Access Journals (Sweden)

    H. M. Abd El-Hady

    2001-01-01

    Full Text Available In most countries today the removal of ammonium ions from drinking water has become almost a necessity. The natural zeolite clinoptiloliteis mined commercially in many parts of the world. It is a selective exchanger for the ammonium cation, and this has prompted its use in water treatment, wastewater treatment, swimming pools and fish farming. The work described in this paper provides dynamic data on cation exchange processes in clinoptilolite involving the NH4 +, Ca+2 and Mg+2 cations. We used material of natural origin – clinoptilolite from Nižný Hrabovec in Slovakia (particle-size 3–5 mm. The breakthrough capacity was determined by dynamic laboratory investigations, and we investigated the influence of thermal pretreatment of clinoptilolite and the concentration of regenerant solution (2, 5, and 10% NaCl. The concentrations of ammonium ion inputs in the tap water that we used were 10, 5, and 2 mg NH4 + l_1 and down to levels below 0.5 mg NH4 + l_1. The experimental results show that repeated pretreatment sufficiently improves the zeolite’s properties, and the structure of clinoptilolite remains unchanged during the loading and regeneration cycles. Ammonium removal capacities were increased by approximately 40 % and 20 % for heat-treated zeolite samples. There was no difference between the regenerates for 10% and 5% NaCl. We conclude that the use of zeolite is an attractive and promising method for ammonium removal.

  13. THE PREPARATION OF MAGNETICALLY MODIFIED SYNTHETETIC AND NATURAL ZEOLITES AND COMPARISON OF THEIR SOME PHYSICAL PROPERTIES

    Directory of Open Access Journals (Sweden)

    Zafer DİKMEN

    2013-06-01

    Full Text Available In this study, magnetically modified zeolites (MMZ has been produced and their adsorption, ion-exchange and magnetic properties have been studied. In this study, natural zeolite mineral, clinoptilolite, which belongs to Gördes (Manisa regions and synthetic 13X zeolite, which has been produced by Sigma-Aldrich firm have been used. In order to modify the surface of these minerals, magnetite sample which belongs to Divriği (Sivas region has been used. The engagement of magnetite particles on zeolite particles has been studied. For this reason, measuring, visualization and analysis techniques as DTA-TG, XRD, XRF, SEM and EDX have been used. As a result of these procedures, it has been observed that magnetite particles get engaged on the surface of zeolite particles and magnetite contribu-tion on MMZ has changed adsorption, ion-exchange and magnetic properties.In order to determine how magnetite contribution affects adsorption, ion exchange and magnetic properties of MMZ, weightily magnetite contribution ratio (zeolite/magnetite has been applied in three different forms (1/1, 1/2, 1/3.As a result of nitrogen adsorption of MMZ, it has been observed that as the weightily magnetite contribution ratio goes up, specific surface area goes down and average pore diameter rises. It has been identified that total cation exchange capacity rises as the weightily magnetite contribution ratio goes up. It has been observed that pure zeolites, which have no magnetic properties, as a result of magnetically modification process, they have got magnetically character, and they change their magnetic properties positively as the weightily magnetite contribution goes up. It has been determined that as a result of magnetic measurements; the optimum value of applied outer magnetic field is 0.5T.

  14. Effect of the modification of a natural mexican zeolite in the sorption of cadmium and 4-chloro phenol

    International Nuclear Information System (INIS)

    Cortes M, R.

    2007-01-01

    Clinoptilolite type zeolite is a material of relative abundance in Mexico, which possess ion exchange properties and it can be used in the removal of metal ions from polluted waters. The external surface of zeolites can be modified with cationic surfactants. This modification could have a negative effect on the removal of metal ions and provides to the material the capacity to adsorb phenolic compounds. For this reason, it is important to know the capability of the modified material on the sorption of metal ions and phenolic compounds, simultaneously. The aim of this work was to evaluate the effect of the external surface modification with surfactant of a Mexican zeolite over its sorption capacity of cadmium and 4-chloro phenol, in batch and column systems. To accomplish that, a clinoptilolite type zeolitic rock from a deposit located in the state of Sonora, Mexico, was used. It was ground, sieved and characterized with different techniques; and its external surface area was modified with hexadecyltrimethylammonium bromide (HDTMA-Br). A grain size fraction was selected to carry out sorption kinetics and equilibrium experiments, as well as packed column tests with zeolitic material and solutions of cadmium and 4-chloro phenol. There are different models proposed in literature that are used to describe sorption kinetics and equilibrium. In this work, the sorption experimental results were adjusted to some of these models to identify controlling mechanisms on the kinetics and equilibrium of the studied systems. The results showed that the cadmium adsorption on natural and modified zeolite was similar in batch systems. For the case of 4-chloro phenol sorption, it was observed that natural zeolite does not retain this compound, while in modified zeolite the sorption is better than other comparable materials. The results also showed that for the case of cadmium sorption, the mechanism involved was ion exchange; while for sorption of 4-chloro phenol, a partition mechanism

  15. Study of Methylene Blue Degradation by Gold Nanoparticles Synthesized within Natural Zeolites

    Directory of Open Access Journals (Sweden)

    Ericka Rodríguez León

    2016-01-01

    Full Text Available We carried out the in situ synthesis of gold nanoparticles inside a natural clinoptilolite-type zeolite matrix, using ascorbic acid as reducing agent. The microstructure of both zeolite and zeolite-gold nanocomposite was characterized by X-ray diffraction (XRD, Scanning Electron Microscopy (SEM, Scanning Transmission Electron Microscopy (STEM, and Energy-Dispersive X-ray Spectroscopy (EDS techniques. Size distribution as assessed by STEM indicated that 60% of gold nanoparticles measured less than 2.5 nm. Determination of the surface area by the BET method revealed a specific value of 27.35 m2/g. The catalytic activity of zeolite-gold regarding methylene blue degradation under different light-exposing conditions was evaluated by UV-Vis spectroscopy. The results indicated that 50% degradation was achieved in only 11 min in presence of sunlight. This reaction was faster in comparison with those obtained using a white LED light. A notable aspect of this study is that catalysis was carried out without the addition of any strong reducing agents, such as sodium borohydride (NaBH4.

  16. An integrated remediation system using synthetic and natural zeolites for treatment of wastewater and contaminated sediments

    International Nuclear Information System (INIS)

    Rios Reyes, Carlos; Appasamy, Danen; Clive, Roberts

    2011-01-01

    The major sources of water pollution can be classified as municipal, industrial, and agricultural. Different types of polluted aqueous effluents and sediments may be produced, which contain relatively high levels of heavy metals. During the 1990s, the large-scale development of constructed wetlands around the world drew much attention from public and environmental groups. The present study looks at the use of an integrated remediation system using zeolites for the treatment of wastewater and sediments. Zeolites have been widely studied in the past 10 years due to their attractive properties such as molecular-sieving, high cation exchange capacities, and their affinity for heavy metals. Coal industry by-products-based zeolites (faujasite type) have been tested as an effective and low-cost novel alternative for wastewater treatment, particularly their removing of heavy metals. On the other hand, a preliminary laboratory-scale experiment was conducted on the use of natural zeolites (clinoptilolite type) for the retention of heavy metals from canal sediments. Experimental work revealed promising results, which could be replicated on a bigger scale. Although this has been developed for canal sediments, the remediation strategy can be adapted to different waterways such as rivers. The development of the proposed remediation system in a specific experimental site as the major part of an innovation park can provide great benefits to a population living near contaminated effluents. It provides not only opportunities for the mitigation of environmental impact, improving water quality and landscape amenity, but also allows for several recreational opportunities

  17. Effect of the temperature on the sorption of cadmium in natural clinoptilolite from the State of Chihuahua; Efecto de la temperatura sobre la sorcion de cadmio en clinoptilolita natural del Estado de Chihuahua

    Energy Technology Data Exchange (ETDEWEB)

    Arambula V, V

    2004-07-01

    The investigation works related with the removal of cadmium of aqueous solutions, they make emphasis in a great number of materials that were used for this end, as well as in the parameters that influence, such as the temperature and the pH. In this work it was investigated the effect of the temperature on the removal of cadmium, using a zeolitic mineral native of the State of Chihuahua for they were determined it kinetic parameters, those diffusivity coefficients and the retention mechanisms (adsorption or ion exchange) involved. The clinoptilolite samples were characterized by means of scanning electron microscopy in high vacuum (MEB), elementary microanalysis (EDS) and X-ray diffraction (XRD). The experimental part consisted on putting in contact solutions of cadmium with the mineral, varying the temperature, the time of contact or the concentration; the quantification of sodium and cadmium in the liquid phase was carried out by means of atomic absorption spectroscopy (EAA). It was determined the time of equilibrium for the removal process. The temperature and the concentration influence on the process of sorption of cadmium in the zeolitic mineral (kinetics and isotherms). The kinetic model that describes better the sorption process of cadmium in the clinoptilolite was the pseudo-2 order. The apparent coefficient of diffusivity presented a greater value conforms to increment the temperature. The results of the isotherm of adsorption of cadmium presented a better adjustment to the Freundlich model. The quantity of cadmium retained by the mineral it was greater than the quantity of sodium found in the solution after the contact between the solution of cadmium and the zeolitic mineral and in accordance with the obtained separation factors, the natural zeolite shows a greater affinity for the cadmium that for the sodium ({alpha} > 1). (Author)

  18. Characterization of Mexican zeolite minerals

    International Nuclear Information System (INIS)

    Jimenez C, M.J.

    2005-01-01

    50% of the Mexican territory is formed by volcanic sequences of the Pliocene type, which appear extensively in the northwest states (Sonora, Sinaloa, Chihuahua, Durango) and west of Mexico (Jalisco and Nayarit), in central Mexico (Zacatecas, Guanajuato, San Luis Potosi, Queretaro, Hidalgo) and south of Mexico (Guerrero, Oaxaca); therefore, it is to be expected that in our country big locations of natural zeolites exist in its majority of the clinoptilolite type. The present study was focused toward the characterization of two Mexican natural zeolite rocks presumably of the clinoptilolite and filipsite types, one of them comes from the state of Chihuahua and the other of a trader company of non metallic minerals, due that these materials are not characterized, its are not known their properties completely and therefore, the uses that can be given to these materials. In this investigation work it was carried out the characterization of two Mexican zeolite rocks, one coming from the Arroyo zone, municipality of La Haciendita, in the state of Chihuahua; and the other one was bought to a trader company of non metallic minerals. The two zeolites so much in their natural form as conditioned with sodium; they were characterized by means of X-ray diffraction, scanning electron microscopy of high vacuum and elementary microanalysis (EDS), surface area analysis (BET), thermal gravimetric analysis. To differentiate the heulandite crystalline phase of the other clinoptilolite rock, its were carried out thermal treatments. The quantification of Al, Na, Ca, K, Mg, Fe was carried out in solution, by means of atomic absorption spectroscopy and the quantity of Si was determined by gravimetry. The zeolite rocks presented for the major part the crystalline heulandite and clinoptilolite phases for the most part, and it was found that the zeolite coming from the state of Chihuahua possesses a bigger content of heulandite and the denominated filipsite it is really a zeolite

  19. Environmental application of russian natural zeolites

    International Nuclear Information System (INIS)

    Fursenko, B.

    1998-01-01

    There are more than 70 deposits and localities of zeolite-containing rocks (ZCR) in Russia. Total resources of relatively rich (more than 40% of zeolites) rocks are estimated as 3.8 billion tons. The main Russian deposits are located in Siberia and Far East. A number of traditional ways of ZCR utilization for environmental protection have been developed in Russia during last two decades, when a few governmental scientific programs were in operation. These were: (1) waste water treatment (galvanic waste, oil-product pollution, municipal waste water, radioactive pollution); (2) drinking water preparation (municipal and individual filters, coagulation method, lemonade production); (3) gas drying and purification (natural gas drying, stack-gas cleanup, oxygen enriched air production). Growing interest was attracted to zeolites due to their potential utilization in the nuclear waste treatment, re-cultivation of technically polluted territories and especially after they were used for localization of the radioactive accidents on the atomic power stations (Three Mile Island, U.S.A. in 1981 and Chernobyl, USSR in 1986). Structure, ion-exchange capacity and phase transformations of the zeolites are discussed

  20. The comparison of the structures of some cationic forms of clinoptilolite obtained from Manisa-Gordes in Turkey using their XRD spectrums

    International Nuclear Information System (INIS)

    Izci, E.; Orhun, O.

    2000-01-01

    In this study, at room temperature, XRD spectrums of Na, Ca, Li, Pb and natural forms of clinoptilolite, which is a natural zeolite obtained from Manisa-Gordes in Turkey, were taken and compared with each other according to their structures. Firstly, clinoptilolite samples, whose, diameters are smaller than 63 μm, were purified by HCl. Thus, impurities through the channels of clinoptilolite samples, were removed from their structures. Then, the samples washed several times by deionised water and filtered. So, HCl was removed from structures of these samples. Na, Ca, Li, Pb ionic forms of clinoptilolite were prepared by using batch method. XRD apparatus from Rigaku-Rint 2000 series. Comparing of XRD spectrums of these ionic and natural forms of clinoptilolite and finding the variations of their spectrums, what changes in their structures could be, were investigated. (authors)

  1. Natural zeolite polypropylene composite film preparation and characterization

    OpenAIRE

    Özmıhçı, Filiz; Balköse, Devrim; Ülkü, Semra

    2001-01-01

    In this research, the preparation and characterization of polypropylene (PP) and natural zeolite composites were studied. Natural zeolite mined in Gördes, Turkey was used as an alternative filler to CaCO3. Films were prepared by the extrusion of PP, and surface-modified zeolite was made by polyethylene glycol 4000 with 2-4% zeolite. Zeolite-filled composites had densities between 0.73 and 0.83 g/cm3 and had void fractions of 0.07-0.20. Although the permeability of water vapour through 2% zeol...

  2. Obtaining of iron particles of nanometer size in a natural zeolite

    International Nuclear Information System (INIS)

    Xingu C, E. G.

    2013-01-01

    The zeolites are aluminosilicates with cavities that can act as molecular sieve. Their crystalline structure is formed by tetrahedrons that get together giving place to a three-dimensional net, in which each oxygen is shared by two silicon atoms, being this way part of the tecto silicate minerals, its external and internal areas reach the hundred square meters for gram, they are located in a natural way in a large part of earth crust and also exist in a synthetic way. In Mexico there are different locations of zeolitic material whose important component is the clinoptilolite. In this work the results of three zeolitic materials coming from San Luis Potosi are shown, the samples were milled and sieved for its initial characterization, to know its chemical composition, crystalline phases, morphology, topology and thermal behavior before and after its homo-ionization with sodium chloride, its use as support of iron particles of nanometer size. The description of the synthesis of iron particles of nanometer size is also presented, as well as the comparison with the particles of nanometer size synthesized without support after its characterization. The characterization techniques used during the experimental work were: Scanning electron microscopy, X-ray diffraction, Infrared spectroscopy, specific area by means of BET and thermogravimetry analysis. (Author)

  3. Hierarchical porous structured zeolite composite for removal of ionic contaminants from waste streams and effective encapsulation of hazardous waste

    Energy Technology Data Exchange (ETDEWEB)

    Al-Jubouri, Sama M. [Chemical Engineering & Analytical Science, The University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Curry, Nicholas A. [Materials Science, The University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Holmes, Stuart M., E-mail: stuart.holmes@manchester.ac.uk [Chemical Engineering & Analytical Science, The University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom)

    2016-12-15

    A hierarchical structured composite made from clinoptilolite supported on date stones carbon is synthesized using two techniques. The composites are manufactured by fixing a natural zeolite (clinoptilolite) to the porous surface of date stones carbon or by direct hydrothermal synthesis on to the surface to provide a supported high surface area ion-exchange material for metal ion removal from aqueous streams. The fixing of the clinoptilolite is achieved using sucrose and citric acid as a binder. The composites and pure clinoptilolite were compared to test the efficacy for the removal of Sr{sup 2+} ions from an aqueous phase. The encapsulation of the Sr{sup 2+} using either vitrification or a geo-polymer addition was tested to ensure that the hazardous waste can be made safe for disposal. The hierarchical structured composites were shown to achieve a higher ion exchange capacity per gram of zeolite than the pure clinoptilolite (65 mg/g for the pure natural clinoptilolite and 72 mg/g for the pure synthesized clinoptilolite) with the synthesized composite (160 mg/g) having higher capacity than the natural clinoptilolite composite (95 mg/g). The rate at which the equilibria were established followed the same trend showing the composite structure facilitates diffusion to the ion-exchange sites in the zeolite.

  4. Dietary effects of Ca-zeolite supplementation on some blood and ...

    African Journals Online (AJOL)

    This study was conducted to investigate the effects of differing amounts of natural Ca-zeolite on bone and some blood parameters. A total of 240 day-old Ross 308 broiler chicks were assigned to four treatments with three replicates, each containing 20 day-old chicks of mixed sex. A clinoptilolite+mordenite type of zeolite ...

  5. Analysis for the Sorption Kinetics of Ag Nanoparticles on Natural Clinoptilolite

    Directory of Open Access Journals (Sweden)

    Alvaro Ruíz-Baltazar

    2015-01-01

    Full Text Available The kinetic adsorption behavior of silver nanoparticles deposited on a natural zeolite from Oaxaca is presented. Theoretical models as Lagergren first-order, pseudo-second-order, Elovich, and intraparticle diffusion were employed and compared with experimental data obtained by atomic absorption spectrophotometry technique. Correlation factors R2 of the order of 0.99 were observed. Analysis by transmission electron microscopy revealed that the silver nanoparticles were homogeneously distributed on the zeolite. Additionally, chemical characterization of the material was carried out through a dilution process with lithium metaborate. An average value of 9.3 in the Si/Al ratio was observed and related to the kinetic adsorption behavior of the zeolite.

  6. Uptake of Sulfadiazine Sulfonamide from Water by Clinoptilolite

    Directory of Open Access Journals (Sweden)

    Zhaohui Li

    2013-01-01

    Full Text Available The interactions between sulfadiazine (SDZ, a sulfonamide antibiotic, and clinoptilolite, a hydrophilic zeolite, were investigated under batch experimental conditions. The uptake of SDZ on the zeolite followed a linear sorption isotherm under neutral pH conditions. Higher SDZ uptake on the zeolite was observed when solution pH was below the or above the values of SDZ, while minimal SDZ uptake was observed when the solution pH was between the and values of SDZ. These observations suggested that hydrophobic interaction between SDZ and the zeolite was minimal due to the hydrophilic nature of the substrate. Electrostatic interactions and ion bridging were attributed to the elevated SDZ uptake under low and high pH conditions. As SDZ had a low value, the hydrophilic nature of the substrate prevented extensive uptake of SDZ, which could contribute to its extensive detection in the environment, including surface water and wastewater.

  7. Adsorption of ions onto treated natural zeolite

    Directory of Open Access Journals (Sweden)

    Cristiane da Rosa Oliveira

    2007-12-01

    Full Text Available This work presents studies of modification of a natural zeolite by activation with Na+ cations and functionalisation with Ba+2 and/or Cu2+ ions (FZ. The zeolite was characterized, modified and applied in adsorption studies of sulphate and isopropilxanthate ions as flocculated and powdered forms. The reuse of SO4Ba-FZ was investigated by adsorption-removal of either Ba2+ or sulphate ions in stages. Equilibrium data showed that the FZ, flocculated or as powder, provide considerable removal of sulphate ions (q mLangmuir: 1.15 and 1.35 meq.g-1, respectively and isopropilxanthate (q mLangmuir: 0.35 and 0.93 meq.g-1, respectively. The reuse of the SO4-FZ, either powdered or flocculated also uptake significant amount of Ba2+ or sulphate ions (q mLangmuir: 1.15 meq.g-1, providing a new alternative for the exhausted adsorbent. Thus the activated and functionalised zeolites create new options on the materials engineering area with applications in environmental applied adsorption processes.

  8. Use of Natural Zeolite to Upgrade Activated Sludge Process

    Directory of Open Access Journals (Sweden)

    Hanife Büyükgüngör

    2003-01-01

    Full Text Available The objective of this study was to achieve better efficiency of phosphorus removal in an enhanced biological phosphorus removal process by upgrading the system with different amounts of natural zeolite addition. The system performance for synthetic wastewater containing different carbon sources applied at different initial concentrations of phosphorus, as well as for municipal wastewater, was investigated. Natural zeolite addition in the aerobic phase of the anaerobic/aerobic bioaugmented activated sludge system contributed to a significant improvement of phosphorus removal in systems with synthetic wastewater and fresh municipal wastewater. Improvement of phosphorus removal with regard to the control reactors was higher with the addition of 15 than with 5 g/L of natural zeolite. In reactors with natural zeolite addition with regard to the control reactors significantly decreased chemical oxygen demand, ammonium and nitrate, while higher increment and better-activated sludge settling were achieved, without changes in the pH-values of the medium. It was shown that the natural zeolite particles are suitable support material for the phosphate-accumulating bacteria Acinetobacter calcoaceticus (DSM 1532, which were adsorbed on the particle surface, resulting in increased biological activity of the system. The process of phosphorus removal in a system with bioaugmented activated sludge and natural zeolite addition consisted of: metabolic activity of activated sludge, phosphorus uptake by phosphate-accumulating bacteria adsorbed on the natural zeolite particles and suspended in solution, and phosphorus adsorption on the natural zeolite particles.

  9. Treatments of reverse osmosis concentrate using natural zeolites

    OpenAIRE

    Taherifar Hossein; Rezvantalab Sima; Bahadori Fatemeh; Khoei Omid Sadrzadeh

    2015-01-01

    The purpose of the current study is to experimentally investigate the reduction of sodium adsorption ratio (SAR) from a concentrated stream of reversed osmosis (RO) using natural zeolites. In order to reduce the salinity of solution, experiments were carried out using zeolites of varying concentration, pretreatment of adsorbents, and the addition of Ethylenediaminetetraacetic acid (EDTA). The results show that both zeolites can be used in an RO brine treatment; however, Rhyolitic tuff is more...

  10. Structure modification of natural zeolite for waste removal application

    Science.gov (United States)

    Widayatno, W. B.

    2018-03-01

    Tremendous industrialization in the last century has led to the generation of huge amount of waste. One of the recent hot research topics is utilizing any advance materials and methods for waste removal. Natural zeolite as an inexpensive porous material with a high abundance holds a key for efficient waste removal owing to its high surface area. However, the microporous structure of natural zeolite hinders the adsorption of waste with a bigger molecular size. In addition, the recovery of natural zeolite after waste adsorption into its pores should also be considered for continuous utilization of this material. In this study, the porosity of natural zeolite from Tasikmalaya, Indonesia, was hydrothermally-modified in a Teflon-lined autoclave filled with certain pore directing agent such as distilled water, KOH, and NH4OH to obtain hierarchical pore structure. After proper drying process, the as-treated natural zeolite is impregnated with iron cation and heat-treated at specified temperature to get Fe-embedded zeolite structure. XRD observation is carried out to ensure the formation of magnetic phase within the zeolite pores. The analysis results show the formation of maghemite phase (γ-Fe2O3) within the zeolite pore structure.

  11. Methylene blue removal from contaminated waters using O3, natural zeolite, and O3/zeolite.

    Science.gov (United States)

    Valdés, H; Tardón, R F; Zaror, C A

    2009-01-01

    This paper compares experimental results on methylene blue (MB) removal systems based on ozone oxidation, zeolite adsorption, and simultaneous adsorption-oxidation using ozone in the presence of natural zeolite. The effect of pH (2-8), and the presence of radical scavengers (sodium acetate) on process rates and removal efficiencies are assessed at laboratory scale. The experimental system consisted of a 1 L differential circular flow reactor and an ozone generator rated at 5 g O3/h. Results show that ozone oxidation combined with zeolite adsorption increases the overall MB oxidation rate with respect to ozonation process and zeolite adsorption. In presence of free radical scavenger, only a 25% of reduction on MB removal rate are observed in the simultaneous treatment, as compared with 70% when ozonation treatment is used, suggesting that MB oxidation reactions take mainly place on the zeolite surface.

  12. Hydrogen Separation by Natural Zeolite Composite Membranes: Single and Multicomponent Gas Transport

    Directory of Open Access Journals (Sweden)

    Afrooz Farjoo

    2017-10-01

    Full Text Available Single and multicomponent gas permeation tests were used to evaluate the performance of metal-supported clinoptilolite membranes. The efficiency of hydrogen separation from lower hydrocarbons (methane, ethane, and ethylene was studied within the temperature and pressure ranges of 25–600 °C and 110–160 kPa, respectively. The hydrogen separation factor was found to reduce noticeably in the gas mixture compared with single gas experiments at 25 °C. The difference between the single and multicomponent gas results decreased as the temperature increased to higher than 300 °C, which is when the competitive adsorption–diffusion mechanism was replaced by Knudsen diffusion or activated diffusion mechanisms. To evaluate the effect of gas adsorption, the zeolite surface isotherms of each gas in the mixture were obtained from 25 °C to 600 °C. The results indicated negligible adsorption of individual gases at temperatures higher than 300 °C. Increasing the feed pressure resulted in a higher separation efficiency for the individual gases compared with the multicomponent mixture, due to the governing effect of the adsorptive mechanism. This study provides valuable insight into the application of natural zeolites for the separation of hydrogen from a mixture of hydrocarbons.

  13. ETHIOPIAN NATURAL ZEOLITES FOR PHOTOCATALYSIS Kiros ...

    African Journals Online (AJOL)

    B. S. Chandravanshi

    This sample, called ET4, contains other non-zeolitic phases like celadonite and ilmenite, which may synergize the potential application of this high Ti- containingsample for photocatalysis. EXPERIMENTAL. Sample preparation. Three different approaches were carried out: i) simple calcination of raw zeolite ET4 sample: 1.

  14. Recovery of ammonia from domestic wastewater effluents as liquid fertilizers by integration of natural zeolites and hollow fibre membrane contactors.

    Science.gov (United States)

    Sancho, I; Licon, E; Valderrama, C; de Arespacochaga, N; López-Palau, S; Cortina, J L

    2017-04-15

    The integration of up-concentration processes to increase the efficiency of primary sedimentation, as a solution to achieve energy neutral wastewater treatment plants, requires further post-treatment due to the missing ammonium removal stage. This study evaluated the use of zeolites as a post-treatment step, an alternative to the biological removal process. A natural granular clinoptilolite zeolite was evaluated as a sorbent media to remove low levels (up to 100mg-N/L) of ammonium from treated wastewater using batch and fixed bed columns. After being activated to the Na-form (Z-Na), the granular zeolite shown an ammonium exchange capacity of 29±0.8mgN-NH 4 + /g in single ammonium solutions and 23±0.8mgN-NH 4 + /g in treated wastewater simulating up-concentration effluent at pH=8. The equilibrium removal data were well described by the Langmuir isotherm. The ammonium adsorption into zeolites is a very fast process when compared with polymeric materials (zeolite particle diffusion coefficient around 3×10 -12 m 2 /s). Column experiments with solutions containing 100mgN-NH 4 + /L provide effective sorption and elution rates with concentration factors between 20 and 30 in consecutive operation cycles. The loaded zeolite was regenerated using 2g NaOH/L solution and the rich ammonium/ammonia concentrates 2-3g/L in NaOH were used in a liquid-liquid membrane contactor system in a closed-loop configuration with nitric and phosphoric acid as stripping solutions. The ammonia recovery ratio exceeded 98%. Ammonia nitrate and di-ammonium phosphate concentrated solutions reached up to 2-5% wt. of N. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Nanomodified natural zeolite as a fertilizer of prolonged activity

    Directory of Open Access Journals (Sweden)

    G. Tsintskaladze

    2016-09-01

    Full Text Available Natural zeolites of sedimentary origin are widely used in agriculture both as individual fertilizer and a mix of mineral and organic fertilizers. Natural zeolites are crystalline nanoporous hydrated aluminosilicates. Fertilizer of prolonged activity enriched with macro- and microelements is obtained by fusing zeolite with dehydrated ammonium using nanotechnological method of modification. The structure and some physical and chemical properties of a novel nanomaterial were studied by the methods of X-ray diffraction, IR-spectroscopy, absorption and thermal analysis. It was shown that the obtained fertilizer may be used in both protected and open grounds.

  16. Radiotracer study of the adsorption of Fe(III), Cr(III) and Cd(II) on natural and chemically modified Slovak zeolite

    International Nuclear Information System (INIS)

    Foeldesova, M.; Dillinger, P.; Lukac, P.

    1998-01-01

    In order to minimize the contamination of environment with metals in ionic form the more types of natural and chemically modified zeolites were examined to their uptake of Fe(III), Cr(III) and Cd(II) from water solutions by batch radio-exchange equilibration method. In this study was used zeolitic tuff from deposit Nizny Hrabovec (content of clinoptilolite 50-70%) with the grain size from 1.2 to 2.2 mm. The granules of zeolite were modified with the following NaOH solutions: ).5, 1, 2 and 4 mol.l -1 at 80 grad C for 4 hours. The sorption of Fe, Cr and Cd ions on all types of zeolites was studied by radio-exchange method and the sorption of Fe and Cr also flame atomic absorption method. From sorption curves the sorption coefficients were calculated. The results obtained in this work show that zeolites modified with NaOH solution are suitable for adsorption of Fe(III), Cr(III) and Cd(II) from underwater, waste water, feed water and coolant water from nuclear plants. The adsorbed zeolites can be solidified by conventional way

  17. Effect of the humic acids in the adsorption of U (Vi) in a Mexican natural zeolite; Efecto de los acidos humicos en la adsorcion de U (VI) en una zeolita natural mexicana

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval G, H. A.; Lopez del R, H.; Davila R, J. I.; Mireles G, F., E-mail: hlopezdelrio@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2012-10-15

    The uranium adsorption was studied in a Mexican natural zeolite of the clinoptilolite type in presence and absence of humic acids (Ha). The adsorption kinetics of the binary U-zeolite and ternary U-Ha-zeolite systems were compared, and the effect of the humic matter impregnated in the zeolite in the uranium removal in function of the solution ph was studied. The experiments were made to environmental conditions and lightly acid ph, with fixed concentrations of uranium and Ha of 1 x 10{sup -5} M and 20 ppm, respectively, and a reason m/V of 5 mg/ml. The uranium adsorption in absence of Ha was of 96% and decreased to 45% in the ternary system U-Ha-zeolite. The data of the binary system U-zeolite were analyzed with three kinetic models of adsorption (pseudo-first order, pseudo-second order and Elovich). By means of non lineal regression was found that the uranium adsorption obeys a kinetic of pseudo-second order. It was observed that the uranium adsorption in the zeolite impregnated with Ha is favored to more ph at 5. (Author)

  18. Ammoniacal nitrogen removal from groundwaters using natural and synthetic zeolites

    OpenAIRE

    Matsiyevska, Oksana; Chverenchuk, Andrii; Soprunko, Svitlana; Berezyuk, Roman; Pidlisny, Bogdan

    2013-01-01

    In article results of ammoniacal nitrogen occurrence ways into groundwaters analysis was represented. NH4+ removing effectivity from simulative solutions by natural (Sokyrnytsia minefield, Ukraine) and synthetic zeolites was compared.

  19. Study of the Cd (II) removal in the presence of methyl orange with a natural zeolite conditioned with iron nanoparticles; Estudio de la remocion de Cd(II) en presencia de naranja de metilo con una zeolita natural acondicionada con nanoparticulas de hierro

    Energy Technology Data Exchange (ETDEWEB)

    Xingu C, E. G.

    2015-07-01

    This work presents a study on the removal of cadmium and/or methyl-orange dye in aqueous solution, using natural zeolite clinoptilolite, as sodium homo-ionized and impregnated with iron nanoparticles. Iron nanoparticles were synthesized in the presence of the zeolite by chemical reduction. The evaluation of the removal ability was performed in a monocomponent (cadmium or methyl-orange dye) system by varying the contact time and its initial concentration. Removal capacity in a bi-component (cadmium and methyl orange) system was also studied while varying their concentrations. The characterization of the zeolites, before and after the sorption process, was carried out using several analytical techniques. The characteristics of zeolite clinoptilolite and iron particles were observed by scanning electron microscopy. The iron particles showed diameter sizes between 60 and 200 nm, localized on the surface of the zeolite. By IR spectroscopy no structural changes were detected for any of the treatments made to the zeolitic materials. By X-ray diffraction the clinoptilolite crystalline phase was mainly identified, however, it failed to detect any phase of iron in the zeolite impregnated with iron nanoparticles. Moessbauer spectroscopy indeed detected the impregnated iron phase as iron borides. The homo-ionized and iron nanoparticles impregnated zeolite showed no change in the specific surface area, or the isoelectric point, their values were 22.3 m{sup 2}/g and ph 9.8, respectively. However, whereas the active site density for the homo-ionized zeolite was 2.87 sites/nm{sup 2}, for iron nanoparticles impregnated zeolite was 20.32 sites/nm{sup 2}. As a result of the analysis of the isotherms of cadmium, the maximum sorption capacity of the homo-ionized zeolite was 35.03 mg/g and for the iron nanoparticles impregnated zeolite was 36.43 mg/g. These maximum sorption capacities represent up to 85% of removed cadmium from concentrations of 50 to 600 mg/L. For the removal of methyl

  20. Kinetic Modelling of the Removal of Multiple Heavy Metallic Ions from Mine Waste by Natural Zeolite Sorption

    Directory of Open Access Journals (Sweden)

    Amanda L. Ciosek

    2017-07-01

    Full Text Available This study investigates the sorption of heavy metallic ions (HMIs, specifically lead (Pb2+, copper (Cu2+, iron (Fe3+, nickel (Ni2+ and zinc (Zn2+, by natural zeolite (clinoptilolite. These HMIs are combined in single-, dual-, triple-, and multi-component systems. The batch mode experiments consist of a total initial concentration of 10 meq/L normality for all systems, acidified to a pH of 2 by concentrated nitric (HNO3 acid. A zeolite dosage of 4 g per 100 mL of synthetic nitrate salt aqueous solution is applied, for a contact period of 5 to 180 min. Existing kinetic models on HMIs sorption are limited for multi-component system combinations. Therefore, this study conducts kinetic analysis by both reaction and diffusion models, to quantify the sorption process. The study concludes that the process correlates best with the pseudo-second-order (PSO kinetic model. In the multi-component system combining all five HMIs, the initial sorption rate and theoretical equilibrium capacity are determined as 0.0033 meq/g·min and 0.1159 meq/g, respectively. This provides significant insight into the mechanisms associated with the sorption process, as well as contributing to the assessment of natural zeolite as a sorbent material in its application in industrial wastewater treatment.

  1. The thermal dehydration of natural zeolites

    NARCIS (Netherlands)

    Reeuwijk, van L.P.

    1974-01-01

    The zeolites constitute a group of minerals of much interest from geological, mineralogical and technological points of view. Structurally, they are tectosilicates with an 'open' framework containing channels and cavities which accommodate cations and water molecules. Generally, these

  2. Effect of the modification of a natural mexican zeolite in the sorption of cadmium and 4-chloro phenol; Efecto de la modificacion de una zeolita natural mexicana en la sorcion de cadmio y 4-clorofenol

    Energy Technology Data Exchange (ETDEWEB)

    Cortes M, R. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)

    2007-07-01

    Clinoptilolite type zeolite is a material of relative abundance in Mexico, which possess ion exchange properties and it can be used in the removal of metal ions from polluted waters. The external surface of zeolites can be modified with cationic surfactants. This modification could have a negative effect on the removal of metal ions and provides to the material the capacity to adsorb phenolic compounds. For this reason, it is important to know the capability of the modified material on the sorption of metal ions and phenolic compounds, simultaneously. The aim of this work was to evaluate the effect of the external surface modification with surfactant of a Mexican zeolite over its sorption capacity of cadmium and 4-chloro phenol, in batch and column systems. To accomplish that, a clinoptilolite type zeolitic rock from a deposit located in the state of Sonora, Mexico, was used. It was ground, sieved and characterized with different techniques; and its external surface area was modified with hexadecyltrimethylammonium bromide (HDTMA-Br). A grain size fraction was selected to carry out sorption kinetics and equilibrium experiments, as well as packed column tests with zeolitic material and solutions of cadmium and 4-chloro phenol. There are different models proposed in literature that are used to describe sorption kinetics and equilibrium. In this work, the sorption experimental results were adjusted to some of these models to identify controlling mechanisms on the kinetics and equilibrium of the studied systems. The results showed that the cadmium adsorption on natural and modified zeolite was similar in batch systems. For the case of 4-chloro phenol sorption, it was observed that natural zeolite does not retain this compound, while in modified zeolite the sorption is better than other comparable materials. The results also showed that for the case of cadmium sorption, the mechanism involved was ion exchange; while for sorption of 4-chloro phenol, a partition mechanism

  3. Modeling ion exchange in clinoptilolite using the EQ3/6 geochemical modeling code

    International Nuclear Information System (INIS)

    Viani, B.E.; Bruton, C.J.

    1992-06-01

    Assessing the suitability of Yucca Mtn., NV as a potential repository for high-level nuclear waste requires the means to simulate ion-exchange behavior of zeolites. Vanselow and Gapon convention cation-exchange models have been added to geochemical modeling codes EQ3NR/EQ6, allowing exchange to be modeled for up to three exchangers or a single exchanger with three independent sites. Solid-solution models that are numerically equivalent to the ion-exchange models were derived and also implemented in the code. The Gapon model is inconsistent with experimental adsorption isotherms of trace components in clinoptilolite. A one-site Vanselow model can describe adsorption of Cs or Sr on clinoptilolite, but a two-site Vanselow exchange model is necessary to describe K contents of natural clinoptilolites

  4. On the state of iron in a clinoptilolite

    International Nuclear Information System (INIS)

    Marco, J.F.; Gracia, M.; Gancedo, J.R.; Gonzalez-Carreno, T.; Arcoya, A.; Seoane, X.L.

    1995-01-01

    The characterization of an iron-containing natural zeolitic sample from the deposit of Tasajeras (Cuba) has been carried out by means of X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), 57 Fe Moessbauer spectroscopy and Fe K-edge X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS). The results show that iron is mainly located (ca. 96%) as Fe 3+ in an octahedral site of the clinoptilolite framework. No evidence of tetrahedrally coordinated Fe 3+ was found. The remaining 4% Fe is located as Fe 2+ in an extraframework octahedral site, probably as a solvated ion, within the clinoptilolite structure. (orig.)

  5. TITANIUM OXIDE DISPERSED ON NATURAL ZEOLITE (TiO2/ZEOLITE AND ITS APPLICATION FOR CONGO RED PHOTODEGRADATION

    Directory of Open Access Journals (Sweden)

    Is Fatimah

    2010-06-01

    Full Text Available The utilization of TiO2 dispersed on natural zeolite (TiO2/Zeolite for degradation of Congo Red photocatlytically has been performed. The TiO2/Zeolite was prepared by mechanically mixing of 100 g of natural zeolite, which it has been heated at 400oC, with TiO2 powder, the final weight ratio of the mixture was 5% (w/w. The mixture was then calcined at 400oC for 6 hours. The calcined product was characterized using x-ray diffractometry, x-ray fluorescence analysis and gas sorption analysis methods to determine its physicochemical properties changes caused by mixing and calcination. Investigation of Congo Red photodegradation using TiO2/Zeolite was carried out by mixing 25 mL 10-4 M solution of Congo Red with 25 mg of TiO2/Zeolite and irradiating the suspention with UV-light of 350 nm for 10, 20, 30, 40, 50 and 60 minutes, respectively. The characterization results showed that dispertion of TiO2 on zeolite resulted in the increasing of titanium concentration on TiO2/Zeolite. The concentration of Ti on natural zeolite was found to be 0.15%(w/w, meanwhile on TiO2/Zeolite was 2.29% (w/w. From X-ray diffractometry analysis result no information was found that TiO2 was dipersed on natural zeolite. It was caused by overlapping of the reflections of zeolite with reflections of TiO2. On the otherhand, the gas sorption analysis result exhibited that the dispersion of TiO2 on zeolite resulted in the decreasing of total pore volume as well as specific surface area of the natural zeolite. The specific surface areas of natural zeolite and TiO2/Zeolite were 21.98 and 16.74 m2/g, respectively, meanwhile the total pore volumes of natural zeolite and TiO2/Zeolite were 20.10x10-3 and 13.47x10-3 mL/g. The simple kinetic of photodegradation of Congo Red exhibited that the rate of degradation followed a first order kinetic and the reaction rate constant was 0.0017 minute-1.   Keywords: natural zeolite, TiO2, photodegradation, Congo Red

  6. Characterization of Mexican zeolite minerals; Caracterizacion de minerales zeoliticos mexicanos

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez C, M.J

    2005-07-01

    50% of the Mexican territory is formed by volcanic sequences of the Pliocene type, which appear extensively in the northwest states (Sonora, Sinaloa, Chihuahua, Durango) and west of Mexico (Jalisco and Nayarit), in central Mexico (Zacatecas, Guanajuato, San Luis Potosi, Queretaro, Hidalgo) and south of Mexico (Guerrero, Oaxaca); therefore, it is to be expected that in our country big locations of natural zeolites exist in its majority of the clinoptilolite type. The present study was focused toward the characterization of two Mexican natural zeolite rocks presumably of the clinoptilolite and filipsite types, one of them comes from the state of Chihuahua and the other of a trader company of non metallic minerals, due that these materials are not characterized, its are not known their properties completely and therefore, the uses that can be given to these materials. In this investigation work it was carried out the characterization of two Mexican zeolite rocks, one coming from the Arroyo zone, municipality of La Haciendita, in the state of Chihuahua; and the other one was bought to a trader company of non metallic minerals. The two zeolites so much in their natural form as conditioned with sodium; they were characterized by means of X-ray diffraction, scanning electron microscopy of high vacuum and elementary microanalysis (EDS), surface area analysis (BET), thermal gravimetric analysis. To differentiate the heulandite crystalline phase of the other clinoptilolite rock, its were carried out thermal treatments. The quantification of Al, Na, Ca, K, Mg, Fe was carried out in solution, by means of atomic absorption spectroscopy and the quantity of Si was determined by gravimetry. The zeolite rocks presented for the major part the crystalline heulandite and clinoptilolite phases for the most part, and it was found that the zeolite coming from the state of Chihuahua possesses a bigger content of heulandite and the denominated filipsite it is really a zeolite

  7. Applications of natural zeolites on agriculture and food production.

    Science.gov (United States)

    Eroglu, Nazife; Emekci, Mevlut; Athanassiou, Christos G

    2017-08-01

    Zeolites are crystalline hydrated aluminosilicates with remarkable physical and chemical properties, which include losing and receiving water in a reverse way, adsorbing molecules that act as molecular sieves, and replacing their constituent cations without structural change. The commercial production of natural zeolites has accelerated during the last 50 years. The Structure Commission of the International Zeolite Association recorded more than 200 zeolites, which currently include more than 40 naturally occurring zeolites. Recent findings have supported their role in stored-pest management as inert dust applications, pesticide and fertilizer carriers, soil amendments, animal feed additives, mycotoxin binders and food packaging materials. There are many advantages of inert dust application, including low cost, non-neurotoxic action, low mammalian toxicity and safety for human consumption. The latest consumer trends and government protocols have shifted toward organic origin materials to replace synthetic chemical products. In the present review, we summarize most of the main uses of zeolites in food and agruculture, along with the with specific paradigms that illustrate their important role. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  8. Adsorption of Zinc Contained in the Poultry Feedstuff onto Clinoptilolite

    Directory of Open Access Journals (Sweden)

    E. Šucman

    2007-01-01

    Full Text Available The aim of this work was to find whether an adsorbent used as an additive in the feed mixtures could influence the concentration of free available zinc. The feed supplement ZeoFeed, which often constitutes a part of animal feed mixtures, mainly for poultry, was used as adsorbent in the amount of 10 g kg-1 of the feed mixture. A substantial part of ZeoFeed is clinoptilolite, a natural form of zeolite. Two sample preparation methods were used for the determination of zinc. The microwave-assisted wet digestion method was used to achieve a complete decomposition of the feed mixture in order to determine the total zinc concentration. The extraction method represented a simplified model of the processes in the digestive fluid tract. The extraction was done under laboratory temperature for 30, 60 and 120 min. Concentrations of zinc both in digests and extracts were determined by the method of the differential pulse anodic stripping voltammetry. The total zinc concentration (mean ± 95% confidence interval in the feed mixture without addition of clinoptilolite was found to be 145 ± 32.0 mg kg-1 and in the feed mixture with added clinoptilolite 146 ± 11.5 mg kg-1. The concentrations of free available zinc were approximately ten times lesser than the total amount. The analysis of extracts showed that no statistically significant differences between concentrations of zinc in extracts without clinoptilolite and with clinoptilolite addition have been found. The extraction time did not affect the extracted amount of zinc significantly. In addition to zinc, also other three trace elements, namely the essential trace element copper and the toxic trace elements cadmium and lead, were measured. However, these data have only preliminary value and need further verification.

  9. Removal of ammonia from waste air streams with clinoptilolite tuff in its natural and treated forms

    Czech Academy of Sciences Publication Activity Database

    Ciahotný, K.; Melenová, L.; Jirglová, H.; Prokopová, Olga; Kočiřík, Milan; Eić, M.

    2006-01-01

    Roč. 12, č. 3 (2006), s. 219-226 ISSN 0929-5607 R&D Projects: GA ČR GA104/00/1007; GA ČR GP104/03/D183 Institutional research plan: CEZ:AV0Z40400503 Keywords : clinoptilolite tuffs * ammonia * adsorption * impregnation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.590, year: 2006

  10. Obtaining of iron particles of nanometer size in a natural zeolite; Obtencion de particulas de hierro de tamano nanometrico en una zeolita natural

    Energy Technology Data Exchange (ETDEWEB)

    Xingu C, E. G.

    2013-07-01

    The zeolites are aluminosilicates with cavities that can act as molecular sieve. Their crystalline structure is formed by tetrahedrons that get together giving place to a three-dimensional net, in which each oxygen is shared by two silicon atoms, being this way part of the tecto silicate minerals, its external and internal areas reach the hundred square meters for gram, they are located in a natural way in a large part of earth crust and also exist in a synthetic way. In Mexico there are different locations of zeolitic material whose important component is the clinoptilolite. In this work the results of three zeolitic materials coming from San Luis Potosi are shown, the samples were milled and sieved for its initial characterization, to know its chemical composition, crystalline phases, morphology, topology and thermal behavior before and after its homo-ionization with sodium chloride, its use as support of iron particles of nanometer size. The description of the synthesis of iron particles of nanometer size is also presented, as well as the comparison with the particles of nanometer size synthesized without support after its characterization. The characterization techniques used during the experimental work were: Scanning electron microscopy, X-ray diffraction, Infrared spectroscopy, specific area by means of BET and thermogravimetry analysis. (Author)

  11. Upgrading fertilizer production wastewater effluent quality for ammonium discharges through ion exchange with clinoptilolite.

    Science.gov (United States)

    Beler-Baykal, B; Allar, A D

    2008-06-01

    It had previously been shown that ammonium selective natural zeolite clinoptilolite may be used successfully as an ion exchanger for ammonium removal and nitrogen control from domestic wastewater. The process had been reported to be acceptable either by itself alone or as an upgrade. In this work, the possibility of using clinoptilolite for ammonium removal from fertilizer production wastewater was investigated. The fertilizer plant under consideration was rather a non-typical one with a lower ammonium strength than what is normally expected, and a variable effluent concentration. Batch experiments were performed to assess the capacity of clinoptilolite towards ammonium removal from an industrial wastewater at two different pHs. Flow experiments for the characterization of system behavior under continuous feeding conditions at different contact times were conducted for breakthrough analysis. Both real and simulated fertilizer wastewater samples were investigated and the results have shown that the real one may successfully be represented by the simulated one. Experimental results have shown that surface capacities exceeding 14 mg ammonium g(-1) clinoptilolite could be attained, complete removal of ammonium may be achieved with empty bed contact times of 10 min or higher and ion exchange with clinoptilolite could be used successfully to comply with the effluent standards given for the fertilizer plant.

  12. Effect of natural zeolite on biochemical and hematological parameters in blood, body mass and growth of calves

    Directory of Open Access Journals (Sweden)

    Šamanc Horea

    2008-01-01

    Full Text Available The work presents the results of investigations of the effect of natural zeolite (clinoptilolite type on the degree of resumption of cloistral immunoglobulin, the value of hematological parameters and enzyme activity in blood serum (AST, ALT, and LDH, body mass, and daily growth of calves in the first three months of life. Investigations were carried out on three groups of 10 male and female calves each, with a 1:1 ratio of sexes, (control, K, and two experimental groups, I and II, of the black-and-white breed, Holstein type. All three groups of calves were fed with the usual rations (colostrum, collective cows' milk, fodder mix with 18% total proteins, and Lucerne hay.The experimental groups of calves, as opposed to the controls, received colostrums and collective cows' milk with the addition of a preparation based on natural zeolite in quantities of 5 and 10 g/l milk. The concentration of immunoglobulin G in blood serum of experimental groups of calves was significantly higher than the values of the control group (35.9±6.43 g/l in Group I; 32.5±7.39 g/l in Group II; 20.8±6.88 g/l in control group K. The results of the investigations of the values of hematological parameters (number of erythrocytes, hemoglobin concentration, and hematocrit value do not show any digressions from the physiological values and are approximately the same in the experimental and the control groups of calves, which indicates that the examined quality of the zeolite-based preparation did not affect the degree of the resumption of iron and other oligoelements significant for erythropoietin. The data on the enzyme activity in blood serum indicate that the examined preparation does not cause any significant functional or morphological changes in the tissue of parenchymatous organs or muscles. There were no significant disorders in the health of calves of the experimental groups, while 3 calves of the control group had gastrointestinal disorders (diarrhea. Calves of

  13. Sorption of Cs-137 and Co-60 in Natural Zeolites

    International Nuclear Information System (INIS)

    Chales Suarez, G.; Moreno Alvarez, D.; Coutin Correa, D.

    1996-01-01

    The sorption of Cs-137 and Co-60 in natural zeolites under different conditions was studied. The behaviour of samples of mineral and rock from different deposit of the country was obtained and the decontamination of radioactive waters containing both radionuclides was performed; as part of the research to determine its application in the treatment of radioactive wastes in the country

  14. Efficacy of natural zeolite and pigments on yolk color and ...

    African Journals Online (AJOL)

    An in vivo study was conducted to evaluate pigment adsorptive ability of a natural zeolite in laying hens. This experiment was performed with three hundred sixty Hy-line W-36 strain of laying hens at 43 weeks of age. After a two weeks adaptation period, they received six experimental diets with a 3 × 2 factorial arrangement ...

  15. Plant of treatment of porcine waters with the use of the biogestion anaerobic and filtration with zeolite type clinoptilolite

    International Nuclear Information System (INIS)

    Nikolaeva, S.; Rua, F.; Mederos, B.

    2002-01-01

    Due to the worry by the contamination of the environment, the processing of the residuals waters should be focused from the ecological point of view and of the improvement of the human health. Today we know technologies that treat and purify practically any type of residual water; for this are taken into account aspects like: subsequent disposition, take advantage of the natural local conditions, cost of the construction of the installations, costs and facilities of operation and maintenance. To present an option of the pork residual water processing, a joint project between the Universidad Nacional and the Colegio Agropecuario de Santa Clara was presented, with the financial support of the German Agency of Technical Cooperation (GTZ) [es

  16. Preparation of natural zeolitic supports for potential biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Farias, Tania; Ruiz-Salvador, A. Rabdel [Zeolites Engineering Laboratory, Institute of Materials Science and Technology (IMRE), University of Havana, Vedado, 10400 Havana (Cuba); Velazco, Lya [Electronic Department, Institute of Materials Science and Technology (IMRE), University of Havana, 10400 Havana (Cuba); Menorval, Louis Charles de [Institut Charles Gerhardt Montpellier, UMR 5253 CNRS-UM2, Equipe Agregats, Interfaces et Materiaux pour l' Energie, C.C. 1502, Place Eugene Bataillon, 34095 Montpellier cedex 5 (France); Rivera, Aramis, E-mail: aramis@fisica.uh.cu [Zeolites Engineering Laboratory, Institute of Materials Science and Technology (IMRE), University of Havana, Vedado, 10400 Havana (Cuba)

    2009-12-15

    Considering the biological properties reported for the purified natural clinoptilolite, NZ, we prepared K- and Li-enriched forms aimed at release matrices for biomedical applications. The raw material and the obtained solid samples were characterized by means of atomic absorption spectroscopy, X-ray diffraction, {sup 27}Al and {sup 29}Si MAS nuclear magnetic resonance, and nitrogen adsorption. The results demonstrated the structural stability of the materials after the different transformations applied. The chemical behavior of the samples in bi-distilled water and hydrochloric acid was studied by pH and conductivity measurements. A preliminary study related with the liberation of K and Li in aqueous medium was carried out by atomic absorption spectroscopy. The studies showed that the release of both ions from the solid samples is favored in HCl solutions, and that lithium is released faster than potassium in both dissolution media.

  17. Equilibrium ion exchange studies of Ni2+ on homoionic forms of clinoptilolite

    Directory of Open Access Journals (Sweden)

    Joshua Gorimbo

    2014-05-01

    Full Text Available A natural zeolite (clinoptilolite that is mined in KwaZulu-Natal, South Africa, was evaluated for the removal of Ni2+ from wastewater. In particular, the effect of zeolite modification on Ni2+ removal from synthetic wastewater was investigated. The natural clinoptilolite was pretreated with 2 M metal chlorides for 24 h to yield near homoionic Na+, K+ and Ca2+ forms. A comparison of the isotherms for the Na+-Ni2+, K+-Ni2+, Ca2+-Ni2+ and natural-Ni2+ systems gave insight into how the displaced ion affects the selectivity of the clinoptilolite for Ni2+. The Na+, K+ and natural forms show highly selective convex isotherms whereas the Ca2+ form has a concave graph suggesting that the selectivity series is Ca2+> Ni2+> (Na+, K+, natural. Thermodynamic properties revealed that the Ni2+ sorption capacity increases as the values of the equilibrium constant and Gibbs free energy increase with increasing temperature from 298.15 K to 348.15 K. The enthalpy change was positive for all forms of clinoptilolite; values of 26.00 kJ/mol, 18.72 kJ/mol and 42.05 kJ/mol were obtained for exchange of Ni2+ into Na+, K+ and Ca2+ forms, respectively. The positive changes in enthalpy provide an indication that the sorption reaction is endothermic for Ni(II. The Gibbs free energy values were all negative except for Ca2+-exchanged clinoptilolite at 298.15 K and 308.15 K, for which the values were positive 3.10 kJ/mol and 0.53 kJ/mol, respectively. The entropy values for Ni2+ sorption were also positive; values of 0.12 kJ/mol.K, 0.08 kJ/mol.K and 0.14 kJ/mol.K were obtained for the Na+, K+ and Ca2+ forms, respectively. As expected, the enthalpy obtained from the Van’t Hoff plot is dependent not only on the metal ion being adsorbed, but also on the ion being displaced. Pretreatment of the zeolite enhances the removal efficiency provided that monovalent ions are used for the pretreatment. Thus clinoptilolite is an effective low-cost absorbent for the removal of Ni2+ from

  18. Synthesis of highly effective adsorbents from natural raw materials (zeolites)

    International Nuclear Information System (INIS)

    Shopova, N.; Schwieger, W.; Makraduli, M.

    1996-01-01

    Natural raw materials bentonite, silica tuff and diatomaceous earth from Macedonia were used in synthesis of zeolites type A, ZSM-5 and multilayer silicate magadiite-adsorbents. The bentonite was subject to pretreatment with acids (HCl and H 2 SO 4 - 5, 10, 15 and W%) or NaOH, and used in synthesis of zeolite type A having molar ratio of: 2Na 2 O : Al 2 O 3 : 2SiO 2 : 100H 2 O. Silicate tuff was applied (without any pretreatment, in a two stage reaction) in a high temperature synthesis, using butylamine as an organic 'template' component in order to get high silica zeolite type ZSM-5 having molar ratio of: 59.37SiO 2 : Al 2 O 3 : 3.84Na 2 O : 1.90R 2 O : 2025.10H 2 O. Multilayer silicate magadiite MS-H was synthesized from natural raw material diatomaceous earth. The product with a molar ratio of: 8SiO 2 : Na 2 O : 75H 2 O showed the best characteristics. The proposed method of alkaline pretreatment is a new one and it is acceptable from the economy point of view due to low energy consumption. The conclusion shows that the final result of the synthesis was not perfect, i.e. it has 70% of zeolite ZSM-5 and the rest were some amorphous phases. This product is suitable for industrial application in catalytic processes due to the fact that commercial catalyst contain typically 20 to 50% of zeolite type ZSM-5. On the other hand, the magadiite being multilayer silicate with no aluminium inside, is well suited as a carrier due to its ability of intercalation. The experimental results indicate that natural raw materials from Macedonia could be used for synthesis of synthetical silicates with high qualities and acceptable overall costs, specially when alkaline pretreatment is used. 14 refs., 4 tabs., 11 figs

  19. Modified Asphalt Binder with Natural Zeolite for Warm Mix Asphalt

    Directory of Open Access Journals (Sweden)

    Dubravský Marián

    2015-11-01

    Full Text Available In recent years, warm mix asphalt (WMA is becoming more and more used in the asphalt industry. WMA provide a whole range of benefits, whether economic, environmental and ecological. Lower energy consumption and less pollution is the most advantages of this asphalt mixture. The paper deals with the addition of natural zeolite into the sub base asphalt layers, which is the essential constituent in the construction of the road. Measurement is focused on basic physic – mechanical properties declared according to the catalog data sheets. The aim of this article is to demonstrate the ability of addition the natural zeolite into the all asphalt layers of asphalt pavement. All asphalt mixtures were compared with reference asphalt mixture, which was prepared in reference temperature.

  20. Functionalised natural zeolite and its potential for treating drinking ...

    African Journals Online (AJOL)

    , or 'blue baby' disease. Consequently, management of nitrate in drinking water is universally of public health interest. In this study, clinoptilolite functionalised with cationic surfactant hexadecyltrimethyl ammonium (HDTMA) was used for the ...

  1. Determination of {sup 60}Co sorption in natural clinoptilolite; Determinacion de la sorcion de {sup 60}Co en clinoptilolita natural

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez B, E.; Granados C, F. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    It was studied the clinoptilolite behavior coming from a deposit in Taxco, Guerrero in hydration and stabilization conditions with sodium for determining its sorption properties. The ion exchange process was carried out through gamma spectrometry using a CoCl{sub 2} solution marked with {sup 60} Co at p H 6.5 in different contact times. It was observed a maximum sorption of 0.408 m eq Co{sup +2}/g mineral, from 0.314 m eq Co{sup +2}/g mineral correspond at ion exchange. (Author)

  2. Investigation of the thermal behavior of Philippine natural zeolites

    Science.gov (United States)

    Olegario-Sanchez, Eleanor; Felizco, Jenichi Clairvaux; Mulimbayan, Francis

    2017-12-01

    This study aims to investigate the thermal behavior of natural zeolites from Mangatarem, Pangasinan, Philippines. Results obtained from the XRD pattern revealed that the sample is largely composed of mordenite, a Type I zeolite. In the chemical analysis, Si and Al are proven to be the primary components of the sample, which is typical in an aluminosilicate material. It also has a high Si/Al ratio, which suggests that the material is hydrophilic and thermally stable. The TGA analysis showed that dehydration processes dominate the sample's reaction upon heating up to 1000 °C. The initial dehydration process led to a weight loss that is almost equivalent to the moisture content, as measured by chemical analysis. The succeeding weight loss is most probably due to the dehydration of tightly-bound water and cation dehydration. No structural collapse was observed even up to 1000 °C, which suggests that the material is ideal for industrial applications. Lastly, FTIR results revealed that heating the zeolitic tuff led to possible de-alumination.

  3. PHENOL OXIDATION USING NATURAL ZEOLITE SUPPORTED METAL ION CATALYST

    Directory of Open Access Journals (Sweden)

    Sri Wardhani

    2010-06-01

    Full Text Available Phenol which contained in waste water has to be reduced and it could be done by oxygen oxidation.  In order to increase the rate of reaction it was needed a catalyst. In this research the capability of various catalysts, namely zeolite-Zn(II, zeolite-Cu(II and zeolite-Co(IIin oxidation of phenol has been investigated. The aim of this research was to study the type of metal ion catalyst towards the percentage of oxidated phenol. The oxidation process were carried out in an aqueous phenol of 100 ppm with oxygen flow rate of 200 mL/min. in the presence of catalysts with 0.2M of initial impregnation concentration. The capabilities of catalysts were performed by calculating the activation energy and it was done at two different temperatures, i.e. 70 and 90 oC. The percentage of oxidated phenol was determinated by measuring its concentration using UV-VIS spectrophotometer. In addition, the impregnated metal was calculated by measuring the ion concentration remains in the filtrate solution and it was determined using Atomic Absorption Spectrophotometer. The results showed that metal ion types affected the catalytic activity. The order of phenol oxidationactivity decreased as Co(II > Cu(II > Zn(II. The surface characteristics of catalysts were supported by pore volume and pore diameter i.e 0.009 cm3/g and 16.59 Å for Zn(II whereas specific surface area was 10.32 m2/g for Zn(II, 0.004 cm3/g and 24.37 Å for Cu(II whereas specific surface area was 3.57 m2/g for Cu(II, 0.001 cm3/g and 19.63 Å for Co(II whereas specific surface area was 10.26m2/g for Co(II.   Keywords: phenol,natural zeolite, catalyst, oxidation

  4. The potential of Saudi Arabian natural zeolites in energy recovery technologies

    International Nuclear Information System (INIS)

    Nizami, A.S.; Ouda, O.K.M.; Rehan, M.; El-Maghraby, A.M.O.; Gardy, J.; Hassanpour, A.; Kumar, S.; Ismail, I.M.I.

    2016-01-01

    Energy consumption in KSA (kingdom of Saudi Arabia) is growing rapidly due to economic development with raised levels of population, urbanization and living standards. Fossil fuels are currently solely used to meet the energy requirements. The KSA government have planned to double its energy generating capacity (upto 120 GW (gigawatts)) by 2032. About half of the electricity capacity of this targeted energy will come from renewable resources such as nuclear, wind, solar, WTE (waste-to-energy) etc. Natural zeolites are found abundantly in KSA at Jabal Shamah occurrence near Jeddah city, whose characteristics have never been investigated in energy related applications. This research aims to study the physical and chemical characteristics of natural zeolite in KSA and to review its potential utilization in selected WTE technologies and solar energy. The standard zeolite group of alumina–silicate minerals were found with the presence of other elements such as Na, Mg and K etc. A highly crystalline structure and thermal stability of natural zeolites together with unique ion exchange, adsorption properties, high surface area and porosity make them suitable in energy applications such as WTE and solar energy as an additive or catalyst. A simple solid–gas absorption system for storing solar energy in natural zeolites will be a cheap alternative method for KSA. In AD (anaerobic digestion), the dual characteristics of natural zeolite like Mordenite will increase the CH 4 production of OFMSW (organic fraction of municipal solid waste). Further investigations are recommended to study the technical, economical, and environmental feasibility of natural zeolite utilization in WTE technologies in KSA. - Highlights: • A highly crystalline structure is found in natural zeolites. • Natural zeolites will store solar energy in solid–gas absorption system. • The composites of natural zeolites will produce more liquid fuel like gasoline. • The natural zeolite will increase

  5. Zeolite

    Indian Academy of Sciences (India)

    49

    The unit cell volume change and the shift in XRD reflection positions. 18 showed a positive correlation with .... Molar ratios of the components in the gel with other conditions maintained during. 79 the synthesis of the MFI zeolite .... The reaction mixtures were analyzed by Gas Chromatography. 116. In the present study, the ...

