The effect of the acid pretreatment temperature of natural diatomaceous earth on the Si/Al ratio of ZSM-5 zeolite

La tierra de diatomea boliviana es una fuente de silicio potencialmente más económica en comparación a los reactivos de alta pureza comúnmente utilizados para la síntesis de zeolitas. Dada su composición compleja es necesario realizarle un pretratamiento ácido con el fin de reducir las impurezas y regular el contenido de aluminio. En este artículo se realizaron múltiples experimentos durante la etapa de pretratamiento ácido. La temperatura del pretratamiento ácido fue modificada en un rango entre 50 y 155 °C esto con el fin de determinar su efecto en la relación Si/Al final. Los resultados mostraron que la relación Si/Al puede ser modulada en un rango entre 6,2 y 38,1. Posteriormente, se obtuvieron zeolitas a partir de la tierra de diatomea modificada. Las zeolitas obtenidas presentaron una relación Si/Al entre 9,6 y 40,2. Se aplicaron distintas técnicas de caracterización para la determinación de las propiedades. El grado de cristalinidad y el área superficial específica están directamente relacionadas con la relación Si/Al. Los sitios ácidos están conformados por ácidos fuertes de tipo Brönsted y ácidos fuertes y débiles de tipo Lewis. Para la zeolita con menor relación Si/Al se determinó una elevada acidez total (>0,51 molNH3/Kgzeolita), mientras que para la zeolita con mayor relación Si/Al la acidez total se redujo considerablemente (<0,38 molNH3/Kgzeolita).

Bolivian diatomaceous earth is a potentially lower cost silica source than conventional high purity reagents used in zeolite synthesis. Due to its complex composition, it is necessary to pre-treat it with sulfuric acid in order to reduce impurities and regulate the aluminum content. In the present work several experiments were carried out with natural Bolivian diatomaceous earth in the pre-treatment stage. In order to determine the effect on the final Si/Al ratio, the temperature of the acid pre-treatment was varied between 50 to 155 °C. The results show that the Si/Al ratio can be modulated from 6.2 up to 38.1. These treated diatomaceous earth samples were used to synthetise ZSM-5 zeolite. The obtained ZSM-5 zeolites have a Si/Al ratio in the following range: 9.6 to 40.2. XRD, NH3-TPD and Nitrogen Physisorption techniques were used to characterise the properties of the obtained zeolites. The degree of crystallisation and the specific surface area are directly related to the Si/Al ratio, resulting in high values at high Si/Al ratios. The acid sites are composed of strong Brönsted acid sites and, strong and weak Lewis acid sites. For the zeolite with a low Si/Al ratio a high total acidity was found (>0.51 molNH3/Kgzeolite), while at high Si/Al ratios the total acidity is reduced (<0.38 molNH3/Kgzeolite).

A terra diatomácea boliviana é uma fonte potencialmente mais barata de silício em comparação com os reagentes de alta pureza comumente usados para a síntese de zeólitas. Dada a sua composição complexa, é necessário realizar um pré-tratamento ácido para reduzir as impurezas e regular o teor de alumínio. No presente trabalho, vários experimentos foram realizados durante a etapa de pré-tratamento ácido. A temperatura do pré-tratamento ácido foi modificada em uma faixa entre 50 e 155 °C para determinar seu efeito na relação Si/Al final. Os resultados mostram que a razão Si/Al pode ser modulada em uma faixa entre 6,2 e 38,1. Posteriormente, as zeólitas foram obtidas a partir de terra diatomácea modificada. As zeólitas obtidas possuem uma razão Si/Al entre 9,6 e 40,2. Diferentes técnicas de caracterização foram aplicadas para determinar as propriedades. O grau de cristalinidade e a área superficial específica estão diretamente relacionados com a razão Si/Al. Os sítios ácidos são compostos por ácidos fortes do tipo Brönsted e ácidos fortes e fracos do tipo Lewis. Para a zeólita com menor relação Si/Al, foi determinada uma alta acidez total (>0,51 molNH3/Kgzeólita), enquanto para a zeólita com maior relação Si/Al, a acidez total foi consideravelmente reduzida (<0,38 molNH3/Kgzeolita).

