WorldWideScience

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. 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.

  3. Surface effect of natural zeolite (clinoptilolite) on the photocatalytic activity of TiO2

    International Nuclear Information System (INIS)

    Li Fangfei; Jiang Yinshan; Yu Lixin; Yang Zhengwen; Hou Tianyi; Sun Shenmei

    2005-01-01

    The surface interaction between TiO 2 and natural zeolite, clinoptilolite, has been investigated by means of transmission electron microscope (TEM), atom force microscope (AFM), X-ray diffractometer (XRD), diffuse reflectance infrared Fourier transform (DRIFT) and far Fourier transform infrared ray (FTIR) spectroscopy. And the photocatalytic degradation (PCD) rate of methyl orange (MO), a model of recalcitrant azo dye, in aqueous system has been measured to compare the photocatalytic activities of different photocatalysts. A model has been carried out to explain the incorporation between TiO 2 particles and natural zeolite. The results show that the TiO 2 particles loaded on zeolite are 50 nm or so, smaller than the pure one, and combine with zeolite via chemical force. Since the reserved adsorption ability and the existence of electron trapper, the TiO 2 -zeolite performed more efficient at low initial concentration and in the later period of PCD process, as compared with pure TiO 2 nanopowders

  4. 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...

  5. Sorption of cobalt in zeolites and natural clays of the clinoptilolite and kaolinite type

    International Nuclear Information System (INIS)

    Davila R, J.I.; Solache R, M.

    2006-01-01

    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)

  6. INVESTIGATION OF CLINOPTILOLITE NATURAL ZEOLITE REGENERATION BY AIR STRIPPING FOLLOWED BY ION EXCHANGE FOR REMOVAL OF AMMONIUM FROM AQUEOUS SOLUTIONS

    Directory of Open Access Journals (Sweden)

    A. R. Rahmani ، M. T. Samadi ، H. R. Ehsani

    2009-07-01

    Full Text Available The purpose of this study was to regenerate clinoptilolite natural zeolite by air stripping followed by removal of ammonium from aqueous solutions. The research was carried out in continuous system. The characteristics of graded clinoptilolite from Semnan (one of the central provinces in Iran mines were determined and then regeneration tests were done by contacting of 1 N NaCl solution with given weights of ammonium saturated zeolite. Then the brine of column was transferred to the air stripping column for regeneration. The pH of brine solution before entrance to a stripping column was increased to 11. Air stripped ammonia from the brine was converted to the ammonium ion by using acid scrubber. The outlet effluent from stripping column was collected for reuse. The results showed that the cation exchange capacities were 17.31 to 18.38 mg NH4+/g of zeolite weight. Regeneration efficiency of zeolite by NaCl solution and air stripping was in the range of 92%-97% under various operational conditions. However, the efficiency of acid absorption of released ammonia in stripping process was 55% with a major rejection of the surplus ammonia to the atmosphere. It could be concluded that the method studied may be considered as an advanced and supplementary process for treating effluents of aqueous solution and fishponds in existing treatment plants.

  7. Investigation of using Zeolite A and P synthesized from Iranian natural clinoptilolite for removal of heavy cations from simulated wastes

    International Nuclear Information System (INIS)

    Ghasemi Mbtaker, H.; Kazemiyan, H.; Maleki Nejad, A.; Zeinali, M. A. A.; Pakzad, M. R.

    2006-01-01

    Various methods have been used for the the removal o f heavy metal cations from mineral and industrial wastes. This research deals with the use of synthetic zeolites A and P synthesized from natural clinoptilolite for the removal process because of their superiority to ones. Ion exchange capacity of natural and synthetic samples was determined, then, the effects of some parameters such as temperature, time, and acidity on sorption were investigated as well as continues sorption. The sorption of lead cations was much better than that of other cations with the use of the synthetic samples and the rise in temperature and in pH has no significant effect. Sorption of this cations on the column was good. The results of cadmium sorption was promising and increasing the temperature increased the sorption and decreasing the pH decreased it. The sorption of zinc was rationally good; however it was less than previous cations, and increased with increasing the temperature. The results of nickel sorption in comparison with other cation, at high concentration was not promising. However, the results, at low concentration were good. Temperature had strong effect on nickel sorption

  8. 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)

  9. 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.

  10. 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

  11. 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)

  12. A density functional theory study of arsenic immobilization by the Al(III)-modified zeolite clinoptilolite

    NARCIS (Netherlands)

    Awuah, Joel B.; Dzade, N.Y.; Tia, Richard; Adei, Evans; Kwakye-Awuah, Bright; Catlow, C. Richard A.; de Leeuw, Nora H.

    2016-01-01

    We present density functional theory calculations of the adsorption of arsenic acid (AsO(OH)3) and arsenous acid (As(OH)3) on the Al(III)-modified natural zeolite clinoptilolite under anhydrous and hydrated conditions. From our calculated adsorption energies, we show that adsorption of both arsenic

  13. Drying and purification of natural gas by clinoptilolite on an experimental pilot plant

    Energy Technology Data Exchange (ETDEWEB)

    Tsitsishvili, G V; Urotadze, S L; Lukin, V D; Bagirov, R M

    1976-02-01

    The paper deals with the process of the drying and purification of natural gas from CO/sub 2/ on an experimental pilot plant using the natural zeolite clinoptilolite. On the basis of the obtained data the dynamic activity of clinoptilolite against water and CO/sub 2/ has been calculated.

  14. 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 .

  15. 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

  16. 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)

  17. 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...

  18. Structural simulation of natural zeolites

    International Nuclear Information System (INIS)

    Sanchez P, E.; Carrera G, L.M.

    1997-01-01

    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)

  19. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Clinoptilolite zeolite influence on inorganic nitrogen in silt loam and sandy agricultural soils

    Science.gov (United States)

    Development of best management practices can help improve inorganic nitrogen (N) availability to plants and reduce nitrate-nitrogen (NO3-N) leaching in soils. This study was conducted to determine the influence of the zeolite mineral Clinoptilolite (CL) additions on NO3-N and ammonium-nitrogen (NH4...

  2. Clinoptilolite zeolite influence on nitrogen in a manure-amended sandy agricultural soil

    Science.gov (United States)

    Development of best management practices can help improve inorganic nitrogen (N) availability to plants and reduce nitrate-nitrogen (NO3-N) leaching in soils. This study was conducted to determine the influence of the zeolite mineral clinoptilolite (CL) additions on NO3-N and ammonium-nitrogen (NH4-...

  3. 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)

  4. Ion exchange and dehydration experimental studies of clinoptilolite: Implications to zeolite dating

    International Nuclear Information System (INIS)

    WoldeGabriel, G.

    1995-02-01

    Variable effects were noted on the argon (Ar) and potassium (K) contents of clinoptilolite fractions used in ion-exchange and dehydration experiments. The K contents of clinoptilolite fractions were differently affected during cation exchange with Ca-, Cs-, K-, and Na-chloride solutions. Ar was generally less affected during these experiments, except for a Na-clinoptitolite fraction exchanged for five days. Loss of Ar during organic heavy-liquid treatment and cleaning using acetone and deionized water does occur, as indicated by comparing the amounts of radiogenic Ar of treated and untreated fractions. Moreover, a regular decrease in radiogenic Ar contents was noted in clinoptilolite fractions during dehydration experiments at different temperatures for 16 hours. Comparable losses do not occur from saturated samples that were heated in 100 C for more than five months. Water appears to play a vital role in stabilizing the clinoptilolite framework structure and in the retention of Ar. The radiogenic Ar depletion pattern noted in clinoptilolite fractions dehydrated in unsaturated environment at different temperatures is similar to variations in the amount of radiogenic Ar observed in clinoptilolite samples from the unsaturated zone of an altered tuff. These results can be used to evaluate the extent of zeolitic water (and hence Ar) retention in unsaturated geologic settings. The utility of alkali zeolites (e.g., phillipsite, clinoptilolite, and mordenite) from low-temperature, open-hydrologic alteration as potential dateable minerals was evaluated using the K/Ar method as part of the Yucca Mountain Site Characterization Project, which is evaluating Yucca Mountain, Nevada, as a potential high-level radioactive waste repository site

  5. Comparative study of cerium (IV) sorptive properties in zeolite Y and clinoptilolite; Estudio comparativo de la fijacion de cerio (IV) en zeolitas, faujasita-Y y clinoptilolita

    Energy Technology Data Exchange (ETDEWEB)

    Garcia D, O C

    1994-12-31

    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).

  6. 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)

  7. 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"-"1min"-"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"3Kg"-1 with R"2= 0.9789 for ZGuayNa, and K_p= 3.1 m"3Kg"-1 for ZGuayThio with R"2= 0.78. Finally, the capacity of the column system

  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. Removal of ammonium ion from aqueous solution using natural Turkish clinoptilolite

    International Nuclear Information System (INIS)

    Karadag, Dogan; Koc, Yunus; Turan, Mustafa; Armagan, Bulent

    2006-01-01

    A study on ion exchange kinetics and equilibrium isotherms of ammonium ion on natural Turkish clinoptilolite (zeolite) was conducted using a batch experiment technique. The effects of relevant parameters, such as temperature, contact time and initial ammonium (NH 4 + ) concentration were examined, respectively. The pseudo first-order, pseudo second-order kinetic models and intraparticle diffusion model were used to describe the kinetic data. The pseudo second-order kinetic model provided excellent kinetic data fitting (R 2 > 0.990) and intraparticle diffusion effects ammonium uptake. The Langmuir and Freundlich models were applied to describe the equilibrium isotherms for ammonium uptake and the Langmuir model agrees very well with experimental data. Thermodynamic parameters such as change in free energy (ΔG 0 ), enthalpy (ΔH 0 ) and entropy (ΔS 0 ) were also determined. An examination of the thermodynamic parameters shows that the exchange of ammonium ion by clinoptilolite is a process occurring spontaneously and physical in nature at ambient conditions (25 deg. C). The process is also found to be exothermic. The results indicate that there is a significant potential for the natural Turkish clinoptilolite as an adsorbent material for ammonium removal from aqueous solutions

  11. 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

  12. A Systematic Study on the Effect of Desilication of Clinoptilolite Zeolite on its Deep-Desulfurization Characteristics

    Directory of Open Access Journals (Sweden)

    Rahman Mahmoudi

    2016-07-01

    Full Text Available Natural clinoptilolite zeolite (CLP in its original or metal ion- exchanged form (Ni2+ is a weak adsorbent for relatively large thiophene derivative molecules like benzothiophene (BT and di-benzothiophene (DBT, due to its rather restricted micro-channel structure. A novelty of this work is that upon desilication treatments, it is possible to enhance the adsorption behavior of Ni2+-exchanged CLP for such large sulfur- containing molecules. A natural CLP zeolite has been desilicated using NaOH solutions in a concentration range of 0.2-2.0 M. The resulting powders have been subjected to XRF, XRD, FTIR, nitrogen adsorption/desorption, TEM and TGA analyses. The adsorption isotherms for the removal of thiophene (TP, BT, DBT and iso-propyl mercaptan (IPM have been obtained experimentally at 20 °C from simulated liquid fuels using iso-octane as solvent. The sample treated with 1.5 M NaOH solution showed the most significant enhancement in adsorptive properties. The selectivity order is IPM > TP > BT > DBT. Regenerability tests show a quasi constant adsorption capacity after the first cycle. The observed phenomena have been thoroughly discussed based on the physico-chemical analyses of the samples.

  13. Optimization of Manganese Reduction in Biotreated POME onto 3A Molecular Sieve and Clinoptilolite Zeolites.

    Science.gov (United States)

    Jami, Mohammed S; Rosli, Nurul-Shafiqah; Amosa, Mutiu K

    2016-06-01

    Availability of quality-certified water is pertinent to the production of food and pharmaceutical products. Adverse effects of manganese content of water on the corrosion of vessels and reactors necessitate that process water is scrutinized for allowable concentration levels before being applied in the production processes. In this research, optimization of the adsorption process conditions germane to the removal of manganese from biotreated palm oil mill effluent (BPOME) using zeolite 3A subsequent to a comparative adsorption with clinoptilolite was studied. A face-centered central composite design (FCCCD) of the response surface methodology (RSM) was adopted for the study. Analysis of variance (ANOVA) for response surface quadratic model revealed that the model was significant with dosage and agitation speed connoting the main significant process factors for the optimization. R(2) of 0.9478 yielded by the model was in agreement with predicted R(2). Langmuir and pseudo-second-order suggest the adsorption mechanism involved monolayer adsorption and cation exchanging.

  14. 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

  15. 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)

  16. 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.

  17. The removal of caesium ions using supported clinoptilolite

    International Nuclear Information System (INIS)

    De Haro-Del Rio, D.A.; Al-Joubori, S.; Kontogiannis, O.; Papadatos-Gigantes, D.; Ajayi, O.; Li, C.; Holmes, S.M.

    2015-01-01

    Highlights: • Natural clinoptilolite was supported over carbon structures produced from wastes. • Carbon–clinoptilolite showed an improved Cs + ions sorption capacity. • Overall kinetic rate was improved using carbon–clinoptilolite composite. • Diffusive resistances were modified using the composite and pure zeolite. • Final disposition volume can be reduced up to 60% by encapsulation. - Abstract: In this paper, the sorptive kinetic and diffusional characteristics of caesium ion removal from aqueous solution by carbon-supported clinoptilolite composites are presented. Natural clinoptilolite was supported on carbonaceous scaffolds prepared from date stones. Thermal treatment was applied to produce voids in the carbon which was conditioned using polydiallyldimethylammonium chloride to facilitate the clinoptilolite attachment. This method allowed the formation of a consistent zeolite layer on the carbon surface. The composite was applied in the removal of non-radioactive caesium ions showing an enhanced uptake from 55 mg g −1 to 120.9 mg g −1 when compared to clinoptilolite. Kinetic studies using Pseudo First Order model revealed an enhanced rate constant for carbon–clinoptilolite (0.0252 min −1 ) in comparison with clinoptilolite (0.0189 min −1 ). The Pseudo-First Order model described the process for carbon–clinoptilolite, meanwhile Pseudo Second Order model adjusted better for pure clinoptilolite. Diffusivity results suggested that mass transfer resistances involved in the Cs + sorption are film and intraparticle diffusion for natural clinoptilolite and intraparticle diffusion as the mechanism that controls the process for carbon–clinoptilolite composite. The most significant aspect being that the vitrified volume waste can be reduced by over 60% for encapsulation of the same quantity of caesium due to the enhanced uptake of zeolite

  18. Natural zeolites in diet or litter of broilers.

    Science.gov (United States)

    Schneider, A F; Almeida, D S De; Yuri, F M; Zimmermann, O F; Gerber, M W; Gewehr, C E

    2016-04-01

    This study aims to analyse the influence of adding natural zeolites (clinoptilolite) to the diet or litter of broilers and their effects on growth performance, carcass yield and litter quality. Three consecutive flocks of broilers were raised on the same sawdust litter, from d 1 to d 42 of age, and distributed in three treatments (control with no added zeolites, addition of 5 g/kg zeolite to diet and addition of 100 g/kg zeolites to litter). The addition of zeolites to the diet or litter did not affect growth performance or carcass yield. The addition of zeolites to the diet did not influence moisture content of the litter, ammonia volatilisation was reduced only in the first flock and pH of litter was reduced in the second and third flock. However, the addition of zeolites to the litter reduced moisture content, litter pH and ammonia volatilisation in all flocks analysed. The addition of 5 g/kg zeolite to the diet in three consecutive flocks was not effective in maintaining litter quality, whereas the addition of 100 g/kg natural zeolites to sawdust litter reduced litter moisture and ammonia volatilisation in three consecutive flocks raised on the same litter.

  19. Investigation of thermodynamic parameters of cetyl pyridinium bromide sorption onto ZSM-5 and natural clinoptilolite

    International Nuclear Information System (INIS)

    Ghiaci, M.; Kia, R.; Kalbasi, R.J.

    2004-01-01

    A study was undertaken to determine the influence of temperature and surfactant concentration on the adsorption of cetyl pyridinium bromide on two ZSM-5 zeolites, and on natural clinoptilolite. The effect of temperature on adsorption and thermodynamic properties was investigated by making measurements at (297, 303, 307, 313) K. The results show that the calculated curves from the general isotherm equation can represent the experimental data very well up to T=313 K. Based on the calculation of the thermodynamics of adsorption, it is evident that the principle contribution to the ΔG compfn hm of negative value is the large positive value of ΔS compfn hm (36 to 52 J · mol -1 ), whereas ΔH compfn hm is positive and in the range of 1 to 7 kJ · mol -1 . Therefore, similar to the micellisation in bulk solution, the second step of surfactant adsorption is an entropy-driven process

  20. 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.

  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. 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.

  3. 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

  4. ADSORPSI POLUTAN ION DIKROMAT MENGGUNAKAN ZEOLIT ALAM TERMODIFIKASI AMINA (Adsorption of Dichromate Ions Pollutant Using Ammine Modified-Natural Zeolites

    Directory of Open Access Journals (Sweden)

    Eko Sri Kunarti

    2015-11-01

    24,66 kJ/mol. ABSTRACT Chromium (VI is a heavy metal pollutant that is harmful to health and the environment, therefore Cr(VI ions in aqueous solution removal is important to overcome the environmental pollution. Adsorption process is one of simple techniques that can be used to take metal ions. Adsorption study of dichromate ions as a wastewater model of Cr(VI has been conducted in this research by using ammine modified natural zeolite as adsorbents. The research was initiated by preparation of adsorbent of ammine-modified natural zeolites. The preparation was started by washing the natural zeolite (Z using distilled water and refluxing by 3M hydrochloric acid. Refluxed zeolites (ZA were modified by a quaternary ammonium salt, N-cethyl-N,N,N-trimethylammonium bromide (CTAB, and a primary amine, propylamine (PA. The natural zeolite (Z, acid activated zeolite (ZA and amine-modified zeolites were then applied for adsorption of dichromate ions. Characterization of zeolite samples was performed by infrared spectroscopy and X-ray diffraction methods to confirm the crystal structure, and atomic absorption spectroscopy method to analyze the adsorbed dichromate ions. Results showed that all zeolite samples contain clinoptilolite, mordernite and quartz minerals. The zeolite structure was not changed by heat and chemical treatments. Modification of zeolites enhanced the adsorption efficiency of natural zeolites. The dichromate ions were better adsorbed on ammine modified-zeolites compared to that of unmodified-zeolite with adsorption ability of CTAB modified zeolite (CTAB-Z was greater than that of propylammine modified zeolite (PA-Z. The adsorption of dichromate on zeolite samples was achieved in the order of CTAB-Z > PA-Z > ZA > Z, with the adsorption efficiency was about 1.96; 1.74; 0.90 and 0.48 mg/g, respectively. The dichromate ions adsorption by CTAB modified zeolite is chemical adsorption (chemisorption with the adsorption energy of 24.66 kJ/mol.

  5. 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)

  6. 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.

  7. The influence of pH on the adsorption of lead by Na-clinoptilolite ...

    African Journals Online (AJOL)

    2011-09-28

    Sep 28, 2011 ... Adsorption of heavy metals by clinoptilolite, the most used natural zeolite found in ... dehydrated ionic radius and the electric charge of ions. So, the ... ionic radii have high dehydration energy, thus affecting Step. (iv). Generally ...

  8. 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

  9. Copper removal and nickel for exchange cationic with a natural zeolite

    International Nuclear Information System (INIS)

    Estupinan, Arnoldy; Sarmiento, Diego; Belalcazar de Galvis, Ana Maria

    1998-01-01

    Natural zeolite clinoptilolite, was used to remove copper and nickel from waste waters of a galvanotechnical company. Exchange capacity determined for the zeolite after its transformation to homoionic sodium form, was 0.794 meq/g for copper and 0.447 meq/g for nickel. There were made batch and column experiments, reaching the last one a better approach to the equilibrium. From the degeneration essays, the sodical zeolite concentrates the copper in the waste waters to 23.5 up times the level found for the acid rinsing waters; it shows its potential use in treatment of these waste, because its effectiveness and low cost

  10. 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

  11. 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

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

    Science.gov (United States)

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

    2014-06-15

    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 823K 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 623K, 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. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Characterization of modified clinoptilolite

    International Nuclear Information System (INIS)

    Novosad, J.; Jandl, J.; Woollins, J.D.

    1992-01-01

    Samples of clinoptilolite were modified using insoluble hexacyanoferrate from aqueous solution. The modified samples were characterized by elemental analysis, powder X-ray diffraction, solid state NMR and vibrational spectroscopy. The sorption properties of modified clinoptilolite were studied, too. Higher affinity for 137 Cs sorption in comparison with the natural clinoptilolite has been proved. (author) 5 refs.; 3 figs.; 2 tabs

  14. Application of nonlinear regression analysis for ammonium exchange by natural (Bigadic) clinoptilolite

    International Nuclear Information System (INIS)

    Gunay, Ahmet

    2007-01-01

    The experimental data of ammonium exchange by natural Bigadic clinoptilolite was evaluated using nonlinear regression analysis. Three two-parameters isotherm models (Langmuir, Freundlich and Temkin) and three three-parameters isotherm models (Redlich-Peterson, Sips and Khan) were used to analyse the equilibrium data. Fitting of isotherm models was determined using values of standard normalization error procedure (SNE) and coefficient of determination (R 2 ). HYBRID error function provided lowest sum of normalized error and Khan model had better performance for modeling the equilibrium data. Thermodynamic investigation indicated that ammonium removal by clinoptilolite was favorable at lower temperatures and exothermic in nature

  15. Thermal expansion of ceramic samples containing natural zeolite

    Science.gov (United States)

    Sunitrová, Ivana; Trník, Anton

    2017-07-01

    In this study the thermal expansion of ceramic samples made from natural zeolite is investigated. Samples are prepared from the two most commonly used materials in ceramic industry (kaolin and illite). The first material is Sedlec kaolin from Czech Republic, which contains more than 90 mass% of mineral kaolinite. The second one is an illitic clay from Tokaj area in Hungary, which contains about 80 mass% of mineral illite. Varying amount of the clay (0 % - 50 %) by a natural zeolite from Nižný Hrabovec (Slovak Republic), containing clinoptilolite as major mineral phase is replaced. The measurements are performed on cylindrical samples with a diameter 14 mm and a length about 35 mm by a horizontal push - rod dilatometer. Samples made from pure kaolin, illite and zeolite are also subjected to this analysis. The temperature regime consists from linear heating rate of 5 °C/min from 30 °C to 1100 °C. The results show that the relative shrinkage of ceramic samples increases with amount of zeolite in samples.

  16. 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

    Science.gov (United States)

    2012-01-01

    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 form)that 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 zeolite treatment had a positive effect on performance production and organoleptic parameters that were measured and mainly on the increase level of Omega 3 fatty acid. 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. PMID:22394592

  17. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Yang; Shapter, Joseph G. [Flinders Centre for Nanoscale Science and Technology, School of Chemical and Physical Sciences, Flinders University, Sturt Road, Bedford Park, Adelaide 5042, SA (Australia); Popelka-Filcoff, Rachel [School of Chemical and Physical Sciences, Flinders University, Sturt Road, Bedford Park, Adelaide 5042, SA (Australia); Bennett, John W. [Centre for Nuclear Applications, Australian Nuclear Science and Technology Organisation, Lucas Heights 2234, NSW (Australia); Ellis, Amanda V., E-mail: Amanda.Ellis@flinders.edu.au [Flinders Centre for Nanoscale Science and Technology, School of Chemical and Physical Sciences, Flinders University, Sturt Road, Bedford Park, Adelaide 5042, SA (Australia)

    2014-05-01

    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{sup −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{sup −1} for pristine natural zeolite and 28.58 mg g{sup −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.

  19. Determination of 60Co sorption in natural clinoptilolite

    International Nuclear Information System (INIS)

    Hernandez B, E.; Granados C, F.

    1997-01-01

    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 2 solution marked with 60 Co at p H 6.5 in different contact times. It was observed a maximum sorption of 0.408 m eq Co +2 /g mineral, from 0.314 m eq Co +2 /g mineral correspond at ion exchange. (Author)

  20. 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.

  1. 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

  2. Separation of cesium and strontium with zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Kanno, T; Hashimoto, H [Tohoku Univ., Sendai (Japan). Research Inst. of Mineral Dressing and Metallurgy

    1976-06-01

    The basic studies of separation of cesium and strontium were made with specimens of zeolite, which are synthetic zeolites A, X and Y; synthetic mordenite; natural mordenite; and clinoptilolite. Ammonium chloride was used as eluent, because it was considered to be a most appropriate eluent in alkaline chlorides. Cesium was easily eluted from the zeolites A and X by ammonium chloride solution, but it was difficult to elute from the synthetic mordenite, natural mordenite and clinoptilolite by ammonium chloride solution, but it was difficult to elute from the zeolites A and X. The zeolite Y is the only one zeolite among these zeolites from which both of cesium and strontium were easily eluted by ammonium chloride solution. Strontium could be separated from cesium with zeolites by formation of Sr-EDTA chelate at pH above 11. In this process, cesium was only exchanged in zeolite column, but strontium flow out from it.

  3. Separation of cesium and strontium with zeolites

    International Nuclear Information System (INIS)

    Kanno, Takuji; Hashimoto, Hiroyuki

    1976-01-01

    The basic studies of separation of cesium and strontium were made with specimens of zeolite, which are synthetic zeolites A, X and Y; synthetic mordenite; natural mordenite; and clinoptilolite. Ammonium chloride was used as eluent, because it was considered to be a most appropriate eluent in alkaline chlorides. Cesium was easily eluted from the zeolites A and X by ammonium chloride solution, but it was difficult to elute from the synthetic mordenite, natural mordenite and clinoptilolite by ammonium chloride solution, but it was difficult to elute from the zeolites A and X. The zeolite Y is the only one zeolite among these zeolites from which both of cesium and strontium were easily eluted by ammonium chloride solution. Strontium could be separated from cesium with zeolites by formation of Sr-EDTA chelate at pH above 11. In this process, cesium was only exchanged in zeolite column, but strontium flow out from it. (auth.)

  4. Ultrasound-assisted dispersive solid phase extraction of cadmium(II) and lead(II) using a hybrid nanoadsorbent composed of graphene and the zeolite clinoptilolite

    International Nuclear Information System (INIS)

    Ghazaghi, Mehri; Mousavi, Hassan Zavvar; Shirkhanloo, Hamid; Rashidi, Ali Morad

    2015-01-01

    We describe a hybrid nanoadsorbent prepared by depositing graphene on the zeolite clinoptilolite by chemical vapor deposition. The resulting sorbent is well suited for the preconcentration of lead(II) and cadmium(II) by ultrasound-assisted dispersive micro solid–phase extraction. An extraction unit has been designed and manufactured that facilitates handling of small sample volumes. The effects of sample pH, amount of sorbent, concentration and volume of elution and time of ultrasonic bath were investigated. The nanoadsorbent was characterized by scanning electron microscopy, X-ray diffraction and energy dispersive X-ray microanalysis, all of which revealed the high surface area of the graphene sheets on the clinoptilolite. The extraction recoveries when using the new nanoadsorbent are 97 % (as opposed to a mere 10 % in case of clinoptilolite only). It is assumed that the graphene sheets located around the porous structure of clinoptilolite are acting as a barrier against macromolecules potentially existing in the sample matrices. The method was applied to the determination of lead and cadmium in water and human serum samples by electrothermal atomic absorption spectrometry. The detection limits were as low as 70 and 4 ng L −1 for Pb(II) and Cd(II), respectively. The accuracy of the method was underpinned by correct analysis of a standard reference material (SRM: 203105 Seronorm Trace Elements Serum L-2). (author)

  5. Ion exchange and dehydration effects on potassium and argon contents of clinoptilolite

    International Nuclear Information System (INIS)

    WoldeGabriel, G.; Levy, S.

    1995-01-01

    Zeolite-rich Miocene tuffs are an important part of the principal hydrochemical barrier to water-borne radionuclide transport from a potential high-level nuclear waste repository at Yucca Mountain, Nevada. The timing of zeolitization is an issue that relates to paleohydrology, permeability, zeolite stability, and unsaturated-zone geochemical processes. Exploratory K/Ar dating of clinoptilolite, the most abundant and widespread zeolite, shows a striking and consistent pattern of increasing apparent ages (2-13 Ma) with depth. Only the isotopic ages from the saturated zone are compatible with geologic evidence suggesting an age >10 Ma for most of the zeolites. Factors that may be responsible for the young apparent ages in the unsaturated zone were investigated. Cation exchange with recharge water and Ar diffusion under unsaturated conditions (processes that may be characteristic of the unsaturated zone) were evaluated experimentally for their effects on K/Ar systematics. Cation exchanging a natural clinoptilolite with Ca-, Cs-, K-, and Na- chloride solutions showed minimal effects on radiogenic Ar content. However, clinoptilolite heated at 200 degrees C for 16 hours in air lost a significant amount of its radiogenic Ar compared with minimal losses from clinoptilolite heated in water at 100 degrees C for over 5 months. The preliminary results indicate that Ar loss from incompletely hydrated clinoptilolite may be a major factor contributing to the young apparent ages of clinoptilolite in the unsaturated zone at Yucca Mountain

  6. 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)

  7. Zeolite: "the magic stone: main nutritional, environmental, experimental and clinical fields of application

    OpenAIRE

    Laurino, Carmen; Palmieri, Beniamino

    2015-01-01

    Introduction: zeolites (clinoptilolites) are a family of alluminosilicates and cations clustered to form macro aggregates by small individual cavities. In the medical area they are involved in detoxification mechanisms capturing ions and molecules into their holes. Actually, we classify about 140 types of natural and 150 synthetic zeolites, for specific and selective use. Clinoptilolite is a natural zeolite and it is the most widespread compound in the medical market. Objective: this review a...

  8. 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)

  9. 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.

  10. Ozone decomposition on Ag/SiO2 and Ag/clinoptilolite catalysts at ambient temperature

    International Nuclear Information System (INIS)

    Nikolov, Penko; Genov, Krassimir; Konova, Petya; Milenova, Katya; Batakliev, Todor; Georgiev, Vladimir; Kumar, Narendra; Sarker, Dipak K.; Pishev, Dimitar; Rakovsky, Slavcho

    2010-01-01

    Silver modified zeolite (Bulgarian natural clinoptilolite) and Ag/silica catalysts were synthesized by ion exchange and incipient wet impregnation method respectively and characterized by different techniques. DC arc-AES was used for Ag detection. XRD spectra show that Ag is loaded over the surface of the SiO 2 sample and that after the ion-exchange process the HEU type structure of clinoptilolite is retained. UV-VIS (specific reflection at 310 nm) and IR (band at 695 cm -1 ) spectroscopy analysis proved that silver is loaded as a T-atom into zeolite channels as Ag + , instead of Na + , Ca 2+ , or K + ions, existing in the natural clinoptilolite form. The samples Ag/SiO 2 and Ag-clinoptilolite were tested as catalysts for decomposition of gas phase ozone. Very high catalytic activity (up to 99%) was observed and at the same time the catalysts remained active over time at room temperature.

