Synthesis of Zeolites

It is unclear why disease occurs in only a small proportion of persons carrying common risk alleles of disease susceptibility genes. Here we demonstrate that an interaction between a specific virus infection and a mutation in the Crohn's disease susceptibility gene Atg16L1 induces intestinal pathologies in mice. This virus-plus-susceptibility gene interaction generated abnormalities in granule packaging and unique patterns of gene expression in Paneth cells. Further, the response to injury induced by the toxic substance dextran sodium sulfate was fundamentally altered to include pathologies resembling aspects of Crohn's disease. These pathologies triggered by virus-plus-susceptibility gene interaction were dependent on TNFa and IFNg and were prevented by treatment with broad spectrum antibiotics. Thus, we provide a specific example of how a virus-plus-susceptibility gene interaction can, in combination with additional environmental factors and commensal bacteria, determine the phenotype of hosts carrying common risk alleles for inflammatory disease.

Virtually every tissue of the adult organism maintains a population of putatively slowly-cycling stem cells that maintain homeostasis of the tissue and respond to injury when challenged. These cells are regulated and supported by the surrounding microenvironment, referred to as the stem cell ‘niche’. The niche includes all cellular and non-cellular components that interact in order to control the adult stem cell, and these interactions can often be broken down into one of two major mechanistic categories—physical contact and diffusible factors. The niche has been studied directly and indirectly in a number of adult stem cell systems. Herein, we will first focus on the most well-understood niches supporting the germline stem cells in the lower organisms Caenorhabditis elegans and Drosophila melanogaster before concentrating on the more complex, less well-understood mammalian niches supporting the neural, epidermal, haematopoietic and intestinal stem cells. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

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 75 min. 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 feed-stocks 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 styr-ene, 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 40.2–45 MJ/kg, which are similar to conventional diesel. The liquid oil has potential to be used as an alternative source of energy or fuel production.

The capture of CO 2 is motivated by the forecasted alteration in the global climate, which has resulted from the worlds reliance on fossil fuels for energy generation. Controlling CO 2 emissions to stabilize global warming is an essential challenge for the future. Various separation technologies such as chemical absorption, adsorption, cryogenics, membranes, and microbial/algal systems can be applied to capture CO 2 from gas mixtures, and these are commercial activities that occur in hydrogen, ammonia, and natural gas purification plants. Nevertheless, chemical absorption and adsorption are currently believed to be the most appropriate methods for postcombustion power plants. Typically, CO 2 is vented to the atmosphere, and in some cases, it is captured and reused. The present primary applications of CO 2 include enhanced oil recovery (EOR) and the carbonated beverages industry. The conventional method for CO 2 capture for this technique is through solvent-based absorption. It is still unclear whether this technology will be the optimal method to tackle the amount of CO 2 released on an annual basis ( % 30 Gt worldwide). The current technologies of synthesized gas mixtures that consist of CO 2 from power plants have led to a dramatic expansion of research developments and several concepts related to clean energy conversion processes. The principle of thermodynamic laws sets boundaries on the minimum work required for CO 2 separation. Actual separation processes will come with irreversibility, which will result in inefficiencies. Factors affecting these efficiencies depend on the operational conditions, maintenance, and capital costs. Gas stor-age in porous solids such as activated carbons, zeolites, porous coordination polymers (PCPs), and metal-organic frameworks (MOFs) has become a very attractive option for various environmental applications. For a provided set of pressure, volume, and temperature parameters for the unit operations, specifically at low to moderate pressures, more gas can be stored in adsorbent-filled tanks rather than under uncontrolled conditions. In this method, the efficient storage of CO 2 for overall use remains an elusive topic. Several examples available in the literature are restricted to long-term storage for environmental applications as a target for reduced carbon emissions and short-term storage for which recovery of the gas is necessary for a subsequent process. This includes CO 2 reduction for resource recovery in portable closed-volume settings, such as submarines or spaceships. For these particular applications, the adsorption-based storage of CO 2 presents safety and economic advantages, as both high pressures and high energy inputs can be avoided while retaining a maximum storage capacity. Adsorbents that exhibit steep, linear, and reversible isotherms are desirable, as a small variation in pressure produces a relatively high unloading of CO 2 . Hence, adsorption reversibility and total delivery capacity under nonequilibrium conditions should be With increasing carbon dioxide (CO 2 ) emissions from the combustion of fossil-based fuels, the concentration of CO 2 in the atmosphere is growing at 407.54 parts per million, as released in May 2016. Accordingly, the reduction of CO 2 emissions is an essential issue for global climate changes. Tremendous efforts have been directed towards the goal of CO 2 separation and capture. These have led to the development of novel classes of porous materials that possess unique potential applications in the capture and sequestration of CO 2 . Hence, this comprehensive review focuses on studying and analyzing newly developed methods to reduce greenhouse gas emissions and to sequester CO 2 released from anthropogenic activities. It compares and analyzes, in terms of storage capacity and adsorption selectivity, the innovative technologies that capture CO 2 . Also described are the key advancements in CO 2 capture from chemical absorption post-and precombustion industrial units and its subsequent physical adsorption by using various zeolites and metal-organic framework (MOF) materials for CO 2 adsorption, storage, and separation. Current progress in MOF materials for CO 2 capture is considered, and the potentials and limitations of new discoveries in the area are addressed, as it is a rapidly growing area. Furthermore, trends in the design of various kinds of porous structures with tailored macro-and microstructures and target surface properties are examined.