Encapsulation of Metarhizium anisopliae spores with zeolite nanoparticles and magnesium silicate nanoparticles against mortality and lethal times of Crocidolomia pavonana larvae

Aims@#Cruciferae crops failure such as cabbage generally due to heavy attacks by of Crocidolomia pavonana larvae. Metarhizium anisopliae is a species of fungus that can infect more than 200 insect pests including C. pavonana larvae. However, the direct application of M. anisopliae spore in the field is susceptible to UV rays from the sun, which can decrease the efficiency of M. anisopliae. Thus, this study aims to investigate the encapsulation performance of M. anisopliae spore with zeolite and magnesium silicate nanoparticles in terms of mortality and lethal time against 3 rd instar C. pavonana larvae.@*Methodology and results@#Zeolite and magnesium silicate nanoparticles were chosen because they are non-toxic, environmentally friendly and able to maintain moisture, so that they are best used as protective materials for spores. The experiment was designed by Randomized Block Design (RBD) with a single factor. The obtained results showed that encapsulation of M. anisopliae spores with zeolite nanoparticles coating agent increased the mortality rate to 92.5% and accelerated the lethal time up to 1.075 days compared to only spore correspondingly 27.5% and 2.235 days. The M. anisopliae spores encapsulated with magnesium silicate nanoparticles also increased the mortality to 85.0% and accelerated the larval lethal time up to 1.150 days.@*Conclusion, significance and impact of study@#Metarhizium anisopliae spores that encapsulated with zeolite nanoparticles coating received higher mortality and faster lethal time to C. pavonana compared to those encapsulated with magnesium silicate nanoparticles. The encapsulation formulation of these two coatings can be used as bioinsecticide in controlling C. pavonana larvae.

Preparation of adsorbents for selectively removal of heavy metals from Salvia miltiorrhiz extract / 中草药

Objective: Taking molecular sieve as a main component, to develop adsorbents which can selectively remove five kinds of heavy metal in Salvia miltiorrhiz extract solution. Methods: The 13X zeolite powder and active alumina powder were selected to compose adsorbent from four materials including iron red powder, fast powder (activated alumina), 13X molecular sieve powder, and zinc sulfide powder. The adsorbent formula was optimized with uniform design for mixture experiment. Pore-expanding agents, such as Chitisan and EDTA, were added to improve adsorbent pore structure. Results: With uniform design for mixture experiment, adsorbents with 13X zeolite ratio 0.275 6—0.465 5 could effectively remove five heavy metals (Cu, Pb, Cd, Hg, and As) in water solution. The optimal adsorbents from uniform design were hard to remove heavy metal in S. miltiorrhiz extract solution in 4 h, and removal ratios of Cu, Pb, Cd, Hg, and As were 14.4%, 74.5%, 54.6%, 13.4%, and 8.8%, respectively. With the same formula, pore- expanding adsorbents could effectively remove five heavy metals in S. miltiorrhiz extract solution in 4 h, and removal ratios of Cu, Pb, Cd, Hg, and As increased to 21.0%, 91.5%, 97.5%, 60.3%, and 46.8%, respectively. Conclusion: Pore-expanding adsorbents prepared in this study could remove five heavy metals in S. miltiorrhiz extract solution in short time, exhibiting industrial application prospect.

Analysis of Small Molecules by Matrix Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry with Porous Zeolite Supported α-Cyano-4-Hydroxycinnamic Acid as Composite Matrix / 分析化学

Zeolite supportedα-cyano-4-hydroxycinnamic acid ( CHCA) as novel composite matrix was applied in matrix assisted laser desorption ionization time-of-flight mass spectrometry ( MALDI-TOF-MS ) analysis of substance P and small molecular compounds of fluoroquinolones. In the experiment, this new matrix was examined and compared with conventional organic matrix CHCA. The results indicated that the novel composite matrix was capable of suppressing the alkali metal related peaks and interference fragments, simplifying mass spectra in low-molecular-weight region, and promoting ionization efficiency. The influence of SiO2/Al2 O3 ratio of ZSM-5 and porous diameter of ZSM-5 and Beta zeolites on performance of MALDI-TOF-MS analysis of substance P was also investigated under the same conditions. In contrast, it was regarded that the strong surface acidity and sufficient cavity for loading CHCA were beneficial for interference fragments suppression and peak intensity enhancement. Additionally, it was successfully applied in the detection of enrofloxacin and ciprofloxacin in complex samples.