  11. 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

  12. 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

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

    International Nuclear Information System (INIS)

    Rehakova, Maria; Fortunova, Lubica; Bastl, Zdenek; Nagyova, Stanislava; Dolinska, Silvia; Jorik, Vladimir; Jona, Eugen

    2011-01-01

    Zeoadsorbents on the basis of copper forms of synthetic zeolite ZSM5 and natural zeolite of the clinoptilolite type (CT) have been studied taking into account their environmental application in removing harmful pyridine (py) from liquid and gas phase. Sorption of pyridine by copper forms of zeolites (Cu-ZSM5 and Cu-CT) has been studied by CHN, X-ray photoelectron spectroscopy, X-ray powder diffractometry, FTIR spectroscopy, thermal analysis (TG, DTA and DTG) and analysis of the surface areas and the pore volumes by low-temperature adsorption of nitrogen. The results of thermal analyses of Cu-ZSM5, Cu-(py) x ZSM5, Cu-CT and Cu-(py) x CT zeolitic products with different composition (x depends on the experimental conditions of sorption of pyridine) clearly confirmed their different thermal properties as well as the sorption of pyridine. In the zeolitic pyridine containing samples the main part of the pyridine release process occurs at considerably higher temperatures than is the boiling point of pyridine, which proves strong bond and irreversibility of py-zeolite interaction. FTIR spectra of Cu-(py) x zeolite samples showed well resolved bands of pyridine. The results of thermal analysis and FTIR spectroscopy are in a good agreement with the results of other used methods.

  14. The effect of feed supplementation with Zakarpacki zeolite (clinoptilolite) on percentages of T and B lymphocytes and cytokine concentrations in poultry.

    Science.gov (United States)

    Jarosz, Lukasz; Stepien-Pysniak, Dagmara; Gradzki, Zbigniew; Kapica, Malgorzata; Gacek, Agata

    2017-07-01

    The available literature lacks information on the effect of Zakarpacki zeolite (clinoptilolite) on the immune system of poultry. Therefore, the aim of this study was to determine the effect of this zeolite on selected indicators of the immune response in poultry by evaluating the expression of cluster of differentiation (CD) surface molecules on T and B lymphocytes and the concentration of IL-2 and IL-10 in the blood. Ninety one-day-old Ross 308 broiler chicks were used in the study. The birds were divided into 3 groups of 30 each. The same basic diet was used in all groups, but groups II and III received a feed additive in the form of 2% and 3% zeolite. Blood samples were collected from all birds on the 40th day of observations. Weight gain in the birds in both experimental groups was significantly higher, and no clinical symptoms of disease were observed. The percentage of CD4+CD25+ T and B lymphocytes was higher in both groups receiving zeolite, but the percentage of CD8+CD25+ T lymphocytes was higher only in the group receiving 3% zeolite. There were no differences between the groups in the percentage of cells with CD3+ and MHC Class II expression. Higher serum concentrations of IL-2 and IL-10 were noted only in group III. The use of zeolites enhances antigen presentation and leads to increased Th1 and Th2 response. Excessive supply of zeolite in the feed leads to a local inflammatory response, which may cause damage to the intestinal barrier. © 2017 Poultry Science Association Inc.

  15. Synthesis of high capacity cation exchangers from a low-grade Chinese natural zeolite

    International Nuclear Information System (INIS)

    Wang Yifei; Lin Feng

    2009-01-01

    The Chinese natural zeolite, in which clinoptilolite coexists with quartz was treated hydrothermally with NaOH solutions, either with or without fusion with NaOH powder as pretreatment. Zeolite Na-P, Na-Y and analcime were identified as the reacted products, depending on the reaction conditions such as NaOH concentration, reaction time and hydrothermal temperature. The products were identified by X-ray diffraction, and characterized by Fourier transform IR and ICP. With hydrothermal treatment after fusion of natural zeolite with NaOH, high purity of zeolite Na-Y and Na-P can be selectively formed, their cation exchange capacity (CEC) are 275 and 355 meq/100 g respectively, which are greatly higher than that of the natural zeolite (97 meq/100 g). Furthermore, the ammonium removal by the synthetic zeolite Na-P in aqueous solution was also studied. The equilibrium isotherms have been got and the influence of other cations present in water upon the ammonia uptake suggested an order of preference Ca 2+ > K + > Mg 2+ .

  16. 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.

  17. 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

  18. Transformation of Indonesian Natural Zeolite into Analcime Phase under Hydrothermal Condition

    Science.gov (United States)

    Lestari, W. W.; Hasanah, D. N.; Putra, R.; Mukti, R. R.; Nugrahaningtyas, K. D.

    2018-04-01

    Natural zeolite is abundantly available in Indonesia and well distributed especially in the volcano area like Java, Sumatera, and Sulawesi. So far, natural zeolite from Klaten, Central Java is one of the most interesting zeolites has been widely studied. This research aims to know the effect of seed-assisted synthesis under a hydrothermal condition at 120 °C for 24 hours of Klaten’s zeolite toward the structural change and phase transformation of the original structure. According to XRD and XRF analysis, seed-assisted synthesis through the addition of aluminosilicate mother solution has transformed Klaten’s zeolite which contains (mordenite and clinoptilolite) into analcime type with decreasing Si/Al ratio from 4.51 into 1.38. Morphological analysis using SEM showed the shape changes from irregular into spherical looks like takraw ball in the range of 0.3 to 0.7 micrometer. Based on FTIR data, structure of TO4 site (T = Si or Al) was observed in the range of 300-1300 cm-1 and the occupancy of Brønsted acid site as OH stretching band from silanol groups was detected at 3440-3650 cm-1. Nitrogen adsorption-desorption analysis confirmed that transformation Klaten’s zeolite into analcime type has decreased the surface area from 55.41 to 22.89 m2/g and showed inhomogeneous pore distribution which can be classified as micro-mesoporous aluminosilicate materials.

  19. Aflatoxin B1 adsorption by the natural aluminosilicates - concentrate of montmorillonite and zeolite

    Directory of Open Access Journals (Sweden)

    Marković Marija A.

    2016-01-01

    Full Text Available Aflatoxin B1 adsorption by the concentrate of bentonite clay - montmorillonite and the natural zeolite - clinoptilolite and was investigated at the initial toxin concentration 4 ppm, with different amonunts of solid phase in suspension (10, 5, 2 and 1 mg/10 mL and different pH values - 3, 7 and 9. Results indicated that for both minerals, decreasing the amount of solid phase in suspension, decrease the amount of active sites relevant for adsorption of aflatoxin B1. Thus, for concentrate of montnorillonite, at the lowest level of solid phase in suspension (1 mg/10 mL, aflatoxin B1 adsorption indexes were 97% at pH 3, 88% at pH 7 and 82% at pH 9, while for the natural zeolite, adsorption of toxin was 9% at pH 3 and 7% at pH 7 and 9. Since inorganic cations in minerals are mainly responsible for aflatoxin B1 adsorption, even the natural zeolite - clinoptilite has much higher cation exchange capacity (the content of inorganic exchangeable cations compared to the concentrate of montmorillonite, adsorption of aflatoxin B1 by this mineral is much lower. Comparing the molecular dimensions of aflatoxin B1 molecule with the dimension of channels of clinoptilolite and interlamellar space of montmorillonite it is obvious that this toxin is adsorbed only at the external surface of clinoptilolite while in the montmorillonite all active sites are equally available for its adsorption. Thus, the concentrate of montmorillonite posess by higher adsorption capacity for aflatoxin B1. Results presented in this paper confirmed the fact the differences in the structure of minerals led to their different efficiency for adsorption of aflatoxin B1. Mineralogical and chemical composition, determination of cation exchange capacity, etc., are very important parameters influencing the effectiveness of minerals as aflatoxin B1 adsorbents. [Projekat Ministarstva nauke Republike Srbije, br. 451-03-2802-IP Tip1/142, br. 172018 i br. 34013

  20. 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.

  1. 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...

  2. 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.

  3. 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)

  4. Removal of lead from aqueous solutions by using the natural and Fe(III)-modified zeolite

    International Nuclear Information System (INIS)

    Kragović, Milan; Daković, Aleksandra; Sekulić, Živko; Trgo, Marina; Ugrina, Marin; Perić, Jelena; Gatta, G. Diego

    2012-01-01

    In the present study, the sorption of lead by the natural and Fe(III)-modified zeolite (clinoptilolite) is described. The characterization of the natural zeolite-rich rock and the Fe(III)-modified form was performed by chemical analysis, point of the zero charge (pH pzc ), X-ray powder diffraction, applying the Rietveld/RIR method for the quantitative phase analysis, and scanning electron microscopy. The effects of sorbents dose and the initial lead concentrations on its sorption by two sorbents were investigated. For both sorbents, it was determined that at lower initial concentrations of lead, ion exchange of inorganic cations in zeolites with lead, together with uptake of hydrogen dominated, while at higher initial lead concentrations beside these processes, chemisorption of lead occurred. Significantly higher sorption of lead was achieved with Fe(III)-modified zeolite. From sorption isotherms, maximum sorbed amounts of lead, under the applied experimental conditions, were 66 mg/g for the natural and 133 mg/g for Fe(III)-modified zeolite. The best fit of experimental data was achieved with the Freundlich model (R 2 ≥ 0.94).

  5. Photodynamic dye adsorption and release performance of natural zeolite

    OpenAIRE

    Hovhannisyan, Vladimir; Dong, Chen-Yuan; Chen, Shean-Jen

    2017-01-01

    Clinoptilolite type of zeolite (CZ) is a promising material for biomedicine and pharmaceutics due to its non-toxicity, thermal stability, expanded surface area, and exceptional ability to adsorb various atoms and organic molecules into micropores. Using multiphoton microscopy, we demonstrated that individual CZ particles produce two-photon excited luminescence and second harmonic generation signal at femtosecond laser excitation, and adsorb photo-dynamically active dyes such as hypericin and ...

  6. 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.

  7. 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

  8. ADSORPTION MALACHITE GREEN ON NATURAL ZEOLITE

    OpenAIRE

    Eko Ariyanto

    2012-01-01

    A natural zeolite was employed as adsorbent for reducing of malachite green from aqueous solution. A batch system was applied to study the adsorption of malachite green in single system on natural zeolite. The adsorption studies indicate that malachite green in single component system follows the second-order kinetics and the adsorption is diffusion process with two stages for malachite green. Malachite green adsorption isotherm follows the Langmuir model.

  9. ADSORPTION MALACHITE GREEN ON NATURAL ZEOLITE

    Directory of Open Access Journals (Sweden)

    Eko Ariyanto

    2012-02-01

    Full Text Available A natural zeolite was employed as adsorbent for reducing of malachite green from aqueous solution. A batch system was applied to study the adsorption of malachite green in single system on natural zeolite. The adsorption studies indicate that malachite green in single component system follows the second-order kinetics and the adsorption is diffusion process with two stages for malachite green. Malachite green adsorption isotherm follows the Langmuir model.

  10. 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)

  11. Synthesis of Zeolite NaA from Low Grade (High Impurities) Indonesian Natural Zeolite

    OpenAIRE

    Mustain, Asalil; Wibawa, Gede; Nais, Mukhammad Furoiddun; Falah, Miftakhul

    2014-01-01

    The zeolite NaA has been successfully synthesized from the low grade natural zeolite with high impurities. The synthesis method was started by mixing natural zeolite powder with NH4Cl aqueous solution in the reactor as pretreatment. The use of pretreatment was to reduce the impurities contents in the zeolite. The process was followed by alkaline fusion hydrothermal treatment to modify the framework structure of natural zeolite and reduce the SiO2/Al2O3 ratio. Finally, the synthesized zeolite ...

  12. 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.

  13. 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)

  14. Hydrogen Adsorption in Zeolite Studied with Sievert and Thermogravimetric Methods

    International Nuclear Information System (INIS)

    Lesnicenoks, P; Sivars, A; Grinberga, L; Kleperis, J

    2012-01-01

    Natural clinoptilolite (mixture from clinoptilolite, quartz and muscovite) is activated with palladium and tested for hydrogen adsorption capability at temperatures RT - 200°C. Thermogravimetric and volumetric methods showed that zeolite activated with palladium (1.25%wt) shows markedly high hydrogen adsorption capacity - up to 3 wt%. Lower amount of adsorbed hydrogen (∼1.5 wt%) was found for raw zeolite and activated with higher amount of palladium sample. Hypothesis is proposed that the heating of zeolite in argon atmosphere forms and activates the pore structure in zeolite material, where hydrogen encapsulation (trapping) is believed to occur when cooling down to room temperature. An effect of catalyst (Pd) on hydrogen sorption capability is explained by spillover phenomena were less-porous fractions of natural clinoptilolite sample (quartz and muscovite) are involved.

  15. 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.

  16. 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)

  17. 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

  18. 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

  19. 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

  20. Natural zeolites: characteristic, properties and uses

    International Nuclear Information System (INIS)

    Bosch, P.; Bulbulian, S.; Olguin, M. T.

    2011-01-01

    The zeolites are a crystalline aluminium silicates family of volcanic origin. It characterizes them a porous structure, nano metric, regular and homogeneous. Therefore, they turn out to be excellent molecular sieves besides exchangers of ions. This last property it has been extremely exploited, in order to retain the radioactive ions of the contaminated waters in the accident of Three Mile Island (USA), of Chernobyl (Russia) and Fukushima Daiichi (Japan). Nevertheless, the use of the zeolites goes but there ... these they can work as much as nutritional supplement for chickens and pigs, as well as for to retain odors or to separate gases. The construction industry has welcomed this mineral, when either using it as quarry or additive in the called pozzolanic cements. In this book the authors explain the zeolites formation in the nature, their structure and the main uses of these minerals that some authors have baptized as the magic rocks. (Author)

  1. 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.

  2. Natural zeolite reactivity towards ozone: the role of compensating cations.

    Science.gov (United States)

    Valdés, Héctor; Alejandro, Serguei; Zaror, Claudio A

    2012-08-15

    Among indoor pollutants, ozone is recognised to pose a threat to human health. Recently, low cost natural zeolites have been applied as alternative materials for ozone abatement. In this work, the effect of compensating cation content of natural zeolite on ozone removal is studied. A Chilean natural zeolite is used here as starting material. The amount of compensating cations in the zeolite framework was modified by ion exchange using an ammonium sulphate solution (0.1 mol L(-1)). Characterisation of natural and modified zeolites were performed by X-ray powder diffraction (XRD), nitrogen adsorption at 77K, elemental analysis, X-ray fluorescence (XRF), thermogravimetric analysis coupled with mass spectroscopy (TGA-MS), and temperature-programmed desorption of ammonia (NH(3)-TPD). Ozone adsorption and/or decomposition on natural and modified zeolites were studied by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Results show that the zeolite compensating cation content affects ozone interaction with zeolite active sites. Ammonium ion-exchange treatments followed by thermal out-gassing at 823 K, reduces ozone diffusion resistance inside the zeolite framework, increasing ozone abatement on zeolite surface active sites. Weak and strong Lewis acid sites of zeolite surface are identified here as the main active sites responsible of ozone removal. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. 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)

  4. Natural zeolite reactivity towards ozone: The role of compensating cations

    International Nuclear Information System (INIS)

    Valdés, Héctor; Alejandro, Serguei; Zaror, Claudio A.

    2012-01-01

    Highlights: ► Chemical and thermal treatment enhances catalytic activity of natural zeolite. ► Modified natural zeolite exhibits high stability after thermal treatment. ► Reducing the compensating cation content leads to an increase on ozone abatement. ► Surface active atomic oxygen was detected using the DRIFT technique. ► The highest reactivity toward ozone was performed by NH4Z3 zeolite sample. - Abstract: Among indoor pollutants, ozone is recognised to pose a threat to human health. Recently, low cost natural zeolites have been applied as alternative materials for ozone abatement. In this work, the effect of compensating cation content of natural zeolite on ozone removal is studied. A Chilean natural zeolite is used here as starting material. The amount of compensating cations in the zeolite framework was modified by ion exchange using an ammonium sulphate solution (0.1 mol L −1 ). Characterisation of natural and modified zeolites were performed by X-ray powder diffraction (XRD), nitrogen adsorption at 77 K, elemental analysis, X-ray fluorescence (XRF), thermogravimetric analysis coupled with mass spectroscopy (TGA-MS), and temperature-programmed desorption of ammonia (NH 3 -TPD). Ozone adsorption and/or decomposition on natural and modified zeolites were studied by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Results show that the zeolite compensating cation content affects ozone interaction with zeolite active sites. Ammonium ion-exchange treatments followed by thermal out-gassing at 823 K, reduces ozone diffusion resistance inside the zeolite framework, increasing ozone abatement on zeolite surface active sites. Weak and strong Lewis acid sites of zeolite surface are identified here as the main active sites responsible of ozone removal.

  5. Natural zeolite reactivity towards ozone: The role of compensating cations

    Energy Technology Data Exchange (ETDEWEB)

    Valdes, Hector, E-mail: hvaldes@ucsc.cl [Laboratorio de Tecnologias Limpias (F. Ingenieria), Universidad Catolica de la Santisima Concepcion, Alonso de Ribera 2850, Concepcion (Chile); Alejandro, Serguei; Zaror, Claudio A. [Departamento de Ingenieria Quimica (F. Ingenieria), Universidad de Concepcion, Concepcion (Chile)

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer Chemical and thermal treatment enhances catalytic activity of natural zeolite. Black-Right-Pointing-Pointer Modified natural zeolite exhibits high stability after thermal treatment. Black-Right-Pointing-Pointer Reducing the compensating cation content leads to an increase on ozone abatement. Black-Right-Pointing-Pointer Surface active atomic oxygen was detected using the DRIFT technique. Black-Right-Pointing-Pointer The highest reactivity toward ozone was performed by NH4Z3 zeolite sample. - Abstract: Among indoor pollutants, ozone is recognised to pose a threat to human health. Recently, low cost natural zeolites have been applied as alternative materials for ozone abatement. In this work, the effect of compensating cation content of natural zeolite on ozone removal is studied. A Chilean natural zeolite is used here as starting material. The amount of compensating cations in the zeolite framework was modified by ion exchange using an ammonium sulphate solution (0.1 mol L{sup -1}). Characterisation of natural and modified zeolites were performed by X-ray powder diffraction (XRD), nitrogen adsorption at 77 K, elemental analysis, X-ray fluorescence (XRF), thermogravimetric analysis coupled with mass spectroscopy (TGA-MS), and temperature-programmed desorption of ammonia (NH{sub 3}-TPD). Ozone adsorption and/or decomposition on natural and modified zeolites were studied by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Results show that the zeolite compensating cation content affects ozone interaction with zeolite active sites. Ammonium ion-exchange treatments followed by thermal out-gassing at 823 K, reduces ozone diffusion resistance inside the zeolite framework, increasing ozone abatement on zeolite surface active sites. Weak and strong Lewis acid sites of zeolite surface are identified here as the main active sites responsible of ozone removal.

  6. High performance nano-titania photocatalytic paper composite. Part II: Preparation and characterization of natural zeolite-based nano-titania composite sheets and study of their photocatalytic activity

    International Nuclear Information System (INIS)

    Ko, Seonghyuk; Fleming, Paul D.; Joyce, Margaret; Ari-Gur, Pnina

    2009-01-01

    A novel paper composite with high photocatalytic performance was fabricated using natural zeolite (clinoptilolite)-based nanosized TiO 2 . Photocatalytic materials, from sol-gel derived TiO 2 colloids to its coupling with zeolite, have been designed, prepared and characterized. As-prepared anatase TiO 2 on zeolite particles were readily used in photocatalytic paper, which revealed zeolite-TiO 2 particles dispersed on a dense network of fibers with microvoids. Natural zeolite-based TiO 2 composite sheets described here decomposed gaseous toluene very effectively after UV irradiation and its removal efficiency was higher than that accomplished by photocatalytic paper made with Degussa P25 TiO 2 or Ahlstrom commercial photocatalytic non-woven paper.

  7. Photocatalytic removal of SO2 using natural zeolite modified by TiO2 and polyoxypropylene surfactant.

    Science.gov (United States)

    Amini, Nasibeh; Soleimani, Mohsen; Mirghaffari, Nourollah

    2018-01-25

    Air pollution due to emission of various hazardous gases such as SO 2 into the atmosphere and its control is an important environmental issue. Application of photocatalysts is considered as a suitable process to control the gaseous pollutants. In this study, the efficiency of clinoptilolite as a natural zeolite (Ze) modified by TiO 2 (Ze-Ti) and a polymeric surfactant polyoxypropylene (Ze-Ti-POP) for removal of SO 2 was investigated. The nanocomposites were characterized by SEM, EDX, and BET analyses. The photocatalytic oxidation experiments of SO 2 by the nanocomposites and natural zeolite were done under UV irradiation with initial SO 2 concentration of 500 ppm in a photoreactor. The effects of different factors including reaction time, catalyst dose, UV irradiation intensity, humidity content, and calcination temperature and dose of TiO 2 were studied. The modification of clinoptilolite by TiO 2 and POP increased considerably the BET specific surface area of the nanocomposites. The results showed that maximum removal efficiencies of SO 2 by Ze-Ti and Ze-Ti-POP under the optimum experimental conditions were 82.1 and 87.4%, respectively. Adsorption kinetics data well fitted with the Langmuir-Hinshelwood model. Moreover, reusing of nanocomposites after three regeneration cycles indicated that application of Ze-Ti and Ze-Ti-POP nanocomposites could be a promising approach for SO 2 removal. Graphical abstract ᅟ.

  8. 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.

  9. 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.)

  10. 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

  11. Ion Exchange Properties of Georgian Natural Zeolites

    Directory of Open Access Journals (Sweden)

    Vladimer Tsitsishvili

    2017-06-01

    Full Text Available Ion-exchange properties of natural zeolites of Georgia with a relatively low Si/Al ratio have been studied: analcimes are characterized by selectivity series: Na+>K+>Ag+>NH4+>Ca+2>Sr+2>Li+; for phillipsites selectivity sequences are different for calcium- and potassium forms; selectivity sequence for scolecite is: Sr+2>Ba+2>Rb+>Ca+2>Cs+>K+>NH4+>Na+>Mg+2>Li+>Cd+2>Cu+2> Mn+2> Zn+2>Co+2>Ni+2.

  12. 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

  13. Removal of uranium ions from synthetic wastewater using ZnO/Na-clinoptilolite nanocomposites

    International Nuclear Information System (INIS)

    Aghadavoud, Azadeh; Saraee, Khadijeh Rezaee Ebrahim; Shakur, Hamid Reza; Sayyari, Rasol

    2016-01-01

    Uranium is one of the heavy metals that is found in industrial wastewater and is very toxic for human and environment. In this work, natural clinoptilolite is used as a low-cost adsorbent for uranium removal from aqueous solutions. The sodium form of clinoptilolite and ZnO/Na-clinoptilolite nanocomposite were prepared. The sample sorption capacities for uranium removal from simulated drinking water in the presence of other anions and cations were investigated. Natural zeolite and its modified forms were characterized by XRD, XRF, FTIR, TEM and BET. Batch experiments were used to determine the best adsorption conditions. The effects of various parameters such as contact time, pH, initial uranium concentration, temperature and mass sorbent on the removal efficiency of uranium ions were studied. The equilibration was attained after 2 and 6 h for the Na-clinoptilolite and ZnO/Na-clinoptilolite nanocomposite, respectively. Both adsorbents showed relatively fast adsorption. Effective removal of uranium was demonstrated at pH values of 4-8 for both forms of zeolite. Temperature had no significant effect on adsorption. The maximum removal efficiency of uranium by the ZnO/Na-clinoptilolite nanocomposite in pH=7.2 and room temperature was 98.55%. Langmuir, Freundlich and Sips models were used for describing the equilibrium isotherms for uranium uptake. The Sips model corresponded well with the experimental data. The thermodynamic parameters, such as ΔG , ΔH and ΔS , have been calculated and interpreted. The pseudo-first order and pseudo-second order models were applied to describe the kinetic data. The pseudo-second order kinetic model had excellent kinetic data fitting (R2=1).

  14. Removal of uranium ions from synthetic wastewater using ZnO/Na-clinoptilolite nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Aghadavoud, Azadeh; Saraee, Khadijeh Rezaee Ebrahim; Shakur, Hamid Reza [Isfahan Univ. (Iran, Islamic Republic of). Dept. of Nuclear Engineering; Sayyari, Rasol

    2016-07-01

    Uranium is one of the heavy metals that is found in industrial wastewater and is very toxic for human and environment. In this work, natural clinoptilolite is used as a low-cost adsorbent for uranium removal from aqueous solutions. The sodium form of clinoptilolite and ZnO/Na-clinoptilolite nanocomposite were prepared. The sample sorption capacities for uranium removal from simulated drinking water in the presence of other anions and cations were investigated. Natural zeolite and its modified forms were characterized by XRD, XRF, FTIR, TEM and BET. Batch experiments were used to determine the best adsorption conditions. The effects of various parameters such as contact time, pH, initial uranium concentration, temperature and mass sorbent on the removal efficiency of uranium ions were studied. The equilibration was attained after 2 and 6 h for the Na-clinoptilolite and ZnO/Na-clinoptilolite nanocomposite, respectively. Both adsorbents showed relatively fast adsorption. Effective removal of uranium was demonstrated at pH values of 4-8 for both forms of zeolite. Temperature had no significant effect on adsorption. The maximum removal efficiency of uranium by the ZnO/Na-clinoptilolite nanocomposite in pH=7.2 and room temperature was 98.55%. Langmuir, Freundlich and Sips models were used for describing the equilibrium isotherms for uranium uptake. The Sips model corresponded well with the experimental data. The thermodynamic parameters, such as ΔG , ΔH and ΔS , have been calculated and interpreted. The pseudo-first order and pseudo-second order models were applied to describe the kinetic data. The pseudo-second order kinetic model had excellent kinetic data fitting (R2=1).

  15. 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.

  16. Photodynamic dye adsorption and release performance of natural zeolite

    Science.gov (United States)

    Hovhannisyan, Vladimir; Dong, Chen-Yuan; Chen, Shean-Jen

    2017-03-01

    Clinoptilolite type of zeolite (CZ) is a promising material for biomedicine and pharmaceutics due to its non-toxicity, thermal stability, expanded surface area, and exceptional ability to adsorb various atoms and organic molecules into micropores. Using multiphoton microscopy, we demonstrated that individual CZ particles produce two-photon excited luminescence and second harmonic generation signal at femtosecond laser excitation, and adsorb photo-dynamically active dyes such as hypericin and methylene blue. Furthermore, the release of hypericin from CZ pores in the presence of biomolecules is shown, and CZ can be considered as an effective material for drug delivery and controlled release in biological systems. The results may open new perspectives in application of CZ in biomedical imaging, and introducing of the optical approaches into the clinical environment.

  17. 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.

  18. 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.

  19. Smectite-zeolite envelope surrounding the Tsukiyoshi uranium deposit, central Japan. A natural analogue study

    International Nuclear Information System (INIS)

    Utada, Minoru

    2003-01-01

    The Tsukiyoshi uranium deposit in Gifu Prefecture is the largest one in Japan. It is embedded in lower part of the Mizunami Group of Miocene age. Relating to the existence of this uranium deposit, the constituent minerals in sediments were studied by XRD and SEM, using many drilling cores. The most abundant authigenic mineral is smectite. The amount of smectite increases generally from upper to lower horizons, and a highly smectitized zone is situated around the uranium deposit. Smectitization predominated in mafic glassy grains of sediments, which was probably formed in early burial diagenesis. Zeolites including clinoptilolite-heulandite, mordenite, analcime, chabazite and philipsite are secondly abundant authigenic minerals. They seem to have been formed at early to late diagenetic stages. Opaline silica is rather rare. Carbonate minerals, including calcite, dolomite, siderite and rhodocrosite are common. They may be formed by diagenesis as well. Gypsum and pyrite occur in upper horizons and lower horizons, respectively. In particular, a highly smectitized zone including pyrite probably played an important role for retarding the migration of uranium and as a result keeping the uranium deposit for past one million years. This smectite-zeolite envelope surrounding the Tsukiyoshi uranium deposit is regarded as a natural analogue of the buffer materials surrounding the high-level radioactive waste repository. (author)

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

    Science.gov (United States)

    Farjoo, Afrooz; Kuznicki, Steve M; Sadrzadeh, Mohtada

    2017-10-06

    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.

  1. 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.

  2. Determination of water content in natural zeolites by reflection method

    International Nuclear Information System (INIS)

    Sarria, Lopez P.; Desdin Garcia, V.; Freixas Lemus, V.; Dominguez Ley, O.; Csikai, G.

    1989-01-01

    Water content in natural zeolites collected from different site places in Cuba has been determined by neutron reflection method. Results show that it is possible to separate the minerals abundant in zeolite from the surrounding barren rocks. Water content of about 10% can be determined with 2-3% relative accuracy for different matrices, using 10 m measuring time

  3. 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

  4. 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)

  5. 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

  6. 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

  7. 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.

  8. 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

  9. 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

  10. Preparation of Natural Zeolite for Air Dehumidification in Food Drying

    Directory of Open Access Journals (Sweden)

    Mohamad Djaeni

    2015-03-01

    Full Text Available Drying with air dehumidification with solid adsorbent improves the quality of food product as well as energy efficiency. The natural zeolite is one of adsorbent having potential to adsorb the water.  Normally, the material was activated to open the pore, remove the organic impurities, and increase Si/Al rate. Hence, it can enhance the adsorbing capacity. This research studied the activation of natural zeolite mined from Klaten, Indonesia as air dehumidification for food drying. Two different methods were used involving activation by heat and NaOH introduction.  As indicators, the porosity and water loaded were evaluated. Results showed both methods improved the adsorbing capacity significantly. With NaOH, the adsorbing capacity was higher. The simple test in onion and corn drying showed the presence of activated natural zeolite can speed up water evaporation positively. This performance was also comparable with Zeolite 3A

  11. 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

  12. Ozone decomposition on Ag/SiO{sub 2} and Ag/clinoptilolite catalysts at ambient temperature

    Energy Technology Data Exchange (ETDEWEB)

    Nikolov, Penko, E-mail: penmail@mail.bg [Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Genov, Krassimir; Konova, Petya [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Milenova, Katya; Batakliev, Todor; Georgiev, Vladimir [Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Kumar, Narendra [Laboratory of Industrial Chemistry, Process Chemistry Centre, Abo Akademi University, Biskopsgatan 8, 20500 Abo/Turku (Finland); Sarker, Dipak K. [School of Pharmacy and Biomolecular Sciences, University of Brighton, Lewes Road, Brighton BN2 4GJ (United Kingdom); Pishev, Dimitar [University of Chemical Technology and Metallurgy, 1756 Sofia (Bulgaria); Rakovsky, Slavcho [Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)

    2010-12-15

    Silver modified zeolite (Bulgarian natural clinoptilolite) and Ag/silica catalysts were synthesized by ion exchange and incipient wet impregnation method respectively and characterized by different techniques. DC arc-AES was used for Ag detection. XRD spectra show that Ag is loaded over the surface of the SiO{sub 2} sample and that after the ion-exchange process the HEU type structure of clinoptilolite is retained. UV-VIS (specific reflection at 310 nm) and IR (band at 695 cm{sup -1}) spectroscopy analysis proved that silver is loaded as a T-atom into zeolite channels as Ag{sup +}, instead of Na{sup +}, Ca{sup 2+}, or K{sup +} ions, existing in the natural clinoptilolite form. The samples Ag/SiO{sub 2} and Ag-clinoptilolite were tested as catalysts for decomposition of gas phase ozone. Very high catalytic activity (up to 99%) was observed and at the same time the catalysts remained active over time at room temperature.