ZSM-22/polyethersulfone membranes were prepared for salt rejection using modelled brackish water. The membranes were fabricated via direct ZSM-22 incorporation into a polymer matrix, thereby inducing the water permeability, hydrophilicity and fouling resistance of the pristine polyethersulfone (PES) membrane. A ZSM-22 zeolite material with a 60 Si/Al ratio, high crystallinity and needle-like morphologies was produced and effectively used as a nanoadditive in the development of ZSM-22/PES membranes with nominal loadings of 0-0.75 wt.%. The characterisation and membrane performance evaluation of the resulting materials with XRD, BET, FTIR, TEM, SEM and contact angle as well as dead-end cell, respectively, showed improved water permeability in comparison with the pristine PES membrane. These ZSM-22/PES membranes were found to be more effective and superior in the processing of modelled brackish water. The salt rejection of the prepared membranes for NaCl and MgCl 2 was effective, while they exhibited quite improved water flux and flux recovery ratios in the membrane permeability and anti-fouling test. This indicates that different amounts of ZSM-22 nanoadditives produce widely divergent influences on the performance of the pristine PES membrane. As such, over 55% of salt rejection is observed, which means that the obtained membranes are effective in salt removal from water.

The optimization of methane conversion to liquid fuels over copper loaded W/ZSM-5 catalyst was studied by utilizing experimental design from 'Statsoft Statistica' version 6.0 software. Response surface methodology was employed to determine the optimum methane conversion and C 5 þ selectivity. Numerical results indicated the optimum methane conversion of 29.4% with the corresponding C 5 þ selectivity of 57.2% were achieved at 12.3 vol% of O 2 , 203.9 ml/min of total feed flow rate, and %W doped of 3.2 wt%. The optimum C 5 þ selectivity of 70.2% was attained at 7.6 vol% of O 2 , 208.9 ml/min of total feed flow rate, and 3.2 wt% of W content with the corresponding methane conversion of 26.7%. By means of variance analysis and additional experiments, the adequacy of this model is confirmed.

This study aims to examine the effect of zeolites in optimizing the process of food waste composting. A novel method of sequential hydrothermal was introduced to modify the natural zeolite and apply to in-vessel compost bioreactors. Raw and modified natural zeolites were applied at 10 and 15% (w/w) of the total waste and compared with un-amended control trial. Both raw and modified zeolites affected the composting process, but the notable results were observed for modified natural zeolite. The results for compost stability parameters were prominent at 15% modified natural zeolite concentration. The rapid and long-term thermophillic temperature and moisture content reduction to the optimum range was observed for modified natural zeolite. Furthermore, the total ammonium (NH 4 +) and nitrate (NO 3 −) concentration in modified natural zeolite were increased by 11.1 and 21.5% respectively as compared to raw zeolite. Compost stability against moisture contents (MC), electrical conductivity (EC), organic matters (OM), total carbon (TC), mineral nitrogen, nitrification index (NI) and germination index (GI) was achieved after 60 days of composting that was in accordance with the international compost quality standards. The findings of this study suggested the suitability of modified natural zeolite addition at 15% to the total waste as the optimum ratio for the composting of food waste in order to achieve a stable nutrient-rich compost.