  6. The effect of exchangeable cations in clinoptilolite and montmorillonite on the adsorption of aflatoxin B1

    Directory of Open Access Journals (Sweden)

    DRAGAN STOJSIC

    2001-08-01

    Full Text Available The adsorption of aflatoxin B1 (AFB1 by cation-exchanged clinoptilolite zeolitic tuff and montmorillonite was investigated at 37°C and pH 3.8 from an aqueous electrolyte having a composition similar to that of gastric juices of animals. Both minerals were exchanged from the natural form to the sodium form and then to the Cu2+, Zn2+ and Co2+-rich forms. The cation exchange was different for the different cations, but in all cases the exchanges were larger on montmorillonite than on clinoptilolite. The degree of exchange on montmorillonite was 76 % for copper (from a total of CEC 0.95 meq/g, Cu2+ –0.73 meq/g and 85 % for zinc and cobalt. Under the same conditions (concentration, temperature, pH, contact time, the degree of exchange on zeolitic tuff was 12 % for Cu2+ (from a total CEC of 1.46 meq/g, Cu2+ –0.17 meq/g, 8 % for Zn2+ and 10 % for Co2+. Both groups of mineral adsorbents showed high AFB1 chemisorption indexes (ca. For the montmorillonite forms, ca ranged from 0.75 for the Cu-exchanged montmorillonite to 0.89 for the natural Ca-form, 0.90 for the Zn-exchanged form and 0.93 for the Co-exchanged montmorillonite. The adsorption of AFB1 on the different exchanged forms of clinoptilolite gave similar values of ca for the Cu and Ca forms (0.90 and values of 0.94 and 0.95 for the Zn- and Co-exchanged form. The impact of the mineral adsorbents on the reduction of essential nutrients present in animal feed (Cu, Zn, Mn and Co showed that the Ca-rich montmorillonite had a higher capability for the reduction of the microelements than the Ca-rich clinoptilolite.

  7. Characterization of natural and modified zeolites using ion beam analysis techniques

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, E. [Instituto de Fisica, Departamento de Fisica Experimental, Universidad Nacional Autonoma de Mexico, Apdo. Postal 20-364, 01000 (Mexico)], E-mail: andrade@fisica.unam.mx; Solis, C. [Instituto de Fisica, Departamento de Fisica Experimental, Universidad Nacional Autonoma de Mexico, Apdo. Postal 20-364, 01000 (Mexico); Aceves, J.M.; Miranda, R. [Facultad de Estudios Superiores Cuautitlan Itzcalli, Departamento de Quimica, Universidad Nacional Autonoma de Mexico, 1 de Mayo S/N, Cuatitlan Itzcalli, Edo. de Mexico, C.P. 74540 (Mexico); Cruz, J. [Instituto de Fisica, Departamento de Fisica Experimental, Universidad Nacional Autonoma de Mexico, Apdo. Postal 20-364, 01000 (Mexico); Rocha, M.F. [Escuela Superior de Ingenieria Mecanica y Electrica, Instituto Politecnico Nacional, U.P. ' Adolfo Lopez Mateos' , Zacatenco, Del. Gustavo A. Madero, Mexico D.F. 07738 (Mexico); Zavala, E.P. [Instituto de Fisica, Departamento de Fisica Experimental, Universidad Nacional Autonoma de Mexico, Apdo. Postal 20-364, 01000 (Mexico)

    2008-05-15

    Zeolites are very important materials in catalytic and industrial processes. Natural, modified and synthetic zeolites have a wide range of uses because of their good adsorption, ion exchange capacity and catalytic properties. Mexico is an import source of natural zeolites, however their utilization in the natural form is limited due to the presence of trace metallic impurities. For example, metals such as vanadium and chromium inhibit the elimination of sulfur in hydrocarbons. Therefore, it is important to know the precise composition of the zeolite material. In this work, we report the elemental characterization of zeolites using various IBA techniques. {sup 3}He{sup +} and {sup 2}H{sup +} beams were used to measure the major element concentrations (Si, Al, O, C) by RBS and NRA. PIXE and SEM-EDS were used to measure the total trace element content (V, Cr, Fe, Ni, Cu, Zn, Rb, Sr, Zr, Pb, etc). Additionally, XRD was used to study the zeolite crystal structure.

  8. Ultrasonic-assisted hydrothermal synthesis and catalytic behavior of a novel SAPO-34/Clinoptilolite nanocomposite catalyst for high propylene demand in MTO process

    Science.gov (United States)

    Moradiyan, Eshagh; Halladj, Rouein; Askari, Sima; Moghimpour Bijani, Parisa

    2017-08-01

    SAPO-34 as a catalyst has high selectivity and hydrothermal stability, but it is rapidly deactivated by the formation of coke in its micropores. Evaluating the natural Clinoptilolite capability as a binder in nanocomposite catalysts is of interest because of its low cost, and accelerating the reaction. The SAPO-34/Clinoptilolite (S/C) nanocomposite catalysts were synthesized via ultrasonic-assisted hydrothermal method using Clinoptilolite as a binder. Subsequent performance of the catalyst was investigated in the methanol to olefins (MTO) reaction. The structures of synthesized nanocomposite were characterized with several methods such as XRD, XRF, FESEM, TEM, NH3-TPD, FT-IR, and nitrogen adsorption techniques. The modified Clinoptilolite was attained using nitric acid treatment. Although the physicochemical analysis indicated that HNO3-treatment decreases the crystallinity of the Clinoptilolite, the specific surface area of natural zeolite enhances considerably from 20.07 to 187.8 m2/g. The nanocomposite catalysts showed high selectivity toward light olefins with 100% conversion and 90% selectivity to light olefins as desired products at 450 °C. Nanocomposite with the additional diffusion paths for mass transfer provided by binder-filled space ascend to higher catalytic lifetimes in compare with free SAPO-34 catalyst.

  9. Kinetics of sorption of metal ions from seawater on the clinoptilolite

    International Nuclear Information System (INIS)

    Khamizov, R.Kh.; Butenko, T.Yu.; Veber, M.L.; Zajtseva, E.V.; AN SSSR, Vladivostok

    1990-01-01

    Comparative study of kinetics of Sr 2+ , Na + , Rb + ion sorption from seawater on sorbents of two types of the same graining was conducted. One of them was natural clinoptilolite (CL), another one - artifitial bidispersed sorbent, prepared by immobilization of powdered CL in high-permeable inert gelepolyacrylamide. It is shown that the rate of sorption processes is limited mainly by diffusion in zeolite microgranules. The characteristic sizes of microgranules for investigated CL are equal to 15-20 μm and are comparable with sizes of microcrystals, determined independently

  10. Ammonium ion interaction with conditioned natural zeolite with silver and its effect on the disinfection of polluted water in front of a consortium of gram (+) and gram (-) microorganisms

    International Nuclear Information System (INIS)

    Gonzaga G, V. E.

    2013-01-01

    Clinoptilolite zeolite material is a relative abundance in Mexico, which has ion exchange properties, therefore, has the ability to retain metal ions giving it an application in the process of disinfecting of water contaminated with pathogenic microorganisms. In this research, we conducted a study of disinfection of water contaminated with a microbial consortium, from a zeolite rock clinoptilolite from a deposit located in the State of Guerrero. Initially, the zeolite prepared by the grinding and sieving, for conditioning with NaCl and subsequently with AgNO 3 , finally to be characterized using the techniques of scanning electron microscopy and X-ray diffraction. Tests using columns packed with zeolite material, the effect of zeolite bactericidal conditioned with silver (ZGAg) against a microbial consortium consisting of Escherichia coli and Sthapyloccocus aureus in aqueous solution in the presence of ammonium ions used to increase the ion exchange with zeolite fitted with silver. To describe curves disinfecting a continuous flow system is adapted Gu pta model, which describes the kinetics and equilibrium adsorption process, considering the microorganisms as the adsorbate and the sanitizing agent (conditioned with silver zeolite) as the adsorbent. Characterization results show that in the scanning electron microscopy (Sem), no changes were obtained on the morphology of typical clinoptilolite crystals before and after that was modified with sodium and then with silver, it is worth mentioning however that fitted with silver zeolite (ZGAg), small particles are seen on the zeolite material which when analyzed by energy dispersive spectroscopy (EDS), we found a high concentration of Ag +. The disinfection period is increased as the concentration increased ammonium ions, this behavior is attributed to the ion exchange that occurs between the ammonium ions and silver ions. A lower percentage of inactivation is due, therefore, to a lesser amount of money available to be

  11. Functionalised natural zeolite and its potential for treating drinking ...

    African Journals Online (AJOL)

    Consequently, management of nitrate in drinking water is universally of public health interest. In this study, clinoptilolite functionalised with cationic surfactant hexadecyltrimethyl ammonium (HDTMA) was used for the removal of nitrate from drinking water. The effects of surfactant loading, adsorbent dosage, pH, coexisting ...

  12. Studies of adsorption and desorption of zinc ions on zeolites by means of 65Zn

    International Nuclear Information System (INIS)

    Foeldesova, M.; Dillinger, P.; Lukac, P.

    2001-01-01

    The uptake of different metals by natural and chemically modified ion-exchangers, including zeolites, were studied in order to minimize the contamination of environment with metals in ionic form. In recent years considerable attention has been devoted to the studies of chemically modified zeolites their properties and applications. The used zeolite originated from the deposit Nizny Hrabovec, eastern Slovakia (NH) and from deposit of Ukraine (U). The zeolite from Slovakia is a clinoptilolite /40 -70%/ type, the zeolite from Ukraine is a mixed mordenite /75%/ and clinoptilolite /25%/ type. A fraction of 1.5 -2.5 mm was separated from the grained zeolite by sieving. The sedimentary zeolites, being the siliceous zeolites, should exhibit substantial non-selectivity for the divalent cations having a high hydration enthalpy , including zinc ( -2026 kJ/g). Zinc is an essential trace element in all-living systems from bacteria to humans. The toxicity of zinc and most of zinc compounds is generally low, however, sometimes industrial and household wastes contain zinc in concentrations, which can be harmful to the environment. The zinc-accompanying impurities, such as cadmium and lead, are of much greater danger .The main source of zinc are waste waters and continuous emission from the production and processing of zinc, other nonferrous smelters, from coal power plants and fossil combustion. The static radio-exchange method using model radioactive solutions was utilized for the determination of the sorption of Zn by the mentioned above zeolitic materials. For this purpose the aqueous solution of 5 · 10 -2 mol dm -3 ZnCl 2 labelled with 65 Zn was used. The areas of application of natural zeolites have been well defined. However, their use can become more efficient after chemical modification. The zeolites acquire new valuable properties, while retaining their original ones. The obtained results make these materials excellent candidates for their potential use for waste water

  13. Measurement of cation exchange capacity (CEC) on natural zeolite by percolation method

    Science.gov (United States)

    Wiyantoko, Bayu; Rahmah, Nafisa

    2017-12-01

    The cation exchange capacity (CEC)measurement has been carried out in natural zeolite by percolation method. The natural zeolite samples used for cation exchange capacity measurement were activated beforehand with physical activation and chemical activation. The physically activated zeolite was done by calcination process at 600 °C for 4 hours. The natural zeolite was activated chemically by using sodium hydroxide by refluxing process at 60-80 °C for 3 hours. In summary, cation exchange capacity (CEC) determination was performed by percolation, distillation and titration processes. Based on the measurement that has been done, the exchange rate results from physical activated and chemical activated of natural zeolite were 181.90cmol (+)/kg and 901.49cmol (+)/kg respectively.

  14. CHARACTERIZATION OF NATURAL ZEOLITE AND DETERMINATION ITS ADSORPTION PROPERTIES

    Directory of Open Access Journals (Sweden)

    Marian HOLUB

    Full Text Available Pollution of water by toxic substances is one of the major reason concerning human health as well as the environmental quality. In terms of pollution, mining activities represent a serious threat. Countries of the middle Europe, where extraction of mineral resources takes place a long period, have to solve the problems of wastewater containing whole spectra of heavy metals, which are dangerous to the environment. Finding of the new and cheap ways of wastewater contaminated by heavy metals treatment can increase the quality of the environment in the affected localities and thus prevent adverse effects on fauna, flora or human beings. Sorption techniques belong to a cost effective methods that are able to effectively remove heavy metals. For the overall understanding of the sorption process, it is necessary to characterize and determine the properties of the used adsorbents. The paper deals with characterization of natural zeolite before and after sorption process under acidic conditions. The zeolite was characterized using Fourier transform infrared spectroscopy, X – ray diffraction, scanning electron microscopy and N2 adsorption/desorption isotherms.

  15. Application of chitin and zeolite adsorbents for treatment of low level radioactive liquid wastes

    International Nuclear Information System (INIS)

    Moattar, F.; Hayeripour, S.

    2004-01-01

    Two types of shrimp chitin derivatives and two types of Iranian natural zeolite derivates were studied for adsorption and treatment of low-level radioactive liquid waste. Chitin with lowers than 10% and chitosan with higher than 90% deacetylation factor were selected as neutral organic adsorbents. Natural clinoptilolite of Firuzkooh area and Na from derivates of it were selected as natural inorganic adsorbents. The static and dynamic ion exchange experimental results show that the ad adsorption efficiency depend on particle size, Ph, adsorbent type, deacetylation factor ( in chitin adsorbents) and cation type. The best Cs adsorption occurred in Na from clinoptilolite. Nevertheless chitin derivatives, particularly chitosan, are more efficient than zeolite adsorbents for removing of radionuclides such as 137 Cs, 54 Mn, 90 Sr and 60 Co. Adsorption performance was discussed and compared with each other

  16. Isotherms and kinetics of lead and cadmium uptake from the waste leachate by natural and modified clinoptilolite

    Directory of Open Access Journals (Sweden)

    Maryam Faraji

    2012-01-01

    Conclusions: The modified zeolite with surfactant can be used as an appropriate adsorbent for the separation of heavy metals from waste Leachate. Lead and cadmium were absorbed in a single layer on the surface of the modified zeolite with surfactant, comparing different isoterm models, indicated that the capacity of the modified zeolite for lead adsorption was more than cadmium adsorption, but cadmium was absorbed with higher energy.

  17. Multi-elemental characterization of Cuban natural zeolites

    International Nuclear Information System (INIS)

    Diaz Rizo, O.; Herrera Peraza, E.F.

    1996-01-01

    Concentrations of 38 elements in samples from four important Cuban zeolite bed have beam obtained by Instrumental Neutron Activation (INAA) and X-Ray Fluorescence Analysis (XRFA). In comparison with other analytical techniques good agreement was achieved. The concentration values of minor element Ba, Sr, Zn, and Mn, and 25 trace element (including 9 REE) are at the first time reported in Cuban zeolite. It is important for the zeolite evaluation in different industrial uses

  18. In-field evaluation of clinoptilolite feeding efficacy on the reduction of milk aflatoxin M1 concentration in dairy cattle

    Directory of Open Access Journals (Sweden)

    Panagiotis D. Katsoulos

    2016-06-01

    Full Text Available Abstract Background Clinoptilolite is a natural zeolite with high adsorption capacity for polar mycotoxins such as aflatoxins. The efficacy of clinoptilolite in ameliorating the toxic effects of aflatoxicosis has been proven in monogastric animals, but there is no such evidence for ruminants. The aim of this study was to evaluate, under field conditions, whether the dietary administration of clinoptilolite in dairy cows could reduce the concentration of aflatoxin M1 (AFM1 in bulk-tank milk, in farms with higher than or close to 0.05 μg/kg of milk (European maximum allowed residual level. An objective of the present study was also to investigate the effect of particle size of clinoptilolite on aflatoxin binding. Methods Fifteen commercial Greek dairy herds with AFM1 concentrations in bulk tank milk ≥0.05 μg/kg were selected. Bulk tank milk AFM1 was determined prior to the onset and on day 7 of the experiment. Clinoptilolite was added in the total mixed rations of all farms at the rate of 200 g per animal per day, throughout this period. Two different particle sizes of clinoptilolite were used; less than 0.15 mm in 9 farms (LC group and less than 0.8 mm in 6 farms (HC group. Results Clinoptilolite administration significantly reduced AFM1 concentrations in milk in all farms tested at an average rate of 56.2 % (SD: 15.11. The mean milk AFM1 concentration recorded on Day 7 was significantly (P < 0.001 lower compared to that of Day 0 (0.036 ± 0.0061 vs. 0.078 ± 0.0074 μg/kg. In LC group farms the reduction of milk AFM1 concentration was significantly higher than HC group farms (0.046 ± 0.0074 vs. 0.036 ± 0.0061 μg/kg, P = 0.002. As indicated by the Pearson correlation, there was a significant and strong linear correlation among the milk AFM1 concentrations on Days 0 and 7 (R = 0.95, P < 0.001. Conclusions Dietary administration of clinoptilolite, especially of smallest particle size, at the rate of

  19. Efficacy of natural zeolite and pigments on yolk color and ...

    African Journals Online (AJOL)

    user

    2011-04-16

    Apr 16, 2011 ... The YI was significantly affected by zeolite and pigment levels. Hens fed zeolite tended (P = 0.062) to lay eggs with a lighter shell weight (%) during the entire period compared with the control group. This effect was signifi- cant in 49 to 50 weeks of age, in a quadratic manner. A linear decrease in YI between ...

  20. Electrophilic Aromatic Iodine Substitution of 1-[(p-TolyliminoMethyl]-Naphthalen-2-Ol In Zeolite Catalyst

    Directory of Open Access Journals (Sweden)

    Murat Gündüz

    2011-12-01

    Full Text Available In this study, the naphtholic Schiff base has been reacted with iodine in the catalyst of natural zeolite clinoptilolite in order to synthesize iodine substituted Schiff base. The isolated product structure has been determined by IR, UV, 1H-NMR, 13C-NMR, Mass spectroscopy and elemental analysis. Under our reaction conditions it's found that the iodine is substituted to the phenyl ring of the naphtholic Schiff base.

  1. Peculiarities of the dielectric response of the silver-modified-zeolite porous microstructure

    Science.gov (United States)

    Bunyatova, U.; Ozturk Koc, S.; Orbukh, V. I.; Eyvazova, G. M.; Agamaliev, Z. A.; Lebedeva, N. N.; Koçum, İ. C.; Salamov, B. G.; Ozer, M.

    2016-10-01

    The aim of this study was to characterize electrical conductivity and dielectrical properties of the silver-exchanged zeolite - natural clinoptilolite from Western part of Turkey and Azerbaijan in the range of frequencies from 200 Hz to 1 MHz and at room temperature. For a better understanding the effect of concentration and content of silver in the nanoporous zeolite volume on the conductivity, a study of the dielectric properties of an un-modified and silver-modified zeolite plates with different amounts of Ag ions and Ag nanoparticles is performed. Un-modified and three different types of the silver ion-exchanged modified clinoptilolite plates were prepared. It was found, that with increasing silver concentration, resistance of zeolite plate monotonically decreases at the same time a capacitance is increases. It is suggested an explanation of the observed frequency dependence of the capacitance and resistance of zeolite plates on the silver concentrations may be explain on the basis of an electrode-dielectric interface gap model. At the same time, the observed phenomenon can be explained by considering the fact that with increasing content of silver the conductivity increases. These results show that Ag nanoparticles play significant role for performance improvement in plasma electronic devices with zeolite cathode.

  2. Penetrating waterproofing coatings based on slag -containing cements, modified by natural zeolites

    OpenAIRE

    Пушкарева, Екатерина Константиновна; Суханевич, Марина Владимировна; Бондарь, Екатерина Владимировна

    2014-01-01

    The paper deals with obtaining penetrating waterproofing coatings for concrete surfaces based on the slag-cement systems, modified by natural zeolite additives. The composition was investigated and physico-mechanical properties of slag-containing cements with natural zeolite, which were subsequently modified by the salt-electrolyte complex to create penetrating coating, were optimized. Studying the properties of the developed coating has confirmed its competitiveness in the market of similar ...

  3. ANAEROBIC DIGESTION OF WASTEWATER WITH HIGH SULFATE CONCENTRATION USING MICRO-AERATION AND NATURAL ZEOLITES

    Directory of Open Access Journals (Sweden)

    S. Montalvo

    Full Text Available Abstract The behavior of anaerobic digestion in batch and UASB reactors using a microaerobic process and natural zeolites was studied. Laboratory assays were carried out across 4 sets of variables: different COD/SO42- ratios, different airflow levels, with and without natural zeolites and room and mesophilic controlled temperatures. The microaerobic process demonstrated hydrogen sulfide removal levels exceeding 90% in most cases, while maintaining the flammable condition of the generated biogas. The level of COD removal exceeded 75% in UASB reactors despite their operation under very low hydraulic retention times (2.8-4.8 hours. The effectiveness of natural zeolites in accelerating UASB reactor startup was demonstrated. Results showing the positive influence of zeolites on the granulation process in UASB reactors were also achieved.

  4. K/AR dating of clinoptilolite, mordenite, and associated clays from Yucca Mountains, Nevada

    International Nuclear Information System (INIS)

    WoldeGabriel, G.

    1993-01-01

    Zeolites are abundant in the geologic record in both continental and marine environments. The purpose of the present study is to evaluate the utility of K-bearing zeolites for dating by the K/Ar method to determine the time of zeolite diagenesis at Yucca Mountain, Nevada (Fig. 1). At Yucca Mountain, K-rich clinoptilolite and possibly mordenite are the only potentially K/Ar dateable secondary minerals present in the zeolite-rich tuffs except for some illite/smectites (≥10% illite layers) associated with these minerals. Direct dating of K-rich clinoptilolite, the most abundant zeolite in the altered tuffs, is important to delineate zeolite chronology as part of the site characterization of Yucca Mountain

  5. Properties of diclofenac sodium sorption onto natural zeolite modified with cetylpyridinium chloride.

    Science.gov (United States)

    Krajišnik, Danina; Daković, Aleksandra; Milojević, Maja; Malenović, Anđelija; Kragović, Milan; Bogdanović, Danica Bajuk; Dondur, Vera; Milić, Jela

    2011-03-01

    In this study an investigation of a model drug sorption onto cationic surfactant-modified natural zeolites as a drug formulation excipient was performed. Natural zeolite was modified with cetylpyridinium chloride in amounts equivalent to 100, 200 and 300% of its external cation-exchange capacity. The starting material and obtained organozeolites were characterized by Fourier transform infrared spectroscopy, zeta potential measurements and thermal analysis. In vitro sorption of diclofenac sodium as a model drug was studied for all surfactant/zeolite composites by means of sorption isotherm measurements in aqueous solutions (pH 7.4). The modified zeolites with three levels of surfactant coverage within the short activation time were prepared. Zeta potential measurements and thermal analysis showed that when the surfactant loading level was equal to external cation-exchange value, almost monolayer of organic phase were present at the zeolitic surface while higher amounts of surfactant produced less extended bilayers, ordered bilayers or admicelles at the zeolitic surface. Modified zeolites, obtained in this manner, were effective in diclofenac sodium sorption and the organic phase derived from adsorbed cetylpyridinium chloride was the primary sorption phase for the model drug. The Langmuir isotherm was found to describe the equilibrium sorption data well over the entire concentration range. The separate contributions of the adsorption and partition to the total sorption of DS were analyzed mathematically. Results revealed that that adsorption and partitioning of the model drug take place simultaneously. 2010 Elsevier B.V. All rights reserved.

  6. Peculiarities of unusual electret state in porous zeolite microstructure

    Science.gov (United States)

    Bunyatova, U.; Orbukh, V. I.; Eyvazova, G. M.; Lebedeva, N. N.; Agamaliev, Z. A.; Koçum, I. C.; Ozer, M.; Salamov, B. G.

    2017-11-01

    This study explores, for the first time to our knowledge, the influence of electret state on the dielectric parameters of porous zeolite of frequencies up to 106 Hz, at room temperature and normal atmospheric pressure. The I-V characteristics with unusual hysteresis loop in the wide pressure range were measured on zeolite plates having three different material characteristics: A) plate, cut out from a monoblock natural zeolite; B) plate, modified by silver ions, and C) plate containing silver nanoparticles. Zeolite samples were exposed to an electric field (Ep = 2 kV cm-1) in an air atmosphere for 240 min. It is established, that the stability of electret state and value of the dielectric response ε‧ and ε″ for clinoptilolite Ag nanoparticles containing plates changed under influence of DC electric field. During some time the dielectric response is restored and observed unique phenomenon indicates on the electret behavior of clinoptilolite samples. These changes are observed within a few days consequently, there is long-term dynamics of the dielectric response changes. This interpretation is based on the assumption that due influence of the dc electric field part of the silver atoms in nanoparticles decays into ions and electrons.

  7. Phase transitions on dehydration of the natural zeolite thomsonite

    DEFF Research Database (Denmark)

    Ståhl, Kenny

    2001-01-01

    The dehydration of the natural zeolite thomsonite, Na4CasAl20Si20O80 24H(2)O, has been studied using a combination of conventional and synchrotron X-ray powder diffraction. A preliminary in situ dehydration study revealed two distinct unit cell changes at approximately 540 and 570 K, respectively...... coordinate two waters each. Thomsonite, heat treated at 523 K: Spacegroup Pncn, a = 13.0032(1), b = 12.9814(1), c = 13.2486(1) Angstrom, and 16 water/unit cell. Up to the first phase transition W3 and W4, both coordinated by the mixed CaA/Na site, are expelled. Thomsonite, heat treated at 553 K-Spacegroup Pn......2n, a = 13.0814(2), b = 13.0429(2), c = 13.2004(2) Angstrom, and 12 water/unit cell. During the phase transition at about 540 K the mixed CaA/Na site is separate into distinct CaA and Na sites. As the Na sites do not require water coordination another 1/6 of the original water contents may...

  8. Control of Natural Zeolite Properties by Mechanical Activation in Stirred Media Mill

    Directory of Open Access Journals (Sweden)

    Bohács K.

    2017-06-01

    Full Text Available Due to the special characteristics of zeolites, they can be applied in a very wide range of industries, i.e. agricultural, environmental or water treatment purposes. Generally, high added value zeolite products are manufactured by micro- or nanogrinding. However, these processes require high energy input and cause significant wearing of the mill parts. Therefore, the optimization of zeolite grinding, as well as the control of its properties are of a great importance. In the present paper a Hungarian natural zeolite was mechanically activated in stirred media mill for various residence times in distilled water, meanwhile the particle size distribution and the grinding energy were measured. Additionally, on-line tube rheometer was used to study the rheology of the suspension during the grinding process. The particle interaction and the suspension aggregation stability were detected by zeta-potential measurements. Structural changes due to the mechanical activation process were monitored by FTIR. It was found that the material structure of the zeolite, as well as the rheological behaviour of the zeolite suspension and its aggregation stability had been altered due to the mechanical activation in the stirred media mill. It can be concluded that the zeolite product properties can be modified by mechanical activation in order to produce a high added value tailored material.

  9. Effect of Nitrogen Level and Natural Zeolite on Qualitative and Quantitative Function of Stevia rebaudiana (Bertoni in Ahvaz Climatic Condition

    Directory of Open Access Journals (Sweden)

    A Bakgshandeh

    2016-10-01

    Full Text Available Introduction Nowadays due to population growth and higher levels of welfare, one of the main social problems is providing appropriate food resources. In this regard, finding the alternative food resources, improvement of existing technologies and providing new technologies seem inevitable. Although sugar is a very important substance and has special place in household’s basket and economy, the harmful effects of excessive consumption of sugar should not be neglected. Stevia is a plant with a widespread root system which has a couple of years lifetime. The stems of Stevia are brittle and small and produce elliptical leaves. At first the leaves will be dried and then they will be powdered or wetted in the water and will be used for sweetening of beverages, sweet drinks, chewing gums, chocolates, cakes, etc. Stevia is one of 950 genera belonging to the family of Asteraceae plant. Stevia leaves are used for sweetening foods. Sweetness of Stevia comes from the d. terpenoides glycosides that exist in different parts of the plant. Glycosides are the result of secondary metabolism in the plants. In different components of the Stevia body, there are about 10 major glycoside compositions which the steviozede and Rbadiozide glycosides have more importance in sweetening property of Stevia compared to other sweet glycosides. Nitrogen is considered as one of the key elements in the nutrition of crops and the most important element in limiting the plant growth. Due to increased cation exchange capacity and a high tendency to absorb and retain ammonium, use of clinoptilolite on agricultural lands can have an effective role in reduction of nutrient washing especially nitrogen from soil. Materials and Methods In order to investigate the effect of different levels of nitrogen and natural zeolite on qualitative and quantitative yield of Stevia in Ahvaz climate, a trial agricultural research field was selected at the farm of agricultural and natural resources of

  10. Equilibrium CO{sub 2} adsorption on zeolite 13X prepared from natural clays

    Energy Technology Data Exchange (ETDEWEB)

    Garshasbi, Vahid [Faculty of Chemical, Petroleum and Gas Eng., Semnan University, P.O. Box 35196-45399, Semnan, Islamic Republic of Iran (Iran, Islamic Republic of); Jahangiri, Mansour, E-mail: mjahangiri@semnan.ac.ir [Faculty of Chemical, Petroleum and Gas Eng., Semnan University, P.O. Box 35196-45399, Semnan, Islamic Republic of Iran (Iran, Islamic Republic of); Anbia, Mansoor [Research Laboratory of Nanoporous Materials, Faculty of Chemistry, Iran University of Science and Technology, Tehran 16846-13114, Islamic Republic of Iran (Iran, Islamic Republic of)

    2017-01-30

    Highlights: • Zeolite 13X was successfully synthesized by hydrothermal treatment using natural kaolin, natural bentonite and natural feldspath. • The optimum conditions of synthesis zeolite 13X were found to be NaOH concentration = 4 M and crystallized at 65 °C for 72 h after homogenization by agitated at room temperature for 120 h. • The prepared zeolite 13X from natural kaolin (13X-K) showed a high BET surface area of 591 m{sup 2}/g and high micropore volume (0.250 cm{sup 3}/g) than other materials in this study. • The adsorption behavior of carbon dioxide and methane on zeolite 13X sample at different temperature from 298 K to 328 K was investigated. • It was found that the Langmuir–Freundlich model was more suitable than the others for description of CO{sub 2} adsorption isotherms. - Abstract: Zeolite 13X was successfully synthesized by hydrothermal treatment using natural clays extracted from Iranian resources. The preliminary natural materials and the final zeolite 13X samples were characterized by X-ray Diffraction (XRD), Fourier-Transfer Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM) and N{sub 2} adsorption–desorption isotherm. The effects of various factors such as NaOH addition amount and aging time on the crystalline products were studied during the synthesis process. The optimum conditions related to the synthesis of zeolite 13X were set. Accordingly, NaOH concentration was equal to 4 M. It was further crystallized at 65 °C for 72 h after its homogenization by agitation at room temperature for 120 h. In this study, the zeolite 13X prepared from natural kaolin (13X-K) showed a high BET surface area of 591 m{sup 2}/g with higher micropore volume (0.250 cm{sup 3}/g) than other materials. Adsorption equilibrium isotherms of CO{sub 2} were investigated using a static, volumetric method. In addition, pressures for the pure component data extended up to 20 bar. The adsorption equilibrium data of CO{sub 2} was fitted to

  11. The Effect of Zeolite on Aggregate Stability Indices

    Directory of Open Access Journals (Sweden)

    F. Sohrab

    2016-02-01

    Full Text Available Introduction: Soil structural stability affects the profitability and sustainability of agricultural systems. Particle size distribution (PSD and aggregate stability are the important characteristics of soil. Aggregate stability has a significant impact on the development of the root system, water and carbon cycle and soil resistance against soil erosion. Soil aggregate stability, defined as the ability of the aggregates to remain intact when subject to a given stress, is an important soil property that affects the movement and storage of water, aeration, erosion, biological activity and growth of crops. Dry soil aggregate stability (Mean Weight Diameter (MWD, Geometric Mean Diameter (GMD and Wet Aggregate Stability (WAS are important indices for evaluating soil aggregate stability.To improve soil physical properties, including modifying aggregate, using various additives (organic, inorganic and chemicals, zeolites are among what has been studied.According to traditional definition, zeolites are hydratealuminosilicates of alkaline and alkaline-earth minerals. Their structure is made up of a framework of[SiO4]−4 and [AlO4]−5 tetrahedron linked to each other's cornersby sharing oxygen atoms. The substitution of Si+4 by Al+3 intetrahedral sites results inmore negative charges and a high cation exchange capacity.Zeolites, as natural cation exchangers, are suitable substitutes to remove toxic cations. Among the natural zeolites,Clinoptilolite seems to be the most efficient ion exchanger and ion-selective material forremoving and stabilizing heavy metals.Due to theexisting insufficient technical information on the effects of using different levels of zeolite on physical properties of different types of soils in Iran, the aim of this research was to assess the effects of two different types of zeolite (Clinoptilolite natural zeolite, Z4, and Synthetic zeolite, A4 on aggregate stability indicesof soil. Materials and Methods: In this study at first

  12. The removal of heavy metals from aqueous solution using natural Jordanian zeolite

    Science.gov (United States)

    Taamneh, Yazan; Sharadqah, Suhail

    2017-07-01

    In this article, the adsorption process of cadmium and copper using natural Jordanian (NJ) zeolite as adsorbent has been experimentally estimated. The samples of NJ zeolite were obtained from Al Mafraq discrete, north east of Jordan. The influence of the bulk concentration ( C o), contact time ( t) and different adsorbent masses ( m) of NJ zeolite on the removal of heavy metal were evaluated. These variables had a considerable function in promoting the sorption process of heavy metal using the NJ zeolite. The initial concentration of heavy metals in the stock solution was extended between 80 and 600 mg/L. The batch adsorption method was employed to investigate the adsorption process. The experimental data were correlated using Freundlich and Langmuir empirical formula. The ability of NJ zeolite to eliminate cadmium and copper was estimated according to Langmuir isotherm empirical formula and found 25.9 and 14.3 mg/g for cadmium and copper, respectively. The kinetics of adsorption of cadmium and copper have been analyzed and correlated by first-order and second-order reaction model. It was noticed that adsorption of cadmium and copper was better correlated with pseudo-second-order kinetic model. The results presented that NJ zeolite is practical adsorbent for removing cadmium and copper ion metal.

  13. Efficacy of supplemental natural zeolite in broiler chickens subjected to dietary calcium deficiency

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    Erol Bintaş

    2014-04-01

    Full Text Available Natural zeolite, or sodium aluminosilicate, influences calcium (Ca and phosphorus (P utilisation in chicks. A 2×2 factorial arrangement of treatments was used to investigate the effect of dietary Ca (recommended and below recommended levels and zeolite (0 and 0.8% on growth, plasma, tibia and faeces in chickens from 1 to 42 days of age. Zeolite supplementation did not affect overall body weight (BW gain, feed intake (FI or feed conversion ratio (FCR of broiler chickens (P>0.05. Overall mortality of zeolite-fed chickens was lower than in untreated ones (P<0.01. Reduction of dietary Ca of approximately 10 to 18% decreased (P<0.05 BW at 14 and 42 days of age in association with reduced FI, but overall FCR was unchanged. Serum protein and sodium constituents were reduced in birds fed zeolite (P<0.05. Decreasing dietary Ca level increased (P<0.01 serum, total protein and glucose concentrations, but decreased Ca level. Zeolite decreased bone ash in birds fed a Ca-deficient diet while increased faecal excretion of ash, Ca, P and aluminum. However, zeolite increased tibia weight (P<0.05 and thickness (P<0.01. No significant response (P>0.05 in relative weight and gross lesion scores of liver or footpad lesion scores was found related to changes in dietary regimens. The results of the present study do not corroborate the hypothesis that the effectiveness of zeolite may be improved in Ca-deficient diets in association with its ion exchange capability.

  14. PREPARATION, CHARACTERIZATIONS AND MODIFICATION OF Ni-Pd/NATURAL ZEOLITE CATALYSTS

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    Wega Trisunaryanti

    2010-06-01

    Full Text Available Preparation, and modification of Ni-Pd/natural zeolite as well as their characterizations had been carried out. The aim of this research for the fututure is to prepare the best characters catalyst for the conversion of waste plastics fraction to gasoline fraction (C5-C12 hydrocarbons. The preparation of catalysts was performed by reacting a natural zeolite with the precursor of Ni(NO32. 9H2O and PdCl2 in an ammonia solution (25%. The modifications were performed by varying the rasio of Ni/Pd loaded to the zeolite, whereas the Pd was previously loaded and total metal content was 1 wt.% based on the zeolite. The characterization of catalysts included determination of acidity gravimetrically by adsorption of ammonia or pyridine vapour  base method, metal content by Atomic Adsorption Spectrophotometer (AAS and X-ray Fluoresence (XRF and crystallinity by X-ray Diffraction (XRD. The treatment of catalysts using Etilene Diamine Tetra Acetic acid  (EDTA was performed to study the metal distribution on the outer or inner surface of the zeolite. The characterization results showed that the loading of metals to the zeolite increased its acidity and decreased its spesific surface area, however, did not defect its crystallnity.  The metals loaded on the zeolite were distributed inside the pore and at outer surface of the zeolite. For all catalyst samples, the acidities determined using ammonia were higher than those of pyridine, and the acidities determined before the EDTA treatment was lower than those after the treatment.  Metal contents of the zeolite before the EDTA treatment were higher than those after the treatment. The EDTA treatment enhanced the crystallinity of the sampel. The relationship between the metal rasio towards the acidity of the catalyst samples were in variation. Catalyst samples produced in this research have good characters, thus promisingly can be used for conversion process of waste plastics to gasoline fraction.    Keywords

  15. Hydrophobic surface functionalization of Philippine natural zeolite for a targeted oil remediation application

    Science.gov (United States)

    Osonio, Airah P.; Olegario-Sanchez, Eleanor M.

    2017-12-01

    The objective of this study is to modify and compare the oil sorption capacity on the surface of natural zeolite (NZ) and functionalized natural zeolite (FNZ) and to compare with activated charcoal samples. The NZ samples were surface modified via esterification process and characterized using XRD, SEM, and IR spectroscopy. The NZ, FNZ and activated charcoal were then tested using ASTM method F726-12 to validate the oil sorption capacity and TGA was used for the oil selectivity of the adsorbents. The results indicate that FNZ has an improved oil/water adsorption capacity than NZ when functionalized with ester and has a comparable capacity with activated charcoal.

  16. Simultaneous removal of iron and manganese of aqueous solutions using as adsorbent a Mexican natural zeolite

    International Nuclear Information System (INIS)

    Garcia M, A.; Solache R, M. J.; Olguin G, M. T.

    2009-01-01

    In this work was evaluated the removal capacity of iron and manganese of aqueous solutions using a Mexican natural zeolite. It was observed that the Freundlich pattern describes the adsorption process appropriately and that a competitive effect exists between both metals by the exchange places of the zeolite, when it is starting of solutions that contain to both metals, impacting mainly in the manganese removal. A natural zeolite coming from the Puebla State, Mexico was used. The material was milled and sieved to a mesh size 30 and was conditioned with a solution 0.5 N of sodium chloride. Later on was characterized by means of scanning electron microscopy and X-ray diffraction.

  17. Kinetic Adsorption Study of Silver Nanoparticles on Natural Zeolite: Experimental and Theoretical Models

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    Alvaro Ruíz-Baltazar

    2015-12-01

    Full Text Available In this research, the adsorption capacity of Ag nanoparticles on natural zeolite from Oaxaca is presented. In order to describe the adsorption mechanism of silver nanoparticles on zeolite, experimental adsorption models for Ag ions and Ag nanoparticles were carried out. These experimental data obtained by the atomic absorption spectrophotometry technique were compared with theoretical models such as Lagergren first-order, pseudo-second-order, Elovich, and intraparticle diffusion. Correlation factors R2 of the order of 0.99 were observed. Analysis by transmission electron microscopy describes the distribution of the silver nanoparticles on the zeolite outer surface. Additionally, a chemical characterization of the material was carried out through a dilution process with lithium metaborate. An average value of 9.3 in the Si/Al ratio was observed. Factors such as the adsorption behavior of the silver ions and the Si/Al ratio of the zeolite are very important to support the theoretical models and establish the adsorption mechanism of Ag nanoparticles on natural zeolite.

  18. La roca magica: uses of natural zeolites in agriculture and industry.

    Science.gov (United States)

    Mumpton, F A

    1999-03-30

    For nearly 200 years since their discovery in 1756, geologists considered the zeolite minerals to occur as fairly large crystals in the vugs and cavities of basalts and other traprock formations. Here, they were prized by mineral collectors, but their small abundance and polymineralic nature defied commercial exploitation. As the synthetic zeolite (molecular sieve) business began to take hold in the late 1950s, huge beds of zeolite-rich sediments, formed by the alteration of volcanic ash (glass) in lake and marine waters, were discovered in the western United States and elsewhere in the world. These beds were found to contain as much as 95% of a single zeolite; they were generally flat-lying and easily mined by surface methods. The properties of these low-cost natural materials mimicked those of many of their synthetic counterparts, and considerable effort has made since that time to develop applications for them based on their unique adsorption, cation-exchange, dehydration-rehydration, and catalytic properties. Natural zeolites (i.e., those found in volcanogenic sedimentary rocks) have been and are being used as building stone, as lightweight aggregate and pozzolans in cements and concretes, as filler in paper, in the take-up of Cs and Sr from nuclear waste and fallout, as soil amendments in agronomy and horticulture, in the removal of ammonia from municipal, industrial, and agricultural waste and drinking waters, as energy exchangers in solar refrigerators, as dietary supplements in animal diets, as consumer deodorizers, in pet litters, in taking up ammonia from animal manures, and as ammonia filters in kidney-dialysis units. From their use in construction during Roman times, to their role as hydroponic (zeoponic) substrate for growing plants on space missions, to their recent success in the healing of cuts and wounds, natural zeolites are now considered to be full-fledged mineral commodities, the use of which promise to expand even more in the future.

  19. Adsorption of Free Fatty Acid (FFA) in Low-Grade Cooking Oil Used Activated Natural Zeolite as Adsorbent

    Science.gov (United States)

    Larasati Tres Ayu Putranti, Monika; Kompiang Wirawan, Sang; Made Bendiyasa, I.

    2018-01-01

    Adsorption of free fatty acid (FFA) in low-grade cooking oil using active natural zeolite adsorbent was done as an effort to improve the quality of low-grade cooking oil so that it can fulfill the standard of fried oil which has been set on SNI 01-3741-2013. Adsorption was carried out with natural zeolite which activated with HCl and NaOH solution followed by the calcination process. The results showed that the NaOH activated zeolite decreased FFA content in low-grade cooking oil more than the HCl activated natural zeolite, with optimum NaOH concentration was 0.75 M. In the adsorption equilibrium analysis with temperature variation (25 °C, 40 °C, 80 °C ), obtained that adsorption of FFA with NaOH activated natural zeolite follows Adsorption Isotherm Freundlich Model with equilibrium constant value was 20,5873; 0,9629 dan 0,8053.

  20. Natural Jordanian zeolite: removal of heavy metal ions from water samples using column and batch methods.

    Science.gov (United States)

    Baker, Hutaf M; Massadeh, Adnan M; Younes, Hammad A

    2009-10-01

    The adsorption behavior of natural Jordanian zeolites with respect to Cd(2 + ), Cu(2 + ), Pb(2 + ), and Zn(2 + ) was studied in order to consider its application to purity metal finishing drinking and waste water samples under different conditions such as zeolite particle size, ionic strength and initial metal ion concentration. In the present work, a new method was developed to remove the heavy metal by using a glass column as the one that used in column chromatography and to make a comparative between the batch experiment and column experiment by using natural Jordanian zeolite as adsorbent and some heavy metals as adsorbate. The column method was used using different metal ions concentrations ranged from 5 to 20 mg/L with average particle size of zeolite ranged between 90 and 350 mum, and ionic strength ranged from 0.01 to 0.05. Atomic absorption spectrometry was used for analysis of these heavy metal ions, the results obtained in this study indicated that zeolitic tuff is an efficient ion exchanger for removing heavy metals, in particular the fine particle sizes of zeolite at pH 6, whereas, no clear effect of low ionic strength values is noticed on the removal process. Equilibrium modeling of the removal showed that the adsorption of Cd(2 + ), Cu(2 + ), Pb(2 + ), and Zn(2 + ) were fitted to Langmuir, Freundlich and Dubinin-Kaganer-Radushkevich (DKR). The sorption energy E determined in the DKR equation (9.129, 10.000, 10.541, and 11.180 kJ/mol for Zn(2 + ), Cu(2 + ), Cd(2 + ) and Pb(2 + ) respectively) which revealed the nature of the ion-exchange mechanism.

  1. Mexican natural zeolite, material for their possible use in the hydrogen storage

    International Nuclear Information System (INIS)

    Iturbe G, J. L.; Vazquez A, O.

    2009-01-01

    In this work a study is presented on the use of a Mexican natural zeolite as possible alternative to storage hydrogen. This zeolite material comes from the Sonora State (Mexico), to which is diminished the particle size by means of a mill treatment with a mechanical alloyed system during 5 hours. Later on, the zeolite in powder form was characterized by means of X-ray diffraction and scanning electron microscopy. It was also exposed to heating in a micro-reactor at 350 C and at the same time making empty during 2 hours, to eliminate humidity and possible gases that were caught in their structure. Soon after, it was diminished the temperature at 10 C and it was contacted with hydrogen of ultra high purity to a pressure of 10 bars during 10 minutes. The hydrogen analysis caught in the zeolite was realized through gas chromatography. The results by means of the chromatograms indicate that the zeolite adsorbed and liberate to hydrogen under conditions completely different to that reported in the literature, being understood that under our experimental conditions to low pressure and temperature, the hydrogen is adsorbed in this material type. (Author)

  2. Malachite green adsorption onto natural zeolite and reuse by microwave irradiation

    International Nuclear Information System (INIS)

    Han Runping; Wang Yu; Sun Qing; Wang Lulu; Song Jiyun; He Xiaotian; Dou Chanchan

    2010-01-01

    Natural zeolite was used for the removal of malachite green (MG) from aqueous solution in batch mode and reused by microwave irradiation. The isotherm data were analyzed by the Langmuir, Freundlich, Redlich-Peterson, and Koble-Corrigan isotherm model. The better fit for the equilibrium process was Koble-Corrigan model. The kinetic studies indicated that the adsorption followed the pseudo-second-order kinetic. Thermodynamic calculations showed that the adsorption was spontaneous and endothermic process. Spent zeolite was treated by microwave irradiation and it was found that yield of regeneration was 85.8% in the case of microwave irradiated time 10 min at 160 W.

  3. Quality improvement of fishery water using natural zeolite and dynamics of adsorption of hydrological toxicants

    Directory of Open Access Journals (Sweden)

    Obradović Saša

    2006-01-01

    Full Text Available The adsorption capability of the natural mineral zeolite of domestic origin, on chemical parameters in water used for the intensive breeding of the Rainbow Trout was investigated in practical and laboratory conditions. It was established on the grounds of an analysis of the obtained results that there is a statistically significant adsorptive power and selectivity of zeolite towards: ammoniac (p<0.01, nitrates (p<0.01, nitrites (p<0.05, and total hardness of water (p<0.05. The applied zeolite contributed to the improvement of the ambient conditions in the trout pond, and it also had a positive ecological effect on the filtration of hydrological toxicants of the pond water output.

  4. Fixed bed adsorption of hexavalent chromium onto natural zeolite from air stream

    Directory of Open Access Journals (Sweden)

    F. Golbabaei

    2014-07-01

    Conclusion: Due to the extensive use of chromium in various industries and regulatory requirements related to workplace health and safety, Cr emission control in the occupational environment is essential. The adsorption process is one of the controlling measures of chromium emissions. The results indicated that natural zeolite has a high efficiency in Cr (VI adsorption.

  5. Effect of zeolite on toxicity of ammonia in freshwater sediments: Implications for toxicity identification evaluation procedures

    Science.gov (United States)

    Besser, J.M.; Ingersoll, C.G.; Leonard, E.N.; Mount, D.R.

    1998-01-01

    Techniques for reducing ammonia toxicity in freshwater sediments were investigated as part of a project to develop toxicity identification and evaluation (TIE) procedures for whole sediments. Although ammonia is a natural constituent of freshwater sediments, pollution can lead to ammonia concentrations that are toxic to benthic invertebrates, and ammonia can also contribute to the toxicity of sediments that contain more persistent contaminants. We investigated the use of amendments of a natural zeolite mineral, clinoptilolite, to reduce concentrations of ammonia in sediment pore water. Zeolites have been widely used for removal of ammonia in water treatment and in aqueous TIE procedures. The addition of granulated zeolite to ammonia-spiked sediments reduced pore-water ammonia concentrations and reduced ammonia toxicity to invertebrates. Amendments of 20% zeolite (v/v) reduced ammonia concentrations in pore water by ???70% in spiked sediments with ammonia concentrations typical of contaminated freshwater sediments. Zeolite amendments reduced toxicity of ammonia-spiked sediments to three taxa of benthic invertebrates (Hyalella azteca, Lumbriculus variegatus, and Chironomus tentans), despite their widely differing sensitivity to ammonia toxicity. In contrast, zeolite amendments did not reduce acute toxicity of sediments containing high concentrations of cadmium or copper or reduce concentrations of these metals in pore waters. These studies suggest that zeolite amendments, used in conjunction with toxicity tests with sensitive taxa such as H. azteca, may be an effective technique for selective reduction of ammonia toxicity in freshwater sediments.

  6. A Laboratory Study of Natural Zeolite for Treatment of Fluorinated Water

    Science.gov (United States)

    Pandey, A.

    2015-12-01

    Fluoride contamination is mainly induced in ground water by chemical interaction between water and fluoride bearing rocks and natural fluoridation is further catalyzed by anthropogenic activities. Elevated fluoride concentrations in the water bodies above the permissible limits are not only degrading water for drinking purposes but also to the agricultural, industrial as well as daily household needs. Fluoride content in water has been constantly a subject of serious concern to the concerned authorities. It is significantly contributing in increasing tolls of arthritis, brain and kidney diseases, cancer, male fertility issues and cases of thyroid diseases. Hence, the present study has been conducted to investigate the possibility of treating fluorinated water using zeolites. The capabilities of natural zeolites are attributed to their catalytic, molecular sieve, adsorption and ion-exchange properties which have been utilized in our laboratory experiment. The experiment was carried out in two phases. In the first phase of the experiment, the properties of zeolites were tested in solid and liquid phases using ICP-OES, SEM, EDX and IC tests. Physio-chemical alterations induced by zeolites in the fluid chemistry were monitored by analyzing fluid sample regularly for pH, redox potential, electrical conductivity and total dissolved solids, and by conducting metal and anion tests. In second phase, zeolite was used for treatment of fluorinated water with known concentration of fluoride, and the geochemical processes associated with fluoride remediation were monitored by conducting non-invasive, invasive geochemical and physical measurements at regular time periods on the water samples collected from both control column and the experiment column. Results thus obtained in this study showed decrease in fluoride concentration over time, indicating the possibility of use of zeolites in treatment of fluorinated water.

  7. Modifications induced by adding natural zeolitic pozzolans to cement paste

    Directory of Open Access Journals (Sweden)

    Blanco-Varela, M. T.

    2005-12-01

    Full Text Available Volcanic pozzolans owe their pozzolanic activity chiefly to the presence of vitreous or zeolitic material rich in SiO2, and Al20y compounds that react with the portlandite produced during cement hydration to generate amorphous gels with cementitious properties. The present study analyzes the modifications taking place in the composition, structure and micro structure of the hydra ted cement paste when 20% of the cement by weight is replaced by two finely ground zeolitic rocks from Cuban deposits. Hydrated cement pastes were prepared with a CEM I35 cement, as well as with mixes of the cement and two Cuban zeolitic rocks (20% by weight. After eight months of hydration, the pastes were characterized -mineralogically, chemically and microstructurally- with XRD, FTIR, 29Si and 27Al MAS NMR, DTA/TG, back scattered electron microscopy and mercury porosimetry techniques. The replacement of 20% by weight of the cement with two finely ground zeolitic rocks significantly modified the composition, structure, quantity and microstructure of the hydrated cement paste reaction product. The C-S-H gel formed in these pastes differed in quantity, which was larger, and composition from the original cement gel. Moreover, the gel formed in addition-free cement had a higher Ca and a lower Al content and shorter silicate chains than the C-S-H product formed in the pastes made with zeolitic rocks. Finally, the pastes with pozzolan additions had fewer and smaller pores.

    La actividad de las puzolanas de origen volcánico procede fundamentalmente de la presencia de material vitreo o zeolítico rico en SiO2 y Al2Oy que son los que reaccionan con la portlandita producida en la hidratación del cemento generando geles amorfos con propiedades cementantes. El objetivo del presente trabajo es estudiar las modificaciones que produce la sustitución del 20% en peso de cemento por dos

  8. ELIMINACIÓN DE COLORANTES CATIÓNICOS USANDO OZONO, ZEOLITA NATURAL Y OZONO/ZEOLITA CATIONIC DYES REMOVAL USING OZONE, NATURAL ZEOLITE, AND OZONE/ZEOLITE

    Directory of Open Access Journals (Sweden)

    Héctor Valdés

    2009-12-01

    Full Text Available En este trabajo se comparan resultados experimentales de remoción azul de metileno (MB utilizando tratamientos basados en la oxidación con ozono (O3, la adsorción con zeolita natural (ZN, y tratamiento simultáneo de adsorción y oxidación con ozono en presencia de zeolita natural (O3/ZN. Se evalúa, a escala de laboratorio, el efecto del pH (2-8 y la presencia de sustancias atrapadoras radicales libres (iones acetatos en la velocidad de remoción y en la eficiencia de los procesos. Los experimentos se realizaron en un reactor diferencial compuesto por un estanque de 1 dm³ y una columna de 19 cm³ de capacidad. El ozono fue generado a razón de 5 g O3/h. Los resultados mostraron que el sistema simultáneo de oxidación/adsorción O3/ZN incrementa la velocidad de remoción del MB con respecto a los procesos separados de ozonización y adsorción con zeolita. En presencia de sustancias atrapadoras de radicales, se observó un 70% de disminución en la velocidad de remoción de MB cuando se empleó el tratamiento con O3 y sólo un 25% cuando se utiliza el tratamiento combinado O3/ZN. Los resultados sugieren que la reacción de oxidación del MB en el sistema tiene lugar fundamentalmente sobre la superficie de la zeolita.This paper compares experimental results on methylene blue (MB removal systems based on ozone oxidation, zeolite adsorption, and simultaneous adsorption-oxidation using ozone in the presence of natural zeolite. The effect of pH (2-8, and the presence of radical scavengers (sodium acetate on process rates and removal efficiencies are assessed at laboratory scale. The experimental system consisted of a 1L differential circular flow reactor and an ozone generator rated at 5 g O3/h. Results show that ozone oxidation combined with zeolite adsorption increases the overall MB oxidation rate with respect to ozonation process and zeolite adsorption. In presence of free radical scavenger, only a 25% of reduction on MB removal rate are

  9. Experimental study on the adsorptive-distillation for dehydration of ethanol-water mixture using natural and synthetic zeolites

    Science.gov (United States)

    Megawati, Wicaksono, D.; Abdullah, M. S.

    2017-03-01

    This research studied adsorptive-distillation (AD) for dehydration of ethanol-water mixture using natural and synthetic zeolites as adsorbent for ethanol purification. Especially, the effect of purification time is recorded and studied to evaluate performance of designed AD equipment. This AD was performed in a batch condition using boiling flask covered with heating mantle and it was maintained at 78°C temperature and 1 atm pressure. The initial ethanol volume was 300 mL with 93.8% v/v concentration. The synthetic zeolite type used was zeolite 3A. The flowed vapour was condensed using water as a cooling medium. Every 5 minutes of time duration the samples were collected until the vapour could not be condensed in that condition and then be analyzed its concentration using Gas-Chromatography. Experiment shows that the designed AD equipment could increase ethanol concentration at first 5 minutes with highest ethanol concentration achieved using synthetic zeolite (97.47% v/v). However, ethanol concentration from AD process using natural zeolite only reached 96.5% v/v. Thus, synthetic zeolite as adsorbent could pass azeotropic point, but natural zeolite fail. The ratio of adsorbed water per adsorbent for natural and synthetic zeolites are about 0.023 and 0.056 gwater/gads, respectively, at 50 minutes of time. Finally, synthetic zeolite (at 55 minutes the value of C/C0 is about 0.85 and the average outlet water concentration is 4.70 mole/L) as adsorbent for AD of ethanol water is better than natural zeolite (at 55 minutes the value of C/C0 is about 0.63 and the average outlet water concentration is 6.43 mole/L).

  10. Treating Coalbed Natural Gas Produced Water for Beneficial Use By MFI Zeolite Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Robert Lee; Liangxiong Li

    2008-03-31

    Desalination of brines produced from oil and gas fields is an attractive option for providing potable water in arid regions. Recent field-testing of subsurface sequestration of carbon dioxide for climate management purposes provides new motivation for optimizing efficacy of oilfield brine desalination: as subsurface reservoirs become used for storing CO{sub 2}, the displaced brines must be managed somehow. However, oilfield brine desalination is not economical at this time because of high costs of synthesizing membranes and the need for sophisticated pretreatments to reduce initial high TDS and to prevent serious fouling of membranes. In addition to these barriers, oil/gas field brines typically contain high concentrations of multivalent counter cations (eg. Ca{sup 2+} and SO{sub 4}{sup 2-}) that can reduce efficacy of reverse osmosis (RO). Development of inorganic membranes with typical characteristics of high strength and stability provide a valuable option to clean produced water for beneficial uses. Zeolite membranes have a well-defined subnanometer pore structure and extreme chemical and mechanical stability, thus showing promising applicability in produced water purification. For example, the MFI-type zeolite membranes with uniform pore size of {approx}0.56 nm can separate ions from aqueous solution through a mechanism of size exclusion and electrostatic repulsion (Donnan exclusion). Such a combination allows zeolite membranes to be unique in separation of both organics and electrolytes from aqueous solutions by a reverse osmosis process, which is of great interest for difficult separations, such as oil-containing produced water purification. The objectives of the project 'Treating Coalbed Natural Gas Produced Water for Beneficial Use by MFI Zeolite Membranes' are: (1) to conduct extensive fundamental investigations and understand the mechanism of the RO process on zeolite membranes and factors determining the membrane performance, (2) to improve

  11. Long-Term Properties of Cement-Based Composites Incorporating Natural Zeolite as a Feature of Progressive Building Material

    Directory of Open Access Journals (Sweden)

    Alena Sičáková

    2017-01-01

    Full Text Available This study is aimed at the utilization of natural zeolite as a prospective type of Supplementary Cementitious Material in connection with the innovations of construction solutions through the materials. The influence of zeolite on several properties of cement-based composites is studied. Basic characteristics of input powdery materials as well as the technological parameters of zeolite tested on mortar containing 50% of cement replacement are presented. The technical parameters of concrete containing 8, 13, and 25% of cement replacement by zeolite are presented as well. The paper is valuable due to the three-year testing period. The density of the hardened concrete was found to be decreasing with increasing zeolite content. While no significant differences in compressive strength were found after 28 days, differences between individual samples were clear after the long-term period. The presence of zeolite influenced the compressive strength positively in the case of the 8% and 13% replacement, while the higher proportion of natural zeolite (25% caused lower compressive strength after 28 days but was similar to the reference concrete after three years. A major increase in strength was detected for all samples in the long-term period. It confirms the long-term potential of zeolite for strength improvement.

  12. PREPARATION, CHARACTERIZATION, AND CATALYTIC ACTIVITY TEST OF Ni-Mo/NATURAL ZEOLITE ON PYRIDINE HYDRODENITROGENATION

    Directory of Open Access Journals (Sweden)

    Sri Kadarwati

    2010-12-01

    Full Text Available Preparation, characterization, and catalytic activity test of Ni-Mo/natural zeolite on pyridine hydrodenitrogenation were carried out. Preparation of catalyst was conducted by impregnation method using nickel nitrate hexahydrate and ammonium heptamolibdate precursor as Ni and Mo source respectively. Characterization of catalyst was conducted by using gravimetry, atomic absorption spectrophotometry, and X-ray diffraction method. Catalytic activity test on pyridine hydrodenitrogenation was carried out by using flow system reactor with hydrogen flow rate variable. The research results showed that the catalyst's total acidity and crystallinity are increased with level of impregnation success of 96.71% and 90.08% respectively. Ni-Mo/natural zeolites able to increase the catalytic conversion up to 71.78% at 350 °C and hydrogen flow rate of 10 mL/min with more highly varied product distribution. Assuming that the pyridine hydrodenitrogenation follows the pseudo first order kinetics.

  13. Trading quality and breadmaking performance of wheat treated with natural zeolite and diatomaceous earth

    Directory of Open Access Journals (Sweden)

    Bodroža-Solarov Marija I.

    2011-01-01

    Full Text Available The aim of study was to investigate the influence of naturally occurring zeolite and diatomaceous earth, as inert dusts approved for insect pest control in certified organic crop production, on trading and breadmaking quality of treated wheat. The treatments significantly reduced the trading quality of wheat which was reflected through lowering of test weight. This effect was more marked in the case of low-vitreous wheat rather than in high-vitreous one. Investigation of rheological properties of flours made from the treated wheat demonstrated that treatments with natural zeolite and diatomaceous earth at all applied doses significantly increased the water absorption, which consequently increased the bread yield. However, these changes in the flour properties were not high enough to modify the quality attributes of bread as was shown by instrumentally measuring crumb hardness and springiness as well as sensory evaluation.

  14. Synthesis of biodiesel using local natural zeolite as heterogeneous anion exchange catalyst

    Science.gov (United States)

    Hartono, R.; Wijanarko, A.; Hermansyah, H.

    2018-04-01

    Production of biodiesel using homogen catalyst: alkaline catalysts, acid catalysts, biocatalysts, and supercritical methanol are very inefficient, because these catalysts have a very high cost production of biodiesel and non-ecofriendly. The heterogeneous catalyst is then used to avoid adverse reaction of biodiesel production. The heterogeneous catalysts used is ion exchanger using natural zeolit catalists bayah banten (ZABBrht) and macroporous lewatit that can be used to produce biodiesel in the solid phase so that the separation is easier and can be used repeatedly. The results of biodiesel reach its optimum in engineering ion exchange catalyst natural zeolit bayah and macroporous lewatit which has been impregnated and calcinated at temperature 60 °C at reaction time 2 hours, are 94.8% and 95.24%, using 100 gr.KOH/100 mL Aquadest.

  15. Ammonium ion interaction with conditioned natural zeolite with silver and its effect on the disinfection of polluted water in front of a consortium of gram (+) and gram (-) microorganisms; Interaccion del ion amonio con zeolita natural acondicionada con plata y su efecto sobre la desinfeccion de agua contaminada frente a un consorcio de microorganismos gram (+) y gram (-)

    Energy Technology Data Exchange (ETDEWEB)

    Gonzaga G, V. E.