  13. Biogas cleaning and upgrading with natural zeolites from tuffs.

    Science.gov (United States)

    Paolini, Valerio; Petracchini, Francesco; Guerriero, Ettore; Bencini, Alessandro; Drigo, Serena

    2016-01-01

    CO2 adsorption on synthetic zeolites has become a consolidated approach for biogas upgrading to biomethane. As an alternative to synthetic zeolites, tuff waste from building industry was investigated in this study: indeed, this material is available at a low price and contains a high fraction of natural zeolites. A selective adsorption of CO2 and H2S towards CH4 was confirmed, allowing to obtain a high-purity biomethane (CO2 biogas samples were used, and no significant effects due to biogas impurities (e.g. humidity, dust, moisture, etc.) were observed. Thermal and vacuum regenerations were also optimized and confirmed to be possible, without significant variations in efficiency. Hence, natural zeolites from tuffs may successfully be used in a pressure/vacuum swing adsorption process.

  14. 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.

  15. 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)

  16. 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)

  17. Characterization of Mongolian Natural Minerals and Their Application for Heavy Metal Adsorbent

    OpenAIRE

    Dolgormaa, Munkhbat; Shiomori, Koichiro; Bayanjargal, Ochirkhuyag

    2016-01-01

    In this study, the structural characteristic and the adsorption properties of heavy metals on Mongolian natural minerals were investigated. The natural samples were confirmed as Heulandite group of Clinoptilolite type zeolite and clay sample that contains albite and quartz by X-ray diffraction analysis. According to BET surface analysis, natural zeolites have mesoporous type of pore. The results of adsorption study showed that adsorption ability of natural zeolite is high effective for lead i...

  18. ZEOLITE: "THE MAGIC STONE"; MAIN NUTRITIONAL, ENVIRONMENTAL, EXPERIMENTAL AND CLINICAL FIELDS OF APPLICATION.

    Science.gov (United States)

    Laurino, Carmen; Palmieri, Beniamino

    2015-08-01

    zeolites (clinoptilolites) are a family of alluminosilicates and cations clustered to form macro aggregates by small individual cavities. In the medical area they are involved in detoxification mechanisms capturing ions and molecules into their holes. Actually, we classify about 140 types of natural and 150 synthetic zeolites, for specific and selective use. Clinoptilolite is a natural zeolite and it is the most widespread compound in the medical market. this review analyzes the main fields of zeolite utilization. we searched Pubmed/Medline using the terms "zeolite" and "clinoptilolite". in zoothechnology and veterinary medicine zeolite improves the pets' fitness, removes radioactive elements, aflatoxines and poisons. Zeolite displays also antioxidant, whitening, hemostatic and anti-diarrhoic properties, projected in human care. However very scanty clinical studies have been run up to now in immunodeficiency, oncology after chemotherapy and radiotherapy as adjuvants. further clinical investigations are urgently required after this review article publication which updates the state of the art. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  19. Reduction volume of radioactive wastes using natural zeolite

    International Nuclear Information System (INIS)

    Endro Kismolo; Nurimaniwathy; Vemi Ridantami

    2013-01-01

    The aim of this experience was to know of the characteristics of zeolite as the sorbent for reduction volume of liquid waste with the Pb contaminant contain. The experiment was done by sorption method a batch performed by using zeolite from Gedangsari Gunung Kidul with the grain size (-60+80) mesh, (-80+100) mesh dan (-100+120) mesh which was activated by (NH 4 ) CI and NH 4 N0 3 1.0 M. Weight of sorbent was added was variated from 5.0 to 40.0 %, and variation of silica sand to added from 0.5 to 2.5 % of weight sorbent. Stirring speed was varied from 30 to 180 rpm and the stirring time of 10 to 120 minutes, and filtrates from filtering process to analyzed by Absorption Analysis Spectrophotometry utilities. From the experience can be achieved of data that the best sorption to obtained at the condition of zeolite on (-80+100) mesh, sorbent added of 25 %, stirring speed of 120 rpm, time of stirring of 90 minutes, and the setting time of 120 minutes. At this condition to obtained sorption efficiency are 64.162 % for natural zeolite, 7.034 % for zeolite be activated with NH 4 N0 3 and 77.414 % for zeolite be activated with NH 4 Cl 1.0 M. (author)

  20. Intracrystalline diffusion in clinoptilolite: Implications for radionuclide isolation

    International Nuclear Information System (INIS)

    Roberts, S.K.; Viani, B.E.; Phinney, D.

    1995-01-01

    Experiments have been performed to measure the rate of exchange diffusion in the zeolite clinoptilolite (CL) for elements important to radionuclide isolation at Yucca Mountain, NV. Clinoptilolite is one of the major sorptive minerals in the tuffs at Yucca Mountain, and occurs both as a major component in zeolitized units (Calico Hills), and in fractures in non-zeolitized tuffs (Topopah Spring). Field evidence and numerical modeling suggests that the movement of fluids through the tuff rocks adjacent to the potential repository may occur via episodic flow through fractures. Under conditions of rapid fracture flow the effective sorptive capacity of fracture-lining clinoptilolite may be controlled by exchange diffusion rather than exchange equilibrium

  1. Ion exchangers in radioactive waste management: natural Iranian zeolites.

    Science.gov (United States)

    Nilchi, A; Maalek, B; Khanchi, A; Ghanadi Maragheh, M; Bagheri, A; Savoji, K

    2006-01-01

    Five samples of natural zeolites from different parts of Iran were chosen for this study. In order to characterize and determine their structures, X-ray diffraction and infrared spectrometry were carried out for each sample. The selective absorption properties of each zeolite were found by calculating the distribution coefficient (K(d)) of various simulated wastes which were prepared by spiking the radionuclides with (131)I, (99)Mo, (153)Sm, (140)La and (147)Nd. All the zeolite samples used in this study had extremely high absorption value towards (140)La; clinoptolite from Mianeh and analsite from Ghalehkhargoshi showed good absorption for (147)Nd; clinoptolite from Semnan and clinoptolite from Firozkoh showed high absorption for (153)Sm; mesolite from Arababad Tabas showed good absorption for (99)Mo; and finally mesolite from Arababad Tabas, clinoptolite from Semnan and clinoptolite from Firozkoh could be used to selectively absorb (131)I from the stimulated waste which was prepared. The natural zeolites chosen for these studies show a similar pattern to those synthetic ion exchangers in the literature and in some cases an extremely high selectivity towards certain radioactive elements. Hence the binary separation of radioactive elements could easily be carried out. Furthermore, these zeolites, which are naturally occurring ion exchangers, are viable economically and extremely useful alternatives in this industry.

  2. A short review of the formation, stability, and cementing properties of natural zeolites

    International Nuclear Information System (INIS)

    Jacobsson, A.

    1977-10-01

    The buffer mass for embedding nuclear waste canisters way down in tunnels or bore holes must fulfil a number of requirements. A 10-15 percent (by weight) sodium bentonite and 85-90 percent quartz mass has been suggested. In most respects this buffer mass has excellent properties but its ion exchange capacity is moderate or low. For this reason zeolites have been suggested as an active component in the mass. The question has been, however, whether zeolites are chemically stable together with other minerals such as montmorillonite which still has to be used to give the buffer mass suitable plastic and permeable properties. It is the main object of this report to illustrate any behaviour of zeolites relevant to the problem of finding a suitable buffer mass. Analcime or analcite, phillipsite, chabazite and clinoptilolite have been suggested as possible components in our buffer mass. (author)

  3. A study on ammonia removal properties using clinoptilolite Part 1 : characterization of clinoptilolite and ammonia removal properties in batch reactor

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Jeong Min; Chung, Jong Shik [Dept. of Chemical Engineering/School of Environment Engineering, Pohang University of Science and Technology, Pohang (Korea); Sun, De Shi [Dept. of Applied Chemistry, Harbin Institute of Techonology (China)

    2000-04-01

    A natural zeolite, deposit located at Guryongpo, Young-il bay, was found to be clinoptilolite containing impurities of heulandite and mordenite. Cation exchange capacity(CEC) for ammonia was about 1.41 meq/g from Na{sup +}-form of the zeolite. In batch experiment, removal efficiency of ammonia was increased as particle size of zeolite and initial concentration of Na{sup +} were decreased and SR(Stoichiometric Ratio), time, and initial concentration of ammonia increased. More than 70% aluminum ion could be removed from water having 3 ppm ammonia and 0.7 ppm Al{sup 3+} by the batch adsorption(ion exchange) experiment. Regeneration of used zeolite with NaCl solution of pH=12 has shown more than 95% of regeneration efficiency when SR'(ratio of the amount of NaCl solution employed actually to the amount in a stoichiometric quantity) was equal to 2.0. 19 refs., 10 figs., 1 tab.

  4. Efficient removal of cesium from low-level radioactive liquid waste using natural and impregnated zeolite minerals.

    Science.gov (United States)

    Borai, E H; Harjula, R; Malinen, Leena; Paajanen, Airi

    2009-12-15

    The objective of the proposed work was focused to provide promising solid-phase materials that combine relatively inexpensive and high removal capacity of some radionuclides from low-level radioactive liquid waste (LLRLW). Four various zeolite minerals including natural clinoptilolite (NaNCl), natural chabazite (NaNCh), natural mordenite (NaNM) and synthetic mordenite (NaSM) were investigated. The effective key parameters on the sorption behavior of cesium (Cs-134) were investigated using batch equilibrium technique with respect to the waste solution pH, contacting time, potassium ion concentration, waste solution volume/sorbent weight ratio and Cs ion concentration. The obtained results revealed that natural chabazite (NaNCh) has the higher distribution coefficients and capacity towards Cs ion rather than the other investigated zeolite materials. Furthermore, novel impregnated zeolite material (ISM) was prepared by loading Calix [4] arene bis(-2,3 naphtho-crown-6) onto synthetic mordenite to combine the high removal uptake of the mordenite with the high selectivity of Calix [4] arene towards Cs radionuclide. Comparing the obtained results for both NaSM and the impregnated synthetic mordenite (ISM-25), it could be observed that the impregnation process leads to high improvement in the distribution coefficients of Cs+ ion (from 0.52 to 27.63 L/g). The final objective in all cases was aimed at determining feasible and economically reliable solution to the management of LLRLW specifically for the problems related to the low decontamination factor and the effective recovery of monovalent cesium ion.

  5. Efficient removal of cesium from low-level radioactive liquid waste using natural and impregnated zeolite minerals

    International Nuclear Information System (INIS)

    Borai, E.H.; Harjula, R.; Malinen, Leena; Paajanen, Airi

    2009-01-01

    The objective of the proposed work was focused to provide promising solid-phase materials that combine relatively inexpensive and high removal capacity of some radionuclides from low-level radioactive liquid waste (LLRLW). Four various zeolite minerals including natural clinoptilolite (NaNCl), natural chabazite (NaNCh), natural mordenite (NaNM) and synthetic mordenite (NaSM) were investigated. The effective key parameters on the sorption behavior of cesium (Cs-134) were investigated using batch equilibrium technique with respect to the waste solution pH, contacting time, potassium ion concentration, waste solution volume/sorbent weight ratio and Cs ion concentration. The obtained results revealed that natural chabazite (NaNCh) has the higher distribution coefficients and capacity towards Cs ion rather than the other investigated zeolite materials. Furthermore, novel impregnated zeolite material (ISM) was prepared by loading Calix [4] arene bis(-2,3 naphtho-crown-6) onto synthetic mordenite to combine the high removal uptake of the mordenite with the high selectivity of Calix [4] arene towards Cs radionuclide. Comparing the obtained results for both NaSM and the impregnated synthetic mordenite (ISM-25), it could be observed that the impregnation process leads to high improvement in the distribution coefficients of Cs + ion (from 0.52 to 27.63 L/g). The final objective in all cases was aimed at determining feasible and economically reliable solution to the management of LLRLW specifically for the problems related to the low decontamination factor and the effective recovery of monovalent cesium ion.

  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. 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...

  8. 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

  9. Effect of alkali-treatment on the characteristics of natural zeolites with different compositions.

    Science.gov (United States)

    Ates, Ayten

    2018-08-01

    A series of natural zeolites with different compositions were modified by post-synthesis modification with sodium hydroxide (NaOH) solution. Natural and modified zeolites were characterized by XRD, SEM, nitrogen adsorption, FTIR, zeta potential and temperature programmed desorption of ammonia (NH 3 -TPD). The adsorption capacities of these samples were evaluated by the adsorption of manganese from aqueous solution. The treatment with NaOH led to a decrease in the surface area and microporosity of all natural zeolites as well as partly damage of the zeolite structure depending on zeolite composition. In addition, the amount of weak, medium and strong acid sites in the zeolites was changed significantly by NaOH treatment depending on zeolite composition. The NaOH treatment resulted in a four-fold improvement in adsorption capacity of natural zeolite originated from Bigadic and a twofold decrease in that of the natural zeolite originated from Manisa-Gordes. Although the improved adsorption capacity might be mainly due to modification of porosity in the zeolites and formation of hydroxysodalite, the reduced adsorption capacity of the zeolite might be mainly due to a significant deformation of the zeolite structure. The pseudo-second-order kinetic model for the adsorption of manganese on all natural and modified zeolites fits well. Copyright © 2018 Elsevier Inc. All rights reserved.

  10. 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.

  11. Biogas Filter Based on Local Natural Zeolite Materials

    OpenAIRE

    Krido Wahono, Satriyo; Anggo Rizal, Wahyu

    2014-01-01

    UPT BPPTK LIPI has created a biogas filter tool to improve the purity of methane in the biogas. The device shaped cylindrical tube containing absorbent materials which based on local natural zeolite of Indonesia. The absorbent has been activated and modified with other materials. This absorbtion material has multi-adsorption capacity for almost impurities gas of biogas. The biogas  filter increase methane content of biogas for 5-20%. The biogas filter improve the biogas’s performance such as ...

  12. Use of natural zeolites for creation of catalysts containing Cu, Cr, Co, Fe for total oxidation of CO, CH4, CH3OH gas wastes

    International Nuclear Information System (INIS)

    Grigoryan, R.R.; Vartikyan, L.A.; Gharibyan, T.A.; Sargsyan, H.H.

    2006-01-01

    On the basis of natural zeolites of 'Nor Koghb' from Noyemberyan Region of Armenia various quantities of metal containing (Cu,Cr, Co, Fe) catalysts were synthesized by methods of: impregnation; impregnation by ultrasonic treatment (UST); ion exchange. It was studied physico-chemical properties of synthesized catalysts with the help of X-ray, ESR and electronic microscope. Catalytic activity of synthesized catalysts is studied in the processes of deep oxidation by air under atmospheric pressure of methanol, carbon oxide and methane. It is shown that increase of quantity of CuO>2 weight % in clinoptilolite leads to decrease of CO, CH 3 OH and CH 4 conversion and increase of quantity of CoO, Cr 2 O 3 , Fe 2 O 3 (2-6 weight %) leads to increase of above mentioned conversion.These catalysts preserve their catalytic activity for a long period of time

  13. Calcining natural zeolites to improve their effect on cementitious mixture workability

    International Nuclear Information System (INIS)

    Seraj, Saamiya; Ferron, Raissa D.; Juenger, Maria C.G.

    2016-01-01

    Despite the benefits to long-term concrete durability, the use of natural zeolites as supplementary cementitious materials (SCMs) is uncommon due to their high water demand. The motivation of the research presented here was to better understand how the physical and chemical characteristics of natural zeolites influenced the workability of cementitious mixtures and whether those properties could be modified through calcination to mitigate the high water demand of natural zeolites. In this research, three different natural zeolites were characterized in their original and calcined states using x-ray diffraction (XRD) and Brunauer–Emmett–Teller (BET) surface area measurements. Rheology experiments were then conducted on cementitious pastes containing these natural zeolites, in their original and calcined states, to assess mixture viscosity and yield stress. Results showed that calcination destabilized the structure of the natural zeolites and reduced their surface area, which led to an improvement in mixture viscosity and yield stress.

  14. 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

  15. 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

  16. Utilization of Natural Zeolite from Ponorogo and Purworejo for Naphthol Substance Adsorption

    Science.gov (United States)

    Imandiani, Sundus; Indira, Christine; Johan, Anthony; Budiyono

    2018-02-01

    Indonesia has many zeolite producing areas yet untapped. Researchers developed the utilization of natural zeolites useful for the adsorption of naphthol dyes commonly found in batik waste. In this study researchers used natural zeolites from Purworejo and Ponorogo that are activated using hydrochloric acid that is used for adsorption. The purpose of this research is to know the effect of natural zeolite activation from Ponorogo and Purworejo on the effectiveness of adsorption of naphthol dyes widely used in batik industry. Natural zeolite was activated using HCl concentration of 1.3N; 1.8N; 3.2N; and 3.9N for 60 minutes. The methods are preparation of natural zeolite from Purworejo and Ponorogo, dealumination using hydrochloric acid, adsorption process of naphthol dyes using activated zeolite, and test of adsorption result with uv-vis spectrophotometry. The test results showed that the higher HCl concentration will increase adsorption capacity. This can be known from the concentration of naphthol dye which decreased both using natural zeolite Ponorogo and Purworejo. While the effectiveness of adsorption shows natural zeolite Purworejo has a greater adsorption capacity than Ponorogo with optimum conditions of dealumination using concentration HCl 3,9N.

  17. 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.

  18. Biogas Filter Based on Local Natural Zeolite Materials

    Directory of Open Access Journals (Sweden)

    Satriyo Krido Wahono

    2014-02-01

    Full Text Available UPT BPPTK LIPI has created a biogas filter tool to improve the purity of methane in the biogas. The device shaped cylindrical tube containing absorbent materials which based on local natural zeolite of Indonesia. The absorbent has been activated and modified with other materials. This absorbtion material has multi-adsorption capacity for almost impurities gas of biogas. The biogas  filter increase methane content of biogas for 5-20%. The biogas filter improve the biogas’s performance such as increasing methane contents, increasing heating value, reduction of odors, reduction of corrosion potential, increasing the efficiency and stability of the generator.

  19. 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

  20. 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

  1. 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

  2. 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

  3. Effect of cation nature of zeolite on carbon replicas and their electrochemical capacitance

    International Nuclear Information System (INIS)

    Zhou, Jin; Li, Wen; Zhang, Zhongshen; Wu, Xiaozhong; Xing, Wei; Zhuo, Shuping

    2013-01-01

    Graphical abstract: Cation nature of zeolite influences the porosity, surface chemical properties of carbon replicas of zeolite, resulting in different electrochemical capacitance. Highlights: ► The porosity of carbon replica strongly depends on zeolite's effective pore size. ► The surface chemical properties influence by the cation nature of zeolite. ► The N-doping introduces large pseudo-capacitance. ► The HYC800 carbon showed a high capacitance of up to 312 F g −1 in 1 M H 2 SO 4 . ► The prepared carbons show good durability of galvanostatic cycle. -- Abstract: N-doped carbon replicas of zeolite Y are prepared, and the effect of cation nature of zeolite (H + or Na + ) on the carbon replicas is studied. The morphology, structure and surface properties of the carbon materials are investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), N 2 adsorption, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR). The pore regularity, pore parameter and surface chemical properties of the carbons may strongly depend on the cation nature of the zeolite Y. The carbon replicas of zeolite HY (H-form of zeolite Y) possesses higher pore regularity and much larger surface area than those of zeolite NaY (Na-form of zeolite Y), while the latter carbons seem to possess higher carbonization degrees. Electrochemical measurements show a large faradaic capacitance related to the N- or O-containing groups for the prepared carbons. Owing to the large specific surface area, high pore regularity and heteroatom-doping, the HYC800 sample derived from zeolite HY presents very high gravimetric capacitance, up to 312.4 F g −1 in H 2 SO 4 electrolyte, and this carbon can operate at 1.2 V with good retention ratio in the range of 0.25 to 10 A g −1

  4. Removal and recovery of p-phenylenediamines developing compounds from photofinishing lab-washwater using clinoptilolite tuffs from Greece.

    Science.gov (United States)

    Vlessidis, A G; Triantafillidis, C S; Evmiridis, N P

    2001-04-01

    Clinoptilolite tuffs from areas in Thrace region of Greece are compared with synthetic zeolites NaY and NH4Y for the uptake of N4-ethyl-N4-(2-methansulphonamidoethyl)-2-methyl-1,4-phenylenediamin (sesquisulphate, monohydrate) with the trade name CD-3 for the purpose to be used for clean-up and recycling photo-finishing and photo-developing washwaters. The cation-exchange capacity is found to be 6.15-11.1 mg/g for zeoliferous tuffs at equilibrium concentration of 50 ppm CD-3 in aqueous solution compared to 65.0 mg/g of NaY and 48.2 mg/g for NH4Y synthetic zeolites corresponding to the removal of CD-3 from 120 to 2001 of 50 ppm aqueous solution per kg of natural zeoliferous tuff; this capacity is only 6-10 times lower than type-Y synthetic zeolite. Initial rates of uptake are 20.8 mg/l/min for natural and 38.5 mg/l/min for synthetic zeolites. Regeneration levels of 55, 23, 35, and 33% are obtained for MCH, SF, NaY, and NH4Y, respectively. The rapid and almost complete uptake of CD-3 from its aqueous solutions at low CD-3 concentrations by the natural zeolites is promising for such an application.

  5. 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.

  6. 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.

  7. Multi-elemental characterization of Cuban natural zeolites

    International Nuclear Information System (INIS)

    Rizo, O.D.; Peraza, E.F.H.

    1997-01-01

    Concentration of 38 elements in samples from four important Cuban zeolite beds have been obtained by Instrumental Neutron Activation (INAA) and X-ray Fluorescence analyses (XRFA). In comparison with other analytical techniques good agreement was reached. 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. (author)

  8. 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

  9. Modification of Natural Zeolite with Fe(III) and Its Application as Adsorbent Chloride and Carbonate ions

    Science.gov (United States)

    Suhartana; Sukmasari, Emmanuella; Azmiyawati, Choiril

    2018-04-01

    The aim of the research is to natural zeolite with Fe(III) using anion exchange process to improve the anion exchange capacity. Natural zeolite was activated using HNO3 1 N and then mixed with FeCl3 solution and refluxed followed by oven and calcination at a temperature of 550°C. The influence of Fe(III) to zeolite was characterized by FTIR while presence of Fe in zeolite characterized by AAS. Zeolite and Zeolite-Fe adsorption capacity of chloride and carbonate anions were determined through adsorption test by variation of pH and contact time. In advanced, and then to determining the Fe adsorbed concentration at Zeolite using UV-Vis spectrophotometer. FTIR analysis result showed that the addition of Fe does not affect the zeolite’s structure but change the intensity of the zeolite spectra. The Fe concentration in Zeolite-Fe of 714 mg L-1, indicate that Fe was present in the zeolite. Both Zeolite and Zeolite-Fe adsorbtion results showed that optimum pH of Chloride anion is 2, with adsorption capacity 2,33 x 10-3 gg-1 and optimum contact time is 8 minutes. While Zeolite and Zeolite-Fe adsorbtion results showed that optimum pH of Carbonate anion is 5, with adsorption capacity 5,31 x 10-3 gg-1 and optimum contact time is 8 minutes.

  10. Synthesis and characterization of mesoporous NaY zeolite from natural Blitar’s kaolin

    Science.gov (United States)

    Khalifah, S. N.; aini, Z. N.; Hayati, E. K.; Aini, N.; Prasetyo, A.

    2018-03-01

    Mesoporous NaY Zeolite has been synthesized from calcined natural Blitar’s kaolin with the addition of NaOH and CTABr surfactant as mesoporous template by hydrothermal method. Natural kaolin was calcinated with different time and temperature to change kaolin to metakaolin. X-ray diffraction data showed that mesoporous NaY zeolite was formed with impurities compound of sodalite, kaolin and quartz phases. The BET analysis resulted that the pore of NaY Zeolite belongs to mesoporous type with pore size 9,421 nm. Characterization from FTIR confirmed about the functional group of zeolites (988, 776, 663, 464 cm-1). Scanning electron microscopy characterization showed that the morphological of mesoporous NaY zeolites have uniform and crystalline particles formed.

  11. Effect of Zeolite Treatment on the Blooming Behavior of Paraffin Wax in Natural Rubber Composites

    Directory of Open Access Journals (Sweden)

    Bryan B. Pajarito

    2016-06-01

    Full Text Available The blooming behavior of paraffin wax in natural rubber (NR composites was studied as function of zeolite treatment. Three types of zeolite treatment were treated as factors: acid activation using hydrochloric acid (HCl solution, ion exchange using tetradecyldimethyl amine (TDA chloride salt, and organic modification using glycerol monostearate (GMS. The zeolite was treated according to a 23 full factorial design of experiment. Attenuated total reflectance – Fourier transform infrared (ATR-FTIR spectroscopy was used to characterize the chemical structure of treated zeolite. Treated zeolite was applied as filler to NR composites deliberately compounded with high amount of paraff in wax. The amount of bloomed wax in surface of NR composite sheets was monitored with time at 50oC. Results show the bloom amount to be linear with the square root of time. NR composites reinforced with untreated, acid-activated, and ion-exchanged zeolite fillers indicate reduction in wax blooming as compared to unfilled NR. The bloom rate (slope and initial bloom (y-intercept were determined from the experimental plots. Analysis of variance (ANOVA shows the bloom rate to be signif icantly increased when zeolite fillers are treated with GMS. Meanwhile, initial bloom was significantly enhanced when zeolite fillers are treated with TDA chloride salt and GMS. The significant increase in bloom rate and initial bloom can be attributed to the softening of the NR matrix at high amounts of TDA chloride salt and GMS.

  12. Removal of Cu(II) from leachate using natural zeolite as a landfill liner material

    International Nuclear Information System (INIS)

    Turan, N. Gamze; Ergun, Osman Nuri

    2009-01-01

    All hazardous waste disposal facilities require composite liner systems to act as a barrier against migration of contaminated leachate into the subsurface environment. Removal of copper(II) from leachate was studied using natural zeolite. A serial of laboratory systems on bentonite added natural zeolite was conducted and copper flotation waste was used as hazardous waste. The adsorption capacities and sorption efficiencies were determined. The sorption efficiencies increased with increasing natural zeolite ratio. The pseudo-first-order, the pseudo-second-order, Elovich and the intra-particle diffusion kinetic models were used to describe the kinetic data to estimate the rate constants. The second-order model best described adsorption kinetic data. The results indicated that natural zeolite showed excellent adsorptive characteristics for the removal of copper(II) from leachate and could be used as very good liner materials due to its high uptake capacity and the abundance in availability.

  13. Removal of Cu(II) from leachate using natural zeolite as a landfill liner material.

    Science.gov (United States)

    Turan, N Gamze; Ergun, Osman Nuri

    2009-08-15

    All hazardous waste disposal facilities require composite liner systems to act as a barrier against migration of contaminated leachate into the subsurface environment. Removal of copper(II) from leachate was studied using natural zeolite. A serial of laboratory systems on bentonite added natural zeolite was conducted and copper flotation waste was used as hazardous waste. The adsorption capacities and sorption efficiencies were determined. The sorption efficiencies increased with increasing natural zeolite ratio. The pseudo-first-order, the pseudo-second-order, Elovich and the intra-particle diffusion kinetic models were used to describe the kinetic data to estimate the rate constants. The second-order model best described adsorption kinetic data. The results indicated that natural zeolite showed excellent adsorptive characteristics for the removal of copper(II) from leachate and could be used as very good liner materials due to its high uptake capacity and the abundance in availability.

  14. Recovery of Nutrients from Biogas Digestate with Biochar and Clinoptilolite

    DEFF Research Database (Denmark)

    Kocatürk, Nazli Pelin

    in recovery of nutrients whose natural reserves are being depleted such as phosphorus and potassium. In this thesis I propose the use of sorbents i.e. biochar and clinoptilolite to concentrate nutrients and subsequently the application of digestate-enriched biochar and clinoptilolite as fertiliser. Therefore...... the overall objective of this thesis is to investigate the use of clinoptilolite and biochar to recover plant nutrients from the liquid fraction of digestate resulting from anaerobic digestion of animal manure and investigate the plant-availability of the recovered form of nutrients. In Chapter 1 (General...... of nutrients on sorbent) but decreasing efficiencies of clinoptilolite to remove nutrients from the liquid fraction of digestate. In Chapter 3, I studied the chemical activation of biochar by treating the biochar with deionised water, hydrogen peroxide, sulfuric acid and sodium hydroxide solutions...

  15. Influence of natural zeolite and nitrification inhibitor on organics degradation and nitrogen transformation during sludge composting.

    Science.gov (United States)

    Zhang, Junya; Sui, Qianwen; Li, Kun; Chen, Meixue; Tong, Juan; Qi, Lu; Wei, Yuansong

    2016-01-01

    Sludge composting is one of the most widely used treatments for sewage sludge resource utilization. Natural zeolite and nitrification inhibitor (NI) are widely used during composting and land application for nitrogen conservation, respectively. Three composting reactors (A--the control, B--natural zeolite addition, and C--3,4-dimethylpyrazole phosphate (DMPP) addition) were established to investigate the influence of NI and natural zeolite addition on organics degradation and nitrogen transformation during sludge composting conducted at the lab scale. The results showed that, in comparison with the control, natural zeolite addition accelerated organics degradation and the maturity of sludge compost was higher, while the DMPP addition slowed down the degradation of organic matters. Meanwhile, the nitrogen transformation functional genes including those responses for nitrification (amoA and nxrA) and denitrification (narG, nirS, nirK, and nosZ) were quantified through quantitative PCR (qPCR) to investigate the effects of natural zeolites and DMPP addition on nitrogen transformation. Although no significant difference in the abundance of nitrogen transformation functional genes was observed between treatments, addition of both natural zeolite and DMPP increases the final total nitrogen content by 48.6% and 23.1%, respectively. The ability of natural zeolite for nitrogen conservation was due to the absorption of NH3 by compost, and nitrogen conservation by DMPP was achieved by the source reduction of denitrification. Besides, it was assumed that the addition of natural zeolite and DMPP may affect the activity of these genes instead of the abundance.

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

    OpenAIRE

    F. Golbabaei; E. Rahmanzadeh; G. R. Moussavi; A. Faghihi zarandi; M. R. Baneshi

    2014-01-01

    Introduction: Chromium (VI) is a known human carcinogenic agent which is used in numerous industrial processes such as electroplating, welding, textile, cement and steel fabrication. The aim of this study was to determine the effectiveness of natural zeolite on the fixed bed adsorption of Cr (VI) from air stream. . Material and Method: In this experimental study, chromium mists were generated by a nebulizer (3A model, Italy). Performance of natural zeolite in the Cr (VI) adsorption and ...

  17. 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.

  18. 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.

  19. 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

  20. Characterization of sonicated natural zeolite/ferric chloride hexahydrate by infrared spectroscopy

    Science.gov (United States)

    Prasetyo, T. A. B.; Soegijono, B.

    2018-03-01

    The characteristics of sonicated Bayah natural zeolite with and without ferric chloride hexahydrate solution using infrared method has been studied. High intensity ultrasonic waves were exposed to the samples for 40 min, 80 min and 120 min. Infra red spectra analysis was conducted to evaluate zeolite vibrational spectrum contributions, namely, the vibrations from the framework of the zeolite, from the charge-balancing cations, and from the relatively isolated groups, such as the surface OH groups and their behavior after sonication process. An addition of FeCl3.6H2O and sonication process on natural zeolite improved secondary building units link by forming oxygen bridges and also close relationship with duration of applied high intensity ultrasonic process. Longer ultrasonic process resulted in more increment of O-H absorbance.

  1. 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.

  2. 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

  3. Characterization and Activation of Indonesian Natural Zeolite from Southwest Aceh District-Aceh Province

    Science.gov (United States)

    Yulianis, Y.; Muhammad, S.; Pontas, K.; Mariana, M.; Mahidin, M.