In the present work, palladium nanoparticles supported on hierarchical ZSM-5 zeolite (Pd/H-hierarchical ZSM-5) was evaluated as a novel acid-metal bi-functional heterogeneous catalyst for direct one-pot reductive amination of nitroarenes using aldehyde in the presence of NaBH4 and water as a mild reducing agent and green solvent, respectively. The structural and morphological properties of the prepared catalyst were investigated by XRD, BET, FT-IR, NH3-TPD, SEM, TEM, XPS, DRS-UV and ICP-AES techniques. The reaction was carried out at room temperature, in short reaction time without producing any by-products. The stability of the catalyst was good and it could be reused six times without much loss of activity in reductive amination reaction.

Synthesis of zeolitic minerals (Na–X and HS) by the use of natural materials (naturally zeolitised alkaline volcanic rocks and
‘‘Tripoli’’) has been achieved.Synthesis was conducted at hydrothermal conditions (80
C) by the use of alkaline silicates (NaxSiyOz)
and alkaline aluminates (NaxAlyOz).Chemical treatments were made on ‘‘Tripoli’’ rocks (mainly constituted by opaline silica) coming
from Crotone Basin (southern Italy) in order to obtain Na2 SiO3 ÆnH2O.Volcanic pyroclastic rocks (naturally zeolitised to chabazite
and phillipsite) from the Vico Administrative Province (central Italy) were treated to obtain the NaAlO2 solution.
Both products were mixed to gain the gel NaAlSixOy ÆnH2O necessary for the zeolitic synthesis.
Mineralogical–crystallographical–chemical and textural–physical characterisation showed that Na–X zeolite synthesis begins
after 5 h and reaches its crystallisation climax at 18 h, with a broad field of existence (about 500 h) of the Na–X phase.Then
Na–X is substituted by HS (Hydroxysodalite) zeolite.The characterisation shows that microtextural (scanning electron microscope
images) and crystallographic values as well as other physical properties (specific surface, density) are comparable to the reputed ones
for commercial zeolite.The thermal behaviour (TG-DTA) and IR response also provide consistent evidence of good achievement of
Na–X zeolite synthesis.Finally, the wide (in terms of time) range of stability of Na–X zeolite seems to allow trans
fer to an industrial production scale.

Flyash, an industrial by-product, rich in silica and alumina contents, has been known to be a useful material for synthesizing zeolites. These zeolites are minerals of alumino silicate group and exhibit high affinity to accommodate and exchange one or a group of metallic cations and/or water molecules. Though, zeolites find several industrial applications of high commercial and environmental values, their synthesis, characterization and recommendations for the most appropriate application are challenging tasks. This is mainly due to the fact that ash zeolites can be synthesized by employing different synthesis methods (viz., hydrothermal, fusion, microwave assisted hydrothermal and molten salt method) and several factors (viz., concentration of alkali source, temperature, time of reaction, liquid/solid ratio and type of flyash), which can significantly affect their overall properties. As such, a critical review of these methods and their limitations and superiority over each other becomes necessary. Incidentally, it has also been demonstrated by the researchers that there are several industrial applications for these fly ash zeolites and selection of a particular type of the zeolite would depend on its basic properties (viz., pore volume, crystal structure, Si/Al ratio and ion exchange characteristics). Hence, review of various industrial applications of zeolites and a critical commentary on the methodologies employed for zeolite selection also becomes important. As such, efforts have been made in this paper to address these issues in detail.