Analysis of Small Molecules by Matrix Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry with Porous Zeolite Supported α-Cyano-4-Hydroxycinnamic Acid as Composite Matrix / 分析化学

Zeolite supportedα-cyano-4-hydroxycinnamic acid ( CHCA) as novel composite matrix was applied in matrix assisted laser desorption ionization time-of-flight mass spectrometry ( MALDI-TOF-MS ) analysis of substance P and small molecular compounds of fluoroquinolones. In the experiment, this new matrix was examined and compared with conventional organic matrix CHCA. The results indicated that the novel composite matrix was capable of suppressing the alkali metal related peaks and interference fragments, simplifying mass spectra in low-molecular-weight region, and promoting ionization efficiency. The influence of SiO2/Al2 O3 ratio of ZSM-5 and porous diameter of ZSM-5 and Beta zeolites on performance of MALDI-TOF-MS analysis of substance P was also investigated under the same conditions. In contrast, it was regarded that the strong surface acidity and sufficient cavity for loading CHCA were beneficial for interference fragments suppression and peak intensity enhancement. Additionally, it was successfully applied in the detection of enrofloxacin and ciprofloxacin in complex samples.

Effectiveness of thymoquinone, zeolite, and platelet-rich plasma in model of corrosive oesophagitis induced in rats

PURPOSE: The effectiveness of platelet-rich plasma (PRP), thymoquinone, and zeolite in corrosive esophageal burns was investigated in a rat model. METHODS: Four groups were comprised as containing 10 rats in each group. For group I, oesophagitis was induced and no other procedure was performed (control group). For group II, oesophagitis was induced and thymoquinone was administered for 1 week via oral gavage once a day (thymoquinone group). For group III, oesophagitis was induced for 1 week via oral gavage once a day (PRP group). For group IV, oesophagitis was induced and zeolite was administered for 1 week via oral gavage once a day (zeolite group). On the 10th day, the rats were sacrificed under anaesthesia and venous blood sampling was performed from the vena portae. The oesophaguses were totally excised. Biochemically, interleukin (IL)-1B, IL-6, TNF-α, and MCP-1 were examined from venous blood. Inflammation score was evaluated histopathologically in oesophageal tissue that was collected. RESULTS: There was a statistically significant difference among groups in terms of IL-1, IL-6, MCP levels, compared to the control group; median IL-1, IL-6, MCP levels of thymoquinone, PRP, and zeolite groups were statistically significantly lower. There was a statistically significant difference among groups in terms of inflammation scores, compared to group I; median inflammation scores of groups II, III and IV were statistically significantly lower thymoquinone. CONCLUSION: PRP, and zeolite exhibited positive effect on recovery in oesophagitis by reducing inflammation in the involved segment.

Geophagy (rock eating), experimental stress and cognitive idiosyncrasy

<p><b>OBJECTIVE</b>To discusse the impact of geophagy on behavior and conditioned-reflex activity of Wistar rats subjected to instrumental stress under experimental conditions.</p><p><b>METHODS</b>Experimental geophagy was simulated by adding zeolite-containing tuff (clinoptilolite) to animal feed, the amount relating to 2% of body mass. Tuff was obtained from areas where animals usually eat subsurface rock. Search activity of animals and peculiarities of information and emotional stress were studied through the use of a universal problem chamber.</p><p><b>RESULTS</b>The results of this experimental study showed the negative impact of instrumental stress on laboratory animals, manifested in behavioral dysfunction, in the form of changes in qualitative and quantitative characteristics of search activity. Experimental geophagy contributed to significant improvement in behavioral parameters, confirming the anti-stress effects of the use of natural ingredients.</p><p><b>CONCLUSIONS</b>These results suggest that, in natural environmental conditions, "edible" rocks serve as an adaptive tool for recovery from various types of environmental stresses, and are examples of self-medication.</p>

Geophagy (rock eating), experimental stress and cognitive idiosyncrasy

Objective:To discusse the impact of geophagy on behavior and conditioned-reflex activity of Wistar rats subjected to instrumental stress under experimental conditions. Methods:Experimental geophagy was simulated by adding zeolite-containing tuff (clinoptilolite) to animal feed, the amount relating to 2%of body mass. Tuff was obtained from areas where animals usually eat subsurface rock. Search activity of animals and peculiarities of information and emotional stress were studied through the use of a universal problem chamber. Results: The results of this experimental study showed the negative impact of instrumental stress on laboratory animals, manifested in behavioral dysfunction, in the form of changes in qualitative and quantitative characteristics of search activity. Experimental geophagy contributed to significant improvement in behavioral parameters, confirming the anti-stress effects of the use of natural ingredients. Conclusions:These results suggest that, in natural environmental conditions,ediblerocks serve as an adaptive tool for recovery from various types of environmental stresses, and are examples of self-medication.