    2018-05-01

    This study aims to identify the effect of activation processes of Indonesian zeolite from Southwest Aceh District, Aceh Province on the physical characteristics and chemical contents changes. The work was conducted by downsizing of natural zeolite into nano particle size, treating it physically (heated up to 105˚C) and chemically (soaked with 0.5 M HCl for 1 hour), and finally calcining it at the temperature of 350° C for 2 hours. The natural and activated nano zeolites were then characterized by using SEM, BET, XRD, XRF and FTIR in order to examine their characters and chemical contents. The characterization results showed that the activated nano zeolite has better appearances than the natural one. The XRD analysis showed that the main minerals of zeolite are quartz and calcite clinochlore. Further, the XRF analysis showed that there are elements of magnesium, calcium and potassium which can be as a cation exchange with other metal elements. Based on the identified properties, this zeolite showed a good performance to be used as an adsorbent in waste water treatment process, especially after activated.

  4. The remediation of the lead-polluted garden soil by natural zeolite.

    Science.gov (United States)

    Li, Hua; Shi, Wei-yu; Shao, Hong-bo; Shao, Ming-an

    2009-09-30

    The current study investigated the remediation effect of lead-polluted garden soil by natural zeolite in terms of soil properties, Pb fraction of sequential extraction in soil and distribution of Pb in different parts of rape. Natural zeolite was added to artificially polluted garden soil to immobilize and limit the uptake of lead by rape through changing soil physical and chemical properties in the pot experiment under greenhouse conditions. Results indicated that the addition of natural zeolite could increase soil pH, CEC, content of soil organic matter and promote formation of soil aggregate. The application of zeolite decreased the available fraction of Pb in the garden soil by adjusting soil pH rather than CEC, and restrained the Pb uptake by rape. Data obtained suggested that the application of a dose of zeolite was adequate (>or=10 g kg(-1)) to reduce soluble lead significantly, even if lead pollution is severe in garden soil (>or=1000 mg kg(-1)). An appropriate dose of zeolite (20 g kg(-1)) could reduce the Pb concentration in the edible part (shoots) of rape up to 30% of Pb in the seriously polluted soil (2000 mg kg(-1)).

  5. Effect of precipitation conditions on the magnetic and sorption properties of zeolite-maghemite composites

    International Nuclear Information System (INIS)

    Matik, M.; Pechousek, J.; Zboril, R.; Sepelak, V.

    2006-01-01

    Natural zeolite (clinoptilolite) from Nizny Hrabovec (Slovakia) has been magnetically modified through maghemite (γ-Fe 2 O 3 ) nanoparticles by precipitation route at various reaction conditions. An effect of the precipitation temperature, weight ratio of Fe/zeolite and interaction time on the magnetic and surface properties of maghemite-zeolite composites was monitored by Moessbauer spectroscopy, TEM and BET surface area measurements. A decrease in reaction time and the Fe/zeolite ratio leads to smaller particles of γ-Fe 2 O 3 while lowering the precipitation temperature results in the larger crystallites. The reflection of the precipitation temperature being the key variable in the sorption properties of composites was tested with selected heavy metal ions. The sample prepared at highest temperature of 85 grad C reveals much higher maximum sorption capacity for Pb 2+ than commonly observed for magnetically modified natural zeolites. Good ability for sorption of anions was demonstrated with AsO 4 3- , which offers new applications of such modified zeolites. The sample with the best sorption properties was characterized by SEM, XRD, in-field Moessbauer spectroscopy and magnetic measurements. Following these data, maghemite nanoparticles form aggregates, which are sorbed on zeolite inhomogeneously with some free active surface of zeolite. The particles are about 15 nm in size and reveal the partial vacancies ordering as documented through the increased ratio of tetrahedral and octahedral positions being of 1/3. FC/ZFC curves confirm strongly interacting superparamagnetic particles with a blocking temperature of 230 K. (authors)

  6. 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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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

  9. Studies of the water adsorption on Lampung’s natural zeolite of Indonesia for cooling application

    Science.gov (United States)

    Wulandari, D. A.; Nasruddin; Lemington

    2018-03-01

    Part of minerals that originally formed from volcanic rock and ash layers reacting further with alkaline groundwater is called natural zeolite, where its sources are not always available in all countries. Indonesia is located in the ring of fire which have a huge sources of zeolite, one of the area is Lampung, South Sumatra. Natural zeolite has been considered as one of potential heat adsorbent medium which can contribute to the energy consumption and reduce air pollution in the using of cooling application. The characteristic of this Lampung natural zeolite such as adsorption kinetics, adsorption water uptake, and adsorption capacity were test with ASAP 2020 system. Sorption kinetics by this experiment of zeolite samples were carried out in a constant temperature and humidity chamber. The chamber can supply constant air condition with deviations of ±0.5 °C for temperature and ±3% for relative humidity. The data based on rate of adsorption and the defined working condition was set as 20°C and 70% RH. Pore volume is a significant parameter for determining the limitation of water uptake, which can describe the saturated condition of zeolite. Sorption isotherm models used to describe sorption phenomena are commonly deduced from the Polanyi potential theory were investigated. The water adsorption quantity increased with the increase of relative pressure. To sum up, this pure zeolite has a less heat and mass transfer performance so its need to be activated before using in cooling application to get their great potential and by being coated in a desiccant heat exchanger systems.

  10. Removal of Sulphate and Manganese on Synthetic Wastewater in Sulphate Reducing Bioreactor Using Indonesian Natural Zeolite

    Directory of Open Access Journals (Sweden)

    Endah Retnaningrum

    2017-07-01

    Full Text Available The present research was conducted to investigate sulphate and manganese removal from synthetic wastewater. The continuous laboratory scale of down-flow fluidized-bed reactor (DFBR using sulphate reducing bacteria (SRB consortium and Indonesian natural zeolite as a bacterial support material was designed. At 9 days operation, maximum sulphate and manganese removal was observed to be 23% and 15.4%, respectively. The pH values were also changed to neutral. The population of SRB increased which effect on the raising of their activity for removing sulphate and manganese. Using the scanning electronic microscopy (SEM, it was observed that natural zeolite possesses excellent physical characteristics as a bacterial support material in DFBR. The imaging SEM result of SRB consortium on zeolite surface clearly showed the developed SRB biofilm on that particle. Analysis result of EDX confirmed that manganese was precipitated as manganese–sulfides.

  11. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  13. Processing of radioactive waste solution with zeolites, (4)

    International Nuclear Information System (INIS)

    Mimura, Hitoshi; Kanno, Takuji

    1978-01-01

    Volatilization of Cs from Cs type zeolites and calcined zeolites were studied at high temperature. Synthetic zeolites A, X, Y, synthetic mordenite (Zeolon), natural mordenite and clinoptilolite saturated with Cs were used in this study. Volatilized Cs from CsX was largest in quantity and from cs type natural zeolites smallest. Volatilization of Cs was observed at about 800 0 C and increased as the calcining temperature rose. Volatilized Cs from CsA was smallest in synthetic zeolites. CsA recrystallized to nepheline and pollucite with the ratio of about 1 : 1 above 1,000 0 C and it seemed that the volatilization of Cs from pollucite was suppressed with the nepheline phase surrounded them. The rate of volatilization was very fast within the initial 10 min and very slow after 60 min except for CsX. This behavior suggested that the rate was very fast before structural transformation. The mean volatilization rate of Cs in 3 hr from calcined CsX (pollucite) was 1.1 x 10 -4 mg/cm 2 .min and the others were 10 -5 -- 10 -6 mg/cm 2 .min. The amount of volatilized Cs in Ar flow was decreased 20 -- 90% of that in air flow. Volatilized species was identified with Cs 2 O by mass spectrometry. (auth.)

  14. 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.

  15. 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)

  16. 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.

  17. 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.

  18. Preliminary assessment of clinoptilolite K/Ar results from Yucca Mountain, Nevada: A potential high-level radioactive waste repository site

    International Nuclear Information System (INIS)

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

    1992-01-01

    At Yucca Mountain, evidence for at least three distinct temporal groups of clinoptilolites can be delineated from the preliminary K/Ar dates (2--3 Ma; 4--5 Ma; 7--11 Ma). The older K/Ar dates that are similar to published illite/smectite ages (9--12 Ma) may be crystallization ages, whereas the younger dates probably represent continued diagenetic reactions of older clinoptilolites with percolating fluids. The K/Ar dates increase with depth, suggesting minimal argon loss in the deeper samples. Internal consistency of the clinoptilolite K/Ar results at different levels within the drill holes suggest that dating of K-rich zeolites may provide useful information for assessing the zeolitization at Yucca Mountain. Variations in the K/Ar dates are probably related to Ar loss during dissolution of older clinoptilolites and to contamination by finely crystalline feldspars

  19. 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

  20. 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

  1. 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).

  2. 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

  3. Physical and mechanical properties of sand stabilized by cement and natural zeolite

    Science.gov (United States)

    Salamatpoor, Sina; Jafarian, Yaser; Hajiannia, Alborz

    2018-05-01

    Loose sands are prone to lose their shear strength when being subjected to static or cyclic loads. To this end, there exist several methods to improve the mechanical properties of sands, but the most crucial and viable approach is the one with the lowest harmful environmental impact both in production and recycling processes. In this regard, zeolite as a natural pozzolanic additive offers an eco-friendly improvement in strength parameters of cemented sandy soils. Thereby, in this study, a series of unconfined compressive strength (UCS) tests are conducted to evaluate the mechanical parameters of the zeolite-cemented sand. The results demonstrate a meaningful increase in the UCS of the treated sand samples for replacement of cement by zeolite at an optimum proportion of 40% in specimens with 14 and 28 days curing time. The effectiveness of the improvement process is demonstrated by the strength improvement ratio which was up to be 128% to 209% for the samples with 14 and 28 days curing time, respectively. With regard to the above results, zeolite can be introduced as a promising cement substitute in stabilization of sandy ground including backfills, roadbed, embankments, and other structural filling systems.

  4. Metal supported on natural zeolite as catalysts for conversion of ethanol to gasoline

    Directory of Open Access Journals (Sweden)

    Kristiani Anis

    2017-01-01

    Full Text Available A various of metal supported into natural zeolite was prepared via wet impregnation method. The transition metals impregnated are nickel, cobalt, copper and zinc. The catalytic properties both of physical and chemical properties were characterized by X-ray Diffraction (XRD, Thermo Gravimetri Analysis (TGA-Differential Scanning Calorimetry (DSC, Surface Area Analyzer-Porositymeter and also gravimetry method for acidity measurement following by the adsorption of organic bases. The results showed that different metals impregnated into natural zeolite affected physical and chemical properties, i.e. crystalinity, surface area, pore size, pore volume and acidity. Their catalytic activity was tested for conversion ethanol to gasoline and showed high conversion up to 80-90% with the aromatics as major product.

  5. 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.

  6. Bacterial biofilm supported on granular activated carbon and on natural zeolites- an application to wastewater treatment

    OpenAIRE

    Lameiras, Sandra Raquel de Vasconcelos; Quintelas, C.; Tavares, M. T.

    2004-01-01

    The removal of many heavy metals from industrial wastewater is one of the most important environmental problems to be solved today. The retention of this contaminants by a biofilm supported on granular activated carbon or on natural zeolites is one of the promising technologies for the reduction of this problem, because it is cheap and it removes a broad range of substances, heavy metals and organic compounds. This study aims the development of a system of two mini-columns in series ...

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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.;

  16. 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.

  17. Evaluation of the potentiality of a Mexican natural zeolite chabazite-type in the lead removal in water

    International Nuclear Information System (INIS)

    Alvarado I, J.; Sotelo L, M.; Meza F, D.; Paz M, F. A.; Maubert F, M.

    2013-01-01

    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 4 NO 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 2 =0.92), which demonstrates that natural zeolites studied, in its natural form, contains exchangeable cations required (Ca +2 , Mg 2+ and Na + ) for potentially be used as an adsorbent material/ion exchanger for water treatment impacted by lead. (Author)

  18. Catalytic Ozonation of Toluene Using Chilean Natural Zeolite: The Key Role of Brønsted and Lewis Acid Sites

    Directory of Open Access Journals (Sweden)

    Serguei Alejandro-Martín

    2018-05-01

    Full Text Available The influence of surface physical-chemical characteristics of Chilean natural zeolite on the catalytic ozonation of toluene is presented in this article. Surface characteristics of natural zeolite were modified by acid treatment with hydrochloric acid and ion-exchange with ammonium sulphate. Prior to catalytic ozonation assays, natural and chemically modified zeolite samples were thermally treated at 623 and 823 K in order to enhance Brønsted and Lewis acid sites formation, respectively. Natural and modified zeolite samples were characterised by N2 adsorption at 77 K, elemental analysis, X-ray fluorescence, and Fourier transform infrared (FTIR spectroscopy, using pyridine as a probe molecule. The highest values of the reaction rate of toluene oxidation were observed when NH4Z1 and 2NH4Z1 zeolite samples were used. Those samples registered the highest density values of Lewis acid sites compared to other samples used here. Results indicate that the presence of strong Lewis acid sites at the 2NH4Z1 zeolite surface causes an increase in the reaction rate of toluene oxidation, confirming the role of Lewis acid sites during the catalytic ozonation of toluene at room temperature. Lewis acid sites decompose gaseous ozone into atomic oxygen, which reacts with the adsorbed toluene at Brønsted acid sites. On the other hand, no significant contribution of Brønsted acid sites on the reaction rate was registered when NH4Z1 and 2NH4Z1 zeolite samples were used.

  19. The Effects of Natural Zeolit Supplemented into Litter on Growth Performance and Welfare of Broilers

    OpenAIRE

    Erol BİNTAŞ; Kamil Küçükyılmaz; Mehmet Bozkurt; Abdullah Uğur Çatlı; Mustafa Çınar; Sabri Topbaş; Bahattin Koçer; Gökhan Ege

    2014-01-01

    The objective of this study was to assess the effect of clinoptiolite (a natural zeolite) in two addition level (3 kg or 6 kg) and two particle size (ranging from 0.1 to 0.2 mm or 0.5 to 1.0 mm) as litter supplement on the growth performance, litter dry matter, ammonium release and foot pad lesion score of broilers. One thousand and eight hundred, one-day-old chickens were divided into five treatment groups with six replicates of 60 chicks. Bird density was 15/ m2 in floor pens where pine sha...

  20. Pyrolysis of polyethylene terephthalate containing real waste plastics using Ni loaded zeolite catalysts

    Science.gov (United States)

    Al-asadi, M.; Miskolczi, N.

    2018-05-01

    In this work the pyrolysis of polyethylene terephthalate (PET) containing real waste plastic was investigated using different Ni loaded catalysts: Ni/ZSM-5, Ni/y-zeolite, Ni/β-zeolite and Ni/natural zeolite (clinoptilolite). Raw materials were pyrolyzed in a horizontal tubular reactor between 600 and 900°C using 10% of catalysts. It was found, that both temperature increasing and catalysts presence can increase the gas yields, however owing to gasification reactions, the pyrolysis oil yield decreased with increasing temperature. Ni/y-zeolite catalyst had the most benefit in gas yield increasing at low temperature; however Ni/ZSM-5 showed advanced property in gas yield increasing at high temperature. Gases contained hydrogen, carbon oxides and hydrocarbons, which composition was significantly affected by catalysts. Ni loaded zeolites favoured to the formation of hydrogen and branched hydrocarbons; furthermore the concentrations of both CO and CO2 were also increased as function of elevated temperature. That phenomenon was attributed to the further decomposition of PET, especially to the side chain scission reactions. Owing to the Boudouard reaction, the ratio of CO2/CO can increased with temperature. Pyrolysis oils were the mixtures of n-saturated, n-unsaturated, branched, oxygen free aromatics and oxygenated hydrocarbons. Temperature increasing has a significant effect to the aromatization and isomerization reactions, while the catalysts can efficiently decreased the concentration of oxygen containing compounds.

  1. Zeolite from Cikancra Tasikmalaya, West Java: a review of its properties

    International Nuclear Information System (INIS)

    Estiaty, Lenny Marilyn; Prijatama, Herry; Zulkarnain, Iskandar; Kurnia, Dewi F.; Nurlela, Iis; Goto, Yoshiaki; Szuciya

    2002-01-01

    Samples from natural zeolite deposit in Cikancra village, Tasikmalaya, West Java were investigated for its main properties. Chemical composition was analyzed by X-ray Fluorescence (XRF) and Atomic Absorption Spectrometry (AAS) methods. Mineralogical analyses were carried out using X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) methods. Furthermore, continuous flow method was applied for cation exchange capacity (CEC) determination and TG-DTA (thermal gravimetry - differential thermal analysis) was carried out to see the thermal behaviour of the zeolite. Analysis results showed that the chemical composition was dominated by silica and alumina, while other elements like sodium, iron, potassium and titanium were present in lesser amounts. The sellite type was identified as mordenite and depopulation. SEM photographs indicated crystals of mordenite in fibrous or needle forms and platy clinoptilolite. Zeolite Cikancra was also found to have a relatively high exchange capacity with a CEC value of 143.58 meq/100 g. Thermal analysis revealed that water vapor was released from zeolite at temperature of 80.5 to 148 oC with a weight loss of 9.4%. Furthermore, crystal water was released at 481.8 oC , which was indicated with a weight loss of 4.3%. Based on those determined properties, Zeolite Cikancra has the ability to be used for wastewater treatment, agriculture or animal nutrient applications, drying and odorless

  2. The performance of BAF using natural zeolite as filter media under conditions of low temperature and ammonium shock load

    International Nuclear Information System (INIS)

    He Shengbing; Xue Gang; Kong Hainan

    2007-01-01

    Natural zeolite and expanded clay were used as filter media for biological aerated filter (BAF) to treat municipal wastewater in parallel in whole three test stages. The stage one test results revealed that zeolite BAF and expanded clay BAF have COD and NH 3 -N removals in the range of 84.63-93.11%, 85.74-96.26%, 82.34-93.71%, and 85.06-93.2%, respectively, under the conditions of water temperature of 20-25 deg. C and hydraulic load of 2-3 m 3 /(m 2 h). At the following stage two, the influent NH 3 -N concentration was increased to about double value of the stage one, and it was investigated that the effluent NH 3 -N of expanded clay BAF increased significantly and then gradually restored to normal condition in 2 weeks, while the effluent NH 3 -N of zeolite BAF kept stable. At stage three, the low reactor temperature has also different effects on these two BAFs, under conditions of water temperature of 7-10 deg. C, hydraulic load of 2-3 m 3 /(m 2 h), zeolite BAF and expanded clay BAF have COD and NH 3 -N removals in the range of 74.5-88.47% (average of 81.57%), 71.73-88.49% (average of 81.06%), 71.91-87.76% (average of 80.49%), and 38.41-77.17% (average of 65.42%), respectively. Three stages test results indicated that the zeolite BAF has a stronger adaptability to NH 3 -N shock load and low temperature compared to expanded clay BAF. In addition, the detection of the amounts of heterobacteria and nitrobacteria of two biological aerated filters in three stages also showed the zeolite filter media was more suitable to the attached growth of nitrobacteria, which is helpful to the improvement of nitrification performance in zeolite BAF

  3. Ion-exchange properties of cesium and strontium into zeolites from sodium salt solutions

    International Nuclear Information System (INIS)

    Kanno, Takuji; Hashimoto, Hiroyuki; Ohtani, Tozo.

    1978-01-01

    The ion-exchange properties of cesium and strontium into zeolite from sodium salt solution has been studied in zeolite A, zeolite X, zeolite Y, mordenite and clinoptilolite. The distribution of cesium into mordenite from about 1 -- 2 M sodium chloride and sodium hydroxide solutions is considerably larger than that into zeolite A. The distribution coefficient for 2 M solution of sodium salts was about 300. Therefore, the separation of cesium from sodium salt solution is possible by using mordenite. The distribution of strontium into zeolites form 1 -- 2 M solutions of sodium chloride and sodium nitrate were in the order of zeolite A>zeolite X>zeolite Y asymptoticaly equals mordenite. The distribution coefficient of 230 was obtained for 1 M solutions of sodium salts. The anion in solutions had no effect on the distribution of cesium and strontium into zeolite from sodium salt solution. (author)

  4. The selective separation of Cs and Sr ion on the inorganic ion-exchanger zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hun Hwee; Min, Byeog Heon [Hoseo University, Taegu (Korea)

    1998-04-01

    This study shows the selective separation of Cs and Sr ion on the inorganic ion-exchanger zeolites such as clinoptilolite, Y-type CBV760, CBV780 and A-type 3A. The selective separation of Cs and Sr on these zeolites was examined using batch and continuous column experiments. For the selective separation of Cs and Sr from a synthetic wastewater, adsorption rate of Cs increased in the order, clinoptilolite> 3A>> CBV760> CBV780, adsorption rate of Sr increased in the other, 3A>> clinoptilolite> CBV760> CBV780. For the clinoptilolite, the adsorption rate of Cs reached about 96 {approx} 98% within 3h. The adsorption rate of Sr on 3A reached about 99% within 3h. (author). 40 refs., 27 figs., 4 tabs.

  5. Use of zeolites for the removal of volatile sulfur compounds from industrial waste gases and from natural gases

    Energy Technology Data Exchange (ETDEWEB)

    Dudzik,; Z,; Bilska, M

    1974-12-01

    The use of zeolites for the removal of sulfur dioxide from industrial waste gases and for the removal of hydrogen sulfide and volatile mercaptans from the natural gas or synthetic gas manufactured from coal is discussed. The effectiveness and cost of zeolite methods are superior to that of other methods. The best sorption properties with respect to sulfur dioxide are observed in faujasites and erionites. The molecular sieve 13X (a sodium form of low-silicon faujasite) is the most effective sorbent of hydrogen sulfide, produced commercially on a large scale. This zeolite is also a very effective catalyst for simultaneous oxygenation of hydrogen sulfide. The reaction with oxygen can begin at temperatures as low as -80/sup 0/C. The effectiveness of zeolite reactors is enhanced by the presence of oxygen in the gas being purified, and is hindered by the presence of water or water vapor. The extraordinary catalytic activity of sodium faujasites is due to free donors, and sulfur and oxygen ion donors at their surface. A zeolite reactor is also economical.

  6. 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.

  7. Sorption of Cs-137 and Co-60 in Natural Zeolites; Sorcion de Cs-137 y Co-60 en zeolitas naturales

    Energy Technology Data Exchange (ETDEWEB)

    Chales Suarez, G; Moreno Alvarez, D; Coutin Correa, D [Agencia de Energia Nuclear, La Habana (Cuba)

    1996-07-01

    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.

  8. Denitration of simulated high-level liquid wastes and selective removal of cesium with zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Mimura, Hitoshi; Kanno, Takuji [Tohoku Univ., Sendai (Japan). Research Inst. of Mineral Dressing and Metallurgy; Kimura, Toshiya

    1982-03-01

    Denitration of high-level liquid wastes (HLW) from nuclear fuel reprocessing has been studied. Selective removal of Cs has been also examined with various types of zeolites. The following zeolites were used in this study; Na-synthetic mordenite (NaSM), Na-natural mordenite (NaNM), Na-natural clinoptilolite (NaCP) and H-synthetic mordenites (HSM). The effective denitration is found in the simulated HLW (15 components, 2N HNO/sub 3/ soln.) containing platinum group elements in the case of the addition of formic acid, and the pH of the solution shows the value of 5.4 when the excess formic acid ((HCOOH)/(HNO/sub 3/) = 2.0) was added. Platinum group elements may react as a catalyst for the decomposition of nitric acid and the excess formic acid. The break-through properties of NaSM column are poor for the simulated HLW, and the selective removal of Cs appears to be difficult. On the other hand, good results are obtained in the denitrated HLW, i.e., break-through capacity, total capacity and column utilization are 59.4 (meq./100 g zeolite), 147 (meq./100 g zeolite) and 40.4 (%), respectively. The break-through properties of NaSM and NaNM are superior to those of HSM. The break-through capacity and column utilization increase with an increase in column temperature.

  9. Denitration of simulated high-level liquid wastes and selective removal of cesium with zeolites

    International Nuclear Information System (INIS)

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

    1982-01-01

    Denitration of high-level liquid wastes (HLW) from nuclear fuel reprocessing has been studied. Selective removal of Cs has been also examined with various types of zeolites. The following zeolites were used in this study; Na-synthetic mordenite (NaSM), Na-natural mordenite (NaNM), Na-natural clinoptilolite (NaCP) and H-synthetic mordenites (HSM). The effective denitration is found in the simulated HLW (15 components, 2N HNO 3 soln.) containing platinum group elements in the case of the addition of formic acid, and the pH of the solution shows the value of 5.4 when the excess formic acid ([HCOOH]/[HNO 3 ] = 2.0) was added. Platinum group elements may react as a catalyst for the decomposition of nitric acid and the excess formic acid. The break-through properties of NaSM column are poor for the simulated HLW, and the selective removal of Cs appears to be difficult. On the other hand, good results are obtained in the denitrated HLW, i.e., break-through capacity, total capacity and column utilization are 59.4 (meq./100 g zeolite), 147 (meq./100 g zeolite) and 40.4 (%), respectively. The break-through properties of NaSM and NaNM are superior to those of HSM. The break-through capacity and column utilization increase with an increase in column temperature. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Babaahamdi-Milani, Majid [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)

    2016-11-15

    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{sub 1.3%}–PbO{sub 14.7%}-NCP and NiS{sub 2.1%}–PbS{sub 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{sup −1} photocatalysts, 15 mg L{sup −1} 4-NP at pH 7.5.

  11. 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)

  12. 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)

  13. 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.

  14. 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

  15. Clean-up of liquid radiation wastes with elevated mineralization from cesium and cobalt radionuclides by the modified clinoptilolite of the Chankanaj deposit

    International Nuclear Information System (INIS)

    Plotnikov, V.I.; Tuleushev, A.Zh.; Zhabykbaev, G.T.; Kostsov, S.V.; Medvedeva, Z.V.; Plotnikova, O.M.; Chakrova, E.T.; Idrisova, U.R.; Idrisova, D.Zh.

    2003-01-01

    On the base of laboratory studies and semi-industrial testing the possibility of liquid radioactive wastes clean-up from cesium and cobalt radionuclides in elevated mineralization conditions with help of modified clinoptilolite is shown. In the work the synthesized thin-layer inorganic sorbent (TIS) with conventional name MC-2 (modified clinoptilolite) was used. The Chankanaj deposit's zeolite in the crushed form was base for the TIS production. The copper ferrocyanides serves as the modifier. This sorbent is selective one in relationship to cesium and cobalt radionuclides

  16. ESSENTIAL OILS AND NATURAL ZEOLITE INFLUENCE ON PRODUCTION AND HEALTH PERFORMANCE OF BROILERS, AND MICROBIOLOGICAL CONTAMINATION OF CHICKEN MEAT

    Directory of Open Access Journals (Sweden)

    Brigita Hengl

    2013-12-01

    Full Text Available Essential oils and their components, as a group of phytogenic feed additive, have great potential uses in broiler fattening. Due to their antimicrobial and antioxidant properties and effects on improved food digestibility their positive impact on animals the health status can be expected, and therefore better final fattening results. In this research we studied the impact of XTRACTTM (a combination of essential oils components carvacrol, cinnamaldehid and capsicum Oleoresin, Arom Korm ® (essential oil combination of Foeniculum vulgare and Citrus limon, zeolite and a combination of zeolite with XTRACTTM or Aroma Korma ® on the fattening performance of chickens, their immunostimulating effect, the impact on the antioxidant status of the blood and muscle tissue, the impact on intestine micropopulation of chickens, effect on microbial contamination of meat, the impact on processing performances of broiler chicken and meat properties, and impact on the sensory quality of the chicken meat. The experiment was conducted on Ross 308 broilers, divided into 6 groups (control and treatment groups depending on the different supplements of essential oils, zeolites, or combinations thereof. The fattening lasted 42 days and total of 288 both sex chicks were included (48 per in each group. Influence of the addition of essential oils and natural zeolite had a different impact on the observed individual values. Separately added XTRACTTM and Aroma Korm ® had a good effect on the observed properties of fattening, the technological properties of meat, chicken health status, antioxidant parameters of blood and meat, microbiological contamination and organoleptic properties. Zeolite, as a standalone supplement, had the lowest impact on the observed properties, but in combination with Aroma Korm ® or XTRACTTM, Zeolite improved their activity.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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)

  3. Using natural Chinese zeolite to remove ammonium from rainfall runoff following urea fertilization of a paddy rice field.

    Science.gov (United States)

    Wang, Xiao-Ling; Qiao, Bin; Li, Song-Min; Li, Jian-Sheng

    2016-03-01

    The potential of natural Chinese zeolite to remove ammonium from rainfall runoff following urea applications to a paddy rice field is assessed in this study. Laboratory batch kinetic and isotherm experiments were carried out first to investigate the ammonium adsorption capacity of the natural zeolite. Field experiments using zeolite adsorption barriers installed at drain outlets in a paddy rice field were also carried out during natural rainfall events to evaluate the barrier's dynamic removal capacity of ammonium. The results demonstrate that the adsorption kinetics are accurately described by the Elovich model, with a coefficient of determination (R (2)) ranging from 0.9705 to 0.9709, whereas the adsorption isotherm results indicate that the Langmuir-Freundlich model provides the best fit (R (2) = 0.992) for the equilibrium data. The field experiments show that both the flow rate and the barrier volume are important controls on ammonium removal from rainfall runoff. A low flow rate leads to a higher ammonium removal efficiency at the beginning of the tests, while a high flow rate leads to a higher quantity of ammonium adsorbed over the entire runoff process.

  4. 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)

  5. Cr(VI) retention and transport through Fe(III)-coated natural zeolite

    Energy Technology Data Exchange (ETDEWEB)

    Du, Gaoxiang [School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Li, Zhaohui, E-mail: li@uwp.edu [School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Geosciences Department, University of Wisconsin-Parkside, Kenosha, WI 53144 (United States); Department of Earth Sciences, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China); Liao, Libing [School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Hanson, Renee; Leick, Samantha; Hoeppner, Nicole [Geosciences Department, University of Wisconsin-Parkside, Kenosha, WI 53144 (United States); Jiang, Wei-Teh [Department of Earth Sciences, National Cheng Kung University, 1 University Road, Tainan 70101, Taiwan (China)

    2012-06-30

    Graphical abstract: Breakthrough curves of Cr(VI) from columns packed with raw zeolite (a) and Fe(III)-zeolite (b). The solid line in (b) is the HYDRUS-1D fit to the observed data with adsorption term only, while the dashed line in (b) includes a reduction term in the HYDRUS-1D fit. Highlights: Black-Right-Pointing-Pointer Zeolite modified with Fe(III) could be used for adsorption and retention of Cr(VI). Black-Right-Pointing-Pointer The Fe present on zeolite was in an amorphous Fe(OH){sub 3} form. Black-Right-Pointing-Pointer A Cr(VI) adsorption capacity of 82 mg/kg was found on Fe(III)-zeolite. Black-Right-Pointing-Pointer A Cr(VI) retardation factor of 3 or 5 was determined from column and batch studies. - Abstract: Cr(VI) is a group A chemical based on the weight of evidence of carcinogenicity. Its transport and retention in soils and groundwater have been studied extensively. Zeolite is a major component in deposits originated from volcanic ash and tuff after alteration. In this study, zeolite aggregates with the particle size of 1.4-2.4 mm were preloaded with Fe(III). The influence of present Fe(III) on Cr(VI) retention by and transport through zeolite was studied under batch and column experiments. The added Fe(III) resulted in an enhanced Cr(VI) retention by the zeolite with a capacity of 82 mg/kg. The Cr(VI) adsorption on Fe(III)-zeolite followed a pseudo-second order kinetically and the Freundlich adsorption isotherm thermodynamically. Fitting the column experimental data to HYDRUS-1D resulted in a retardation factor of 3 in comparison to 5 calculated from batch tests at an initial Cr(VI) concentration of 3 mg/L. The results from this study showed that enhanced adsorption and retention of Cr(VI) may happen in soils derived from volcanic ash and tuff that contains significant amounts of zeolite with extensive Fe(III) coating.