A B S T R A C T Hydrosodalites are a family of zeolitic materials which have a diverse range of possible applications such as water desalination. Typical synthesis methods are relatively complex, using hydrothermal production and pre-processing and it is desirable to use lower energy and more cost-effective processing routes. For the first time, a low temperature, non-hydrothermal synthesis procedure for hydrosodalites, compatible with extrusion processing , is demonstrated. Kaolinite precursor, without calcination, was activated with a sodium hydroxide solution and formed at a workability consistent with extrusion. The cured samples were characterised using a range of advanced analytical techniques including PXRD, SEM, TGA, 27Al and 29Si-MAS-NMR, and FTIR to confirm and quantify conversion of the precursor to product phases. The synthesis consistently formed a 8:2:2 basic hy-droxysodalite phase and the reaction was shown to follow a largely linear relationship with Na:Al until full conversion to the hydrosodalite phase was approached. The hydrosodalite became more ordered for Na:Al ≥ 1. There is good agreement between quantitative measurements made using PXRD, TGA and 29Si-MAS-NMR methods, providing confidence in the results. It has been shown that it is possible to synthesise hydrosodalite materials in a consistent and predictable manner, using non-hydrothermal methods, at the viscosity used for extrusion processing. This novel processing route could reduce production costs, production impacts and open up new applications for this important family of materials.

Synthetic zeolite Na-A was prepared from Egyptian kaolinite by hydrothermal treatment to be used as an adsorbent for removal of phosphate from aqueous solutions. The present work deals with the application of response surface methodology (RSM) and central composite rotatable design (CCRD) for modeling and optimization of the effect of four operating variables on the removal of phosphate from aqueous solution using zeolite Na-A. The parameters were contact time (0.5 -6 h), phosphate anion concentrations (10 -30 mg/L), adsorbent dosage (0.05 -0.1 g), and solution pH (2 -7). A total of 26 tests were conducted using the synthetic zeolite Na-A according to the conditions predicted by the statistical design. In order to optimize removal of phosphate by synthetic zeolite Na-A, mathematical equations of quadratic polynomial model were derived from Design Expert Software (Version 6.0.5). Such equations are second-order response functions which represent the amount of phosphate adsorbed (mg/g) and the removal efficiency (%) and are expressed as functions of the selected operating parameters. Predicted values were found to be in good agreement and correlation with experimental results (R 2 values of 0.918 and 0.905 for amount of phosphate adsorbed and removal efficiency of it, respectively). To understand the effect of the four variables for optimal removal of phosphate using zeolite Na-A, the models were presented as cube and 3-D response surface graphs. RSM and CCRD could efficiently be applied for the modeling of removing of phosphate from aqueous solution using zeolite Na-A and it is efficient way for obtaining information in a short time and with the fewer number of experiments.

Large single crystals of zeolite Y with diameters up to 210-245 mm and Si/Al=1.71 have been synthesized from a reaction mixture (4.76Na 2 O : 1.0Al 2 O 3 : 3.5SiO 2 : 454H 2 O : 0.6T 2 O : 5TEA) comprising fumed silica (Cab-O-Sil M5), sodium aluminate, and the template bis(2-hydroxyethyl)dimethylammonium chloride (TCl) in an aqueous triethanolamine (TEA) cosolvent. #

Mordenite is a zeolite that has been used as a selective adsorbent and as a catalyst. Mordenite zeolite with crystal diameter 65 nm and crystal length 7 lm was successively synthesized in the absence of organic template by hydrothermal method at 180 °C for 5 days after stirring at high speed and aging in the synthesis mixture with the molar composition of 12Na 2 O:100SiO 2 :2Al 2 O 3 :500H 2 O. The produced samples were investigated using XRD, SEM, FT-IR, EDS, DTA/TG and BET surface area. The prepared sample , crystallized in needle shape crystals. Total (BET) surface area was 52.14 m 2 /g whereas, total pore volume was 0.2 cm 3 /g. Average pore diameter was 24.16 Å. Thermogravimetry analysis (DTA/TG) showed that, at room temperature to 800 °C, mordenite mass loss is 6%.