    2013-07-01

    Clinoptilolite zeolite material is a relative abundance in Mexico, which has ion exchange properties, therefore, has the ability to retain metal ions giving it an application in the process of disinfecting of water contaminated with pathogenic microorganisms. In this research, we conducted a study of disinfection of water contaminated with a microbial consortium, from a zeolite rock clinoptilolite from a deposit located in the State of Guerrero. Initially, the zeolite prepared by the grinding and sieving, for conditioning with NaCl and subsequently with AgNO{sub 3}, finally to be characterized using the techniques of scanning electron microscopy and X-ray diffraction. Tests using columns packed with zeolite material, the effect of zeolite bactericidal conditioned with silver (ZGAg) against a microbial consortium consisting of Escherichia coli and Sthapyloccocus aureus in aqueous solution in the presence of ammonium ions used to increase the ion exchange with zeolite fitted with silver. To describe curves disinfecting a continuous flow system is adapted Gu pta model, which describes the kinetics and equilibrium adsorption process, considering the microorganisms as the adsorbate and the sanitizing agent (conditioned with silver zeolite) as the adsorbent. Characterization results show that in the scanning electron microscopy (Sem), no changes were obtained on the morphology of typical clinoptilolite crystals before and after that was modified with sodium and then with silver, it is worth mentioning however that fitted with silver zeolite (ZGAg), small particles are seen on the zeolite material which when analyzed by energy dispersive spectroscopy (EDS), we found a high concentration of Ag +. The disinfection period is increased as the concentration increased ammonium ions, this behavior is attributed to the ion exchange that occurs between the ammonium ions and silver ions. A lower percentage of inactivation is due, therefore, to a lesser amount of money available to

  16. Solid-liquid-solid extraction of heavy metals (Cr, Cu, Cd, Ni and Pb) in aqueous systems of zeolite-sewage sludge

    International Nuclear Information System (INIS)

    Sprynskyy, Myroslav

    2009-01-01

    This paper presents results of kinetic and equilibrium studies of the removal of heavy metals (Cr, Cu, Cd, Ni and Pb) from the sewage sludge using a new technique of solid-liquid-solid extraction with the adsorption-diffusion column filled by the zeolite. The metal extraction onto the zeolite from aqueous solution of the clinoptilolite and the sludge composition is characterized by three stages: intensive extraction, inversion and stabilization with the moderate extraction increase. Addition of 25% of the zeolite provides extraction efficiency of cadmium and lead of about 84%, chromium, copper and nickel of 66%, 61% and 50%, respectively. The estimated values of Gibbs free energy change ΔG show that the metals extraction by the clinoptilolite may be considered as a physical adsorption. The negative values of ΔG testify to an exothermic nature of the process. The difference between energetic potentials of the components is a driving force of the metal redistribution in the system 'clinoptilolite-water-sludge'

  17. Liquid and Gaseous Fuel from Waste Plastics by Sequential Pyrolysis and Catalytic Reforming Processes over Indonesian Natural Zeolite Catalysts

    Directory of Open Access Journals (Sweden)

    Mochamad Syamsiro

    2014-08-01

    Full Text Available In this study, the performance of several differently treated natural zeolites in a sequential pyrolysis and catalytic reforming of plastic materials i.e. polypropylene (PP and polystyrene (PS were investigated. The experiments were carried out on two stage reactor using semi-batch system. The samples were degraded at 500°C in the pyrolysis reactor and then reformed at 450°C in the catalytic reformer. The results show that the mordenite-type natural zeolites could be used as efficient catalysts for the conversion of PP and PS into liquid and gaseous fuel. The treatment of natural zeolites in HCl solution showed an increase of the surface area and the Si/Al ratio while nickel impregnation increased the activity of catalyst. As a result, liquid product was reduced while gaseous product was increased. For PP, the fraction of gasoline (C5-C12 increased in the presence of catalysts. Natural zeolite catalysts could also be used to decrease the heavy oil fraction (>C20. The gaseous products were found that propene was dominated in all conditions. For PS, propane and propene were the main components of gases in the presence of nickel impregnated natural zeolite catalyst. Propene was dominated in pyrolysis over natural zeolite catalyst. The high quality of gaseous product can be used as a fuel either for driving gas engines or for dual-fuel diesel engine.

  18. THE EFFECT OF AMOUNT OF NATURAL ZEOLIT CATALYST IN PRODUCT OF POLYPROPILENE (PP PLASTIC WASTE PYROLYSIS

    Directory of Open Access Journals (Sweden)

    khalimatus sa'diyah

    2015-12-01

    Full Text Available To overcome the waste problem, especially plastic waste , environmental concerned scientists from various disciplines have conducted various research and actions. Catalytic pyrolysis processes was chosen as an alternative method to recycle plastic waste. The purpose of this experiment was to determine the effect of natural zeolit catalyst on the pyrolysis process with oxygen-free conditions to obtain maximum hydrocarbon compounds (gasoline fraction in C5-C9. The process of pyrolysis was conducted in 3.5 dm3 unstirred stainless steel semi-batch reactor. This process operated at atmospheric pressure with nitrogen injection. Plastic waste that used in this particular paper was 50 grams of polypropylene (PP. In pyrolysis process, natural zeolite catalysts was added 2,5 gram (5% weight of natural zeolite per weight of plastic waste samples, 5 gram (10% , and 10 gram (20%. Temperature of pyrolysis was 450°C and were maintained until 30 minutes. Steam that produced from pyrolisis was condensed and analysed by gas chromatography–mass spectrometry (GC-MS to determine yield of hydrocarbons produced. From the analysis of GC-MS, liquid products of pyrolysis contained lots of aromatic hydrocarbons. The optimal amount of catalyst that produce liquid with hydrocarbon compound that has the quality of gasoline was 10 gram (20% with ≤C9 composition as 29,16% n-paraffin, 9,22% cycloparaffin, and 61,64% aromatics.

  19. A Prebiotic Chemistry Experiment on the Adsorption of Nucleic Acids Bases onto a Natural Zeolite.

    Science.gov (United States)

    Anizelli, Pedro R; Baú, João Paulo T; Gomes, Frederico P; da Costa, Antonio Carlos S; Carneiro, Cristine E A; Zaia, Cássia Thaïs B V; Zaia, Dimas A M

    2015-09-01

    There are currently few mechanisms that can explain how nucleic acid bases were synthesized, concentrated from dilute solutions, and/or protected against degradation by UV radiation or hydrolysis on the prebiotic Earth. A natural zeolite exhibited the potential to adsorb adenine, cytosine, thymine, and uracil over a range of pH, with greater adsorption of adenine and cytosine at acidic pH. Adsorption of all nucleic acid bases was decreased in artificial seawater compared to water, likely due to cation complexation. Furthermore, adsorption of adenine appeared to protect natural zeolite from thermal degradation. The C=O groups from thymine, cytosine and uracil appeared to assist the dissolution of the mineral while the NH2 group from adenine had no effect. As shown by FT-IR spectroscopy, adenine interacted with a natural zeolite through the NH2 group, and cytosine through the C=O group. A pseudo-second-order model best described the kinetics of adenine adsorption, which occurred faster in artificial seawaters.

  20. The role of natural zeolite and of zeolite modified with ammnonium ions to reduce the uptake of lead, zinc, copper and iron ions in Hieracium aurantium and Rumex acetosella grown on tailing ponds

    Directory of Open Access Journals (Sweden)

    Anca PETER

    2011-11-01

    Full Text Available The objective of this research is to determine if zeolite modified with ammonium ions has a higher capacity than natural zeolite to protect Hieracium aurantium and Rumex acetosella growing on tailing ponds, by reducing the quantity of metal ions these plants would accumulate in their roots and leaves. The influence of the amount of zeolite in the substrate (5% and 10% mass percentage was also studied. The experiments were carried out in laboratory and the concentration of the ions of heavy metal in roots and leaves, after 38 days of growth was established by Flame Atomic Adsorption Spectroscopy. The pH, conductivity and redox potential for each of the substrate considered were measured. The results were statistically processed using the one-way analysis of variance (one-way ANOVA. FTIR analyses were performed to establish the structural differences between the natural and modified zeolite. Hieracium aurantium and Rumex acetosella accumulate a smaller quantity of metal ions in roots and leaves in the presence of zeolite modified with ammonium ions than in the presence of natural zeolite. Laboratory tests showed that Hieracium aurantium is more tolerant to ions of heavy metals than Rumex acetosella, as demonstrated by their translocation factors.In terms of reducing the uptake of ions of heavy metals, only the zeolite modified with ammonium has a significant protective effecton Hieracium aurantium, while both natural zeolite and zeolite modified demonstrate a significant role for Rumex acetosella, asrevealed by statistical tests.

  1. Plastic waste to liquid oil through catalytic pyrolysis using natural and synthetic zeolite catalysts.

    Science.gov (United States)

    Miandad, R; Barakat, M A; Rehan, M; Aburiazaiza, A S; Ismail, I M I; Nizami, A S

    2017-11-01

    This study aims to examine the catalytic pyrolysis of various plastic wastes in the presence of natural and synthetic zeolite catalysts. A small pilot scale reactor was commissioned to carry out the catalytic pyrolysis of polystyrene (PS), polypropylene (PP), polyethylene (PE) and their mixtures in different ratios at 450°C and 75min. PS plastic waste resulted in the highest liquid oil yield of 54% using natural zeolite and 50% using synthetic zeolite catalysts. Mixing of PS with other plastic wastes lowered the liquid oil yield whereas all mixtures of PP and PE resulted in higher liquid oil yield than the individual plastic feedstocks using both catalysts. The GC-MS analysis revealed that the pyrolysis liquid oils from all samples mainly consisted of aromatic hydrocarbons with a few aliphatic hydrocarbon compounds. The types and amounts of different compounds present in liquid oils vary with some common compounds such as styrene, ethylbenzene, benzene, azulene, naphthalene, and toluene. The FT-IR data also confirmed that liquid oil contained mostly aromatic compounds with some alkanes, alkenes and small amounts of phenol group. The produced liquid oils have high heating values (HHV) of 40.2-45MJ/kg, which are similar to conventional diesel. The liquid oil has potential to be used as an alternative source of energy or fuel production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Experimental Study on Pressure Drop and Flow Dispersion in Packed Bed of Natural Zeolite

    Directory of Open Access Journals (Sweden)

    Ruya Petric Marc

    2018-01-01

    Full Text Available The use of conventional correlation for pressure drop and dispersion coefficient calculation may result in inaccurate values for zeolite packed bed as the correlations are generally developed for regularly shaped and uniformly sized particles. To support the research on the application of modified natural zeolite as tar cracking catalyst, the research on the hydrodynamic behaviour of zeolite packed bed has been conducted. Experiments were carried out using a glass column with diameter of 37.8 mm. Natural zeolite with particle size of about 2.91 to 6.4 mm was applied as packing material in the column, and the bed height was varied at 9, 19 and 29 cm. Air was used as the fluid that flows through the bed and nitrogen was used as a tracer for residence time distribution determination. Air flow rates were in the range of 20 to 100 mL/s which correspond to the laminar-transitional flow regime. The pressure drops through the bed were in the range of 1.7 to 95.6 Pa, depending on the air flow rate and bed height. From these values, the parameters in the Ergun equation were estimated, taking into account the contribution by wall effect when the ratio of column to particle diameter is low. The viscous and inertial term constants in the Ergun equation calculated ranges from 179 to 199 and 1.41 to 1.47 respectively while the particle sphericity ranges from 0.56 to 0.59. The reactor Peclet number were determined to range from 5.2 to 5.5, which indicated significant deviation from a plug flow condition.

  3. Cd(II Sorption on Iranian nano zeolites: Kinetic and Thermodynamic Studies

    Directory of Open Access Journals (Sweden)

    Taher Yousefi

    2016-11-01

    Full Text Available An uptake of Cd(II from aqueous solutions by ion exchange on Iranian natural zeolitic (TOSKA has been studied. Experiments were carried out using batch method as a function of the initial concentration of metal ions, contact time, and temperature. The adsorbent is characterized using XRF, FTIR, TEM, and XRD. The TEM images showed that the zeolite particle sizes are reduced into the size range of less than 90 nm by means of ball milling. The characterization of sample indicates that the natural zeolite used in this study was classified into clinoptilolite. Equilibrium modelling data were fitted to linear Langmuir and Freundlich models. Thermodynamics parameters such as change in free energy (ΔG◦, enthalpy (ΔH◦ and entropy (ΔS◦ were also calculated. The negative values obtained for ΔG◦ indicated that the sorption of Cd(II on natural zeolite was spontaneous at all studied concentrations. These results show that natural zeolites hold great potential to remove Cd(II from industrial wastewater.

  4. Uptake of Cd(II Using Natural Zeolite: Batch and Continuous Fixed-Bed Studies

    Directory of Open Access Journals (Sweden)

    Luna M. LMarashdeh

    2009-12-01

    Full Text Available Uptake of Cd(II ions by natural phillipsite tuff was investigated both in shake-flask and fixed-bed columns. Equilibrium uptake, qe, was found to best fit Langmuir adsorption isotherm with a maximum value of 25.78 mg/g. Percent removal of Cd ions was close to 100% from initial metal ion concentrations in the range 50 - 75 mg/L at 5.0 g zeolite/L. Also, qe was found to vary exponentially with zeolite dose. Break points as high as 350 minutes were obtained from bed treatment at favorable conditions of a low solution flow rate and high bed depth. In batch experiments, equilibrium pH increased to < 8.0 excluding chemical precipitation as part of the removal while in fixed-beds the final pH exceeded 9.0. It is suggested that a sieve action of zeolite porous structure plays a role as an uptake mechanism in addition to the ion exchange.

  5. Obtaining and preliminary structural characterization of membranes of zeolite through the PLD technique

    International Nuclear Information System (INIS)

    Concepción-Rosabal, B.; Rodríguez-Iznaga, I.; Rodríguez, E.; Pentón-Madrigal, A.

    2008-01-01

    Full text: This paper presents the preliminary results of the obtaining of membranes of natural zeolites exchanged with metal species through the P ulsed Laser technique Deposition ( PLD). The ultimate goal of this work is to obtain membranes zeolite that can serve as matrices or different species (nanoparticles) supports Active stable and controlled environment release. This material is oriented to biomedical applications. The microbiocidal effect of zeolites containing ion or metallic nanoparticles with oligodynamic properties is widely reported in the literature. The material used zeolitic was purified natural clinoptilolite, NZ Site Tasajeras (Villa Clara, Cuba), which is a mixture of around 70% of clinoptilolite heulandita, and mordenite and 30% of other phases (feldspars, quartz). Ag-clinoptilolite and Feclinoptilota were obtained from the audio Exchange NZ natural zeolite with solutions of silver nitrate and sulphate of iron (II) respectively. The experimental arrangement used for the manufacture of the thin films of NZ consists of a vacuum chamber pumped up to a final pressure of - 1 x 10 - 7 mbar with a pump turbo molecular. Zeolite ablation was performed in atmosphere of Argon of high purity, using the second harmonic of a Quantel Brillant Nd: YAG laser (532nm, 4ns, 20 Hz) Q-Switch contract.) Pulse energy, measured at the surface of the target was 80 MJ, resulting in a yield of 20 J / cm2. The laser beam was focused with a lens of 30 cm of focus at 45° incidence on the target surface. The target was rotated during growth to prevent irradiation of the same area. The distance white glass substrate was maintained at 5 cm. The flow of Argon in the Chamber was regulated through a driver Shimadzu FC-40, keeping constant pressure of the Argon 0.5 mbar during growth. To improve the cleaning of the surface of the substrate and consequently the adhesion of the film in the same East was subjected to an initial treatment of RF. Preliminary analysis by diffraction

  6. Effects of aeration and natural zeolite on ammonium removal during the treatment of sewage by mesocosm-scale constructed wetlands.

    Science.gov (United States)

    Araya, F; Vera, I; Sáez, K; Vidal, G

    2016-01-01

    The objective was to evaluate the effects of intermittent artificial aeration cycles and natural zeolite as a support medium, in addition to the contribution of plants (Schoenoplectus californicus) on NH4(+)-N removal during sewage treatment by Constructed Wetlands (CW). Two lines of Mesocosm Constructed Wetland (MCW) were installed: (a) gravel line (i.e. G-Line) and (b) zeolite line (i.e. Z-Line). Aeration increased the NH4(+)-N removal efficiency by 20-45% in the G-Line. Natural zeolite increased the NH4(+)-N removal efficiency by up to 60% in the Z-Line. Plants contributed 15-30% of the NH4(+)-N removal efficiency and no difference between the G-Line and the Z-Line. Conversely, the NH4(+)-N removal rate was shown to only increase with the use of natural zeolite. However, the MCW with natural zeolite, the NH4(+)-N removal rate showed a direct relationship only with the NH4(+)-N influent concentration. Additionally, relationship between the oxygen, energy and area regarding the NH4(+)-N removal efficiency was established for 2.5-12.5 gO2/(kWh-m(2)) in the G-Line and 0.1-2.6 gO2/(kWh-m(2)) in the Z-Line. Finally, it was established that a combination of natural zeolite as a support medium and the aeration strategy in a single CW could regenerate the zeolite's adsorption sites and maintain a given NH4(+)-N removal efficiency over time.

  7. Removal of Pb(II) from water by natural zeolitic tuff: Kinetics and thermodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Karatas, Mustafa, E-mail: mkaratas33@gmail.com [Aksaray University, Engineering Faculty, Department of Environmental Engineering, 68100 Aksaray (Turkey)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer Volcanic tuff is a natural zeolitic mineral. Black-Right-Pointing-Pointer It could help to remediate, to control or to prevent a possible pollution of water by lead. Black-Right-Pointing-Pointer Physicochemical interactions occur between lead cations and volcanic tuff particles in aqueous solution Black-Right-Pointing-Pointer Adsorption process follows second-order reaction kinetics and Langmuir adsorption isotherm adsorption process spontaneous and exothermic under natural conditions. - Abstract: The present study was aimed at examining the ability of a natural zeolitic volcanic tuff to remove Pb(II) ions from aqueous solutions under various conditions. The effects of various parameters such as optimum adsorbent mass, contact time, pH of the medium, Pb(II) concentration, and temperature were investigated. In addition, different adsorption isotherms were obtained using concentrations of Pb(II) ions ranging from 1 mg/L to 200 mg/L. The adsorption process follows second-order reaction kinetics and follows the Langmuir adsorption isotherm. The thermodynamic parameters are discussed in this article, including changes in Gibbs free energy, entropy, and enthalpy, for the adsorption of Pb(II) on tuff, and it is revealed that the adsorption process was spontaneous and exothermic under natural conditions. The maximum removal efficiency of 92% was obtained at a pH of 5 with a 25-min contact time for a 10 g/L solid-to-liquid ratio and an initial heavy metal concentration of 100 mg/L.

  8. The influence of using Jordanian natural zeolite on the adsorption, physical, and mechanical properties of geopolymers products.

    Science.gov (United States)

    Yousef, Rushdi Ibrahim; El-Eswed, Bassam; Alshaaer, Mazen; Khalili, Fawwaz; Khoury, Hani

    2009-06-15

    Geopolymers consist of an amorphous, three-dimensional structure resulting from the polymerization of aluminosilicate monomers that result from dissolution of kaolin in an alkaline solution at temperatures around 80 degrees C. One potential use of geopolymers is as Portland cement replacement. It will be of great importance to provide a geopolymer with suitable mechanical properties for the purpose of water storage and high adsorption capacity towards pollutants. The aim of this work is to investigate the effect of using Jordanian zeolitic tuff as filler on the mechanical performance and on the adsorption capacity of the geopolymers products. Jordanian zeolitic tuff is inexpensive and is known to have high adsorption capacity. The results confirmed that this natural zeolitic tuff can be used as a filler of stable geopolymers with high mechanical properties and high adsorption capacity towards methylene blue and Cu(II) ions. The XRD measurements showed that the phillipsite peaks (major mineral constituent of Jordanian zeolite) were disappeared upon geopolymerization. The zeolite-based geopolymers revealed high compressive strength compared to reference geopolymers that employ sand as filler. Adsorption experiments showed that among different geopolymers prepared, the zeolite-based geopolymers have the highest adsorption capacity towards methylene blue and copper(II) ions.

  9. Modeling of the adsorption kinetics of zinc onto granular activated carbon and natural zeolite

    Directory of Open Access Journals (Sweden)

    VERA D. MESHKO

    2006-09-01

    Full Text Available The isotherms and kinetics of zinc adsorption from aqueous solution onto granular activated carbon (GAC and natural zeolite were studied using an agitated batch adsorber. The maximum adsorption capacities of GAC and natural zeolite towards zinc(II from Langmuir adsorption isotherms were determined using experimental adsorption equilibrium data. The homogeneous solid diffusion model (HSD-model combined with external mass transfer resistance was applied to fit the experimental kinetic data. The kinetics simulation study was performed using a computer program based on the proposed mathematical model and developed using gPROMS. As the two-mass transfer resistance approach was applied, twomodel parameters were fitted during the simulation study. External mass transfer and solid phase diffusion coefficients were obtained to predict the kinetic curves for varying initial Zn(II concentration at constant agitation speed and constant adsorbent mass. For any particular Zn(II – adsorbent system, kf was constant, except for the lowest initial concentration, while Ds was found to increase with increasing initial Zn(II concentration.

  10. Biodiesel production from rice bran oil by transesterification using heterogeneous catalyst natural zeolite modified with K2CO3

    Science.gov (United States)

    Taslim; Iriany; Bani, O.; Parinduri, S. Z. D. M.; Ningsih, P. R. W.

    2018-02-01

    In the present study, an effort had been made to use natural zeolite from Tapanuli Utara, North Sumatera as a potential catalyst for biodiesel production. Biodiesel production is usuallythrough transesterification, and a catalyst is employed to improve reaction rate and yield. In this research rice bran oil (RBO) was used as feedstock. The objective of this work was to discover the effectiveness of natural zeolite modified by K2CO3 as catalysts in biodiesel production from RBO. K2CO3/natural zeolite catalyst modification was by impregnation method at various K2CO3 concentrations followed by drying and calcination. Transesterification was conducted at 65°C and 500 rpm. Effect of process variables such as the amount of catalyst, reaction time, and the molar ratio of methanol to RBO was investigated.The maximum yield of 98.18% biodiesel was obtained by using 10:1 molar ratio of methanol to RBO at a reaction time of 3 hours in the presence of 4 w% catalyst. The obtained biodiesel was then characterized by its density, viscosity and ester content. The biodiesel properties met the Indonesia standard (SNI).The results showed that natural zeolite modified by K2CO3 was suitable as a catalyst in the synthesis of biodiesel through transesterification from RBO.

  11. Catalytic Activities of Fe3+- and Zn2+-Natural Zeolite on the Direct Cyclisation-Acetylation of (R-(+-Citronellal

    Directory of Open Access Journals (Sweden)

    Edy Cahyono

    2014-07-01

    Full Text Available Characterisation and catalytic ativities investigation of modified natural zeolite on cyclisation acetylation reaction of (R-(+-citronellal was performed. The experimental work involved isolation of (R-(+-citronellal from Java Citronella oil (Cymbopogon winterianus by vacuum fractional distillation, determination of its enantiomer, preparation and characterisation of different catalysts i.e. H-natural zeolite (H-Za, Fe3+-natural zeolite (Fe3+-Za, and Zn2+-natural zeolite (Zn2+-Za, followed by examination of catalytic activity and selectivity. Isolated citronellal contained 88.21% ee of (R-(+-citronellal. The main products of cyclisation-acetylation of (R-(+-citronellal was IPA (isopulegyl acetate and NIPA (neo-isopulegyl acetate. Although the highest yield of IPA and NIPA was obtained by Fe3+-Za catalyst (78.69% at 80oC and 120 min, the stereoselectivity of Fe3+-Za slightly lower than that of Zn2+-Za. Structure elucidation of citronellal and products was carried out by means of GC and GC-MS. Lewis acidity plays the role of acetyl ionic formation from acetic anhydride. The Activity and stereoselectivity of catalysts depended on Lewis acidity and cation distribution on the catalyst surface. © 2014 BCREC UNDIP. All rights reservedReceived: 18th December 2013; Revised: 9th April 2014; Accepted: 17th April 2014[ How to Cite: Cahyono, E., Muchalal, M., Triyono, T., Pranowo, H.D. (2014. Catalytic Activities of Fe3+- and Zn2+-Natural Zeolite on the Direct Cyclisation-Acetylation of (R-(+-Citronellal. Bulletin of Chemical Reaction Engineering & Catalysis, 9 (2: 128-135. (doi:10.9767/bcrec.9.2.5936.128-135 ][ Permalink/DOI: http://dx.doi.org/10.9767/bcrec.9.2.5936.128-135 ] 

  12. Laser-induced breakdown spectroscopy for the quantitative analysis of metals in sediments using natural zeolite matrix

    Science.gov (United States)

    Austria, E. S.; Fuentes, E. M.; Nuesca, G. M.; Lamorena, R. B.

    2017-10-01

    The dependence of laser-induced breakdown spectroscopy (LIBS) to the matrix of the sample remains an important consideration in performing quantitative analysis. In this study, a new matrix was introduced in the preparation of solid powder calibration curves. Heat-treated natural zeolite and KBr were mixed separately into high purity metal powders to generate calibration curves using a univariate approach. A LIBS technique was used in the detection and quantitative analysis of Cr, Cu and Pb in river sediment samples. The relative percent difference (RPD) was calculated to describe the variability measurements made using ICP/OES and LIBS as well as to evaluate the accuracy of the method. Calculated limits of detection in the matrices prepared were comparable with literature values and ranged from 0.41 to 6.1 ppm. The resulting metal concentrations indicate that the natural zeolite matrix were closer to the reference values compared to the KBr matrix. By employing principal component analysis (PCA), heat treated zeolite was shown as a potential diluent or binder for generating calibration curves and could provide matrix-matched standards in identification of target metals from unknown sediment samples. The natural zeolite appeared to closely simulate the ablation behavior and property of the samples, and it is found to be a potential suitable matrix for the quantitative LIBS analysis of sediments.

  13. Proposal of the system for the biogas purification using vitreous and natural zeolite membranes

    International Nuclear Information System (INIS)

    Ortega Viera, Lianys; Fernández SantanI, Elina; Alfonso Martínez, Félix Enrique; Aguiar RoqueI, Yania; Rodríguez Muñoz, Susana

    2017-01-01

    One way to reduce the effects of climate change is to replace fossil fuels with renewable energy such as biogas, but the amount of hydrogen sulphide in it represents an impediment to its use, because of its negative impacts on human health, materials of construction and the environment, being essential its reduction or elimination. For this reason, it was defined as aim to propose an effective method for the purification of biogas using membranes constructed from vitreous waste materials and natural cuban zeolite. This treatment requires four membranes with their supports and eight valves and could be used by small farmers for the purification of 1.4 m 3 of biogas per day, an amount necessary for the cooking of three meals of a family of five people, being the cost of the biogas purification process equal to 0.06%/m 3 . (author)

  14. Arsenic adsorption in pre-treatment natural zeolite with magnesium oxides

    International Nuclear Information System (INIS)

    Mejia Z, F.; Valenzuela G, J. L.; Aguayo S, S.; Meza F, D.

    2009-01-01

    A methodology was developed to modify a natural zeolite (chabazite) with magnesium oxide in order to remove arsenic (As +5 ) from water for human consumption. It is proposed a magnesium oxide while regarded as an efficient adsorbent for removing metals in water. X-ray diffraction analyses show significant changes in the chabazite due to the presence of oxides and amorphous hydroxides incorporated during the pre-treatment. Experimental design results show an efficiency greater than 90% of As +5 adsorbed in five minutes. The results indicate that the most significant variables affecting the adsorption of As +5 are the initial concentration of As and the solid/liquid ratio. Experimental data fitted better to Freundlich isotherm with a 20.17 mg/g adsorption capability. (Author)

  15. The nature of the process of alkylation of isobutane by butenes in zeolite catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Patrilyak, K.I.; Bayburskiy, V.L.; Bortyshevskiy, V.A.; Galich, P.N.; Gutyrya, V.S.; Manza, I.A.

    1983-01-01

    The change in the concentration of butenes is studied in a reaction of alkylation of isobutane by butenes in a zeolite catalyst (Kt) in individual zones of a reactor relative to the length of the process. It is shown that the system is characterized by the presence of a period of development of the catalyst, whose length is a function of the conditions of catalyst activation and is from 15 to 20 minutes to 1 hour. Isomerization of butene-1 into butene-2 is discovered. It is shown that the most obvious isomerization is expressed for a catalyst sample active in nonoptimal conditions. The change in the concentration of the butenes in time in individual zones of the catalyst has a wavy nature.

  16. In vitro and in vivo efficiency of clinoptilolite in 137Cs binding

    International Nuclear Information System (INIS)

    Vitorovic, D.; Vitorovic, G.; Mladenovic, V.; Vukicevic, O.

    1998-01-01

    The results of investigation of the sorption of micro amounts of 137 Cs on powdered clinoptilolite in an electrolyte similar to the stomach content of animals are presented. The experiments were performed with the natural form of clinoptilolite from the Zlatopek mine (Vranjska Banja) and with the sodium form at 37 deg C. Simultaneously, investigation was made into the efficiency of the natural form of clinoptilolite in the radioprotection of chicks alimentary contaminated with 1 37 Cs. Clinoptilolite showed a high efficiency in 137 Cs sorption from the electrolyte solution, where 96-98% of initial activity was sorbed. Protection effect in chicks alimentary contaminated with 137 Cs, measured 3 and 7 hours after the contamination, was approximately 75% for the meat and edible inner organs of the chicks

  17. THE STUDY OF THE KINETIC OF NATURAL ZEOLITE GRANULES GROWTH AT DIFFERENT WAYS OF GRANULATION

    Directory of Open Access Journals (Sweden)

    Rybachuk VD

    2016-12-01

    Full Text Available Introduction. Active substances and excipients used in the manufacture of medicines in tablet form, in most cases, have poor technological properties. This fact determines the need for prior granulation of mass before compression. Granulators of various sizes and designs, running on different modes, made the formation, growth and consolidation of the powder particles that lead to obtain pellets of different shapes and sizes. From the literature it is known that granulation leads to two forms of granules: isodiametric and nonisodiametric. The first group of particles forms has globular shape with a smooth surface and the proportion in which the length, thickness and height are about the same. They are usually made by fluidized bed granulation, spray drying, pelletizing and granulation in dragee pan. Granules of nonisodiametric form in which length is several times the width and height are made mostly by extrusion and compacting. The geometrical parameters of obtained granules are affected by the properties of raw materials, the granulation modes, type and amount of added humidifier and so on. The shape and size of granules, from a technological point of view, are the key factors that contribute, except organoleptic characteristics of the product, its technological properties such as particle size distribution, bulk volume, the ability of the material to shrinkage, porosity, fluidity, mechanical strength and so on. Properly selected for specific conditions granulation method is able to provide the finished product with the specified technological parameters depending on the needs. The aim of this work was to study the effect of granulation method and its conditions on the kinetics of growth of the natural zeolite granules and some quality characteristics of obtained granules. Material & methods. As objects of study served the natural zeolite pellets produced using 3%, 5%, 7% and 10% potato starch paste and solution of polyvinylpyrrolidone (PVP

  18. Templating mesoporous zeolites

    DEFF Research Database (Denmark)

    Egeblad, Kresten; Christensen, Christina Hviid; Kustova, Marina

    2008-01-01

    The application of templating methods to produce zeolite materials with hierarchical bi- or trimodal pore size distributions is reviewed with emphasis on mesoporous materials. Hierarchical zeolite materials are categorized into three distinctly different types of materials: hierarchical zeolite...... originates almost exclusively from the support material. The methods for introducing mesopores into zeolite materials are discussed and categorized. In general, mesopores can be templated in zeolite materials by use of solid templating, supramolecular templating, or indirect templating....... In this categorization of templating methods, the nature of the interface between the zeolite crystal and the mesopore exactly when the mesopore starts to form is emphasized. In solid templating, the zeolite crystal is in intimate contact with a solid material that is being removed to produce the mesoporosity. Similarly...

  19. A comprehensive study on photocatalytic activity of supported Ni/Pb sulfide and oxide systems onto natural zeolite nanoparticles

    International Nuclear Information System (INIS)

    Babaahamdi-Milani, Majid; Nezamzadeh-Ejhieh, Alireza

    2016-01-01

    Highlights: • Increase in photocatalytic activity of hybridized/supported PbO/NiO and PbS/NiS systems with respect to semiconductors alone. • Higher efficiency of PbO/NiO than PbS/NiS. • Positive role of p-n junction for enhancement of photocatalytic activity of the used semiconductors. - Abstract: The Ni(II)-Pb(II) exchanged clinoptilolite nanoparticles (NCP) were transformed to corresponding oxides and sulfides via calcination and sulfiding processes, respectively. The obtained catalysts were characterized by XRD, FT-IR, TEM and DRS and used in photodegradation of p-nitrophenol (4-NP) aqueous solution under Hg-lamp irradiation. Results showed considerable increase in activity of the coupled semiconductors with respect to monocomponent one. In NiO-PbO-NCP system, conduction band (CB) of NiO is enough negative for easily migration of photogenerated electrons to CB-PbO level, while such phenomena take place from more negative CB-PbS level to CB-NiS level in NiS-PbS-NCP. These phenomena significantly prevented from electron-hole recombination which increased photocatalytic activity of the coupled semiconductors. Best photodegradation activities obtained by NiO 1.3% –PbO 14.7% -NCP and NiS 2.1% –PbS 10.0% -NCP, confirming semiconductors' mass-ratio dependence of the photocatalytic process. The supported coupled semiconductors showed blue shifts in band gap energies with respect to the bulk semiconductors which confirm formation of semiconductors nanoparticles inside the zeolite framework. The highest degradation percentage of 4-NP was obtained at: 0.5 g L −1 photocatalysts, 15 mg L −1 4-NP at pH 7.5.

  20. Catalytic Pyrolysis of Chilean Oak: Influence of Brønsted Acid Sites of Chilean Natural Zeolite

    Directory of Open Access Journals (Sweden)

    Serguei Alejandro Martín

    2017-11-01

    Full Text Available This paper proposes the Chilean natural zeolite as catalyst on bio-oil upgrade processes. The aim of this study was to analyze chemical composition of bio-oil samples obtained from catalytic pyrolysis of Chilean native oak in order to increase bio-oil stability during storage. In order to identify chemical compounds before and after storage, biomass pyrolysis was carried out in a fixed bed reactor at 623 K and bio-oil samples were characterized by gas chromatography/mass spectrophotometry (GC/MS. A bio-oil fractionation method was successfully applied here. Results indicate that bio-oil viscosity decreases due to active sites on the zeolite framework. Active acids sites were associated with an increment of alcohols, aldehydes, and hydrocarbon content during storage. Higher composition on aldehydes and alcohols after storage could be attributed to the occurrence of carbonyl reduction reactions that promotes them. These reactions are influenced by zeolite surface characteristics and could be achieved via the direct contribution of Brønsted acid sites to Chilean natural zeolite.

  1. Removal of ammonia nitrogen from leachate of Muribeca municipal solid waste landfill, Pernambuco, Brazil, using natural zeolite as part of a biochemical system.

    Science.gov (United States)

    Lins, Cecilia Maria M S; Alves, Maria Cristina M; Campos, Juacyara C; Silva, Fabrícia Maria S; Jucá, José Fernando T; Lins, Eduardo Antonio M

    2015-01-01

    The inadequate disposal of leachate is one of the key factors in the environmental impact of urban solid waste landfills in Brazil. Among the compounds present in the leachates from Brazilian landfills, ammonia nitrogen is notable for its high concentrations. The purpose of this study was to assess the efficiency of a permeable reactive barrier filled with a natural zeolite, which is part of a biochemical system for the tertiary treatment of the leachate from Muribeca Municipal Solid Waste Landfill in Pernambuco, Brazil, to reduce its ammonia nitrogen concentration. This investigation initially consisted of kinetic studies and batch equilibrium tests on the natural zeolite to construct the sorption isotherms, which showed a high sorption capacity, with an average of 12.4 mg NH4+.L(-1), a value close to the sorption rates found for the aqueous ammonium chloride solution. A permeable reactive barrier consisting of natural zeolite, as simulated by the column test, was efficient in removing the ammonia nitrogen present in the leachate pretreated with calcium hydroxide. Nevertheless, the regenerated zeolite did not satisfactorily maintain the sorption properties of the natural zeolite, and an analysis of their cation-exchange properties showed a reduced capacity of 54 meq per 100 g for the regenerated zeolite compared to 150 meq per 100 g for the natural zeolite.

  2. REMOCIÓN DE MICROORGANISMOS PATÓGENOS PRESENTES EN UN LICOR MIXTO BAJO CONDICIONES DE LABORATORIO EMPLEANDO FILTROS EMPACADOS EN ZEOLITA NATURAL REMOVAL OF PATHOGENIC MICROORGANISMS PRESENT IN MIXED LIQUOUR UNDER LABORATORY CONDITIONS BY USING FILTERS PACKED IN NATURAL ZEOLITE

    Directory of Open Access Journals (Sweden)

    Diana Rocío Acevedo Cifuentes

    2012-12-01

    Full Text Available En este artículo, se presentan los resultados obtenidos en la remoción de coliformes totales, coliformes fecales y salmonella-shigella, presentes en un licor mixto proveniente de la planta de tratamiento de aguas residuales San Fernando (Medellín, Colombia, mediante el uso de una batería de filtros empacados en zeolita clinoptilolita. La experimentación se desarrolló bajo condiciones controladas de caudal y pH, a temperatura ambiente. Se empleó zeolita natural tipo clinoptilolita la cual se activó con solución salina y secado, se empacó en una batería compuesta por dos filtros, uno de flujo descendente y otro de flujo ascendente, para facilitar el contacto de la solución contaminada y el material adsorbente (zeolita. Se realizaron cinco ensayos independientes y al final de cada uno de ellos se lavó y se activó el material zeolítico antes de comenzar el siguiente. En cada ensayo se tomaron tres muestras. Se encontró que la eficiencia de los filtros bajo las condiciones específicas de diseño fue significativamente alta en la remoción de los patógenos evaluados, y el porcentaje de remoción fue independiente del valor de la concentración a la entrada del filtro. Además, la eficiencia en la remoción de los patógenos evaluados no dependió del tipo de microorganismo.This article displays results obtained when total coliforms, fecal coliforms, and Salmonella shigella were removed from mixed liquor taken from San Fernando waste water treatment plant in Medellín, Colombia, by using a battery of filters packed in zeolite clinoptilolite. Experiments were developed under controlled conditions of flow and pH at room temperature. Natural clinoptilolite-type zeolite was used activated with saline solution and drying; it was packed in a battery consisting of two filters (a downward-flow filter and an upward-flow filter in order to make contact of contaminated solution and adsorbent material (zeolite easier. Five independent tests were

  3. The effect of clinoptilolite on 137 Cs binding in broiler chickens

    Directory of Open Access Journals (Sweden)

    G. VITOROVIC

    2008-12-01

    Full Text Available The objective of this study was to evaluate the 137 Cs binding capacity of clinoptilolite.In the first in vitro experiment we investigated sorption of 137 Cs to natural and modified forms of clinoptilolite in highly acid solution,prepared to be similar to that of the gut of pigs (pH =2 3at 37 ºC.In the second in vivo experiment 137 Cs binding to a modified form of clinoptilolite was studied in orally contaminated broiler chickens.137 Cs sorption in the high acidity solution depended on clinoptilolite concentration and varied between 30 85 %of the initial activity.In the chickens,three hours after 137 Cs administration,there was 67%and 63%lower accumulation of 137 Cs in meat and edible organs (respectivelyand seven hours after 137 Cs administration,there was 69% and 49% lower accumulation of 137 Cs in meat and edible organs (respectivelycompared to the controls with no clinoptilolite added in food. Natural and modified forms of clinoptilolite have been shown to high sorption efficiency towards 137 Cs ions and could be recommended as possible radiocaesium binders in domestic animals.;

  4. Removal of Pb(II) from water by natural zeolitic tuff: kinetics and thermodynamics.

    Science.gov (United States)

    Karatas, Mustafa

    2012-01-15

    The present study was aimed at examining the ability of a natural zeolitic volcanic tuff to remove Pb(II) ions from aqueous solutions under various conditions. The effects of various parameters such as optimum adsorbent mass, contact time, pH of the medium, Pb(II) concentration, and temperature were investigated. In addition, different adsorption isotherms were obtained using concentrations of Pb(II) ions ranging from 1mg/L to 200mg/L. The adsorption process follows second-order reaction kinetics and follows the Langmuir adsorption isotherm. The thermodynamic parameters are discussed in this article, including changes in Gibbs free energy, entropy, and enthalpy, for the adsorption of Pb(II) on tuff, and it is revealed that the adsorption process was spontaneous and exothermic under natural conditions. The maximum removal efficiency of 92% was obtained at a pH of 5 with a 25-min contact time for a 10 g/L solid-to-liquid ratio and an initial heavy metal concentration of 100mg/L. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Modified natural zeolite as heterogeneous Fenton catalyst in treatment of recalcitrants in industrial effluent

    Directory of Open Access Journals (Sweden)

    Milton M. Arimi

    2017-04-01

    Full Text Available Industrial effluents with high recalcitrants should undergo post-treatment after biological treatment. The aim of this study was to use cheap and abundantly available natural materials to develop heterogeneous Fenton catalysts for the removal of colored recalcitrants in molasses distillery wastewater (MDW. The pellets of zeolite, which is naturally available in many countries, were modified by pre-treatment with sulphuric acid, nitric acid and hydrochloric acid, before embedding on them the ferrous ions. The effects of pH and temperature on heterogeneous Fenton were studied using the modified catalysts. The sulphuric acid-ferrous modified catalysts showed the highest affectivity which achieved 90% color and 60% TOC (total organic carbon removal at 150 g/L pellet catalyst dosage, 2 g/L H2O2 and 25 °C. The heterogeneous Fenton with the same catalyst caused improvement in the biodegradability of anaerobic effluent from 0.07 to 0.55. The catalyst was also applied to pre-treat the raw MDW and increased it's biodegradability by 4%. The color of the resultant anaerobic effluent was also reduced. The kinetics of total TOC removal was found to depend on operation temperature. It was best described by simultaneous first and second order kinetics model for the initial reaction and second order model for the rest of the reaction.

  6. Silver-modified clinoptilolite for the removal of Escherichia coli and heavy metals from aqueous solutions.

    Science.gov (United States)

    Akhigbe, Lulu; Ouki, Sabeha; Saroj, Devendra; Lim, Xiang Min

    2014-09-01

    This paper investigates the potential of using the silver antibacterial properties combined with the metal ion exchange characteristics of silver-modified clinoptilolite to produce a treatment system capable of removing both contaminants from aqueous streams. The results have shown that silver-modified clinoptilolite is capable of completely eliminating Escherichia coli after 30-min contact time demonstrating its effectiveness as a disinfectant. Systems containing both E. coli and metals exhibited 100 % E. coli reduction after 15-min contact time and maximum metal adsorption removal efficiencies of 97, 98, and 99 % for Pb(2+), Cd(2+), and Zn(2+) respectively after 60 min; 0.182-0.266 mg/g of metal ions were adsorbed by the zeolites in the single- and mixed-metal-containing solutions. Nonmodified clinoptilolite showed no antibacterial properties. This study demonstrated that silver-modified clinoptilolite exhibited high disinfection and heavy metal removal efficiencies and consequently could provide an effective combined treatment system for the removal of E. coli and metals from contaminated water streams.

  7. CYCLISATION-ACETYLATION KINETIC OF (R-(+-CITRONELLAL BY Zn2+–NATURAL ZEOLITE AS SOLID SOLVENT CATALYST

    Directory of Open Access Journals (Sweden)

    Edy Cahyono

    2010-07-01

    Full Text Available Kinetic in cyclisation-acetylation of (R-(+-citronellal with acetic anhydride was investigated over Zn2+-Natural zeolite (Zn2+-Natzeo as a catalyst. (R-(+-citronellal has been isolated from citronella oil by fractional distillation under reducing pressure. Enantioselective capillary GC on a Supelco β-DEX 225 column has been used for analysis the enantiomers ratio of citronellal. Catalyst Zn2+-Natzeo has prepared through acid activation of natural zeolite from Malang using HF 1% and HCl 6 M, followed by ion-exchange with 3 M NH4Cl and calcination at 450 °C for 1 h under nitrogen to obtained H-natural zeolite (H-Natzeo. H-Natzeo was modified to Zn2+-Natzeo by ion exchange with 0.1 M ZnCl2. Cyclisation-acetylation reaction was carried out by heating (R-(+-citronellal (CIT, acetic anhydride (AA, and 1 g catalyst in glass batch reactor with vigorous stirring at 80 °C. Molar ratio CIT/AA that used, i.e. 0.25; 0.5; 1.0; 1.2 and 1.5. As the reaction proceeded, 1 mL sample was taken off at 10; 20; 30; 60; 120; 180 min and extracted using n-hexane for every molar ratio. Structure analysis of product was conducted by GC-MS. Kinetic of the cyclisation-acetylation reaction was analyzed according to the Langmuir-Hinshelwood mechanism. Increasing molar ratio of CIT/AA will decrease the isopulegyl acetate (IPA and neo-isopulegyl acetate (NIPA formation. Rate constant of cyclisation-acetylation reaction catalyzed by Zn2+-Natzeo was 30.964-47.619 mmol(min. g cat-1 at 80 °C, 30 min and the ratio  adsorption equilibrium constant KCIT/KAA was 7.09.   Keywords: Cyclisation-acetylation, (R-(+-citronellal, Zn2+-natural zeolite, kinetic

  8. Impacts of addition of natural zeolite or a nitrification inhibitor on antibiotic resistance genes during sludge composting.

    Science.gov (United States)

    Zhang, Junya; Chen, Meixue; Sui, Qianwen; Tong, Juan; Jiang, Chao; Lu, Xueting; Zhang, Yuxiu; Wei, Yuansong

    2016-03-15

    Composting is commonly used for the treatment and resource utilization of sewage sludge, and natural zeolite and nitrification inhibitors can be used for nitrogen conservation during sludge composting, while their impacts on ARGs control are still unclear. Therefore, three lab-scale composting reactors, A (the control), B (natural zeolite addition) and C (nitrification inhibitor addition of 3,4-dimethylpyrazole phosphate, DMPP), were established. The impacts of natural zeolite and DMPP on the levels of ARGs were investigated, as were the roles that heavy metals, mobile genetic elements (MGEs) and the bacterial community play in ARGs evolution. The results showed that total ARGs copies were enriched 2.04 and 1.95 times in reactors A and C, respectively, but were reduced by 1.5% in reactor B due to the reduction of conjugation and co-selection of heavy metals caused by natural zeolite. Although some ARGs (blaCTX-M, blaTEM, ermB, ereA and tetW) were reduced by 0.3-2 logs, others (ermF, sulI, sulII, tetG, tetX, mefA and aac(6')-Ib-cr) increased by 0.3-1.3 logs after sludge composting. Although the contributors for the ARGs profiles in different stages were quite different, the results of a partial redundancy analysis, Mantel test and Procrustes analysis showed that the bacterial community was the main contributor to the changes in ARGs compared to MGEs and heavy metals. Network analysis determined the potential host bacteria for various ARGs and further confirmed our results. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Dyes adsorption blue vegetable and blue watercolor by natural zeolites modified with surfactants

    International Nuclear Information System (INIS)

    Jardon S, C. C.; Olguin G, M. T.; Diaz N, M. C.

    2009-01-01

    In this work was carried out the dyes removal blue vegetable and blue watercolor of aqueous solutions, to 20 C, at different times and using a zeolite mineral of Parral (Chihuahua, Mexico) modified with hexadecyl trimethyl ammonium bromide or dodecyl trimethyl ammonium bromide. The zeolite was characterized before and after of its adaptation with NaCl and later with HDTMABr and DTMABr. For the materials characterization were used the scanning electron microscopy of high vacuum; elementary microanalysis by X-ray spectroscopy of dispersed energy and X-ray diffraction techniques. It was found that the surfactant type absorbed in the zeolite material influences on the adsorption process of the blue dye. Likewise, the chemical structure between the vegetable blue dye and the blue watercolor, determines the efficiency of the color removal of the water, by the zeolites modified with the surfactants. (Author)

  10. UO{sub 2}{sup 2+} sorption in natural Mexican erionite and Y zeolite

    Energy Technology Data Exchange (ETDEWEB)

    Olguin, M.T.; Solache, M. [Instituto Nacional de Investigaciones Nucleares (Mexico); Asomoza, M. [Universidad Autonoma Metropolitana, Iztapalapa (Mexico)] [and others

    1994-10-01

    The use of Y zeolite and erionite to remove UO{sub 2}{sup 2+} ions from aqueous solutions has been investigated. The effect of temperature, the concentration of UO{sub 2}{sup 2+} uptake, the diffusion coefficients, and the ion-exchange isotherms were also studied. The diffusion coefficients are not clearly affected by temperature or concentration. They definitely depend on the structure of each zeolite. The UO{sub 2}{sup 2+} exchange capacities were 0.2037 and 0.7345 meq UO{sup 2}{sup 2+}/g for erionite and Y zeolite, respectively. It was found that UO{sub 2}{sup 2+} is exchanged with the cations of the large cavity in Y zeolite. In the case of erionite, UO{sub 2}{sup 2+} is exchanged with the cations localized in sites where the charge densities are very high.

  11. The nature of cationic adsorption sites in alkaline zeolites-single, dual and multiple cation sites

    Czech Academy of Sciences Publication Activity Database

    Nachtigall, P.; Delgado, M. R.; Nachtigallová, Dana; Arean, C. O.

    2012-01-01

    Roč. 14, č. 5 (2012), s. 1552-1569 ISSN 1463-9076 R&D Projects: GA ČR GA203/09/0143 Institutional research plan: CEZ:AV0Z40550506 Keywords : exchanged ZSM-5 zeolites * carbon-monoxide adsorption * low-temperature CO * solid-state NMR * high-silica zeolites Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.829, year: 2012

  12. Electron microscopy studies of natural and synthetic zeolites impregnated with uranyl dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Acosta, Dwight R.; T-Olguin, Maria; Solache, Marcos; Bosch, Pedro; Bulbulian, Silvia [Universidad Nacional Autonoma de Mexico, Mexico City (Mexico). Inst. de Fisica; Asomoza, Max [Instituto Nacional de Investigaciones Nucleares, Mexico City (Mexico). Dept. de Quimica Nuclear

    1995-09-01

    Full text. The use of Y zeolite and erionite to remove uranyl dioxide ions from aqueous solution is focussed on catalysis and energy transfer problems but it can be oriented to recovery uranyl dioxide ions, among other radioactive compounds. The samples impregnated with uranyl dioxide at several concentrations and contact times were studied using conventional, high resolution and scanning electron microscopy in order to detect changes as consequence of contact with a radioactive material and to verify mechanical stability of zeolites. Also X ray diffraction, thermal analysis, neutron activation were used to characterize the samples at several steps of treatment. The crystallinity of zeolites was maintained only when using dilute uranyl nitrate solution (up to 0.0100 N for y zeolite and 0.0300 N for erionite). The samples impregnated with highest nitrate concentrations partially lost their crystallinity. From selected area electron diffraction pattern, lattice parameter variations were detected and from high resolution electron microscopy localization of uranyl ions in and on zeolite structure was determined. Surface modification in zeolites was observed by scanning electron microscopy just for samples with long contact time with radioactive solutions. (author)

  13. Bacterial inactivation in water by means of a combined process of pulsed dielectric barrier discharge and silver-modified natural zeolite

    International Nuclear Information System (INIS)

    Rodríguez-Méndez, B G; López-Callejas, R; Olguín, M T; Valencia-Alvarado, R; Peña-Eguiluz, R; Mercado-Cabrera, A; Alcántara-Díaz, D; Muñoz-Castro, A E; Hernández-Arias, A N; De la Piedad-Beneitez, A

    2014-01-01

    We propose a novel combined system of pulsed dielectric barrier discharges (PDBDs) and silver-modified natural zeolite (Ag–zeolite) in liquid in bubbles. The system was tested with the Escherichia coli bacteria immersed in water. In order to evaluate the efficiency of the system in bacterial inactivation a microbiological analysis was carried out; 9.82-ln of bacterial reduction was obtained using the combined system, whereas 0.43-ln of bacterial reduction was obtained using Ag–zeolite alone, and 6.26-ln with PDBD. The elapsed time was 10 minutes for the three treatments. (paper)

  14. Combined used of natural zeolites and microalgaes for the denitrification of wastewater from fertilizer plants; Uso combinado de zeolitas naturales y microalgas en la denitrificacion de aguas residuales

    Energy Technology Data Exchange (ETDEWEB)

    Soca Olazabal, N.; Blanco Toledo, F.; Pizarro Camacho, D.

    1997-06-01

    In our work we investigated the process of denitrification of waster-water with high percentage of nitrate and ammonia using natural zeolites that can be used later in agricultures fertilizer, because of the nitrogen load received. This effluents was used for micro algae growth reducing the nitrate concentration, the micro algae was Chlorella Vulgaris. The zeolite reduced the NH``+{sub 4} concentration up to 5 mg/l. and the NH``+{sub 4} concentration in the zeolite, it si very important in the agriculture. The chlorella Vulgaris reduces 30 mg/l of nitrate in six hours in the steady state. (Author) 9 refs.

  15. Immobilization of Co2+ and Cs+ in zeolites by thermal treatment and by combustion

    International Nuclear Information System (INIS)

    Rodriguez T, R.; Bulbulian G, S.

    2005-01-01

    The radioactive waste, either those that take place in the 235 U fission or those that are used in the radiochemical laboratories, are dangerous for the human being and for the one environment. The liquid radioactive wastes are of those that present bigger problem. It has intended to retain by the ion exchange method the radioactive ions of the liquids using, for example, zeolites. In this work so much synthetic zeolites was used (A and X) like a natural zeolite (clinoptilolite). Its were put in contact with cobalt or cesium solutions to simulate radioactive solutions. A part of the zeolite cations were exchanged with cobalt or cesium cations, eliminating them by this way of the solution. However, in extreme conditions these cations can be leached of the solids. To immobilize the cobalt or cesium cations in the zeolites net its are usually carried out thermal treatments to such temperatures that the structure is destroyed and that the contaminating ions are trapped in a solid often vitreous. The exchanged zeolites with cobalt or cesium, on one hand, its were thermally treated to different temperatures during three hours and by the other one, according to the treatment method by combustion, to different temperatures during five minutes in presence of urea, later its were put in contact with a solution of NaCl to measure the leaching of the interest cations. These solutions were analyzed by neutron activation. In general it was found that as the treatment temperature increases (in both methods) the so much immobility of the cesium like of the cobalt it increases. The grade of crystallinity of the samples before and after the treatments it was determined by X-ray diffraction. (Author)

  16. Comparative resilience of soil and natural zeolite against adverse features of a municipal sewage. A preliminary investigation

    International Nuclear Information System (INIS)

    Buondonno, A.; Coppola, E.; Capra, G.F.; De Riso, S.; Duras, M.G.; Selis, G.; Vacca, S.; Colella, C.

    2008-01-01

    A research was started aiming at evaluating the possible use of natural zeolites as exchange conditioners to improve and make durable the soil resilience against the adverse effects of the use of anomalous waters for irrigation purposes. This paper deals with a preliminary investigation on the comparative resilience of an Entisol with poor exchange properties and of a Neapolitan yellow tuff (NYT) sample against the adverse features of a dirty municipal sewage (DSW). Results showed that NYT treatment largely and significantly improved the poor soil exchange activity. In particular. NYT exchange sites selectively took up ammonium from DSW. As a consequence, ammonium was trapped, then protected against losses in the environment and, concurrently, exchangeable cations, such as K and Ca, were made free as plant nutrients. The results highlight the possible positive role of zeolitized tuff in restoring and sustaining soil resilience.

  17. Application of 119Sn CPMG MAS NMR for Fast Characterization of Sn Sites in Zeolites with Natural 119Sn Isotope Abundance

    DEFF Research Database (Denmark)

    G. Kolyagin, Yury; V. Yakimo, Alexander; Tolborg, Søren

    2016-01-01

    119Sn CPMG MAS NMR is demonstrated to be a fast and efficient method for characterization of Sn-sites in Sn-containing zeolites. Tuning of the CPMG echo-train sequence decreases the experimental time by a factor of 5–40 in the case of as-synthesized and hydrated Sn-BEA samples and by 3 orders......-BEA zeolites with natural 119Sn isotope abundance using conventional MAS NMR equipment....

  18. Natural zeolites filling amygdales and veins in basalts from the British Tertiary Igneous Province on the Isle of Skye, Scotland

    Directory of Open Access Journals (Sweden)

    Triana J M

    2012-10-01

    Full Text Available

    ABSTRACT

    Natural zeolites filling amygdales and veins in tertiary basaltic host rocks on the Isle of Skye (NW Scotland have been studied in some detail by transmitted light microscopy, scanning electron microscopy and X-ray diffraction techniques . The zeolites and associated minerals so identified in order of their relative time of formation from early to late were nontronite, amorphous silica phases, carbonate phases, chabazite, phillipsite, wairakite, thomsonite, analcime, natrolite and stilbite-type minerals . Zeolite formation in the Skye basalts began with low Si/Al ratio Na zeolites and a gradual increase in Ca content and Si/Al ratio, ending up as Ca zeolites . They were probably formed as a consequence of late-stage hydrothermal activity, although, locally, contact metamorphism may control the process of zeolite formation

    RESUMEN

    Las zeolitas naturales como relleno en amígdalas y venas que ocurren en rocas basálticas Terciarias de la Isla de Skye (NW Escocia han sido estudiadas en detalle por técnicas de microscopía de luz transmitida, microscopía electrónica de barrido y difracción de rayos X. Las zeolitas y los minerales asociados identificados, en orden de su tiempo relativo de formación, son nontronita, fases de sílice amorfa, carbonatos, chabazita, filipsita, wairakita, thomsonita, analcima, natrolita y minerales tipo estilbita. La formación de zeolitas en los basaltos de Skye comenzó con una zeolita rica en Na de baja relación Si/Al y con el aumento gradual en el contenido de Ca y Si/Al, terminó con una zeolita rica en Ca Estas probablemente se formaron como consecuencia de una actividad hidrotermal tardía, aunque localmente un metamorfismo de contacto pudo controlar el proceso de formación de las zeolitas

  19. Plasma-assisted reduction of silver ions impregnated into a natural zeolite framework

    Science.gov (United States)

    Osonio, Airah P.; Vasquez, Magdaleno R.

    2018-02-01

    A green, dry, and energy-efficient method for the fabrication of silver-zeolite (AgZ) composite via 13.56 MHz radio-frequency plasma reduction is demonstrated. Impregnation by soaking and ion-exchange deposition were performed to load the silver ions (Ag+) into the sodium-zeolite samples. Characterization was performed by optical emission spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and Brunauer-Emmett-Teller analyses. Results indicate the successful reduction of Ag+ to its metallic state on the surface of the zeolite with a mean diameter of 165 nm. This plasma-induced reduction technique opens possibilities in several areas including catalysis, adsorption, water treatment, and medicine.

  20. RESEARCH OF MICROWAVE DRYING OF NATURAL ZEOLITE GRANULES AND ITS INFLUENCE ON THE TECHNOLOGICAL PROPERTIES

    Directory of Open Access Journals (Sweden)

    Rybachuk V.D.

    2016-06-01

    Full Text Available Introduction. The wet granulation technique is often used in the preparation of free-flowing granules in the manufacture of tablets and capsules. It is very important that granules obtained by this technology be dried before further processing. And also, it is important that the method of drying is entirely controlled and managed and the result is quite predictable. In recent years, microwave drying of granules make a considerable interest. Microwave drying is especially useful for moisture sensitive materials which are mostly pharmaceutical substances. Microwave drying technology is useful for dosage forms with high purity, since this method provides the possibility of drying in the same container production, which reduces the chance of cross contamination of matter and its direct contact with staff. The aim of this work was to study the effect of microwave radiation on the technological properties of natural zeolite peets compared to traditional convection method and to determine the optimal drying modes and specific humidity of the material. Material & methods. Granules were prepared by wet granulation technology by using a laboratory granulator NG-12. As the humidifier we used potato starch gel and PVP in an amount of 25% by weight of the dry product. The resulting granules were divided into two equal parts and subjected to drying in a microwave oven (Delfa D20MW of installed capacity (119 W, 280 W, 336 W, 462 W, ​​595 W and 700 W and shelf dryer to a residual moisture level of 0.01 g.w./g.d.m. or less. Determination of the specific humidity of granules was carried out by mass loss on drying. Fractional composition of granules was determined using a standard set of sieves with the diameter of the holes 2.0; 1.0; 0.5 and 0.25 mm. The friability of the granules was determined using friabilator Pharma Test PTF 10E / ER, Germany. To characterize the fluidity of granule Carr`s indicator (IC and coefficient Hausnera (HR. Results & discussion

  1. Adsorbent from Waste and Natural Deposits for Paraquat Removal in Water

    International Nuclear Information System (INIS)

    Nur Fatin Zakaria; Zaiton Abdul Majid; Zainab Ramli

    2016-01-01

    Studies on the removal of frequently used herbicide for controlling broad-leafed weeds, Paraquat Dichloride (PQ) has been carried out intensively. Waste from steelmaking industries (Electric Arc Furnace (EAF) slag) and natural zeolite (clinoptilolite) were used as the starting materials. Preparation of an adsorbent involved two steps, namely extraction iron oxide (IO) from slag and precipitation of IO onto clinoptilolite. Characterization of NZIC were done using Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), single-point Brunauer Emmett Teller (BET) surface area analysis, Vibrating Sample Magnetometer (VSM) and pH at zero point charge (pHzpc). The NZIC showed a lower magnetic saturation at 8.13 emu/ g compared to maghemite at 29.5 emu/ g. The BET surface area of NZIC was 146.29 m 2 / g, larger compared to the individual surface area of clinoptilolite and maghemite which are 37.84 and 17.84 m 2 / g respectively. Adsorption of PQ onto clinoptilolite and NZIC were investigated using a batch experiment. Surface characteristic of NZIC was investigated by pHzpc experiment showing that at pH 8.2 its electric surface charge is zero. Optimum parameters for adsorption of PQ in water were found at pH 12 with 0.01 g/ 10 mL of NZIC and equilibrium time of 20 minutes. Desorption experiment revealed that NZIC have a good recovery in repetitive usage for PQ removal in water. (author)

  2. Insecticidal potential of natural zeolite and diatomaceous earth formulations against rice weevil (Coleoptera: Curculionidae) and red flour beetle (Coleoptera: Tenebrionidae).

    Science.gov (United States)

    Andrić, Goran G; Marković, Mirjana M; Adamović, Milan; Daković, Aleksandra; Golić, Marijana Prazić; Kljajić, Petar J

    2012-04-01

    Insecticidal potential of natural zeolites and diatomaceous earths originating from Serbia against Sitophilus oryzae (L.) and Tribolium castaneum (Herbst) was evaluated. Two natural zeolite formulations (NZ and NZ Modified) were applied to wheat at rates of 0.50, 0.75, and 1.0 g/kg, while two diatomaceous earth (DE) formulations (DE S-1 and DE S-2) were applied at rates of 0.25, 0.50, 0.75, and 1.0 g/kg. A bioassay was conducted under laboratory conditions: temperature of 24 +/- 1 degrees C, relative humidity in the range 50-55%, in tests with natural zeolites, and 60-65%, in tests with DEs, and in all combinations for progeny production. Mortality was assessed after 7, 14, and 21 d of insect contact with treated wheat, and the total mortality after an additional 7-d recovery on untreated broken wheat. Progeny production was also assessed after 8 wk for S. oryzae and 12 wk for T. castaneum. The highest mortality for S. oryzae and T. castaneum was found after the longest exposure period and 7 d of recovery, on wheat treated with NZ at the highest rate and DEs at rates of 0.50 -1.0 g/kg. Progeny reduction higher than 90% was achieved after 14 and 21 d of contact of both beetle pests with wheat treated with DE S-1 at 0.50-1.0 g/kg and DE S-2 at 0.75-1.0 g/kg, while the same level of reduction was achieved only for T. castaneum after its contact with the highest rate of NZ formulation. NZ Modified, applied even at the highest rate, revealed much lower insecticidal potential.

  3. Characteristics Buton Natural Asphalt-Rubber (BNA-R) on the Performance Improvement of Warm Mix Asphalt Using Natural Zeolite

    Science.gov (United States)

    Wahjuningsih, Nurul; Pranowo Hadiwardoyo, Sigit; Jachrizal Sumabrata, R.

    2018-03-01

    The decrease in the ability of service of pavement can be caused by the durability factor in the pavement layer in receiving heavy traffic load and the temperature of the pavement. Permanent deformation is one of the criteria of failure of asphalt mixture. Performance assessment of the asphalt mixture can be observed from the rheological properties of asphalt binder. The use of BNA-R in this study is intended to modify the characteristics of bitumen penetration grade 60 / 70 used in warm mix asphalt. Warm mix asphalt with lower temperatures of mixing and compaction than conventional asphalt mixtures was chosen because it is more environmentally friendly. To reduce the temperature in this warm asphalt technology is achieved by using natural zeolite. Both of these materials are local materials that are widely available in Indonesia. The rheology of asphalt 60/70 modified with BNA-R indicates that the addition of BNA-R in the base asphalt increase the complex modulus value and decrease the phase angle value. These values were related to the performance of mixture in the permanent deformation criteria. Reducing the temperature of mixing and compaction should be balanced with modifying the asphalt binder used. Rutting due to permanent deformation can resulted in inconvenience to the passengers and can lead to high costs of road maintenance. To determine the permanent deformation of asphalt mix with material combinations was performed through the wheel tracking test machine with 3,780 cycles for 3 hours. The results shows that after test track over 7 thousand passes have seen permanent deformation characteristics of asphalt concrete mixture with a variation of the characteristics of bitumen.

  4. Purification of Effluent from the Groundwood Production by Organo-zeolite

    Directory of Open Access Journals (Sweden)

    Anić-Vučinić, A.