  6. 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

  7. Natural sorbents as barriers against migration of radionuclides from radioactive waste repositories

    International Nuclear Information System (INIS)

    Stefanova, I.; Gradev, G.D.

    1993-01-01

    The sorption properties of Bulgarian inorganic sorbents - clinoptilolite, vermiculite, bentonite, glauconite, celadonite and loess, which can be used as buffer, backfill and sealing materials in radwaste repository are studied. Experimental data about sorption and desorption capacities, radiation and thermal stability of sorbents from different Bulgarian deposits are reported and compared. Clinoptilolite from Beli Plast and its sodium variety from Kostino and Moryantsi is recommended as a barrier against radionuclide migration from radwaste repository due to their high sorption capacity of 137 Ce, 90 Sr and 60 Co. The high selectivity of vermiculite for polyvalent ions ( 144 Ce, 59 Fe and 90 Sr) gives grounds to include the sorption on vermiculite as a second step in the ion exchange technology for low level laundry waste decontamination. Bentonite is studied as a proposed buffer, backfill and sealing material. Its selectivity for cesium is lower compared to those of clinoptilolite. Thus a tailored-made mixture of bentonite and clinoptilolite will act as a barrier against radionuclides in different oxidation state. Glauconite can be successfully used as a barrier against migration of 144 Ce, 90 Sr, 54 Mn and 65 Zn. Loess is also included in the study, as the Kozloduy NPP is sited on loess formation and it is a natural potential site for low and intermediate level waste burial. It is concludes that zeolites and clays of Bulgarian deposits can be used effectively against radionuclide migration from radioactive waste repositories. 59 refs., 5 tabs. (author)

  8. 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.

  9. 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)

  10. Lampung natural zeolite filled cellulose acetate membrane for pervaporation of ethanol-water mixtures

    Science.gov (United States)

    Iryani, D. A.; Wulandari, N. F.; Cindradewi, AW; Ginting, S. Br; Ernawati, E.; Hasanudin, U.

    2018-03-01

    Pervaporation of ethanol–water can be cost-competitive in the production of renewable biomass ethanol. For the purpose of improving the pervaporation performance of polymeric membranes, we prepared cellulose acetate (CA) filled Lampung Natural Zeolite (LNZ) membranes by incorporating LNZ into CA for pervaporation separation of ethanol-water mixtures. The characteristics and performance of these filled membranes in the varied ratio of CA:LNZ (30:0, 30:5, 30:10, 30: 20, 20:20 and 40:10) wt% were investigated. The prepared membranes were characterized for pervaporation membrane performance such as %water content and membrane swelling degree. Further, the permeation flux and selectivity of membrane were also observed. The results of investigation show that water content of membrane tends to increase with increase of LNZ content. However, the swelling degree of membrane decrease compared than that of CA control membrane. The permeation flux and the selectivity of membranes tend to increase continuously. The CA membrane with ratio of CA:LNZ 30:20 shows the highest selectivity of 80.42 with a permeation flux of 0.986 kg/(m2 h) and ethanol concentration of 99.08 wt%.

  11. Toluene, Methanol and Benzaldehyde Removal from Gas Streams by Adsorption onto Natural Clay and Faujasite-Y type Zeolite.

    Science.gov (United States)

    Zaitan, Hicham; Mohamed, Elham F; Valdés, Héctor; Nawdali, Mostafa; Rafqah, Salah; Manero, Marie Hélène

    2016-12-01

    A great number of pollution problems come as a result of the emission of Volatile Organic Compounds (VOCs) into the environment and their control becomes a serious challenge for the global chemical industry. Adsorption is a widely used technique for the removal of VOCs due to its high efficiency, low cost, and convenient operation. In this study, the feasibility to use a locally available clay, as adsorbent material to control VOCs emissions is evaluated. Natural clay is characterised by different physical-chemical methods and adsorptive interaction features between VOCs and natural clay are identified. Toluene (T), methanol (M) and benzaldehyde (B) are used here as representatives of three different kinds of VOCs. Adsorption isotherms onto natural clay and faujasite-Y type zeolite (Fau Y) are obtained at room temperature. According to Langmuir model data, maximum adsorption capacities (qm) of Fez natural clay and zeolite toward methanol (M), toluene (T) and benzaldehyde (B) at 300 K are 8, 0.89 and 3.1 mmol g-1, and 15, 1.91 and 13.9 mmol g-1 respectively. In addition, the effect of temperature on the adsorption of toluene onto natural clay is evaluated in the range from 300 to 323K. An increase on temperature reduces the adsorption capacity of natural clay toward toluene, indicating that an exothermic physical adsorption process takes place. The enthalpy of adsorption of toluene onto Fez natural clay was found to be -54 kJ mol-1. A preliminary cost analysis shows that natural clay could be used as an alternative low cost adsorbent in the control of VOCs from contaminated gas streams with a cost of US$ 0.02 kg-1 compared to Fau Y zeolite with US$ 10 kg-1.

  12. 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.

  13. Effect of cation nature on development of Zn-, Cd- and Ca-zeolite catalysts during ethylbenzene transformations

    International Nuclear Information System (INIS)

    Tuan, K.Kh.; Berentsvejg, V.V.; Rudenko, A.P.; Tkhuan, N.T.; Topchieva, K.V.

    1984-01-01

    It is shown that in the course of ethylbenzene transformations at 650 deg, 0.25 7nY, 0.25CdY, 0.82CdY catalysts on the basis of Y-type zeolite are developed for the process of styrene formation accompanied by the accumulation of packing products (PP) and increase in styrene selectivity from 0 to 100%. It is shown that the nature of Me 2+ ion in zeolite is of great importance in the manifestation of the effect of catalyst development in the course of ethylbenzene transformations. Ions capable of PP formation and accumulation composing polymercatalyst complexes [PPxMe 2+ ] are active in this process

  14. The spectroscopic study of building composites containing natural sorbents.

    Science.gov (United States)

    Król, M; Mozgawa, W

    2011-08-15

    This work presents the results of FT-IR spectroscopic studies of heavy metal cations (Ag(+), Pb(2+), Zn(2+), Cd(2+) and Cr(3+)) immobilization from aqueous solutions on natural sorbents. The sorption has been conducted on sodium forms of zeolite (clinoptilolite) and clay minerals (mixtures containing mainly montmorillonite and kaolinite) which have been separated from natural Polish deposit. In the next part of the work both sorbents were used to obtain new building composites. It was proven those heavy metal cations' sorption causes changes in IR spectra of the zeolite and clay minerals. These alterations are dependent on the way the cations were sorbed. In the case of zeolite, variations of the bands corresponding to the characteristic ring vibrations have been observed. These rings occur in pseudomolecular complexes 4-4-1 (built of alumino- and silicooxygen tetrahedra) which constitute the secondary building units (SBU) and form spatial framework of the zeolite. The most significant changes have been determined in the region of pseudolattice vibrations (650-700 cm(-1)). In the instance of clay minerals, changes in the spectra occur at two ranges: 1200-800 cm(-1)--the range of the bands assigned to asymmetric Si-O(Si,Al) and bending Al-OH vibrations and 3800-3000 cm(-1)--the range of the bands originating from OH(-) groups stretching vibrations. Next results indicate possibilities of applying the used natural sorbents for the obtainment of new building materials having favourable composition and valuable properties. The zeolite was used for obtaining autoclaved materials with an addition of CaO, and the clay minerals for ceramic sintered materials with an addition of quartz and clinoptilolite were produced. FT-IR studies were also conducted on the obtained materials. Copyright © 2010 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    Barbosa, Gustavo P; Debone, Henrique S; Severino, Patrícia; Souto, Eliana B; da Silva, Classius F

    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.

  16. 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

  17. 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.

  18. Wastewater treatment from heavy metal ions using nanoactivated complexes of natural zeolite and diatomite

    Directory of Open Access Journals (Sweden)

    Malkin Polad

    2018-04-01

    Full Text Available Despite the wide practical use of sorption methods and complexones in treatment of industrial wastewater, some problems are still to be solved in this field. These are the most significant: insufficient sorption capacity of materials, lack of reliable methods for regenerating sorbents and resource-saving ecology friendly treatment technologies with the use of sorbents as well as methods of utilization of heavy metals from waste by complex formation. An important factor affecting the behavior of heavy metals in the soil is the medium acidity. With a neutral and slightly alkaline reaction of the medium, hardly soluble compounds are formed: hydroxides, sulphides, phosphates, carbonates, and oxalates of heavy metals. When acidity increases the reverse process runs in the soil: hardly soluble compounds become more mobile, while mobility of many heavy metals increases. However, the effect of soil acidity on mobility of heavy metals is ambiguous. Although mobility of many heavy metals decreases with increasing pH of the medium (for example, Fe, Mn, Zn, Co, etc., there are a number of metals whose mobility increases with soil neutralization. These include molybdenum and chromium, which are able to form soluble salts in a weak ly acidic and alkaline medium. In addition, heavy metals such as mercury and cadmium are able to maintain mobility in an alkaline medium through formation of complex compounds with organic matter in soils. Heavy metals interact with a solid phase of the soil by mechanisms of specific and nonspecific adsorption. In this article, a technique of wastewater treatment from heavy metal ions using nanoactivated complexes of natural zeolite and diatomite is proposed. This technique can reduce significant costs in preparation of raw materials and subsequent chemical modification of them. Technological solutions aimed at disposal and recycling of industrial wastewater have been proposed. These solutions make it possible to obtain the water

  19. 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

  20. Procedure for the reversible confinement of gases or vapours in a natural or synthetic zeolite

    International Nuclear Information System (INIS)

    1980-01-01

    The zeolite is treated with silane at a temperature of 100-140 0 C to silanise it in the H-form. This narrows the pores in the zeolite and the grains bind together creating cavities. The silanised zeolite and the material to be confined are brought into contact at high pressure, for example at an excess pressure of 0.5 atm. Contact is continued until the required quantity of gas or vapour has been adsorbed by the zeolite. Under the same high pressure water is added to the system which causes further narrowing of the pores. Preferably the process of silanising and treating with water is then repeated one or more times to close the pores and ensure confinement. The process is reversed by heating the product above 300 0 C. The bonds formed by silanising are then broken and the confined material is liberated. This process has applications in the confinement of valuable gases such as enriched isotopes, and of dangerous gases such as radioactive waste gases. (Th.W.P.)

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

    International Nuclear Information System (INIS)

    Barbosa, Gustavo P.; Debone, Henrique S.; Severino, Patrícia; Souto, Eliana B.; Silva, Classius F. da

    2016-01-01

    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.

  2. 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.

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

    Directory of Open Access Journals (Sweden)

    Wahjuningsih Nurul

    2018-01-01

    Full Text Available 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. 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.

  5. Isomerization of α-pinene in the terpentin oil with TCA/Natural Zeolite using microwave irradiation

    Science.gov (United States)

    Wijayati, N.; Supartono; Kusumastuti, E.

    2018-04-01

    The catalytic potensial of trichloroacetic acid (TCA)//Natural Zeolite in the isomerization of α-pinene in the terpentin oil was investigated. The purpose of this study is to investigate the influence of the power of microvawe on activity and selectivity of catalyst. The main product were champhene, terpinene, limonene, p-cymene, and terpinolene. The highest selectivity was 28.26% with a conversion of 23.25%, whereas the higher conversion was 98.99% with selectivity of 16.90% at room temperature using power of microwave 640 W.

  6. Solid diffusion control of the adsorption of basic dyes onto granular activated carbon and natural zeolite in fixed bed columns

    Directory of Open Access Journals (Sweden)

    M. MARINKOVSKI

    2001-07-01

    Full Text Available The adsorption of basic dyes from aqueous solutions onto granular activated carbon and natural zeolite was studied using a fixed bed column. The design procedures for fixed bed adsorption columns were investigated for two basic dyes Maxilon Goldgelb GL EC 400 % (MG-400 and Maxilon Schwarz FBL-01 300 % (MS-300. A computer program based on the solid diffusion control model has been developed. The model parameters: solid diffusion coefficient, DS, axial dispersion coefficient, DL and external mass transfer coefficient, kf for all the investigated systems were estimated by means of a best fit approach.

  7. 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.

  8. Infrared study of the nature of the copper ion--alkyne bond in Y zeolite

    International Nuclear Information System (INIS)

    Pichat, P.

    1975-01-01

    The infrared spectra of acetylene, deuterated acetylene, propyne, and but-2-yne, chemisorbed in Cu, Na--Y zeolites, which have undergone various treatments, were studied. It is concluded that the OH groups interact only with the weakly absorbed molecules, the Cu + ions are not involved, the acetylenic hydrogen atoms do not take part in the bonding, the Cu 2+ ion--alkyne bone results mainly from π donation from the unsaturated hydrocarbon to the metallic ion. (auth)

  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. 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%.

  11. 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.

  12. 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

  13. 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

  14. Anchoring of CoHFC nanoparticles on clinoptilolite for remedy of nuclear wastes

    Directory of Open Access Journals (Sweden)

    Yousefi Taher

    2017-01-01

    Full Text Available To improve the mechanical properties, the cobalt ferrocyanide precipitation was carried out on clinoptilolite as an inorganic polymer. In this work the combination of two important factors, stability (zeolite and high adsorption capacity (cobalt ferrocyanide were considered to improve the ions uptake ability of adsorbent. The modification was approved by X-ray diffraction, Scanning electronic microscopy and Fourier transform infrared spectroscopy. The modified zeolite was applied to remove Sr(II and Cs(I ions from aqueous solution in a batch system. The adsorption capacities of modified zeolite for Cs(I and Sr(II improved to 90 and 130 mgg-1, respectively. The Sr(II and Cs(I removal were investigated as a function of shaking time, pH, Sr(II, and Cs(I initial concentration and temperature. The experimental data were fitted well to Langmuir isotherm model for two sorbet metal ions. The time dependence sorption data showed that the uptakes of Cs(I and Sr(II were very rapid and apparent sorption equilibriums were achieved within 100 min of contact time. The kinetic experimental data were fitted to the pseudo-first order, pseudo-second order, the double exponential, Elovich and intraparticle diffusion models. The sorption rates and capacities as well as rate constants were evaluated.

  15. 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

  16. Zeolite studies. Aluminium phosphate zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Haegh, G.S.; Blindheim, U.

    1983-12-01

    Alpo-zeolites (ALPO4-zeolites) have been synthesized by hydrothermal synthesis in an autoclave from alumina, tetralkylammonium hydroxide and phosphorus acid. Catalysis tests with hydrocarbons indicate that the compounds have good olefinisomerization activity and selectivity.

  17. 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

  18. 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.

  19. Investigation of the mechanism of interaction at the hydrothermal conditions of zeolite – cubic analcime with the Li+, Mg2+, Sr2+ and Fe3+ ions

    Directory of Open Access Journals (Sweden)

    Asta TRAIDARAITĖ

    2013-09-01

    Full Text Available Analcime and clinoptilolite are among the most abundant zeolites in nature. During recent decades natural analcimes and clinoptilolites, also synthetic modified analcimes have been investigated as potential and innovative substances, possible to use for the immobilization of radioactive waste, molecular catalysis and other purposes. However, natural analcimes like many natural rocks are contamined with various impurities (about 30 %, which significally reduces their sorption possibilities and possibilities of their using in such chemical technologies as catalysis, fractioning of hydrocarbons and other. In this article the stability of cubic analcime at the hydrothermal conditions at 180 °C temperature in solutions of various concentrations, containing Li+, Mg2+, Sr2+ and Fe3+ ions has been examined. These processes have big signification for the formation of ion-exchanged analcimes, its sorption properties and also if ions have been immobilized in analcime structure. It has been established, that as result of interaction between cubic analcime and lithium chloride solutions the formation of new compounds: lithium silicate and silinaite occurs. At the same hydrothermal conditions the interaction between cubic analcime and chloride solutions, containing Sr2+, Mg2+ and Fe3+ ions pass without formation of new compounds, and only with interposition of these ions in the structure of cubic analcime. DOI: http://dx.doi.org/10.5755/j01.ms.19.3.1496

  20. 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.

  1. 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.

  2. Natrolite zeolite: A natural and reusable catalyst for one-pot synthesis of α-aminophosphonates under solvent-free conditions

    Directory of Open Access Journals (Sweden)

    Siavash Bahari

    2017-02-01

    Full Text Available α-Aminophosphonates are synthesized efficiently by one-pot reaction of aldehydes or ketones, amines, trialkyl phosphites in the presence of Natrolite zeolite as a natural catalyst under solvent-free conditions. Furthermore, the catalyst can be reused several times without any significant loss of catalytic activity.

  3. 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

  4. 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.

  5. 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)

  6. Proton Resonance Lines of Water in Heulandite, Mordenite and Clinoptilolite

    International Nuclear Information System (INIS)

    Cruz Inclan, C.; Diaz Quintanilla, D.; Diaz Ruano, A.

    1986-01-01

    It is reported for the first time the proton magnetic resonance spectra of the clinoptilolite and mordenite between 220 K and 440 K. In mordenite it was observed that all water molecules have so an intensive diffusive movement, that they are completely delocalized. In clinoptilolite below 390 K, only a part of the water molecules are completely delocalized. Over 390 K all water molecules become delocalized. This particular behavior of the water molecules in clinoptilolite and mordenite is confronted with those structural models proposed by D.W. Breck. The concept of non-localized quantum state is introduced in order to explain the difference observed with the structural models. (author)

  7. Chemical variability of zeolites at a potential nuclear waste repository, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Broxton, D.E.

    1985-01-01

    The compositions of clinoptilolites and their host tuffs have been examined by electron microprobe and x-ray fluorescence, respectively, to determine their variability at a potential nuclear waste repository, Yucca Mountain, Nevada. Because of their sorptive properties, these zeolites could provide important geologic barriers to radionuclide migration. Variations in clinoptilolite composition can strongly affect the mineral's thermal and ion-exchange properties, thus influencing its behavior in the repository environment. Clinoptilolites and heulandites closest to the proposed repository have calcium-rich compositions (60 to 90 mol. % Ca) and silica-to-aluminum ratios that concentrate between 4.0 and 4.6. In contrast, clinoptilolites and their host tuffs deeper in the volcanic sequence have highly variable compositions that vary vertically and laterally. Deeper-occurring clinoptilolites in the eastern part of Yucca Mountain are characterized by calcic-potassic compositions and tend to become more calcium-rich with depth. Clinoptilolites at equivalent stratigraphic levels on the western side of Yucca Mountain have sodic-potassic compositions and tend to become more sodium-rich with depth. Despite their differences in exchangeable cation compositions these two deeper-occurring compositional suites have similar silica-to-aluminum ratios, concentrating between 4.4 and 5.0. The chemical variability of clinoptilolites and their host tuffs at Yucca Mountain suggest that their physical and chemical properties will also vary. Compositionally-dependent clinoptilolite properties important for repository performance assessment include expansion/contraction behavior, hydration/dehydration behavior, and ion-exchange properties

  8. 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.

  9. 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.

  10. Effectiveness of inorganic membrane mixture of natural zeolite and portland white cement in purifying of peat water based on turbidity parameter

    Science.gov (United States)

    Elfiana; Fuadi, A.; Diana, S.

    2018-04-01

    Peat water is water surface that brownish red colour caused by the contained constituents. Solving the peat watercolor problem requires special attention considering the quantity of peat water and suitable to be used to meet the daily needs. This study aims to know the inorganic membrane capability of mix nature zeolite and white Portland cement to purifying the peat water based on turbidity parameter. The study was conducted by varying the composition of nature zeolite (Za) and white Portland cement (Sp) in the ratio of Za: Sp is (25%:75%; 50%:50%; 75%:25%) with zeolite condition activated using HCl 2M and nonactivated zeolite treatments. The result of the characteristic test on membrane morphology using SEM (Scanning Electron Microscope) showed that the pore surface size of the membrane is 2 μm that could classified in microfiltration membrane an organic type. The characteristic test showed also resulted in the density of 0.77 to 0.86 gr/cm3, porosity 26.22% to 35.93%, and permeability 2736.19 to 8428.15. While the water retention capacity is in range of 30.64% to 46.46%, The result of inorganic membrane application on peat water showed turbidity of peat water decreased 94.17%, from 10.3 NTU to 0.6 NTU.

  11. AFCF and clinoptilolite use in reduction of (137)Cs deposition in several days' contaminated broiler chicks.

    Science.gov (United States)

    Mitrovic, B; Vitorovic, G; Vitorovic, D; Dakovic, A; Stojanovic, M

    2007-01-01

    The objective of this study was to investigate the binding efficiency of AFCF and clinoptilolite, mixed to the feed and administered orally using gastric tube to chronically (137)Cs alimentary contaminated broiler chicks. Seventy-five male Hybro broiler chicks, between 35 and 47 days of age were divided into five groups (15 birds per group) reared in cages (five birds in a cage) and fed a standard diet. Every day during 13 days of the experimental period all chicks received orally 1 ml CsCl water solution with activity of 1310 Bq ml(-1)(137)Cs (gastric tube). Group 1 was the control group and received no binders. The experimental groups received the binders. Group 2 received 0.2 g of AFCF in the form of water solution (gastric tube); group 3 received 0.2% AFCF in the feed; group 4 received 2g clinoptilolite in the form of water suspension (gastric tube) and group 5 received 2% clinoptilolite in the feed. Five chicks from each group were sacrificed on days 4, 10 and 13 of the experimental period. Using gamma spectrometric methods specific activity of (137)Cs was determined in the samples of breast meat, liver and gizzard. The results obtained showed that administering binders to the chronically contaminated broiler chicks significantly (pmeat, liver and gizzard. Decreasing deposition of (137)Cs in breast meat and internal organs increased with time of contamination and binders' administration. With AFCF as a cesium binder, on day 13 of measuring the (137)Cs activity in breast meat was 80-83% lower than that in the control group, 89% in liver and 83-84% in gizzard. Natural clinoptilolite demonstrated lower binding efficiency. On day 13 of measuring the (137)Cs activity in breast meat was 53-69% lower than that in the control group, 67-60% in liver and 59-71% in gizzard.

  12. AFCF and clinoptilolite use in reduction of 137Cs deposition in several days' contaminated broiler chicks

    International Nuclear Information System (INIS)

    Mitrovic, B.; Vitorovic, G.; Vitorovic, D.; Dakovic, A.; Stojanovic, M.

    2007-01-01

    The objective of this study was to investigate the binding efficiency of AFCF and clinoptilolite, mixed to the feed and administered orally using gastric tube to chronically 137 Cs alimentary contaminated broiler chicks. Seventy-five male Hybro broiler chicks, between 35 and 47 days of age were divided into five groups (15 birds per group) reared in cages (five birds in a cage) and fed a standard diet. Every day during 13 days of the experimental period all chicks received orally 1 ml CsCl water solution with activity of 1310 Bq ml -1 137 Cs (gastric tube). Group 1 was the control group and received no binders. The experimental groups received the binders. Group 2 received 0.2 g of AFCF in the form of water solution (gastric tube); group 3 received 0.2% AFCF in the feed; group 4 received 2 g clinoptilolite in the form of water suspension (gastric tube) and group 5 received 2% clinoptilolite in the feed. Five chicks from each group were sacrificed on days 4, 10 and 13 of the experimental period. Using gamma spectrometric methods specific activity of 137 Cs was determined in the samples of breast meat, liver and gizzard. The results obtained showed that administering binders to the chronically contaminated broiler chicks significantly (p 137 Cs transfer and deposition in breast meat, liver and gizzard. Decreasing deposition of 137 Cs in breast meat and internal organs increased with time of contamination and binders' administration. With AFCF as a cesium binder, on day 13 of measuring the 137 Cs activity in breast meat was 80-83% lower than that in the control group, 89% in liver and 83-84% in gizzard. Natural clinoptilolite demonstrated lower binding efficiency. On day 13 of measuring the 137 Cs activity in breast meat was 53-69% lower than that in the control group, 67-60% in liver and 59-71% in gizzard

  13. 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.

  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. 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.

  16. Local Environment and Nature of Cu Active Sites in Zeolite-Based Catalysts for the Selective Catalytic Reduction of NOx

    NARCIS (Netherlands)

    Deka, U.|info:eu-repo/dai/nl/325811202; Lezcano-Gonzalez, I.; Weckhuysen, B.M.|info:eu-repo/dai/nl/285484397; Beale, A.M.|info:eu-repo/dai/nl/325802068

    2013-01-01

    Cu-exchanged zeolites have demonstrated widespread use as catalyst materials in the abatement of NOx, especially from mobile sources. Recent studies focusing on Cu-exchanged zeolites with the CHA structure have demonstrated them to be excellent catalysts in the ammonia-assisted selective catalytic

  17. Co-remediation of the lead-polluted garden soil by exogenous natural zeolite and humic acids.

    Science.gov (United States)

    Shi, Wei-yu; Shao, Hong-bo; Li, Hua; Shao, Ming-an; Du, Sheng

    2009-08-15

    The current study reported the co-remediation effect on the lead-polluted garden soil by zeolite and humic acids (HA), which was from comparing with the remediation of single zeolite in term of the lead fraction of sequential extraction in the soil and the distribution of lead in different parts of rape. Mixed treatment (zeolite and HA) and single treatment (zeolite) were, respectively, applied to the artificially polluted garden soil to examine the difference of their remediation effects in pot experiment. Results indicated that the co-remediation led to significantly greater (plead concentration in plants than by singly adding to zeolite. The co-application of zeolite and HA reduced the available fraction of lead compounds, but slightly increased (plead compounds in the garden soil, compared with the application of single zeolite, especially in the severe lead-polluted soil (> or =1000 mg kg(-1)). This method might be an efficient way to remediate the lead-polluted soils on a large scale, although zeolite is a kind of hazardous material.

  18. 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.

  19. Natural sorptive barriers in Yucca Mountain, Nevada, for long-term isolation of high-level waste

    International Nuclear Information System (INIS)

    Bish, D.L.; Vaniman, D.T.; Rundberg, R.S.; Wolfsberg, K.; Daniels, W.R.; Broxton, D.E.

    1984-01-01

    There are several sorptive phases occurring naturally in the silicic tuffs at Yucca Mountain, Nevada, that can aid in the long-term isolation of high-level wastes. These phases include hydrated volcanic glasses, smectites and zeolites. Los Alamos has a continuing programme to investigate the mineralogy and stratigraphy of the tuffs at Yucca Mountain. In addition, extensive data have been obtained on the sorptive behaviour of technetium, strontium, caesium, barium, cerium, europium, uranium, neptunium, plutonium and americium on the minerals in tuffs. Sorption of elements by ion-exchange processes is high in tuffs containing smectite and the zeolites clinoptilolite-heulandite and mordenite. Moreover, sorption correlates with abundances of these minerals. Sorption is not as high for the zeolite analcime and for volcanic glass. Elements that may not sorb by ion exchange, e.g. plutonium, also tend to be sorbed when the zeolite abundance is high, but the correlations are less clearly defined. Because of the correlation between sorptive capacity and mineralogy, an accurate knowledge of mineral distribution and stratigraphy is essential. The distribution of hydrated glasses is stratigraphically controlled, and the glasses occur in narrow unaltered horizons as vitrophyres and as vitric tuff. Although glasses are of minor importance as sorptive phases, they are very reactive and can alter to other minerals if heated in the presence of water. Smectite clays are reversibly expandable and are widespread in tuffs, but their beneficial properties can be modified by prolonged exposure to elevated temperatures. The zeolites clinoptilolite-heulandite and mordenite occur in high concentrations in silicic tuffs, mostly as secondary alterations of non-welded and poorly welded tuffs; their distribution is therefore stratigraphically controlled

  20. 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)

  1. 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)

  2. 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

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

    Science.gov (United States)

    2012-01-01

    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 zeolite supplementation tended to/or has no significant effects on total egg, eggshell, yolk and albumen weights. It was found also that zeolite mainly increases level of polyunsaturated fatty acids in egg. 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. PMID:22676421

  4. 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)

  5. 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)

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

    KAUST Repository

    Thompson, Joshua A.; Vaughn, Justin T.; Brunelli, Nicholas A.; Koros, William J.; Jones, Christopher W.; Nair, Sankar

    2014-01-01

    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

  7. 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%.

  8. 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.

  9. 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

  10. 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

  11. Anaerobic digestion of swine manure under natural zeolite addition: VFA evolution, cation variation, and related microbial diversity.

    Science.gov (United States)

    Lin, Lin; Wan, Chunli; Liu, Xiang; Lei, Zhongfang; Lee, Duu-Jong; Zhang, Yi; Tay, Joo Hwa; Zhang, Zhenya

    2013-12-01

    Batch experiments were carried out on anaerobic digestion of swine manure under 10 % of total solids and 60 g/L of zeolite addition at 35 °C. Four distinctive volatile fatty acid (VFAs) evolution stages were observed during the anaerobic process, i.e., VFA accumulation, acetic acid (HAc) and butyric acid (HBu) utilization, propionic acid (HPr) and valeric acid (HVa) degradation, and VFA depletion. Large decreases in HAc/HBu and HPr/HVa occurred respectively at the first and second biogas peaks. Biogas yield increased by 20 % after zeolite addition, about 356 mL/g VSadded with accelerated soluble chemical oxygen demand degradation and VFA (especially HPr and HBu) consumption in addition to a shortened lag phase between the two biogas peaks. Compared with Ca(2+) and Mg(2+) (100-300 mg/L) released from zeolite, simultaneous K(+) and NH4 (+) (580-600 mg/L) adsorptions onto zeolite particles contributed more to the enhanced biogasification, resulting in alleviated inhibition effects of ammonium on acidogenesis and methanogenesis, respectively. All the identified anaerobes could be grouped into Bacteroidetes and Firmicutes, and zeolite addition had no significant influence on the microbial biodiversity in this study.

  12. 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.

  13. Conversion of radwaste-loaded zeolites into a borosilicate glass to improve their properties for final disposal (preliminary results)

    International Nuclear Information System (INIS)

    Kazemian, H.; Ghannadi Maraghe, M.; Mallah, M.H.; Firooz Zare, M.; Kooshkestani, R.; Naghavi, S.Sh.

    2002-01-01

    Research was undertaken to fix radioisotopes from simulated nuclear waste streams into durable and stable borosilicate glass matrices based on the conversion of different type of zeolites. It was found that the selectivity of Iranian clinoptilolite and the relevant synthetic zeolite toward cesium and strontium were quite good whereas the leach resistance of the loaded zeolite was relatively poor. To improve the leach resistance of the used zeolites, conversion of the spent exchangers into borosilicate glass was investigated. Results obtained in the non active bench scale tests phase were promising. It is concluded that spent zeolites loaded with radioactive materials can be converted into a durable, high leach resistant borosilicate glass, a proper matrix for final disposal of nuclear waste. (author)

  14. 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)

  15. Zeolites with continuously tuneable porosity

    OpenAIRE

    Wheatley, Paul S; Chlubná-Eliášová, Pavla; Greer, Heather; Zhou, Wuzong; Seymour, Valerie R; Dawson, Daniel M; Ashbrook, Sharon E; Pinar, Ana B; McCusker, Lynne B; Opanasenko, Maksym; Cejka, Jiří; Morris, Russell E

    2014-01-01

    Czech Science Foundation. Grant Number: P106/12/G015 Zeolites are important materials whose utility in industry depends on the nature of their porous structure. Control over microporosity is therefore a vitally important target. Unfortunately, traditional methods for controlling porosity, in particular the use of organic structure-directing agents, are relatively coarse and provide almost no opportunity to tune the porosity as required. Here we show how zeolites with a continuously tuneabl...