This study was aimed at optimizing the synthesis conditions for pure phase zeolite Na-P1 from three coal fly ashes obtained from power stations in the Mpumalanga province of South Africa. Synthesis variables evaluated were: hydrothermal treatment time (12–48 hours), temperature (100–160°C) and varying molar quantities of water during the hydrothermal treatment step (H2O:SiO2 molar ratio ranged between 0–0.49). The optimum synthesis conditions for preparing pure phase zeolite Na-P1 were achieved when the molar regime was 1 SiO2: 0.36 Al2O3: 0.59 NaOH: 0.49 H2O and ageing was done at 47°C for 48 hours. The optimum hydrothermal treatment time and temperature was 48 hours and 140°C, respectively. Fly ashes sourced from two coal-fired power plants (A, B) were found to produce nearly same high purity zeolite Na-P1 under identical conditions whereas the third fly ash (C) lead to a low quality zeolite Na-P1 under these conditions. The cation exchange capacity for the high pure phase was found to be 4.11 meq/g. These results highlight the fact that adjustment of reactant composition and presynthesis or synthesis parameters, improved quality of zeolite Na-P1 can be achieved and hence an improved potential for application of zeolites prepared from coal fly ash.

This study investigates the feasibility of using synthetic zeolite Na A-X blend prepared from fly ash as near surface disposal backfill material. Tests were conducted at laboratory scale to evaluate the physical and chemical properties of the prepared zeolite. The zeolite density, porosity, and particle size distribution were measured. The distribution coefficient (Kd) value of Cs ions was evaluated using batch sorption experiment in synthetic groundwater to simulate possible conditions for near surface disposal. The transient behavior of the batch sorption experimental data were analyzed using Lagergren, Ho and Mckay, and Morris–Weber rate models to assess the controlling mechanism of the sorption process. It was found that the sorption process is chemisorption and controlled by diffusion mechanism. The dispersional behavior of Cs ions on the prepared material was studied using column experiment and the hydrodynamic dispersion coefficient was determined. To provide an overall functional performance of the proposed backfill material, the long-term behavior of the prepared zeolite has been evaluated using computer model. This model consists of two modules that has been developed to study the migration of Cs radionuclides from bare cementitious waste form through the backfill. The study compares the release rate from bentonite–crushed rock mixture to that from the prepared zeolite. The result demonstrates that synthetic zeolite Na A-X blend shows a better performance in terms of radionuclide containment.

Abstract  Sludge from a treatment water Brazilian plant station is, frequently, disposed and launched directly in
the water bodies, causing a negative impact in the environment. Also, fly ash is produced by burning of coal in coalfired
power
stations
and
is
the
industrial
solid
waste
most
generated
in
southern
Brazil:
approximately
4
million

tons/y.
An
efficient
disposal
of
coal
fly
ash
is
an
issue
due
to
its
massive
volume
and
harmful
risks
to
the

environment.
The
main
purpose
of
this
study
was
to
evaluate
the
technical
possibilities
of
incorporating
cyclone
fly

ash
(CFA)
and
sludge
from
a
waste
water
treatment
plant
(SWTP)
in
the
production
of
ecological
bricks.
The
wastes

were
analyzed
for
physico-chemical,
mineralogical
and
morphological
properties.
Various
mixtures
were
prepared

by
incorporating
these
industrial
wastes
in
brick
production.
The
effects
of
wastes
incorporation
on
physical

properties such as compressive strength and water absorption have been determined. The best result, in terms of
compression strength and water absorption, was reached by the series of bricks produced with 60 % soil, 12 %
cement, 8 % coal fly ash and 20 % SWTP by weight. The results showed that SWTP and CFA presented a potential
to be used as waste additives in the production of soil-cement bricks