    2008-11-01

    Fig. 1B the pertaining zeta potentials of the samples are shown. HDTMA cations were essentially quantitatively taken up by the clinoptilolite tuff up to loading level of L = 0.204 mmol g-1-(Fig. 1A. The results of the zeta potential measurements show that the negative surface charge changed to positive after modification with surfactant solutions (Fig. 1B. HDTMA cations form a stable organophilic coating on the clinoptilolite surface, and above surfactant loading level of 0.110 mmol g-1(isoelectric point, a second layer of HDTMA+ cations reverses the surface charge into positive. The optimal mass concentration of coagulant AlCl3·6H2O for the tested wastewater is γ = 0.8 g dm-1(Figs. 2A and 2B. Zeta potential of the solution above sediment received by coagulation with AlCl3·6H2O of mass concentration γ= 0.8 g dm-3 is ζ= -3.92 mV. The efficiency of removing the turbidity (Table 1 and COD is η = 67 % (from 799 to 263 NTU and 54% (from 13 200 to 6 040 mg dm-3. The efficiency of removing solved organic carbon and colour is significantlylesser: 22.7% (from 3010 to 2322 mg dm-3 and η = 33.0 % (from 681 to 457 Pt Co. By processing the solutions received after coagulation with AlCl3·6H2O of mass concentration of 0.8 g dm-3, with natural tuff and organo-zeolites whose loading are: 0.074; 0.123; 0.164 and 0.204 mmol g-1 HDTMA, TOC was decreased from γ=2322 mg dm-3 to the following: γ=2042, 1976, 1945, 1907 and 1821 mg dm-3 and was sorbed: q = 28.0; 34.6; 37.7; 41.5; and 50.1 mg g-1 TOC (Fig. 3A. Using the sample of organo-zeolite with loading of 0.204 mmol g-1 HDTMA, the efficiency of removing the organic carbon was improved from η= 22.7 % to 40.0 %. The efficiency of discolouring the tested solutions also increases with the change of the surface charge of organo-zeolites from negative to positive(Fig. 3B. The efficiency of removing the colour by using the natural tuff was improved from η= 33.0 % to η = 40.0 %, and by using the organo-zeolite with loading of L = 0

  5. Design and characterization of chitosan/zeolite composite films — Effect of zeolite type and zeolite dose on the film properties

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Gustavo P.; Debone, Henrique S. [Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Universidade Federal de São Paulo, Diadema (Brazil); Severino, Patrícia [Universidade Tiradentes, Instituto de Tecnologia e Pesquisa, Aracaju (Brazil); Souto, Eliana B. [Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Coimbra (FFUC), Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548, Coimbra (Portugal); Center for Neuroscience and Cell Biology & Institute for Biomedical Imaging and Life Sciences (CNC-IBILI), University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548, Coimbra (Portugal); Silva, Classius F. da, E-mail: cfsilva@unifesp.br [Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Universidade Federal de São Paulo, Diadema (Brazil)

    2016-03-01

    Chitosan films can be used as wound dressings for the treatment of chronic wounds and severe burns. The antimicrobial properties of these films may be enhanced by the addition of silver. Despite the antimicrobial activity of silver, several studies have reported the cytotoxicity as a factor limiting its biomedical applications. This problem may, however, be circumvented by the provision of sustained release of silver. Silver zeolites can be used as drug delivery platforms to extend the release of silver. The objective of this study was to evaluate the addition of clinoptilolite and A-type zeolites in chitosan films. Sodium zeolites were initially subjected to ion-exchange in a batch reactor. Films were prepared by casting technique using a 2% w/w chitosan solution and two zeolite doses (0.1 or 0.2% w/w). Films were characterized by thermal analysis, color analysis, scanning electron microscopy, X-ray diffraction, and water vapor permeation. The results showed that films present potential for application as dressing. The water vapor permeability is one of the main properties in wound dressings, the best results were obtained for A-type zeolite/chitosan films, which presented a brief reduction of this property in relation to zeolite-free chitosan film. On the other hand, the films containing clinoptilolite showed lower water vapor permeation, which may be also explained by the best distribution of the particles into the polymer which also promoted greater thermal resistance. - Highlights: • Zeolite/chitosan composite films were prepared by casting technique. • Micrographs showed slight difference according to the content and A-type zeolite. • The barrier properties of the films were suitable to the dressing application. • Film characterization suggested that zeolites interacted with the chitosan chain.

  6. OPTIMATION OF TIME AND CATALYST/FEED RATIO IN CATALYTIC CRACKING OF WASTE PLASTICS FRACTION TO GASOLINE FRACTION USING Cr/NATURAL ZEOLITE CATALYST

    Directory of Open Access Journals (Sweden)

    Wega Trisunaryanti

    2010-06-01

    Full Text Available Optimation of time and catalyst/feed ratio in catalytic cracking of waste plastics fraction to gasoline fraction using Cr/Natural Zeolite catalyst has been studied.The natural zeolite was calcined by using nitrogen gas at 500 oC for 5 hours. The chromium supported on to the zeolite was prepared by ion exchange methode with Cr(NO33.9H2O solution with chromium/zeolite concentration of 1% (w/w. The zeolite samples were then calcined  with nitrogen gas at 500 oC for 2 hours, oxidyzed with oxygen gas and reduced with hydrogen at 400 oC for 2 hours. The characterization of the zeolite catalyst by means of Si/Al ratio by UV-Vis spectroscopy, acidity with pyridine vapour adsorption and Na, Ca and Cr contents by atomic adsorption spectroscopy (AAS. The catalyst activity test was carried out in the cracking process of waste plastics fraction with boiling point range of 150 - 250 °C (consisted of C12 - C16 hydrocarbons at 450 oC for 30 min, 60 min and 90 min, and catalyst/feed ratio 1/1, 1/2, 1/3, ¼ (w/w. The result of catalyst activity test  showed  that  the maximum number  conversion of gasoline fraction (C5-C11 is 53,27% with relatively low coke formation using 1/3 catalyst/feed ratio and the cracking time of 60 min.. This  catalyst has  Si/Al ratio = 1,21 (w/w , acidity = 0,16 mmol/g and Na content = 0,81%, Ca content = 0,15% and Cr content 0,24%.   Keywords: zeolite, catalytic cracking, gasoline, chromium.

  7. Discerning the Location and Nature of Coke Deposition from Surface to Bulk of Spent Zeolite Catalysts

    OpenAIRE

    Devaraj, Arun; Vijayakumar, Murugesan; Bao, Jie; Guo, Mond F.; Derewinski, Miroslaw A.; Xu, Zhijie; Gray, Michel J.; Prodinger, Sebastian; Ramasamy, Karthikeyan K.

    2016-01-01

    The formation of carbonaceous deposits (coke) in zeolite pores during catalysis leads to temporary deactivation of catalyst, necessitating regeneration steps, affecting throughput, and resulting in partial permanent loss of catalytic efficiency. Yet, even to date, the coke molecule distribution is quite challenging to study with high spatial resolution from surface to bulk of the catalyst particles at a single particle level. To address this challenge we investigated the coke molecules in HZS...

  8. Selectivity of an Active Natural Zeolite in Catalytic Conversion Process of Bangkirai, Kruing and Kamper Woods Biofuel to Gasoline Fraction

    Directory of Open Access Journals (Sweden)

    Wega Trisunaryanti

    2010-06-01

    Full Text Available The selectivity of an active natural zeolite (ZAAH in catalytic conversion process of Bangkirai, Kruing and Kamper woods biofuels has been studied. The ZAAH catalyst was prepared from a natural zeolite (ZA treated with acids solution (1% HF and 6M HCI and hydrothermal then calcined at 500 °C and oxidized at 400 °C under nitrogen and oxygen gas stream, respectively. Characterizations of the catalysts including Si/Al ratio and acidity were determined by atomic adsorption spectroscopy (AAS and ammonia gas adsorption method, respectively. The conversion process was carried out in a flow reactor system at 400 °C, under N2 stream (20 mL/min. The biofuel was vaporized from the pyrolysis zone to the catalytic reactor. A liquid product was covered and analyzed by gas chromatograph (GC and that connected with mass spectroscopy (GC-MS. The characterization results showed that the Si/AI ratio and acidity of the ZAAH were higher than that of the ZA catalyst. The GC-MS data showed that the highest product selectivity was 2,4-dimethyl heptane and 1,2-dimethyl benzene. The total product selectivity using the ZAAH catalyst (bangkirai = 68.10%; kruing = 54.76%; kamper = 50.72% was higher than that of the ZA catalyst (bangkirai = 39.24%; kruing = 44.38%; kamper = 46.11%.

  9. Preparation and characterization of Ni based on natural zeolite catalyst for citronellol conversion to 3,7-Dimethyl-1-Octanol

    Science.gov (United States)

    Sudiyarmanto, Hidayati, Luthfiana N.; Kristiani, Anis; Ghaisani, Almira; Sukandar, Dede; Adilina, Indri B.; Tursiloadi, Silvester

    2017-11-01

    Citronella oil is a kind of essential oil that contains three main components, namely citronellal, citronellol, and geraniol. The high demand of citronellal and geraniol derivative prompted scientists to develop methods which are stereo-selective synthesis. A hydrogenation reaction using heterogeneous catalyst is one way of synthesis of citronella oil derivatives. In this research, synthesis of citronellol oil derivatives using Ni based on natural zeolite (Ni/ZAB) catalyst which is expected to produce the compound of 3,7-dimethyl-1-octanol. The catalyst was prepared by supporting Ni on natural zeolite by impregnation method. The physical and chemical properties of Ni/ZAB catalyst have been characterized by TGA, BET, XRD and FTIR instrumentations. Variation of pressure and temperature reactions were conducted to determine the optimum conditions for the hydrogenation of citronellol. The products from this reaction were analyzed using GC-MS instrumentation. The yield and selectivity of 3,7-dimethyl-1-octanol compound were achieved with optimum conditions at 200°C and 20 bar during 3 hours which produced around 51.97% and 47.81% respectively.

  10. Anaerobic treatment of palm oil mill effluent in batch reactor with digested biodiesel waste as starter and natural zeolite for microbial immobilization

    Science.gov (United States)

    Setyowati, Paulina Adina Hari; Halim, Lenny; Mellyanawaty, Melly; Sudibyo, Hanifrahmawan; Budhijanto, Wiratni

    2017-05-01

    Palm oil mill effluent (POME) is the wastewater discharged from sludge separation, sterilization, and clarification process of palm oil industries. Each ton of palm oil produces about half ton of high organic load wastewater. Up to now, POME treatment is done in lagoon, leaving major problems in land requirement and greenhouse gasses release. The increasing of palm oil production provokes the urgency of appropriate technology application in treating POME to prevent the greenhouse gasses emission while exploit POME as renewable energy source. The purposes of this study were firstly to test the effectiveness of using the digested biodiesel waste as the inoculum and secondly to evaluate the effectiveness of natural zeolite addition in minimizing the inhibitory effect in digesting POME. It was expected that the oil-degrading bacteria in the inoculum would shorten the adaptation period in digesting POME. Furthermore, the consortium formation of anaerobic bacteria accelerated by natural zeolite powder addition would increase the microbial resistance to the inhibitors contained in the POME. The batch digesters, containing 0 (control); 17; 38; and 63 g natural zeolite/g sCOD substrate were observed for 43 days. The result showed that zeolite addition did not give significant effect on sCOD reduction (97.3-98.6% of initial sCOD). Moreover, addition of immobilization media up to 17 g natural zeolite/g stimulated the acidification and biogas production up to 10% higher than control. The purity of methane produced with various amount of immobilization media did not differ for each variation, i.e. 50-54% v/v methane. The increasing amount of natural zeolite up to 63 g/g sCOD did not significantly enhance biogas product rate nor methane content.

  11. Natural Mexican zeolite, potential material for hydrogen storage; Zeolita natural mexicana, material para su posible uso en el almacenamiento de hidrogeno

    Energy Technology Data Exchange (ETDEWEB)

    Iturbe-Garcia, J. L.; Lopez Munoz, B. E. [Instituto Nacional de Investigaciones Nucleares (Mexico)]. E-mail: joseluis.iturbe@inin.gob.mx

    2009-09-15

    This work presents a study of the use of natural Mexican zeolite as a possible alternative for hydrogen storage. This zeolite material is from the state of Sonora. Its particle size was decreased using a grinding treatment with a mechanical alloying system for 5 hours. The mechanical alloying equipment was built in our Institute (Instituto Nacional de Investigaciones Nucleares, ININ). Later, zeolite in powder form was characterized with x-ray diffraction and sweep electron microscopy. It was heated in a micro-reactor at 350 degrees Celsius, which was simultaneously emptied over 2 hours to eliminate humidity and possible gases trapped in its structure. Next, the temperature was reduce to 10 degrees Celsius and it was placed in contact with ultra-high pure hydrogen at a pressure of 10 bars for 10 minutes. The analysis of hydrogen trapped in the zeolite was conducted with gas chromatography. The results of the chromatograms indicate that the zeolite absorbed and liberated the hydrogen in completely different conditions than those reported in the literature. That is, with our experimental conditions at low pressure and temperature, the hydrogen was absorbed in this type of material. [Spanish] En este trabajo se presenta un estudio sobre el uso de una zeolita natural de origen mexicano como posible alternativa para almacenar hidrogeno. Este material zeolitico procede del Estado de Sonora, al cual se le disminuyo el tamano de particula mediante un tratamiento de molienda con un sistema de aleado mecanico durante 5 horas. El equipo de aleado mecanico se construyo en nuestro Instituto (Instituto Nacional de Investigaciones Nucleares, ININ). Posteriormente, la zeolita en forma de polvo se caracterizo por medio de difraccion de rayos X y microscopia electronica de barrido. Se sometio a calentamiento en un micro-reactor a 350 grados Celsios y al mismo tiempo haciendo vacio durante 2 horas, para eliminar humedad y posibles gases que estuvieran atrapados en su estructura. En

  12. Hydration of portland cement, natural zeolite mortar in water and sulphate solution

    Directory of Open Access Journals (Sweden)

    Janotka, I.

    2003-03-01

    Full Text Available The objective of this paper is to characterise sulphate resistance of mortars made from ordinary Portland cement ( PC and Portland-pozzolan cement with 35 wt.% of zeolite addition (zeolite-blended cement-ZBC . Mortars with two different cement types were tested in water and 5% sodium sulphate solution for 720 days. A favourable effect of zeolite on increased sulphate resistance of the cement is caused by decrease in free Ca(OH2 content of the mortar There is not sufficient of Ca(OH2 available for reacting with the sulphate solution to form voluminous reaction products. A decreased C3A, content due to 35 wt.% replacement of PC by zeolite is the next pronounced factor improving resistance of the mortar with such blended cement.

    El objetivo de este trabajo ha sido estudiar la resistencia a los sulfatos de morteros preparados con cemento portland ordinario (PC y cemento portland puzolánico, con un 35% en peso de zeolita (zeolite-blended cement (ZBC. Ambos tipos de morteros fueron conservados en agua y en una disolución de sulfato sódico al 5% durante 720 días. Se observó una mayor resistencia a los sulfatos en el mortero preparado con el cemento que contenía zeolita debido a su menor contenido en Ca(OH2. No hay cantidad suficiente de Ca(OH2 para que se produzca la reacción de los constituyentes de la pasta con la disolución de sulfato sódico y formar así productos de naturaleza expansiva. La disminución en el contenido de C,3A, debida a la sustitución de un 35% en peso de PC por zeolita, es el factor más determinante en el aumento de la resistencia del mortero en los cementos con adición.

  13. Metal adsorption capabilities of clinoptilolite and selected strains of bacteria from mine water

    Science.gov (United States)

    Mamba, B. B.; Dlamini, N. P.; Nyembe, D. W.; Mulaba-Bafubiandi, A. F.

    Small-scale mining has socio-economic advantages such as the reduction of unemployment and the general improvement of the economy. However, these operations if not properly managed or controlled have a potential to cause environmental damage, particularly with respect to the contamination of groundwater and water supplies that are not distant from where these mining activities take place. This paper focuses on metal removal from water contaminated by heavy metals emanating from small-scale mining operations using clinoptilolite and bacteria. Removal of As, Ni, Mn, Au, Co, Cu and Fe was carried out on mine water samples using original and HCl-activated (in 0.02 M and 0.04 M) natural clinoptilolite and bacterial strains (a mixed consortia of Bacillus strains ( Bacillus subtilis, Bacillus cereus, Bacillus firmus, Bacillus fusiformis, Bacillus macroides and Bacillus licheniformis), Pseudomonas spp., Shewanella spp. and a mixed consortia of Acidithiobcillus caldus, Leptospirillum spp., Ferroplasma spp. and Sulphobacillus spp.). The purpose of the study was to compare the removal efficiencies of the bacterial strains versus natural clinoptilolite adsorbents for metal cations. The Bacillus consortia removed most of the metals up to 98% metal removal efficiency with the exception of nickel where clinoptilolite showed good removal efficiency. The 0.02 M HCl-activated clinoptilolite also demonstrated excellent removal capabilities with Cu, Co and Fe removal efficiency of up to 98%. Both clinoptilolite and bacteria demonstrated capabilities of removing Cu 2+, Co 2+, Fe 2+, Mn 2+, As 3+ and Au from solution which augurs well for metal recovery from mining and mineral processing solutions, as well as in water decontamination.

  14. The use of zeolites to generate PET phantoms for the validation of quantification strategies in oncology

    Energy Technology Data Exchange (ETDEWEB)

    Zito, Felicia; De Bernardi, Elisabetta; Soffientini, Chiara; Canzi, Cristina; Casati, Rosangela; Gerundini, Paolo; Baselli, Giuseppe [Nuclear Medicine Department, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, via Francesco Sforza 35, 20122 Milan (Italy); Bioengineering Department, Politecnico di Milano, piazza Leonardo da Vinci 32, 20133 Milan (Italy) and Tecnomed Foundation, University of Milano-Bicocca, via Pergolesi 33, 20900 Monza (Italy); Bioengineering Department, Politecnico di Milano, piazza Leonardo da Vinci 32, 20133 Milan (Italy); Nuclear Medicine Department, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, via Francesco Sforza 35, 20122 Milan (Italy); Bioengineering Department, Politecnico di Milano, piazza Leonardo da Vinci 32, 20133 Milan (Italy)

    2012-09-15

    Purpose: In recent years, segmentation algorithms and activity quantification methods have been proposed for oncological {sup 18}F-fluorodeoxyglucose (FDG) PET. A full assessment of these algorithms, necessary for a clinical transfer, requires a validation on data sets provided with a reliable ground truth as to the imaged activity distribution, which must be as realistic as possible. The aim of this work is to propose a strategy to simulate lesions of uniform uptake and irregular shape in an anthropomorphic phantom, with the possibility to easily obtain a ground truth as to lesion activity and borders. Methods: Lesions were simulated with samples of clinoptilolite, a family of natural zeolites of irregular shape, able to absorb aqueous solutions of {sup 18}F-FDG, available in a wide size range, and nontoxic. Zeolites were soaked in solutions of {sup 18}F-FDG for increasing times up to 120 min and their absorptive properties were characterized as function of soaking duration, solution concentration, and zeolite dry weight. Saturated zeolites were wrapped in Parafilm, positioned inside an Alderson thorax-abdomen phantom and imaged with a PET-CT scanner. The ground truth for the activity distribution of each zeolite was obtained by segmenting high-resolution finely aligned CT images, on the basis of independently obtained volume measurements. The fine alignment between CT and PET was validated by comparing the CT-derived ground truth to a set of zeolites' PET threshold segmentations in terms of Dice index and volume error. Results: The soaking time necessary to achieve saturation increases with zeolite dry weight, with a maximum of about 90 min for the largest sample. At saturation, a linear dependence of the uptake normalized to the solution concentration on zeolite dry weight (R{sup 2}= 0.988), as well as a uniform distribution of the activity over the entire zeolite volume from PET imaging were demonstrated. These findings indicate that the {sup 18}F

  15. Natural Zeolite Sample and Investigation Its Use in Oil Bleaching Sector

    Science.gov (United States)

    Bilgin, Oyku

    2017-12-01

    In the sector of oil bleaching, the stored raw oil is subjected to physical and chemical methods such as degumming, neutralization, bleaching, deodorization and winterization. In the process of oil bleaching, the selection of correct bleaching earth in accordance with oil characteristics matters so much. Bleaching earth is an inorganic product used in removing impurities being available within the structures of vegetable, animal oil (sunflower, soya, corn, palm, tallow, rapeseed, fish oils…etc.) and fatty acids, mineral oils (glycerine, paraffin, mineral motor oils. etc.) with the adsorption process. The factors such as low cost of oil bleaching earth, low ratio of oil retaining, high bleaching capacity in spite of using them in small amounts, filter’s delayed blocking by the earth and non-increase of the free acidity of the oil should be taken into consideration. Bleaching earths are processed with some acids in order to widen their surface areas. During this process, a certain amount of acid is left within oil bleaching earths even if it is very little. These acids also increase oil’s acidity by oxidizing oil in the course of bleaching process. In this study, zeolite sample taken from Manisa -Demirci region was used. Following the processes of crushing and sieving, zeolite sample was subjected to chemical analyses according to their grain thickness, microscopic examination, the analyses of XRD and cation exchange capacity and their ore characteristics were determined. Afterwards, it was searched whether zeolite sample has oil bleaching ability or not or whether it can be used as oil bleaching earth or not.

  16. Nature and Location of Carbonaceous Species in a Composite HZSM-5 Zeolite Catalyst during the Conversion of Dimethyl Ether into Light Olefins

    Directory of Open Access Journals (Sweden)

    María Ibáñez

    2017-08-01

    Full Text Available The deactivation of a composite catalyst based on HZSM-5 zeolite (agglomerated in a matrix using boehmite as a binder has been studied during the transformation of dimethyl ether into light olefins. The location of the trapped/retained species (on the zeolite or on the matrix has been analyzed by comparing the properties of the fresh and deactivated catalyst after runs at different temperatures, while the nature of those species has been studied using different spectroscopic and thermogravimetric techniques. The reaction occurs on the strongest acid sites of the zeolite micropores through olefins and alkyl-benzenes as intermediates. These species also condensate into bulkier structures (polyaromatics named as coke, particularly at higher temperatures and within the meso- and macropores of the matrix. The critical roles of the matrix and water in the reaction medium have been proved: both attenuating the effect of coke deposition.

  17. Impacts of zero valent iron, natural zeolite and Dnase on the fate of antibiotic resistance genes during thermophilic and mesophilic anaerobic digestion of swine manure.

    Science.gov (United States)

    Zhang, Junya; Sui, Qianwen; Zhong, Hui; Meng, Xiaoshan; Wang, Ziyue; Wang, Yawei; Wei, Yuansong

    2018-06-01

    This study investigated the fate of antibiotic resistance genes (ARGs) during mesophilic (mAD) and thermophilic digestion (tAD) of swine manure through zero valent iron (ZVI), natural zeolite and Dnase addition. Changes of microbial community, intI1, heavy metal resistance genes (MRGs) and virulence factors (VFs) were followed to clarify the influencing factors to ARGs reduction. Results showed that AD could realize ARGs reduction with tAD superior to mAD, and ZVI and natural zeolite could further enhance the reduction, especially for natural zeolite addition at mAD. The reduction efficiency of the relative abundance of ARGs was increased by 33.3% and 138.5% after ZVI and natural zeolite addition, respectively, but Dnase deteriorated ARGs reduction at mAD. Most of ARGs could be reduced effectively except sulII and tetM. Network analysis and partial redundancy analysis indicated that co-occurrence of MRGs followed by microbial community contributed the most to the variation of ARGs fate among treatments. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Evaluation of the potentiality of a Mexican natural zeolite chabazite-type in the lead removal in water; Evaluacion de la potencialidad de una chabasita natural mexicana en la remocion de plomo en agua

    Energy Technology Data Exchange (ETDEWEB)

    Alvarado I, J.; Sotelo L, M.; Meza F, D.; Paz M, F. A. [Universidad de Sonora, Blvd. Luis Encinas y Rosales s/n, Col. Centro, Hermosillo, Sonora (Mexico); Maubert F, M., E-mail: msotelo@guaymas.uson.mx [Universidad Autonoma Metropolitana, Unidad Azcapotzalco, Av. San Pablo 180, Col. Reynosa-Tamaulipas, 02200 Mexico D. F. (Mexico)

    2013-06-01

    The intention of this paper is to present the characterization of a natural zeolite, chabazite-type, from the Mexican reservoir La Palma, at Divisaderos, Sonora, where their potential use as ion exchange material to remove lead in water is assessed. The chabazite was characterized through X-ray diffraction, Icp-OES, Icp-Ms, EDX, Bet and TG/TGD. The results indicate the presence of Ba(1930 ppm) and Sr(1220 ppm), which are characteristic of aluminium rich phases. A chabazite modification treatment is proposed by using solutions of NaOH (0.1 M) and NH{sub 4}NO{sub 3} (1 M). The lead removal kinetics both in natural zeolite as in their chemically modified forms was obtained by using the ion exchange process in a batch reactor. The results show how unnecessary natural zeolite homo ionization is for the removal of lead, thereby obtaining the equilibrium concentration of unmodified zeolite for plotting the adsorption isotherm, which was adjusted to Langmuir model. The Langmuir isotherm has a good fit of the results at equilibrium (R{sup 2}=0.92), which demonstrates that natural zeolites studied, in its natural form, contains exchangeable cations required (Ca{sup +2}, Mg{sup 2+} and Na{sup +}) for potentially be used as an adsorbent material/ion exchanger for water treatment impacted by lead. (Author)

  19. Discerning the Location and Nature of Coke Deposition from Surface to Bulk of Spent Zeolite Catalysts

    Science.gov (United States)

    Devaraj, Arun; Vijayakumar, Murugesan; Bao, Jie; Guo, Mond F.; Derewinski, Miroslaw A.; Xu, Zhijie; Gray, Michel J.; Prodinger, Sebastian; Ramasamy, Karthikeyan K.

    2016-11-01

    The formation of carbonaceous deposits (coke) in zeolite pores during catalysis leads to temporary deactivation of catalyst, necessitating regeneration steps, affecting throughput, and resulting in partial permanent loss of catalytic efficiency. Yet, even to date, the coke molecule distribution is quite challenging to study with high spatial resolution from surface to bulk of the catalyst particles at a single particle level. To address this challenge we investigated the coke molecules in HZSM-5 catalyst after ethanol conversion treatment by a combination of C K-edge X-ray absorption spectroscopy (XAS), 13C Cross polarization-magic angle spinning nuclear magnetic resonance (CP-MAS NMR) spectroscopy, and atom probe tomography (APT). XAS and NMR highlighted the aromatic character of coke molecules. APT permitted the imaging of the spatial distribution of hydrocarbon molecules located within the pores of spent HZSM-5 catalyst from surface to bulk at a single particle level. 27Al NMR results and APT results indicated association of coke molecules with Al enriched regions within the spent HZSM-5 catalyst particles. The experimental results were additionally validated by a level-set-based APT field evaporation model. These results provide a new approach to investigate catalytic deactivation due to hydrocarbon coking or poisoning of zeolites at an unprecedented spatial resolution.

  20. Moderate temperature zeolitic alternation in a cooling pyroclastic deposit

    International Nuclear Information System (INIS)

    Levy, S.S.; O'Neil, J.R.

    1984-01-01

    The locally zeolitized Topopah Spring Member of the Paintbrush Tuff, Yucca Mountain, Nevada, USA is part of a thick sequence of zeolitized pyroclastic units. Most of the zeolitized units are nonwelded tuffs that were altered during low temperature diagenesis, but the distribution and textural setting of zeolite (heulandite-clinoptilolite and smectite in the densely welded Topopah Spring tuff suggests that these hydrous minerals formed while the tuff was still cooling after pyroclastic emplacement and welding. The hydrous minerals are concentrated within a transition zone between devitrified tuff in the central part of the unit and underlying vitrophyre. Movement of liquid and convected heat along fractures from the devitrified tuff to the vitrophyre caused local devitrification and hydrous mineral crystallization. Oxygen isotope geothermometry of cogenetic quartz confirms the nondiagnetic moderate temperature origin of the hydrous minerals at temperatures of about 40 to 100 0 C, assuming a meteoric water source. 14 refs., 3 figs., 1 tab

  1. Flexibility of zeolite frameworks

    Science.gov (United States)

    Kapko, Vitaliy; Treacy, Michael; Thorpe, Michael

    2009-03-01

    Zeolites are an important class of industrial catalysts because of their large internal surfaces and molecular-sieving properties. Recent geometric simulations (1) show that almost all of the known zeolites can exist without distortion of their tetrahedra within some range of densities, which we call the flexibility window. Within this window, the framework accommodates density changes by rotations about the shared tetrahedral corners. We argue that the presence of a flexibility window can be used as a topological criterion to select potential candidates for synthesis from millions of hypothetical structures. We also investigate the exceptions to the rule, as well as the shape of the flexibility window and the symmetric properties of zeolites inside it. (1) A. Sartbaeva, S.A. Wells, M.M.J. Treacy and M.F. Thorpe The flexibility window in zeolites, Nature Materials 5, 962-965 (2006); I. Rivin, commentary 931-932.

  2. The use of zeolites to generate PET phantoms for the validation of quantification strategies in oncology

    International Nuclear Information System (INIS)

    Zito, Felicia; De Bernardi, Elisabetta; Soffientini, Chiara; Canzi, Cristina; Casati, Rosangela; Gerundini, Paolo; Baselli, Giuseppe

    2012-01-01

    Purpose: In recent years, segmentation algorithms and activity quantification methods have been proposed for oncological 18 F-fluorodeoxyglucose (FDG) PET. A full assessment of these algorithms, necessary for a clinical transfer, requires a validation on data sets provided with a reliable ground truth as to the imaged activity distribution, which must be as realistic as possible. The aim of this work is to propose a strategy to simulate lesions of uniform uptake and irregular shape in an anthropomorphic phantom, with the possibility to easily obtain a ground truth as to lesion activity and borders. Methods: Lesions were simulated with samples of clinoptilolite, a family of natural zeolites of irregular shape, able to absorb aqueous solutions of 18 F-FDG, available in a wide size range, and nontoxic. Zeolites were soaked in solutions of 18 F-FDG for increasing times up to 120 min and their absorptive properties were characterized as function of soaking duration, solution concentration, and zeolite dry weight. Saturated zeolites were wrapped in Parafilm, positioned inside an Alderson thorax–abdomen phantom and imaged with a PET–CT scanner. The ground truth for the activity distribution of each zeolite was obtained by segmenting high-resolution finely aligned CT images, on the basis of independently obtained volume measurements. The fine alignment between CT and PET was validated by comparing the CT-derived ground truth to a set of zeolites’ PET threshold segmentations in terms of Dice index and volume error. Results: The soaking time necessary to achieve saturation increases with zeolite dry weight, with a maximum of about 90 min for the largest sample. At saturation, a linear dependence of the uptake normalized to the solution concentration on zeolite dry weight (R 2 = 0.988), as well as a uniform distribution of the activity over the entire zeolite volume from PET imaging were demonstrated. These findings indicate that the 18 F-FDG solution is able to

  3. Anaerobic digestion of palm oil mill effluent with lampung natural zeolite as microbe immobilization medium and digested cow manure as starter

    Science.gov (United States)

    Halim, Lenny; Mellyanawaty, Melly; Cahyono, Rochim Bakti; Sudibyo, Hanifrahmawan; Budhijanto, Wiratni

    2017-05-01

    Indonesia is well-known as the world's biggest palm oil producer with 32.5 million tons of annual production. Palm oil processing contributes to 60% wastewater, leading to environmental problem caused by excessive production of wastewater. This wastewater, i.e. Palm Oil Mill Effluent (POME), has high organic content (40,000-60,000 mg COD/L) which is potential for biogas production. However, its low pH value and long chain fatty acid content likely inhibit the anaerobic digestion. Porous media might reduce the inhibitory effect during POME digestion since the media act as both immobilization media for bacteria and as inhibitor adsorbent. Excessive amount of porous media might interfere with the nutrient consumption by microbes. There will be an optimum amount of porous media added, which depends on the wastewater characteristics. This research studied Lampung natural zeolite as immobilization media in digesting POME. The batch experiment was conducted for 40 days with different amount of natural zeolite, i.e. 0; 45; 100; and 200 g/g COD. Digested cow manure was used as the starter inoculum, considering the abundance of anaerobic bacteria therein. Zeolite addition was proven to accelerate COD reduction and stabilized the volatile fatty acid as the intermediate product of anaerobic digestion. The addition of natural zeolite up to 45 g/g COD is considered enough to increase the COD removal (85.695 %), maintain the methane content up to 50%, and enhance the bacteria activity. However, larger amount of natural zeolite lowered the methane production and COD reduction, which indicated nutrient adsorption on to the media and hence caused decreasing nutrient access by the microbes.

  4. Use of Spent Zeolite Sorbents for the Preparation of Lightweight Aggregates Differing in Microstructure

    Directory of Open Access Journals (Sweden)

    Wojciech Franus

    2017-02-01

    Full Text Available Lightweight aggregates (LWAs made by sintering beidellitic clay deposits at high temperatures, with and without the addition of spent zeolitic sorbents (clinoptilolitic tuff and Na-P1 made from fly ash containing diesel oil, were investigated. Mineral composition of the aggregates determined by X-ray diffraction was highly uniformized in respect of the initial composition of the substrates. The microstructure of the LWAs, which were studied with a combination of mercury porosimetry, microtomography, nitrogen adsorption/desorption isotherms and scanning electron microscopy, was markedly modified by the spent zeolites, which diminished bulk densities, increased porosities and pore radii. The addition of zeolites decreased water absorption and the compressive strength of the LWAs. The spent Na-P1 had a greater effect on the LWAs’ structure than the clinoptilolite.

  5. Pure zeolite exchange to synthetic zeolite characterized by XRD to produce cation exchange materials

    International Nuclear Information System (INIS)

    Zainab Ramli; Dewi Jamaliah Kamsiar; Hasidah Mohd Arsat

    2008-01-01

    In this study, natural mordenite was modified to other zeolites phases having low Si/ Al in order to increase the cation exchange capacity of the material. Modification was carried out hydrothermally at 100 degree Celsius in time range between 0 to 24 hours. The samples obtained were characterized by XRD and infrared spectroscopy. Results showed that a mixture of zeolite X and P were formed zeolite X was the dominant zeolite at 6 hrs heating time while zeolite P were dominant after 6 hrs. Ion Exchange capacity of natural mordenite, samples at 6 hr and 24 hrs heating, performed using Ca 2+ cation gave cation exchange in the decreasing order of 83.57 % , 72.50 %, 69.45 % for sample 24 hrs, 6 hrs and natural mordenite respectively. It indicates that sample having zeolite P phase is the best cation exchange capacity with 21 mg Ca 2+ / g zeolite with an increased of 23 % capacity compared to natural zeolite. (author)

  6. Simultaneous removal of iron and manganese of aqueous solutions using as adsorbent a Mexican natural zeolite;Remocion simultanea de hierro y manganeso de soluciones acuosas utilizando como sorbente una zeolita natural mexicana

    Energy Technology Data Exchange (ETDEWEB)

    Garcia M, A.; Solache R, M. J.; Olguin G, M. T., E-mail: agarciamendieta@yahoo.com.m [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2009-07-01

    In this work was evaluated the removal capacity of iron and manganese of aqueous solutions using a Mexican natural zeolite. It was observed that the Freundlich pattern describes the adsorption process appropriately and that a competitive effect exists between both metals by the exchange places of the zeolite, when it is starting of solutions that contain to both metals, impacting mainly in the manganese removal. A natural zeolite coming from the Puebla State, Mexico was used. The material was milled and sieved to a mesh size 30 and was conditioned with a solution 0.5 N of sodium chloride. Later on was characterized by means of scanning electron microscopy and X-ray diffraction.

  7. Um novo procedimento de síntese da zeólita A empregando argilas naturais A new procedure for a zeolite synthesis from natural clays

    Directory of Open Access Journals (Sweden)

    Reus T. Rigo

    2009-01-01

    Full Text Available This work proposes the synthesis of zeolite A by IZA standard proceedures starting from a natural clay. The clay was used in its natural form and after calcination at 900ºC. The resulting materials were characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM and porosity analysis by nitrogen adsorption. Results showed low surface area for Na-A zeolite in sodium form, but a higher one in CaA based on the nitrogen accessibility. The presence of cubic crystals for the A phase was observed in the SEM micrographies. The new procedure starting from natural clay favors the formation of sodalite while that using the calcinated clay gives A.

  8. Arsenic adsorption in pre-treatment natural zeolite with magnesium oxides; Adsorcion de arsenico en zeolita natural pretratada con oxidos de magnesio

    Energy Technology Data Exchange (ETDEWEB)

    Mejia Z, F. [Universidad Autonoma de Baja California, Instituto de Ingenieria, Blvd. Benito Juarez s/n, 21900 Mexicali, Baja California (Mexico); Valenzuela G, J. L.; Aguayo S, S.; Meza F, D., E-mail: fleridam@iq.uson.m [Universidad de Sonora, Departamentos de Geologia e Ingenieria Quimica y Metalurgia, Blvd. Luis Encinas y Rosales s/n, Col. Centro, 83000 Hermosillo, Sonora (Mexico)

    2009-07-01

    A methodology was developed to modify a natural zeolite (chabazite) with magnesium oxide in order to remove arsenic (As{sup +5}) from water for human consumption. It is proposed a magnesium oxide while regarded as an efficient adsorbent for removing metals in water. X-ray diffraction analyses show significant changes in the chabazite due to the presence of oxides and amorphous hydroxides incorporated during the pre-treatment. Experimental design results show an efficiency greater than 90% of As{sup +5} adsorbed in five minutes. The results indicate that the most significant variables affecting the adsorption of As{sup +5} are the initial concentration of As and the solid/liquid ratio. Experimental data fitted better to Freundlich isotherm with a 20.17 mg/g adsorption capability. (Author)

  9. HIDRORENGKAH METIL ESTER ASAM LEMAK (MEPO MENGGUNAKAN ZEOLIT ALAM TERAKTIVASI HYDROCRACKING OF FATTY ACID METIL ESTER (FAME USING ACTIVATED NATURAL ZEOLITE

    Directory of Open Access Journals (Sweden)

    Lina Mahardiani

    2011-11-01

    Full Text Available Dalam upaya untuk menghasilkan rantai pendek hidrokarbon yang berasal dari minyak sawit, telah dilakukan hidrorengkah metil ester asam lemak (MEPO menggunakan katalis nikel yang diembankan pada zeolit alam aktif (NZA. Zeolit alam (NZ perlakuan asam dilanjutkan dengan kalsinasi selama 1 jam pada suhu 500 oC diperoleh katalis NZA. Impregnasi Ni menggunakan prekusor Ni(NO32.6H2O dilakukan dengan memvariasikan kandungan Ni sebesar 2,5 dan 8% dari berat NZA yang menghasilkan katalis Ni/NZA2, Ni/NZA5 dan Ni/NZA8. Hidrorengkah metil ester asam lemak dilakukan pada reaktor fixed-bed. Kondisi reaksi meliputi waktu retensi 30 menit, laju alir gas hidrogen 20 ml/min dan suhu reaksi 400, 450 dan 500 oC. Produk cair hasil reaksi hidrorengkah dianalisis menggunakan kromatografi gas (GC. Dari proses uji aktivitas katalis didapatkan persentase produk optimum pada jenis katalis Ni/NZA8, yaitu fraksi bensin 29,85% dan fraksi solar 18,03% pada temperatur 500 oC.

  10. Batch-wise adsorption, saxs and microscopic studies of zeolite pelletized with biopolymeric alginate

    Directory of Open Access Journals (Sweden)

    E. Chmielewská

    2011-03-01

    Full Text Available Removal of nitrates, sulfate and Zn(II ions from aqueous solutions through adsorption onto biopolymeric alginate/clinoptilolite-rich tuff pellets was studied by using an equilibrium batch technique. The idea of this approach of biosorbent fabrication is to promote the native zeolite adsorption performance and thus to prepare more efficient amphoteric tailor-made products for specific environmental targets. A flexible component, i.e., alginate biopolymer, and a rigid component (pulverized zeolite were crosslinked using Fe(III and Ca(II chlorides, additively. The extent of adsorption was found to be considerably higher than with the other mostly natural adsorbents examined towards similar pollutants. The equilibrium adsorption data for the above pollutants were satisfactorily fitted to Freundlich and Langmuir isotherms, respectively. According to the linscale SAXS pattern, there was a strong background visible, which may indicate the presence of a considerable amount of biopolymeric phase in the composite samples analysed. Scanning Tunneling, Electron and Atomic Force Microscopies helped visualize their surface texture and morphology.

  11. Removal of emulsified and dissolved traces of organic compounds from industrial wastewaters using nature and synthesized (Na A and Nam) zeolites

    International Nuclear Information System (INIS)

    Modirshahla, N.; Tabatabaii, S.

    2004-01-01

    The main object of this study was to compare the natural and synthetic (Na A 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 objections of the work was: a) to select the best species that have the highest amount of absorption; b) to measure the rate of absorption of traces organic compounds and emulsions on the natural and synthesized zeolites; c) to establish the absorption isotherms for the organics and emulsions with selected samples; d) to select readily available regenerants, and e ) to examine the ph dependence of the process and to establish a simple and practical method to detect and to measure the pollution after the treatment process. The BOD and COD of the treated and feed waters were compared

  12. The effect of zeolite on oxidant/antioxidant status in healthy dairy cows

    Directory of Open Access Journals (Sweden)

    Hudai Ipek

    2012-01-01

    Full Text Available This study was conducted to evaluate the effect of dietary zeolite (clinoptilolite supplementation on the oxidative/antioxidative status on plasma in healthy dairy cows. Twenty dairy cows were divided into two groups of 10. Control group was fed the basal ration for 60 days. Zeolite group was fed the basal ration supplemented with 2.5% zeolite daily. To evaluate the oxidative and antioxidative status comprehensively, indicators such as total oxidant status, oxidative stress index, total antioxidant status, lipid hydroperoxide, total free sulphhydryl groups, ceruloplasmin concentrations, arylesterase, paraoxonase-1 and catalase activities were measured in plasma. Lipid hydroperoxide concentration was significantly (P 2O2 Eq/l by zeolite supplementation. However, no significant effect was observed on the antioxidant and other oxidant indicators. In conclusion, although zeolite decreased the lipid hydroperoxide concentration, it cannot further strengthen antioxidant defense system in healthy dairy cows.

  13. Mineralogy and clinoptilolite K/Ar results from Yucca Mountain, Nevada, USA: A potential high-level radioactive waste repository site

    International Nuclear Information System (INIS)

    WoldeGabriel, G.; Broxton, D.E.; Bish, D.L.; Chipera, S.J.

    1993-11-01

    The Yucca Mountain Site Characterization Project is investigating Yucca Mountain, Nevada, as a potential site for a high-level nuclear waste repository. An important aspect of this evaluation is to understand the geologic history of the site including the diagenetic processes that are largely responsible for the present-day chemical and physical properties of the altered tuffs. This study evaluates the use of K/Ar geochronology in determining the alteration history of the zeolitized portions of Miocene tuffs at Yucca Mountain. Clinoptilolite is not generally regarded as suitable for dating because of its open structure and large ion-exchange capacity. However, it is the most abundant zeolite at Yucca Mountain and was selected for this study to assess the feasibility of dating the zeolitization process and/or subsequent processes that may have affected the zeolites. In this study we examine the ability of this mineral to retain all or part of its K and radiogenic Ar during diagenesis and evaluate the usefulness of the clinoptilolite K/Ar dates for determining the history of alteration

  14. Effect of Lanthanum-Natural Zeolite, La/NZA catalyst on biodiesel production from crude palm oil

    Science.gov (United States)

    Setianingsih, A.; Wisrayetti; Khairat; Bahri, S.

    2018-04-01

    Biodiesel can be produced from vegetable oils through the trans-esterification process. In this study, potential vegetable oil of Crude Palm Oil (CPO) was used as sample. The purposes of this research were to produce biodiesel from CPO as an alternative fuel, having study the ratio of impregnation of Lanthanum on NZA, and its catalyst weight to the biodiesel yield. The La/NZA catalyst is made as followed, first the natural zeolite size was reduced using grinding, then activated using HCl 6 N and NH4Cl 1 N, followed with the drying process. La is impregnated into NZA as solution having variations of 1 and 3% (w/w) of NZA, then it was followed with dried in an oven, calcination, oxidation and reduction. Production of biodiesel is carried out through two stages of esterification and transesterification processes. In the trans-esterification process conducted with the various variation of catalyst weight i.e. 1, 2 and 3% of La/NZA (w/w) for a total weight of 80 grams of CPO sample, having the ratio of oil : methanol 1 : 9. Reaction was lasted for 60 minutes at 60°C having 400 rpm stirring speed. From the result, the conversion of 85.37% is given by the run on using 3% La/NZA catalyst having catalyst weight 1%.

  15. for zeolite coating

    Directory of Open Access Journals (Sweden)

    Carlos Renato Rambo

    2006-01-01

    Full Text Available Biotemplating is the processing of microcellular ceramics by reproduction of natural morphologies, where the microstructural features of the biotemplate are maintained in the biomorphic ceramic. Different biotemplates with distinct pore anatomies were used to produce biomorphic supports for the zeolite coating: wood, cardboard, sea-sponge and sisal. The biomorphic ceramics were produced by distinguished processing routes: Al-gas infiltration-reaction, liquid-metal infiltration, dip-coating and sol-gel synthesis, in order to produce nitrides, carbides and oxides, depending on the processing conditions. The zeolite coating was performed by hydrothermal growth of MFI-type (Silicalite-1 and ZSM-5 zeolite crystals onto the internal pore walls of the biomorphic templates. The final biomorphic ceramic-zeolite composites were physically characterized, evaluated in terms of their gas adsorption capabilities and correlated to their microstructure and specific pore anatomy. The combination of the properties of the biomorphic ceramics with the adsorption properties of zeolites results in materials with distinct properties as potential candidates for adsorption and catalytic applications due to their characteristic porosity, molecular sieving capabilities and high thermo-mechanical strength.

  16. Effect of diverse ions, column temperature and flow rate on the dynamic exchange-properties of cesium in various types of zeolites

    International Nuclear Information System (INIS)

    Mimura, Hitoshi; Kanno, Takuji; Kimura, Toshiya.

    1982-01-01

    The effect of various diverse ions in solution, column temperature and flow rate on the dynamic exchange-properties of Cs have been studied with various types of zeolites, i.e., synthetic mordenite, natural mordenite and clinoptilolite. The concentration of nitric acid considerably affects on the break-through properties of Cs; break-through capacity (B. T. Cap), total capacity (T. Cap) and column utilization (U) decrease with increasing acid concentration. The break-throgh data in the pH range (pH >= 1) are as follows; above 50 (meq./100 g zeolite) for B. T. Cap, 110 (meq./100 g zeolite) for T. Cap and 45 (%) for U, respectively. On the other hand, the concentration of formic acid (<= 2 M) and sodium ion (<= 0.1 M) give no critical change on the break-through properties, and T. Cap was found to be nearly constant. Break-through capacity and exchange rate increase with an increase in column temperature, while T. Cap remains constant. Thus, a similar profile was found in the curves of these properties as a function of temperature. Their inflection point gives the value of C/Co asymptotically equals 0.63. The decrease in flow rate (S. V) appears to give an increase in both B. T. Cap and U. (author)

  17. THE STUDY OF CLINOPTILOLITE MODIFIED WITH3d METALS HALIDES BY IR AND DIFFUSE REFLECTANCE SPECTROSCOPY

    Directory of Open Access Journals (Sweden)

    T. L. Rakitskaya

    2015-11-01

    Full Text Available The results of investigation of natural clinoptilolite (N-CLI and that modified with 3d metal halides (MeCl2/N-CLI, where Me are Cu, Co, and Mn by IR and diffuse reflectance spectroscopy are summarized. A band at 3437 cm-1 assigned to stretching vibrations of hydroxyl groups (nOH is found in the IR spectrum of the N-CLI sample. A location of the band was practically the same as for all above MeCl2/N-CLI samples. A band of middle intensity at 1638 cm-1 in the range of deformation vibrations of zeolite water observed in the IR spectrum of N-CLI slightly displays to lower frequencies in the case of the modified samples. An intensive wide band of a complex shape in the range from 1250 to 980 cm-1 assigned to Si–O–Si and Si–O–Al vibrations appears in IR spectra of all samples. A doublet band of middle intensity at 797 and 778 cm-1 is assigned to external symmetric stretching T-O vibrations and a band at 606 cm-1-to vibrations of a double ring. A location of the above bands is the same for all listed samples but their intensity is higher for MnCl2/N-CLI and CoCl2/N-CLI samples. After the reaction with ozone, significant changes in the IR spectra are observed only for MnCl2/N-CLI. They are due to MnO2 formation on the clinoptilolite surface resulting in a high frequency displacement of some bands. Based on UV-vi spectroscopy results, it is reasonable to make conclusions about the coordination and valence state of a central atom in the MeCl2/N-CLI samples under study. A location of charge transfer bands for these samples only slightly differs from that for N-CLI however the intensity of such bands increases for the MeCl2/N-CLI samples. The UV-vis spectrum of MnCl2/N-CLI changes after the reaction with ozone: the appearance of new bands of  charge transfer at 363 and 354 nm and also the two-fold increase in intensity of a charge transfer band at 272 nm in comparison with those of N-CLI and MnCl2/N-CLI are the evidence of change in both the

  18. Wet impregnation of silver oxide on Lampung natural zeolite as an adsorbent to produce oxygen-enriched air using PSA technique

    Directory of Open Access Journals (Sweden)

    Dianty Adenia Gita

    2018-01-01

    Full Text Available High purity oxygen can be used for various things. Oxygen purification method to be applied on this research is the Pressure Swing Adsorption (PSA technique. The adsorbent that would be used is a natural zeolite, namely ZAL (Zeolite Alam Lampung. Natural zeolite has non-polar properties, so it will adsorb gas with high quadruple moment, which is nitrogen. The varied variable is the size of adsorbent and the concentration of H2SO4. The sizes are 18-35 mesh, 35-60 mesh, and 60-100 mesh. While the H2SO4 concentration are 1M, 2M and 3M. Size of ZAL, and the concentration of sulfuric acid (H2SO4 were varied to get the optimum value. The adsorbent will be activated in aqua demine, H2SO4, NaOH, and through a calcination process. The purpose of this pre-treatment was to remove the impurities and to increase the specific surface area of zeolite. Moreover, ZAL will also be modified by wet impregnation technique using AgNO3 solution with 1%-wt loading nominal. The morphology, composition, and crystal phase were characterized by BET, scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX. The result of the adsorption process was analyzed by using GC (Gas Chromatograph. ZAL 35-60 mesh 1M showed the best performance on adsorbing nitrogen, with its lowest peak at 60356 μV. The result of this research suggested that ZAL itself has the main role on adsorbing nitrogen, while AgxO did not give any significant effect

  19. Immobilization of Co{sup 2+} and Cs{sup +} in zeolites by thermal treatment and by combustion; Inmovilizacion de Co{sup 2+} y Cs{sup +} en zeolitas por tratamiento termico y por combustion

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez T, R.; Bulbulian G, S. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: rosarodtre@yahoo.com

    2005-07-01

    The radioactive waste, either those that take place in the {sup 235}U fission or those that are used in the radiochemical laboratories, are dangerous for the human being and for the one environment. The liquid radioactive wastes are of those that present bigger problem. It has intended to retain by the ion exchange method the radioactive ions of the liquids using, for example, zeolites. In this work so much synthetic zeolites was used (A and X) like a natural zeolite (clinoptilolite). Its were put in contact with cobalt or cesium solutions to simulate radioactive solutions. A part of the zeolite cations were exchanged with cobalt or cesium cations, eliminating them by this way of the solution. However, in extreme conditions these cations can be leached of the solids. To immobilize the cobalt or cesium cations in the zeolites net its are usually carried out thermal treatments to such temperatures that the structure is destroyed and that the contaminating ions are trapped in a solid often vitreous. The exchanged zeolites with cobalt or cesium, on one hand, its were thermally treated to different temperatures during three hours and by the other one, according to the treatment method by combustion, to different temperatures during five minutes in presence of urea, later its were put in contact with a solution of NaCl to measure the leaching of the interest cations. These solutions were analyzed by neutron activation. In general it was found that as the treatment temperature increases (in both methods) the so much immobility of the cesium like of the cobalt it increases. The grade of crystallinity of the samples before and after the treatments it was determined by X-ray diffraction. (Author)

  20. Selectivity of the adsorption process of modified zeolite rock with hexadecyl trimethylammonium bromide in front to chromates and dichromates

    International Nuclear Information System (INIS)

    Salgado G, N.

    2011-01-01

    In the present investigation natural zeolite (clinoptilolite) from the Chihuahua state, which was conditioned with sodium chloride solution and subsequently modified with a hexadecyl trimethylammonium bromide solution was used to evaluate the removal of Cr (Vi) from chromate or dichromate solutions. The zeolite materials were characterized by scanning electron microscopy and X-ray diffraction. The surface area was also determined. The experiments were performed in a batch system, the influence of ph, contact time between phases were investigated and during the adsorption process was calculated the concentration of chromium ion present in aqueous solution (CrO 4 2- , Cr 2 O 7 2- ). The quantification of chromium removed from the aqueous solution by atomic absorption spectrometry technique was done. In order to understand the behaviour of the adsorption kinetics the pseudo first and pseudo second order models were applied, and to determine the adsorption capacity of the zeolite materials for Cr the Langmuir, Freundlich and Langmuir-Freundlich models were chosen. It was found that the removal efficiency of chromium ion is influenced by ph and the chemical species present: chromate or dichromate. The chromate and dichromate sorption kinetic data were best fitted to the pseudo-second and pseudo-first order models, respectively; and the Langmuir and Langmuir-Freundlich models described adequately the isotherms data considering a mono component system. In a mixture of Cr (Vi) ad CrO 4 2- and Cr 2 O 7 2- , the surfactant modified zeolite has a greater selectivity for Cr 2 O 7 2- ion than CrO 4 2- . In this case the Langmuir-Freundlich model described the adsorption isotherm behavior. (Author)

  1. Roles of natural zeolite (clinoptiolite) as a bed medium on growth and body composition of red tilapia (Oreochromis sp.) and lettuce (Lactuca sativa var longifolia) seedlings in a pisciponic system

    OpenAIRE

    Rafiee, Gh.R.; Saad, Ch.R.

    2008-01-01

    Natural zeolite was used as a bed medium for plantation of lettuce seedlings and its effects on growth and chemical composition of red tilapia and lettuce were investigated in a pisciponic system. The place of study was the Aquatic Resources Technology Laboratory, Faculty of Agriculture, at the University Putra Malaysia, in 2002. The mean individual weight and biomass of fish in the treatment with zeolite were significantly higher (P

  2. The effects of an artificially enhanced clinoptilolite in patients with ...

    African Journals Online (AJOL)

    Results: At the end of treatment 67% and 40% of patients were classified as overall responders in the potentiated clinoptilolite and placebo groups respectively (N=50). After week three of treatment the number of weekly responders was significantly higher (p=0.048) in the potentiated clinoptilolite group compared to the ...

  3. Effective removal of Ni(II) from aqueous solutions by modification of nano particles of clinoptilolite with dimethylglyoxime.

    Science.gov (United States)

    Nezamzadeh-Ejhieh, Alireza; Kabiri-Samani, Mehdi

    2013-09-15

    In this work an Iranian natural clinoptilolite tuff was pre-treated and changed to the micro (MCP) and nano (NCP) particles by mechanical method. Modification of micro and nano particles and also their Ni-exchanged forms were done by dimethylglyoxime (DMG). The raw and modified samples were characterized by XRD, FT-IR, SEM, BET, TG-DTG and energy dispersive analysis X-ray spectroscopy (EDAX). Removal of Ni(II) by modified and unmodified samples was investigated in batch procedure. It was found that NCP-DMG has higher capacity for removal of Ni(II). The effects of analytical parameters such as pH, dose of DMG, concentration of nickel solution, contact time and selectivity were studied and the optimal operation parameters were found as follows: pHPZC: 7.6, CNi(II): 0.01 M, contact time: 360 min and DMG dosage: 5mM. The results of selectivity experiments showed that the modified zeolite has a good selectivity for nickel in the presence of different multivalent cations. Langmuir and Freundlich isotherm models were adopted to describe the adsorption isotherms. Adsorption isotherms of Ni(II) ions could be best modelled by Langmuir equation, that indicate the monolayer sorption of Ni(II). Comparison of two kinetic models indicates that the adsorption kinetic can be well described by the pseudo-second-order rate equation that indicates that the rate limiting step for the process involves chemical reaction. The negative ΔH and ΔG indicate an exothermic and spontaneously process. The negative ΔS indicates that the adsorption of nickel cations from solution occurs with lower amount ion replacement, thus chemisorptions due to complex formation are dominant process in nickel removal. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Inhibition of bcl-2 and cox-2 Protein Expression after Local Application of a New Carmustine-Loaded Clinoptilolite-Based Delivery System in a Chemically Induced Skin Cancer Model in Mice

    Directory of Open Access Journals (Sweden)

    Cristina Mihaela Ghiciuc

    2017-11-01

    Full Text Available Our research has focused on in vitro and in vivo evaluations of a new Carmustine (BCNU-loaded clinoptilolite-based delivery system. Two clinoptilolite ionic forms—hydrogen form (HCLI and sodium form (NaCLI—were prepared, allowing a loading degree of about 5–6 mg BCNU/g of zeolite matrix due to the dual porous feature of clinoptilolite. Clinoptilolite-based delivery systems released 35.23% of the load in 12 h for the BCNU@HCLI system and only 10.82% for the BCNU@NaCLI system. The BCNU@HCLI system was chosen to develop gel and cream semisolid dosage forms. The cream (C_BCNU@HCLI released 29.6% of the loaded BCNU after 12 h in the Nylon synthetic membrane test and 31.6% in the collagen membrane test, higher by comparison to the gel. The new cream was evaluated in vivo in a chemically induced model of skin cancer in mice. Quantitative immunohistochemistry analysis showed stronger inhibition of B-cell lymphoma-2 (bcl-2 and cyclooxygenase 2 (cox-2 protein expression, known markers for cancer survival and aggressiveness, after the treatment with C_BCNU@HCLI by comparison to all the control treatment types, including an off-label magistral formula commercially available Carmustine cream as reference, bringing evidence that a clinoptilolite-based delivery systems could be used as a cancer drug carriers and controlled release systems (skin-targeted topical delivery systems.

  5. Mixed-linker zeolitic imidazolate framework mixed-matrix membranes for aggressive CO2 separation from natural gas

    KAUST Repository

    Thompson, Joshua A.

    2014-07-01

    Zeolitic imidazolate framework (ZIF) materials are a promising subclass of metal-organic frameworks (MOF) for gas separations. However, due to the deleterious effects of gate-opening phenomena associated with organic linker rotation near the limiting pore apertures of ZIFs, there have been few demonstrations of improved gas separation properties over pure polymer membranes when utilizing ZIF materials in composite membranes for CO2-based gas separations. Here, we report a study of composite ZIF/polymer membranes, containing mixed-linker ZIF materials with ZIF-8 crystal topologies but composed of different organic linker compositions. Characterization of the mixed-linker ZIFs shows that the mixed linker approach offers control over the porosity and pore size distribution of the materials, as determined from nitrogen physisorption and Horváth-Kawazoe analysis. Single gas permeation measurements on mixed-matrix membranes reveal that inclusion of mixed-linker ZIFs yields membranes with better ideal CO2/CH4 selectivity than membranes containing ZIF-8. This improvement is shown to likely occur from enhancement in the diffusion selectivity of the membranes associated with controlling the pore size distribution of the ZIF filler. Mixed-gas permeation experiments show that membranes with mixed-linker ZIFs display an effective plasticization resistance that is not typical of the pure polymeric matrix. Overall, we demonstrate that mixed-linker ZIFs can improve the gas separation properties in composite membranes and may be applicable to aggressive CO2 concentrations in natural gas feeds. © 2013 Elsevier Inc. All rights reserved.

  6. TWO SOURCES OF ZEOLITE AS SUBSTITUTES OF NITROGEN FERTILIZER FOR WHEAT (Triticum aestivum PRODUCTION IN TLAXCALA, MEXICO

    Directory of Open Access Journals (Sweden)

    Andrés María-Ramírez

    2011-11-01

    Full Text Available Nitrogen is the main nutrient added to the soil for wheat production, but its application increases production costs. Urea is the most used nitrogen fertilizer (NF in Mexico, however only 10 to 60 % is absorbed by crops. To improve this efficiency, the use of slow-release fertilizers has been promoted, although their cost is high compared with traditional nitrogen sources. One alternative to increase the efficiency of NF is the use of minerals such as zeolite. One type of zeolite is the “clinoptilolite”, an aluminum-silicate mineral. The objective of the study was to evaluate two sources of clinoptilolite (Chinobampo and Tehuacán. In four locations, six treatments were established: 1 100 % NF; 2 20 % zeoilte + 80 % NF; 3 40 % zeolite + 60 % NF; 4 60 % zeolite + 40 % NF; 5 80 % zeolite + 20 % NF; and 6 100 % zeolite. In treatments 2, 4 and 6 the seeds were mycorrhized before sowing. On average, treatment 3 yielded 2.9 ton ha-1, followed by treatment 2 with 2.6 ton ha-1, which yielded 2.3 and 3.0 ton ha-1 with zeolite Chinobampo and Tehuacán, respectively.

  7. Nature of the Cu+ -NO bond in the gas phase and at different types of Cu+ sites in zeolite catalysts

    Czech Academy of Sciences Publication Activity Database

    Davidová, M.; Nachtigallová, Dana; Nachtigall, Petr

    2004-01-01

    Roč. 108, - (2004), s. 13674-13682 ISSN 1520-6106 R&D Projects: GA MŠk LN00A032 Institutional research plan: CEZ:AV0Z4055905 Keywords : HFCC calculations * zeolite * NO Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.834, year: 2004

  8. The Effect of Synthesis Conditions and Nature of Heteroelement on Acidic Properties of Isomorphously Substituted UTL Zeolites

    Czech Academy of Sciences Publication Activity Database

    Shamzhy, Mariya; Shvets, O. V.; Opanasenko, Maksym; Vitvarová, Dana; Nachtigall, P.; Čejka, Jiří

    2013-01-01

    Roč. 1, č. 1 (2013), s. 103-113 ISSN 2327-3941 R&D Projects: GA ČR GBP106/12/G015; GA ČR GAP106/11/0819 Institutional support: RVO:61388955 Keywords : Extra-Large Pore Zeolite * Isomorphous Substitution * Brønsted and Lewis Acidity Subject RIV: CF - Physical ; Theoretical Chemistry

  9. The effect of natural zeolite as microbial immobilization media in anaerobic digestion at various concentrations of palm oil mill effluent (POME)

    Science.gov (United States)

    Ayu, Erika Dyah; Halim, Lenny; Mellyanawaty, Melly; Sudibyo, Hanifrahmawan; Budhijanto, Wiratni

    2017-05-01

    Anaerobic digestion is one of the solutions in POME treatment because it generates energy in the form of biogas. Nevertheless, high concentration of POME fed into the digester will cause high acidification level and eventually cause process failure. The failure can also be affected by high inhibitor concentration contained in POME, one of which is long chain fatty acid. The addition of immobilization media is commonly used to increase the bacteria resistance to inhibitor. Natural zeolite is considered as appropriate immobilization media for waste treatment purpose since it is cheap, has high mechanical strength, high immobilization capacity, and its ability as cation exchanger. The digested biodiesel waste was used as starter inoculum for its good capability in digesting oil-containing feed such as POME. This research was conducted to evaluate critical concentration of POME fed to digester where the natural zeolite could not reduce the inhibitory effect. The concentrations of POME evaluated were 10,000 mg sCOD/L and 17,000 mg sCOD/L, which were higher than previous studies(5,000 to 8,000 mg sCOD/L). The research showed that at such high sCOD concentrations, the addition of zeolite did not significantly increase COD reduction nor biogas production rate, for both POME concentrations to be compared to control. The biogas produced by digester fed by 10,000 mg/L POME and 17,000 mg/L POME was 751 and 100 mL/g sCOD, respectively, indicating higher inhibitor effect in the digester with 17,000 mg SCOD/L initial concentration.