  16. 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

  17. Chemical reactivity of cation-exchanged zeolites

    OpenAIRE

    Pidko, E.A.

    2008-01-01

    Zeolites modified with metal cations have been extensively studied during the last two decades because of their wide application in different technologically important fields such as catalysis, adsorption and gas separation. Contrary to the well-understood mechanisms of chemical reactions catalyzed by Brønsted acid sites in the hydrogen forms of zeolites, the nature of chemical reactivity, and related, the structure of the metal-containing ions in cation-exchanged zeolites remains the subject...

  18. Zeolite function studied by neutron diffraction

    International Nuclear Information System (INIS)

    Newsam, J.M.

    1988-01-01

    Some recent figures relating to industrial uses of zeolites are summarized. Recent advances in the application of neutron diffraction to zeolite science are overviewed, with particular emphasis on powder diffraction (PND) results. Single crystal neutron diffraction studies of some 17 hydrated natural and synthetic zeolites have now appeared and they provide a consistent picture of zeolite-water interactions. Complete PND studies of hydrated synthetic ABW- and SOD-framework zeolites have also been reported. Other PND studies have explored the structural consequences of non-framework cation exchange, of framework modification by dealumination, and of framework cation substitution. Relatively simple zeolite-hydrocarbon sorbate complexes that have been studied include benzene in zeolite Y, and benzene and pyridine in zeolite L. Areas that are well poised for further development include further extensions to lower symmetry systems, the use of PND data for zeolite structure solution, studies at elevated temperatures and pressures, and further studies of zeolite sorbate complexes. (author) 68 refs., 7 figs

  19. 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.

  20. High performance nano-titania photocatalytic paper composite. Part I: Experimental design study for TiO2 composite sheet using a natural zeolite microparticle system and its photocatalytic property

    International Nuclear Information System (INIS)

    Ko, Seonghyuk; Pekarovic, Jan; Fleming, Paul D.; Ari-Gur, Pnina

    2010-01-01

    Nanosized titanium dioxide (TiO 2 ) photocatalytic papers were successfully prepared using a natural zeolite microparticle retention aid in papermaking. Applying a factorial experimental design, natural zeolite has been demonstrated to be the most significant and interactive factor for increasing the TiO 2 retention rate in paper stock. The photocatalysis of as-prepared sheets was evaluated with toluene as one of the representative volatile organic compounds (VOCs). Under UV irradiation, it was shown to be effective in removing gaseous toluene by photodecomposition, assisted by adsorption. It was revealed that natural zeolite plays an important role in both increasing retention rate of TiO 2 nanoparticles and enhancing photocatalytic efficiency of the paper. The photocatalytic paper can be potentially applied for environmental purification.

  1. Characterization of natural adsorbent material for heavy metal removal in a petrochemical site contamination

    Directory of Open Access Journals (Sweden)

    Bianchi F.

    2013-04-01

    Full Text Available Despite of over 25 years of intensive technological efforts, sub-surface environment cleanup still remains a challenge, especially in case of highly contaminated sites. In this context, ion exchanger technologies could provide simple and effective solutions for heavy metal removal in water treatment. The challenge is finding exchanger able to operate in extreme natural environments or in situations involving natural interfering species such as inorganic ions. In this paper we exam the use of natural zeolites as versatile exchanger for environmental protection of coastal refinery's groundwater against pollution of Ni, Cd, Pb. The influence of particle diameter on clinoptilolite performances toward heavy metal removal is studied. Also, we evaluate the exchanger activities in condition of high ionic strength, commonly present in groundwater located under coastal petrol industries. The obtained results confirmed that ion exchangers could provide an effective solutions for remediation in complex environmental conditions.

  2. New developments in zeolite science and technology

    International Nuclear Information System (INIS)

    Murakami, Y.

    1986-01-01

    The contributions in this volume introduce numerous new results and concepts. MAS-NMR has become a powerful tool in the structural analysis of zeolite, metallosilicate and aluminophosphate, enabling definition at the atomic level of the silicon and aluminum forming the zeolite framework. Detailed knowledge on the structure of natural zeolite has increased. Regarding synthesis, studies on the preparation of various metallosilicates, the role of various organic compounds at templates and the kinetics of crystallization and crystal growth are presented. Developments in zeolite catalysts focus not only on the solid-acid catalysts and the shape selective catalysts but on the bifunctional type catalysts as well. Catalyses by metallosilicates or silicoaluminophosphates are reported. Attempts to improve the catalytic performance by modification are presented. Effort is also being devoted to the analysis of adsorption state and diffusion in zeolites. Zeolite deposits of economic value are reported from several countries. (Auth.)

  3. 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.

  4. Zeolites in poultry and swine production

    Directory of Open Access Journals (Sweden)

    Aline Félix Schneider

    Full Text Available ABSTRACT: Zeolites are minerals that have intriguing properties such as water absorption, ion adsorption and cation exchange capacity. There are approximately 80 species of natural zeolites recognized and hundreds of artificial zeolites, which have been researched in several fields. Due to their chemical characteristics, zeolites have great potential for use in animal production, especially in poultry and swine farms, as food additives, litter amendment and treatment of residues, with direct and indirect effects on performance, yield and quality of carcass, ambience of farm sheds and reduction of environmental pollution.

  5. 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

  6. Basic deposits of zeolites of the Republic of Tajikistan

    International Nuclear Information System (INIS)

    Normatov, I.Sh.; Mirsaidov, U.M.

    2003-01-01

    Natural zeolites increasingly using in the different fields of human economical activity. As a result of investigations of last years was determined that zeolites are the wide-spread rock forming minerals. In the Republic of Tajikistan zeolites was found out an the north of the Republic

  7. The bioaccumulation of heavy metals in barley (Hordeum vulgare L cultivated on fly ash dump mixed with compost and natural zeolite materials

    Directory of Open Access Journals (Sweden)

    Smaranda Mâșu

    2012-10-01

    Full Text Available The physic-chemical characteristics of the upper layers of fly ash dumps are very important when phytostabilizationplant selection is carried out. Plants with topsoil well developed roots, like cereals are used to stabilize fly ash dumpsin order to eliminate the deflation, erosion, etc. These plant species could be used in thephytostabilization/phytoextraction variant taking into account their metal hyper accumulation capacity, and also inphytostabilization variant by adequate topsoil treatments when a decrease mobility of metals from soil to plants isachieved and thus a less toxic crop is obtained. This study presents a comparative analysis of the metalbioaccumulation degree in plant tissues (grain and straw of barley cultivated on fly ash variants treated withdifferent quantities of compost in the absence/presence of natural zeolite materials, indigenous volcanic tuff. Theaddition of plant debris and sewage sludge compost mixed with natural zeolite materials has lowered thebioaccumulation of Cr with 49%, of Cu with 29%, Fe with more than 77.5%, in grains and straw when compared tountreated fly ash. Barley plants does not allow for Pb and Ni transfer from the fly ash in the aerial part of tissue.

  8. Potentiated clinoptilolite: artificially enhanced aluminosilicate reduces symptoms associated with endoscopically negative gastroesophageal reflux disease and nonsteroidal anti-inflammatory drug induced gastritis

    Directory of Open Access Journals (Sweden)

    Potgieter W

    2014-07-01

    clinoptilolite. Treatment with the potentiated clinoptilolite resulted in significant prevention (P≤0.05 of mucosal erosion severity as graded by the gastroenterologist.Conclusion: Absorbatox is a nonabsorbable aluminosilicate with potential gastroprotective benefits as it protected against ENGORD symptoms and NSAID-induced gastric events. The exact mechanism of action is not clear but may be due to its binding to hydrogen ions and biologically active amines and nitrates.Keywords: cation exchanger, gastro-protective agent, endoscopy, zeolite

  9. 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

  10. Equilibrium modeling of the formation of zeolites in fractures at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Chipera, S.J.; Bish, D.L.; Carlos, B.A.

    1993-01-01

    Yucca Mountain, in southern Nevada, is currently being investigated to determine its suitability to host the first US high-level nuclear waste repository. One of the reasons that Yucca Mountain was chosen for study is the presence of thick sequences of zeolite-rich horizons. In as much as fractures may serve as potential pathways for aqueous transport, the minerals that line fractures are of particular interest. Zeolites are common in fractures at Yucca Mountain and consist mainly of clinoptilolite/heulandite and mordenite although sporadic occurrences of chabazite, erionite, phillipsite, and stellrite have been identified using X-ray powder diffraction. To understand better the conditions under which the observed zeolite species were formed, thermodynamic data were estimated and calculations of log a((K + ) 2 /Ca ++ ) versus log a((Na + ) 2 /Ca ++ ) were conducted at various temperatures and silica activities. Using present-day Yucca Mountain water chemistries as a lower constraint on silica activity, clinoptilolite/heulandite and mordenite are still the zeolite species that would form under present conditions

  11. 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.

  12. Serum Protein Electrophoretic Pattern in Neonatal Calves Treated with Clinoptilolite

    Directory of Open Access Journals (Sweden)

    Simona Marc

    2018-05-01

    Full Text Available The objective of our study was to determine the effects of clinoptilolite supplemented in colostrum on the blood serum protein electrophoretic pattern of new-born calves. Methods: Romanian Black and White new-born calves involved in the study were divided into 3 groups: the control group (C that received colostrum without clinoptilolite, and experimental groups I (E1 and II (E2 that received colostrum supplemented with 0.5% and 2% clinoptilolite, respectively. The concentration of total protein and protein fractions (albumin, α1-globulin, α2-globulin, β-globulin and γ-globulin were analyzed by electrophoresis on cellulose acetate. Results: At hour 30 after birth, concentrations of γ-globulins, β-globulin and total protein in E1 group of calves were higher than in control group by 42.11% (p < 0.05, 28.48% (p > 0.05 and 18.52% (p > 0.05, respectively, and were higher, but not significantly, in group E2 compared to the control group. This was in accordance with a significant lower albumin/globulin ratio in groups E1 and E2 (29.35%, p < 0.05 and 35.87%, p < 0.05, respectively than in control group at 30 h postpartum, which indicates an obvious increase of the globulins fraction in experimental groups. The conclusion: Clinoptilolite was effective in improving passive transfer in new-born calves, but it was more effective if added in colostrum with a dose of 0.5% than with a dose of 2%.

  13. Adsorption of aqueous Zn(II) species on synthetic zeolites

    International Nuclear Information System (INIS)

    Badillo-Almaraz, Veronica; Trocellier, Patrick; Davila-Rangel, Ignacio

    2003-01-01

    To supply a good quality drinkable water tends to become a strategic task in both developed and under development countries in the world due to the number of potential contamination sources. One of the major problems is derived from the presence of heavy toxic metals like zinc or lead resulting from industrial activities. Zeolites are known as very efficient mineral substrates for fixing aqueous ionic species through their wide range of channels present in the crystalline structure and due to their strong surface reactivity. MicroPIXE coupled with microRBS (3.05 MeV 4 He + ions) have been used to quantify the incorporation of zinc within two commercial zeolites containing alkali elements (zeolite X and clinoptilolite) in the concentration range of: 0.0002-0.05 M at neutral pH. At the beginning of the interaction between zeolite and Zn(II) solution, the adsorption process exhibits a direct proportionality between the content of zinc fixed on the mineral substrate and the aqueous concentration up to 0.01 M. Beyond this point a saturation effect seems to occur, indicating the strong decrease of available adsorption sites. Sodium or potassium ions are probably exchanged with Zn(II) ions during this process. The compared behaviour of the two zeolites is then discussed in terms of kinetic effects based on ionic radius values. A co-adsorption test carried on with a 50-50% Zn(II) 0.001 M-Pb(II) 0.001 M solution shows that lead does not occupy the same sites as zinc because the content of zinc fixed on the zeolite sample exactly corresponds to the result obtained with a pure 0.001 M Zn(II) solution. All these data clearly showed that zeolite surface reactivity is greatly influenced by the mineral cage-like structure and particularly the presence of pockets, spaces and channels

  14. 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

  15. 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.

  16. 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.

  17. 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)

  18. 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)

  19. 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...... crystals, nanosized zeolite crystals, and supported zeolite crystals. For the pure zeolite materials in the first two categories, the additional meso- or macroporosity can be classified as being either intracrystalline or intercrystalline, whereas for supported zeolite materials, the additional porosity...... 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...

  20. 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

  1. Zeolites with Continuously Tuneable Porosity**

    Science.gov (United States)

    Wheatley, Paul S; Chlubná-Eliášová, Pavla; Greer, Heather; Zhou, Wuzong; Seymour, Valerie R; Dawson, Daniel M; Ashbrook, Sharon E; Pinar, Ana B; McCusker, Lynne B; Opanasenko, Maksym; Čejka, Jiří; Morris, Russell E

    2014-01-01

    Zeolites are important materials whose utility in industry depends on the nature of their porous structure. Control over microporosity is therefore a vitally important target. Unfortunately, traditional methods for controlling porosity, in particular the use of organic structure-directing agents, are relatively coarse and provide almost no opportunity to tune the porosity as required. Here we show how zeolites with a continuously tuneable surface area and micropore volume over a wide range can be prepared. This means that a particular surface area or micropore volume can be precisely tuned. The range of porosity we can target covers the whole range of useful zeolite porosity: from small pores consisting of 8-rings all the way to extra-large pores consisting of 14-rings. PMID:25284344

  2. Investigation of mircroorganisms colonising activated zeolites during anaerobic biogas production from grass silage.

    Science.gov (United States)

    Weiss, S; Zankel, A; Lebuhn, M; Petrak, S; Somitsch, W; Guebitz, G M

    2011-03-01

    The colonisation of activated zeolites (i.e. clinoptilolites) as carriers for microorganisms involved in the biogas process was investigated. Zeolite particle sizes of 1.0-2.5mm were introduced to anaerobic laboratory batch-cultures and to continuously operated bioreactors during biogas production from grass silage. Incubation over 5-84 days led to the colonisation of zeolite surfaces in small batch-cultures (500 ml) and even in larger scaled and flow-through disturbed bioreactors (28 l). Morphological insights were obtained by using scanning electron microscopy (SEM). Single strand conformation polymorphism (SSCP) analysis based on amplification of bacterial and archaeal 16S rRNA fragments demonstrated structurally distinct populations preferring zeolite as operational environment. via sequence analysis conspicuous bands from SSCP patterns were identified. Populations immobilised on zeolite (e.g. Ruminofilibacter xylanolyticum) showed pronounced hydrolytic enzyme activity (xylanase) shortly after re-incubation in sterilised sludge on model substrate. In addition, the presence of methanogenic archaea on zeolite particles was demonstrated. Copyright © 2010 Elsevier Ltd. All rights reserved.

  3. 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.

  4. Design and fabrication of zeolite macro- and micromembranes

    Science.gov (United States)

    Chau, Lik Hang Joseph

    2001-07-01

    The chemical nature of the support surface influences zeolite nucleation, crystal growth and elm adhesion. It had been demonstrated that chemical modification of support surface can significantly alter the zeolite film and has a good potential for large-scale applications for zeolite membrane production. The incorporation of titanium and vanadium metal ions into the structural framework of MFI zeolite imparts the material with catalytic properties. The effects of silica and metal (i.e., Ti and V) content, template concentration and temperature on the zeolite membrane growth and morphology were investigated. Single-gas permeation experiments were conducted for noble gases (He and Ar), inorganic gases (H2, N2, SF6) and hydrocarbons (methane, n-C4, i-C4) to determine the separation performance of these membranes. Using a new fabrication method based on microelectronic fabrication and zeolite thin film technologies, complex microchannel geometry and network (supported zeolite films. The zeolite micropatterns were stable even after repeated thermal cycling between 303 K and 873 K for prolonged periods of time. This work also demonstrates that zeolites (i.e., Sil-1, ZSM-5 and TS-1) can be employed as catalyst, membrane or structural materials in miniature chemical devices. Traditional semiconductor fabrication technology was employed in micromachining the device architecture. Four strategies for the manufacture of zeolite catalytic microreactors were discussed: zeolite powder coating, uniform zeolite film growth, localized zeolite growth, and etching of zeolite-silicon composite film growth inhibitors. Silicalite-1 was also prepared as free-standing membrane for zeolite membrane microseparators.

  5. 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.

  6. Zeolite food supplementation reduces abundance of enterobacteria.

    Science.gov (United States)

    Prasai, Tanka P; Walsh, Kerry B; Bhattarai, Surya P; Midmore, David J; Van, Thi T H; Moore, Robert J; Stanley, Dragana

    2017-01-01

    According to the World Health Organisation, antibiotics are rapidly losing potency in every country of the world. Poultry are currently perceived as a major source of pathogens and antimicrobial resistance. There is an urgent need for new and natural ways to control pathogens in poultry and humans alike. Porous, cation rich, aluminosilicate minerals, zeolites can be used as a feed additive in poultry rations, demonstrating multiple productivity benefits. Next generation sequencing of the 16S rRNA marker gene was used to phylogenetically characterize the fecal microbiota and thus investigate the ability and dose dependency of zeolite in terms of anti-pathogenic effects. A natural zeolite was used as a feed additive in laying hens at 1, 2, and 4% w/w for a 23 week period. At the end of this period cloacal swabs were collected to sample faecal microbial communities. A significant reduction in carriage of bacteria within the phylum Proteobacteria, especially in members of the pathogen-rich family Enterobacteriaceae, was noted across all three concentrations of zeolite. Zeolite supplementation of feed resulted in a reduction in the carriage of a number of poultry pathogens without disturbing beneficial bacteria. This effect was, in some phylotypes, correlated with the zeolite concentration. This result is relevant to zeolite feeding in other animal production systems, and for human pathogenesis. Copyright © 2016 Elsevier GmbH. All rights reserved.

  7. Effects of Clinoptilolite on Copper Accumulation of Oreochromis niloticus

    Directory of Open Access Journals (Sweden)

    Nuray Çiftçi

    2018-05-01

    Full Text Available The copper accumulation in liver and gill tissues of Oreochromis niloticus, exposed to 2 ppm Cu and 1g/L clinoptilolite singly and to the same concentrations of their mixture over 24, 48, 72 and 96 hours was studied. ICP-AES spectrophotometer techniques were applied in determining tissue copper levels. Statistical evaluation of the experimental data was carried out by Student Newman Keul’s procedure. No mortality was observed during the experiments. Copper accumulation was lower in metal-clinoptilolite mixture group than metal singly group in gill tissue while no accumulation in both experimental groups in liver tissue (P<0.05. In addition, the copper level in the liver was lower in all experimental groups than in the control (P<0.05. Low Cu accumulation in gill tissue exposed in mixture groups can be explained by copper adsorption with chelating agent. The decrease of Cu reserves in the liver can be expressed by increase of copper-containing enzyme and protein synthesis.

  8. Effect of natural Bayah zeolite particle size reduction to physico-chemical properties and absortion against potassium permanganate (KMnO4)

    Science.gov (United States)

    Widayanti, Siti Mariana; Syamsu, Khaswar; Warsiki, Endang; Yuliani, Sri

    2016-02-01

    Recently, researches on nanotechnology have been developed very rapid, as well as the utilization of nano-zeolites. Nano-sized material has several advantages which are expanding absorptive surfaces so it will enhance the material absorption and shorten the absorption time. Zeolite as a KMnO4 binder, has been widely recognized for its ability to extend the shelf life of vegetables and fruits. This study was conducted to determine zeolites physico-chemical characters from different particle size and the effect on KMnO4 absorption. Potassium permanganate (KMnO4) is a strong oxidizer for reducing the quantity of ethylene in storage process of fresh horticultural products. The treatment consisted of (1) different length of milling time (10, 20, 30, 40, and 60 minutes) and (2) the duration of chemical activation with 1 N KOH solution. Physical and chemical characters of zeolite were analyzed using BET, PSA, XRD and SEM. The research design was randomized design. The result implied that milling time was significantly affecting the zeolite particle size, material surface area, and the size of pore diameter and volume. Milling treatment for 40 minutes produced higher zeolite surface area and pore volume than other treatments. While the duration of chemical activation using 1 N KOH solution gives different effect on zeolite absorption to KMnO4 solution. Milling time for 60 minutes and activated for 48 hours has higher initial adsorption than other treatments.

  9. AFCF and clinoptilolite use in reduction of {sup 137}Cs deposition in several days' contaminated broiler chicks

    Energy Technology Data Exchange (ETDEWEB)

    Mitrovic, B. [Faculty of Veterinary Medicine, Department of Radiology, 18 Bulevar JA, 11 000 Belgrade (Serbia)]. E-mail: radijacija@vet.bg.ac.yu; Vitorovic, G. [Faculty of Veterinary Medicine, Department of Radiology, 18 Bulevar JA, 11 000 Belgrade (Serbia); Vitorovic, D. [Faculty of Agriculture, Department of Animal Science, 6 Nemanjina, 11 080 Belgrade (Serbia); Dakovic, A. [Institute for Technology of Nuclear and Other Raw Materials, 86 Franche D' Epere, 11 000 Belgrade (Serbia); Stojanovic, M. [Institute for Technology of Nuclear and Other Raw Materials, 86 Franche D' Epere, 11 000 Belgrade (Serbia)

    2007-06-15

    The objective of this study was to investigate the binding efficiency of AFCF and clinoptilolite, mixed to the feed and administered orally using gastric tube to chronically {sup 137}Cs alimentary contaminated broiler chicks. Seventy-five male Hybro broiler chicks, between 35 and 47 days of age were divided into five groups (15 birds per group) reared in cages (five birds in a cage) and fed a standard diet. Every day during 13 days of the experimental period all chicks received orally 1 ml CsCl water solution with activity of 1310 Bq ml{sup -1} {sup 137}Cs (gastric tube). Group 1 was the control group and received no binders. The experimental groups received the binders. Group 2 received 0.2 g of AFCF in the form of water solution (gastric tube); group 3 received 0.2% AFCF in the feed; group 4 received 2 g clinoptilolite in the form of water suspension (gastric tube) and group 5 received 2% clinoptilolite in the feed. Five chicks from each group were sacrificed on days 4, 10 and 13 of the experimental period. Using gamma spectrometric methods specific activity of {sup 137}Cs was determined in the samples of breast meat, liver and gizzard. The results obtained showed that administering binders to the chronically contaminated broiler chicks significantly (p < 0.01) reduced {sup 137}Cs transfer and deposition in breast meat, liver and gizzard. Decreasing deposition of {sup 137}Cs in breast meat and internal organs increased with time of contamination and binders' administration. With AFCF as a cesium binder, on day 13 of measuring the {sup 137}Cs activity in breast meat was 80-83% lower than that in the control group, 89% in liver and 83-84% in gizzard. Natural clinoptilolite demonstrated lower binding efficiency. On day 13 of measuring the {sup 137}Cs activity in breast meat was 53-69% lower than that in the control group, 67-60% in liver and 59-71% in gizzard.

  10. 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.

  11. Competitive adsorption of dyes and heavy metals on zeolitic structures.

    Science.gov (United States)

    Hernández-Montoya, V; Pérez-Cruz, M A; Mendoza-Castillo, D I; Moreno-Virgen, M R; Bonilla-Petriciolet, A

    2013-02-15

    The adsorption of Acid blue 25, basic blue 9, basic violet 3, Pb(2+), Ni(2+), Zn(2+) and Cd(2+) ions has been studied in single and dye-metal binary solutions using two mineral materials: Clinoptilolite (CL) and ER (Erionite). These zeolites were characterized by FT-IR spectroscopy; potentiometric titration and nitrogen adsorption isotherms at 77 K to obtain their textural parameters. Results indicated that ER has an acidic character and a high specific surface (401 m(2) g(-1)) in contrast with the zeolite CL (21 m(2) g(-1)). Surprisingly, the removal of dyes was very similar for the two zeolites and they showed a considerable selectivity by the basic dyes in comparison with the acid dyes. In the case of heavy metals, ER was more effective in the adsorption process showing a selectivity of: Pb(2+) > Ni(2+) > Zn(2+) > Cd(2+). In the multicomponent adsorption experiments an antagonistic effect was observed in the removal of basic dyes and heavy metals. Particularly, the adsorbed amount of basic violet 3 decreased more significantly when the heavy metals are presents in contrast with the basic blue 9. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. 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....

  13. Zeolite and swine inoculum effect on poultry manure biomethanation

    Science.gov (United States)

    Kougias, P. G.; Fotidis, I. A.; Zaganas, I. D.; Kotsopoulos, T. A.; Martzopoulos, G. G.

    2013-03-01

    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.

  14. 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)

  15. 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...

  16. Adsorption methods for hydrogen isotope storage on zeolite sieves

    International Nuclear Information System (INIS)

    Cristescu, Ioana; Cristescu, Ion; Vasut, Felicia; Brad, Sebastian; Lazar, Alin

    2001-01-01

    Adsorption molecular sieves and activated carbon were used for hydrogen isotopes. The adsorption process proceeds at liquid nitrogen and liquid hydrogen temperatures. The synthetic zeolites have similar properties as natural zeolites, but they have a regular pore structure and affinity for molecules of different size with defined shapes. Experimental results obtained at liquid nitrogen and liquid hydrogen temperatures evidenced the efficient behavior of the activated carbon and zeolite sieves for hydrogen isotope temporary storage. (authors)

  17. Sorption of uranium by clinoptilolite modified by a some metals hydroxides

    International Nuclear Information System (INIS)

    Plotnikov, V.I.; Medvedeva, Z.V.; Zhabykbaev, G.T.

    2005-01-01

    In the present report the sorption character of uranium (IV) in the static conditions on the thin layer sorbents with application of the clinoptilolite of the Chankan deposit of the Republic of Kazakhstan is shown. A wide circle of metal hydroxides - in both the individual form and in the their mixture - is used. It is shown that the most sorptive capacity against the uranium (IV) has the modified clinoptilolite of MnO 2

  18. 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)

  19. 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.

  20. 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.

  1. Zeolitization of intracaldera sediments and rhyolitic rocks in the 1.25 Ma lake of Valles caldera, New Mexico, USA

    Science.gov (United States)

    Chipera, Steve J.; Goff, Fraser; Goff, Cathy J.; Fittipaldo, Melissa

    2008-12-01

    Quantitative X-ray diffraction analysis of about 80 rhyolite and associated lacustrine rocks has characterized previously unrecognized zeolitic alteration throughout the Valles caldera resurgent dome. The alteration assemblage consists primarily of smectite-clinoptilolite-mordenite-silica, which replaces groundmass and fills voids, especially in the tuffs and lacustrine rocks. Original rock textures are routinely preserved. Mineralization typically extends to depths of only a few tens of meters and resembles shallow "caldera-type zeolitization" as defined by Utada et al. [Utada, M., Shimizu, M., Ito, T., Inoue, A., 1999. Alteration of caldera-forming rocks related to the Sanzugawa volcanotectonic depression, northeast Honshu, Japan — with special reference to "caldera-type zeolitization." Resource Geol. Spec. Issue No. 20, 129-140]. Geology and 40Ar/ 39Ar dates limit the period of extensive zeolite growth to roughly the first 30 kyr after the current caldera formed (ca. 1.25 to 1.22 Ma). Zeolitic alteration was promoted by saturation of shallow rocks with alkaline lake water (a mixture of meteoric waters and degassed hydrothermal fluids) and by high thermal gradients caused by cooling of the underlying magma body and earliest post-caldera rhyolite eruptions. Zeolitic alteration of this type is not found in the later volcanic and lacustrine rocks of the caldera moat (≤ 0.8 Ma) suggesting that later lake waters were cooler and less alkaline. The shallow zeolitic alteration does not have characteristics resembling classic, alkaline lake zeolite deposits (no analcime, erionite, or chabazite) nor does it contain zeolites common in high-temperature hydrothermal systems (laumontite or wairakite). Although aerially extensive, the early zeolitic alteration does not form laterally continuous beds and are consequently, not of economic significance.

  2. Processing of radioactive waste solution with zeolites. I. Thermal transformation of Na, Cs and Sr type zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Kanno, T; Mimura, H; Kitamura, T [Tohoku Univ., Sendai (Japan). Research Inst. of Mineral Dressing and Metallurgy

    1976-08-01

    Thermal transformation of Na, Cs and Sr type zeolites were studied by means of differential thermal analysis (DTA), thermogravimetric analysis (TGA) and X-ray powder diffraction. Synthetic zeolites A, X and Y, synthetic mordenite (Zeolon) and natural mordenite were used in this study. Na type zeolites of A and X recrystallized to Nepheline (NaAlSiO/sub 4/) above 1,000/sup 0/C, but the structures of zeolite Y and mordenite collapsed above about 900/sup 0/C and did not recrystallize until 1,200/sup 0/C. Cs type zeolites of A and X recrystallized to pollucite (CsAlSi/sub 2/O/sub 6/) above 1,000/sup 0/C and Cs type of zeolite Y recrystallized to it above 1,100/sup 0/C, but the structure of mordenite collapsed above 1,000/sup 0/C and did not recrystallize until 1,200/sup 0/C. On Sr type zeolites, zeolite A and X recrystallized to strontium aluminosilicate (SrAl/sub 2/Si/sub 2/O/sub 8/) above 1,100/sup 0/C and zeolite Y recrystallized to it above 1,200/sup 0/C, but the structure of mordenite collapsed above 1,000/sup 0/C. The results described above were supported by microscopic observation and the measurement of density. If this solidifications by calcination of zeolites are further studied, new informations concerning the fixation of Cs and Sr will be obtained.

  3. Electron irradiation of zeolites

    International Nuclear Information System (INIS)

    Wang, S.X.; Wang, L.M.; Ewing, R.C.

    1999-01-01

    Three different zeolites (analcime, natrolite, and zeolite-Y) were irradiated with 200 keV and 400 keV electrons. All zeolites amorphized under a relatively low electron fluence. The transformation from the crystalline-to-amorphous state was continuous and homogeneous. The electron fluences for amorphization of the three zeolites at room temperature were: 7.0 x 10 19 e - /cm 2 (analcime), 1.8 x 10 20 e - /cm 2 (natrolite), and 3.4 x 10 20 e - /cm 2 (zeolite-Y). The different susceptibilities to amorphization are attributed to the different channel sizes in the structures which are the pathways for the release of water molecules and Na + . Natrolite formed bubbles under electron irradiation, even before complete amorphization. Analcime formed bubbles after amorphization. Zeolite-Y did not form bubbles under irradiation. The differences in bubble formation are attributed to the different channel sizes of the three zeolites. The amorphization dose was also measured at different temperatures. An inverse temperature dependence of amorphization dose was observed for all three zeolites: electron dose for amorphization decreased with increasing temperature. This unique temperature effect is attributed to the fact that zeolites are thermally unstable. A semi-empirical model was derived to describe the temperature effect of amorphization in these zeolites

  4. Detergent zeolite filtration plant

    OpenAIRE

    Stanković Mirjana S.; Pezo Lato L.