Geophagy (rock eating), experimental stress and cognitive idiosyncrasy

Objective: To discusse the impact of geophagy on behavior and conditioned-reflex activity of Wistar rats subjected to instrumental stress under experimental conditions. Methods: Experimental geophagy was simulated by adding zeolite-containing tuff (clinoptilolite) to animal feed, the amount relating to 2% of body mass. Tuff was obtained from areas where animals usually eat subsurface rock. Search activity of animals and peculiarities of information and emotional stress were studied through the use of a universal problem chamber. Results: The results of this experimental study showed the negative impact of instrumental stress on laboratory animals, manifested in behavioral dysfunction, in the form of changes in qualitative and quantitative characteristics of search activity. Experimental geophagy contributed to significant improvement in behavioral parameters, confirming the anti-stress effects of the use of natural ingredients. Conclusions: These results suggest that, in natural environmental conditions, "edible" rocks serve as an adaptive tool for recovery from various types of environmental stresses, and are examples of self-medication.

Antimicrobial effects of silver zeolite, silver zirconium phosphate silicate and silver zirconium phosphate against oral microorganisms

<p><b>OBJECTIVE</b>To evaluate the antimicrobial activities of silver inorganic materials, including silver zeolite (AgZ), silver zirconium phosphate silicate (AgZrPSi) and silver zirconium phosphate (AgZrP), against oral microorganisms. In line with this objective, the morphology and structure of each type of silver based powders were also investigated.</p><p><b>METHODS</b>The antimicrobial activities of AgZ, AgZrPSi and AgZrP were tested against Streptococcus mutans, Lactobacillus casei, Candida albicans and Staphylococcus aureus using disk diffusion assay as a screening test. The minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) were determined using the modified membrane method. Scanning electron microscope and X-ray diffraction were used to investigate the morphology and structure of these silver materials.</p><p><b>RESULTS</b>All forms of silver inorganic materials could inhibit the growth of all test microorganisms. The MIC of AgZ, AgZrPSi and AgZrP was 10.0 g/L whereas MLC ranged between 10.0-60.0 g/L. In terms of morphology and structure, AgZrPSi and AgZrP had smaller sized particles (1.5-3.0 µm) and more uniformly shaped than AgZ.</p><p><b>CONCLUSIONS</b>Silver inorganic materials in the form of AgZ, AgZrPSi and AgZrP had antimicrobial effects against all test oral microorganisms and those activities may be influenced by the crystal structure of carriers. These results suggest that these silver materials may be useful metals applied to oral hygiene products to provide antimicrobial activity against oral infection.</p>

Antimicrobial effects of silver zeolite, silver zirconium phosphate silicate and silver zirconium phosphate against oral microorganisms

Objective: To evaluate the antimicrobial activities of silver inorganic materials, including silver zeolite (AgZ), silver zirconium phosphate silicate (AgZrPSi) and silver zirconium phosphate (AgZrP), against oral microorganisms. In line with this objective, the morphology and structure of each type of silver based powders were also investigated. Methods: The antimicrobial activities of AgZ, AgZrPSi and AgZrP were tested against Streptococcus mutans, Lactobacillus casei, Candidaalbicans and Staphylococcus aureus using disk diffusion assay as a screening test. The minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) were determined using the modified membrane method. Scanning electron microscope and X-ray diffraction were used to investigate the morphology and structure of these silver materials. Results: All forms of silver inorganic materials could inhibit the growth of all test microorganisms. The MIC of AgZ, AgZrPSi and AgZrP was 10.0 g/L whereas MLC ranged between 10.0-60.0 g/L. In terms of morphology and structure, AgZrPSi and AgZrP had smaller sized particles (1.5-3.0 μm) and more uniformly shaped than AgZ. Conclusions: Silver inorganic materials in the form of AgZ, AgZrPSi and AgZrP had antimicrobial effects against all test oral microorganisms and those activities may be influenced by the crystal structure of carriers. These results suggest that these silver materials may be useful metals applied to oral hygiene products to provide antimicrobial activity against oral infection.