  10. CATALYTIC HYDROCRACKING OF WASTE LUBRICANT OIL INTO LIQUID FUEL FRACTION USING ZnO, Nb2O5, ACTIVATED NATURAL ZEOLITE AND THEIR MODIFICATION

    Directory of Open Access Journals (Sweden)

    Wega Trisunaryanti

    2010-06-01

    Full Text Available Catalytic hydrocracking of waste lubricant oil into liquid fuel fraction using ZnO, Nb2O5, activated natural zeolite (ZAAH and their modification has been investigated. The zeolite was produced in Wonosari, Yogyakarta. Activation of the zeolite was carried out by refluxing with HCl 3M for 30 min, produced the activated natural zeolite (ZAAH. The ZnO/ZAAH catalyst was prepared by impregnation of Zn onto the ZAAH by ion exchange method using salt precursor of Zn(NO32.4H2O. The Nb2O5/ZAAH catalyst was prepared by mixing the ZAAH sample with Nb2O5 and oxalic acid solution until the paste was formed. The impregnation of Zn onto Nb2O5/ZAAH was carried out using the same method to that of the ZnO/ZAAH catalyst resulted ZnO/Nb2O5-ZAAH catalyst. Characterization of catalyst includes determination of Zn metal by Atomic Absorption Spectroscopy (AAS, acidity by gravimetric method and catalyst porosity by Surface Area Analyzer (NOVA-1000. Catalytic hydrocracking was carried out in a semi-batch reactor system using ZnO, ZAAH, ZnO/ZAAH and ZnO/Nb2O5-ZAAH catalysts at 450 oC under the H2 flow rate of 15 mL/min. and the ratio of catalyst/feed = 1/5. The composition of liquid products was analyzed by Gas Chromatograpy (GC.The results showed that impregnation of ZnO and/or Nb2O5 on the ZAAH increased the acidity and specific surface area of catalyst. The products of the hydrocracking process were liquid, coke and gas. Conversion of liquid products was increased by the increase of catalyst acidity. The highest liquid product was produced by ZnO/Nb2O5-ZAAH catalyst, 52.97 wt-%, consist of gasoline, 38.87 wt-% and diesel, 14.10 wt-%.   Keywords: hydrocracking, waste lubricant oil, liquid fuel fraction

  11. The effects of clinoptilolite on piglet and heavy pig production

    Directory of Open Access Journals (Sweden)

    Archimede Mordenti

    2010-01-01

    Full Text Available To evaluate the effects of clinoptilolite on piglet and heavy pig production two separated trials have been performed. In the first trial 40 pigs of the initial body weight of 55 kg were used. Animals were homogeneously allocated to two groups: a control group traditionally fed and a clinoptilolite group in which feed contained the additive at 2%. Pigs were slaugh- tered at about 160 kg body weight. Blood samples were taken to determine blood urea nitrogen (BUN. In the second trial a total of 116 piglets from 12 litters was used. Six litters were fed from the 7th day of life a diet containing clinoptilolite at 2%. According to the dietary treatment of the suckling period, 84 weaned piglets were homogeneously allocated to two groups fed up to 33 kg body weight a diet containing or not clinoptilolite at 2%. In both trials daily weight gain, feed intake and pigs’ health were regularly recorded. The dietary inclusion of clinoptilolite at 2% did not resulted in any modification either of growing performances or of uraemia. Piglets on clinoptilolite diet showed a significant (P<0.05 improvement of faecal dry matter content. At slaughtering the dietary inclusion of clinoptilolite resulted in a trend towards an improvement of lean cuts yield and in a significant increase (P<0.05 of the ratio between lean and fat cuts. From our data it is sug- gested that clinoptilolite does not impair pig growing performances, determines a higher dry matter content of piglet fae- ces and improves carcass quality of heavy pigs with particular regard to lean cuts yield and lean to fat cuts ratio.

  12. Usig of clinoptilolite for feeding dogs of different breeds

    OpenAIRE

    Kaušinytė, Rasa

    2014-01-01

    Aims of the study: to evaluate the efficacy of clinoptilolite to overal wellness, changes made to GI tract microflora and digestibility of food substances for large, middle and small sized dogs. Objectives: 1. to perform household experiments with dogs of different breed before giving clinoptilolite and during various periods; 2. to evaluate consumption of food and different food substances during different growing periods; 3. to assess clinoptilolite’s composition and tendencies ...

  13. Adsorption of Indigo Carmine Dye Using Cetyltrimethylammonium Bromide (CTAB) Surfactant Modified Zeolite

    OpenAIRE

    Fauziyah, Nurul; Sriatun, Sriatun; Pardoyo, Pardoyo

    2015-01-01

    Research of indigo carmine dye adsorption using natural zeolite modified by cetyltrimethylammonium bromide (CTAB) surfactant has been done. The purpose of this study was to modify the natural zeolite using CTAB surfactant and to determine its ability on the adsorption of indigo carmine dye. The stages of the study included the activation of zeolites, modifying zeolites using CTAB surfactant and adsorption test of indigo carmine dye. The results showed that the zeolites could be modified by CT...

  14. Boron adsorption on hematite and clinoptilolite

    International Nuclear Information System (INIS)

    Gainer, G.M.

    1993-01-01

    This thesis describes experiments performed to determine the suitability of boron as a potential reactive tracer for use in saturated-zone C-well reactive tracer studies for the Yucca Mountain Project (YMP). Experiments were performed to identify the prevalent sorption mechanism of boron and to determine adsorption of boron on hematite and clinoptilolite as a function of pH. These minerals are present in the Yucca Mountain tuff in which the C-well studies will be conducted. Evaluation of this sorption mechanism was done by determining the equilibration time of boron-mineral suspensions, by measuring changes in equilibrium to titrations, and by measuring electrophoretic mobility. Experiments were performed with the minerals suspended in NaCl electrolytes of concentrations ranging from 0.1 N NaCl to 0.001 N NaCl. Experimentalconditions included pH values between 3 and 12 and temperature of about 38 degrees C

  15. The combination of activated natural zeolite-bentonite to reduce Fe and Cu in refined bleached palm oil (RBPO) by using atomic absorption spectrophotometer method

    Science.gov (United States)

    Zakwan; Raja, PM; Giyanto

    2018-02-01

    Indonesia is one of the crude palm oil (CPO) production country in the world. As many products are derivated from the CPO, the quality must be increased continuously. One of the things that influence the quality of palm oil is the Fe and Cu content. The objective of this research was to reduce Fe and Cu content in Refined Bleached Palm Oil (RBPO). In processing CPO or Refined Bleachead Palm Oil (RBPO) may be contaminated by Fe and Cu from metal tank and pipe in the factory. The zeolite and bentonite was activated by maceration method using hydrochloric acid (0,1 N). Four batch reactions consisting of refined palm oil (RPO), activated natural zeolite-bentonite (ANZB) was bleached by heating and stirring them at about 105°C and 1200 rpm for 30 minutes. The results showed that all combinations of ANZB can reduce the Fe content. Thereafter, the optimal combination of ANZB was obtained in K1, K2 and K4 with Cu content 0.02 ppm. In the future, it is needed to study on the reduction of the Fe and Cu content in palm oil with the other adsorbent.

  16. Sorption of {sup 239}Np and {sup 235}U fission products by zeolite Y, Mexican natural erionite, and bentonite

    Energy Technology Data Exchange (ETDEWEB)

    Olguin, M.T.; Solache, M.; Iturbe, J.L. [Instituto Nacional de Investigaciones Nucleares, C.P. (Mexico)]|[Universidad Autonoma Metropolitana, C.P. (Mexico)] [and others

    1996-09-01

    Zeolite Y, erionite, and bentonite have been used in this work to remove {sup 239}Np and {sup 235}U fission products from aqueous solutions at various pH values. It was found that the sorption of fission products by aluminosilicates takes place by different mechanisms, mainly ion exchange, precipitation, and electrostatic surface interaction. The radionuclides content was determined by {gamma}-spectrometry, and X-ray diffraction was used to learn whether the solids maintained their crystallinity at different pH values.

  17. The spatial distribution and chemical heterogeneity of clinoptilolite at Yucca Mountain, Nye County, Nevada: Evidence for polygenetic hypogene alteration

    International Nuclear Information System (INIS)

    Livingston, D.E.; Szymanski, J.S.

    1994-01-01

    This part of TRAC's Annual Report for 1993 summarizes the finding of previous reports on the major element geochemistry of zeolitic alteration of the tuffs at Yucca Mountain and updates the status of work. In this report we examine the spatial distribution of zeolites by stratigraphic units and boreholes and the various types of chemical alteration of clinoptilolite indicated by the data reported in Broxton et al. and Bish and Chipera. The purpose is to evaluate the extent of the metasomatic alteration and to test the hypogene hypothesis of Szymanski. In this regard, it is of prime importance to evaluate whether the metasomatic alteration at Yucca Mountain is due to supergene or hypogene processes. In this report, the term open-quotes supergeneclose quotes denotes alteration and mineralization produced by fluids derived directly from atmospheric precipitation and infiltration through the vadose zone, and the term open-quotes hypogeneclose quotes denotes alteration and mineralization produced by fluids from the phreatic zone regardless of their former location or residence time in the Earth's crust. This report begins with a review of previous work on the genesis of zeolites of the Nevada Test Site

  18. Influence of Zeolite on fatty acid composition and egg quality in Tunisian Laying Hens

    Directory of Open Access Journals (Sweden)

    Fendri Imen

    2012-06-01

    Full Text Available Abstract Background The health benefits of omega-3 and omega-6 polyunsaturated fatty acids (PUFA are generally recognized. Unfortunately, in most Mediterranean countries, the recommended daily intake of these compounds is rarely met. Therefore, enrichment of commonly occurring foods can boost intake of these fatty acids. In this regard, eggs are an interesting target, as they form an integral part of the diet. Result Zeolite (Clinoptilolites was added to Laying Hens feed at concentrations 1% or 2% and was evaluated for its effects on performance of the production and on egg quality. The Laying Hens were given access to 110 g of feed mixtures daily that was either a basal diet or a ‘zeolite diet’ (the basal diet supplemented with clinoptilolite at a level of 1% or 2%. It was found that zeolite treatment had a positive and significatif (p  Conclusion This study showed the significance of using zeolite, as a feed additive for Laying Hens, as part of a comprehensive program to control egg quality and to increase level of polyunsaturated fatty acids on egg.

  19. In vitro and in vivo tests for determination of the pathogenicity of quartz, diatomaceous earth, mordenite and clinoptilolite.

    Science.gov (United States)

    Adamis, Z; Tátrai, E; Honma, K; Six, E; Ungváry, G

    2000-01-01

    The effects of samples of crystalline quartz, diatomaceous earth, mordenite and clinoptilolite were investigated in vitro (as concerns erythrocyte haemolysis and lactate dehydrogenase (LDH) release from peritoneal macrophages) and in vivo (on LDH, protein and phospholipids in rat bronchoalveolar lavage (BAL), and phospholipids in rat lung tissue). The respirable mineral samples were instilled intratracheally. Determinations in the BAL were carried out after 15, 60 and 180 days, and in the lung tissue after 90, 180 and 360 days. Quartz DQ and quartz FQ induced acute, subacute and chronic inflammation and progressive fibrosis. However, due to the Al2O3 contamination on the surface of the particles quartz FQ caused a delayed response in vivo. Diatomaceous earth produced acute/subacute inflammation that gradually became more moderate after 60 days. Clinoptilolite was inert, whereas the other zeolite sample, mordenite, was cytotoxic in vivo. The reason for this was presumably the needle and rod-shaped particles in the mordenite samples. The investigation revealed that different in vitro and in vivo methods canprovide valuable data concerning the pulmonary toxicity of minerals.

  20. Applicability of zeolites in potassium and nitrate retention in different soil types

    Directory of Open Access Journals (Sweden)

    Pavlović Jelena B.

    2017-01-01

    Full Text Available Environmental protection and sustainable agricultural production require the use of inexpensive and environmentally acceptable soil supplements. Objectives of this study were to investigate the influence of the addition of the natural zeoliteclinoptilolite (NZ and its iron(III-modified form (FeZ on the potassium and nitrate leaching from sandy, silty loam and silty clay soils. The zeolites were added in two amounts: 0.5 (FeZ and 1.0 wt. % (NZ and FeZ. The experiments were carried out in columns organized in eight experimental systems containing unamended (control specimens and amended soils. The concentration of K+ and NO3–N in the leachates was monitored during 7 days. The obtained results indicate that the K+ and NO3–N leaching mainly depends on the soil type and pH of the soil. The NZ and FeZ addition has the highest impact on the K+ retention in the acidic sandy soil. The highest NO3–N retention is obtained with FeZ in acidic silty loam soil. The K+ leaching kinetics for all the studied soils follow the Avrami kinetics model with the parameter n < 1. This study demonstrates that NZ and FeZ can be a good soil supplement for the K+ retention for all studied soils and in the NO3–N retention for silty loam and silty clay soils. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 172018

  1. Performance evaluation of an anaerobic fluidized bed reactor with natural zeolite as support material when treating high-strength distillery wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, N. [Renewable Energy Technology Center (CETER), ' ' Jose Antonio Echeverria' ' Polytechnical University, Calle 127 s/n, CP 19390, Apdo. 6028, Habana 6 Marianao, Ciudad de La Habana (Cuba); Montalvo, S. [Department of Chemical Engineering, Santiago de Chile University, Ave. Lib. Bernardo O' Higgins 3363, Santiago de Chile (Chile); Borja, R.; Travieso, L.; Raposo, F. [Instituto de la Grasa (CSIC), Avenida Padre Garcia Tejero 4, 41012 Sevilla (Spain); Guerrero, L. [Department of Chemical, Biotechnological and Environmental Processes, Federico Santa Maria Technical University, Casilla 110-V, Valparaiso (Chile); Sanchez, E.; Colmenarejo, M.F. [Centro de Ciencias Medioambientales (CSIC), C/Serrano, 115-Duplicado, 28006 Madrid (Spain); Cortes, I. [Environment Nacional Center, Chile University, Ave. Larrain 9975, La Reina, Santiago de Chile (Chile)

    2008-11-15

    The performance of two laboratory-scale fluidized bed reactors with natural zeolite as support material when treating high-strength distillery wastewater was assessed. Two sets of experiments were carried out. In the first experimental set, the influences of the organic loading rate (OLR), the fluidization level (FL) and the particle diameter of the natural zeolite (D{sub P}) were evaluated. This experimental set was carried out at an OLR from 2 to 5 g COD (chemical oxygen demand)/l d, at FL 20% and 40% and with D{sub P} in the range of 0.2-0.5 mm (reactor 1) and of 0.5-0.8 mm (reactor 2). It was demonstrated that OLR and FL had a slight influence on COD removal, whereas they had a strong influence on the methane production rate. The COD removal was slightly higher for the highest particle diameter used. The second experimental set was carried out at an OLR from 3 to 20 g COD/l d with 25% of fluidization and D{sub P} in the above-mentioned ranges for reactors 1 and 2. The performance of the two reactors was similar; no significant differences were found. The COD removal efficiency correlated with the OLR based on a straight line. COD removal efficiencies higher than 80% were achieved in both reactors without significant differences. In addition, a straight line equation with a slope of 1.74 d{sup -1} and an intercept on the y-axis equal to zero described satisfactorily the effect of the influent COD on the COD removal rate. It was also observed that both COD removal rate and methane production (Q{sub M}) increased linearly with the OLR, independently of the D{sub P} used. (author)

  2. AKTIVASI ZEOLIT ALAM SEBAGAI ADSORBEN PADA ALAT PENGERING BERSUHU RENDAH

    Directory of Open Access Journals (Sweden)

    Laeli Kurniasari

    2012-04-01

    Full Text Available ACTIVATION OF NATURAL ZEOLITE AS AN ADSORBENT FOR LOW TEMPERATURE DRYING SYSTEM. Drying is one process which is used in many industries, especially in food product. The process usually still has low energy efficiency and can make food deterioration because of the usage of high temperature. One alternative in drying technology is the use of zeolite as a water vapor adsorbent. This kind of drying method make it possible to operate in lower temperature, hence it will be suitable for heat sensitive product. Natural zeolit can be one promising adsorbent since it is spreadly abundant in Indonesia. Natural zeolite must be activated first before used, in order to get zeolite with high adsorption capacity. Activation process in natural zeolite will change the Si/Al ratio, polarity, and affinity of zeolite toward water vapor and also increase the porosity. Activation of natural zeolite can be done with two methods, chemical activation use NaOH and physical activation use heat. In the activation using NaOH, natural zeolite is immersed with NaOH solution 0.5-2N in 2 hour with temperature range 60-900C. The process is continued with the drying of zeolite in oven with 1100C for 4 hours. While in heat treatment, zeolit is heated into 200-5000C in furnace for 2-5 hours. SEM analysis is used to compare the change in zeolite morphology before and after each treatment, while to know the adsorption capacity of zeolite, the analyses were done in many temperature and relative humidity. Result gives the best condition in NaOH activation is NaOH 1N and temperature 700C, with water vapor loading is 0.171 gr/gr adsorbent. In heat treatment, the best condition is 3000C and 3 hours with loading 0.137 gr water vapor/gr adsorbent.  Pengeringan merupakan salah satu proses yang banyak digunakan pada produk pangan. Proses ini umumnya menyebabkan kerusakan pada bahan pangan, disamping masih rendahnya efisiensi energi. Salah satu alternatif pada proses pengeringan yaitu

  3. Selectivity of the adsorption process of modified zeolite rock with hexadecyl trimethylammonium bromide in front to chromates and dichromates; Selectividad del proceso de adsorcion de roca zeolitica modificada con bromuro de hexadeciltrimetilamonio frente a cromatos y dicromatos

    Energy Technology Data Exchange (ETDEWEB)

    Salgado G, N.

    2011-07-01

    In the present investigation natural zeolite (clinoptilolite) from the Chihuahua state, which was conditioned with sodium chloride solution and subsequently modified with a hexadecyl trimethylammonium bromide solution was used to evaluate the removal of Cr (Vi) from chromate or dichromate solutions. The zeolite materials were characterized by scanning electron microscopy and X-ray diffraction. The surface area was also determined. The experiments were performed in a batch system, the influence of ph, contact time between phases were investigated and during the adsorption process was calculated the concentration of chromium ion present in aqueous solution (CrO{sub 4}{sup 2-}, Cr{sub 2}O{sub 7}{sup 2-}). The quantification of chromium removed from the aqueous solution by atomic absorption spectrometry technique was done. In order to understand the behaviour of the adsorption kinetics the pseudo first and pseudo second order models were applied, and to determine the adsorption capacity of the zeolite materials for Cr the Langmuir, Freundlich and Langmuir-Freundlich models were chosen. It was found that the removal efficiency of chromium ion is influenced by ph and the chemical species present: chromate or dichromate. The chromate and dichromate sorption kinetic data were best fitted to the pseudo-second and pseudo-first order models, respectively; and the Langmuir and Langmuir-Freundlich models described adequately the isotherms data considering a mono component system. In a mixture of Cr (Vi) ad CrO{sub 4}{sup 2-} and Cr{sub 2}O{sub 7}{sup 2-}, the surfactant modified zeolite has a greater selectivity for Cr{sub 2}O{sub 7}{sup 2-} ion than CrO{sub 4}{sup 2-}. In this case the Langmuir-Freundlich model described the adsorption isotherm behavior. (Author)

  4. Solubility and cation exchange in phosphate rock and saturated clinoptilolite mixtures

    Science.gov (United States)

    Allen, E. R.; Hossner, L. R.; Ming, D. W.; Henninger, D. L.

    1993-01-01

    Mixtures of zeolite and phosphate rock (PR) have the potential to provide slow-release fertilization of plants in synthetic soils by dissolution and ion-exchange reactions. This study was conducted to examine solubility and cation-exchange relationships in mixtures of PR and NH4- and K-saturated clinoptilolite (Cp). Batch-equilibration experiments were designed to investigate the effect of PR source, the proportion of exchangeable K and NH4, and the Cp to PR ratio on solution N, P, K, and Ca concentrations. The dissolution and cation-exchange reactions that occurred after mixing NH4- and K-saturated Cp with PR increased the solubility of the PR and simultaneously released NH4 and K into solution. The more reactive North Carolina (NC) PR rendered higher solution concentrations of NH4 and K when mixed with Cp than did Tennessee (TN) PR. Solution P concentrations for the Cp-NC PR mixture and the Cp-TN PR mixture were similar. Solution concentrations of N, P, K, and Ca and the ratios of these nutrients in solution varied predictably with the type of PR, the Cp/PR ratio, and the proportions of exchangeable K and NH4 on the Cp. Our research indicated that slow-release fertilization using Cp/PR media may provide adequate levels of N, P, and K to support plant growth. Solution Ca concentrations were lower than optimum for plant growth.

  5. Possibilities of utilizing zeolites for the reduction of toxical noxious gases of combustion engines

    Directory of Open Access Journals (Sweden)

    Pandová Iveta

    2001-12-01

    Full Text Available Combustion engines produce exhalations that contribute by 50% to the contamination of the environment. The subject of this work is the research of zeolites´ as the adsorbent of toxical gases. The decisive influence on the adsorbing power has the capacity of porous in unit of volume of the sorbent and dimensions of canals. The active component of zeolite from the deposit Bystré is mineral clinoptilolite. Recently, there is an increased interest to utilize zeolites in the partial reduction of NOx, CO and hydrocarbons in the combustion products. The catalysts used to detoxication of exhalation combustion engines are less effective during periods of relatively low temperature operation, such as the initial cold-start period of engine operation. Some European, American and Japones patents are directed to the use of a zeolite catalyst for the reduction of hydrocarbons, CO and NOx. The noble metals and acid zeolites are used as a catalyst of noxious components. The adsorbent material, which may be a zeolite is part treatment system in order to adsorb gaseous pollutants during of cold start period of engine operation.

  6. Sorption phenomena of modification of clinoptilolite tuffs by surfactant cations.

    Science.gov (United States)

    Rozić, M; Ivanec Sipusić, D; Sekovanić, L; Miljanić, S; Curković, L; Hrenović, J

    2009-03-15

    The sorption of cationic surfactant hexadecyltrimethylammonium (HDTMA) onto the solid/liquid interfaces of different clinoptilolite rich tuffs (CT) is examined. Examined were CT from Serbia with 75% clinoptilolite, CT from Turkey with 70% clinoptilolite, and CT from Croatia with 60% clinoptilolite. The sorption of HDTMA cations increased in the following order: CT from Serbia>CT from Turkey>CT from Croatia. The maximum amounts of sorbed HDTMA cations, normalized with regard to external cation exchange capacities of tuffs, were 1.79, 1.70, and 1.14 for Serbian, Turkish, and Croatian CT. FTIR analysis of samples with the maximum amount of sorbed HDTMA cations showed that HDTMA chains on Serbian CT adopt mainly a stretched all-trans conformation, while at the surfaces of CT from Turkey and Croatia the amount of gauche conformations increased. The zeta potentials of CT samples with the maximum amount of sorbed HDTMA cations and the sorption of benzoate anions on these samples increased in the following order: CT from Turkey>CT from Serbia>CT from Croatia. It can be assumed that on the surface of CT from Turkey iron (hydr)oxide clusters or nanoparticles with positive surface sites are present, due to which the isoelectric point is sifted toward lower and the zeta potential toward higher values. Therefore, the sorption of benzoate anions on modified CT from Turkey is also higher.

  7. Removal of indigo blue using clinoptilolite-Fe

    International Nuclear Information System (INIS)

    Gutierrez S, E. E.; Colin C, A.; Solache R, M. J.

    2008-01-01

    The removal of indigo blue from aqueous solutions was evaluated using modified clinoptilolite with Fe (Z-Fe) which was characterized by SEM, EDS analysis and specific area (BET). The process followed the kinetics of pseudo-second order and Langmuir isotherm. Sorption capacity obtained was 18 mg g -1 and a solid-liquid ratio 10 g L -1 . (Author)

  8. Zeolite and swine inoculum effect on poultry manure biomethanation

    DEFF Research Database (Denmark)

    Kougias, Panagiotis; Fotidis, Ioannis; Zaganas, I.D.

    2013-01-01

    Poultry manure is an ammonia-rich substrate that inhibits methanogenesis, causing severe problems to the anaerobic digestion process. In this study, the effect of different natural zeolite concentrations on the mesophilic anaerobic digestion of poultry waste inoculated with well-digested swine...... manure was investigated. A significant increase in methane production was observed in treatments where zeolite was added, compared to the treatment without zeolite.Methane production in the treatment with 10 g dm-3 of natural zeolite was found to be 109.75% higher compared to the treatment without...... zeolite addition. The results appear to be influenced by the addition of zeolite, which reduces ammonia toxicity in anaerobic digestion and by the ammonia-tolerant swine inoculum....

  9. Zeolites as candidate materials for aqueous tritiated waste storage

    International Nuclear Information System (INIS)

    Todorovic, M.; Radak-Jovanovic, Z.; Gal, I.J.; Brucher, H.

    1987-01-01

    Zeolites have been considered as storage materials for aqueous tritiated waste, owing to their relatively high water contents, low diffusion coefficient of water in their pores and their accessibility. The diffusion coefficient of tritiated water in the solid particles seems to be the most important factor in the selection of zeolites for tritiated water storage. This work summarizes investigations done in The Boris Kidric Institute and Juelich Nuclear Research Center on zeolites as storage materials for tritiated water. Modified 4A zeolites as CsA, ZnA, CoA, Fe(III)A, as well as synthetic and natural analcime, have been investigated. Self-diffusion coefficients of THO in zeolites have been calculated using the Boyd-Reichenberg model of diffusion. The results obtained are discussed from the point of view of using zeolites as storage materials for tritiated waste water. In this respect, natural and synthetic analcime seem to be promising

  10. Dyes adsorption blue vegetable and blue watercolor by natural zeolites modified with surfactants;Adsorcion de colorantes azul vegetal y azul acuarela por zeolitas naturales modificadas con surfactantes

    Energy Technology Data Exchange (ETDEWEB)

    Jardon S, C. C.; Olguin G, M. T. [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Diaz N, M. C., E-mail: teresa.olguin@inin.gob.m [Instituto Tecnologico de Toluca, Av. Instituto Tecnologico s/n, Ex-Rancho la Virgen, 52140 Metepec, Estado de Mexico (Mexico)

    2009-07-01

    In this work was carried out the dyes removal blue vegetable and blue watercolor of aqueous solutions, to 20 C, at different times and using a zeolite mineral of Parral (Chihuahua, Mexico) modified with hexadecyl trimethyl ammonium bromide or dodecyl trimethyl ammonium bromide. The zeolite was characterized before and after of its adaptation with NaCl and later with HDTMABr and DTMABr. For the materials characterization were used the scanning electron microscopy of high vacuum; elementary microanalysis by X-ray spectroscopy of dispersed energy and X-ray diffraction techniques. It was found that the surfactant type absorbed in the zeolite material influences on the adsorption process of the blue dye. Likewise, the chemical structure between the vegetable blue dye and the blue watercolor, determines the efficiency of the color removal of the water, by the zeolites modified with the surfactants. (Author)

  11. Intestinal Development and Function of Broiler Chickens on Diets Supplemented with Clinoptilolite

    Directory of Open Access Journals (Sweden)

    Q. J. Wu

    2013-07-01

    Full Text Available The purpose of this study was to evaluate the effect of natural clinoptilolite (NCLI and modified clinoptilolite (MCLI on broiler performance, gut morphology, intestinal length and weight, and gut digestive enzyme activity. A total of 240 d-old male chicks were randomly assigned to 3 treatments, each of which comprised 8 pens of 10 chicks per pen. Birds in the control group were fed the basal diet, while those in the experimental groups were fed diets supplemented with NCLI at 2% (NCLI group, or MCLI at 2% (MCLI group, respectively, for 42 d. Compared with the control, supplementation with NCLI or MCLI had no significant (p>0.05 effects on productive parameters from d 1 to 42. Supplementation with NCLI or MCLI had no influence on the relative length and weight of small intestine at d 1 to 21. But supplementation with NCLI or MCLI significantly reduced the relative weight of duodenum. Supplementation with MCLI and NCLI was associated with greater (p0.05 influence on the crypt depth in the jejunal and ileal mucosa compared with those in the controls. The addition of either NCLI or MCLI to the diet improved the activities of total protease, and amylase in the small intestinal contents. In conclusion, supplementation with NCLI or MCLI in diets improved intestinal morphology, increased the intestinal length and weigh and gut digestive enzyme activity.

  12. Influence of zeolite nanofillers on properties of polymeric materials

    OpenAIRE

    Kopcová, M.; Ondrušová, D.; Krmela, J.; Průša, P.; Pajtášová, M.; Jankurová, Z.

    2012-01-01

    The present work deals with the preparation and study of modified polymeric materials with the replacement of carbon black by nanofillers on the basis of zeolite that is environmentally friendly. Natural zeolites from a group of aluminosilicate nanoporous materials have wide range of possibilities for applications that are environmentally friendly. Zeolites can be used in the role of fillers into the polymer materials too [1]. The given work deals with the preparation and study of modif...

  13. Aqueous interactions of zeolitic material in acidic and basic solutions

    OpenAIRE

    Polatoğlu, İlker; Çakıcıoğlu Özkan, Seher Fehime

    2010-01-01

    Aqueous interactions of natural zeolitic material in as-received and modified forms were studied. The zeolitic materials was interacted with acidic (hydrochloric acid, lactic acid, acetic acid) and basic (sodium hydroxide) solutions. Ion exchange, adsorption, complex formation, precipitation and cation hydrolysis were possible interaction mechanisms affected by the amount and cation content of zeolite and pH. The dominant mechanisms seemed to be ion exchange and adsorption in HCl solution whe...

  14. Estudo da síntese da zeólita ZSM-5 a partir de argilas naturais Study of ZSM-5 zeolite synthesis from natural clays

    Directory of Open Access Journals (Sweden)

    Marcelo L. Mignoni

    2007-02-01

    Full Text Available The synthesis of ZSM-5 zeolite was studied by three synthesis methods: standard synthesis, three day synthesis and synthesis employing clays (kaolin and montmorillonite. The raw materials and prepared materials were characterized by Chemical Analysis by X-Ray Fluorescence (XRF and X-Ray Diffraction (XRD. The results show that it is possible to synthesized ZSM-5 zeolite using clays as raw materials. Kaolin gives phases of higher crystalinity than montmorillonite.

  15. Adsorption of nicotine on different zeolite types, from aqueous solutions

    Directory of Open Access Journals (Sweden)

    Stošić Dušan K.

    2007-01-01

    Full Text Available The plant alkaloid, nicotine, is a strongly toxic heterocyclic compound: the lethal dose for an adult human being (40-60 mg is importantly lower in comparison with the other known poisons such as arsenic or strychni­ne. Cigarettes represent "the most toxic and addictive form of nicotine". Besides the negative effects of nicotine on public health produced by self-administration, recently another potentially very dangerous effect has been recognized: because of its miscibility with water, nicotine can be found in industrial wastewaters, and consequently, in groundwater. Therefore, the problem of nicotine removal from aqueous solutions has became an interesting topic. In this work, the removal of nicotine has been probed by adsorption on solid materials. Adsorption of nicotine on different zeolites (clinoptilolite, ZSM-5 and β zeolite and on activated carbon was investigated from aqueous solutions, at 298 K. The obtained results are presented as adsorption isotherms: the amount of adsorbed nicotine as a function of equilibrium concentration. These data were obtained from the residual amount of nicotine in the aqueous phase, by the use of UV spectroscopy. The highest amounts of adsorbed nicotine was found for activated carbon and p zeolite (~ mmol·g-1. The attempt to modify the adsorption properties of ZSM-5 zeolite has been also done: ZSM-5 was modified by ion-exchange with VIII group metal (Cu2+ and Fe3+. In addition, the adsorption of nicotine on ZSM-5 zeolite with different Si/Al ratios has been done. It has been noticed that ion-exchange did not improve the adsorption possibilities, while the adsorption was importantly lower in the case of higher silicon content in ZMS-5 structure. 13C NMR spectra were collected for suspensions formed of solid adsorbent and aqueous solution of nicotine; in this way, the part of nicotine molecule which is most probably connected with the adsorbent was recognized.

  16. Comparative study of activated carbon, natural zeolite, and green sand supports for CuOX and ZnO sites as ozone decomposition catalyst

    Science.gov (United States)

    Azhariyah, A. S.; Pradyasti, A.; Dianty, A. G.; Bismo, S.

    2018-03-01

    This research was based on ozone decomposition in industrial environment. Ozone is harmful to human. Therefore, catalysts were made as a mask filter to decompose ozone. Comparison studies of catalyst supports were done using Granular Activated Carbon (GAC), Natural Zeolite (NZ), and Green Sand (GS). GAC showed the highest catalytic activity compared to other supports with conversion of 98%. Meanwhile, the conversion using NZ was only 77% and GS had been just 27%. GAC had the highest catalytic activity because it had the largest pore volume, which is 0.478 cm3/g. So GAC was used as catalyst supports. To have a higher conversion in ozone decomposition, GAC was impregnated with metal oxide as the active site of the catalyst. Active site comparison was made using CuOX and ZnO as the active site. Morphology, composition, and crystal phase were analyzed using SEM-EDX, XRF, and XRD methods. Mask filter, which contained catalysts for ozone decomposition, was tested using a fixed bed reactor at room temperature and atmospheric pressure. The result of conversion was analyzed using iodometric method. CuOX/GAC and ZnO/GAC 2%-w showed the highest catalytic activity and conversion reached 100%. From the durability test, CuOX/GAC 2%-w was better than ZnO/GAC 2%-w because the conversion of ozone to oxygen reached 100% with the lowest conversion was 70% for over eight hours.

  17. Removal of Bisphenol A aqueous solution using surfactant-modified natural zeolite: Taguchi's experimental design, adsorption kinetic, equilibrium and thermodynamic study.

    Science.gov (United States)

    Genç, Nevim; Kılıçoğlu, Ödül; Narci, Ali Oğuzhan

    2017-02-01

    In this study, surfactant-modified natural zeolite was used to remove Bisphenol A (BPA) from aqueous solutions. Kinetics, equilibrium and thermodynamics of BPA adsorption on the adsorbent surfaces were investigated. The experimental data were described with the Temkin isotherm and the pseudo-second- order kinetic model. Taguchi's robust design approach was used to optimize adsorption of BPA. Experimentation was planned as per Taguchi's L27 orthogonal array. Tests were conducted with different adsorbate amount, pH, time, initial concentration of BPA, temperature and agitation speed. The optimum levels of control factors for maximum total organic carbon removal were defined (adsorbate amount at 0.25 g, pH at 7, time at 30 min, initial concentration of BPA at 50 mg/L, temperature at 30°C and agitation speed at 200 rpm). The ANOVA analysis shown that the most effective control factor is adsorbent dosage; its contribution is 56.4%. Contribution of pH and mixing rate are 7.5% and 7.6%, respectively. A confirmation experiment was conducted to verify the feasibility and effectiveness of the optimal combination. The observed value of S/N (η obs  = 39) ratio is compared with that of the predicted value (η opt  = 48). The prediction error, that is, η opt  - η obs  = 9, is within CI value.

  18. The effect of supercritical isobutane regeneration on the nature of hydrocarbons deposited on a USY zeolite catalyst utilized for isobutane/butene alkylation

    Energy Technology Data Exchange (ETDEWEB)

    Daniel M. Ginosar; Lucia M. Petkovic

    2004-11-01

    The chemical nature of hydrocarbons remaining on an ultrastable Y-zeolite (USY) utilized for liquid phase isobutane/butene alkylation reaction at 333 K and 1.1x107 Pa before and after supercritical isobutane regeneration (SFR) at 453 K and 1.1x107 Pa are presented. Catalyst samples were deactivated to different levels by running the alkylation reaction for different times on stream (TOS) and regenerated under flowing supercritical isobutane for 60 min. Nitrogen physisorption, temperature-programmed oxidation (TPO), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), and ultraviolet-visible (UV-Vis) spectroscopy measurements suggested that the SFR process was effective in recovering catalyst surface area and micropore volume and that most coke precursors were removed from samples regenerated after short TOS, when the level of activity for trimethylpentanes (TMP) production was high. Samples that were allowed to react for longer TOS contained unsaturated hydrocarbons that, instead of being extracted by the supercritical fluid, dehydrogenated during the SFR process to produce more condensed species.

  19. Geological, mineralogical and geochemical characteristics of zeolite deposits associated with borates in the Bigadiç, Emet and Kirka Neogene lacustrine basins, western Turkey

    Science.gov (United States)

    Gündogdu, M. N.; Yalçin, H.; Temel, A.; Clauer, N.

    1996-09-01

    The Bigadiç, Emet and Kirka lacustrine basins of western Turkey may be considered as Tibet-type graben structures that were developed during the Miocene within the Izmir-Ankara suture zone complex. The volcanic-sedimentary successions of these basins are made up of mudstone, carbonate (limestone and dolomite) and detrital rocks, and also of crystal or vitric tuffs about 135 to 200 m thick. The Degirmenli (Bigadiç), Emirler (Bigadiç) Köpenez (Emet) and Karaören (Kirka) tuffs constituting the zeolite deposits are situated beneath four borate deposits (colemanite, ulexite, borax). The most abundant diagenetic silicate minerals are K- and Ca-clinoptilolites in the zeolite deposits, and Li-rich trioctahedral smectites (stevensite, saponite and hectorite) and K-feldspar in the borate deposits. In the Degirmenli, Emirler, Köpenez and Karaören deposits, the following diagenetic facies were developed from rhyolitic glasses rich in K and poor in Na: (glass+smectite), (K-clinoptilolite+opal-CT), (Ca-clinoptilolite+K-feldspar±analcime± quartz) and (K-feldspar+analcime+quartz). K-feldspar which is also rarely associated with phillipsite (Karaören) and heulandite (Degirmenli and Karaören), succeeds clinoptilolite and precedes analcime in these diagenetic facies where dioctahedral smectites, opal-CT and quartz are the latest minerals. No diagenetic transformations exist between clinoptilolite, K-feldspar and analcime that were formed directly from glass. The lateral facies distributions resulted from the differences in salinity and pH of pore water trapped during deposition of the tuffs, but vertical distributions in vitric tuffs seem to have been controlled by the glass/liquid ratio of the reacting system and the permeability or diffusion rate of alkali elements. The Bigadiç, Emet and Kirka zeolite deposits which were formed in saline basins rich in Ca and Mg ions, show similar chemical changes, i.e. loss of alkalis and gain in alkaline-earth elements that have taken

  20. Clinoptilolite compositions in diagenetically-altered tuffs at a potential nuclear waste repository, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Broxton, D.E.

    1987-01-01

    The compositions of Yucca Mountain clinoptilolites and their host tuffs are highly variable. Clinoptilolites and heulandites in fractures near the repository and in a thin, altered zone at the top of the Topopah Spring basal vitrophyre have consistent calcium-rich compositions. Below this level, clinoptilolites in thick zones of diagenetic alteration on the east side of Yucca Mountain have calcic-potassic compositions and become more calcium rich with depth. Clinoptilolites in stratigraphically equivalent tuffs to the west have sodic-potassic compositions and become more sodic with depth. Clinoptilolite properties important for repository performance assessment include thermal expansion/contraction behavior, hydration/dehydration behavior, and ion-exchange properties. These properties can be significantly affected by clinoptilolite compositions. The compositional variations for clinoptilolites found by this study suggest that the properties will vary vertically and laterally at Yucca Mountain. Used in conjunction with experimental data, the clinoptilolite compositions presented here can be used to model the behavior of clinoptilolites in the repository environment and along transport pathways

  1. Comparison of the defluoridation capacity of zeolites from Ethiopia ...

    African Journals Online (AJOL)

    Fluorosis, either dental or skeleton, is often due to the high fluoride content of well waters. In this work, using solutions which contain different amounts of fluoride, natural zeolites from Ethiopia and Mexico were tested. It is shown that, although zeolites are known to be cationic exchangers, their extra-framework aluminum ...

  2. FUNDAMENTALS AND APPLICATIONS OF PERVAPORATION THROUGH ZEOLITE MEMBRANES

    Science.gov (United States)

    Zeolite membranes are well suited for separating liquid-phase mixtures by pervaporation because of their molecular-sized pores and their hydrophilic/hydrophobic nature, and the first commercial application of zeolite membranes has been for dehydrating organics [1]. Because of ...

  3. Immobilization of copper flotation waste using red mud and clinoptilolite.

    Science.gov (United States)

    Coruh, Semra

    2008-10-01

    The flash smelting process has been used in the copper industry for a number of years and has replaced most of the reverberatory applications, known as conventional copper smelting processes. Copper smelters produce large amounts of copper slag or copper flotation waste and the dumping of these quantities of copper slag causes economic, environmental and space problems. The aim of this study was to perform a laboratory investigation to assess the feasibility of immobilizing the heavy metals contained in copper flotation waste. For this purpose, samples of copper flotation waste were immobilized with relatively small proportions of red mud and large proportions of clinoptilolite. The results of laboratory leaching demonstrate that addition of red mud and clinoptilolite to the copper flotation waste drastically reduced the heavy metal content in the effluent and the red mud performed better than clinoptilolite. This study also compared the leaching behaviour of metals in copper flotation waste by short-time extraction tests such as the toxicity characteristic leaching procedure (TCLP), deionized water (DI) and field leach test (FLT). The results of leach tests showed that the results of the FLT and DI methods were close and generally lower than those of the TCLP methods.

  4. Effect of zeolites on chitosan/zeolite hybrid membranes for direct methanol fuel cell

    Science.gov (United States)

    Wang, Jingtao; Zheng, Xiaohong; Wu, Hong; Zheng, Bin; Jiang, Zhongyi; Hao, Xiaopeng; Wang, Baoyi

    Zeolites including 3A, 4A, 5A, 13X, mordenite, and HZSM-5 were incorporated into chitosan (CS) matrix to fabricate the hybrid membranes for direct methanol fuel cell (DMFC). Due to the presence of hydrogen bonds between CS and zeolite, the hybrid membranes displayed desirable thermal and mechanical stabilities. Through free volume characteristics analysis by positron annihilation lifetime spectroscopy (PALS) technique, it was found that incorporation of hydrophilic zeolites would increase the free volume cavity size whereas incorporation of hydrophobic zeolites would decrease the free volume cavity size. Through the investigations on water/methanol uptake, swelling, and methanol permeability, it was found that the membrane performance was highly dependent on the zeolite particle and pore size, content, and hydrophilic/hydrophobic nature. Based on the solution-diffusion mechanism, it was found that incorporation of hydrophobic zeolites increased the diffusion resistance of methanol and consequently decreased the methanol permeability, whereas incorporation of hydrophilic zeolites decreased the diffusion resistance of methanol and consequently increased the methanol permeability. Moreover, under the identical conditions, all the as-prepared membranes exhibited much lower methanol permeability than Nafion ® 117 while the proton conductivity of the membranes remained high enough for DMFC applications.

  5. Synthesis and characterization of zeolite material from coal ashes modified by surfactant

    International Nuclear Information System (INIS)

    Fungaro, D.A.; Borrely, S.I.

    2010-01-01

    Coal ash was used as starting material for zeolite synthesis by means of hydrothermal treatment. The surfactant-modified zeolite (SMZ) was prepared by adsorbing the cationic surfactant hexadecyltrimethylammonium bromide (HDTMA-Br) on the external surface of the zeolite from coal ash. The zeolite structure stability was monitored during the characterization of the materials by FTIR, XDR and SEM. The structural parameters of surfactant-modified zeolite are very close to that of corresponding non-modified zeolite which indicates that the crystalline nature of the zeolite remained intact after required chemical treatment with HDTMA-Br molecules and heating treatment for drying. The most intense peaks in the FTIR spectrum of HDTMA-Br were observed in SMZ spectrum confirming adsorption of surfactant on zeolites. (author)

  6. Human bile sorption by cancrinite-type zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Linares, Carlos F. [Laboratorio de Catalisis y Metales de Transicion, Facultad de Ciencias y Tecnologia, Departamento de Quimica, Universidad de Carabobo, Valencia. Edo. Carabobo, Apartado Postal 3336 (Venezuela, Bolivarian Republic of)], E-mail: clinares@uc.edu.ve; Colmenares, Maryi; Ocanto, Freddy [Laboratorio de Catalisis y Metales de Transicion, Facultad de Ciencias y Tecnologia, Departamento de Quimica, Universidad de Carabobo, Valencia. Edo. Carabobo, Apartado Postal 3336 (Venezuela, Bolivarian Republic of); Valbuena, Oscar [Facultad de Ciencias y Tecnologia, Departamento de Biologia, Universidad de Carabobo, Valencia. Edo. Carabobo, Apartado Postal 3336 (Venezuela, Bolivarian Republic of)], E-mail: ovalbuena@uc.edu.ve

    2009-01-01

    A nitrated cancrinite-type zeolite was synthesized from zeolite X, NaOH and NaNO{sub 3} solutions under autogeneous pressure at 80 deg. C for 48 h. This zeolite was characterized by X-ray diffraction (XRD), FT-IR-spectroscopy, scanning electron microscopy (SEM) and BET surface area. XRD, SEM and FT-IR confirmed the presence of nitrated cancrinite-type zeolite without other collateral phases as sodalite. Then, this sodium zeolite was exchanged with potassium and calcium cations and finally, these modified zeolites were reacted with biliar solutions from human gallbladder. Several factors such as: mass of used cancrinite, nature of the exchanged cation and reaction time of the cancrinite-bile solution interactions were studied. The composition of bile solutions (bile acids, phospholipids and bilirubin) was analyzed before and after the cancrinite-bile solution reaction. Results showed that the components of the bile were notably reduced after the contact with solids. Ca-cancrinite, 120 min of reaction time and 500 mg of solids were the best conditions determined for the bile acid reduction in human bile. When the modified zeolites were compared with the commercial cholestyramine, it was found that zeolites were more active than the latter. These zeolites may be an alternative choice to diminish cholesterol levels in hypercholesterolemic patients.

  7. Hydrothermal synthesis of free-template zeolite T from kaolin

    Science.gov (United States)

    Arshad, Sazmal E.; Yusslee, Eddy F.; Rahman, Md. Lutfor; Sarkar, Shaheen M.; Patuwan, Siti Z.

    2017-12-01

    Free-template zeolite T crystals were synthesized via hydrothermal synthesis by utilizing the activated kaolin as silica and alumina source, with the molar composition of 1 SiO2: 0.04 Al2O3: 0.26 Na2O: 0.09 K2O: 14 H2O. Observation of the formation of free-template zeolite crystals were done at temperature 90°C, 100 °C and 110 °C respectively. It was therefore determined that during the 120 h of the synthesis at 90 °C, zeolite T nucleated and formed a first competitive phase with zeolite L. As temperature increases to 100 °C, zeolite T presented itself as a major phase in the system at time 168 h. Subsequently, development of Zeolite T with second competitive phase of zeolite W was observed at temperature 110 °C. In this study, XRD and SEM instruments were used to monitor the behavior of zeolite T crystals with respect of temperature and time. By using natural resource of kaolin clay as a starting material, this paper hence aims to provide new findings in synthesis of zeolite T using low energy consumption and low production cost.

  8. [Biodegradation and adsorption of bio-zeolite on pyridine and quinoline].

    Science.gov (United States)

    Bai, Yao-Hui; Sun, Qing-Hua; Xing, Rui; Wen, Dong-Hui; Tang, Xiao-Yan

    2010-09-01

    The study was to explore the treatment of pyridine, quinoline and their transformation product, NH(4+) -N, by the biodegradation and adsorption of a natural and a modified bio-zeolites. The experiment results demonstrated that the mixed bacteria on the bio-zeolites, a pyridine-degrading bacterium and a quinoline-degrading bacterium, could degrade pyridine and quinoline simultaneously. The NH(4+) -N transformed from pyridine and quinoline could be adsorbed by the natural and modified zeolites. The adsorption capacity of the modified zeolite was lower than that of the natural zeolite. However, more microorganisms could attach on the surface of the modified zeolite, so the application of the modified bio-zeolite has a better prospect in actual treatment of pyridine and/ or quinoline pollution.

  9. A comparative study of two aging and fusion methods in the synthesis of zeolitic materials from natural clinker

    Directory of Open Access Journals (Sweden)

    Jeimer Alexander Lizcano-Cabeza

    2015-01-01

    Full Text Available Una muestra de clínker natural colombiano fue evaluado como mat erial de partida para una síntesis a escala de laboratorio de m ateriales zeolíticos usando dos métodos d e fusión alcalina seguida de dos métodos de envejecimiento y finalmente un tratamiento hidrotér mico bajo tres periodos de tiempo distintos. La fusión se llevó a cabo us ando NaOH sólido y en solución, siendo seguida por envejecimien to en condiciones estáticas o de ultras onido. El proceso finalizó con una reacción hidrotérmica. El c línker natural fue convertido e n varios materiales zeolíticos. Las características de los materiales ze olíticos resultantes y los efectos de las variaciones experimen tales son discutidos.

  10. Catalysis with hierarchical zeolites

    DEFF Research Database (Denmark)

    Holm, Martin Spangsberg; Taarning, Esben; Egeblad, Kresten

    2011-01-01

    zeolites that have been reported hitherto. Prototypical examples from some of the different categories of catalytic reactions that have been studied using hierarchical zeolite catalysts are highlighted. This clearly illustrates the different ways that improved performance can be achieved with this family...

  11. A comparative study of two aging and fusion methods in the synthesis of zeolitic materials from natural clinker

    OpenAIRE

    Jeimer Alexander Lizcano-Cabeza; Luis Fernando Ávila-Ascanio; Carlos Alberto Ríos-Reyes; Luz Yolanda Vargas-Fiallo

    2015-01-01

    Una muestra de clínker natural colombiano fue evaluado como mat erial de partida para una síntesis a escala de laboratorio de m ateriales zeolíticos usando dos métodos d e fusión alcalina seguida de dos métodos de envejecimiento y finalmente un tratamiento hidrotér mico bajo tres periodos de tiempo distintos. La fusión se llevó a cabo us ando NaOH sólido y en solución, siendo seguida por envejecimien to en condiciones estáticas o de ultras onido. El proceso finalizó con una reacción hidr...

  12. Possibility of Modification of Zeolites by Iron Oxides and its Utilization for Removal of Pb(II from Water Solutions

    Directory of Open Access Journals (Sweden)

    Michal Lovás

    2004-12-01

    Full Text Available Ion-exchange properties of cations from lattice and ions from solutions are characteristic for zeolites. Zeolites as sorbents are used in many branches of industry. Ion-exchange reactions of cations on zeolites have been a theme of many works. With the exception of using natural zeolites as the sorbent, a modification of surface of zeolites and preparation of synthetic zeolites has received interest lately. One of the common modification of zeolites is modification by iron oxides, which increases capacity of adsorption. In this work, we prepared a modified zeolite by the precipitation of magnetite on the surface of zeolite. This new adsorbent was used to remove of Pb(II from waste water. The maximum adsorption capacity was 73,25 mg/g from the solution of Pb with the concentration of 400 mg/l.

  13. The study on effect of zeolite on nitrogen use efficiency of corn by 15N-isotope dilution method

    International Nuclear Information System (INIS)

    Li Changhong; Li Huaxing; Zhang Xinming; Liu Yuanjin

    2002-01-01

    A pot experiment was carried out to study the effect of natural zeolite on nitrogen use efficiency of corn by using 15 N-isotope dilution method. The results showed that application of zeolite could improve the corn growth and enhance the biomass of the corn seedling. By using zeolite, nitrogen use efficiency (NUE) of corn was increased by 23.2%-33.1% as compared with no-zeolite treatment; and the residual nitrogen has no significant difference between zeolite treatment and no-zeolite treatment

  14. Zeolite thin films: from computer chips to space stations.

    Science.gov (United States)

    Lew, Christopher M; Cai, Rui; Yan, Yushan

    2010-02-16

    Zeolites are a class of crystalline oxides that have uniform and molecular-sized pores (3-12 A in diameter). Although natural zeolites were first discovered in 1756, significant commercial development did not begin until the 1950s when synthetic zeolites with high purity and controlled chemical composition became available. Since then, major commercial applications of zeolites have been limited to catalysis, adsorption, and ion exchange, all using zeolites in powder form. Although researchers have widely investigated zeolite thin films within the last 15 years, most of these studies were motivated by the potential application of these materials as separation membranes and membrane reactors. In the last decade, we have recognized and demonstrated that zeolite thin films can have new, diverse, and economically significant applications that others had not previously considered. In this Account, we highlight our work on the development of zeolite thin films as low-dielectric constant (low-k) insulators for future generation computer chips, environmentally benign corrosion-resistant coatings for aerospace alloys, and hydrophilic and microbiocidal coatings for gravity-independent water separation in space stations. Although these three applications might not seem directly related, they all rely on the ability to fine-tune important macroscopic properties of zeolites by changing their ratio of silicon to aluminum. For example, pure-silica zeolites (PSZs, Si/Al = infinity) are hydrophobic, acid stable, and have no ion exchange capacity, while low-silica zeolites (LSZs, Si/Al zeolites that have not been exploited before, such as a higher elastic modulus, hardness, and heat conductivity than those of amorphous porous silicas, and microbiocidal capabilities derived from their ion exchange capacities. Finally, we briefly discuss our more recent work on polycrystalline zeolite thin films as promising biocompatible coatings and environmentally benign wear-resistant and

  15. Increasing levels of zeolite and Yucca schidigera in diets for adult cats

    Directory of Open Access Journals (Sweden)

    Natália Charleaux Roque

    2011-11-01

    Full Text Available The effect of the additives Yucca schidigera (YSC and zeolite (clinoptilolite on digestibility, fecal texture and odor, blood parameters and urine pH of domesticated felines was evaluated. The experiment was conducted in a randomized block design, with twenty-one cats, in two periods, distributed in seven treatments: moist commercial feed (control; control + 125, 250 and 375 ppm YSC; and control + 0.5; 0.75 and 1.0 % zeolite. No differences were observed between the diets regarding apparent digestibility coefficients of nutrient, energy, urine pH or blood parameters. However, levels of 0.5 and 0.75% zeolite were effective both in reducing odor (R² = 96.39 and for fecal texture (R² = 99.63, showing a quadratic pattern for these variables. Levels of 125 and 375 ppm YSC were also efficient in reducing fecal odor; however they did not adjust to regression. Levels of 0.5% and 0.75% zeolite significantly reduce odor of feces and increase fecal texture when added to commercial feed for cats.

  16. Production performance of dairy cows after the dietary addition of clinoptilolite

    Directory of Open Access Journals (Sweden)

    Luisa Casini

    2010-01-01

    Full Text Available Clays are frequently proposed for the addition to dairy cattle diets to reduce the transfer of mycotoxins in milk. This study  examined the effect of the addition of Clinoptilolite to the diet of lactating dairy cows on milk production and milk com-  position. Thirty-two lactating Holstein cows (average lactation length: 142 d were blocked according to milk production,  parity, and days of lactation for assignment to one of two dietary treatments: control diet; control diet + Clinoptilolite,  200g/d. The control diet was based on corn and alfalfa silages, hay and concentrates, and did not contain aflatoxins above  the safe level. The experimental period lasted 76 days. The Clinoptilolite supplementation did not affect milk yield and  milk composition other than urea contents. The urea level in milk was negatively affected by Clinoptilolite addition (con-  trol group 29.7 mg/100 ml vs Clinoptilolite group 31.3 mg/100ml. The dietary addition of Clinoptilolite did not change  pH, ammonia content and VFA molar percentages in the rumen. No dietary effect on mineral contents of blood plasma  (Na, K, Zn, and Ca was observed. In case of clinoptilolite use in dairy cattle feeding, scarce negative effect on milk pro-  duction and quality are expected. 

  17. Ammonia-nitrogen and phosphates sorption from simulated reclaimed waters by modified clinoptilolite

    International Nuclear Information System (INIS)

    Huo, Hanxin; Lin, Hai; Dong, Yingbo; Cheng, Huang; Wang, Han; Cao, Lixia

    2012-01-01

    Highlights: ► The salt and thermally modified clinoptilolite can effectively sorb NH 3 -N and phosphates. ► The phosphorus and nitrogen removal was consistent with Langmuir isotherm model. ► The modified clinoptilolite possesses rapid adsorption and slow balance characteristics. ► The adsorption is more in line with the Elovich adsorption dynamics equation. ► The entropy effect plays the role of the main driving force in the adsorption. - Abstract: This paper presents the investigation of the ammonia-nitrogen and phosphates sorption from simulated reclaimed wastewater by modified clinoptilolite. The results showed that the modified clinoptilolite has a high sorption efficiency and removal performance. The ammonia-nitrogen and phosphates removal rate of the modified clinoptilolite reached to 98.46% and 99.80%, respectively. The surface of modified clinoptilolite became loose and some pores appeared, which enlarged the specific surface area; the contents of Na and Fe increased, and the contents of Ca and Mg decreased. The modified clinoptilolite possesses rapid sorption and slow balance characteristics and ammonia-nitrogen and phosphates sorption is more consistent with the Langmuir isotherm model. The adsorption kinetics of ammonia-nitrogen and phosphates follows the Elovich adsorption dynamics equation, which describes the sorption of ammonia-nitrogen and phosphates in aqueous solution as mainly a chemical sorption. Results from the thermodynamics experiment involving ammonia-nitrogen and phosphates sorption reveal that the process is a spontaneous and endothermic process, and is mainly driven by entropy effect.

  18. Yield and quality of maize grown on a loamy soil amended with natural chabazite zeolitite

    Directory of Open Access Journals (Sweden)

    Dario Di Giuseppe

    2015-12-01

    Full Text Available The agronomic use of natural zeolite is widely supported by several works. However, almost all are focused on the application of the clinoptilolite as slow plant-nutrient fertilizer and soil conditioner. Our study describes the first comprehensive study on the effects of a Italian chabazite-bearing zeolitite (rocks containing more than 50% of zeolites on a maize cultivation. The objective was to determine the effects of applying zeolitite on (i Zea mays yield and quality, under two irrigation regimes and (ii check if it can improve the efficiency of urea fertilization on a loamy soil in an open experimental field of Italy. The production and quality of the corn grown in the traditional way was compared with that of the plots treated with two different amounts of zeolitite (4 and 8 Kg/m2 and each treatment was monitored both in irrigated and not-irrigated conditions. The measurements of chlorophyll and those related to the morphological features of the plants show suffering conditions of the corn plants in not-irrigated conditions. Furthermore we show that the plants grown with zeolitite and fertilized with less urea have produced the same amounts of corn plants fertilized with traditional contents of urea.

  19. Removal of pyridine and quinoline by bio-zeolite composed of mixed degrading bacteria and modified zeolite

    International Nuclear Information System (INIS)

    Bai Yaohui; Sun Qinghua; Xing Rui; Wen Donghui; Tang Xiaoyan

    2010-01-01

    In the process of the biodegradation of pyridine and quinoline, ammonium is often generated because of the transformation of N from pyridine and quinoline. Zeolite has been proven to be an effective sorbent for the removal of the ammonium. The natural zeolite can be modified to be the macroporous carrier in the biological wastewater treatment process. In this study, a specific bio-zeolite composed of mixed bacteria (a pyridine-degrading bacterium and a quinoline-degrading bacterium) and modified zeolite was used for biodegradation and adsorption in two types of wastewater: sterile synthetic and coking wastewater. The experimental results indicated that pyridine and quinoline could be degraded simultaneously by the mixed bacteria. Furthermore, NH 4 + -N transformed from pyridine and quinoline could be removed by the modified zeolite. In addition, the bacterial community structures of the coking wastewater and the bio-zeolite were monitored by the amplicon length heterogeneity polymerase-chain reaction (LH-PCR) technique. Both LH-PCR results and scanning electron microscope (SEM) observations indicated that the microorganisms, including BW001 and BW003, could be easily attached on the surface of the modified zeolite and that the bio-zeolite could be used in the treatment of wastewater containing pyridine and/or quinoline.

  20. Zeolites modified with silver for the development of a water disinfection system

    International Nuclear Information System (INIS)

    Aparicio V, S.

    2013-01-01

    In spite of great strides that have been taken in sanitation technologies, there still exist health problems due to microbiological contamination by water. The waterborne diseases have not been completely eradicated and are a big problem of economic interest and health. Moreover, the microbicidal properties of silver have been used for a long time. The use of silver as a disinfectant has many advantages; for example it inhibits a wide spectrum of microorganisms, it has oligo dynamic properties and owing its mechanisms of cell inactivation, it also does not allow the emergence of new resistant strains. In the present research, the kinetics of water disinfection with silver has been investigated, to develop small system for water disinfection, based in silver modified Mexican clinoptilolite. The chemical species of silver play a significant role in the disinfection processes. For this reason, in this work, were both the Ag + and nanoparticles of Ag ο considered. The synthesis of nanoparticles of Ag ο woes performed by thermal and chemical reduction. It was found that the chemical reduction of Ag + to Ag ο was more efficient because it presented more defined nano structures and better distribution than those of thermal reduction. Clinoptilolite of Taxco (Guerrero) was chosen to exchange the native ions from the clinoptilolite by Ag + from the aqueous medium, or to deposit the nanoparticles of Ag ο on this surface. These silver modified zeolitic materials were characterized by scanning electron microscopy (Sem), elemental analyses (EDS), X-ray diffraction (XRD) and neutron activation analysis (NAA). The results showed that the crystallographic structure of the clinoptilolite did not change during thermal and chemical reduction treatments of Ag + to obtain the nanoparticles of Ag ο . The bactericide activity of the silver modified zeolitic materials (with Ag + or nanoparticles of Ag ο ) was evaluated on Escherichia coli Atcc 8739, in both distilled water and well

  1. KF/Clinoptilolite: an efficient promoter for the synthesis of thioethers.

    Science.gov (United States)

    Salmanpour, Sadegh; Khalilzadeh, Mohammad A; Hosseini, Abolfazl

    2013-06-01

    Potassium fluoride impregnated on natural zeolite as a new solid base system effectively catalyzes the coupling of thiophenols with electron-deficient fluoro-, chloro- and bromo-arenes in DMSO. This versatile and efficient solid base has been demonstrated to afford the corresponding desired products in good to excellent yields. This procedure provides a convenient, efficient and practical method for the preparation of diaryl thioethers.

  2. Utilization of Zeolites in environmentally protection

    Energy Technology Data Exchange (ETDEWEB)

    Kallo, D. [Hungarian Academy of Sciences, Chemical Research Center, Institute of Chemistry, Budapest (Hungary)

    2000-07-01

    It has been attempted to present the most important fields of natural zeolite applications in environmental protection. Realized and approved utilizations were demonstrated inciting the reader to take these materials into consideration for solution of similar problems. The outlined properties can be used for other purposes not discussed in this review. They can be applied, e.g., in fish farming, transportation of living fishes when simultaneous ammonium and carbon dioxide removals is required: ammonium is exchanged for calcium present in the zeolite and CO{sub 2} is then precipitated in the form of CaCO{sub 3}; in treatment of diluted manure when undesired organics can be fixed and bactericide effects can be attained. Natural zeolites are used, therefore, as deodorant of litter of dogs or cats. Small amounts of metal cations, e.g., Cu{sup 2+}, Ag{sup +} or Zn{sup 2+}, introduced by ion exchange may disinfect contacting water. Due to water adsorption and desorption capability natural zeolite as construction materials exert some conditioning effect without any mechanical accessory. It seems likely the human ingenuity will continue to discover new applications in the future.

  3. Zeolite-catalyzed hydrogenation of carbon dioxide and ethene.

    Science.gov (United States)

    Chan, Bun; Radom, Leo

    2008-07-30

    Ab initio molecular orbital theory and density functional theory calculations have been used to study the three-stage zeolite-catalyzed hydrogenation of CO2 to methanol and the hydrogenation of C2H 4 to ethane, with the aim of designing an effective zeolite catalyst for these reactions. Both Brønsted acid (XH) and alkali metal (XM) sites in model zeolites (-X-Al-XH- or -X-Al-XM-) have been examined. It is found that appropriately designed zeolites can provide excellent catalysis for these reactions, particularly for the hydrogenation of CO2, HCO2H and CH2O, with uncatalyzed barriers of more than 300 kJ mol(-1) being reduced to as little as 17 kJ mol(-1) (in the case of CH2O). The reaction barrier depends on the acidity of the XH moiety or the nature of the metal cation M in the XM moiety, and the basicity of the adjacent X group in the catalyst. For a catalyst based on alkali metal zeolites (XM), the catalytic activity is relatively insensitive to the nature of X in the XM group. As a result, the catalytic activity for these types of zeolites increases as X becomes more basic. We propose that alkali metal zeolites with Ge and N incorporated into the framework could be very effective catalysts for hydrogenation processes.