    2003-01-01

    The IGPC Engineering Department designed basic projects for detergent zeolite filtration plant, using technology developed in the IGPC laboratories. Several projects were completed: technological, machine, electrical, automation. On the basis of these projects, a production plant with a capacity of 75,000 t/y was manufactured, at "Zeolite Mira", Mira (VE), Italy, in 1997, for increasing detergent zeolite production, from 50,000 to 100,000 t/y. The main goal was to increase the detergent zeoli...

  5. 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 ...

  6. Characterization of natural pozzolan-based geopolymeric binders

    KAUST Repository

    Moon, Juhyuk; Bae, Sungchul; Celik, Kemal; Yoon, Seyoon; Kim, Ki-Hyun; Kim, Kang Su; Monteiro, Paulo J.M.

    2014-01-01

    of natural pozzolan for sustainable construction material. It is concluded that the geopolymers have sufficient strength as structural materials and matrices contain C-S-H like crystal as well as zeolites of hydroxysodalite and zeolite Y. Two zeolites

  7. 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)

  8. Human bile sorption by cancrinite-type zeolites

    International Nuclear Information System (INIS)

    Linares, Carlos F.; Colmenares, Maryi; Ocanto, Freddy; Valbuena, Oscar

    2009-01-01

    A nitrated cancrinite-type zeolite was synthesized from zeolite X, NaOH and NaNO 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

  9. 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.)

  10. Acidity in zeolite catalysis

    NARCIS (Netherlands)

    Santen, van R.A.; Gauw, de F.J.M.M.; Corma, A.; Melo, F.; Mendioroz, S.; Fierro, J.L.G.

    2000-01-01

    A review with 21 refs. is provided on our current understanding of the activation of hydrocarbons by protonic zeolites. One has to distinguish the proton affinity of a zeolite, measured in an equil. expt., from proton activation that dets. a kinetic catalytic result. The proton affinity depends on

  11. Zeolite ZSM-57

    International Nuclear Information System (INIS)

    Valyocsik, E.W.; Page, N.M.; Chu, C.T.W.

    1989-01-01

    This patent describes a synthetic porous crystalline zeolite having a molar ratio of XO 2 ; Y 2 O 3 of at least 4. Wherein X represents silicon and/or germanium and Y represents aluminum, boron, chromium, iron and/or gallium. The porous crystalline zeolite having at least the X-ray diffraction lines as set forth in the text

  12. 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,

  13. 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)

  14. 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.

  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. Comparison the efficiency of AFCF and clinoptilolit obtained through single Cs 137 contamination of pheasants

    International Nuclear Information System (INIS)

    Vicentijevic, M.; Mitrovic, R.; Vitorovic, G.

    2009-01-01

    In practice are show effect of comparison efficiency AFCF and clinoptilolite obtained trough single 137 Cs contamination of pheasants. As experimental animals we used pheasants from the species pheasant colchicus. The total number of 2 months old pheasants, was 20. The pheasants were divided into 4 groups with 5 birds each. Every animal was simultaneously given water solution of 137 Cs (750 Bq) and radioprotector AFCF and clinoptilolite in water solution and mixed in pheasant food in the form of pellet. The level of contamination was determined by gamma - spectrometry in light meat, dark meat, liver and gizzard. The results show that the best protection effect was obtained by using AFCF than use radioprotector clinoptilolite. (author) [sr

  17. Methanol conversion to hydrocarbons using modified clinoptilolite catalysts. Investigation of catalyst lifetime and reactivation

    Energy Technology Data Exchange (ETDEWEB)

    Hutchings, G J; Themistocleous, T; Copperthwaite, R G

    1988-10-17

    A study of the deactivation and reactivation of modified clinoptilolite catalysts for methanol conversion to hydrocarbons is reported. Clinoptilolite catalysts, modified by either ammonium ion exchange or hydrochloric acid treatment, exhibit a short useful catalyst lifetime for this reaction (ca. 2-3 h) due to a high rate of coke deposition (3-5.10/sup -3/ g carbon/g catalyst/h). A comparative study of reactivation using oxygen, nitrous oxide and ozone/oxygen as oxidants indicated that nitrous oxide reactivation gives improved catalytic performance when compared to the activity and lifetime of the fresh catalyst. Both oxygen and ozone/oxygen were found to be ineffective for the reactivation of clinoptilolite. Initial studies of in situ on-line reactivation are also described. 3 figs., 15 refs., 4 tabs.

  18. 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

  19. 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

  20. 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)

  1. Pengaruh Kandungan Ca Pada Cao-zeolit Terhadap Kemampuan Adsorpsi Nitrogen

    OpenAIRE

    M Nasikin; Tania Surya Utami; Agustina TP Siahaan

    2002-01-01

    In industry, Ca zeolite is used as nitrogen selective adsorbent with the use of PSA (Pressure Swing Adsorption)/VSA (Vacuum Swing Adsorption) methods. Natural zeolite modified to be Cao-zeolite by ion exchange process using Ca(OH)2. Adsorption test was done on CaO-zeolite with different Ca concentration to understand how it's adsorption phenomena on oxygen and nitrogen. Adsorption test has been done for CaO-zeolite with Ca concentration = 0,682%, 0,849% and 1,244% to oxygen and nitrogen with ...

  2. Hydrothermally grown zeolite crystals

    International Nuclear Information System (INIS)

    Durrani, S.K.; Qureshi, A.H.; Hussain, M.A.; Qazi, N.K.

    2009-01-01

    The aluminium-deficient and ferrosilicate zeolite-type materials were synthesized by hydrothermal process at 150-170 degree C for various periods of time from the mixtures containing colloidal reactive silica, sodium aluminate, sodium hydroxide, iron nitrate and organic templates. Organic polycation templates were used as zeolite crystal shape modifiers to enhance relative growth rates. The template was almost completely removed from the zeolite specimens by calcination at 550 degree C for 8h in air. Simultaneous thermogravimetric (TG) and differential thermal analysis (DTA) was performed to study the removal of water molecules and the amount of organic template cations occluded inside the crystal pore of zeolite framework. The 12-13% weight loss in the range of (140-560 degree C) was associated with removal of the (C/sub 3/H/sub 7/)/sub 4/ N+ cation and water molecules. X-ray diffraction (XRD) analysis and scanning electron microscope (SEM) techniques were employed to study the structure, morphology and surface features of hydrothermally grown aluminium-deficient and ferrosilicate zeolite-type crystals. In order to elucidate the mode of zeolite crystallization the crystallinity and unit cell parameters of the materials were determined by XRD, which are the function of Al and Fe contents of zeolites. (author)

  3. Potentiated clinoptilolite reduces signs and symptoms associated with veisalgia

    Directory of Open Access Journals (Sweden)

    Gandy JJ

    2015-08-01

    Absorbatox™ resulted in an overall significant reduction in central nervous system and gastrointestinal tract symptoms associated with veisalgia, warranting further investigation. Keywords: hangover, clinoptilolite, Absorbatox, alcohol

  4. On the nature of gallium species in gallium-modified mordenite and MFI zeolites. A comparative DRIFT study of carbon monoxide adsorption and hydrogen dissociation.

    Science.gov (United States)

    Serykh, Alexander I; Kolesnikov, Stanislav P

    2011-04-21

    The results of a DRIFT study of carbon monoxide molecular adsorption and hydrogen dissociative adsorption on gallium-modified mordenite and MFI (ZSM-5) zeolites are presented. It was found that in the reduced gallium-modified mordenite (Ga-MOR) both Ga(3+) and Ga(+) exchanged cations are present and can be detected by CO adsorption. Ga(3+) cations in Ga-MOR dissociatively adsorb molecular hydrogen at elevated temperatures, resulting in the formation of gallium hydride species and acidic hydroxyl groups. In the reduced Ga-MFI evacuated at 823 K under medium vacuum conditions only Ga(+) exchanged intrazeolite cations were detected. It was found, however, that Ga(3+) intrazeolite exchanged cations which form upon high-temperature disproportionation of Ga(+) cations in the reduced Ga-MFI and Ga-MOR can be stabilized by high-temperature oxidation of these zeolites.

  5. Elimination of Escherichia coli and Salmonella in Clam by Using Zeolite in a Station of Depuration.

    Science.gov (United States)

    Gdoura, Morsi; Sellami, Hanen; Khannous, Lamia; Ketata, Najib; Neila, Idriss Ben; Traore, Al Ibrahim; Chekir, Zouhair; Gdoura, Radhouane

    2017-09-01

      The application of natural zeolite for water and wastewater treatment has been carried out and is still a promising technique in environmental cleaning processes. Natural zeolite can be used to improve the purification process of clams (Ruditapes decussatus). Thus, our study aimed at improving the clam purification system in order to reduce Escherichia coli and eliminate Salmonella in samples artificially contaminated with this bacterium using a natural zeolite to replace the biological filter. The results showed that zeolite used in a depuration system improved the clam purification process. Moreover, natural zeolite exhibited high performance in the adsorption of bacteria and allowed to reduce the Escherichia coli abundance in 24 h, thus ensuring purified clams conformity with the ISO 16649-3 standard. These results indicate the beneficial effects of using zeolite in the adsorption of bacteria and the reduction in the abundance of Escherichia coli and set the Salmonella from marine organisms.

  6. 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.

  7. Catalysis with hierarchical zeolites

    DEFF Research Database (Denmark)

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

    2011-01-01

    Hierarchical (or mesoporous) zeolites have attracted significant attention during the first decade of the 21st century, and so far this interest continues to increase. There have already been several reviews giving detailed accounts of the developments emphasizing different aspects of this research...... topic. Until now, the main reason for developing hierarchical zeolites has been to achieve heterogeneous catalysts with improved performance but this particular facet has not yet been reviewed in detail. Thus, the present paper summaries and categorizes the catalytic studies utilizing hierarchical...... 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...

  8. The influence of pH on the adsorption of lead by Na-clinoptilolite ...

    African Journals Online (AJOL)

    The influence of pH on the adsorption of lead by Na-clinoptilolite: Kinetic and equilibrium studies. ... At high pH of the contact solution, the adsorption process occurs by ion exchange and at low pH; i.e., it is physical. The variation of the Gibbs free energy demonstrates that adsorption occurs spontaneously. The process was ...

  9. 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.

  10. 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.

  11. 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%.

  12. 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.

  13. Method of processing radioactive liquid wastes by using zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Kanno, T; Mimura, H

    1975-09-18

    The object is to processing radioactive liquid waste by zeolites to be fixed to a solidified body having a very small lixiviation property. The nuclide in radioactive liquid waste is exchanged and adsorbed into natural or synthetic zeolites, which are then burnt to a temperature lower than 1000/sup 0/C -- melting point. Thus, the zeolite structure is broken to form fine amorphous silicate aluminate or silicate aluminate of the nuclide exchanged and adsorbed. Both are very hard to be soluble in water. Further, the lixiviation from the solidified body is limited to the surface thereof, and it will no longer be detected in a few days.

  14. 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...

  15. PREPARATION AND CHARACTERIZATION OF TiO2-ZEOLITE AND ITS APPLICATION TO DEGRADE TEXTILLE WASTEWATER BY PHOTOCATALYTIC METHOD

    Directory of Open Access Journals (Sweden)

    Yeslia Utubira

    2010-06-01

    Full Text Available The preparation of titanium oxide-zeolite composite (TiO2-zeolite has been done. Preparation was initiated by dispersing oligocation of titanium solution into suspension of natural zeolite. The suspension was stirred and then filtered to separate the solid phase from the filtrate. The solid phase was heated by microwave oven to convert the oligocations into its oxide forms and the resulting material (called as TiO2-zeolite then was used to photodegrade the wastewater of PT.Jogjatex The TiO2-zeolite and unmodified zeolite were characterized using X-ray diffractometry, FT-IR spectro-photometry, X-ray fluorescence (XRF and gas sorption analysis (GSA methods to determine their physicochemical properties. Photocatalytic activity of TiO2-Zeolite was tested by exposing the suspension of TiO2-Zeolite/wastewater by the UV light of 366 nm at room temperature for 15 - 75 minutes. Characterization results exhibited that the formation of TiO2 on internal as well as external surfaces of Zeolite could not be detected  with X-ray diffractometry as well as  FT-IR spectrophotometry, however elemental analysis result with XRF indicated that titanium concentration in zeolite increased due to the inclusion, i.e from 0.26% (w/w in zeolite to 2.80% (w/w in TiO2-zeolite. Characterization result by GSA exhibited the increased of specific surface area from 19.57 m2/g in zeolite to 67.96 m2/g in TiO2-zeolite; total pore volume from 20.64 x 10-3 mL/g in zeolite to 49.561 x 10-3 mL/g in TiO2-Zeolite; pore radius average decreased from 21.10 Å in zeolite to 14.58 Å in TiO2-zeolite. Photocatalytic activity test of TiO2-zeolite on wastewater of PT. Jogjatex showed that UV radiation for 75 minutes on the mixture of TiO2-zeolite and wastewater resulted in the decreased of  COD number up to 57.85%. Meanwhile the sorption study showed that zeolite and TiO2-zeolite could decrease COD number of wastewater up to 43.95% and 57.85%, respectively.   Keywords: TiO2-zeolite

  16. CO hydrogenation on zeolite-supported Ru: Effect of neutralizing cations

    International Nuclear Information System (INIS)

    Oukaci, R.; Wu, J.C.S.; Goodwin, J.G. Jr.

    1986-01-01

    Previous results for zeolite-supported Ru prepared by ion exchange suggested a possible effect of the nature and concentration of the neutralizing cations in the zeolite on the catalytic properties of the metal. However, the interpretation of these results was complicated by the fact that a series of zeolites with different Si/Al ratios was used. The present study was undertaken to investigate systematically the influence of the nature of alkali neutralizing cations on CO hydrogenation over ion-exchanged Y-zeolite-supported ruthenium catalysts

  17. 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.

  18. 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.

  19. 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

  20. Advances in nanosized zeolites

    Science.gov (United States)

    Mintova, Svetlana; Gilson, Jean-Pierre; Valtchev, Valentin

    2013-07-01

    This review highlights recent developments in the synthesis of nanosized zeolites. The strategies available for their preparation (organic-template assisted, organic-template free, and alternative procedures) are discussed. Major breakthroughs achieved by the so-called zeolite crystal engineering and encompass items such as mastering and using the physicochemical properties of the precursor synthesis gel/suspension, optimizing the use of silicon and aluminium precursor sources, the rational use of organic templates and structure-directing inorganic cations, and careful adjustment of synthesis conditions (temperature, pressure, time, heating processes from conventional to microwave and sonication) are addressed. An on-going broad and deep fundamental understanding of the crystallization process, explaining the influence of all variables of this complex set of reactions, underpins an even more rational design of nanosized zeolites with exceptional properties. Finally, the advantages and limitations of these methods are addressed with particular attention to their industrial prospects and utilization in existing and advanced applications.

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

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Lu, E-mail: zhanglu1211@gmail.com; Sun, Xiangyang, E-mail: xysunbjfu@gmail.com

    2015-05-15

    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.

  2. 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

  3. DEVELOPMENT OF A UREA BIOSENSOR BASED ON A POLYMERIC MEMBRANE INCLUDING ZEOLITE

    Directory of Open Access Journals (Sweden)

    M. L HAMLAOUI

    2008-06-01

    + -sensitive membrane is based on a zeolite-incorporated polymeric membrane biosensor (clinoptilolite. The sensitivity of ammonium  detection is sub-nernstian (32mV/pNH4 + but the ISFET presents a high selectivity, which is interesting for measurements in biological media. The grafting of urease to the NH4 +-sensitive membrane was permorfed by cross-linking with glutaraldehyde .The sensitivity of the urea ENFET is 15V/purea and this remains stable over 15 days with a detection limit of 3x10-5 M. Finally, in order to test feasibility of the urea biosensor for environmental applications, the remaining activity of the urease was determined after exposure to enzyme inhibiting heavy metals ions such as Hg(II.Using these urea biosensors, a detection limit of less than 5 x 10-8 M was obtained for Hg(II.

  4. 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

  5. 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.

  6. POTASSIUM PERMANGANATE AND CLINOPTILOLITE ZEOLITE FOR IN SITU TREATMENT OF GROUND WATER CONTAMINATED WITH LANDFILL LEACHATE: LABORATORY STUDY

    Science.gov (United States)

    There are tens of thousands of closed landfills in the United States, many of whicih are unlined and sited on alluvial deposits. Landfills are of concern because leachate contains a variety of pollutants that can contaminate ground and surface water. Data from chemical analysis...

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

    International Nuclear Information System (INIS)

    Medina, Adriana; Gamero, Procoro; Almanza, Jose Manuel; Vargas, Alfredo; Montoya, Ascencion; Vargas, Gregorio; Izquierdo, Maria

    2010-01-01

    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 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 2 HAsO 4 .7H 2 O originally containing 740 ppb.

  8. 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.

  9. Effect of Clinoptilolite and Sepiolite Nanoclays on Human and Parasitic Highly Phagocytic Cells

    Directory of Open Access Journals (Sweden)

    Yanis Toledano-Magaña

    2015-01-01

    Full Text Available Nanoclays have potential applications in biomedicine raising the need to evaluate their toxicity in in vitro models as a first approach to its biocompatibility. In this study, in vitro toxicity of clinoptilolite and sepiolite nanoclays (NC was analyzed in highly phagocytic cultures of amoebas and human and mice macrophages. While amebic viability was significantly affected only by sepiolite NC at concentrations higher than 0.1 mg/mL, the effect on macrophage cultures was dependent on the origin of the cells. Macrophages derived from human peripheral blood monocytes were less affected in viability (25% decrease at 48 h, followed by the RAW 264.7 cell line (40%, and finally, macrophages derived from mice bone marrow monocytes (98%. Moreover, the cell line and mice macrophages die mainly by necrosis, whereas human macrophages exhibit increased apoptosis. Cytokine expression analysis in media of sepiolite NC treated cultures showed a proinflammatory profile (INFγ, IL-1α, IL-8, and IL-6, in contrast with clinoptilolite NC that induced lees cytokines with concomitant production of IL-10. The results show that sepiolite NC is more toxic to amoebas and macrophages than clinoptilolite NC, mostly in a time and dose-dependent manner. However, the effect of sepiolite NC was comparable with talc powder suggesting that both NC have low cytotoxicity in vitro.

  10. 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.

  11. 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

  12. Recent Advances in the Mechanistic Studies of Alkylaromatic Conversions over Zeolite Catalysts

    International Nuclear Information System (INIS)

    Min, Hyung-Ki; Hong, Suk Bong

    2013-01-01

    The transformation of alkylaromatic hydrocarbons using zeolite catalysts play big part in the current petrochemical industry. Here we review recent advances in the understanding of the reaction mechanisms of various alkylaromatic conversions with respect to the structural and physicochemical properties of zeolite catalysts employed. Indeed, the shape-selective nature of zeolite catalysts determines the type of reaction intermediates and hence the prevailing reaction mechanism together with the product distribution. The prospect of zeolite catalysis in the development of more efficient petrochemical processes is also described

  13. 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.

  14. Effect of USY zeolite chemical treatment with ammonium nitrate on its VGO hydrocracking performance

    NARCIS (Netherlands)

    Agudelo, J.L.; Hensen, Emiel; Giraldo, S.A.; Hoyos, L.J.

    2016-01-01

    Chemically modified USY zeolites were obtained by ammonium nitrate (AN) treatment under hydrothermal conditions. AN treatment considerably enhanced the mesopore volume of the parent steam-treated zeolite. This treatment also caused the creation of extraframework species of weak acid nature.

  15. 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

  16. 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)

  17. 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.

  18. 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

  19. Reaction mechanisms in zeolite catalysis

    NARCIS (Netherlands)

    Rozanska, X.; Santen, van R.A.; Auerbach, S.C.; Carrado, K.A.; Dutta, P.D.

    2003-01-01

    A review; described are the most basic mechanistic reaction steps that are induced by zeolite catalysts. Details on the zeolitic properties that are relevant to mol. reactivity are also provided. The theor. methods and models at hand to allow the investigation of these reaction steps and that have

  20. Computational approach in zeolite science

    NARCIS (Netherlands)

    Pidko, E.A.; Santen, van R.A.; Chester, A.W.; Derouane, E.G.

    2009-01-01

    This chapter presents an overview of different computational methods and their application to various fields of zeolite chemistry. We will discuss static lattice methods based on interatomic potentials to predict zeolite structures and topologies, Monte Carlo simulations for the investigation of

  1. PHYSICAL, CHEMICAL, AND STRUCTURAL EVOLUTION OF ZEOLITE-CONTAINING WASTE FORMS PRODUCED FROM METAKAOLINITE AND CALCINED HLW

    International Nuclear Information System (INIS)

    Pareizs, J. M.; Jantzenm, C.M.

    2000-01-01

    Natural and synthetic zeolites are extremely versatile materials. They can adsorb a variety of liquids and gases, and also take part in cation exchange reactions. Zeolites have the ability to sequester ions in lattice positions or within their networks of channels and voids. The zeolites can host alkali, alkaline earth and a variety of higher valance cations. As such they may be a viable alternative for immobilization of low activity waste (LAW) salts and calcines. The process for synthesizing zeolites is well documented for pure starting materials. A reactive aluminosilicate is reacted with an alkaline hydroxide at low temperature (<300 C) to form a zeolite. Processing time and temperature and specific reactants determine the type of zeolite formed. Zeolites are easy to make, and can be synthesized from a wide variety of natural and man made materials. However, relatively little is known about the process if one of the starting materials is a poorly characterized complex mixture of oxides (waste) containing nearly every element in the periodic table. The purpose of this work is to develop a clearer understanding of the advantages and limitations of producing a zeolite waste form from radioactive waste. Dr. M. W. Grutzeck at the Pennsylvania State University is investigating the production of a zeolite waste form using nonradioactive simulants. Dr. C. M. Jantzen and J. M. Pareizs at the Savannah River Technology Center will use the results from simulant work as a starting point for producing a zeolite waste form from an actual Savannah River Site radioactive waste stream

  2. Physical, chemical, and structural evolution of zeolite-containing waste forms produced from metakaolinite and calcined HLW

    International Nuclear Information System (INIS)

    Pareizs, J.M.

    2000-01-01

    Natural and synthetic zeolites are extremely versatile materials. They can adsorb a variety of liquids and gases, and also take part in cation exchange reactions. Zeolites have the ability to sequester ions in lattice positions or within their networks of channels and voids. The zeolites can host alkali, alkaline earth and a variety of higher valence cations. As such they may be a viable alternative for immobilization of low activity waste (LAW) salts and calcines. The process for synthesizing zeolites is well documented for pure starting materials. A reactive aluminosilicate is reacted with an alkaline hydroxide at low temperature to form a zeolite. Processing time and temperature and specific reactants determine the type of zeolite formed. Zeolites are easy to make, and can be synthesized from a wide variety of natural and man made materials. However, relatively little is known about the process if one of the starting materials is a poorly characterized complex mixture of oxides (waste) containing nearly every element in the periodic table. The purpose of this work is to develop a clearer understanding of the advantages and limitations of producing a zeolite waste form from radioactive waste. Dr. M. W. Grutzeck at the Pennsylvania State University is investigating the production of a zeolite waste form using non-radioactive simulants. Dr. C. M. Jantzen and J. M. Pareizs at the Savannah River Technology Center will use the results from simulant work as a starting point for producing a zeolite waste form from an actual Savannah River Site radioactive waste stream

  3. 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...

  4. 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...

  5. 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.

  6. 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.

  7. 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.

  8. 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)

  9. PENINGKATAN KECEPATAN PROSES PENGERINGAN KARAGINAN MENGGUNAKAN PENGERING ADSORPSI DENGAN ZEOLIT

    Directory of Open Access Journals (Sweden)

    Mohamad Djaeni

    2012-07-01

    Full Text Available Drying carrageenan product still deals with low product quality and energy efficiency. The drying with airdehumidified by activated natural zeolite has a potential for drying the product. In this concept, air as dryingmedium was contacted with zeolite to reduce its relative humidity. Hence, the driving force of drying increasesand the process can be conducted at moderate temperature (40-60oC to retain the quality. This research looksinto the effectiveness of adsorption dryer with zeolite for drying carrageenan. The natural zeolite is activated byheating 300-400oC for 2-3 hours. The zeolite is then used to dehumidify the ambient air as drying medium. Inthis work, the effect of drying temperature and carrageenan thickness on water content in carrageenan duringthe drying were studied. Results showed with air velocity 3.0 m/sec, thickness of carrageenan 1-2 mm,operational drying time 3 hours and air temperature 40-60oC, water content in carrageenan can be reducedfrom 82.0% to 25%. This result is very promising for industrial application.

  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. Zeolite Combined with Alum and Polyaluminum Chloride Mixed with Agricultural Slurries Reduces Carbon Losses in Runoff from Grassed Soil Boxes.

    Science.gov (United States)

    Murnane, J G; Brennan, R B; Fenton, O; Healy, M G

    2016-11-01

    Carbon (C) losses from agricultural soils to surface waters can migrate through water treatment plants and result in the formation of disinfection by-products, which are potentially harmful to human health. This study aimed to quantify total organic carbon (TOC) and total inorganic C losses in runoff after application of dairy slurry, pig slurry, or milk house wash water (MWW) to land and to mitigate these losses through coamendment of the slurries with zeolite (2.36-3.35 mm clinoptilolite) and liquid polyaluminum chloride (PAC) (10% AlO) for dairy and pig slurries or liquid aluminum sulfate (alum) (8% AlO) for MWW. Four treatments under repeated 30-min simulated rainfall events (9.6 mm h) were examined in a laboratory study using grassed soil runoff boxes (0.225 m wide, 1 m long; 10% slope): control soil, unamended slurries, PAC-amended dairy and pig slurries (13.3 and 11.7 kg t, respectively), alum-amended MWW (3.2 kg t), combined zeolite and PAC-amended dairy (160 and 13.3 kg t zeolite and PAC, respectively) and pig slurries (158 and 11.7 kg t zeolite and PAC, respectively), and combined zeolite and alum-amended MWW (72 and 3.2 kg t zeolite and alum, respectively). The unamended and amended slurries were applied at net rates of 31, 34, and 50 t ha for pig and dairy slurries and MWW, respectively. Significant reductions of TOC in runoff compared with unamended slurries were measured for PAC-amended dairy and pig slurries (52 and 56%, respectively) but not for alum-amended MWW. Dual zeolite and alum-amended MWW significantly reduced TOC in runoff compared with alum amendment only. We conclude that use of PAC-amended dairy and pig slurries and dual zeolite and alum-amended MWW, although effective, may not be economically viable to reduce TOC losses from organic slurries given the relatively low amounts of TOC measured in runoff from unamended slurries compared with the amounts applied. Copyright © by the American Society of Agronomy, Crop Science Society of

  12. The Study on the Effect of Cadmium, Zinc and Zeolite Application on Physiomorphological Characteristics of St. Johnʼs Wort (Hypericum perforatum L.

    Directory of Open Access Journals (Sweden)

    Zhaleh Zandavifard

    2018-02-01

    Full Text Available Introduction: Among the heavy metals, cadmium, because of high mobility and bioavailability in soil and also toxicity at low concentrations is very important. Cadmium (Cd is known as carcinogen and can induce many types of cancers. Human activities (metallic industries, contaminated fertilizer, herbicides or insecticides, irrigation with contaminated groundwater, and use of contaminated sewage sludge are largely responsible for accumulation of different levels of Cd in soil. Saint John’s Wort (Hypericum perforatum L. is a medicinal plant and belongs to the family Hypericaceae which its extract, one of the best-characterized herbal medicines, known as the Cd-hyperaccumulator, is widely sold for the treatment of depression. Hyperaccumulator plants are species able to accumulate high amounts of heavy metals in their tissue at concentrations of 10 to 100 times higher than tolerated by crop plants. Zinc (Zn is an essential element occurring in several enzymes, where it plays a catalytic or structural role. Cadmium and zinc have similar electron configuration, valence state as well as affinity to S, N and O donor ligands and thus their geochemical and environmental properties are comparable. The antagonism activity between Cd and Zn in the environment and their chemical similarity can lead to interactions between Cd and Zn during plant uptake, transport from roots to shoots, or accumulation in edible tissues. Ion exchange is one of the methods used for the removal of several toxic substances. In recent years, natural amendments, such as zeolite have been widely used to address trace metals contamination. Therefore, adding zinc and zeolite to the growth medium of plant can be moderating the toxic effects of cadmium. Materials and Methods: This pot experiment was conducted at the Experimental Field of Ferdowsi University of Mashhad (FUM from September 2013 to June 2014. Treatments consisted of three levels of cadmium (0, 10 and 20 mg Cd kg-1 soil

  13. Sorption of nonpolar aromatic contaminants by chlorosilane surface modified natural minerals.

    Science.gov (United States)

    Huttenloch, P; Roehl, K E; Czurda, K

    2001-11-01

    The efficacy of the surface modification of natural diatomite and zeolite material by chlorosilanes is demonstrated. Chlorosilanes used were trimethylchlorosilane (TMSCI), tert-butyldimethylchlorosilane (TBDMSCI), dimethyloctadecylchlorosilane (DMODSCI), and diphenyldichlorosilane (DPDSCI) possessing different headgroups and chemical properties. Silanol groups of the diatomite and zeolite were modified by chemical reaction with the chlorosilanes resulting in a stable covalent attachment of the organosilanes to the mineral surface. The alteration of surface properties of the modified material was proved by measurements of water adsorption capacity, total organic carbon (TOC) content, and thermoanalytical data. The surface modified material showed great stability even when exposed to extremes in ionic strength, pH, and to pure organic solvents. Sorption of toluene, o-xylene, and naphthalene from water was greatly enhanced by the surface modification compared to the untreated materials which showed no measurable sorption of these compounds. The enhanced sorption was dependent on the organic carbon content as well as on chemical characteristics of the chlorosilanes used. Batch sorption experiments showed that the phenyl headgroups of DPDSCI have the best affinity for aromatic compounds. Removal from an aqueous solution of 10 mg/L of naphthalene, o-xylene, and toluene was 71%, 60%, and 30% for surface modified diatomite and 51%, 30%, and 16% for modified clinoptilolite, respectively. Sorption data were well described by the Freundlich isotherm equation, which indicated physical adsorption onto the lipophilic surface rather than partitioning into the surface organic phase. The chlorosilane modified materials have an apparent potential for application in environmental technologies such as permeable reactive barriers (PRB) or wastewater treatment.

  14. Adsorption methods for hydrogen isotope storage on zeolitic sieves

    International Nuclear Information System (INIS)

    Cristescu, Ioana; Cristescu, Ion; Vasut, F.; Brad, S.; Lazar, A.