CoolClot, a novel hemostatic agent for controlling life-threatening arterial bleeding / 世界急诊医学杂志（英文）

@#BACKGROUND: Uncontrolled bleeding is the first leading cause of preventable death in the battlefield and the 2nd cause of mortality in civil accidents. Incompressible hemorrhage control is among the interventions that drastically increase the survival rate in wound individuals. We have previously shown that a certain mixture of bentonite and zeolite minerals can significantly decrease the bleeding in rats. METHODS: In this study, nine healthy hybrid dogs were selected and after induction of anesthesia with ether, either arterial puncture by a needle or arteriotomy was performed on both groin regions of the dogs. For control arteries (either the right or left femoral artery), only pressure by sterilized gauze was performed, while for the femoral arteries of the opposite side, our invented hemostatic agent, namely CoolClot, was topically used before applying the pressure. In the second stage of the study, to assess the coagulation time, blood samples were collected from 10 volunteer students. RESULTS: CoolClot significantly decreased the bleeding time in animals whose femoral arteries were cut or punctured. In the human phase of the study, the mean coagulation time in control blood samples was 253.4±44.1 seconds, whereas it was 149.5±50.0, 162.3±74.6 and 143.4±114.6 seconds, respectively in blood samples treated with bentonite, zeolite and CoolClot (P<0.05). CONCLUSIONS: As controlling bleeding after a life-threatening arterial damage is critical for increasing the chance of survival, the results obtained in this study indicate the significant efficacy of CoolClot in shortening the bleeding time. Our experiments also indicate that CoolClot can significantly reduce the clotting time in human blood samples.

The study of plants and minerals with wound-healing activities / Монголын Анагаах Ухаан

BackgroundThe works done during the research include: conducting photochemical study on the surface of the piece of land on which the medicinal herbs chosen as samples for the research grow; extracting dry infusion from plants; identifying main substance and antibacterial activity of dry infusion; conducting pilot pharmacological experiment with mineral samples.GoalBased on the results of these experiments, we aimed at finding out wound healing functions of Chelidonium majus. L, Stellerae chamaejasme.L etc, widely used in both conventional and modern medicine as well as of such minerals as Sinder, Zeolite, Tormohon, Baragshun after selecting from them.Materials and MethodsAlkaloid, a biologically active substance found in surface of plant land and dry infusion, was determined by titration method, alkaloids such as protopine and berberine by high performance liquid chromatography, coumarin and flavonoid by spectrophotometric method, the amount of infusible substance by scale method. The methodologies of Gatsura.N and Avtandilov.G.G were adopted to make artificial wound on skin and to heal a wound respectively.ResultsAs the research result shows, the surface of the area where Stellerae chamaejasme.L grow, contains 0.33% ±0.004 total coumarin, 0.19 % ±0.002 flavonoid and 37.14 % ±0.61 infusible substance while that of Chelidonium majus.L contains 0.19% ±0.003 total alkaloid, 0.12 % ±0.004 flavonoid, 0.09 % ±0.002 coumarin and 36.27%±0.74 infusible substance. After the infusion was extracted from Stellerae chamaejasme.L and Chelidonium majus.L through method of percolation with mixer, there were 16% and 14.5% dry substance remained in the infusions respectively. These figures were reduced to 12.6% and 11.4% after freezing them in -500C for 72 hours in dry freezing. The fact that total coumarin contained in dry infusion of Stellerae chamaejasme.L is 2.95% and protopine and berberine in that of Chelidonium majus.L, is 28 мг,% and 3.7 мг,% respectively meets the requirements for medicinal plant extracts. It was found during the pharmacological experiment of preparing 25% oil ointment composed of minerals including Sinder, Tormohon, Zeolite, Baragshun that zeolite was the highest effective mineral in healing a wound by wound index. Therefore, we chose zeolite as an ingredient of the wound ointment. Oil ointments of 6 variations with 5% and 10% content were prepared from the dry infusion as well as minerals of the study plants, and pilot pharmacological experiment was conducted on an experimental mouse that had an artificial wound. The result of the experiment proved that oil ointments with 5% content of Stellerae chamaejasme.L, Chelidonium majus.L and zeolite were more effective in healing the wound than others.ConclusionBy photochemical analysis, the chosen plants proved to be meeting the requirements for medicinal plants. Pilot pharmacological experiment showed that zeolite was the one that accelerated a wound healing process more efficiently than others. Oil ointments with 5% content of dry infusion and 5% of zeolite were effective in healing a wound quickly.