  4. Preparation of functionalized zeolitic frameworks

    Science.gov (United States)

    Yaghi, Omar M; Hayashi, Hideki; Banerjee, Rahul; Park, Kyo Sung; Wang, Bo; Cote, Adrien P

    2012-11-20

    The disclosure provides zeolitic frameworks for gas separation, gas storage, catalysis and sensors. More particularly the disclosure provides zeolitic frameworks (ZIFs). The ZIF of the disclosure comprises any number of transition metals or a homogenous transition metal composition.

  5. Preparation of functionalized zeolitic frameworks

    Science.gov (United States)

    Yaghi, Omar M; Furukawa, Hiroyasu; Wang, Bo

    2013-07-09

    The disclosure provides zeolitic frameworks for gas separation, gas storage, catalysis and sensors. More particularly the disclosure provides zeolitic frameworks (ZIFs). The ZIF of the disclosure comprises any number of transition metals or a homogenous transition metal composition.

  6. Rapid synthesis of beta zeolites

    Science.gov (United States)

    Fan, Wei; Chang, Chun -Chih; Dornath, Paul; Wang, Zhuopeng

    2015-08-18

    The invention provides methods for rapidly synthesizing heteroatom containing zeolites including Sn-Beta, Si-Beta, Ti-Beta, Zr-Beta and Fe-Beta. The methods for synthesizing heteroatom zeolites include using well-crystalline zeolite crystals as seeds and using a fluoride-free, caustic medium in a seeded dry-gel conversion method. The Beta zeolite catalysts made by the methods of the invention catalyze both isomerization and dehydration reactions.

  7. Investigation of the elution by seawater of caesium and strontium from loaded clinoptilolite

    International Nuclear Information System (INIS)

    Harder, B.R.; Mitchell, I.H.; Smyth, M.J.

    1985-07-01

    Simple investigations of the elution of caesium and strontium from loaded clinoptilolite are described. The clinoptilolite was loaded to levels expected in the British Nuclear Fuels plc SIXEP plant and contacted with seawater at approx. 15 C. (The elution time was measured until about 99% of the caesium and strontium had been eluted.) It was found that 99% of the caesium was eluted in 35 hours but the strontium (with more variable results) took at least 400 hours for 99% elution. (author)

  8. Distribution of metal and adsorbed guest species in zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Chmelka, B.F.

    1989-12-01

    Because of their high internal surface areas and molecular-size cavity dimensions, zeolites are used widely as catalysts, shape- selective supports, or adsorbents in a variety of important chemical processes. For metal-catalyzed reactions, active metal species must be dispersed to sites within the zeolite pores that are accessible to diffusing reactant molecules. The distribution of the metal, together with transport and adsorption of reactant molecules in zeolite powders, are crucial to ultimate catalyst performance. The nature of the metal or adsorbed guest distribution is known, however, to be dramatically dependent upon preparatory conditions. Our objective is to understand, at the molecular level, how preparatory treatments influence the distribution of guest species in zeolites, in order that macroscopic adsorption and reaction properties of these materials may be better understood. The sensitivity of xenon to its adsorption environment makes {sup 129}Xe NMR spectroscopy an important diagnostic probe of metal clustering and adsorbate distribution processes in zeolites. The utility of {sup 129}Xe NMR depends on the mobility of the xenon atoms within the zeolite-guest system, together with the length scale of the sample heterogeneity being studied. In large pore zeolites containing dispersed guest species, such as Pt--NaY, {sup 129}Xe NMR is insensitive to fine structural details at room temperature.

  9. Distribution of metal and adsorbed guest species in zeolites

    International Nuclear Information System (INIS)

    Chmelka, B.F.

    1989-12-01

    Because of their high internal surface areas and molecular-size cavity dimensions, zeolites are used widely as catalysts, shape- selective supports, or adsorbents in a variety of important chemical processes. For metal-catalyzed reactions, active metal species must be dispersed to sites within the zeolite pores that are accessible to diffusing reactant molecules. The distribution of the metal, together with transport and adsorption of reactant molecules in zeolite powders, are crucial to ultimate catalyst performance. The nature of the metal or adsorbed guest distribution is known, however, to be dramatically dependent upon preparatory conditions. Our objective is to understand, at the molecular level, how preparatory treatments influence the distribution of guest species in zeolites, in order that macroscopic adsorption and reaction properties of these materials may be better understood. The sensitivity of xenon to its adsorption environment makes 129 Xe NMR spectroscopy an important diagnostic probe of metal clustering and adsorbate distribution processes in zeolites. The utility of 129 Xe NMR depends on the mobility of the xenon atoms within the zeolite-guest system, together with the length scale of the sample heterogeneity being studied. In large pore zeolites containing dispersed guest species, such as Pt--NaY, 129 Xe NMR is insensitive to fine structural details at room temperature

  10. Zeolites and clays behavior in presence of radioactive solutions

    International Nuclear Information System (INIS)

    Carrera Garcia, L.M.

    1991-01-01

    Natural aluminosilicates have found application as selective ion exchangers for radioactive cations, present in liquid wastes arising from nuclear facilities. Among severals cations and complex mixtures of them, Co is a common constituent of liquid radioactive wastes. Two types of zeolites (Y zeolite, and natural mexican erionite), and two types of clays (natural bentonite, and Al-expanded bentonite (Al-B) were used. Previous to the experiments, the zeolites and the natural bentonite were stabilized to their respective Na + form using 5N NaCl solution. 2Na + → 60 Co 2+ ion exchange kinetics in zeolites and clays was followed by gamma spectrometry using a NaCl-Co(NO 3 ) 2 isonormal solution (0.1N) labeled with 60 Co-Co(NO 3 ) 2 (100 μ Ci). Before and after experiments, the structural changes in the cristallinity of aluminosilicates were determined by X-ray diffraction. XRD analyzes show that the cristallinity of the aluminosilicates was not affected by ion exchange. After Co exchange the cell parameters were determined in all samples. The efficiency of zeolites, natual clays and expanded clays to remove cobalt ions from solutions depends on the ion echange capacity of the material. Results for long contacts time, 18 days, show that Co is more effectively removed by Y zeolite ( 4.07 wt %), followed by erionite (3.09 wt %), then bentonite ( 2.36 wt %) and finally expanded bentonite ( 0.70 wt %). In Y zeolite an unusual fast soportion uptake of 4.51 % wt Co was observed followed by a desorption process to 4.07 %. This effect is due to the different hydration degree of zeolites during the contact time between the zeolite and the 60 Co solution. In erionite the exchange is lower than in Y-zeolite, frist because the Si/Al ratio is higher for erionite than for Y-zeolite and second because K ions in erionite cannot be exchanged during the stabilization of erionite in 5N NaCl solution. The low exchange in expanded bentonite was expected because its cation exchange

  11. Selective synthesis of FAU-type zeolites

    Science.gov (United States)

    Garcia, Gustavo; Cabrera, Saúl; Hedlund, Jonas; Mouzon, Johanne

    2018-05-01

    In the present work, parameters influencing the selectivity of the synthesis of FAU-zeolites from diatomite were studied. The final products after varying synthesis time were characterized by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction and gas adsorption. It was found that high concentrations of NaCl could completely inhibit the formation of zeolite P, which otherwise usually forms as soon as maximum FAU crystallinity is reached. In the presence of NaCl, the FAU crystals were stable for extended time after completed crystallization of FAU before formation of sodalite. It was also found that addition of NaCl barely changed the crystallization kinetics of FAU zeolite and only reduced the final FAU particle size and SiO2/Al2O3 ratio slightly. Other salts containing either Na or Cl were also investigated. Our results suggest that there is a synergistic effect between Na+ and Cl-. This is attributed to the formation of (Na4Cl)3+ clusters that stabilize the sodalite cages. This new finding may be used to increase the selectivity of syntheses leading to FAU-zeolites and avoid the formation of undesirable by-products, especially if impure natural sources of aluminosilica are used.

  12. Fly ash from a Mexican mineral coal. II. Source of W zeolite and its effectiveness in arsenic (V) adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Medina, Adriana [CINVESTAV IPN-Unidad Saltillo, Carretera Saltillo-Monterrey Km 13.5, C.P. 25900, Ramos Arizpe, Coahuila (Mexico); Gamero, Procoro, E-mail: pgamerom@hotmail.com [CINVESTAV IPN-Unidad Saltillo, Carretera Saltillo-Monterrey Km 13.5, C.P. 25900, Ramos Arizpe, Coahuila (Mexico); Almanza, Jose Manuel [CINVESTAV IPN-Unidad Saltillo, Carretera Saltillo-Monterrey Km 13.5, C.P. 25900, Ramos Arizpe, Coahuila (Mexico); Vargas, Alfredo; Montoya, Ascencion [Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152, G.A. Madero, C.P. 07730, Distrito Federal (Mexico); Vargas, Gregorio [CINVESTAV IPN-Unidad Saltillo, Carretera Saltillo-Monterrey Km 13.5, C.P. 25900, Ramos Arizpe, Coahuila (Mexico); Izquierdo, Maria [Instituto de Ciencias de la Tierra ' Jaume Almera' , CSIC, C/Luis Sole Sabaris, s/n 08028 Barcelona (Spain)

    2010-09-15

    Coal-fired plants in Coahuila (Mexico) produce highly reactive fly ash (MFA), which is used in a one-step process as a raw material in producing zeolite. We explored two routes in the synthesis of zeolite: (a) direct MFA zeolitization, which resulted in the formation of W zeolite with KOH and analcime with NaOH and (b) a MFA fusion route, which resulted in the formation of zeolite W or chabazite with KOH and zeolite X or P with NaOH. No residual crystalline phases were present. When LiOH was employed, ABW zeolite with quartz and mullite were obtained. For both zeolitization routes, the nature of the alkali (KOH, NaOH, LiOH), the alkali/MFA ratio (0.23-1.46), and the crystallization temperature and time (90-175 {sup o}C; 8-24 h) were evaluated. Additionally, the effect of temperature and time on MFA fusion was studied. W zeolite was obtained by both zeolitization methods. The direct route is preferred because it is a straightforward method using soft reaction conditions that results in a high yield of low cost zeolites with large crystal agglomerates. It was demonstrated that aluminum modified W zeolite has the ability to remove 99% of the arsenic (V) from an aqueous solution of Na{sub 2}HAsO{sub 4}.7H{sub 2}O originally containing 740 ppb.

  13. Inclusion of Yucca schidigera and zeolite in dog feed: influence on mineral excretion

    Directory of Open Access Journals (Sweden)

    J.P.F. Santos

    2013-06-01

    Full Text Available This study aimed to evaluate the effects of adding Yucca schidigera and zeolite (Clinoptilolite to feed (super premium and standard for adult dogs on the apparent indigestibility coefficient of minerals. In the first assessment, 21 dogs were used, with average weight of 12.5kg±1.46 in seven treatments in two periods (super premium diet referred to as control and control with the addition of 125, 250, 375ppm Yucca schidigera and 0.5%, 0.75% and 1.0% zeolite. The second assessment was conducted with standard feed, using 21 experimental plots distributed in three treatments (standard diet referred to as control and control with the addition of 375ppm of Yucca schidigera and 1.0% zeolite. The additives did not affect the acceptability of feed and fecal characteristics in both assessments (P>0.05. With the exception of calcium, no minerals were affected by the inclusion of additives (P>0.05 in the experiment with super premium feed. In the assessment with standard feed, calcium as phosphorus and magnesium presented decreased excretion (P<0.05 with the inclusion of additives. It is possible to conclude that the inclusion of additives in the tested concentrations may interfere with the excretion of some minerals in the diet.

  14. Impacts of zeolite nanoparticles on substrate properties of thin film nanocomposite membranes for engineered osmosis

    Science.gov (United States)

    Salehi, Tahereh Mombeini; Peyravi, Majid; Jahanshahi, Mohsen; Lau, Woei-Jye; Rad, Ali Shokuhi

    2018-04-01

    In this work, microporous substrates modified by zeolite nanoparticles were prepared and used for composite membrane making with the aim of reducing internal concentration polarization (ICP) effect of membranes during engineered osmosis applications. Nanocomposite substrates were fabricated via phase inversion technique by embedding nanostructured zeolite (clinoptilolite) in the range of 0-0.6 wt% into matrix of polyethersulfone (PES) substrate. Of all the substrates prepared, the PES0.4 substrate (with 0.4 wt% zeolite) exhibited unique characteristics, i.e., increased surface porosity, lower structural parameter ( S) (from 0.78 to 0.48 mm), and enhanced water flux. The thin film nanocomposite (TFN) membrane made of this optimized substrate was also reported to exhibit higher water flux compared to the control composite membrane during forward osmosis (FO) and pressure-retarded osmosis (PRO) test, without compromising reverse solute flux. The water flux of such TFN membrane was 43% higher than the control TFC membrane (1.93 L/m2 h bar) with salt rejection recorded at 94.7%. An increment in water flux is ascribed to the reduction in structural parameter, leading to reduced ICP effect.

  15. INVESTIGATION OF CLINOPTILOLITE MODIFIED WITH IONS OF HYDROGEN, PALLADIUM(II, AND COPPER(II BY IR AND DIFFUSE REFLECTANCE SPECTRAL METHODS

    Directory of Open Access Journals (Sweden)

    T. L. Rakytskaya

    2016-07-01

    Full Text Available Changes appeared in IR and diffuse reflectance UV-vis spectra of clinoptilolite as a result of its modification by boiling in nitric acid solutions (0.25-3 M and anchoring active components on it were analyzed. As was shown by IR spectroscopy, the increase in acid concentration caused a high-frequency shift of the band attributed to asymmetric stretching vibrations of the Si-O-Al fragment due to the clinoptilolite dealumination. The values of this shift were not changed after active components anchoring on the acid modified clinoptilolite samples.  The band of deformation vibrations of OH groups in water molecules (at 1633 cm-1 for natural clinoptilolite was weakly affected (a slight high-frequency shift by the acid concentration increase and remained practically unaffected by anchoring palladium and copper ions. However,  the effect of Pd(II and Cu(II anchoring on IR spectra could be observed through a low-frequency shift of the band characterizing stretching vibration νОН of OH groups in water molecules indicating some disturbance of hydrogen bonds in H2O molecules and a change in their energy. The UV region of diffuse reflectance UV-vis spectra of all anchored catalyst samples showed the appearance of new intense bands at 224-226, 279-284, and 327-334 nm which were absent Pd-Cu complexes which attendance is necessary for catalytic low-temperature oxidation of carbon monoxide with air oxygen. It should be noted that a new band appeared at 351-363 nm would be assigned to individual Pd(II indicating that some portion of palladium(II ions did not participate in the formation of the catalytically active bimetallic Pd-Cu complexes. The presence of individual palladium(II was confirmed by the fact that only the bends characteristic of square planar palladium(II complexes were observed in the palladium(II absorbing region in the visible part of diffuse reflectance UV-vis spectra. Additionaly, theses spectra also contained the bends corresponding

  16. Geochemical modelling for predicting the long-term performance of zeolite-PRB to treat lead contaminated groundwater

    Science.gov (United States)

    Obiri-Nyarko, Franklin; Kwiatkowska-Malina, Jolanta; Malina, Grzegorz; Kasela, Tomasz

    2015-06-01

    The feasibility of using geochemical modelling to predict the performance of a zeolite-permeable reactive barrier (PRB) for treating lead (Pb2 +) contaminated water was investigated in this study. A short-term laboratory column experiment was first performed with the zeolite (clinoptilolite) until the elution of 50 PV (1 PV = ca. 283 mL). Geochemical simulations of the one-dimensional transport of the Pb2+, considering removal processes including: ion-exchange, adsorption and complexation; the concomitant release of exchangeable cations (Ca2 +, Mg2 +, Na+, and K+) and the changes in pH were subsequently performed using the geochemical model PHREEQC. The results showed a reasonable agreement between the experimental results and the numerical simulations, with the exception of Ca2 + for which a great discrepancy was observed. The model also indicated the formation of secondary mineral precipitates such as goethite and hematite throughout the experiment, of which the effect on the hydraulic conductivity was found to be negligible. The results were further used to extrapolate the long-term performance of the zeolite. We found the capacity would be completely exhausted at PV = 250 (ca. 3 days). The study, thus, generally demonstrates the applicability of PHREEQC to predict the short and long-term performance of zeolite-PRBs. Therefore, it can be used to assist in the design and for management purposes of such barriers.

  17. Effects of Zeolite (Clinoptelolite on Performance Characteristics of

    Directory of Open Access Journals (Sweden)

    A Hassan Abadim

    2011-12-01

    Full Text Available A 70-days experiment was conducted to investigate the effects of natural zeolite (clinoptelolite on the performance of commercial laying hens. 288 Hy-Line W36 strain laying hens (50 weeks old were allotted to 6 dietary treatments including basal diet as control and basal diet supplemented with 1, 2, 3, 4 and 5% zeolite that were fed ad -libitum throughout the experiment. Experimental diets for the 6 treatments were prepared to be iso-caloric and iso-nitrogenous. A completely randomized design with six treatments, eight replicates of six birds per replicate was used at this experiment. Daily feed intake (DFI, feed conversion ratio (FCR, egg production, egg weight, egg white quality, eggshell quality (thickness and percentage and body weight changes were measured during the experiment. Results of this experiment showed that DFI, FCR, egg production and egg abnormality were not significantly (P>0.05 affected by zeolite supplementation. Zeolite supplementation significantly increased egg weight, eggshell thickness and live body weight gain of the hens. Dietary zeolite significantly decreased haugh unit of the eggs. In conclusion, natural zeolite significantly improved egg weight and eggshell quality, decreased haugh unit and live weight gain, and had no significant effects on other parameters.

  18. Obtaining of supports macro and micro nutrients with base in zeolites mexicans

    International Nuclear Information System (INIS)

    Cordova H, A.; Islas M, M.; Bascunan S, C.; Martines G, M.; Nikolaev N, S.

    2001-01-01

    Study the effect of application of the zeolites modified by the ionico interchange with fertilizers (NPK), N-p in the production of tomatos. The cultive of tomatos was made in lands of the Benemerita Autonoma Universidad de Puebla, Mexico, taking equal quadrants with the following ground treatments: 1) zeolite interchanged with fertilizers, 2) zeolite interchanged with a solution that contained only N-p, 3) natural zeolite without ionica modification and a quadrant witness represented by the ground without treatment. The collected data show an increase in the harvest of tomatos, as well as the retention of the decomposition of the harvested tomatos. In addition, it determinated that the optimal concentrations in the case of the zeolite dealt with 3% of fertilizer NPK are: 0,91% of potassium and 0.61% of nitrogen. These results allow to suggest the use of zeolites modified by ionico interchange in agriculture to elevate the level of the harvests of the tomato [es

  19. Reduction of radiocaesium transfer to broiler chicken meat by a clinoptilolite modified with hexacyanoferrate

    International Nuclear Information System (INIS)

    Poeschl, M.; Balas, J.

    1999-01-01

    The effect of RADEKONT (a natural clinoptilolite modified by hexacyanoferrate) on 137 Cs uptake into meat was tested in experiments with broiler chickens. Three experiments determined the influence of RADEKONT on radiocaesium transfer after single or repeated applications of artificially contaminated feed mixture and one experiment investigated the effect of RADEKONT when feeding a mixture containing wheat contaminated by the Chernobyl fallout. Independent of the effect of RADEKONT, the uptake of radiocaesium was faster in leg meat than in breast meat. Reduction factors ( 137 Cs transfer without the RADEKONT additive compared with those observed after supplementation of the additive into the feed mixture) of 1.1-1.3 and 1.2-2.3, respectively, were achieved after single and repeated administrations of artificially contaminated feed. No significant differences in reduction between breast and leg meat were observed. RADEKONT was more effective when the chickens were fed with Chernobyl-contaminated wheat (reduction factors of up to 3.7) than an artificial 137 Cs source. RADEKONT as a supplement during the decontamination period decreased the biological half-life of 137 C to less than 1 day. The timing of the application of RADEKONT might be important in determining its effectiveness, especially in young, rapidly growing chickens. (orig.)

  20. Effects of earthworm casts and zeolite on the two-stage composting of green waste

    International Nuclear Information System (INIS)

    Zhang, Lu; Sun, Xiangyang

    2015-01-01

    Highlights: • Earthworm casts (EWCs) and clinoptilolite (CL) were used in green waste composting. • Addition of EWCs + CL improved physico-chemical and microbiological properties. • Addition of EWCs + CL extended the duration of thermophilic periods during composting. • Addition of EWCs + CL enhanced humification, cellulose degradation, and nutrients. • Combined addition of 0.30% EWCs + 25% CL reduced composting time to 21 days. - Abstract: Because it helps protect the environment and encourages economic development, composting has become a viable method for organic waste disposal. The objective of this study was to investigate the effects of earthworm casts (EWCs) (at 0.0%, 0.30%, and 0.60%) and zeolite (clinoptilolite, CL) (at 0%, 15%, and 25%) on the two-stage composting of green waste. The combination of EWCs and CL improved the conditions of the composting process and the quality of the compost products in terms of the thermophilic phase, humification, nitrification, microbial numbers and enzyme activities, the degradation of cellulose and hemicellulose, and physico-chemical characteristics and nutrient contents of final composts. The compost matured in only 21 days with the optimized two-stage composting method rather than in the 90–270 days required for traditional composting. The optimal two-stage composting and the best quality compost were obtained with 0.30% EWCs and 25% CL

  1. Does the combination of biochar and clinoptilolite enhance nutrient recovery from the liquid fraction of biogas digestate?

    NARCIS (Netherlands)

    Kocatürk-Schumacher, Nazlı Pelin; Zwart, Kor; Bruun, Sander; Brussaard, Lijbert; Jensen, Lars Stoumann

    2017-01-01

    Concentrating nutrients on biochar and clinoptilolite and subsequently using the nutrient-enriched sorbents as a fertiliser could be an alternative way to manage nutrients in digestate. In this study, we investigated the use of biochar and clinoptilolite columns in removing ammonium, potassium,

  2. Ammonia-nitrogen and phosphates sorption from simulated reclaimed waters by modified clinoptilolite.

    Science.gov (United States)

    Huo, Hanxin; Lin, Hai; Dong, Yingbo; Cheng, Huang; Wang, Han; Cao, Lixia

    2012-08-30

    This paper presents the investigation of the ammonia-nitrogen and phosphates sorption from simulated reclaimed wastewater by modified clinoptilolite. The results showed that the modified clinoptilolite has a high sorption efficiency and removal performance. The ammonia-nitrogen and phosphates removal rate of the modified clinoptilolite reached to 98.46% and 99.80%, respectively. The surface of modified clinoptilolite became loose and some pores appeared, which enlarged the specific surface area; the contents of Na and Fe increased, and the contents of Ca and Mg decreased. The modified clinoptilolite possesses rapid sorption and slow balance characteristics and ammonia-nitrogen and phosphates sorption is more consistent with the Langmuir isotherm model. The adsorption kinetics of ammonia-nitrogen and phosphates follows the Elovich adsorption dynamics equation, which describes the sorption of ammonia-nitrogen and phosphates in aqueous solution as mainly a chemical sorption. Results from the thermodynamics experiment involving ammonia-nitrogen and phosphates sorption reveal that the process is a spontaneous and endothermic process, and is mainly driven by entropy effect. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Evaluation of clinoptilolite for removal of ammoniacal nitrogen produced in aquaculture by Neutron activation analysis and UV-VIS spectrophotometry

    International Nuclear Information System (INIS)

    Bibiano C, L.; Iturbe G, J.L.; Lopez M, B.E.; Martinez M, V.

    1997-01-01

    In fish culture system, ammonia is excreted in the water as a metabolic by-product. In this work, sorption properties of clinoptilolite were determined and it was applied in culture of the rainbow trout Oncorhynchus mykiss for the removal of the ammoniacal nitrogen. The original clinoptilolite was treated with 1N NaCl solution from 24 to 192 h, for exchange NH 4 ions produced in fish culture. The content of Na in the clinoptilolite was determined by neutron activation analysis. The ammonium ion content in the exchange was analysed by UV-VIS spectrophotometry. Maximum uptake of sodium was reached between 24 and 48 hours at neutral pH with granules of the clinoptilolite from 14 to 24 mesh size. The adsorption capacity was from 3.28 to 6.8 mg of ammonium per gram of clinoptilolite. (Author)

  4. Biodiesel synthesis via transesterification of lipid Chlorophyta cultivated in walne rich carbon medium using KOH/Zeolite catalyst

    Science.gov (United States)

    Dianursanti, Hayati, Siti Zahrotul; Putri, Dwini Normayulisa

    2017-11-01

    Microalgae from the Chlorophyta division such as Nannochloropsis oculata and Chlorella vulgaris are highly potential to be developed as biodiesel feedstocks because they have a high oil content up to 58%. Biodiesel is produced by transesterification of triglycerides and alcohols with the aid of homogeneous catalysts such as KOH. However, the use of KOH catalysts produces soaps in the biodiesel synthesis. Heterogeneous catalysts are known to solve this problem. One of them is natural zeolite. Zeolite can be used as a catalyst and as a support catalyst. Loading KOH on the zeolite surface is expected to increase alkalinity in KOH/Zeolite catalysts so as to increase the activity of KOH/Zeolite catalyst in transesterification of triglyceride with methanol. In this experimental lipid of microalgae will be used for produced biodiesel via transesterification reaction with methanol and KOH/Zeolite as a catalyst heterogeneous at 60 °C for 3h and utilized catalyst modificated KOH/Zeolite with variation 0.5 M, 1 M and 1.5 M KOH. The modified zeolite was then analyzed by XRF, XRD and BET. The result showed that the yield of biodiesel from lipid N.oculata was 81,09% by 0.5KOH/Zeolite catalyst, 86,53% by 1KOH/Zeolite catalyst, 1,5KOH/Zeolite and 88,13% by 1.5KOH/Zeolit, while the biodiesel produced from lipid C.vulgaris was 59.29% by 0.5KOH/Zeolite, 82.27% by 1KOH/Zeolite and 83.72% by 1.5KOH/Zeolite.

  5. Investigation of zeolites by solid state quadrapole NMR

    International Nuclear Information System (INIS)

    Janssen, R.

    1990-01-01

    The subject of this thesis is the NMR investigation of zeolites. The nature and properties of zeolites are discussed. Some of the basic priniples of NMR techniques on quadrupole nuclei are presented. A special technique, namely a two-dimensional nutation experiment is discussed in detail. The theory of the nutation experiment for quadrupole spin species with spin quantum number 3/2 as well as 5/2 is presented. For both spin spcies the theoretical spectra are compared with experimental results. It is also shown that the nutation expeirment can be performed with several pulse schemes. It is shown how phase-sensitive pure-absorption nutation spectra can be obtained and an NMR-probe is presented that is capable of performing NMR experiments at high (up to 500 degree C) temperatures. The two-dimensional nutation NMR technique has been applied to sodium cations in zeolite NaA. For this purpose a numbre of zeolite samples were prepared that contained different amounts of water. With the aid of nutation NMR the hydration of the zeolite can be studied and conclusions can be drawn about the symmetry of the surrounding of the sodium cations. With the aid of an extension of the nutation NMR experiment: Rotary Echo Nutation NMR, it is shown that in zeolite NaA, in various stages of hydration, the sodium cations or water molecules are mobile. Proof is given by means of high-temperature 23 Na-NMR that dehydrates zeolite NaA undergoes a phase transition at ca. 120 degree C. In a high-temperature NMR investigation of zeolite ZSM-5 it is shown that the sodium ions start to execute motions when the temperature is increased. (author). 198 refs.; 72 figs.; 6 tabs

  6. Physico-chemical characteristics and environmental exploitation of clinoptilolite Nizny Hrabovec

    International Nuclear Information System (INIS)

    Chmielewska, E.

    1999-01-01

    The clinoptilolite tuff used in this study, active mineral content of which was measured according to standardized techniques (e.g. X-ray diffraction, ion-exchange, water-vapor desorption) was 60% enriched. Physico-chemical characteristics considered from point of view as water treatment material and compared to siliceous sand and active coal as well as to some foreign clinoptilolite samples, e.g. mineralogical and chemical composition, thermic, alkali- and acid resistance, specific gravity, surface area, porosity, shipping weight, mechanical attrition and powdering survey, adsorption capacities of clinoptilolite towards Cs, Ba, Co, Fe, I, Ag, Zn and ammonium, hydration-dehydration behaviours and selectivity properties from among a major number of cations, have been investigated. Some pilot plant experiences of drinking water treatment with enhanced ammonium concentration on the field facility close to Bratislava and of tannery waste water treatment at Moravian plant using inland clinoptilolite will be presented. Mass-balance recycling loop for regeneration constituents recovery in tannery processing industry (ammonia and chromium) has been proposed and applied during pilot studies (capacity of installations ∼ 1 m 3 /hr). Iron and ammonium removal by addition of powdered clinoptilolite tuff in chemical coagulation processes for specific polluted surface water purification has been proven, respectively. Economic evaluation of ion-exchange technology by means of clinoptilolite with chemical regeneration and regeneration recovery by air-stripping method and of biological nitrification-denitrification for model hydraulic loading rate 6000 m 3 / day was calculated as well as the operating cost of both technologies were compared and will be documented. (author)

  7. Synthesis and characterization of zeolite material from coal ashes modified by surfactant; Sintese e caracterizacao de material zeolitico de cinzas de carvao modificado por surfactante

    Energy Technology Data Exchange (ETDEWEB)

    Fungaro, D.A., E-mail: dfungaro@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (CQMA/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Quimica e Meio Ambiente; Borrely, S.I. [Instituto de Pesquisas Energeticas e Nucleares (CTR/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Tecnologia das Radiacoes

    2010-07-01

    Coal ash was used as starting material for zeolite synthesis by means of hydrothermal treatment. The surfactant-modified zeolite (SMZ) was prepared by adsorbing the cationic surfactant hexadecyltrimethylammonium bromide (HDTMA-Br) on the external surface of the zeolite from coal ash. The zeolite structure stability was monitored during the characterization of the materials by FTIR, XDR and SEM. The structural parameters of surfactant-modified zeolite are very close to that of corresponding non-modified zeolite which indicates that the crystalline nature of the zeolite remained intact after required chemical treatment with HDTMA-Br molecules and heating treatment for drying. The most intense peaks in the FTIR spectrum of HDTMA-Br were observed in SMZ spectrum confirming adsorption of surfactant on zeolites. (author)

  8. Remoção de metais pesados de efluentes aquosos pela zeólita natural escolecita - influência da temperatura e do pH na adsorção em sistemas monoelementares Heavy metals removal from wastewater by the natural zeolite scolecite - temperature and pH influence in single-metal solutions

    Directory of Open Access Journals (Sweden)

    Ricardo Sarti Jimenez

    2004-10-01

    Full Text Available Cation exchange capabilities of a Brazilian natural zeolite, identified as scolecite, were evaluated for application in wastewater control. We investigated the process of sorption of chromium(III, nickel(II, cadmium(II and manganese(II in synthetic aqueous effluents, including adsorption isotherms of single-metal solutions. The natural zeolite showed the ability to take up the tested heavy metals in the order Cr(III > Cd(II > Ni(II > Mn(II, and this could be related to the valence and the hydration radius of the metal cations. The influence of temperature (25, 40 and 60 ºC and initial pH value (from 4 to 6 was also evaluated. It was found that the adsorption increased substantially when the temperature was raised to 60 ºC and that maximum adsorption capacity was observed at pH 6. These results demonstrate that scolecite can be used for removal of heavy metals from aqueous effluents, under optimized conditions.

  9. Surfactant-modified zeolites as permeable barriers to organic and inorganic groundwater contaminants

    International Nuclear Information System (INIS)

    Bowman, R.S.; Sullivan, E.J.

    1995-01-01

    We have shown in laboratory experiments that natural zeolites treated with hexadecyltrimethylammonium (HDTMA) are effective sorbents for nonpolar organics, inorganic cations, and inorganic anions. Due to their low cost (∼$0.75/kg) and granular nature, HDTMA-zeolites appear ideal candidates for reactive, permeable subsurface barriers. The HDTMA-zeolites are stable over a wide range of pH (3-13), ionic strength (1 M Cs + or Ca 2+ ), and in organic solvents. Surfactant-modified zeolites sorb nonpolar organics (benzene, toluene, xylene, chlorinated aliphatics) via a partitioning mechanism, inorganic cations (Pb 2+ ) via ion exchange and surface complexation, and inorganic anions (CrO 4 2- , SeO 4 2- , SO 4 2- ) via surface precipitation.The goal of this work is to demonstrate the use of surfactant-modified zeolite as a permeable barrier to ground water contaminants

  10. Mesoporous zeolites obtained by desilication

    NARCIS (Netherlands)

    Groen, J.C.

    2007-01-01

    Zeolites are crystalline microporous materials consisting of silicon, aluminium and oxygen atoms. A unique combination of properties such as high surface area, high (hydro)thermal stability, and strong acidity, makes that zeolites are frequently used as catalysts in various (petro)chemical

  11. Adsorpsi Ion Logam Tembaga Menggunakan Nano Zeolit Alam yang Diaktivasi

    OpenAIRE

    Yulianis Yulianis; Mahidin Mahidin; Syaifullah Muhammad

    2017-01-01

    This study was aimed to find out the ability of natural zeolite coming from Blang Pidie, South West Aceh District, Aceh Province, Indonesia, which was applied as an adsorbent to adsorp heavy metal copper (Cu²⁺) ions in aqueous solution. This research was conducted to enhance the performance of natural zeolite by downsizing it to nano particles, then activated physically and chemically using 0.05 M HCl, then calcined at temperature 350°C for 2 hours. Test of Cu²⁺ metal ion adsorption to nano n...

  12. Does the combination of biochar and clinoptilolite enhance nutrient recovery from the liquid fraction of biogas digestate?

    Science.gov (United States)

    Kocatürk-Schumacher, Nazlı Pelin; Zwart, Kor; Bruun, Sander; Brussaard, Lijbert; Jensen, Lars Stoumann

    2017-05-01

    Concentrating nutrients on biochar and clinoptilolite and subsequently using the nutrient-enriched sorbents as a fertiliser could be an alternative way to manage nutrients in digestate. In this study, we investigated the use of biochar and clinoptilolite columns in removing ammonium, potassium, orthophosphate and dissolved organic carbon (DOC) from the liquid fraction of digestate. Our objectives were to investigate the effect of the initial loading ratio between liquid and biochar on nutrient removal, and to investigate the effect of combining biochar with clinoptilolite on nutrient and DOC removal efficiency. Increasing the initial loading ratios increased nutrient concentrations on biochar to 8.61 mg NH 4 -N g -1 , 1.95 mg PO 4 -P g -1 and 13.01 mg DOC g -1 , but resulted in decreasing removal efficiencies. The combination of biochar and clinoptilolite resulted in improved ammonium, potassium and DOC removal efficiencies compared to biochar alone, but did not significantly change PO 4 -P removal efficiencies. Removal efficiencies with combined sorbents were up to 67% for ammonium, 58% for DOC and 58% for potassium. Clinoptilolite showed higher removal efficiencies compared to biochar alone, and combining clinoptilolite with biochar improved only total P removal efficiency. Concentrating nutrients with clinoptilolite and biochar may be an option when both sorbents are available at low cost.

  13. Method for producing zeolites and zeotypes

    DEFF Research Database (Denmark)

    2015-01-01

    The invention relates to a method for producing zeolite, zeolite-like or zeotype particles comprising the steps of: 1 ) Adding one or more metal precursors to a silica or alumina source; 2) Reducing the one or more metal precursors to form metal nanoparticles on the surface of the silica or alumina...... source; 3) Passing a gaseous hydrocarbon, alkyl alcohol or alkyl ether over the silica or alumina supported metal nanoparticle to form a carbon template coated zeolite, zeolite-like or zeotype precursor composition; 4a) Adding a structure directing agent to the carbon template coated zeolite, zeolite......-like or zeotype precursor composition thereby creating a zeolite, zeolite-like or zeotype gel composition; 4b) Crystallising the zeolite, zeolite-like or zeotype gel composition by subjecting said composition to a hydrothermal treatment; 5) Removing the carbon template and structure directing agent and isolating...

  14. Method of producing zeolite encapsulated nanoparticles

    DEFF Research Database (Denmark)

    2015-01-01

    The invention therefore relates to a method for producing zeolite, zeolite-like or zeotype encapsulated metal nanoparticles, the method comprises the steps of: 1) Adding one or more metal precursors to a silica or alumina source; 2) Reducing the one or more metal precursors to form metal...... nanoparticles on the surface of the silica or alumina source; 3) Passing a gaseous hydrocarbon, alkyl alcohol or alkyl ether over the silica or alumina supported metal nanoparticles to form a carbon template coated zeolite, zeolite-like or zeotype precursor composition; 4a) Adding a structure directing agent...... to the carbon template coated zeolite, zeolite-like or zeotype precursor composition thereby creating a zeolite, zeolite-like or zeotype gel composition; 4b) Crystallising the zeolite, zeolite-like or zeotype gel composition by subjecting said composition to a hydrothermal treatment; 5) Removing the carbon...

  15. Removal of excess nutrients by Australian zeolite during anaerobic digestion of swine manure.

    Science.gov (United States)

    Wijesinghe, D Thushari N; Dassanayake, Kithsiri B; Scales, Peter; Sommer, Sven G; Chen, Deli

    2018-03-21

    The objective of this study was to investigate the feasibility of using natural and NaCl-treated Australian zeolites to simultaneously remove excess nutrients from anaerobically digested swine manure. Ion adsorption and desorption properties of Australian zeolite during the anaerobic digestion of swine manure were investigated. Two experiments were conducted: the first was an adsorption experiment with multi-component solutions that corresponded with the ionic composition of swine manure digestates. The second experiment determined the effects of zeolite dose rates during anaerobic digestion of swine manure on the removal of N, P and K from solution. Adsorption isotherms confirmed selectivity for K + over NH 4 + by Australian natural and sodium zeolites. Therefore, NH 4 + removal was considerably reduced when there was simultaneous K + uptake. Natural zeolite desorbed more Ca 2+ during K + and NH 4 + adsorption than sodium zeolite. The ion exchange reaction was independent of the presence of P. P removal was very dependent on the pH of the medium. Natural Australian zeolite was shown to be a potential sorbent for the removal of NH 4 + , K + and P during the anaerobic digestion of swine manure. However, the application of high concentrations of zeolite at higher pH values (> 7.5) might not be appropriate for anaerobic digestion, because zeolite desorbed more Ca 2+ ions into the solution at the higher doses of zeolite and then availability of P for microbial growth might be reduced as a result of PO 4 3- precipitation with Ca 2+ at the higher pH.

  16. INTERKALASI XILENOL ORANGE PADA ZEOLIT ALAM LAMPUNG SEBAGAI ELEKTRODA ZEOLIT TERMODIFIKASI

    Directory of Open Access Journals (Sweden)

    Fitriyah Fitriyah

    2016-07-01

    Full Text Available Zeolit terbagi menjadi zeolit alam dan zeolit sintesis, kapasitas adsorpsi zeolit alam umumnya lebih rendah daripada zeolit sintesis, sehingga untuk meningkatkan kapasitas adsorpsinya, karakter permukaan zeolit alam perlu diubah dengan melakukan proses modifikasi permukaan melalui berbagai metode, salah satunya dengan metode interkalasi. Tujuan penelitian ini yaitu menginterkalasi zat warna xilenol orange ke dalam zeolit alam Lampung dan mengaplikasikannya sebagai elektroda zeolit termodifikasi. Melalui proses interkalasi diharapkan dapat meningkatkan kegunaan dan nilai tambah dari zeolit. Data hasil penelitian menunjukkan bahwa xilenol orange (XO dapat diinterkalasikan ke dalam zeolit, hal ini dapat dilihat dari pita spektrum FTIR yang memiliki serapan pada bilangan gelombang 1383 cm-1, yaitu menunjukkan serapan dari S=O simetris dan asimetris pada gugus –SO3H,hal ini diduga karena XO memiliki gugus SO3 sehingga menyebabkan adanya serangan pada proton zeolit. Berdasarkan penelitian dapat disarikan bahwa xilanol orange dapat terinterkalasi pada zeolit alam Lampung dan dapat dimanfaatkan sebagai elektroda pendeteksi logam.

  17. Studi Hubungan Struktur Mikro dan Keaktifan Zeolit Alam Akibat Proses Pengasaman

    Directory of Open Access Journals (Sweden)

    Made Cuaca Vahindra Suriawan

    2012-11-01

    Full Text Available Natural zeolite is known as metal pollutant adsorbent in industrial waste treatment. As initial study for utilization ofnatural zeolite from Indonesia for metal pollutants adsorbent in liquid waste, then the physical properties should berecognized first. Activation is the first step in order to the natural zeolite able to adsorb the metal pollutants in the waste.One method to activate is by applying acid solution such as sulfuric acid (H2SO4 to activate the natural zeolite. The purposeof this research is to observe the change on microstructure of natural zeolite obtained from the mining at Tasikmalaya, WestJava, Indonesia due to chemical activated, to be compared to one without chemical activation. The variation of concentrationof H2SO4 namely: 2 4 , 6, 8, and 10 % , with 30 minutes soaking time , in a room temperatur. The microstructure then isobserved by using optical microscope following standard for ceramography. The change in microstructure then is analyzedand studied to be related with the ability of natural zeolite in adsorb the metal pollutant. The level activity of the zeolite canbe recognized by measuring its porosity.

  18. Zeolite and wollastonite synthesis from rice hull ash

    International Nuclear Information System (INIS)

    Fernandes, Alberto de Andrade

    2006-01-01

    Rice hull ash (RHA) is a industry scrap rich in amorphous silica. A simple and low-energy cost method for the extraction of this silica was researched. A low level of impurity and high reactivity material was produced, which is appropriate for the synthesis of zeolites and wollastonite (CaSiO 3 ). The synthetic zeolites has not similar structures in nature, and they have been more and more valued in the market due to their purity and efficiency in specific applications like ion exchange, molecular sieve and catalysis areas. High purity wollastonite has many applications in manufacturing and agriculture. The mineral wollastonite can be formed in nature in different ways; it is generally accepted two forming processes, both encompassing limestone metamorphism (heat and pressure). In this work, a new process for the synthesis of zeolites and wollastonite from RHA colloidal silica was developed. Moreover, the process is aimed at lower energy costs, fewer stages and fewer reactants consume. In this work, zeolite A used in detergent and zeolite ZSM-5, employed in the petrochemical industry due to its high selectivity in catalytic reactions and its high thermo and acid stability, were synthesized. The first step of the wollastonite synthesis was studied, with the purpose of obtaining calcium hydrosilicate. Eleven different hydrosilicates occur in the system Ca(OH) 2 -SiO 2 -H 2 O, in the second step it was annealed to form the wollastonite phase. (author)

  19. Encapsulation of Cs/Sr contaminated clinoptilolite in geopolymers produced from metakaolin

    Energy Technology Data Exchange (ETDEWEB)

    Kuenzel, C., E-mail: c.kuenzel08@imperial.ac.uk [Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW72AZ (United Kingdom); Centre for Advanced Structural Ceramics, Department of Materials, Imperial College London, South Kensington Campus, London SW72AZ (United Kingdom); Cisneros, J.F. [Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW72AZ (United Kingdom); Neville, T.P. [Centre for CO_2 Technology, Department of Chemical Engineering, University College London, Gower Street, London WC1E6JE (United Kingdom); Vandeperre, L.J. [Centre for Advanced Structural Ceramics, Department of Materials, Imperial College London, South Kensington Campus, London SW72AZ (United Kingdom); Simons, S.J.R.; Bensted, J. [Centre for CO_2 Technology, Department of Chemical Engineering, University College London, Gower Street, London WC1E6JE (United Kingdom); Cheeseman, C.R. [Department of Civil and Environmental Engineering, Imperial College London, South Kensington Campus, London SW72AZ (United Kingdom)

    2015-11-15

    The encapsulation of caesium (Cs) and strontium (Sr) contaminated clinoptilolite in Na and K based metakaolin geopolymers is reported. When Cs or Sr loaded clinoptilolite is mixed with a metakaolin geopolymer paste, the high pH of the activating solution and the high concentration of ions in solution cause ion exchange reactions and dissolution of clinoptilolite with release of Cs and Sr into the geopolymer matrix. The leaching of Cs and Sr from metakaolin-based geopolymer has therefore been investigated. It was found that Na-based geopolymers reduce leaching of Cs compared to K-based geopolymers and the results are in agreement with the hard and soft acids and bases (HSAB) theory. Cs ions are weak Lewis acids and aluminates are a weak Lewis base. During the formation of the geopolymer matrix Cs ions are preferentially bound to aluminate phases and replace Na in the geopolymer structure. Sr uptake by Na-geopolymers is limited to 0.4 mol Sr per mole of Al and any additional Sr is immobilised by the high pH which causes precipitation of Sr as low solubility hydroxide and carbonate phases. There was no evidence of any other phases being formed when Sr or Cs are added to metakaolin geopolymers. - Highlights: • Leaching. • Encapsulation of Cs and Sr. • Nuclear waste. • Clinoptilolite.

  20. The influence of pH on the adsorption of lead by Na-clinoptilolite ...

    African Journals Online (AJOL)

    The objectives of this study were, firstly, to establish the mechanism by which modified clinoptilolite (in Na form) adsorbs lead ions and, secondly, to assess the extent of influence of pH on the adsorption capacity. To this end, the experimental data have been fitted by adsorption isotherms, thermodynamic and kinetic models.

  1. The flexibility window in zeolites.

    Science.gov (United States)

    Sartbaeva, Asel; Wells, Stephen A; Treacy, M M J; Thorpe, M F

    2006-12-01

    Today synthetic zeolites are the most important catalysts in petrochemical refineries because of their high internal surface areas and molecular-sieving properties. There have been considerable efforts to synthesize new zeolites with specific pore geometries, to add to the 167 available at present. Millions of hypothetical structures have been generated on the basis of energy minimization, and there is an ongoing search for criteria capable of predicting new zeolite structures. Here we show, by geometric simulation, that all realizable zeolite framework structures show a flexibility window over a range of densities. We conjecture that this flexibility window is a necessary structural feature that enables zeolite synthesis, and therefore provides a valuable selection criterion when evaluating hypothetical zeolite framework structures as potential synthetic targets. We show that it is a general feature that experimental densities of silica zeolites lie at the low-density edge of this window--as the pores are driven to their maximum volume by Coulomb inflation. This is in contrast to most solids, which have the highest density consistent with the local chemical and geometrical constraints.

  2. Kinetics Modeling and Isotherms for Adsorption of Phosphate from Aqueous Solution by Modified Clinoptilolit

    Directory of Open Access Journals (Sweden)

    Mohammad Malakootian

    2012-01-01

    Full Text Available The Phosphorous discharge into the surface water led to excessive growth of algae and eutrophication in lakes and rivers. Therefore the phosphorus removal is important due to negative effect on water resources. The aim of this study was to investigat the modification of clinoptilolite and application of modified clinoptilolite for phosphorous adsorption from aqueous solution and isotherms and kinetics modeling. Hexadecyl Trimethyl Ammonium bromide (HDTMA-Br, Hexadecyl trimethyl Ammonium Chloride (HDTMA-Cl, Sodium Decyl Sulphate (SDS and Cetrimide-C were used for modification of clinoptilolite. Experiments were conducted using jar apparatus and batch system. The effect of pH, adsorbent doses, contact time, phosphate initial concentration and particle size were studied surveyed on phosphate adsorption by modified clinoptilolite. The most common isotherms and the kinetics adsorption equations were used for determination of adsorption rate and dynamic reaction. The results showed that maximum phosphate adsorption was obtained in the pH of 7 and contact time 90min. Also it was found with the increasing of phosphate initial concentration, phosphate removal efficiency decreased significantly. Langmuir No 2 showed a good correlation compared to other isotherms (R2=0.997. Maximum adsorption capacity was obtained in 20g/L adsorbent dose (22.73mg/g. Also Interaparticle diffusion kinetics well fits with experimental data (R2=0.999 with constant rate of 3.84mg/g min0.5. The result showed that modified clinoptilolite can be used successfully as low cost and effective absorbent for phosphate removal.

  3. Effects of dietary clinoptilolite and calcium levels on the performance and egg quality of commercial layers

    Directory of Open Access Journals (Sweden)

    DA Berto

    2013-09-01

    Full Text Available Among the different feed additives studied in poultry production, clinoptilolite, an aluminosilicate capable of adsorbing harmful substances and of improving live performance and egg and meat quality, was evaluated. The objective of the present study was to evaluate the influence of dietary clinoptilolite and calcium levels on the performance and egg quality of layers. In total, 576 layers were distributed according to a completely randomized experimental design in a 3 x 4 factorial arrangement (three calcium levels - 2.5, 3.1, or 3.7% and four clinoptilolite levels - 0.0, 0.15, 0.25, or 0.50%, with 12 treatments of six replicates of eight birds each. The experiment included four 28-d cycles. The experimental diets were based on corn and soybean meal. Results were submitted to analysis of variance and means were compared by the test of Tukey at 5% significance level using SISVAR statistical package. There was a significant interaction between the evaluated factors for egg production and feed conversion ratio per dozen eggs and egg mass. The lowest calcium level resulted in worse performance and eggshell quality. Clinoptilolite levels affected albumen and yolk content. It was concluded that up to 0.50% inclusion of clinoptilolite in layer diets does not benefit layer performance or eggshell quality. Although the inclusion of only 2.5% calcium in layer diets is not recommended, it is possible to add 3.1% because it promoted similar results as the recommended level of 3.7%.

  4. Zeolitization at uranium ore manifestation

    International Nuclear Information System (INIS)

    Petrosyan, R.V.; Buntikova, A.F.

    1981-01-01

    The process of zeolitization at uranium ore manifestation is studied. A specific type of low-temperature wall endogenous alteration of rocks due to the effect of primary acid solution with low content of carbonic acid is established. Leaching of calcium from enclosing rocks and its deposition in ore-accompanying calcium zeolites is a characteristic feature of wall-metasomatosis. Formation of desmin- calcite-laumontite and quartz-fluoroapatite of vein associations, including ore minerals (uranophane and metaotenite), is genetically connected with calcium metasomatosis. On the basis of the connection of ore minerals with endogeneous process of zeolitization a conclusion can be made on endogenous origin of uranophane and metaotenite [ru

  5. Zeolites occurrences prognostic using image spectral analysis in the volcanic sequences of Pequenos Lembombos, Mozambique

    Directory of Open Access Journals (Sweden)

    Elmidio Estévez-Cruz

    2018-01-01

    Full Text Available The research aims at evaluating the mineral potential of the basaltic lavas of the Movene Formation, to host microcrystalline zeolites. In order to attain this goal the methods of digital image processing, geological traversing and mineralogical analysis are used in an integrated approach. Landsat 8 images were processed using standard tools such as color composite, band ratios and supervised classification methods to understand the geology of the area and to identify areas spectrally similar to the minerals studied. The interpretation of the digital elevation model allowed to reveal structures and their combined use with the color compositions facilitated the lithologic discrimination. Fieldworks were carried out in the areas with the highest exposure of the basaltic lavas to identify and sample the zeolites. Finally, the collected samples were analyzed by X-ray diffraction in order to determine mineral composition. The study increased the existing geological knowledge about this important industrial mineral, mapping five mineral occurrences and revealing the most promising areas to host this type of deposits. Favorable sectors are circumscribed to the northern part of the working area, and they are generally in the proximity of rhyolites-basalts contact. The following mineral phases were also identified: heulandite-clinoptilolite, mesolite, mordenite, stilbite and laumontite

  6. Inclusion of Yucca schidigera extract and zeolite in the diet and its relationship to the apparent digestibility of nutrients and urinary pH in adult dogs

    Directory of Open Access Journals (Sweden)

    João Paulo Fernandes Santos

    2016-01-01

    Full Text Available ABSTRACT: This study aimed to evaluate the inclusion of Yucca schidigera extract and zeolite (Clinoptilolite added to the diets for dogs and its effect on apparent digestibility coefficients (ADC of diet components (dry matter, organic matter, crude protein, acid hydrolyzed fat, and energy and urinary pH. Twenty-one adult Beagles, males and females, body weight mean of 12.5±1.5kg and four and a half years old, distributed in a completely randomized design with seven replicates per treatment within three experimental treatments: control (no addition of Yucca schidigera and zeolite, Yucca schidigera (375ppm and zeolite (1%, administered in the encapsulated form of the supplement. The ADC of diet components and urinary pH were not affected by the inclusion of additives (P>0.05, except the ADC acid hydrolyzed fat showed reduction with Yucca schidigera supplementation compared to the other treatments (P<0.05. The addition of 375ppm of Yucca schidigera extract reduced the digestibility of dietary fat by dogs and both Yucca schidigera extract and zeolite did not affect the urinary pH of dogs.

  7. Does the combination of biochar and clinoptilolite enhance nutrient recovery from the liquid fraction of biogas digestate?

    DEFF Research Database (Denmark)

    Kocatürk, Nazli Pelin; Zwart, Kor; Bruun, Sander

    2017-01-01

    Concentrating nutrients on biochar and clinoptilolite and subsequently using the nutrient-enriched sorbents as a fertiliser could be an alternative way to manage nutrients in digestate. In this study, we investigated the use of biochar and clinoptilolite columns in removing ammonium, potassium......, orthophosphate and dissolved organic carbon (DOC) from the liquid fraction of digestate. Our objectives were to investigate the effect of the initial loading ratio between liquid and biochar on nutrient removal, and to investigate the effect of combining biochar with clinoptilolite on nutrient and DOC removal...... efficiency. Increasing the initial loading ratios increased nutrient concentrations on biochar to 8.61 mg NH4-N g(-1), 1.95 mg PO4-P g(-1) and 13.01 mg DOC g(-1), but resulted in decreasing removal efficiencies. The combination of biochar and clinoptilolite resulted in improved ammonium, potassium and DOC...

  8. Synthesis of high ion exchange zeolites from coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Querol, X.; Moreno, N.; Alastuey, A.; Juan, R.; Andres, J.M.; Lopez-Soler, A.; Ayora, C.; Medinaceli, A.; Valero, A. [CSIC, Barcelona (Spain)

    2007-07-01

    This study focuses on the synthesis at a pilot plant scale of zeolitic material obtained from the coal fly ashes of the Teruel and Narcea power plants in Spain. After the optimisation of the synthesis parameters at laboratory scale, the Teruel and Narcea fly ashes were selected as low and high glass fly ashes. The pilot plant scale experiments were carried out in a 10 m{sup 3} reactor of Clariant SA (Barcelona, Spain). The results allowed obtaining 1.1 and 2.2 tonnes of zeolitic material with 40 and 55% of NaP1 content, in two single batch experiments of 24 and 8 hours, for Teruel and Narcea fly ashes, respectively. The cation exchange capacities (CEC) of the final product reached 2.0 and 2.7 meq g{sup -1} for Teruel and Narcea zeolitic material, respectively, which are very close to the usual values reached by the high quality natural zeolitic products. Finally, with the aim of testing possible applications of the commercial NaP1-IQE and pilot plant NaP1-Narcea zeolitic products in water decontamination, efficiency for metal uptake from waste waters from electroplating baths was investigated.

  9. D2-H2 equilibration over γ-irradiated zeolites

    International Nuclear Information System (INIS)

    Novakova, J.; Wichterlova, B.

    1987-01-01

    D 2 -H 2 equilibration was studied at 77 and 298 K over HY, AlHY, HZSM-5 and Alsub(x)Osub(y)HZSM-5 zeolites which had been γ-irradiated at 77 and/or 298 K. The exchange rate was found to be higher at the lower temperature regardless of the temperature of irradiation. Moreover, at 77 K the exchange rates were similar and more stable over the individual zeolites than at 298 K, thus indicating a common reaction path at 77 K. The exchange rate at 298 K depended on the zeolite type: it was more stable and higher over HZSM-5 than over HY, and extra-lattice Al increased both these properties on HY as well as on HZSM-5. The reaction mechanism is discussed in connection with the nature of defects generated by γ-irradiation. (author)

  10. Zeolites modified with silver for the development of a water disinfection system; Zeolitas modificadas con plata para el desarrollo de un sistema de desinfeccion de agua

    Energy Technology Data Exchange (ETDEWEB)

    Aparicio V, S.

    2013-07-01

    In spite of great strides that have been taken in sanitation technologies, there still exist health problems due to microbiological contamination by water. The waterborne diseases have not been completely eradicated and are a big problem of economic interest and health. Moreover, the microbicidal properties of silver have been used for a long time. The use of silver as a disinfectant has many advantages; for example it inhibits a wide spectrum of microorganisms, it has oligo dynamic properties and owing its mechanisms of cell inactivation, it also does not allow the emergence of new resistant strains. In the present research, the kinetics of water disinfection with silver has been investigated, to develop small system for water disinfection, based in silver modified Mexican clinoptilolite. The chemical species of silver play a significant role in the disinfection processes. For this reason, in this work, were both the Ag{sup +} and nanoparticles of Ag{sup ο} considered. The synthesis of nanoparticles of Ag{sup ο} woes performed by thermal and chemical reduction. It was found that the chemical reduction of Ag{sup +} to Ag{sup ο} was more efficient because it presented more defined nano structures and better distribution than those of thermal reduction. Clinoptilolite of Taxco (Guerrero) was chosen to exchange the native ions from the clinoptilolite by Ag{sup +} from the aqueous medium, or to deposit the nanoparticles of Ag{sup ο} on this surface. These silver modified zeolitic materials were characterized by scanning electron microscopy (Sem), elemental analyses (EDS), X-ray diffraction (XRD) and neutron activation analysis (NAA). The results showed that the crystallographic structure of the clinoptilolite did not change during thermal and chemical reduction treatments of Ag{sup +} to obtain the nanoparticles of Ag{sup ο}. The bactericide activity of the silver modified zeolitic materials (with Ag{sup +} or nanoparticles of Ag{sup ο}) was evaluated on

  11. Modification of carbon paste electrode with Fe(III)-clinoptilolite nano-particles for simultaneous voltammetric determination of acetaminophen and ascorbic acid

    Energy Technology Data Exchange (ETDEWEB)

    Sharifian, Samira [Department of Chemistry, Shahreza Branch, Islamic Azad University, P.O. Box 311-86145, Shahreza, Isfahan (Iran, Islamic Republic of); Young Researchers and Elite Club, Shahreza Branch, Islamic Azad University, Shahreza (Iran, Islamic Republic of); Nezamzadeh-Ejhieh, Alireza, E-mail: arnezamzadeh@iaush.ac.ir [Department of Chemistry, Shahreza Branch, Islamic Azad University, P.O. Box 311-86145, Shahreza, Isfahan (Iran, Islamic Republic of); Young Researchers and Elite Club, Shahreza Branch, Islamic Azad University, Shahreza (Iran, Islamic Republic of); Razi Chemistry Research Center (RCRC), Shahreza Branch, Islamic Azad University, Isfahan (Iran, Islamic Republic of)

    2016-01-01

    A novel carbon paste electrode (CPE) modified with Fe(III)-exchanged clinoptilolite nano-particles (Fe(III)-NClino/CPE) was constructed and used for simultaneous voltammetric (CV, SqW and chronoamperometry) determination of ascorbic acid and acetaminophen. Raw and modified zeolites were characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM). The square wave peak current was linearly increased in the concentration ranges of 1.0 × 10{sup −9}–1.0 × 10{sup −2} mol L{sup −1} for ascorbic acid and 1.0 × 10{sup –10–}1.0 × 10{sup −2} mol L{sup −1} for acetaminophen with detection limits of 1.8 × 10{sup −9} mol L{sup −1} and 9.9 × 10{sup −10} mol L{sup −1}, respectively. The detection limits of 2.4 × 10{sup −10} mol L{sup −1} and 2.5 × 10{sup −11} mol L{sup −1} were also obtained for AA and AC in chronoamperometric measurements, respectively. The diffusion coefficients of 7.5 × 10{sup −5} cm{sup 2} s{sup −1} and 2.4 × 10{sup −5} cm{sup 2} s{sup −1} were respectively calculated for the oxidation of AC and AA by chronoamperometry. The proposed electrode exhibited high sensitivity and good stability, and would be valuable for the clinical assay of ascorbic acid and acetaminophen. - Graphical abstract: Comparison of CV voltammograms of the raw CPE (‘a’ and ‘b’) and the modified Fe(III)-NClino-CPE (‘c’ and ‘d’) confirmed good electrocatalytic activity of the modified electrode for voltammetric determination of AC and AA, so the peak currents significantly increased in presence of AA or AC species in solution (‘c’ and ‘d’). - Highlights: • Usefulness of Fe(III)-Nclino for simultaneous voltammetric determination of AA + AC • Electrocatalytic behavior of the electrode for AA determination • Complexation behavior of the electrode for AC determination • Considerable increase in sensitivity of the process • More efficient of nanonized clinoptilolite than the micronized one.

  12. Zeolite-zeolite composite composed of Y zeolite and single-crystal-like ZSM-5 zeolite: Fabricated by a process like “big fish swallowing little one”

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Meng; Li, Peng [Research Centre of Energy Chemical & Catalytic Technology, Taiyuan University of Technology, Taiyuan 030024 (China); Zheng, Jiajun, E-mail: zhengjiajun@tyut.edu.cn [Research Centre of Energy Chemical & Catalytic Technology, Taiyuan University of Technology, Taiyuan 030024 (China); Liu, Yujian [SINOPEC Research Institute of Petroleum Processing, Beijing, 100083 (China); Kong, Qinglan [Research Centre of Energy Chemical & Catalytic Technology, Taiyuan University of Technology, Taiyuan 030024 (China); Tian, Huiping [SINOPEC Research Institute of Petroleum Processing, Beijing, 100083 (China); Li, Ruifeng, E-mail: rfli@tyut.edu.cn [Research Centre of Energy Chemical & Catalytic Technology, Taiyuan University of Technology, Taiyuan 030024 (China)

    2017-06-15

    Zeolite-zeolite composite composed of Y and ZSM-5 zeolite was prepared using depolymerized Y as partial nutrients for the growth of ZSM-5. The as-synthesized samples were characterized by X-ray powder diffraction (XRD), FT-IR, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), N{sub 2} adsorption-desorption measurement and Thermogravimetric analysis (TG). Chemical equilibrium at the solution-crystal interface was changed because of the partially depolymerized Y zeolite, the conditions necessary for the growth of ZSM-5 were therefore obtained. ZSM-5 zeolite crystals nucleated and grew on the interface, and Y zeolite crystals were then gradually swallowed by the growing single-crystal-like ZSM-5. - Graphical abstract: Y zeolite crystals in the hydrothermal system were partially depolymerized and an ambience in favor of the formation of ZSM-5 was formed, and ZSM-5 zeolite crystals nucleated and grew up on the external surfaces of Y zeolite crystals. As a consequence, Y zeolite crystals were swallowed by single-crystal-like ZSM-5. - Highlights: • Zeolite composite is composed by Y zeolite and single-crystal-like ZSM-5. • A composite material formed by a process like “big fish swallowing little one”. • Ratio of two zeolites in the as-synthesized sample can be adjusted.