    2001-01-01

    For hydrogen isotope separation, adsorption molecular sieves and active carbon were used. Adsorption process proceeds at liquid nitrogen and liquid hydrogen temperatures. Commercial zeolites have the same proprieties with natural zeolites, but they have a regular pore structure. They also have affinity for molecules of different size with defined shapes. Experimental results obtained at liquid nitrogen temperature (77.4 K) and liquid hydrogen revealed the efficient behaviour of the active carbon and zeolitic sieves for hydrogen isotopes temporary storage. We study adsorption of the synthetic zeolites in a wide range of temperatures and pressures and we used the molecular sieves 4A, 5A and active carbon. The 4A and 5A zeolites have a tridimensional structure with 11.4 A diameter. When the hydration water is eliminated, the material keeps a porous structure. The porous volume represents 45% from the zeolite mass for 4A and 5A sieves. The activation temperature of the zeolite and the carbon is very important for obtaining a high adsorption capacity. If the temperature used for activation is low, the structural water will be not eliminated and the adsorption capacity will be low. The excessive temperature will destroy the porous structure. The adsorption capacity for the hydrogen isotopes was calculated with the relation: A = V ads /m (cm 3 /g). The adsorption capacity and efficiency for the adsorbent materials, are given. Physical adsorption process of the hydrogen isotopes was carried out at liquid nitrogen temperature. The flux gas used in the adsorption system is composed of dry deuterium and protium. This mixture is cooled in liquid nitrogen and then is passed to the adsorbent getter at the same temperature (77.4 K). The gas flux in the adsorbent getter is 5 and 72 l/h (which correspond to 0.008 and 0.134 discharge velocity, respectively). (authors)

  15. Fluorescence labelling as tool for zeolite particle tracking in nanoremediation approaches

    International Nuclear Information System (INIS)

    Gillies, Glenn; Mackenzie, Katrin; Kopinke, Frank-Dieter; Georgi, Anett

    2016-01-01

    Colloidal Fe-zeolites such as Fe-BEA-35 are currently under study as new adsorbent and catalyst materials for in-situ chemical oxidation with H_2O_2. As for nanoremediation in general, the availability of suitable particle detection methods is a requirement for successful process development and particle tracing. Detection and distinguishing between natural colloids and introduced particles with a similar composition are a challenge. By means of fluorescence labelling, a highly specific detection option for Fe-BEA-35 was developed. ‘Ship-in-a-bottle’ synthesis of fluorescein within the zeolite pores, which was applied for the first time for a BEA type zeolite, provides a product with stable and non-extractable fluorescence. When the fluorescent labelled zeolite is added at a concentration of 1 wt.% referring to the total zeolite mass, a very low detection limit of 1 mg/L of total zeolite is obtained. Compared to commonly applied turbidity measurements, detection via fluorescence labelling is much more specific and sensitive. Fluorescence is only marginally affected by carboxymethyl cellulose, which is frequently applied as stabilizer in application suspensions but will be depleted upon contact with H_2O_2. Transport properties of fluorescent labelled and non-labelled Fe-zeolite particles are in agreement as determined in a column study with quartz sand and synthetic groundwater (classified as very hard). - Highlights: • Fluorescent BEA zeolite was prepared for first time by ‘ship-in-a-bottle’ synthesis. • Fluorescein synthesized inside zeolite channels is stable and non-extractable. • Detection limit of Fe-zeolite particles in suspension with 1 wt.% fluorescent zeolite is 1 mg/L. • Transport properties of fluorescent and Fe-loaded BEA particles are identical.

  16. Redox properties of phenosafranine at zeolite-modified electrodes-Effect of surface modification and solution pH

    International Nuclear Information System (INIS)

    Easwaramoorthi, S.; Natarajan, P.

    2008-01-01

    Redox properties of cationic dye phenosafranine (3,7-diamino-5-phenylphenazenium chloride) (PS + ) were studied at zeolite-modified electrodes using Zeolite-Y and NaZSM-5. The peak current and peak potential of phenosafranine-adsorbed zeolite were found to be influenced by the pH of the electrolyte solution. Observation of a second redox couple is suggested to be due to formation of new species at low concentration from the reduced phenosafranine at the zeolite-modified electrodes. Titanium dioxide nanoparticles encapsulated in the cavities of the zeolite or anchored on the external surface of the zeolite do not seem to affect the redox properties of adsorbed PS + . When the cyclic voltammograms are recorded immediately after the electrode is immersed into the solution, the redox potential of PS + is found to be sensitive to the nature of the zeolite surface. The peak potential shifts towards positive region under continuous cycles as the surface hydroxyl groups get protonated in acidic electrolyte solution thereby forcing the movement of dye molecules from the zeolite surface to the zeolite electrode solution interface. The electron transfer rate constants for the adsorbed dye at the electrode are calculated to be 2.5 ± 0.2 s -1 and 3.5 ± 0.2 s -1 for the zeolite-Y electrode and the ZSM-5 electrode, respectively by the Laviron equation

  17. 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.

  18. 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

  19. Zeolites for nitrosamine and pharmaceutical removal from demineralised and surface water: Mechanisms and efficacy

    KAUST Repository

    De Ridder, David J.; Verberk, J. Q J C; Heijman, Sebastiaan G J; Amy, Gary L.; Van Dijk, Johannis C.

    2012-01-01

    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

  20. Electron beam irradiation and zeolites adsorption applied to dyeing effluents

    International Nuclear Information System (INIS)

    Higa, Marcela C.; Fungaro, Denise A.; Somessari, Elizabeth S.R.; Magdalena, Carina P.; Grosche, Lucas C.; NNeto, Antonio C.; Borrely, Sueli I.

    2007-01-01

    Wastewater generated from the textile industries contain large amount of azo dyes and many of them present low biodegradability capability. Today several countries are facing with evidences that water pollution is related to toxicity, mutagenicity and carcinogenic nature. Once reactive dyes are commercial products they will be discharged to the waterways and rivers causing ecological damages and health problems. The aim of this paper was to consider the potential of two techniques for colour and toxicity removal: ionizing radiation and adsorption by zeolites synthesized from fly ash. Real effluents from chemical and textile industries (hardly coloured) were submitted to radiation and adsorption using zeolites. It was necessary to dilute some effluents prior the treatments in order to get any success. When electrons irradiation was performed radiation doses applied were from 0.5 kGy up to 20 kGy. This radiation process accounted for a partial decolouring as higher doses were implemented. Coal fly ashes were used as starting material for zeolite synthesis by means of hydrothermal treatment with alkaline medium. The adsorption was performed by batch experiments. It was obtained about 77% - 90% color removal from dye wastewater after 24h of contact time with two types of zeolite. The irradiation accounted for 72% of the initial toxicity. The ionizing radiation and adsorption by zeolites synthesized from fly ash can be used as an alternative for the treatment of aqueous waste containing dyes. (author)

  1. Light-refractory radiation shielding materials using diatomites and zeolites

    International Nuclear Information System (INIS)

    Murakami, Hideki

    2005-01-01

    It has been recently shown that diatomites and zeolites have some useful characteristics for radiation shielding materials. In this study, the availability of these materials for unexpected accidents in the nuclear sites is examined. The diatomites and zeolites, compared to existing shielding materials, have superior characteristics; low density and light weight, low in radiation-induced problem, high-heat resistance, remain unaltered by the addition of an acid except hydrofluoric acid, porous and large specific surface area, and also excellent water-absorbing property. These porous materials could also expand the shielding energy range applied and be used for fast- and thermal-neutrons, and γ ray. In addition, these materials are easy to store for long periods of time against emergency because of their natural rocks. From the examinations, it is cleared that diatomites and zeolites have excellent properties as radiation shielding materials for emergency use. (author)

  2. 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)

  3. 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

    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....... Natural zeolite at a dose of 40 g/L resulted in the largest increase (29%) in total CH4 yield from swine manure compared to the nil zeolite treatments. The lag phase of digestion was decreased with increasing zeolite doses up to 100 g/L. Natural and sodium zeolites at a dose of 100 g/L reduced NH4 + by 50...

  4. [Preparation of HDTMA-modified Zeolite and Its Performance in Nitro-phenol Adsorption from Wastewaters].

    Science.gov (United States)

    Guo, Jun-yuan; Wang, Bin

    2016-05-15

    In this study, natural zeolite was modified by HDTMA. Effects of the modified conditions, HDTMA-modified zeolite doses, solution pH values, and reaction time on nitro-phenol removal were investigated, and the adsorption kinetics and isotherms were discussed. Compared with natural zeolite, HDTMA-modified zeolite showed better performance in nitro-phenol removal. An adsorption capacity of 2.53 mg · g⁻¹ was achieved when the concentration of HDTMA solution (pH = 10) was 1.2% in preparation of modified zeolite. This adsorption capacity was higher than that obtained by natural zeolite (0.54 mg · g⁻¹). In adsorption tests, when HDTMA- modified zeolite dose was adjusted to 8 g · L⁻¹, the removal efficiency of nitro-phenol reached 93.9% after 90 min reaction, with wastewater pH of 6. Furthermore, the nitro-phenol adsorption process could be well fitted to the pseudo-first-order kinetics model (R² > 0.90), whereas the adsorption isotherm results indicated that Langmuir model provided the best fitting for the equilibrium data at different temperatures, with R² of higher than 0.90.

  5. Bio-based phenolic-branched-chain fatty acid isomers synthesized from vegetable oils and natural monophenols using modified h+-ferrierite zeolite

    Science.gov (United States)

    A new group of phenolic branched-chain fatty acids (n-PBC-FA), hybrid molecules of natural monophenols (i.e., thymol, carvacrol and creosote) and mixed fatty acid (i.e., derived from soybean and safflower oils), were efficiently produced through a process known as arylation. The reaction involves a...

  6. Removal of paraquat solution onto zeolite material

    Science.gov (United States)

    Sirival, Rujikarn; Patdhanagul, Nopbhasinthu; Preecharram, Sutthidech; Photharin, Somkuan

    2018-04-01

    The purpose of this research was to study the adsorption of paraquat herbicides onto zeolite Y materials by the batch method. Three adsorbents material: Zeolite-3, Zeolite-10, and Zeolite-100 were Si/Al ratio at 3.58, 8.57 and 154.37, respectively. The factors for adsorption of paraquat as follows, adsorption time, initial concentrations of paraquat, pH and adsorption isotherm were investigated. The results showed that zeolite-10 had higher adsorption capacity than zeolite-3 and zeolite-100. The appropriate conditions for adsorption were 24 h., Zeolite 0.1 g., Initial paraquat concentration 100 ppm at pH 6. The adsorption isotherm was found to correspond with Langmuir Isotherm and the maximum paraquat adsorption is 26.38 mg/g for zeolite-10, 21.41 mg/g and 9.60 mg/g for zeolite-3 and zeolite-100, respectively. The characterization of zeolite material with XRD, XRF and BET. Furthermore, the zeolite materials applied to remove other organic and inorganic wastewater.

  7. 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.

  8. Zeolite/magnetite composites as catalysts on the Synthesis of Methyl Esters (MES) from cooking oil

    Science.gov (United States)

    Sriatun; Darmawan, Adi; Sriyanti; Cahyani, Wuri; Widyandari, Hendri

    2018-05-01

    The using of zeolite/magnetite composite as a catalyst for the synthesis of methyl esters (MES) of cooking oil has been performed. In this study the natural magnetite was extracted from the iron sand of Semarang marina beach and milled by high energy Milling (HEM) with ball: magnetite ratio: 1:1. The composites prepared from natural zeolite and natural magnetite with zeolite: magnetite ratio 1:1; 2:1; 3:1 and 4:1. Preparation of methyl ester was catalyzed by composite of zeolite/magnetite through transeserification reaction, it was studied on variation of catalyst concentration (w/v) 1%, 3%, 5% and 10% to feed volume. The reaction product are mixture of methyl Oleic (MES), methyl Palmitic (MES) and methyl Stearic (MES). Character product of this research include density, viscosity, acid number and iodine number has fulfilled to SNI standard 7182: 2015.

  9. Hierarchical zeolites: progress on synthesis and characterization of mesoporous zeolite single crystal catalysts

    DEFF Research Database (Denmark)

    Kustova, Marina; Egeblad, Kresten; Christensen, Claus H.

    2007-01-01

    Recently, a new family of crystalline zeolitic materials was reported, the so-called mesoporous zeolite single crystals featuring individual zeolite single crystals with an additional noncrystalline mesopore system interconnected with the usual micropore system of the zeolite, resulting...... measurements. Additionally, the results of diffusion of n-hexadecane in conventional and mesoporous zeolites are presented. Isomerization and cracking of n-hexadecane was chosen as model test reaction for these materials. All results support that mesoporous zeolites are superior catalysts due to improved mass...... transport. Importantly, the mesoporous zeolites show significant improved resistance to poisoning by carbon formation....

  10. Multicolor photoluminescence in ITQ-16 zeolite film

    KAUST Repository

    Chen, Yanli; Dong, Xinglong; Zhang, Zhenyu; Feng, Lai

    2016-01-01

    Exploring the native defects of zeolites is highly important for understanding the properties of zeolites, such as catalysis and optics. Here, ITQ-16 films were prepared via the secondary growth method in the presence of Ge atoms. Various intrinsic

  11. A method for removing sulfur bearing compounds from paraffinous hydrocarbons or a directly distilled benzine fraction

    Energy Technology Data Exchange (ETDEWEB)

    Konyukhova, T.P.; Bolotskaya, I.A.; Mikhaylova, L.A.; Sadykov, A.N.; Shitovkin, N.T.; Vlasov, V.V.

    1983-01-01

    In the known method for removing sulfurorganic compounds from paraffinous hydrocarbons or a directly distilled gasoline fraction through their adsorption using natural zeolite, in order to increase the degree of purification, clinoptilolite (Kp), which contains SiO2 and A12O3 in a molar ratio of 10.6 to 16.7 is used as the natural zeolite. The purification of the paraffinous hydrocarbons through clinoptilolite adsorption as compared with mordenite adsorption makes it possible to increase the degree of their purification of ethylmercaptane and dimethylsulfide. The effectiveness of clinoptilolite is also confirmed in removing mercaptanes and sulfides from directly distilled gasoline fractions.

  12. Examination of zeolites by neutron reflection method

    International Nuclear Information System (INIS)

    Szegedi, S.; Varadi, M.; Boedy, Z.T.; Vas, L.

    1991-01-01

    Neutron reflection method has been used for the determination of zeolite content in minerals. The basis of this measurement is to observe the large difference between the water content of zeolite and that of other mineralic parts of the sample. The method suggested can be used in a zeolite mine for measuring the zeolite content continuously and controlling the quality of the end products. (author) 5 refs.; 3 figs.; 3 tabs

  13. Influence of Zeolite Coating on the Corrosion Resistance of AZ91D Magnesium Alloy.

    Science.gov (United States)

    Banerjee, P Chakraborty; Woo, Ren Ping; Grayson, Sam Matthew; Majumder, Amrita; Raman, R K Singh

    2014-08-22

    The protective performance of zeolite coating on AZ91D magnesium alloy was evaluated using potentiodynamic polarisation and electrochemical impedance spectroscopy (EIS) in 0.1 M sodium chloride solution (NaCl). Electrical equivalent circuit (EEC) was developed based upon hypothetical corrosion mechanisms and simulated to correspond to the experimental data. The morphology and the chemical nature of the coating were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. Post corrosion morphologies of the zeolite coated and the uncoated AZ91D alloy were investigated using SEM. The corrosion resistance of the zeolite coated specimen was at least one order of magnitude higher than the uncoated specimen.

  14. Introduction to zeolite theory and modelling

    NARCIS (Netherlands)

    Santen, van R.A.; Graaf, van de B.; Smit, B.; Bekkum, van H.

    2001-01-01

    A review. Some of the recent advances in zeolite theory and modeling are present. In particular the current status of computational chem. in Bronsted acid zeolite catalysis, mol. dynamics simulations of mols. adsorbed in zeolites, and novel Monte Carlo technique are discussed to simulate the

  15. 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,

  16. 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

  17. Ammonium removal from high-strength aqueous solutions by Australian zeolite

    DEFF Research Database (Denmark)

    Wijesinghe, D. Thushari N; Dassanayake, Kithsiri B.; Sommer, Sven G.

    2016-01-01

    Removal of ammonium nitrogen (NH4 +-N) particularly from sources which are highly rich in nitrogen is important for addressing environmental pollution. Zeolites, aluminosilicate minerals, are commonly used as commercial adsorbents and ion-exchange medium in number of commercial applications due...... to its high adsorption capacity of ammonium (NH4 +). However, detailed investigations on NH4 + adsorption and ion exchange capacities of Australian natural zeolites are rare, particularly under higher NH4 + concentrations in the medium. Therefore, this study was conducted to determine NH4 + adsorption...... characteristics of Australian natural zeolites at high NH4 + concentrations with and without other chemical compounds in an aqueous solution. Results showed that initial NH4 + concentration, temperature, reaction time, and pH of the solution had significant effects on NH4 + adsorption capacity of zeolite...

  18. Zeolitic adsorbent synthesized from powdered waste porcelain, and its capacity for heavy metal removal

    International Nuclear Information System (INIS)

    Wajima, T.; Ikegami, Y.

    2006-01-01

    A zeolitic adsorbent was synthesized from powdered waste porcelain kept at 80 o C for 24 h. The product contained the zeolite phases Na-P1 and hydroxysodalite. The product with the highest cation exchange capacity (CEC) was synthesized using 4 M NaOH and the sample weight / volume of alkali solution ratio was 1/4. The highest CEC obtained for the product was almost 1900 mmol/kg, which is the same as that of natural zeolite. The product with the highest CEC was tested for its ability to remove heavy metals (Fe, Cu, Ni, Zn, Pb, Cd, Mn, Cr, Al, B,Mo) from an acidic solution (pH 2). The product can neutralize the acidic solution to almost pH 7, and the capacity of the product for the removal of heavy metals is higher than that of the natural zeolite, except for Mo and B. (authors)

  19. Producing zeolites from fly ash

    International Nuclear Information System (INIS)

    Rayalu, S.; Labhestwar, N.K.; Biniwale, R.B.; Udhoji, J.S.; Meshram, S.U.; Khanna, P.

    1998-01-01

    Fly ash has virtually become a menace of thermal power generation, leading to its devastating effects on the environment. Development of alternate methods of its disposal - especially those with recourse to recovery of valuable materials-has thus become imperative. This paper deals with the utilisation of fly ash for the production of high value-added products, viz., commercial grade zeolites. The physico-chemical and morphological characteristics of fly ash based Zeolite-A (FAZ-A) compares well with commercial Zeolite-A. High calcium binding capacity, appropriate particle/pore size and other detergency characteristics of FAZ-A brings forth its potential as a substitute for phosphatic detergent builder. The technology is extremely versatile, and other products like Zeolite-X, Zeolite-Y, sodalite and mordenite are also amenable for cost effective production with modifications in certain reaction parameters. Low temperature operations, ready availability of major raw materials, simplicity of process and recycling of unused reactants and process water are special features of the process. (author)

  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. Magnetic zeolites a and p synthesized from kaolin: synthesis and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Bessa, R.A.; Oliveira, C.P.; Nascimento, R.F.; Bohn, F.; Loiola, A.R. [Universidade Federal do Ceara (UFCE), CE (Brazil)

    2016-07-01

    Full text: Zeolites are hydrated aluminosilicates of open chain, formed by silica and alumina tetrahedral structures linked by common oxygen atoms, generating interconnected pores and cages with molecular dimensions and well defined sizes that limit matter transference between internal surface and application medium. They can be found naturally or synthesized using different aluminum and silicon sources that may modify the produced zeolite. Their industrial application has grown enormously over the last century. However, a big issue that still remains is the difficulty in retrieving zeolite powders when used in aqueous media. This work reports the use of kaolin as an alternative raw material for zeolite syntheses by means of hydrothermal route and subsequent preparation of magnetic composites through magnetite impregnation. The syntheses of two different zeolites were carried out by mixing appropriate amounts of metakaolin (kaolin previously calcined at 600 deg C for 2 h), sodium metasilicate and sodium hydroxide solution, aged for 18 h and heated at 100 °C for 4-48 h. After these processes, the final materials were washed several times with distilled water, filtered and dried at 80 deg C for 12 h. Magnetic composites were prepared by impregnating the zeolites with of Fe3O4 nanoparticles (NP) synthesized by the partial oxidation and precipitation of Fe2+ ions. The obtained materials were characterized by X-ray diffraction, scanning electron microscopy, FTIR spectroscopy and magnetization measurements. The results of XRD and FTIR provide evidence of the success in the synthesis of both zeolites A and P as well as Fe3O4. Subsequently, composites were formed by mixtures of zeolite A + NP and zeolite P + NP. The existence of secondary crystalline phases was also confirmed. However, it did not interfered significantly in the results as these phases appear as minor amounts and are most likely residues from the clay used as the main silica and alumina sources. Scanning

  2. Suspending Zeolite Particles In Tanks

    International Nuclear Information System (INIS)

    Poirier, M.R.

    1999-01-01

    The Savannah River Site (SRS) is in the process of removing waste (sludge and salt cake) from million gallon waste tanks. The current practice for removing waste from the tanks is adding water, agitating the tanks with long shaft vertical centrifugal pumps, and pumping the sludge/salt solution from the tank to downstream treatment processes. This practice has left sludge heels (tilde 30,000 gallons) in the bottom of the tanks. SRS is evaluating shrouded axial impeller mixers for removing the sludge heels in the waste tanks. The authors conducted a test program to determine mixer requirements for suspending sludge heels using the shrouded axial impeller mixers. The tests were performed with zeolite in scaled tanks which have diameters of 1.5, 6.0, and 18.75 feet. The mixer speeds required to suspend zeolite particles were measured at each scale. The data were analyzed with various scaling methods to compare their ability to describe the suspension of insoluble solids with the mixers and to apply the data to a full-scale waste tank. The impact of changes in particle properties and operating parameters was also evaluated. The conclusions of the work are: Scaling of the suspension of fast settling zeolite particles was best described by the constant power per unit volume method. Increasing the zeolite particle concentration increased the required mixer power needed to suspend the particles. Decreasing the zeolite particle size from 0.7 mm 0.3 mm decreased the required mixer power needed to suspend the particles. Increasing the number of mixers in the tank decreased the required mixer power needed to suspend the particles. A velocity of 1.6 ft/sec two inches above the tank bottom is needed to suspend zeolite particles

  3. Detergent zeolite complex "Alusil", Zvornik

    OpenAIRE

    Stanković Mirjana S.; Pezo Lato L.

    2003-01-01

    The IGPC Engineering Department designed the basis technological and machine projects for a detergent zeolite complex, on the basis of which a pilot plant with an initial capacity of 5,000 t/y was constructed in 1983 within Birač-Zvornik production complex. Additional projects were done afterwards and the starting capacity increased to 200,000 t/y in 1988. This plant became the biggest producer of detergent zeolite in the world. These projects were manufactured on the basis of specific techno...

  4. Effect of Fe3O4 addition on removal of ammonium by zeolite NaA.

    Science.gov (United States)

    Liu, Haibo; Peng, Shuchuan; Shu, Lin; Chen, Tianhu; Bao, Teng; Frost, Ray L

    2013-01-15

    Magnetic zeolite NaA with different Fe(3)O(4) loadings was prepared by hydrothermal synthesis based on metakaolin and Fe(3)O(4). The effect of added Fe(3)O(4) on the removal of ammonium by zeolite NaA was investigated by varying the Fe(3)O(4) loading, pH, adsorption temperature, initial concentration, adsorption time. Langmuir, Freundlich, and pseudo-second-order modeling were used to describe the nature and mechanism of ammonium ion exchange using both zeolite and magnetic zeolite. Thermodynamic parameters such as change in Gibbs free energy, enthalpy and entropy were calculated. The results show that all the selected factors affect the ammonium ion exchange by zeolite and magnetic zeolite, however, the added Fe(3)O(4) apparently does not affect the ion exchange performance of zeolite to the ammonium ion. Freundlich model provides a better description of the adsorption process than Langmuir model. Moreover, kinetic analysis indicates the exchange of ammonium on the two materials follows a pseudo-second-order model. Thermodynamic analysis makes it clear that the adsorption process of ammonium is spontaneous and exothermic. Regardless of kinetic or thermodynamic analysis, all the results suggest that no considerable effect on the adsorption of the ammonium ion by zeolite is found after the addition of Fe(3)O(4). According to the results, magnetic zeolite NaA can be used for the removal of ammonium due to the good adsorption performance and easy separation method from aqueous solution. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. Hydrothermal conversion of FAU zeolite into RUT zeolite in TMAOH system

    OpenAIRE

    Jon, Hery; Takahashi, Shoutarou; Sasaki, Hitoshi; Oumi, Yasunori; Sano, Tsuneji

    2008-01-01

    The highly crystalline and pure RUT (RUB-10) zeolite could be obtained from the hydrothermal conversion of FAU zeolite used as a crystalline Si/Al source in tetramethylammonium hydroxide (TMAOH) media. As compared to amorphous silica/Al(OH)3 and amorphous silica/γ-Al2O3 sources, the crystallization rate for the formation of RUT zeolite was clearly faster when FAU zeolite was employed as the Si/Al source. Moreover, it was found that the hydrothermal conversion of FAU zeolite into RUT zeolite d...

  6. 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.

  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. 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.

  9. Removal of Na+ from Ionic Liquids by Zeolite for High Quality Electrolyte Manufacture

    International Nuclear Information System (INIS)

    Cho, Wonje; Seo, Yongseong; Jung, Soon Jae; Lee, Won Gil; Kim, Byung Chul; Yu, Kookhyun

    2013-01-01

    This study develops a novel method to remove the free cations created during the synthesis of ionic liquid. The cations are removed from the ionic liquid by size-selective adsorption onto chemically surface-modified Zeolite. The porous crystal nano-structure of Zeolite has several electron-rich Al sites to attract cations. While large cations of an ionic liquid cannot access the Zeolite nano-structure, small cations like Na + have ready access and are adsorbed. This study confirms that: Na + can be removed from ionic liquid effectively using Zeolite; and, in contrast to the conventional and extensively applied ion exchange resin method or solvent extraction methods, this can be done without changing the nature of the ionic liquid

  10. 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)

  11. 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)

  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. Copper nanoparticles in zeolite Y

    NARCIS (Netherlands)

    Seidel, A.; Loos, J.; Boddenberg, B.

    1999-01-01

    CuCl has been dispersed in the supercages of a Y-type zeolite by heating a mechanical salt/host mixture in vacuo. The occluded salt was subsequently reduced to copper metal in a hydrogen atmosphere. Virtually complete reduction of the salt is achieved at 460°C. Under the same conditions,

  14. Homogeneous versus heterogeneous zeolite nucleation

    NARCIS (Netherlands)

    Dokter, W.H.; Garderen, van H.F.; Beelen, T.P.M.; Santen, van R.A.; Bras, W.

    1995-01-01

    Aggregates of fractal dimension were found in the intermediate gel phases that organize prior to nucleation and crystallization (shown right) of silicalite from a homogeneous reaction mixture. Small- and wide-angle X-ray scattering studies prove that for zeolites nucleation may be homogeneous or

  15. 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

  16. 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

  17. ETHIOPIAN NATURAL ZEOLITES FOR PHOTOCATALYSIS Kiros ...

    African Journals Online (AJOL)

    B. S. Chandravanshi

    treatment, photochemical synthesis and water splitting for energy purpose. Of the many tested ... Sample characterization. Powder X-ray diffraction ... is expected to be related to the Ilmenite phase (FeTiO3), although the coexistence of Ti in the.

  18. Positron spectroscopy studies of zeolites

    Science.gov (United States)

    Hung, Ku-Jung

    The lineshapes of two-dimensional angular correlation of electron-positron annihilation radiation (2D-ACAR) in alumina and several zeolites were measured as a function of internal surface areas. In all cases, the lineshape parameter S from 2D-ACAR spectra were found to vary proportionally with internal surface area. In order to investigate the Bronsted acidity in NaHY zeolite, the lineshape parameter evaluation from 2D-ACAR measurements for varied acidity in NaHY zeolites by ion-exchange and thermal desorption were presented. The result from this investigation has demonstrated that the Bronsted acidity in NaHY zeolite was found to vary linearly with the lineshape parameter of the angular correlation spectrum of the sample. The lineshapes of 2D-ACAR spectra were determined for different base adsorbed HY-zeolite samples under a temperature controlled heating system in order to investigate, in-situ, the acid strength and number of Bronsted acid sites in the sample. Results have shown that the lineshape parameter of the angular correlation spectrum of the sample increases with the strength of adsorbed base and decreases with the number of Bronsted acid sites in the sample. This indicated that the lineshape parameter is sensitive to all of the strengths and concentrations of Bronsted acid sites in the HY-zeolite samples. The result from this study has also demonstrated that the large size base, pyridine, would reduce the possibility of positronium formation in the sample by filling the cage to eliminate the internal surface areas where the positroniums are likely to form. However, the small size base, ammonia, did not show any effect on the internal surface areas. Owing to the fact that this technique monitors only the Bronsted acid sites that situate on the surface which relates to the catalytic activity, there is little ambiguity about the location of the source of information obtained. The findings presented in this dissertation point out the fact that such lineshape

  19. The effect of zeolite treatment by acids on sodium adsorption ratio of coal seam gas water.

    Science.gov (United States)

    Wang, Xiaoyu; Ozdemir, Orhan; Hampton, Marc A; Nguyen, Anh V; Do, Duong D

    2012-10-15

    Many coal seam gas (CSG) waters contain a sodium ion concentration which is too high relative to calcium and magnesium ions for environment acceptance. Natural zeolites can be used as a cheap and effective method to control sodium adsorption ratio (SAR, which is a measure of the relative preponderance of sodium to calcium and magnesium) due to its high cation exchange capacity. In this study, a natural zeolite from Queensland was examined for its potential to treat CSG water to remove sodium ions to lower SAR and reduce the pH value. The results demonstrate that acid activated zeolite at 30%wt solid ratio can reduce the sodium content from 563.0 to 182.7 ppm; the pH from 8.74 to 6.95; and SAR from 70.3 to 18.5. Based on the results of the batch experiments, the sodium adsorption capacity of the acid-treated zeolite is three times greater than that of the untreated zeolite. Both the untreated and acid-treated zeolite samples were characterized using zeta potential, surface characterization, DTA/TG and particle size distribution in order to explain their adsorption behaviours. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Investigating the Influence of Temperature on the Kaolinite-Base Synthesis of Zeolite and Urease Immobilization for the Potential Fabrication of Electrochemical Urea Biosensors.

    Science.gov (United States)

    Anderson, David Ebo; Balapangu, Srinivasan; Fleischer, Heidimarie N A; Viade, Ruth A; Krampa, Francis D; Kanyong, Prosper; Awandare, Gordon A; Tiburu, Elvis K

    2017-08-08

    Temperature-dependent zeolite synthesis has revealed a unique surface morphology, surface area and pore size which influence the immobilization of urease on gold electrode supports for biosensor fabrication. XRD characterization has identified zeolite X (Na) at all crystallization temperatures tested. However, N₂ adsorption and desorption results showed a pore size and pore volume of zeolite X (Na) 60 °C, zeolite X (Na) 70 °C and zeolite X (Na) 90 °C to range from 1.92 nm to 2.45 nm and 0.012 cm³/g to 0.061 cm³/g, respectively, with no significant differences. The specific surface area of zeolite X (Na) at 60, 70 and 90 °C was 64 m²/g, 67 m²/g and 113 m²/g, respectively. The pore size, specific surface area and pore volumes of zeolite X (Na) 80 °C and zeolite X (Na) 100 °C were dramatically increased to 4.21 nm, 295 m²/g, 0.762 cm³/g and 4.92 nm, 389 m²/g, 0.837 cm³/g, in that order. The analytical performance of adsorbed urease on zeolite X (Na) surface was also investigated using cyclic voltammetry measurements, and the results showed distinct cathodic and anodic peaks by zeolite X (Na) 80 °C and zeolite X (Na) 100 °C. These zeolites' molar conductance was measured as a function of urea concentration and gave an average polynomial regression fit of 0.948. The findings in this study suggest that certain physicochemical properties, such as crystallization temperature and pH, are critical parameters for improving the morphological properties of zeolites synthesized from natural sources for various biomedical applications.

  1. 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

  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. 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 no