Nutrient release by a Brazilian sedimentary zeolite

This report describes the characterization of a sedimentary occurrence from the Parnaíba Basin, Brazil, containing the zeolite stilbite intertwined with smectitic clay mineral. The head samples from different sites present a wide content range of the zeolitic phase - 15 percent to 50 percent. The use of simple separation techniques - conventional gravitic treatments - yields concentrates containing about 67 percent of the zeolitic component. Assays with the amendments of these concentrates with plant nutrients yield release rates matching those reported for similar commercial products.

São apresentadas as propriedades físico-químicas de uma ocorrência sedimentar da Bacia do Parnaíba, Brasil, da zeólita estilbita, agregada a uma argila esmectítica. As amostras de diferentes sítios apresentam uma ampla variação do mineral zeolítico: entre 15 por cento a 50 por cento. A utilização de espirais concentradoras foi suficiente para obtenção de concentrados contendo até 67 por cento do mineral. Ensaios laboratoriais do concentrado dopado com fertilizantes revelam taxas de liberação de nutrientes comparáveis aos obtidos com produtos comerciais similares.

Evaluación del ffecto de la impregnación de plaino sobre las características ssuperficiales y estructurales de una zeolita y / Evauation of thee platinum impregnaion effect on the surface and sstructure features of a zeolite y / Avaliação do efeito da impregnação da platina sore as características superficiiais e estruturais de uma zeolita y

El presente artículo muestra la evaluación de los cambios texturales, superficiales y estructurales en una zeolita Y empleada en la síntesis de sólidos a base de platino soportado. Las características estructurales se analizaron mediante difracción de rayos X (DRX), y las propiedades texturales y morfológicas mediante fisiadsorción de nitrógeno a 77K y microscopía electrónica de barrido (SEM). Adicionalmente, se determinó la dimensión fractal y la distribución de potenciales de adsorción para todos los sólidos. Los resultados muestran que el proceso de síntesis induce la formación de microporosidad en los sólidos, conservando la estructura de la zeolita y sin ocasionar alteraciones topográficas o energéticas importantes sobre la superficie del soporte.

The present paper shows the evaluation of texture, surface and structure changes on a zeolite Y employed in the synthesis of solids based on supported platinum. The structure features were analyzed by X-ray diffraction (XRD) whereas the texture and morphologic properties were studied from nitrogen adsorption isotherms (77K) and scanning electron microscopy (SEM). In addition, fractal dimension and adsorption potential distribution were determinedall solids. The results show that the synthesis process induces the microporosity formation, maintaining the zeolite structure and without important topographic or energetic alterations on the surface.

O presente artigo mostra a avaliação das mudanças texturais, superficiais e estruturais em uma zeolita Y empregada na síntese de sólidos na base de platina suportada. As características estruturais foram analisadas mediante difração de raios X (DRX) e as propriedades texturais e morfológicas mediante fisiadsorção de nitrogênio a 77K e microscopia eletrônico de varredura (SEM). Adicionalmente se determinou a dimensão fractal e a distribuição dos potenciais de adsorção para todos os sólidos. Os resultados mostram que o processo da síntese induz a formação da microporosidade, conservando a estrutura da zeolita sem causar alterações topográficas ou energéticas importantes sobre a superfície de suporte.

Modificaciones ee las propiedades texturales y structurales de una zeolita usyy y de sus mezclas con "caolín clay" y clorhidrol como consecuencia del tratamiento hidrotérmico / Modifications of the textural and structural proprties of zeolite usy and its miixture with kaolin clay and chlorhydrol as consequence of the hydrothermal treatment

El catalizador de FCC está constituido por partículas de composición compleja donde el componente activo es una zeolita Y. En este trabajo se presentan los resultados texturales y estructurales de una zeolita USY comercial lixiviada, de una serie de catalizadores con 7, 15, 25, 35 y 45% de material activo y los de estos materiales desactivados hidrotérmicamente. Las muestras se caracterizaron por fluorescencia de rayos X (FRX), difracción de rayos X (DRX), resonancia magnética nuclear de silicio (29Si RMN) y fisiadsorción de nitrógeno a 77 K. A partir de estos resultados se hallaron correlaciones entre el volumen de microporo y el contenido de zeolita y entre el grado de cristalinidad y el porcentaje de zeolita. Además, se encontró que un tratamiento con sólo 20% de vapor de agua a 1033 K durante 16 horas destruye los grupos estructurales Si(2Al) y Si(3Al) como reflejo de la dealuminización drástica que sufre el material.