  13. Novel modified zeolites for energy-efficient hydrocarbon separations.

    Energy Technology Data Exchange (ETDEWEB)

    Arruebo, Manuel (University of Colorado, Boulder, CO); Dong, Junhang; Anderson, Thomas (Burns and McDonnell, Kansas City, MO); Gu, Xuehong; Gray, Gary (Goodyear Chemical Company, Akron, OH); Bennett, Ron (Goodyear Chemical Company, Akron, OH); Nenoff, Tina Maria; Kartin, Mutlu; Johnson, Kaylynn (Goodyear Chemical Company, Akron, OH); Falconer, John (University of Colorado, Boulder, CO); Noble, Richard (University of Colorado, Boulder, CO)

    2006-11-01

    We present synthesis, characterization and testing results of our applied research project, which focuses on the effects of surface and skeletal modification of zeolites for significant enhancements in current hydrocarbon (HC) separations. Zeolites are commonly used by the chemical and petroleum industries as catalysts and ion-exchangers. They have high potential for separations owing to their unique pore structures and adsorption properties and their thermal, mechanical and chemical properties. Because of zeolites separation properties, low cost, and robustness in industrial process, they are natural choice for use as industrial adsorbents. This is a multidisciplinary effort to research, design, develop, engineer, and test new and improved materials for the separation of branched vs. linear organic molecules found in commercially important HC streams via adsorption based separations. The focus of this project was the surface and framework modification of the commercially available zeolites, while tuning the adsorption properties and the selectivities of the bulk and membrane separations. In particular, we are interested with our partners at Goodyear Chemical, on how to apply the modified zeolites to feedstock isoprene purification. For the characterization and the property measurements of the new and improved materials powder X-ray diffraction (PXRD), Residual Gas Analyzer-Mass Spectroscopy (RGA-MS), Electron Microscopy (SEM/EDAX), temperature programmed desorption (TPD) and surface area techniques were utilized. In-situ carbonization of MFI zeolite membranes allowed for the maximum separation of isoprene from n-pentane, with a 4.1% enrichment of the binary stream with n-pentane. In four component streams, a modified MFI membrane had high selectivities for n-pentane and 1-3-pentadiene over isoprene but virtually no separation for the 2-methyl-2-butene/isoprene pair.

  14. Metal immobilization in soils using synthetic zeolites

    NARCIS (Netherlands)

    Osté, L.A.; Lexmond, T.M.; Riemsdijk, van W.H.

    2002-01-01

    In situ immobilization of heavy metals in contaminated soils is a technique to improve soil quality. Synthetic zeolites are potentially useful additives to bind heavy metals. This study selected the most effective zeolite in cadmium and zinc binding out of six synthetic zeolites (mordenite-type,

  15. Zeolite from fly ash: synthesis and characterization

    Indian Academy of Sciences (India)

    ... area of the product was found to be 383 m2/g with high purity. The crystallinity of the prepared zeolite was found to change with fusion temperature and a maximum value was obtained at 823 K. The cost of synthesized zeolite was estimated to be almost one-fifth of that of commercial 13X zeolite available in the market.

  16. Removal of indigo blue using clinoptilolite-Fe; Remocion de azul indigo utilizando clinoptilolita-Fe

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez S, E. E.; Colin C, A. [Universidad Autonoma del Estado de Mexico, Facultad de Quimica, Paseo Tollocan esquina Paseo Colon s/n, Toluca 50180, Estado de Mexico (Mexico); Solache R, M. J. [ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico)], e-mail: edithgs77@yahoo.com.mx

    2008-07-01

    The removal of indigo blue from aqueous solutions was evaluated using modified clinoptilolite with Fe (Z-Fe) which was characterized by SEM, EDS analysis and specific area (BET). The process followed the kinetics of pseudo-second order and Langmuir isotherm. Sorption capacity obtained was 18 mg g{sup -1} and a solid-liquid ratio 10 g L{sup -1}. (Author)

  17. Characterization of modified zeolite as microbial immobilization media on POME anaerobic digestion

    Science.gov (United States)

    Cahyono, Rochim B.; Ismiyati, Sri; Ginting, Simparmin Br; Mellyanawaty, Melly; Budhijanto, Wiratni

    2018-03-01

    As the world’s biggest palm oil producer, Indonesia generates also huge amount of Palm Oil Mill Effluent (POME) wastewater and causes serious problem in environment. In conventional method, POME was converted into biogas using lagoon system which required extensive land area. Anaerobic Fluidized Bed Reactor (AFBR) proposes more effective biogas producing with smaller land area. In the proposed system, a immobilization media would be main factor for enhancing productivity. This research studied on characterization of Lampung natural zeolite as immobilization media in the AFBR system for POME treatment. Various activation method such as physical and chemical were attempted to create more suitable material which has larger surface area, pore size distribution as well as excellent surface structures. The physical method was applied by heating up the material till 400°C while HCl was used on the chemical activation. Based on the result, the chemical activation increased the surface area significantly into 71 m2/g compared to physical as well as original zeolite. The strong acid material was quite effective to enforce the impurities within zeolite pore structure compared to heating up the material. According to distribution data, the Lampung zeolite owned the pore size with the range of 3 – 5 μm which was mesopore material. The pore size was appropriate for immobilization media as it was smaller than size of biogas microbial. The XRD patterns verified that chemical activation could maintain the zeolite structure as the original. Obviously, the SEM photograph showed apparent structure and pore size on the modified zeolite using chemical method. The testing of modified zeolite on the batch system was done to evaluate the characterization process. The modified zeolite using chemical process resulted fast reduction of COD and stabilized the volatile fatty acid as the intermediate product of anaerobic digestion, especially in the beginning of the process. Therefore, the

  18. Improvement of adsorption properties of zeolites and their characterization - 15133

    International Nuclear Information System (INIS)

    Mimura, H.; Rahman, M.S.; Yamagishi, I.; Matsukura, M.; Kuroda, A.

    2015-01-01

    The improvement of adsorption properties of radioactive Cs and Sr was evaluated for different kinds of zeolites treated with various methods; calcination, conditioning, surface alteration, fine-granulation, mixture-granulation, honeycomb modeling and loading. Their characteristics were examined by instrumental analyses (SEM, EPMA, XRD, IR) and batch and column adsorption methods. As for the calcination treatment, the calcined natural mordenite was prepared by heat treatment at different temperatures up to 1000 C. degrees. The improvement of adsorption rate was observed for the calcined mordenite at 500 C. degrees. The conditioning with H + , Na + and K + ions was ineffective for the enhancement of adsorption properties of mordenites. Comparing the adsorption properties of Sr 2+ for A-type zeolites having various particle sizes, the adsorption kinetics tended to increase with decreasing particle size in the order of A powder > A0.5(0.5 mm) > A0.5HP(0.5 mm) > A1.5(1.5 mm). In particular, A0.5HP with no binder exhibited a relatively large uptake (%) of Sr 2+ above 80% in seawater, which is the largest value in the conventional granular zeolites. For multi-nuclide decontamination, composite zeolites such as AMXα and AMXβ were prepared by mixing three kinds of zeolites; A zeolite, Mordenite and X zeolite. The mixing ratios of AMXα and AMXβ were 1: 1: 1 and 0.5: 1: 0.5, respectively. Composite zeolites had relatively large uptake (%) above 95% for Cs + , Sr 2+ and Co 2+ ions in 1/10 diluted seawater. Zeolites honeycomb can be used for the continuous concentration of Cs + and Sr 2+ ions in seawater. Uptake (%) of Cs + ions for mordenite honeycomb at V/m= 100 cm 3 /g was estimated to be 86.8% and 57.9% within 18 h in pure water and 15 h in seawater, respectively. Uptake (%) of Sr 2+ ions for A-type zeolite honeycomb was estimated to be 99.2% within 24 h and 69.0% within 3 h in pure water and seawater, respectively. As for the Cs adsorption on mordenite honeycomb at a

  19. Enhanced ammonia nitrogen removal using consistent ammonium exchange of modified zeolite and biological regeneration in a sequencing batch reactor process.

    Science.gov (United States)

    Wei, Yun Xia; Ye, Zheng Fang; Wang, Yao Long; Ma, Ming Guang; Li, Yan Feng

    2011-01-01

    Utilizing preferential ion exchange of the modified zeolite, the zeo-sequencing batch reactor (SBR) is recommended for a new nitrogen removal process. In this study, natural zeolite was modified by sodium chloride to enhance sorption capacity for ammoniacal nitrogen. The untreated and treated zeolite was characterized by XPS and XRD techniques. The sorption isotherm tests showed that equilibrium sorption data were better represented by the Langmuir model than by the Freundlich model. Treatment of natural zeolite by sodium chloride increased the sorption capacity for ammoniacal nitrogen removal from aqueous solutions. As a result of the continuous bioregeneration of ammonium saturated zeolite-floc in the SBR, the nitrogen removal efficiency of the zeo-SBR was relatively ideal. Scanning electron microscopy results showed that microbes were abundant in the zeo-SBR process.

  20. EFFECT OF TIME AND TEMPERATURE ON ISOMERIZATION REACTION OF ?-PINENEUSING CATALYST ZR 4+ Nanik Wijayati, Supartono, Nuni Widiarti, Tri Handayani /NATURAL ZEOLITE

    Directory of Open Access Journals (Sweden)

    Nanik Wijayati

    2016-03-01

    Full Text Available Effects of time and temperature on ?-pinene isomerization reaction using catalysts Zr/natural zeolitewas studied. Characterization of the catalysts include: crystallinity, observed using X-Ray Diffraction, count Zr 4+ carried observed using X-Ray Fluorescence, area and porosity catalyst was observed using the Surface Area Analyzer, and acidity catalyst observed through gravimetric method. Isomerization reaction carried out in a batch reactor with temperature variations 90, 120 and 150 C and reaction time variations of 60, 90, 120, 150 and 180 minutes. Best results of isomerisation in this study was obtained at 150 derajat C with a reaction time of 180 minutes. Kindsof isomer obtained was observed using GCMS. Catalyst characterization results indicate that modification of the catalyst by cation Zr increases the acidity from 2.76 to 6.64 mmol/g and does not damage the crystal structure significantly. The highest product conversion in this research is 9.24%, less than the maximum results caused by pre-treatment of the catalyst produces a low area. Thus, temperature and reaction time affect the concentration of ? pinene isomerization product in addition to the effect of the catalyst used.

  1. Initial bacterial deposition on bare and zeolite-coated aluminum alloy and stainless steel.

    Science.gov (United States)

    Chen, Gexin; Beving, Derek E; Bedi, Rajwant S; Yan, Yushan S; Walker, Sharon L

    2009-02-03

    In this study, the impact of zeolite thin film coatings on bacterial deposition and "biofouling" of surfaces has been investigated in an aqueous environment. The synthesis of two types of zeolite coatings, ZSM-5 coated on aluminum alloy and zeolite A coated on stainless steel, and the characterization of the coated and bare metal surfaces are described. The extent of cell deposition onto the bare and zeolite-coated aluminum alloy and stainless steel surfaces is investigated in a parallel plate flow chamber system under a laminar flow conditions. The initial rates of bacterial transfer to the various surfaces are compared by utilizing a marine bacterium, Halomonas pacifica g, under a range of ionic strength conditions. H. pacifica g deposited onto bare metal surfaces to a greater extent as compared with cells deposited onto the zeolite coatings. The surface properties found to have the most notable effect on attachment are the electrokinetic and hydrophobicity properties of the metal and zeolite-coated surfaces. These results suggest that a combination of two chemical mechanisms-hydrophobic and electrostatic interactions-contribute to the antifouling nature of the zeolite surface. Additional observations on the relative role of the hydrodynamic and physical phenomena are also discussed.

  2. Removal of Boron from aqueous solutions by adsorption using fly ash, zeolite and demineralized lignite

    OpenAIRE

    Yüksel, Seren; Yuksel, Seren; Yürüm, Yuda; Yurum, Yuda

    2009-01-01

    In the present study for the purpose of removal of boron from water by adsorption using adsorbents like fly ash, natural zeolite and demineralized lignite was investigated. Boron in water was removed with fly ash, zeolite and demineralized lignite with different capacities. 94% boron was removed using fly ash. Batch experiments were conducted to test removal capacity, to obtain adsorption isotherms, thermodynamic and kinetic parameters. Boron removal by all adsorbents was affected by pH of...

  3. Regioselective nitration of aromatic substrates in zeolite cages

    Indian Academy of Sciences (India)

    Unknown

    meet market demand, Choudary et al have achieved a zeolite-based methodology for the nitration of aromatic compounds.13 They have carried out nitration of toluene with various zeolite catalysts and zeolite beta of different Si/Al ratios. Zeolite beta has proved to be the best catalyst among the zeolites used in terms of ...

  4. High-pressure alchemy on a small-pore zeolite

    Science.gov (United States)

    Lee, Y.

    2011-12-01

    While an ever-expanding variety of zeolites with a wide range of framework topology is available, it is desirable to have a way to tailor the chemistry of the zeolitic nanopores for a given framework topology via controlling both the coordination-inclusion chemistry and framework distortion/relaxation. This is, however, subjected to the ability of a zeolitic nanopore to allow the redistribution of cations-water assembly and/or insertion of foreign molecules into the pores and channels. Small-pore zeolites such as natrolite (Na16Al16Si24O80x16H2O), however, have been known to show very limited capacity for any changes in the confinement chemistry. We have recently shown that various cation-exchanged natrolites can be prepared under modest conditions from natural sodium natrolite and exhibit cation-dependent volume expansions by up to 18.5% via converting the elliptical channels into progressively circular ones. Here, we show that pressure can be used as a unique and clean tool to further manipulate the chemistry of the natrolite nanopores. Our recent crystallographic and spectroscopic studies of pressure-insertion of foreign molecules, trivalent-cation exchange under pressure, and pressure-induced inversion of cation-water coordination and pore geometry in various cation-exchanged natrolites will be presented.

  5. Ethylene formation by dehydration of ethanol over medium pore zeolites

    Science.gov (United States)

    Gołąbek, Kinga; Tarach, Karolina A.; Filek, Urszula; Góra-Marek, Kinga

    2018-03-01

    In this work, the role of pore arrangement of 10-ring zeolites ZSM-5, TNU-9 and IM-5 on their catalytic properties in ethanol transformation were investigated. Among all the studied catalysts, the zeolite IM-5, characterized by limited 3-dimensionality, presented the highest conversion of ethanol and the highest yields of diethyl ether (DEE) and ethylene. The least active and selective to ethylene and C3 + products was zeolite TNU-9 with the largest cavities formed on the intersection of 10-ring channels. The catalysts varied, however, in lifetime, and their deactivation followed the order: IM-5 > TNU-9 > ZSM-5. The processes taking place in the microporous zeolite environment were tracked by IR spectroscopy and analysed by the 2D correlation analysis (2D COS) allowing for an insight into the nature of chemisorbed adducts and transition products of the reaction. The cage dimension was found as a decisive factor influencing the tendency for coke deposition, herein identified as polymethylated benzenes, mainly 1,2,4-trimethyl-benzene.

  6. Synthesis and testing of nanosized zeolite Y

    Science.gov (United States)

    Karami, Davood

    This work focuses on the synthesis and testing of nanosized zeolite Y. The synthesis formulations of faujasite-type structure of zeolite Y prepared in nanosized form are described. The synthetic zeolite Y is the most widely employed for the preparation of fluid catalytic cracking (FCC) catalysts. The synthesis of zeolite Y is very complicated process. The mean particle size of zeolite Y is 1800 nm. The major challenge of this work involved reducing this average particle size to less than 500 nm. The preliminary experiments were conducted to obtain the pure zeolite Y using the soluble silicates as a silica source. This was achieved by applying the experimental design approach to study the effects of many parameters. The ageing time turned out to be the most significant variable affecting product purity. Based on the preliminary results, a detailed investigation was carried out to determine the effects of silica-alumina precursor preparations on zeolite Y synthesis. Aluminosilicate precursors were prepared by gelling and precipitation of soluble silicate. The as-prepared precursors were used for the hydrothermal synthesis of zeolite Y. The procedure of the precipitation of soluble silicate yielded pure zeolite Y at the conventional synthesis conditions. The extent of purity of zeolite Y depends on the surface areas of aluminosilicate precursors. A novel approach to zeolite Y synthesis was employed for the preparation of the pure nanosized zeolite Y. This was achieved by applying the method of impregnation of precipitated silica. This novel method of impregnation for zeolite Y preparation allows eliminating the vigorous agitation step required for the preparation of a homogeneous silica solution, thereby simplifying the synthesis of zeolite Y in one single vessel. In case of the synthesis of nanosized zeolite Y, the effect of varying the organic templates on the formation of nanosized particles of zeolite Y was investigated, while all other reaction parameters were

  7. Evaluation of synthetic zeolite as engineering passive permeable reactive barrier

    International Nuclear Information System (INIS)

    Ibrahim, O.A.A.

    2011-01-01

    The presence of toxic pollutants in groundwater brings about significant changes in the properties of water resources and has to be avoided in order to preserve the environmental quality. Heavy metals are among the most dangerous inorganic water pollutants, that related to many anthropogenic sources and their compounds are extremely toxic. The treatment of contaminated groundwater is among the most difficult and expensive environmental problems. Over the past years, permeable reactive barriers have provided an increasingly important role in the passive insitu treatment of contaminated groundwater. There are a large number of materials that are able to immobilize contaminants by sorption, including granulated active carbon, zeolite, montmorillonite, peat, compost, sawdust, etc. Zeolite X is a synthetic counterpart of the naturally occurring mineral Faujasite. It has one of the largest cavities and cavity entrances of any known zeolites. The main aim of this work is to examine the possibility of using synthetic zeolite X as an engineering permeable reactive barrier to remove heavy metals from a contaminated groundwater. Within this context, the following investigations were carried out: 1. Review on the materials most commonly used as engineered permeable reactive barriers to identify the important features to be considered in the examination of the proposed permeable reactive barrier material (zeolite X). 2. Synthesis of zeolite X and characterization of the synthesized material using different techniques. 3. Batch tests were carried out to characterize the equilibrium and kinetic sorption properties of the synthesized zeolite X towards the concerned heavy metals; zinc and cadmium ions. 4. Column tests were also performed to determine the design factors for permeable reactive barrier against zinc and cadmium ions solutions.Breakthrough curves measured in such experiments used to determine the hydrodynamic dispersion coefficients for both metal ions. 5. Analytical

  8. The potential of melt-mixed polypropylene-zeolite blends in the removal of heavy metals from aqueous media

    Science.gov (United States)

    Motsa, Machawe M.; Thwala, Justice M.; Msagati, Titus A. M.; Mamba, Bhekie B.

    The continued deterioration of the water quality in natural water sources such as rivers and lakes has led to tensions amongst relevant stakeholders to such an extent that cooperative water resource management is being regarded as an ideal solution to culminate conflicts and maximise the benefits. The desire to develop technologies that combine the three most important aspects of integrated water resource management (namely social, economic and environmental) has been encouraged by relevant authorities. This paper therefore reports the application of clinoptilolite-polypropylene (CLI-PP) blends/composites for the removal of lead from aqueous media. Just like many other heavy metals, lead poses a threat to water and soil quality as well as to plant and animal health. The findings on the adsorption behaviour of clinoptilolite-polypropylene composites with respect to Pb 2+ are also reported here, with the aim of extending its application to wastewater and environmental water purification. The batch equilibrium adsorption method was employed and the influence of contact time, pH, initial metal-ion concentration, temperature and pretreatment was determined. The optimum pH was found to be between pH 6 and pH 8 while the maximum sorption of lead at optimal pH was 95%. No big difference was observed between the adsorption behaviour of composites functionalised with 20% and 30% clinoptilolite, respectively. The pretreatment with HCl and NaCl made a slight difference to the adsorption capacity of composites.

  9. Color and shade parameters of ultramarine zeolitic pigments synthesized from kaolin waste

    Energy Technology Data Exchange (ETDEWEB)

    Menezes, Raquel Aranha de; Paz, Simone Patricia Aranha da; Angelica, Romulo Simoes; Neves, Roberto de Freitas; Pergher, Sibele Berenice Castella, E-mail: raquel_arn@hotmail.com [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Inst. de Geociencias. Grupo de Mineralogia e Geoquimica Aplicada

    2014-08-15

    Ultramarine pigments were successful synthesized from zeolite A obtained from kaolin waste. This waste has been used as an excellent source of silicon and aluminum for zeolite synthesis because of its high kaolinite concentrations and low contents of other accessory minerals. The cost is naturally less than the industrialized product. Color additives (Sulfur and Sodium Carbonate) were mixed with different proportions of zeolite A and further calcined for 5 h at 500 °C. They were characterized by XRD and XRF in addition to visual classification by color and shade. These products show colors from blue to green at different shades, both influenced by the amount of additives and cooling rate after calcination. Thus, a different quantity of the same additives in the same zeolitic matrix provides an increase in the color intensity. Cooling rate after calcination induces the color change which is substantially important in the pigments production. (author)

  10. Synthesis and characterization of zeolite P using technical-grade materials

    CERN Document Server

    Aghabozorg, H R; Aghabozorg, H R; Sharif, M

    2001-01-01

    Research attempts on zeolites show structural and industrial importance of these inorganic compounds. In this regard, the synthesis of zeolites is of great importance, because their natural occurring counterparts are often impure. Zeolite Na-P with a silicon to aluminium ratio of one has a better ion exchange capacity than Na-A and can be used as a detergent builder. In this work, zeolite Na-P of high purity was successfully synthesized using commercial silica and alumina sources. parameters such as H sub 2 O:A1 sub 2 O sub 3 and SiO sub 2 :A1 sub 2 O sub 3 molar ratios and crystallization temperature and time were investigated. So that the optimum condition was obtained. X-ray powder diffraction, infrared, scanning electron microscopy and elemental analysis were utilized for the characterization of the product.

  11. Color and shade parameters of ultramarine zeolitic pigments synthesized from kaolin waste

    International Nuclear Information System (INIS)

    Menezes, Raquel Aranha de; Paz, Simone Patricia Aranha da; Angelica, Romulo Simoes; Neves, Roberto de Freitas; Pergher, Sibele Berenice Castella

    2014-01-01

    Ultramarine pigments were successful synthesized from zeolite A obtained from kaolin waste. This waste has been used as an excellent source of silicon and aluminum for zeolite synthesis because of its high kaolinite concentrations and low contents of other accessory minerals. The cost is naturally less than the industrialized product. Color additives (Sulfur and Sodium Carbonate) were mixed with different proportions of zeolite A and further calcined for 5 h at 500 °C. They were characterized by XRD and XRF in addition to visual classification by color and shade. These products show colors from blue to green at different shades, both influenced by the amount of additives and cooling rate after calcination. Thus, a different quantity of the same additives in the same zeolitic matrix provides an increase in the color intensity. Cooling rate after calcination induces the color change which is substantially important in the pigments production. (author)

  12. A Review of the Application of Zeolite Materials in Warm Mix Asphalt Technologies

    Directory of Open Access Journals (Sweden)

    Agnieszka Woszuk

    2017-03-01

    Full Text Available Among warm mix asphalt (WMA technologies, asphalt foaming techniques offer high potential in terms of decreasing production temperature. Reluctance of manufacturers to introduce this technology is connected with the concerns of a large investment costs. However, there are known additives which, through asphalt foaming, allow a decrease in temperatures by approximately 30 °C; the use of these additives do not involve expensive investment in order to change the asphalt mix production method. These additives are zeolites, that is, minerals of the aluminosilicate group, the crystalline structure of which contains water bound in a specific way. Its release, at mix asphalt production temperatures, causes asphalt foaming. It is currently known that zeolites can be used in WMA, including natural and synthetic zeolites obtained using chemical reagents and waste. This review presents the results of studies of WMA technology, including the effects of zeolite addition on asphalt properties and mix asphalt, as well as related environmental, economic, and technological benefits.

  13. Direct activation of microcrystalline zeolites

    NARCIS (Netherlands)

    Ortiz-Iniesta, Maria Jesus; Heeres, Hero Jan; Melian-Cabrera, Ignacio

    2013-01-01

    In this work a direct activation route of zeolites is assessed. It consists of NH4-exchanging the as-synthesized solids before removing the organic template. Calcination afterwards serves to combust the organic template and creates the Bronsted sites directly; thus applying merely a single thermal

  14. Fixing noble gas in zeolites

    International Nuclear Information System (INIS)

    Rocha Dorea, A.L. da.

    1980-09-01

    In order to increase safety during the long-term storage of Kr-85 it has been proposed to encaosulate this gas in zeolite 5A. Due to the decay heat of Kr-85 it is expected, however, that the inorganic matrix will be at an increased temperature over several decades. Below 600 0 C only very small Kr-desorption rates are observed when a linear temperature gradient is applied to a loaded 5A zeolite sample. If heating is interrupted and the temperature kept konstant at a certain value (>600 0 C), it is observed that the desorption rate either decreased below the detection limit or stayed constant at some measurable value. The overall activation energy in the temperature range 570 0 C-745 0 C is found to be 250 kJ/mol. At temperature above 790 0 C the total encapsulated gas is rapidly liberated. No significant leakage was apparent from zeolite 5A samples containing between 19 and 57 cm 3 STP Kr/g kept at 200 0 C for up to 2500 h and 400 0 C for up to 3500 h. From these studies it is found that type 5A zeolites are particularly suitable as a matrix for the inmobilization of Kr-85. (Author) [pt

  15. Hydrogen Selective Exfoliated Zeolite Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Tsapatsis, Michael [Univ. of Minnesota, Minneapolis, MN (United States). Department of Chemical Engineering and Materials Science; Daoutidis, Prodromos [Univ. of Minnesota, Minneapolis, MN (United States). Department of Chemical Engineering and Materials Science; Elyassi, Bahman [Univ. of Minnesota, Minneapolis, MN (United States). Department of Chemical Engineering and Materials Science; Lima, Fernando [Univ. of Minnesota, Minneapolis, MN (United States). Department of Chemical Engineering and Materials Science; Iyer, Aparna [Univ. of Minnesota, Minneapolis, MN (United States). Department of Chemical Engineering and Materials Science; Agrawal, Kumar [Univ. of Minnesota, Minneapolis, MN (United States). Department of Chemical Engineering and Materials Science; Sabnis, Sanket [Univ. of Minnesota, Minneapolis, MN (United States). Department of Chemical Engineering and Materials Science

    2015-04-06

    The objective of this project was to develop and evaluate an innovative membrane technology at process conditions that would be representative of Integrated Gasification Combined Cycle (IGCC) advanced power generation with pre-combustion capture of carbon dioxide (CO2). This research focused on hydrogen (H2)-selective zeolite membranes that could be utilized to separate conditioned syngas into H2-rich and CO2-rich components. Both experiments and process design and optimization calculations were performed to evaluate the concept of ultra-thin membranes made from zeolites nanosheets. In this work, efforts in the laboratory were made to tackle two fundamental challenges in application of zeolite membranes in harsh industrial environments, namely, membrane thickness and membrane stability. Conventional zeolite membranes have thicknesses in the micron range, limiting their performance. In this research, we developed a method for fabrication of ultimately thin zeolite membranes based on zeolite nanosheets. A range of layered zeolites (MWW, RWR, NSI structure types) suitable for hydrogen separation was successfully exfoliated to their constituent nanosheets. Further, membranes were made from one of these zeolites, MWW, to demonstrate the potential of this group of materials. Moreover, long-term steam stability of these zeolites (up to 6 months) was investigated in high concentrations of steam (35 mol% and 95 mole%), high pressure (10 barg), and high temperatures (350 °C and 600 °C) relevant to conditions of water-gas-shift and steam methane reforming reactions. It was found that certain nanosheets are stable, and that stability depends on the concentration of structural defects. Additionally, models that represent a water-gas-shift (WGS) membrane reactor equipped with the zeolite membrane were developed for systems studies. These studies had the aim of analyzing the effect of the membrane reactor integration into IGCC plants

  16. Highly mesoporous single-crystalline zeolite beta synthesized using a nonsurfactant cationic polymer as a dual-function template

    KAUST Repository

    Zhu, Jie

    2014-02-12

    Mesoporous zeolites are useful solid catalysts for conversion of bulky molecules because they offer fast mass transfer along with size and shape selectivity. We report here the successful synthesis of mesoporous aluminosilicate zeolite Beta from a commercial cationic polymer that acts as a dual-function template to generate zeolitic micropores and mesopores simultaneously. This is the first demonstration of a single nonsurfactant polymer acting as such a template. Using high-resolution electron microscopy and tomography, we discovered that the resulting material (Beta-MS) has abundant and highly interconnected mesopores. More importantly, we demonstrated using a three-dimensional electron diffraction technique that each Beta-MS particle is a single crystal, whereas most previously reported mesoporous zeolites are comprised of nanosized zeolitic grains with random orientations. The use of nonsurfactant templates is essential to gaining single-crystalline mesoporous zeolites. The single-crystalline nature endows Beta-MS with better hydrothermal stability compared with surfactant-derived mesoporous zeolite Beta. Beta-MS also exhibited remarkably higher catalytic activity than did conventional zeolite Beta in acid-catalyzed reactions involving large molecules. © 2014 American Chemical Society.

  17. Synthesis and characterization of zeolite from coal ashes modified by cationic surfactant; Sintese e caracterizacao de zeolita de cinzas de carvao modificada por surfactante cationico

    Energy Technology Data Exchange (ETDEWEB)

    Fungaro, D.A.; Borrely, S.I., E-mail: dfungaro@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2012-01-15

    Zeolite synthesized from coal fly ash was modified with different concentrations (2 and 20 mmol.L{sup -1}) of hexadecyltrimethylammonium bromide (HDTMA-Br). The Non-Modified Zeolite (NMZ) and Surfactant-Modified Zeolites (SMZ) were characterized by X-ray fluorescence spectrometry, X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, thermogravimetric analysis, among others. The SMS presented negative charge probably due to the formation of a partial bilayer of HDTMA on exchangeable active sites on the external surface of NMZ. A decrease in surface area was observed for SMZ as compared to NMZ indicating zeolite surface coverage with HDTMA-Br molecules. The crystalline nature of the zeolite remained intact after adsorption of surfactant and heating for drying. FTIR analysis indicated that there were no significant changes in the structure of the zeolite after adsorption of surfactant. (author)

  18. Removal of heavy metals from water by zeolite mineral chemically modified. Mercury as a particular case

    International Nuclear Information System (INIS)

    Gebremedhin H, T.

    2002-01-01

    Research works on the removal of mercury from water by zeolite minerals show that a small quantity of this element is sorbed. In this work the mercury sorption from aqueous solutions in the presence and absence of Cu(l l), Ni(l l) and/or Zn(l l) by a Mexican zeolite mineral, natural and modified by cisteaminium chloride or cistaminium dichloride, was investigated in acidic p H. The zeolite minerals were characterized by X- Ray diffraction Ftir, scanning electron microscopy and semiquantitative elemental analysis (EDS), surface area analysis (BET) and thermogravimetric analysis (TGA). Mercury from aqueous solutions was quantified by Atomic absorption spectroscopy. The amount of sulphur on the zeolite samples treated with Na CI and modified with cisteaminium chloride (0.375 mmol/g) or cistaminium dichloride(0.475 mmol/g) was found to be higher than that of the zeolite minerals modified with cisteaminium chloride and cistaminium dichloride without treating them with Na CI. The amount of sulphur on the zeolite minerals modified with thiourea was the lowest. The diffusion coefficients and sorption isotherms for mercury were determined in the natural, treated with Na CI and, treated with Na CI and then modified with the cisteaminium chloride or cistaminium dichloride zeolite samples. The retention of mercury was the highest for the zeolite minerals treated Na CI and then modified with cisteaminium chloride or cistaminium dichloride, with adsorption capacity of 0.0511 and 0.0525 mmol Hg/g, respectively. In this research work, it was found that the retention of mercury by the modified minerals was not affected by the presence of Cu (Il), Zn(l l) y Ni (I l) under the experimental conditions. (Author)

  19. Spin probes of chemistry in zeolites

    International Nuclear Information System (INIS)

    Werst, D.W.; Trifunac, A.D.

    1997-09-01

    Electron spin resonance (EPR) studies in zeolites are reviewed in which radiolysis was used to ionize the zeolite lattice, create reactive intermediates, spin label reaction products and to provide a window onto chemistry and transport of adsorbates and matrix control of chemistry. The review examines reactions of radical cations and the influence of the geometry constraints inside the zeolite, explores how zeolite model systems can be used to learn about energy and charge transfer in solids and illustrates the use of radiolysis and EPR for in situ spectroscopic studies of solid-acid catalysis. The various spin probes created inside the zeolite pores report on properties of the zeolites as well as shed light on radiolytic processes

  20. Synthesis, Characterization and Application of Hydrophobic Zeolites

    OpenAIRE

    Heidari, Rulis

    2016-01-01

    The aim of the thesis was to design and synthesize a type of zeolite with the characteristics of hydrophobicity, high porosity, and proper pore size, which can be used for high-performance adsorption of ethanol from aqueous solution. In addition, the aim was to synthesize hydrophobic microporous zeolites including theoretic and experimental content. The experiment was carried out using hydroxide basic system and hydrogen fluoride neutral based on hydrothermal methods. Pure silica zeolites...

  1. 85Kr storage by zeolite encapsulation

    International Nuclear Information System (INIS)

    Brown, R.A.; Hoza, M.; Knecht, D.A.

    1976-01-01

    The technology of 85 Kr storage by zeolite encapsulation is described. The prcess of encapsulation takes place at high temperatures and pressures, and involves the activated diffusion of krypton into zeolite cages. Experimental results for krypton encapsulation in various zeolites are reviewed and discussed. Activated diffusion parameters determined by measuring krypton leakage rates from zeolites at high temperatures and low pressures are used to estimate leakage rates of 85 Kr during long-term storage. The potential safety benefits are determined for krypton-85 storage by encapsulation in sodalite. Requirements for pilot-scale and process-scale development are discussed briefly

  2. Increased thermal conductivity monolithic zeolite structures

    Science.gov (United States)

    Klett, James; Klett, Lynn; Kaufman, Jonathan

    2008-11-25

    A monolith comprises a zeolite, a thermally conductive carbon, and a binder. The zeolite is included in the form of beads, pellets, powders and mixtures thereof. The thermally conductive carbon can be carbon nano-fibers, diamond or graphite which provide thermal conductivities in excess of about 100 W/mK to more than 1,000 W/mK. A method of preparing a zeolite monolith includes the steps of mixing a zeolite dispersion in an aqueous colloidal silica binder with a dispersion of carbon nano-fibers in water followed by dehydration and curing of the binder is given.

  3. Remoção de Pb2+ e Cr3+ em solução por zeólitas naturais associadas a rochas eruptivas da formação serra geral, bacia sedimentar do Paraná Removal of Pb2+ and Cr3+ from aqueous solution by natural zeolites associated with eruptive rocks from the serra geral formation, Paraná sedimentary basin

    Directory of Open Access Journals (Sweden)

    Mirian Chieko Shinzato

    2009-01-01

    Full Text Available The capacity of natural zeolites and its host rock (dacite to remove Pb2+ and Cr3+ from aqueous solutions has been investigated. Results showed that both samples prefer to remove Pb2+ instead of Cr3+. Almost 100% of Pb2+ was removed from solutions with concentration until 50 mg L-1 and 100 mg L-1 of this metal, respectively by dacite and zeolite. The equilibrium of metals adsorption process was reached during the first 30 min by both materials. Na+ can be used to recover Pb2+, but not to remove Cr3+ from the treated samples. The Sips model showed a good fit for experimental data of this study.

  4. The effects of zeolite molecular sieve based surface treatments on the properties of wool fabrics

    Energy Technology Data Exchange (ETDEWEB)

    Carran, Richard S.; Ghosh, Arun, E-mail: Arun.Ghosh@agresearch.co.nz; Dyer, Jolon M.

    2013-12-15

    Wool is a natural composite fiber, with keratin and keratin-associated proteins as the key molecular components. The outermost surface of wool fibers comprises a hydrophobic lipid layer that can lead to unsatisfactory processing and properties of fabric products. In this study, molecular sieve 5A, a Na{sup +} and Ca{sup 2+} exchanged type A zeolite with a 1:1 Si:Al ratio was integrated onto the surface of wool using 3-mercaptopropyl trimethoxy silane. The resultant surface morphology, hydrophilicity and mechanical performance of the treated wool fabrics were then evaluated. Notably, the surface hydrophilicity of wool was observed to increase dramatically. When wool was treated with a dispersion of 2 wt% acetic acid, 2.5 wt% zeolite and 0.3 wt% or more silane, the water contact angle was observed to decrease from an average value of 148° to 0° over a period of approximately 30 s. Scanning electron microscopic imaging indicated good coverage of the wool surface with zeolite particles, with infrared spectroscopic evaluation indicating strong bonding of the dealuminated zeolite to wool keratins. This application of zeolite showed no adverse effects on the tensile and other mechanical properties of the fabric. This study indicates that zeolite-based treatment is a potentially efficient approach to increasing the surface hydrophilicity and modifying other key surface properties of wool and wool fabrics.

  5. The effects of zeolite molecular sieve based surface treatments on the properties of wool fabrics

    Science.gov (United States)

    Carran, Richard S.; Ghosh, Arun; Dyer, Jolon M.

    2013-12-01

    Wool is a natural composite fiber, with keratin and keratin-associated proteins as the key molecular components. The outermost surface of wool fibers comprises a hydrophobic lipid layer that can lead to unsatisfactory processing and properties of fabric products. In this study, molecular sieve 5A, a Na+ and Ca2+ exchanged type A zeolite with a 1:1 Si:Al ratio was integrated onto the surface of wool using 3-mercaptopropyl trimethoxy silane. The resultant surface morphology, hydrophilicity and mechanical performance of the treated wool fabrics were then evaluated. Notably, the surface hydrophilicity of wool was observed to increase dramatically. When wool was treated with a dispersion of 2 wt% acetic acid, 2.5 wt% zeolite and 0.3 wt% or more silane, the water contact angle was observed to decrease from an average value of 148° to 0° over a period of approximately 30 s. Scanning electron microscopic imaging indicated good coverage of the wool surface with zeolite particles, with infrared spectroscopic evaluation indicating strong bonding of the dealuminated zeolite to wool keratins. This application of zeolite showed no adverse effects on the tensile and other mechanical properties of the fabric. This study indicates that zeolite-based treatment is a potentially efficient approach to increasing the surface hydrophilicity and modifying other key surface properties of wool and wool fabrics.

  6. Effect of zeolite on the nitrogen fertilizer efficiency in rice crop

    International Nuclear Information System (INIS)

    Villareal-Nunez, Jose Ezequiel; Barahona-Amores, Luis Alberto; Castillo-Ortiz, Ovidio Antonio

    2015-01-01

    The objective of this work was to evaluate the effect of zeolite on the efficiency of nitrogen fertilizer in rice crop. The experiment was conducted in Cacao, Tonosi, Los Santos, Panama, between August and December 2012 and 2013 under rainfed conditions. The rice variety used was IDIAP FL 106-11 with seeding density of 110 kg/ha in a medium- fertility vertic Fluvisol. This study consisted of five treatments with four replications, following a completely randomized block design using N rate of 80 kg/ha mixed with different percentages of zeolite (0; 15; 25; 35 and 45%). The isotopic technique 15 N 3% excess to determine the nitrogen fertilizer use efficiency (EUNF) was used. Each experimental unit consist of 15 m 2 with three micro-plots of 1 m 2 where 15 N-labeled urea was applied at different times of the crop cycle to determine EUNF in each application. Top grain yields were obtained with 80 kg N + 45% zeolite/ha and 80 kg N + 15% zeolite/ha. A 7% EUNF increase was achieved with the addition of natural zeolite. Small doses of 12 kg/ha (15%) of zeolite can improve EUNF; after subsequent experiments, it is recommended to reduce the amount of N applied in soils with similar soil and climatic conditions suitable for growing rice. (author) [es

  7. Revealing Lattice Expansion of Small-Pore Zeolite Catalysts during the Methanol-to-Olefins Process Using Combined Operando X-ray Diffraction and UV-vis Spectroscopy.

    Science.gov (United States)

    Goetze, Joris; Yarulina, Irina; Gascon, Jorge; Kapteijn, Freek; Weckhuysen, Bert M

    2018-03-02

    In small-pore zeolite catalysts, where the size of the pores is limited by eight-ring windows, aromatic hydrocarbon pool molecules that are formed inside the zeolite during the Methanol-to-Olefins (MTO) process cannot exit the pores and are retained inside the catalyst. Hydrocarbon species whose size is comparable to the size of the zeolite cage can cause the zeolite lattice to expand during the MTO process. In this work, the formation of retained hydrocarbon pool species during MTO at a reaction temperature of 400 °C was followed using operando UV-vis spectroscopy. During the same experiment, using operando X-ray Diffraction (XRD), the expansion of the zeolite framework was assessed, and the activity of the catalyst was measured using online gas chromatography (GC). Three different small-pore zeolite frameworks, i.e., CHA, DDR, and LEV, were compared. It was shown using operando XRD that the formation of retained aromatic species causes the zeolite lattice of all three frameworks to expand. Because of the differences in the zeolite framework dimensions, the nature of the retained hydrocarbons as measured by operando UV-vis spectroscopy is different for each of the three zeolite frameworks. Consequently, the magnitude and direction of the zeolite lattice expansion as measured by operando XRD also depends on the specific combination of the hydrocarbon species and the zeolite framework. The catalyst with the CHA framework, i.e., H-SSZ-13, showed the biggest expansion: 0.9% in the direction along the c -axis of the zeolite lattice. For all three zeolite frameworks, based on the combination of operando XRD and operando UV-vis spectroscopy, the hydrocarbon species that are likely to cause the expansion of the zeolite cages are presented; methylated naphthalene and pyrene in CHA, 1-methylnaphthalene and phenalene in DDR, and methylated benzene and naphthalene in LEV. Filling of the zeolite cages and, as a consequence, the zeolite lattice expansion causes the

  8. Revealing Lattice Expansion of Small-Pore Zeolite Catalysts during the Methanol-to-Olefins Process Using Combined Operando X-ray Diffraction and UV–vis Spectroscopy

    KAUST Repository

    Goetze, Joris

    2018-02-06

    In small-pore zeolite catalysts, where the size of the pores is limited by eight-ring windows, aromatic hydrocarbon pool molecules that are formed inside the zeolite during the Methanol-to-Olefins (MTO) process cannot exit the pores and are retained inside the catalyst. Hydrocarbon species whose size is comparable to the size of the zeolite cage can cause the zeolite lattice to expand during the MTO process. In this work, the formation of retained hydrocarbon pool species during MTO at a reaction temperature of 400 °C was followed using operando UV–vis spectroscopy. During the same experiment, using operando X-ray Diffraction (XRD), the expansion of the zeolite framework was assessed, and the activity of the catalyst was measured using online gas chromatography (GC). Three different small-pore zeolite frameworks, i.e., CHA, DDR, and LEV, were compared. It was shown using operando XRD that the formation of retained aromatic species causes the zeolite lattice of all three frameworks to expand. Because of the differences in the zeolite framework dimensions, the nature of the retained hydrocarbons as measured by operando UV–vis spectroscopy is different for each of the three zeolite frameworks. Consequently, the magnitude and direction of the zeolite lattice expansion as measured by operando XRD also depends on the specific combination of the hydrocarbon species and the zeolite framework. The catalyst with the CHA framework, i.e., H-SSZ-13, showed the biggest expansion: 0.9% in the direction along the c-axis of the zeolite lattice. For all three zeolite frameworks, based on the combination of operando XRD and operando UV–vis spectroscopy, the hydrocarbon species that are likely to cause the expansion of the zeolite cages are presented; methylated naphthalene and pyrene in CHA, 1-methylnaphthalene and phenalene in DDR, and methylated benzene and naphthalene in LEV. Filling of the zeolite cages and, as a consequence, the zeolite lattice expansion causes the

  9. Revealing Lattice Expansion of Small-Pore Zeolite Catalysts during the Methanol-to-Olefins Process Using Combined Operando X-ray Diffraction and UV–vis Spectroscopy

    Science.gov (United States)

    2018-01-01

    In small-pore zeolite catalysts, where the size of the pores is limited by eight-ring windows, aromatic hydrocarbon pool molecules that are formed inside the zeolite during the Methanol-to-Olefins (MTO) process cannot exit the pores and are retained inside the catalyst. Hydrocarbon species whose size is comparable to the size of the zeolite cage can cause the zeolite lattice to expand during the MTO process. In this work, the formation of retained hydrocarbon pool species during MTO at a reaction temperature of 400 °C was followed using operando UV–vis spectroscopy. During the same experiment, using operando X-ray Diffraction (XRD), the expansion of the zeolite framework was assessed, and the activity of the catalyst was measured using online gas chromatography (GC). Three different small-pore zeolite frameworks, i.e., CHA, DDR, and LEV, were compared. It was shown using operando XRD that the formation of retained aromatic species causes the zeolite lattice of all three frameworks to expand. Because of the differences in the zeolite framework dimensions, the nature of the retained hydrocarbons as measured by operando UV–vis spectroscopy is different for each of the three zeolite frameworks. Consequently, the magnitude and direction of the zeolite lattice expansion as measured by operando XRD also depends on the specific combination of the hydrocarbon species and the zeolite framework. The catalyst with the CHA framework, i.e., H-SSZ-13, showed the biggest expansion: 0.9% in the direction along the c-axis of the zeolite lattice. For all three zeolite frameworks, based on the combination of operando XRD and operando UV–vis spectroscopy, the hydrocarbon species that are likely to cause the expansion of the zeolite cages are presented; methylated naphthalene and pyrene in CHA, 1-methylnaphthalene and phenalene in DDR, and methylated benzene and naphthalene in LEV. Filling of the zeolite cages and, as a consequence, the zeolite lattice expansion causes the

  10. Penggunaan Zeolit Sebagai Media Penyaring Pada Pengolahan Air LimbahDomestik

    Directory of Open Access Journals (Sweden)

    Yanto Yanto

    2011-02-01

    Full Text Available Sand filter is frequentlyused to treat contaminated water. Channel filter system is a modification of sand filter where the channel is shaped thus the land requirement could be minimized, water is flowed horizontallyfrom intial tank to finaltank through sand filter. Employing the channel filter to treat domestic wastewateris capable of reducing E. Coli up to 98.14%, increasing DO up to 27% and decreasing BOD5 up to 27%. Unfortunately, the final content of E.Coli after treatment process completed is still unacceptable for drinking water. Several options are available to improve the performance of the channel filter system. One of the promising alternativesis modifying the filter medium. Zeolite is natural material that has been utilized to improvewater quality based on several parameters such as Fe, Mn, organic materials, CO and others. Application of zeolite to diminish E. Coli is a challenge. This paper will investigate the effectiveness of zeolite to lower E. Coli contained in domestic wastewater . Zeolite was added to sand filter where thefraction of zeolite is about 5%. Two kind of zeolite-sand combination was implemented that is arranged and mixed zeolite-sand. Wastewater containing E.Coli was then put in the initial tank. Through the hole createdin the tank, wastewater then flowed passing through the combined zeolite-sand filter and accumulated in the final tank. Both E. Coli from initial and final tank was measured to compute treatment efficiency. The result showsE. Coli decreases up to99.99%, BOD5and DO decrease more than 71% and 66% respectively. It can be concluded that 5% addition ofzeolite is able to improve treatment efficiency ofsand filter.

  11. Influence of Nutrient Impregnated into Zeolite Addition on Anaerobic Digestion of Palm Oil Mill Effluent (POME)

    Science.gov (United States)

    Mellyanawaty, M.; Chusna, F. M. A.; Sudibyo, H.; Nurjanah, N.; Budhijanto, W.

    2018-03-01

    Palm oil mill effluent (POME) was wastewater generated from palm oil milling activities which was brownish liquid, acidic with pH 3-4, and contained soluble materials which were hazardous to the environment. It was characterized by high organic loading (COD 40,000–60,000 mg/L). According to its characteristics, POME was identified as a potential source to generate renewable energy through anaerobic digestion. In other words, a combination of wastewater treatment and renewable energy production would be an additional advantage to the palm oil industries. Methanogenesis was the rate limiting step in anaerobic digestion. In the conventional anaerobic digester, it required large reactors and long retention time. The addition of microbial immobilization media was to improve anaerobic reactor performance in term of higher organic removal and methane production. Additionally, better performance could lead to reduction of reactor volume and shorter retention time in high rate anaerobic digester. The loading of essential microorganism nutrient into the media might increase the affinity of bacteria to attach and grow on the media surface. Activating or inhibition effects of natural and modified zeolite addition in anaerobic digestion of POME was studied in batch reactors using erlenmeyer of 1,000 mL at COD concentrations of about 8,000 mg/L. Zeolite was impregnated with nickel and magnesium at concentrations of 0.0561 mg Ni/g zeolite and 0.0108 mg Mg/g zeolite. The effect of the different zeolite addition was determined by the measurement of soluble COD (sCOD), Volatile Fatty Acids (VFAs) and biogas production. Greater effect of modified zeolite was observed in zeolite impregnated with nickel with a 54% increase of biogas production. Meanwhile, the modified zeolite impregnated with magnesium had no positive impact to the methanogenic bacteria activities.

  12. Mesoporous zeolite single crystal catalysts: Diffusion and catalysis in hierarchical zeolites

    DEFF Research Database (Denmark)

    Christensen, Christina Hviid; Johannsen, Kim; Toernqvist, Eric

    2007-01-01

    in the zeolite micropores. Here, we briefly discuss the most important ways of introducing mesopores into zeolites and, for the first time, we show experimentally that the presence of mesopores dramatically increases the rate of diffusion in zeolite catalysts. This is done by studying the elution of iso-butane...... from packed beds of conventional and mesoporous zeolite catalysts. Moreover, we discuss in detail the recent observation of improved activity and selectivity in the alkylation of benzene with ethene using mesoporous zeolite single crystal catalysts. For this reaction, we show by calculation...

  13. Study of the ortho-positron annihilation process in zeolite Y

    International Nuclear Information System (INIS)

    Alvarado D, M. E.

    2010-01-01

    For several years a great interest has existed for the study of the natural and synthetic zeolites due to its properties. The porosity, one of their main characteristics allows that these materials are used as molecular sieves, catalysts, gases drying, etc. In order to investigating the porosity and other zeolite properties one carries out the study of the process of positron annihilation lifetime spectroscopy (Pals). This is a technique that provides information about the size and the pores form since is highly sensitive to the free volume and the superficial area of those porous materials as the zeolites. The study began with the elaboration of zeolite Y tablets in a hydraulic press where different pressures (from 0 to 1.26 GPa) and masses (70, 80 and 100 mg) were proven to obtain the estimate porosity of each tablet. A graph was elaborated and the effect of the mass and pressure with regard to the zeolite porosity was analyzed. Later on, the powder and tablets of 70 mg were characterized by means of X-ray diffraction (the glass size, interplanar distance, length and the volume of the unitary cell); scanning electron microscopy (the particles size and morphology); thermo gravimetric analysis (dehydration temperature and the stability up to 700 C) and the Brunauer Emmett Teller method (specific area). After the zeolite Y tablets characterization was carried out the positron annihilation process by means of Pals where its free volume of zeolite Y was analyzed, which includes to the structural cavities and the interparticle volume. The powdered zeolite was analyzed to different experimental conditions (preparation of the sample and the Pals equipment) to obtain the optimal conditions (a window with a time of 400 ns and a enlarged energy window) of analysis. On the other hand, the tablets were analyzed under optimal conditions to obtain the four components of time and intensity (τ, Ι), result of the different ways of positrons annihilation in the zeolite. These

  14. Removal of uranium from water media by bentonite and zeolite

    International Nuclear Information System (INIS)

    Viglasova, E.; Krajnak, A.; Galambos, M.; Rosskopfova, O.

    2014-01-01

    The removal and recovery of uranium from contaminated surface, environment and ground water, as result of nuclear industries, has attracted more and more attentions. Several methods are available for removing of uranium, but adsorption among the others, is the most attractive. In case of management of radioactive waste, the adsorption of radionuclides plays significant role. Among the natural sorbents applied to the adsorption of uranium zeolites and bentonites offer a number of advantages. The main aims of this work are investigations of adsorption properties of Greek zeolite Metaxades and Greek bentonite Kimolos during adsorption of uranium from water solutions, comparison of their adsorption characteristics, fitting with isotherms (Freundlich, Langmuir and DR isotherm) and its behaviour during kinetics process influenced by temperature. (authors)

  15. Selective adsorption of bacterial cells onto zeolites.

    Science.gov (United States)

    Kubota, Munehiro; Nakabayashi, Tadashi; Matsumoto, Yuki; Shiomi, Tohru; Yamada, Yusuke; Ino, Keita; Yamanokuchi, Hiroyuki; Matsui, Masayoshi; Tsunoda, Tatsuo; Mizukami, Fujio; Sakaguchi, Kengo

    2008-06-15

    Zeolites adsorb microbial cells on their surfaces and selective adsorption for specific microorganisms was seen with certain zeolites. Tests for the adsorption ability of zeolites were conducted using various established microbial cell lines. Specific cell lines were shown to selectively absorb to certain zeolites, species to species. In order to understand the selectivity of adsorption, we tested adsorption under various pH conditions and determined the zeta-potentials of zeolites and cells. The adsorption of some cell lines depended on the pH, and some microorganisms were preferentially adsorbed at acidic pH. The values of zeta-potentials were used for calculating the electric double layer interaction energy between zeolites and microbial cells. There was a correlation between the experimental adsorption results and the interaction energy. Moreover, we evaluated the surface hydrophobicity of bacterial cells by using the microbial adherence to hydrocarbon (MATH) assay. In addition, we also applied this method for zeolites to quantify relative surface hydrophobicity. As a result, we found a correlation between the adsorption results and the hydrophobicity of bacterial cells and zeolites. These results suggested that adsorption could be explained mainly by electric double layer interactions and hydrophobic interactions. Finally, by using the zeolites Na-BEA and H-Y, we succeeded in clearly separating three representative microbes from a mixture of Escherichia coli, Bacillus subtilis and Staphylococcus aureus. Zeolites could adsorb each of the bacterial cell species with high selectivity even from a mixed suspension. Zeolites can therefore be used as effective carrier materials to provide an easy, rapid and accurate method for cell separation.

  16. Removal of Cu 2+ Ions from Aqueous Medium Using Clinoptilolite/Emeraldine Base Composite

    Directory of Open Access Journals (Sweden)

    Silviya I. Lavrova

    2016-12-01

    Full Text Available The aim of this study was to investigate the removal efficiency of in situ synthesized composites consisted of emeraldine base and clinoptilolite on copper ions removal from aqueous medium. Two composite materials (Composite I and Composite II with different quantity of clinoptilolite were synthesised. The influence of the composite dosage, the contact time and the initial copper ions concentration has been studied. The results show that the significant removal of the copper ions becomes at the first minute of the contact between the composite material and the aqueous medium and the longer contact time leads to increasing of the copper ions removal. The removal efficiency at the 1st minute was 57.5% and 77.3% using Composite Iand Composite II, respectively. Maximum removal efficiency of 87.3% and 96.8% was achieved at the same dosage of Composite I and Composite II, respectively, at contact time of 360 minutes and temperature of 24 °C.

  17. Performance of skid resistance of warm-mix asphalt with buton natural asphalt-rubber (BNA-R) and zeolite additives as a result of road surface temperature changes

    Science.gov (United States)

    Anagi, Natasha; Hadiwardoyo, Sigit Pranowo; Sumabrata, R. Jachrizal; Wahjuningsih, Nurul

    2017-06-01

    Roughness of the road surface acts as an obstacle for the vehicle wheel slip on the road surface especially in wet conditions. Road surface roughness can be generated from the properties of the aggregate or bitumen as a characteristic of asphalt mixture. Various types of added material have been used to improve the performance of hot mix asphalt mixture as well as the warm mix asphalt. The addition of BNA-R and zeolite on the warm asphalt mixtures has been investigated, particularly related with its effect on the value of the skid surface due to the wheels track of the vehicle. The study was conducted in an asphalt mixture before and after the traversed wheel condition. In this study, 7.560 trajectory path using the Wheel Tracking Machine and skid resistance test using a modified British Pendulum Tester, were conducted. Skid resistance test involved various temperatures on the surface of the specimen. The results showed that the addition of BNA-R can increase the value of the skid at the beginning of the track, but at the last track, skid resistance performance was stagnant. Zeolite additive material in warm mix asphalt has improved skid resistance, especially the resistance of asphalt concrete mixture to temperature changes.

  18. Zeolite from fly ash: synthesis and characterization

    Indian Academy of Sciences (India)

    Coal fly ash was used to synthesize X-type zeolite by alkali fusion followed by hydrothermal treatment. The synthesized zeolite was characterized using various techniques such as X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, BET method for surface area measurement etc.

  19. Zeolite from fly ash: synthesis and characterization

    Indian Academy of Sciences (India)

    Unknown

    disposal or to minimize the environmental impact. One of the approaches is the conversion of fly ash to zeolites, which have wide applications in ion exchange, as mole- cular sieves, catalysts, and adsorbents (Breck 1974). The present study is concerned with the synthesis of zeolite from coal fly ash and its characterization ...

  20. Synthesis of LTA zeolite for bacterial adhesion

    Directory of Open Access Journals (Sweden)

    Raja Belaabed

    2016-07-01

    X-ray diffraction, environmental scanning electron microscope and attenuated total reflection-Fourier transform infrared spectroscopy were used to characterize the synthesized zeolite. To evaluate the bacterial adhesion to zeolite LTA the hydrophobicity and surface properties are examined using contact angle measurement.

  1. Exfoliation of two-dimensional zeolites in liquid polybutadienes

    KAUST Repository

    Sabnis, Sanket

    2017-06-16

    Layered zeolite precursors were successfully exfoliated by brief shearing or sonication with the assistance of commercially available telechelic liquid polybutadienes at room temperature. The exfoliated zeolite nanosheets can form a stable suspension in an organic solvent, providing exciting potential for the fabrication of zeolite membranes, composite materials and hierarchical zeolites.

  2. Zeolites for nitrosamine and pharmaceutical removal from demineralised and surface water: Mechanisms and efficacy

    KAUST Repository

    De Ridder, David J.

    2012-03-01

    Zeolites with a high Si/Al ratio can be used as selective adsorbents in water treatment, targeting organic micropollutants which are removed poorly with activated carbon. Due to size exclusion, many Natural Organic Matter (NOM) components cannot access the pores, thus limiting adsorption competition between organic micropollutant and NOM. Furthermore, zeolite channel diameters are close to molecule diameters, which results in strong van der Waals interaction. MOR200 and ZSM5, the two most hydrophobic zeolites, showed the highest removal of neutral nitrosamines in demineralised water, with higher efficacy than activated carbon. DAY and MOR30, which were relatively hydrophilic zeolites, did not show appreciable removal of any of the nitrosamines. When nitrosamines were adsorbed from surface water, there was no influence of competition with, or pore blockage by, NOM components on nitrosamine removal for ZSM5 zeolite, in contrast to activated carbon. Repulsion of negatively charged pharmaceuticals was significant for ZSM5, which had a Si/Al ratio of 80. MOR200 had a Si/Al ratio of 200, indicating a lower Al content than ZSM5 and, as such, a lower negative surface charge. Charge effects were not observed for MOR200. A relationship was found between the Stokes diameter of the pharmaceuticals and nitrosamines, and their removal by ZSM5 and MOR200, indicating that a "close fit" adsorption mechanism is more likely than hydrophobic interaction in these zeolites. Due to their selective nature, adsorption on zeolites should only be considered as an additional treatment step to existing processes, dedicated for the removal of specific organic micropollutants. Less specific treatment techniques, such as activated carbon filtration, are still required to ensure a broad barrier for organic micropollutants in water treatment. © 2012 Elsevier B.V. All rights reserved.

  3. Zeolitic materials with hierarchical porous structures.

    Science.gov (United States)

    Lopez-Orozco, Sofia; Inayat, Amer; Schwab, Andreas; Selvam, Thangaraj; Schwieger, Wilhelm

    2011-06-17

    During the past several years, different kinds of hierarchical structured zeolitic materials have been synthesized due to their highly attractive properties, such as superior mass/heat transfer characteristics, lower restriction of the diffusion of reactants in the mesopores, and low pressure drop. Our contribution provides general information regarding types and preparation methods of hierarchical zeolitic materials and their relative advantages and disadvantages. Thereafter, recent advances in the preparation and characterization of hierarchical zeolitic structures within the crystallites by post-synthetic treatment methods, such as dealumination or desilication; and structured devices by in situ and ex situ zeolite coatings on open-cellular ceramic foams as (non-reactive as well as reactive) supports are highlighted. Specific advantages of using hierarchical zeolitic catalysts/structures in selected catalytic reactions, such as benzene to phenol (BTOP) and methanol to olefins (MTO) are presented. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Proton Adsorption Selectivity of Zeolites in Aqueous Media: Effect of Si/Al Ratio of Zeolites

    Directory of Open Access Journals (Sweden)

    Moses Wazingwa Munthali

    2014-12-01

    Full Text Available In addition to their well-known uses as catalysts, zeolites are utilized to adsorb and remove various cations from aqueous system. The adsorption of the cations is ascribed to the negative charge of zeolites derived from isomorphous substitution of Si by Al. The amount of Na+ adsorption on 4A, X, Y, Na-P1 and mordenite type zeolites were determined in aqueous media, in a two-cation (Na+ and H+ system. Although each zeolite has a constant amount of negative charge, the amount of Na+ adsorption of each zeolite decreased drastically at low pH−pNa values, where pH−pNa is equal to log{(Na+/(H+}. By using the plot of the amount of Na+ adsorption versus pH−pNa, an index of the H+ selectivity, which is similar to the pKa of acids, of each zeolite was estimated, and the index tended to increase with decreasing Si/Al ratio of zeolites. These indicate that zeolites with lower Si/Al and higher negative charge density have higher H+ adsorption selectivity, and in fact, such a zeolite species (4A and X adsorbed considerable amount of H+ even at weakly alkaline pH region. The adsorption of H+ results in the decrease of cation adsorption ability, and may lead to the dissolution of zeolites in aqueous media.

  5. Investigation of the adsorption of water vapor and carbon dioxide by KA zeolite

    International Nuclear Information System (INIS)

    Khanitonov, V.P.; Shtein, A.S.

    1984-01-01

    According to the present data, KA zeolite, which can adsorb only water vapor, helium, and hydrogen, has the greatest selectivity in drying. The feasibility of using this zeolite in devices for selective drying of gases used in gas-analysis systems was studied. The results of the experiments were approximated by the thermal equation of the theory of bulk filling of micropores. The limiting value of the adsorption depends on the temperature, and it can be calculated according to the density of the adsorbed phase and the adsorption volume. The critical diameters of the water and carbon dioxide molecules are close to the dimensions of the KA-zeolite pores, something that determines the activated nature of the adsorption of these substances. Experiments on coadsorption of water vapor and carbon dioxide by a fixed bed of KA-zeolite under dynamic conditions showed that the adsorption of these substances has a frontal nature. The time of the protective action of the layer of zeolite during adsorption af water vapor exceeded by more than an order the time of the protective action during adsorption of carbon dioxide. The results showed that this adsorbent can be used for selective drying of gas mixtures containing carbon dioxide in batch-operation devices. Beforehand, the adsorbent should be regenerated with respect to moisture, and then it should be saturated with carbon dioxide by blowing the adsorbent with a gas mixture of the working composition until the equilibrium state is reached

  6. Zeolites on Mars: Possible environmental indicators in soils and sediments

    International Nuclear Information System (INIS)

    Ming, D.W.; Gooding, J.L.

    1988-01-01

    Weathering products should serve as indicators of weathering environments and may provide the best evidence of the nature of climate change on Mars. No direct mineralogical measurements of Martian regolith were performed by the Viking missions, but the biology and X-ray fluorescence experiments provided some information on the physiochemical properties of Martian regolith. Most post-Viking studies of candidate weathering products have emphasized phyllosilicates and Fe-oxides; zeolites are potentially important, but overlooked, candidate Martian minerals. Zeolites would be important on Mars for three different reasons. First, they are major sinks of atmospheric gases and, per unit mass, are stronger and more efficient sorbents than are phyllosilicates. Secondly, they can be virtually unique sorbents and shelters for organic compounds and possible catalysts for organic-based reactions. Finally, their exchangeable ions are good indicators of the chemical properties of solutions with which they have communicated. Accordingly, the search for information on past compositions of the Martian atmosphere and hydrosphere should find zeolites to be rich repositories

  7. Water nanodroplets confined in zeolite pores.

    Science.gov (United States)

    Coudert, François-Xavier; Cailliez, Fabien; Vuilleumier, Rodolphe; Fuchs, Alain H; Boutin, Anne

    2009-01-01

    We provide a comprehensive depiction of the behaviour of a nanodroplet of approximately equal to 20 water molecules confined in the pores of a series of 3D-connected isostructural zeolites with varying acidity, by means of molecular simulations. Both grand canonical Monte Carlo simulations using classical interatomic forcefields and first-principles Car-Parrinello molecular dynamics were used in order to characterise the behaviour of confined water by computing a range of properties, from thermodynamic quantities to electronic properties such as dipole moment, including structural and dynamical information. From the thermodynamic point of view, we have identified the all-silica zeolite as hydrophobic, and the cationic zeolites as hydrophilic; the condensation transition in the first case was demonstrated to be of first order. Furthermore, in-depth analysis of the dynamical and electronic properties of water showed that water in the hydrophobic zeolite behaves as a nanodroplet trying to close its hydrogen-bond network onto itself, with a few short-lived dangling OH groups, while water in hydrophilic zeolites "opens up" to form weak hydrogen bonds with the zeolite oxygen atoms. Finally, the dipole moment of confined water is studied and the contributions of water self-polarisation and the zeolite electric field are discussed.