FCC catalyst is made up of particles of complex composition where the main active component is a Y zeolite. This work presents the textural and structural results of a commercial USY zeolite which had been previously prepared from a set of catalysts with 7, 15, 25, 35 y 45% of active material and of the hydrothermally deactivated materials zeolite. The samples have been characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), 29Si NMR spectroscopy and nitrogen adsorption at 77K. From these results was found correlations between micropore volume and zeolite content and degree crystallinity and %zeolite. Also, it was found that an hydrothermal treatment at 1033 K with only 20% steam during 16 hours destroys the structural groups Si(2Al) and Si(3Al) as a reflection of the strongly dealumination of the zeolite component of the catalyst.

Analysis for the Performance of Zeolite 5A Molecular Sieve to Adsorb CO_2 in Crew Module / 航天医学与医学工程

Objective To analyze the performance of adsorbing CO2 with zeolite 5A molecular sieve in crew module. Methods Fitting analysis was based on experimental data of adsorbing CO2,O2 and N2 with zeolite 5A molecular sieve and the suitability of isotherm adsorbing equation of Langmuir,Freundlich and BET models to be conducted with Origin software. Then using obtained equations and competitive adsorbing theory,the adsorbed amounts of these three kinds of gas under competitive condition were calculated. Results The constants in equations for adsorbing CO2,O2 and N2 with zeolite 5A molecular sieve were determined,and adsorbed amounts for above three kinds of gases under competitive condition were calculated. Conclusion The adsorbed CO2 amount is affected by high fraction of N2. Therefore zeolite 5A molecular sieve should be modified technically so that its adsorption in N2 might be reduced to an ignored amount.

Treatment of Fluoride in Groundwater with Activated Zeolite / 环境与健康杂志

Objective To verify that natural zeolites can be used in treatment of fluoride in groundwater in the east-southern of Shanxi Province. Methods Determination of the fluoride by lime-paper sampling and fluorine ion-selective electrode analysis(reference to GB/T 7484-1987). In the paper the best activation process and the appropriate application were discussed, and then the activated zeolite should be used in experimental and real application, in which the effect of zeolite on water quality were assured. The used zeolite could be regenerated and reused. Results The best activation process before use was orderly treated by 5.0 mol/L HCl for 5 hours, then 0.3 mol/L KAl(SO4)2 10 hours,and finally 300 ℃ in furnace for 4 hours. 5 g activated zeolite in 100 ml water(solid∶liquid =1∶20). The static analysis insisted that activated zeolite had a significant adsorption for fluorine. The dynamic analysis verified that the fluoride level could reach the standard after 40 min of treatment. Regenerated with 2.0% KAl(SO4)2,the effect of removing fluoride was 45.0%. Conclusion The experiments testified that the processed natural zeolite can used in water treatment of high fluoride groundwater.

Biocmpatibility research of a hemostatic agent-ZSM-5 zeolite / 医疗卫生装备

Objective To evaluate the biocompatibility of ZSM-5 zeolite and provide an experimental basis for developing the first-aid hemostatic agent.Methods According to Chinese evaluation standards on medical devices and biological tests,the cytotoxicity in vitro,hemolysis test,acute toxicity of system,pyrogen test,intracutaneous stimulation,sensitization and micronucleus test were studied in ZSM-5 zeolite.In order to find out the side-effect of the zeolite granules' remains left in the wounds to body,muscle implantation test was studied.Results There were no obvious cytotoxity,hemolysis reaction.Acute tocicity,pyrogen reaction,intraeutaneous stimulation,sensitization and potential mutagenesis in themicronucleus test were observed.Their results were a11 consistent with the Chinese biological evaluation of medical devices.Obvious inflammatory reaction was observed when ZSM-5 zeolite was implanted in muscle for 12 weeks.Conclusion The ZSM-5 zeo1ite has reliable biocompatibility.But zeolite can cause inflammatory reaction when it is remained in the wound surface for long term.