  8. Increased photocatalytic activity of Zn(II)/Cu(II) oxides and sulfides by coupling and supporting them onto clinoptilolite nanoparticles in the degradation of benzophenone aqueous solution.

    Science.gov (United States)

    Esmaili-Hafshejani, Javad; Nezamzadeh-Ejhieh, Alireza

    2016-10-05

    Photocatalytic activity of the coupled ZnO-CuO and ZnS-CuS semiconductors supported onto clinoptilolite nanoparticles (CNP) and micronized one (CMP) was studied in photodegradation of benzophenone (BP) aqueous solution. The ZnO-CuO/CNP (or MCP) and ZnS-CuS/CNP (or MCP) catalysts were prepared via calcination and sulfiding of their Zn(II)-Cu(II) ion-exchanged samples, respectively. XRD patterns confirmed loading of the mentioned semiconductors onto the zeolite, and nano dimension of the catalysts was confirmed by XRD and TEM results. Typical Tauc plots obtained from UV-vis DRS spectra showed red shifts for the band gap energies of the supported coupled semiconductors with respect to the supported monocomponent ones especially for ZnO/NCP and ZnS/NCP catalysts. Also, in both indirect and direct transitions, these red shifts were more considerable in the oxidic systems with respect to the sulfidic systems. Accordingly, the supported oxidic systems showed better photocatalytic activity than the sulfidic one. In the oxidic systems changing the dose of CuO played important role while in the sulfidic systems ZnS played considerable role in the degradation of BP. In the used systems, CuO and ZnS played the main e/h generators in the oxidic and sulfidic systems, respectively, while ZnO and CuS played the preventer e/h recombination. Based on the results, production of e/h is the rate limiting step in the used systems. The maximum degradation activity of the catalysts was obtained at: 0.12gL(-1) of ZnO0.80-CuO3.18/NCP and 0.10gL(-1) of ZnS1.39-CuS2.88/NCP catalysts, initial BP concentration of 30mgL(-1) at pH 7.5. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. The role of zeolite in the Fischer–Tropsch synthesis over cobalt–zeolite catalysts

    International Nuclear Information System (INIS)

    Sineva, L V; Mordkovich, V Z; Asalieva, E Yu

    2015-01-01

    The review deals with the specifics of the Fischer–Tropsch synthesis for the one-stage syncrude production from CO and H 2 in the presence of cobalt–zeolite catalytic systems. Different types of bifunctional catalysts (hybrid, composite) combining a Fischer–Tropsch catalyst and zeolite are reviewed. Special attention focuses on the mechanisms of transformations of hydrocarbons produced in the Fischer–Tropsch process on zeolite acid sites under the synthesis conditions. The bibliography includes 142 references

  10. Synthesis of K2O/Zeolite catalysts by KOH impregnation for biodiesel production from waste frying oil

    Science.gov (United States)

    Fitriana, N.; Husin, H.; Yanti, D.; Pontas, K.; Alam, P. N.; Ridho, M.; Iskandar

    2018-03-01

    K2O/Zeolite compounds were successfully synthesized using KOH as starting material and natural zeolite as support. The catalysts were calcined at 500°C for 3 h and then characterized by X-Ray Diffractometer (XRD) and Scanning Electron Microscopy (SEM). The SEM images reveal that the zeolite and K2O/zeolite particles are irregular in shape (100 to 400 nm). The independent variables were impregnated amounts of KOH (15 - 25%), catalyst to oil ratios of 1.0 - 6.0 wt.%, and reaction time of 2 h. The highest biodiesel yield of 95% was produced from the reaction with 2.1 wt.% catalyst of 25% KOH impregnated. The properties of produced biodiesel complied with SNI. The catalytic stability test showed that the 25% KOH impregnated catalyst was stable.

  11. A general method to incorporate metal nanoparticles in zeolites and zeotypes

    DEFF Research Database (Denmark)

    2015-01-01

    Disclosed herein is a method for producing a zeolite, zeolite-like or zeotype structure with selective formation of metal, metal oxide or metal sulphide nanoparticles and/or clusters inside the zeolite, zeolite-like or zeotype structure.......Disclosed herein is a method for producing a zeolite, zeolite-like or zeotype structure with selective formation of metal, metal oxide or metal sulphide nanoparticles and/or clusters inside the zeolite, zeolite-like or zeotype structure....

  12. Metal-Exchanged β Zeolites as Catalysts for the Conversion of Acetone to Hydrocarbons

    Directory of Open Access Journals (Sweden)

    Aurora J. Cruz-Cabeza

    2012-01-01

    Full Text Available Various metal-β zeolites have been synthesized under similar ion-exchange conditions. During the exchange process, the nature and acid strength of the used cations modified the composition and textural properties as well as the Brönsted and Lewis acidity of the final materials. Zeolites exchanged with divalent cations showed a clear decrease of their surface Brönsted acidity and an increase of their Lewis acidity. All materials were active as catalysts for the transformation of acetone into hydrocarbons. Although the protonic zeolite was the most active in the acetone conversion (96.8% conversion, the metal-exchanged zeolites showed varied selectivities towards different products of the reaction. In particular, we found the Cu-β to have a considerable selectivity towards the production of isobutene from acetone (over 31% yield compared to 7.5% of the protonic zeolite. We propose different reactions mechanisms in order to explain the final product distributions.

  13. EFFECTS OF ZEOLITE AND CADMIUM ON GROWTH AND CHEMICAL COMPOSITION OF SOYBEAN (Glycine max L.

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Mahmoodabadi

    2009-04-01

    Full Text Available   There are areas in the world which are polluted by trace metals some of which may not be degraded by biotic process. Some of these metals might enter into surface and/or underground water resources thus causing serious human and animal health problems. In recent years, natural amendments, such as the use of zeolite, have been widely used to address trace metals contamination. In the present study the effect of zeolite on the growth and nodulation of soybean (Glycine max L. was evaluated. Treatments consisted on factorial combination of three levels of zeolite (0, 2 and 5 g kg-1 and three levels of cadmium (0, 10 and 50 mg kg-1. Cadmium application significantly decreased shoot and root dry weight while its concentration in plant parts was increased. In addition, cadmium application decreased number and dry weight of nodules, and N, K, and Mn concentrations. On the other hand, zeolite application markedly increased number and dry weight of nodules and N, P, K concentrations in shoot, Mn and Cu concentrations in shoot and root. The results from the present study can be used for predicting the efficiency of zeolite application for the remediation of contaminated soils.

  14. Penggunaan zeolit alam untuk mengurangi kandungan krom dan nh4+ dalam air limbah penyamakan kulit

    Directory of Open Access Journals (Sweden)

    Supraptiningsih Supraptiningsih

    2006-07-01

    Full Text Available Leather tanning waste water contains chemical compounds, such as chromium and NH4+ in high concentration, so if they are thrown away without treatment they will make some problems. The aims of this research is to adsorb the cations in leather tanning waste water i.e chromium and NH4+ used natural zeolite as an adsorbent. Research was done by comparing amount of chromium and NH4+ in effluent waste water treatment unit with amount of chromium and NH4+ after being adsorbed by zeolite in a batch system. The result of this research showed that efficiency difference between using zeolite and waste water treatment unit was significant. The optimal condition to reduce chromium and NH4+ was by using 300 grams per liter waste, zeolite particle size was 50-60 mesh, contact time was 24 hours and pH 8±0,1. In this condition, zeolites could reduce chromium from 3728,56mg/l to 365,39 mg/l or 90,20%, and NH4+ from 3040,02 mg/l menjadi 209,76 mg/l or 93,10%. Waste water treatment unit could reduce chromium 63,55% and NH4+ 56,75%.

  15. Oxygen exchange between C18O2 and ''acidic'' oxide and zeolite catalysts

    International Nuclear Information System (INIS)

    Peri, J.B.

    1975-01-01

    The exchange of oxygen between C 18 O 2 and several high-area oxides, including silica, γ-alumina, silica--alumina, and zeolite catalysts, was studied. Infrared spectra of adsorbed CO 2 and of surface ''carbonates'' were used to follow the rate of oxygen exchange and investigate the nature of unusually exchangeable surface oxide ions, present at low concentrations. Interaction of CO 2 with the surface typically produced initial exchange of one oxygen atom, as expected from interaction with a single oxide ion (CO 2 + O 2- reversible CO 3 2- ), and the number of exchangeable ions increased with increasing temperature. The rate of oxygen exchange did not correlate with chemisorption to form stable surface carbonates or with the extent of strong physical adsorption of CO 2 . With dry silica, exchange was insignificant below 600 0 ; with catalytically active zeolites and dry γ-alumina, it was detectable at 200 0 and fairly rapid at 300--400 0 . Silica--alumina required 100--150 0 higher temperature for exchange than did an active zeolite. Activity for cracking and other hydrocarbon reactions may be related to the ease of exchange of some surface oxide ions with CO 2 . Active zeolites have reactive oxide sites resembling those on dry γ-alumina, but such sites on zeolites are probably less-readily eliminated by chemisorption of H 2 O or other compounds. (U.S.)

  16. Effect of Australian zeolite on methane production and ammonium removal during anaerobic digestion of swine manure

    DEFF Research Database (Denmark)

    Wijesinghe, D. Thushari N.; Dassanayake, Kithsiri B.; Scales, Peter J.

    2018-01-01

    Anaerobic digestion is one of the most effective methods for treating swine manure by converting it into green energy, and efficiently reducing methane (CH4) emission to the atmosphere. Low C/N ratio of swine manure and the production of high levels of total ammoniacal nitrogen (TAN) during...... acidogenesis due to the high N contents of swine manure considerably reduce CH4 yield. The reduction of N during anaerobic digestion by the addition of zeolite improves CH4 production and reduces potential environmental threats associated with ammonia (NH3) emissions from anaerobic digestion of swine manure....... The main objective of this study was to determine the optimum Australian zeolite dose that produces maximum NH4 + recovery at optimum CH4 production. In laboratory experiments, swine manure was treated with natural and sodium zeolites at 0, 10, 40, 70, 100 mg/L and digested anaerobically for 60 days...

  17. Co and Cu ZSM-5 zeolites for the direct production of oxygenates from methane and oxygen

    NARCIS (Netherlands)

    Beznis, N.

    2010-01-01

    The direct partial oxidation of methane to oxygenates still remains one of the greatest challenges in catalysis. Metal-containing zeolites hold great potential for the direct partial oxidation of methane to oxygenates. The nature of the active sites in these materials is, however, still a matter of

  18. Vibrational properties of water molecules adsorbed in different zeolitic frameworks

    International Nuclear Information System (INIS)

    Crupi, V; Longo, F; Majolino, D; Venuti, V

    2006-01-01

    The perturbation of water 'sorbed' in samples of zeolites of different structural type, genesis, and cation composition (K-, Na-, Mg- and Ca-rich zeolites), namely the CHA framework of a synthetic K-chabazite, the LTA framework of synthetic Na-A and Mg50-A zeolites, and the NAT framework of a natural scolecite, has been studied by FTIR-ATR spectroscopy, in the -10 to +80 o C temperature range. The aim was to show how differences in the chemical composition and/or in the topology of the zeolite framework and, in particular, the possibility for the guest water molecules to develop guest-guest and/or host-guest interactions, lead to substantial differences in their vibrational dynamical properties. The spectra, collected in the O-H stretching and H 2 O bending mode regions, are complex, with multiple bands being observed. As far as water in the CHA and LTA frameworks is concerned, whose behaviour is governed by the balance of water-water, water-framework and water-extra-framework cations interactions, the assignment of the resolved components of the O-H stretching band has been discussed by fitting the band shapes into individual components attributed to H 2 O molecules engaged in different degrees of hydrogen bonding. A detailed quantitative picture of the connectivity pattern of water, as a function of temperature and according to the chemical and topological properties of the environment, is furnished. The H 2 O bending vibrational bands give additional information that perfectly agrees with the results obtained from the analysis of the O-H stretching spectral region. In the case of scolecite, a small-pored zeolite where water-water interactions are eliminated, the increased complexity observed in the infrared spectra in the O-H stretching and H 2 O bending regions was explained as due to the hydrogen bonding between the water molecules and the network, and also with the extra-framework cation. Furthermore, these observations have been correlated with the different

  19. Diagenetic Quartz Morphologies and Zeolite formation

    DEFF Research Database (Denmark)

    Kazerouni, Afsoon Moatari; Hansen, Rikke Weibel; Friis, Henrik

    sands in these wells all contain authigenic silica/quartz of various morphologies identified with a combination of traditional optical microscopy and scanning electron microscopy. Late Paleocene–early Eocene volcanic ash layers are recognized throughout most of the North Sea and also recorded from......, the precipitation of zeolite may later facilitate further quartz cementation, which might otherwise be retarded by the presence of disordered microquartz. The silica activity of pore fluids can influence zeolite precipitation.  Although zeolite formation is clearly related to volcanic ash, zeolite has also formed...... are abundant in some of associated shales; and 2) volcanic ash. The dissolution of biogenic silica may result in a rapid release of silica thereby promoting the formation of diagenetic opal/microquartz, but there may be a limited release of Al. A limited release of Al may result in precipitation of Si...

  20. Synthesis of LTA zeolite for bacterial adhesion

    Energy Technology Data Exchange (ETDEWEB)

    Belaabed, R.; Eabed, S.; Addaou, A.; Laajab, A.; Rodriguez, M.A.; Lahsini, A.

    2016-07-01

    High affinity and adhesion capacity for Gram-positive bacteria on minerals has been widely studied. In this work the adhesion of bacteria on synthesized zeolite has been studied. The Zeolite Linde Type A (LTA) has been synthesized using hydrothermal route using processing parameters to obtain low cost materials. For adhesion studies Staphylococcus aureus and Bacillus subtilis were used as Gram-positive bacteria, Escherichia coli and Pseudomonas aeruginosa are used as Gram-negative bacteria. X-ray diffraction, environmental scanning electron microscope and attenuated total reflection-Fourier transform infrared spectroscopy were used to characterize the synthesized zeolite. To evaluate the bacterial adhesion to zeolite LTA the hydrophobicity and surface properties are examined using contact angle measurement. (Author)

  1. Mixing of zeolite powders and molten salt

    International Nuclear Information System (INIS)

    Pereira, C.; Zyryanov, V.N.; Lewis, M.A.; Ackerman, J.P.

    1996-01-01

    Transuranics and fission products in a molten salt can be incorporated into zeolite A by an ion exchange process and by a batch mixing or blending process. The zeolite is then mixed with glass and consolidated into a monolithic waste form for geologic disposal. Both processes require mixing of zeolite powders with molten salt at elevated temperatures (>700 K). Complete occlusion of salt and a uniform distribution of chloride and fission products are desired for incorporation of the powders into the final waste form. The relative effectiveness of the blending process was studied over a series of temperature, time, and composition profiles. The major criteria for determining the effectiveness of the mixing operations were the level and uniformity of residual free salt in the mixtures. High operating temperatures (>775 K) improved salt occlusion. Reducing the chloride levels in the mixture to below 80% of the full salt capacity of the zeolite significantly reduced the free salt level in the final product

  2. Polymeric Graphitic Carbon Nitride Doped with CuO Dispersed on Dealuminated Clinoptilolite (CuO/HCP): Synthesis and Characterisation

    OpenAIRE

    Sanni, Saheed Olalekan; Idemudia, Omoruyi Gold

    2015-01-01

    CuO dispersed on dealuminated clinoptilolite (CuO/HCP) and further doped with polymeric graphitic carbon nitride (CuO/HCP-g-C3N4) was synthesized through 2 facile routes: precipitation method for CuO/HCP and impregnation through ultrasonication method for the hybrid composite material. The hybrid composite material crystalline phase, surface morphology, and structural and thermal properties were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-r...

  3. The electric conductivity of some forms of sintered synthetic zeolites

    International Nuclear Information System (INIS)

    Susic, M.; Petrovic, V.; Ristic, M.; Petranovic, N.

    1978-01-01

    Some forms of synthetic zeolites were sintered and their electric conductivity was measured. The conductivity was observed in correlation with the conductivity of non-sintered pressed samples. Also the change in microstructural constituents in the course of the process of sintering was observed with an optical microscope. It has been found that there is a considerable change in conductivity due to sintering as well as a change in the activation energy for conduction. Also the porosity is noticeably changed. A marked affect of the nature of counter ions on the electric conductivity is shown

  4. Zeolite membranes for efficient synthesis of biofuels

    OpenAIRE

    Sandström, Linda

    2009-01-01

    The greenhouse effect and the limited fossil oil resources have increased the demand of renewable fuels. Zeolite membranes have potential applications in numerous separation processes, and could be useful in the development of efficient processes for renewable fuel production. Methanol synthesis from synthesis gas is equilibrium limited, and continuous removal of products in a zeolite membrane reactor could improve the productivity of a conventional methanol synthesis process. In this work, m...

  5. Zeolitic catalytic conversion of alcohols to hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Narula, Chaitanya K.; Davison, Brian H.; Keller, Martin

    2018-04-10

    A method for converting an alcohol to a hydrocarbon, the method comprising contacting said alcohol with a metal-loaded zeolite catalyst at a temperature of at least 100.degree. C. and up to 550.degree. C., wherein said alcohol can be produced by a fermentation process, said metal is a positively-charged metal ion, and said metal-loaded zeolite catalyst is catalytically active for converting said alcohol to said hydrocarbon.

  6. Zeolitic catalytic conversion of alochols to hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Narula, Chaitanya K.; Davison, Brian H.; Keller, Martin

    2017-01-03

    A method for converting an alcohol to a hydrocarbon, the method comprising contacting said alcohol with a metal-loaded zeolite catalyst at a temperature of at least 100.degree. C. and up to 550.degree. C., wherein said alcohol can be produced by a fermentation process, said metal is a positively-charged metal ion, and said metal-loaded zeolite catalyst is catalytically active for converting said alcohol to said hydrocarbon.

  7. Synthesis and characterization of zeolite L

    International Nuclear Information System (INIS)

    Ko, Yong Sig; Ahn, Wha Seung

    1999-01-01

    Substantial reduction in synthesis time was achieved for zeolite L crystallization by attempting a hydrothermal synthesis at elevated temperature of 443K in a Na + /K+ mixed alkali system. Pure zeolite L could be obtained from a gel with the molar composition 5.4K 2 O-5.7Na 2 O-Al 2 O 3 -30SiO 2 -500H 2 O after 24h. Zeolite L could be obtained in high purity at the optimum Na 2 O/(K 2 O+Na 2 O) ratio of around 0.5, while zeolite W was formed when the Na 2 O/(K 2 O+Na 2 O) ratio was more than 0.66. The crystalline zeolite L samples obtained were characterized by means of elemental chemical analysis, XRD, SEM, FTi.r. spectroscopy, and particle size analyzer. In addition, two probe reaction studies were conducted. In toluene alkylation, H-L catalyst showed high catalytic activity at the beginning, but was deactivated quickly probably due to one-dimensional pore structure being blocked by the coke formed. High amounts of trimethylbenzene or diethylbenzene were observed due to the large 12-membered ring pore structure of zeolite L. Pt/NaKL catalyst prepared showed a high conversion of n-hexane and high selectivity to benzene in n-hexane aromatization reaction

  8. Thermal Properties of Zeolite-Containing Composites.

    Science.gov (United States)

    Shimonosono, Taro; Hirata, Yoshihiro; Nishikawa, Kyohei; Sameshima, Soichiro; Sodeyama, Kenichi; Masunaga, Takuro; Yoshimura, Yukio

    2018-03-13

    A zeolite (mordenite)-pore-phenol resin composite and a zeolite-pore-shirasu glass composite were fabricated by hot-pressing. Their thermal conductivities were measured by a laser flash method to determine the thermal conductivity of the monolithic zeolite with the proposed mixing rule. The analysis using composites is useful for a zeolite powder with no sinterability to clarify its thermal properties. At a low porosity thermal conductivity of the composite was in excellent agreement with the calculated value for the structure with phenol resin or shirasu glass continuous phase. At a higher porosity above 40%, the measured value approached the calculated value for the structure with pore continuous phase. The thermal conductivity of the monolithic mordenite was evaluated to be 3.63 W/mK and 1.70-2.07 W/mK at room temperature for the zeolite-pore-phenol resin composite and the zeolite-pore-shirasu glass composite, respectively. The analyzed thermal conductivities of monolithic mordenite showed a minimum value of 1.23 W/mK at 400 °C and increased to 2.51 W/mK at 800 °C.

  9. Properties of glass-bonded zeolite monoliths

    International Nuclear Information System (INIS)

    Lewis, M.A.; Fischer, D.F.; Murphy, C.D.

    1994-01-01

    It has been shown that mineral waste forms can be used to immobilize waste salt generated during the pyrochemical processing of spent fuel from the Integral Fast Reactor (IFR). Solid, leach resistant monoliths were formed by hot-pressing mixtures of salt-occluded zeolite A powders and glass frit at 990 K and 28 MPa. Additional samples have now been fabricated and tested. Normalized release rates for all elements, including iodide and chloride, were less than 1 g/m 2 d in 28-day tests in deionized water and in brine at 363 K (90 degrees C). Preliminary results indicate that these rates fall with time with both leachants and that the zeolite phase in the glass-bonded zeolite does not function as an ion exchanger. Some material properties were measured. The Poisson ratio and Young's modulus were slightly smaller in glass-bonded zeolite than in borosilicate glass. Density depended on zeolite fraction. The glass-bonded zeolite represents a promising mineral waste form for IFR salt

  10. Research and development regarding the retaining mechanism of lead ions in industrial wastewaters using natural matter with remarkable properties

    Science.gov (United States)

    Pop, A.; Iepure, G.

    2017-05-01

    The paper shows the studying of the retaining mechanism of lead ions in industrial wastewaters through static and dynamic ion exchange mechanisms. In the experimental determinations of the lead metallic ion retention, metallurgical industry wastewaters have been used on samples of volcanic zeolite tuff (from Barsana, Maramures), samples that show a high concentration of lead ions and an acidic pH. The results showed that both the static and the dynamic ion exchanges ended with good results and they were consistent with other studies conducted on clinoptilolite zeolite tuff. Knowing that the industrial sector is an important source of environment pollution and degradation and being aware of what a serious threat the heavy metal pollution is, due to their high toxicity and stability, the experiment may find applicability in different aspects, both in the Maramures mining basing as well as in the worldwide controlling and directing of the polluting processes.

  11. Powder Diffraction in Zeolite Science

    Science.gov (United States)

    Burton, Allen W.

    This tutorial discusses the fundamental principles of X-ray diffraction and its applications in zeolite science. The early sections review the physics of diffraction, crystal symmetry, and reciprocal space. We discuss how the intensity of diffracted radiation is affected both by geometric effects involving detection (the Lorentz-polarization factor) and by the arrangement of atoms within the crystal (the structure factor). The differences between powder diffraction and single-crystal diffraction are then described, and differences between X-ray and neutron diffraction are also discussed. Later sections describe the effects of symmetry, lattice substitution, crystallite size, residual strain, preferred orientation, and X-ray absorption. Special emphasis is placed on the proper application of the Scherrer analysis in reporting crystalize size. The principles of structure solution from direct methods and Patterson methods are then introduced, and a description of Rietveld analysis is given. Finally the effects of stacking disorder on a powder diffraction pattern are presented.

  12. Salt-occluded zeolite waste forms: Crystal structures and transformability

    International Nuclear Information System (INIS)

    Richardson, J.W. Jr.

    1996-01-01

    Neutron diffraction studies of salt-occluded zeolite and zeolite/glass composite samples, simulating nuclear waste forms loaded with fission products, have revealed complex structures, with cations assuming the dual roles of charge compensation and occlusion (cluster formation). These clusters roughly fill the 6--8 angstrom diameter pores of the zeolites. Samples are prepared by equilibrating zeolite-A with complex molten Li, K, Cs, Sr, Ba, Y chloride salts, with compositions representative of anticipated waste systems. Samples prepared using zeolite 4A (which contains exclusively sodium cations) as starting material are observed to transform to sodalite, a denser aluminosilicate framework structure, while those prepared using zeolite 5A (sodium and calcium ions) more readily retain the zeolite-A structure. Because the sodalite framework pores are much smaller than those of zeolite-A, clusters are smaller and more rigorously confined, with a correspondingly lower capacity for waste containment. Details of the sodalite structures resulting from transformation of zeolite-A depend upon the precise composition of the original mixture. The enhanced resistance of salt-occluded zeolites prepared from zeolite 5A to sodalite transformation is thought to be related to differences in the complex chloride clusters present in these zeolite mixtures. Data relating processing conditions to resulting zeolite composition and structure can be used in the selection of processing parameters which lead to optimal waste forms

  13. Theoretical investigation of layered zeolite frameworks: Surface properties of 2D zeolites

    Czech Academy of Sciences Publication Activity Database

    Hermann, Jan; Trachta, Michal; Nachtigall, P.; Bludský, Ota

    2014-01-01

    Roč. 227, May 15 (2014), s. 2-8 ISSN 0920-5861 R&D Projects: GA ČR GBP106/12/G015 Institutional support: RVO:61388963 Keywords : layered zeolite frameworks * surface properties * 2D zeolites Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.893, year: 2014

  14. The effect of the synthesis method on the parameters of pore structure and selectivity of ferrocyanide sorbents based on natural minerals

    International Nuclear Information System (INIS)

    Voronina, A.V.; Gorbunova, T.V.; Semenishchev, V.S.

    2017-01-01

    Ferrocyanide sorbents were obtained via thin-layer and surface modification of natural clinoptilolite and marl. The effect of modification method on surface characteristics of these sorbents and their selectivity for cesium was studied. It was shown that the modification resulted in an increase of selectivity of modified ferrocyanide sorbents to cesium as compared with the natural clinoptilolite in presence of Na + , as well as in an increase of cesium distribution coefficients in presence of K + . The nickel-potassium ferrocyanide based on the clinoptilolite showed the highest selectivity for cesium at sodium concentrations of 10 -4 -2 mol L -1 : cesium distribution coefficient was lg K d = 4.5 ± 0.4 L kg -1 and cesium/sodium separation factor was α(Cs/Na) = 250. In the presence of NH 4 + , all modified sorbents showed approximately equal selectivity for 137 Cs. Probable applications of the sorbents were suggested. (author)

  15. 1 - Aromatization of n-hexane and natural gasoline over ZSM-5 zeolite, 2- Wet catalytic oxidation of phenol on fixed bed of active carbon; 1 - Aromatisation de n-hexane et d'essence sur zeolithe ZSM-5, 2 - Oxydation catalytique en voie humide du phenol sur charbon actif

    Energy Technology Data Exchange (ETDEWEB)

    Suwanprasop, S.

    2005-04-15

    I - The production of aromatic hydrocarbons from n-hexane and natural gasoline over Pd loaded ZSM-5 zeolite in a tubular reactor was achieved under the suitable conditions at 400 deg. C, and 0.4 ml/min reactant feeding rate, employing ZSM-5 (0.5% Pd content) as a catalyst. Under these conditions, n-hexane and natural gasoline conversions were found to be 99.7% and 94.3%, respectively (with respective aromatic selectivity of 92.3% and 92.6%). II - Wet catalytic air oxidation of phenol over a commercial active carbon was studied in a three phase fixed bed reactor under mild temperature and oxygen partial pressure. Exit phenol concentration, COD, and intermediates were analysed. Oxidation of phenol was significantly improved when increasing operating temperature, oxygen partial pressure, and liquid space time, while up or down flow modes had only marginal effect. A complete model involving intrinsic kinetics and all mass transfer limitations gave convenient reactor simulation. (author)

  16. Physical, Chemical and Structural Evolution of Zeolite-Containing Waste Forms Produced from Metakaolinite and Calcined Sodium Bearing Waste (HLW and/or LLW)

    Energy Technology Data Exchange (ETDEWEB)

    Grutzeck, Michael W.

    2005-06-27

    Zeolites are extremely versatile. They can adsorb liquids and gases and serve as cation exchange media. They occur in nature as well cemented deposits. The ancient Romans used blocks of zeolitized tuff as a building material. Using zeolites for the management of radioactive waste is not a new idea, but a process by which the zeolites can be made to act as a cementing agent is. Zeolitic materials are relatively easy to synthesize from a wide range of both natural and man-made substances. The process under study is derived from a well known method in which metakaolin (an impure thermally dehydroxylated kaolinite heated to {approx}700 C containing traces of quartz and mica) is mixed with sodium hydroxide (NaOH) and reacted in slurry form (for a day or two) at mildly elevated temperatures. The zeolites form as finely divided powders containing micrometer ({micro}m) sized crystals. However, if the process is changed slightly and only just enough concentrated sodium hydroxide solution is added to the metakaolinite to make a thick crumbly paste and then the paste is compacted and cured under mild hydrothermal conditions (60-200 C), the mixture will form a hard ceramic-like material containing distinct crystalline tectosilicate minerals (zeolites and feldspathoids) imbedded in an X-ray amorphous hydrated sodium aluminosilicate matrix. Due to its lack of porosity and vitreous appearance we have chosen to call this composite a ''hydroceramic''.

  17. Physical, Chemical and Structural Evolution of Zeolite-Containing Waste Forms Produced from Metakaolinite and Calcined Sodium Bearing Waste (HLW and/or LLW)

    International Nuclear Information System (INIS)

    Grutzeck, Michael W.

    2005-01-01

    Zeolites are extremely versatile. They can adsorb liquids and gases and serve as cation exchange media. They occur in nature as well cemented deposits. The ancient Romans used blocks of zeolitized tuff as a building material. Using zeolites for the management of radioactive waste is not a new idea, but a process by which the zeolites can be made to act as a cementing agent is. Zeolitic materials are relatively easy to synthesize from a wide range of both natural and man-made substances. The process under study is derived from a well known method in which metakaolin (an impure thermally dehydroxylated kaolinite heated to ∼700 C containing traces of quartz and mica) is mixed with sodium hydroxide (NaOH) and reacted in slurry form (for a day or two) at mildly elevated temperatures. The zeolites form as finely divided powders containing micrometer ((micro)m) sized crystals. However, if the process is changed slightly and only just enough concentrated sodium hydroxide solution is added to the metakaolinite to make a thick crumbly paste and then the paste is compacted and cured under mild hydrothermal conditions (60-200 C), the mixture will form a hard ceramic-like material containing distinct crystalline tectosilicate minerals (zeolites and feldspathoids) imbedded in an X-ray amorphous hydrated sodium aluminosilicate matrix. Due to its lack of porosity and vitreous appearance we have chosen to call this composite a ''hydroceramic''

  18. Kinetic and equilibrium studies of the removal of ammonium ions from aqueous solution by rice husk ash-synthesized zeolite Y and powdered and granulated forms of mordenite

    International Nuclear Information System (INIS)

    Yusof, Alias Mohd; Keat, Lee Kian; Ibrahim, Zaharah; Majid, Zaiton Abdul; Nizam, Nik Ahmad

    2010-01-01

    The removal of ammonium from aqueous solutions using zeolite NaY prepared from a local agricultural waste, rice husk ash waste was investigated and a naturally occurring zeolite mordenite in powdered and granulated forms was used as comparison. Zeolite NaY and mordenite were well characterized by powder X-ray diffraction (XRD), energy dispersive X-ray (EDX) analysis and the total cation exchange capacity (CEC). CEC of the zeolites were measured as 3.15, 1.46 and 1.34 meq g -1 for zeolite Y, powdered mordenite and granular mordenite, respectively. Adsorption kinetics and equilibrium data for the removal of NH 4 + ions were examined by fitting the experimental data to various models. Kinetic studies showed that the adsorption followed a pseudo-second-order reaction. The equilibrium pattern fits well with the Langmuir isotherm compared to the other isotherms. The monolayer adsorption capacity for zeolite Y (42.37 mg/g) was found to be higher than that powdered mordenite (15.13 mg/g) and granular mordenite (14.56 mg/g). Thus, it can be concluded that the low cost and economical rice husk ash-synthesized zeolite NaY could be a better sorbent for ammonium removal due to its rapid adsorption rate and higher adsorption capacity compared to natural mordenite.

  19. Nanocrystalline zeolite beta and zeolite Y as catalysts in used palm oil cracking for the production of biofuel

    Science.gov (United States)

    Taufiqurrahmi, Niken; Mohamed, Abdul Rahman; Bhatia, Subhash

    2011-08-01

    Nanocrystalline zeolites with crystal size smaller than 100 nm are potential replacement for conventional zeolite catalysts due to their unique characteristics and advantages. In this study, the synthesis of nanocrystalline zeolite Y (FAU) and nanocrystalline zeolite beta (BEA) under hydrothermal conditions is reported. The effect of crystal size on the physico-chemical characteristics of the zeolite, Y (FAU), and beta (BEA) is reported. The properties of nanocrystalline zeolites Y and Beta with crystal size around 50 nm are compared with the microcrystalline zeolite Y and microcrystalline zeolite beta, respectively. The performance of the nanocrystalline zeolite as a catalyst was investigated in the cracking of used palm oil for the production of biofuel. The nanocrystalline zeolite catalytic activity was compared with the activity of microcrystalline zeolite in order to study the effect of crystal size on the catalytic activity. Both nanocrystalline zeolites gave better performance in terms of conversion of used palm oil as well as selectivity for the formation of gasoline fraction. The increase in surface area and improved accessibility of the reactant in nanocrystalline zeolites enhanced the cracking activity as well as the desired product selectivity.

  20. Sulfur tolerant zeolite supported platinum catalysts for aromatics hydrogenation

    Science.gov (United States)

    1997-04-01

    An experimental study of sulfur tolerant zeolite platinum catalysts for aormatics hydrogenation. Platinum catalysts supported on Y-zeolite have been prepared and characterized in various ways, including the hydrogenation of toluene in a high pressure...

  1. Adsorpsi Ion Logam Tembaga Menggunakan Nano Zeolit Alam yang Diaktivasi

    Directory of Open Access Journals (Sweden)

    Yulianis Yulianis

    2017-06-01

    Full Text Available This study was aimed to find out the ability of natural zeolite coming from Blang Pidie, South West Aceh District, Aceh Province, Indonesia, which was applied as an adsorbent to adsorp heavy metal copper (Cu²⁺ ions in aqueous solution. This research was conducted to enhance the performance of natural zeolite by downsizing it to nano particles, then activated physically and chemically using 0.05 M HCl, then calcined at temperature 350°C for 2 hours. Test of Cu²⁺ metal ion adsorption to nano natural zeolite after activation was done by batch method to determine the effect of contact time, weight of the adsorbent, pH, and initial concentration. The results showed that the optimum adsorption at the initial concentration 38.998 mg/L, weight adsorbent 1 gram, pH 6 during 120 minutes of the contact time with the percentage metal ion Cu²⁺ adsorption up to 99.86% and adsorption capacity 7.789 mg/g. Isothermal adsorption ressembled with the isotherms Freundlich with the R² value of 0.9685, Freundlich constants (Kf 111.99 mg/g and n value 0.986. The kinetic studies indicated that the adsorption of metal ions Cu²⁺ could be described by pseudo second order kinetic model with linear regression value 0.9997 and a constant value 0.121 min-1.ABSTRAK Penelitian ini bertujuan untuk melihat kemampuan zeolit alam yang berasal dari Blang Pidie, Kabupaten Aceh Barat Daya, Provinsi Aceh, Indonesia yang diaplikasikan sebagai adsorben untuk menyerap ion logam berat tembaga (Cu²⁺ dalam larutan. Penelitian dilakukan dengan peningkatan unjuk kerja zeolit alam melalui pengecilan ukuran sampai nano partikel, selanjutnya diaktivasi fisika dan aktivasi kimia menggunakan HCl 0,05 M kemudian dikalsinasi pada temperatur 350 oC selama 2 jam. Uji adsorpsi ion logam Cu²⁺ terhadap nano zeolit alam setelah aktivasi dilakukan dengan metode batch untuk menentukan pengaruh waktu kontak, berat adsorben, pH, dan konsentrasi awal. Hasil penelitian menunjukkan adsorpsi

  2. Effect of the Feed Additive Clinoptilolite (ZeoFeed on Nutrient Metabolism and Production Performance of Laying Hens

    Directory of Open Access Journals (Sweden)

    Miroslav Macháček

    2010-01-01

    Full Text Available The aim of this study was to assess the effects of two levels of clinoptilolite administered in feed (2% and 4% on some selected performance indicators, metabolic utilization of basic nutrients and the health status of laying hens. The selected 24 Bovans Goldline hybrid laying hens were divided into three equal groups, two experimental groups (E1 and E2 and one control group (C. The laying hens were housed individually in cages with an automatic supply of drinking water, manual feeding, in a setting with controlled light and temperature regimens. Hens from individual groups were all fed a complete feed mix of the same composition and the only difference was in clinoptilolite supplementation: feed mixes for E1 and E2 groups contained 2% and 4% of clinoptilolite (commercial additive ZeoFeed respectively, replacing the same amounts of wheat. The hens received feed mixes and drinking water ad libitum. During this 28-day experiment, feed consumption and the number and weight of eggs laid were monitored individually for each hen. At the end of the experiment, the balance test using the indicator method (Cr2O3 was performed in all eight hens in each of the groups. The results of balance tests were then used to calculate the metabolic utilization of selected nutrients (nitrogen, fat, ash, nitrogen-free extracts, starch, gross energy, Ca, P. After the balance tests, blood samples for haematological and biochemical examinations were collected via puncture of the vena basilica. The addition of 2% clinoptilolite to feed mix resulted in a highly significant (P ⪬ 0.01 increase in mean egg weight to 64.69 g, but the addition of 4% clinoptilolite in group E2 resulted in a highly significant (P ⪬ 0.01 decrease in mean egg weight to 62.20 g compared to the control (63.73 g. Moreover, daily feed mix consumption in group E1 decreased to 114 g per one laying hen/day compared to the controls (118 g per one laying hen/day. In group E2 (4% clinoptilolite, daily

  3. Zeolite Membranes: Ozone Detemplation, Modeling, and Performance Characterization

    OpenAIRE

    Kuhn, J.

    2009-01-01

    Membrane technology plays an increasingly important role in developing a more sustainable process industry. Zeolites are a novel class of membrane materials with unique properties enabling molecular sieving and affinity based separations. This thesis proposes some new concepts in zeolite membrane synthesis, application, and modeling. The influence of zeolite polarity is assessed and the use of a hydrophobic zeolite membrane for water separation is explored. Ozonication, a novel method for zeo...

  4. Polyphosphates substitution for zeolite to in detergents

    International Nuclear Information System (INIS)

    Restrepo V, Gloria M.; Ocampo G, Aquiles; Saldarriaga M, Carlos

    1996-01-01

    The detergents, as well as the cleaning products, contain active ingredients that are good to increase their efficiency and some of them, as the sodium Tripoli-phosphate (TPF), they have turned out to be noxious for the environment. The zeolites use in the formulation of detergents has grown substantially since they fulfill the same function of the TPF and they have been recommended ecologically as substitutes from these when not being polluting. The objective of this work is to obtain a zeolite with appropriate characteristics for its use in the formulation of detergents, reproducing those of the zeolites used industrially. The zeolite synthesis is studied 4A starting from hydro-gels of different composition, varying the operation conditions and using two raw materials: (sodium meta-silicate, commercial degree and metallic aluminum) and clay type kaolin like silica source and aluminum It is looked for to get a product of beveled cubic morphology, or spherical, with glass size between 1 and 3 microns and that it possesses good capacity of conical exchange. Since the capacity and speed of ionic exchange is influenced by the particle size, time of contact and temperature, experimentation conditions settle down to measure the exchange of ions calcium and magnesium in watery solutions that they simulate the real situation of a laundry process in the country. This way the ability of the zeolite 4A obtained to diminish the concentration of these ions in the laundry waters is evaluated and its possibilities like component in the formulation of detergents non-phosphatates. Of the synthesized zeolites, the best in agreement is chosen with chemical properties as ionic and physical exchange capacity as crystalline, particle size and color, to prepare a detergent in which the polyphosphates is substituted partial and totally for the synthesized zeolite

  5. Molecular Simulation of Adsorption in Zeolites

    Science.gov (United States)

    Bai, Peng

    Zeolites are a class of crystalline nanoporous materials that are widely used as catalysts, sorbents, and ion-exchangers. Zeolites have revolutionized the petroleum industry and have fueled the 20th-century automobile culture, by enabling numerous highly-efficient transformations and separations in oil refineries. They are also posed to play an important role in many processes of biomass conversion. One of the fundamental principles in the field of zeolites involves the understanding and tuning of the selectivity for different guest molecules that results from the wide variety of pore architectures. The primary goal of my dissertation research is to gain such understanding via computer simulations and eventually to reach the level of predictive modeling. The dissertation starts with a brief introduction of the applications of zeolites and computer modeling techniques useful for the study of zeolitic systems. Chapter 2 then describes an effort to improve simulation efficiency, which is essential for many challenging adsorption systems. Chapter 3 studies a model system to demonstrate the applicability and capability of the method used for the majority of this work, configurational-bias Monte Carlo simulations in the Gibbs ensemble (CBMC-GE). After these methodological developments, Chapter 4 and 5 report a systematic parametrization of a new transferable force field for all-silica zeolites, TraPPE-zeo, and a subsequent, relatively ad-hoc extension to cation-exchanged aluminosilicates. The CBMC-GE method and the TraPPE-zeo force field are then combined to investigate some complex adsorption systems, such as linear and branched C6-C 9 alkanes in a hierarchical microporous/mesoporous material (Chapter 6), the multi-component adsorption of aqueous alcohol solutions (Chapter 7) and glucose solutions (Chapter 8). Finally, Chapter 9 describes an endeavor to screen a large number of zeolites with the purpose of finding better materials for two energy-related applications

  6. The Effect of zeolite addition on viability of paddy straw mushroom spawn

    Directory of Open Access Journals (Sweden)

    DJUMHAWAN RATMAN PERMANA

    2007-01-01

    Full Text Available The objective of this research was to increase the viability of the paddy straw mushroom spawn by adding natural stone on the media’s composition for the paddy straw mushroom spawn. Mycelium of the paddy straw mushroom was take from the pure development of the paddy straw mushroom which was planted on the various treatment for media e.i. 100% cotton media and rice bran + 0% zeolite (A, 75% cotton media and rice bran + 25% zeolite (B, 50% cotton media and rice bran + 50% zeolite (C, 25% cotton and rice bran + 75% zeolite (D, 0% cotton media and rice bran + 100% rice bran (E. Each treatment was observed for the length of mycelium, the concentration of reduced sugar, total carbon and water content, spawn media weight, pH and temperature. Results demonstrated that there is a positive effect of zeolite added to the paddy straw mushroom media. The zeolite able to adsorbed nutrient through its pores, so the mycelium of the paddy straw mushroom able to use the nutrient gradually and equally appropriate with its growth. Therefore the viability of the paddy straw mushroom is increase. Result showed that the B is the best viability in the Potetos Dectrose Agar (PDA media, that has viability power up to 50 days after inoculation and the temperature are 29,6 0C, then followed by treatment C, D, A and E, each has viability power up to 42; 38; 34; 22 days after inoculation and the maximum length of each mycelium are 17.5; 9.2; 0.9; 0.5 cm, but in the treatment D being contaminated by Aspergillus sp.

  7. Zeolites and Zeotypes for Oil and Gas Conversion

    NARCIS (Netherlands)

    Vogt, Eelco T C; Whiting, Gareth T.; Dutta Chowdhury, Abhishek; Weckhuysen, Bert M.

    2015-01-01

    Zeolite-based catalyst materials are widely used in chemical industry. In this chapter, the applications of zeolites and zeotypes in the catalytic conversion of oil and gas are reviewed. After a general introduction to zeolite science and technology, we discuss refinery applications, such as fluid

  8. defluorination of drinking water using surfactant modified zeolites

    African Journals Online (AJOL)

    PUBLICATIONS1

    The unmodified zeolite NaLSX was incapable of adsorbing fluoride ions but the surfactant modified zeolite adsorbed fluoride. The fluoride adsorption capacity of the modified zeolite was. pH dependent and peaked at pH 6.0 – 7.0. INTRODUCTION. Groundwater is often presumed to be fairly safe for consumption compared ...

  9. Influencing the selectivity of zeolite Y for triglycine adsorption

    NARCIS (Netherlands)

    Wijntje, R.; Bosch, H.; Haan, A.B. de; Bussmann, P.J.T.

    2007-01-01

    In prior work we studied the adsorption of triglycine on zeolite Y under reference conditions. This study aims to solve the question of which adsorbent properties and process conditions influence the adsorption triglycine from an aqueous solution by zeolite Y. Relevant zeolite parameters to study

  10. Molecular simulations and experimental studies of zeolites

    Science.gov (United States)

    Moloy, Eric C.

    Zeolites are microporous aluminosilicate tetrahedral framework materials that have symmetric cages and channels with open-diameters between 0.2 and 2.0 nm. Zeolites are used extensively in the petrochemical industries for both their microporosity and their catalytic properties. The role of water is paramount to the formation, structure, and stability of these materials. Zeolites frequently have extra-framework cations, and as a result, are important ion-exchange materials. Zeolites also play important roles as molecular sieves and catalysts. For all that is known about zeolites, much remains a mystery. How, for example, can the well established metastability of these structures be explained? What is the role of water with respect to the formation, stabilization, and dynamical properties? This dissertation addresses these questions mainly from a modeling perspective, but also with some experimental work as well. The first discussion addresses a special class of zeolites: pure-silica zeolites. Experimental enthalpy of formation data are combined with molecular modeling to address zeolitic metastability. Molecular modeling is used to calculate internal surface areas, and a linear relationship between formation enthalpy and internal surface areas is clearly established, producing an internal surface energy of approximately 93 mJ/m2. Nitrate bearing sodalite and cancrinite have formed under the caustic chemical conditions of some nuclear waste processing centers in the United States. These phases have fouled expensive process equipment, and are the primary constituents of the resilient heels in the bottom of storage tanks. Molecular modeling, including molecular mechanics, molecular dynamics, and density functional theory, is used to simulate these materials with respect to structure and dynamical properties. Some new, very interesting results are extracted from the simulation of anhydrous Na6[Si6Al 6O24] sodalite---most importantly, the identification of two distinct

  11. Characterization of Zeolite in Zeolite-Geopolymer Hybrid Bulk Materials Derived from Kaolinitic Clays.

    Science.gov (United States)

    Takeda, Hayami; Hashimoto, Shinobu; Yokoyama, Hiroaki; Honda, Sawao; Iwamoto, Yuji

    2013-05-06

    Zeolite-geopolymer hybrid materials have been formed when kaolin was used as a starting material. Their characteristics are of interest because they can have a wide pore size distribution with micro- and meso-pores due to the zeolite and geopolymer, respectively. In this study, Zeolite-geopolymer hybrid bulk materials were fabricated using four kinds of kaolinitic clays (a halloysite and three kinds of kaolinite). The kaolinitic clays were first calcined at 700 °C for 3 h to transform into the amorphous aluminosilicate phases. Alkali-activation treatment of the metakaolin yielded bulk materials with different amounts and types of zeolite and different compressive strength. This study investigated the effects of the initial kaolinitic clays on the amount and types of zeolite in the resultant geopolymers as well as the strength of the bulk materials. The kaolinitic clays and their metakaolin were characterized by XRD analysis, chemical composition, crystallite size, 29 Si and 27 Al MAS NMR analysis, and specific surface area measurements. The correlation between the amount of zeolite formed and the compressive strength of the resultant hybrid bulk materials, previously reported by other researchers was not positively observed. In the studied systems, the effects of Si/Al and crystalline size were observed. When the atomic ratio of Si/Al in the starting kaolinitic clays increased, the compressive strength of the hybrid bulk materials increased. The crystallite size of the zeolite in the hybrid bulk materials increased with decreasing compressive strength of the hybrid bulk materials.

  12. Deuterium exchange with the surface hydrogen of zeolite catalysts. 7. Nickel-containing zeolites

    International Nuclear Information System (INIS)

    Minachev, Kh.M.; Dmitriev, R.V.; Penchev, V.; Kanazirev, V.; Minchev, Kh.; Kasimov, Ch.K.

    1982-01-01

    An in-depth study of heteromolecular isotopic hydrogen exchange (HIHE) in Ni zeolites was undertaken with a view to measuring surface OH group concentrations and determining effectiveness of Ni, on the one hand, and Pd and Pt, on the other, in promoting chemical reactions. Here the degree of metal dispersion in the Ni zeolite was characterized through H 2 chemisorption and thermosorption data. A study was made of the action of these zeolites in catalyzing the disproportionation of toluene. The data obtained here have given an understanding of the effect of the metal, the OH-group concentration, and the mutual arrangement of OH groups and Ni atoms on catalyzed toluene reactions. Results indicated that HIHE occurs on reduced nickel-containing zeolite catalysts at temperatures in excess of 100 0 C, and is limited by the rate of transport of activated hydrogen from the metal particles on the support surface. High-temperature oxidation-reduction of the nickel-containing zeolite-leads to the formation of coarse nickel crystals on the external zeolite crystal faces. Also, the reduced NiCaNaY zeolites show high catalytic activity in the toluene disproportionation only when the nickel has been introduced through ion exchange. Both isotopic exchange and toluene disproportionation are promoted when the nickel particles and OH groups are in close proximity

  13. Synthesis and Characterization of Zeolite Na−Y and Its Conversion to the Solid Acid Zeolite H−Y

    DEFF Research Database (Denmark)

    Warner, Terence Edwin; Galsgaard Klokker, Mads; Nielsen, Ulla Gro

    2017-01-01

    various preparative strategies with the students, such as the three-stage procedure described here. Stage I concerns the hydrothermal synthesis of zeolite Na−Y, followed by ion-exchange with an ammonium acetate solution to form zeolite NH4−Y, and the latter is subsequently converted to zeolite H...

  14. Adsorption and photophysics of fullerene C60 at liquid-zeolite particle interfaces: unusually high affinity for hydrophobic, ultrastabilized zeolite Y.

    Science.gov (United States)

    Ellison, Eric H

    2006-06-15

    Adsorption of fullerene C60 from solution to the external surface of zeolite particles has been investigated. The most intriguing result of this study was the nature of C60 adsorption to ultrastablized zeolite Y (or USY). Two commercial samples of USY were tested: CBV780 (Y780) and CBV901 (Y901). Y901 was shown in previous reports to be more hydrophobic than Y780. Higher affinity of C60 for Y901 was found relative to Y780 in a variety of hydrocarbon solvents, including toluene and cyclohexane. In these same solvents, weak or no affinity for Y901 of typical arenes such as naphthalene or pyrene was observed. In toluene, adsorption isotherms for C60 gave dissociation constants (and values of saturation binding) = 0.5 microM (5.8 micromol g(-1)) and 8 microM (1.4 micromol g(-1)) for Y901 and Y780, respectively. C60 was estimated to cover nearly one-half of the estimated external surface area of Y901 particles at saturation. Significant adsorption of C60 to the ionic zeolites NaX, NaY, and KL was observed in cyclohexane but not in toluene, consistent with the pi-cation effect as a driving force for adsorption to these materials. The main driving force for C60 adsorption to Y901 is postulated to involve the interaction of C60 with lone pair electrons of framework oxygen atoms of the 12-ring entry aperture to the supercage. In the 12-ring site, C60 is located in half-supercage bowls on the exterior particle surface. The adsorptive interaction on Y901 relies on the spherical shape of C60 and the hydrophobicity of the zeolite surface. On ionic zeolites, the presence of specific adsorption sites such as exchangeable cations and hydroxyl groups hinder the special positioning necessary for C60 interaction with the 12-ring site. The ground-state and triplet-state absorption spectrum of adsorbed C60 was solution-like on all zeolites. Quenching of the C60 triplet state was examined by using transient absorption spectroscopy. Rate constants for quenching by rubrene, ferrocene, and

  15. An oxalate selective electrode based on modified PVC-membrane with tetra-butylammonium--Clinoptilolite nanoparticles.

    Science.gov (United States)

    Hoseini, Zohre; Nezamzadeh-Ejhieh, Alireza

    2016-03-01

    A modified PVC-membrane electrode with tetra-butylammonium bromide - Clinoptilolite nano-particles (TBA-NCP) showed good Nernstian slope (29.9±0.6 mV per decade of oxalate concentration) in concentration range of 3.1×10(-7)-8.3×10(-1) mol L(-1) with a detection limit of 1.5×10(-7) mol L(-1). The best performance was obtained with a membrane composition of 31.5% PVC, 62.5% DOP and 6% TBA-NCP in the temperature range of 20-35 °C and the pH range of 4-9. The fast response time and good reproducibility over a period of 3 months are other characteristics of the sensor. The proposed electrode was successfully used as an indicator electrode in titration of oxalate ions with CaCl2 solution. The proposed electrode was also used in direct potentiometric determination of oxalate in many real samples such as: mushroom, black and green tea, spinach and beet. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. The use in grass production of clinoptilolite as an ammonia adsorbent and a nitrogen carrier

    Directory of Open Access Journals (Sweden)

    Milovanović Jelena

    2015-01-01

    Full Text Available The clinoptilolite-rich tuff (NZ from Zlatokop deposit (Vranjska Banja, Serbia has been studied as a nitrogen carrier for grass production. Mechanism of binding ammonium cations present in water solutions by NZ has been examined as well as possibility of adsorption of ammonia released in fresh cattle manure during its fermentation. The NH4+ binding from solutions proceeds via an ion-exchange process which follows the pseudo-second-order kinetics. Adsorption isotherms studied at 298-318 K follow the Freundlich isotherm equation. The NZ readily adsorbs ammonia liberated from manure and an addition of 10 wt.% of NZ to manure can preserve up to 90% of ammonia. The potential benefit of this effect has been examined in greenhouse pot experiments with the Italian ryegrass (Lolium multiflorum, var. Macho using three different types of soil (silty, clayey and sandy. The zeta potential measurements show that stability of their colloidal dispersions differs mutually and that addition of the NZ differently affects the stability and nitrogen cycling. All results indicate that NZ can be applied in grass production. [Projekat Ministarstva nauke Republike Srbije, br. 172018 and Norwegian Programme in Higher Education, Research and Development HERD

  17. Immobilisation of 137Cs and 90Sr in hot-pressed clinoptilolite

    International Nuclear Information System (INIS)

    Briggs, A.; Jones, D.V.C.; Cole, G.B.; Valentine, T.M.; Preston, R.F.; Hawes, R.W.M.; Fones, M.D.

    1984-07-01

    It is shown that clinoptilolites from Nevada and Mudhills, California, can be vitrified by hot-pressing at 1000 to 1050 deg C for 30 min under 23 MPa pressure in graphite dies, or for 10 min under 3.5 MPa pressure in stainless steel bellows-shaped containers. Activity measurements before and after hot-pressing show that the radionuclides 137 Cs and 90 Sr are retained almost completely during the process. The hot-pressed material is shown to be extremely resistant to leaching of the nuclides, either in Soxhlet or long-term static leach tests. Gamma-irradiation increases their leachability; that of 90 Sr more than that of 137 Cs, but even so, the leach rates of both remain very low. X-ray diffraction spectra taken before and after heat-treatment for 10 days at temperatures up to 1000 deg C show no deleterious effects, and hydrothermal treatments at temperatures up to 90 deg C for 100 days, even in the presence of sodium ions in solution, are shown not to cause any changes detectable by X-ray diffraction. (author)

  18. Limestone and Zeolite as Alternative Media in Horizontal Subsurface Flow Constructed Wetlands: Laboratory-Scale Studies

    Science.gov (United States)

    Lizama, K.; Jaque, I.; Ayala, J.

    2016-12-01

    Arsenic is well known for its chronic toxicity. Millions of people around the world are currently at risk, drinking water with As concentrations above 10 ppb, the WHO drinking water guideline. Although different treatment options exist, they are often limited by elevated costs and maintenance requirements. Constructed wetlands are a natural water treatment system, capable to remove metals and metalloids -including As- via different physical, chemical and biological processes. The use of alternative supporting media to enhance As removal in subsurface flow wetlands has been recommended, but not sufficiently studied. Limestone and zeolite have been identified as effective supporting media in subsurface flow wetlands aiming As removal. However, there are still key aspects to be addressed, such as the implications of using these media, the speciation in the solid phase, the role of vegetation, etc. This study investigated the performance of limestone and zeolite in three types of experiments: batch, column and as main supporting media in a bench scale horizontal subsurface flow wetland system. Synthetic water resembling a contaminated river in Chile (As concentration=3 mg/L, Fe concentration= 100 mg/L, pH=2) was used in all experiments. In the batch experiments, the As concentration, the mass of media and the contact time were varied. The column system consisted of three limestone columns and three zeolite columns, operated under a hydraulic loading of 20 mm/d. The wetland system consisted of twelve PVC cells: six filled with zeolite and six with limestone. Phragmites australis were planted in three cells of each media type, as control cells. From the batch experiments, maximum As sorption capacities as indicated by Langmuir model were 1.3 mg/g for limestone and 0.17 mg/g for zeolite, at 18 h contact time and 6.3 g/L medium concentration. EDS and XPS analyses revealed that As and Fe were retained in zeolite at the end of the batch experiments. Zeolite and limestone

  19. Reorientational dynamics of water confined in zeolites.

    Science.gov (United States)

    Fogarty, Aoife C; Coudert, François-Xavier; Boutin, Anne; Laage, Damien

    2014-02-24

    We present a detailed molecular-dynamics study of water reorientation and hydrogen-bond dynamics in a strong confinement situation, within the narrow pores of an all-silica Linde type A (LTA) zeolite. Two water loadings of the zeolite are compared with the bulk case. Water dynamics are retarded in this extreme hydrophobic confinement and the slowdown is more pronounced at higher water loading. We show that water reorientation proceeds mainly by large-amplitude angular jumps, whose mechanism is similar to that determined in the bulk. The slowdown upon hydrophobic confinement arises predominantly from an excluded-volume effect on the large fraction of water molecules lying at the interface with the zeolite matrix, with an additional minor contribution coming from a structuring effect induced by the confinement. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Characterization and antibacterial activity of silver exchanged regenerated NaY zeolite from surfactant-modified NaY zeolite

    Energy Technology Data Exchange (ETDEWEB)

    Salim, Mashitah Mad; Malek, Nik Ahmad Nizam Nik, E-mail: niknizam@fbb.utm.my

    2016-02-01

    The antibacterial activity of regenerated NaY zeolite (thermal treatment from cetyltrimethyl ammonium bromide (CTAB)-modified NaY zeolite and pretreatment with Na ions) loaded with silver ions were examined using the broth dilution minimum inhibitory concentration (MIC) method against Escherichia coli (E. coli ATCC 11229) and Staphylococcus aureus (S. aureus ATCC 6538). X-ray diffraction (XRD), attenuated total reflectance–Fourier transform infrared (ATR–FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) and chemical elemental analyses were used to characterize the regenerated NaY and AgY zeolites. The XRD patterns indicated that the calcination and addition of silver ions on regenerated NaY zeolite did not affect the structure of the regenerated NaY zeolite as the characteristic peaks of the NaY zeolite were retained, and no new peaks were observed. The regenerated AgY zeolite showed good antibacterial activity against both bacteria strains in distilled water, and the antibacterial activity of the samples increased with increasing Ag loaded on the regenerated AgY zeolite; the regenerated AgY zeolite was more effective against E. coli than S. aureus. However, the antibacterial activity of the regenerated AgY was not effective in saline solution for both bacteria. The study showed that CTAB-modified NaY zeolite materials could be regenerated to NaY zeolite using thermal treatment (550 °C, 5 h) and this material has excellent performance as an antibacterial agent after silver ions loading. - Highlights: • Thermal treatment was used to regenerate surfactant modified zeolite. • The regenerated NaY zeolite formed was added with different silver loadings. • Regenerated AgY zeolite was tested for antibacterial activity on E. coli and S. aureus. • The antibacterial activity increased with increased of the amount of silver loadings. • The zeolite structure did not change with thermal and modification

  1. Adsorption of Water and Ethanol in MFI-Type Zeolites

    KAUST Repository

    Zhang, Ke

    2012-06-12

    Water and ethanol vapor adsorption phenomena are investigated systematically on a series of MFI-type zeolites: silicalite-1 samples synthesized via both alkaline (OH -) and fluoride (F -) routes, and ZSM-5 samples with different Si/Al ratios as well as different charge-balancing cations. Full isotherms (0.05-0.95 activity) over the range 25-55 °C are presented, and the lowest total water uptake ever reported in the literature is shown for silicalite-1 made via a fluoride-mediated route wherein internal silanol defects are significantly reduced. At a water activity level of 0.95 (35 °C), the total water uptake by silicalite-1 (F -) was found to be 0.263 mmol/g, which was only 12.6%, 9.8%, and 3.3% of the capacity for silicalite-1 (OH -), H-ZSM-5 (Si/Al:140), and H-ZSM-5 (Si/Al:15), respectively, under the same conditions. While water adsorption shows distinct isotherms for different MFI-type zeolites due to the difference in the concentration, distribution, and types of hydrophilic sites, the ethanol adsorption isotherms present relatively comparable results because of the overall organophilic nature of the zeolite framework. Due to the dramatic differences in the sorption behavior with the different sorbate-sorbent pairs, different models are applied to correlate and analyze the sorption isotherms. An adsorption potential theory was used to fit the water adsorption isotherms on all MFI-type zeolite adsorbents studied. The Langmuir model and Sircar\\'s model are applied to describe ethanol adsorption on silicalite-1 and ZSM-5 samples, respectively. An ideal ethanol/water adsorption selectivity (α) was estimated for the fluoride-mediated silicalite-1. At 35 °C, α was estimated to be 36 for a 5 mol % ethanol solution in water increasing to 53 at an ethanol concentration of 1 mol %. The adsorption data demonstrate that silicalite-1 made via the fluoride-mediated route is a promising candidate for ethanol extraction from dilute ethanol-water solutions. © 2012

  2. Adsorption Cooling System Using Metal-Impregnated Zeolite-4A

    Directory of Open Access Journals (Sweden)

    Somsuk Trisupakitti

    2016-01-01

    Full Text Available The adsorption cooling systems have been developed to replace vapor compression due to their benefits of being environmentally friendly and energy saving. We prepared zeolite-4A and experimental cooling performance test of zeolite-water adsorption system. The adsorption cooling test-rig includes adsorber, evaporator, and condenser which perform in vacuum atmosphere. The maximum and minimum water adsorption capacity of different zeolites and COP were used to assess the performance of the adsorption cooling system. We found that loading zeolite-4A with higher levels of silver and copper increased COP. The Cu6%/zeolite-4A had the highest COP at 0.56 while COP of zeolite-4A alone was 0.38. Calculating the acceleration rate of zeolite-4A when adding 6% of copper would accelerate the COP at 46%.

  3. Development of spent salt treatment technology by zeolite column system. Performance evaluation of zeolite column

    International Nuclear Information System (INIS)

    Miura, Hidenori; Uozumi, Koichi

    2009-01-01

    At electrorefining process, fission products(FPs) accumulate in molten salt. To avoid influence on heating control by decay heat and enlargement of FP amount in the recovered fuel, FP elements must be removed from the spent salt of the electrorefining process. For the removal of the FPs from the spent salt, we are investigating the availability of zeolite column system. For obtaining the basic data of the column system, such as flow property and ion-exchange performance while high temperature molten salt is passing through the column, and experimental apparatus equipped with fraction collector was developed. By using this apparatus, following results were obtained. 1) We cleared up the flow parameter of column system with zeolite powder, such as flow rate control by argon pressure. 2) Zeolite 4A in the column can absorb cesium that is one of the FP elements in molten salt. From these results, we got perspective on availability of the zeolite column system. (author)

  4. CONVERSION OF (±-CITRONELLAL AND ITS DERIVATIVES TO (--MENTHOL USING BIFUNCTIONAL NICKEL ZEOLITE CATALYSTS

    Directory of Open Access Journals (Sweden)

    Indri Badria Adilina

    2015-06-01

    Full Text Available (±-Citronellal and its derivatives were conv