Salinity stress is a severe environmental stress that affects plant growth and productivity of potato, a strategic crop moderately sensitive to saline soils. Limited studies are available on the use of combined nano-micronutrients to ameliorate salinity stress in potato plants (Solanum tuberosum L.). Two open field experiments were conducted in salt-affected sandy soil to investigate plant growth, physiology, and yield of potato in response to soil salinity stress under single or combined application of Zn, B, Si, and Zeolite nanoparticles. It was hypothesized that soil application of nanoparticles enhanced plant growth and yield by alleviating the adverse impact of soil salinity. In general, all the nano-treatments applications significantly increased plant height, shoot dry weight, number of stems per plant, leaf relative water content, leaf photosynthetic rate, leaf stomatal conductance, chlorophyll content, and tuber yield, as compared to the untreated control. Furthermore, soil application of these treatments increased the concentration of nutrients (N, P, K, Ca, Zn, and B) in plant tissues, leaf proline, and leaf gibberellic acid hormone (GA3) in addition to contents of protein, carbohydrates, and antioxidant enzymes (polyphenol oxidase (PPO) and peroxidase (POD) in tubers. Compared to other treatments, the combined application of nanoparticles showed the highest plant growth, physiological parameters, endogenous elements (N, P, K, Ca, Zn, and B) and the lowest concentration of leaf abscisic acid (ABA) and transpiration rate. The present findings suggest that soil addition of the aforementioned nanoparticles can be a promising approach to improving crop productivity in salt-affected soils.

In this work, several variables that can affect the adsorption of Ni(II) using NH 2-SBA-15 were studied in a batch adsorption system including; pH (1-6), contact time (0-150 min), initial concentration (20-120 mg L-1), NH 2-SBA-15 dose (0.025-0.3 g) and temperature (293-333 K). The removal percentage increased with increasing the pH, the contact time, NH 2-SBA-15 dose and temperature, while the increase of the initial concentrations for this metal ion reduced their percentage removal. It appeared that the Langmuir adsorption isotherm model had the best fit with R 2 = 0.99, and the maximum capacity of monolayer adsorption increased from 64.52 to 90.1 mg g-1 as increasing in the temperature from 293 to 333 K, respectively. It was demonstrated that the kinetic studies were fitted well with the pseudo-second-order kinetic model (R 2 = 0.99). The results of thermodynamic parameters showed that the process is endothermic chemisorption (ΔH° = 93.8734 kJ mol-1) with a very little degree of disorder (ΔS° = 0.38812 kJ mol-1 K-1) and whenever the temperature increased from 293 to 333 K, the process became more spontaneous (ΔG° =-19.098 to-34.33 kJ mol-1 K-1).

In this study, we prepared hydrated and dehydrated Na-zeolites under different conditions using sodium hydroxide (NaOH) and Egyptian kaolin. The synthetic zeolites were characterized by XRD, SEM, specific surface area and their adsorption behavior in the uptake of Cu 2+ ions from aqueous solution were investigated, in order to compare the obtained results. The dehydrated Na-A zeolite showed well developed crystals and high surface area compared to hydrate Na-A zeolite. Batch adsorption studies showed that the maximum Cu 2+ uptake percentage of dehydrated Na-A zeolite (94%) has been recorded after 5 min of contact time. On the other hand, the removal percentage of hydrated Na-A zeolite was 75% after 5 min reaching its maximum uptake percentage (97%) after 120 min. The mechanism of cooper ions uptake by dehydrated Na-A zeolite followed ion exchange and precipitation while ion exchange was the main mechanism of adsorption in the case of hydrated Na-A zeolite. Copper adsorption kinetics by the synthetic Na-A zeolites was well fitted by pseudo-second-order kinetic model with R 2 greater than 0.99. Equilibrium sorption isotherms of Cu 2+ ions by the synthetic zeolites were explained using the Langmuir and Freundlich isotherms models.

The fly ash disposal at thermal power plants is either through wet-or dry-disposal systems. As these disposal practices result in different characteristics for the fly ashes, their interaction with alkalis, and hence the zeolitization potential, will be different. In order to demonstrate this, investigations were conducted to study the physical, chemical, mineralogical and morphological characteristics of the residues of the fly ashes collected from the lagoons and hoppers of the same thermal power plant, after their hydrothermal treatment. Field-emission-gun scanning electron microscopy and X-ray diffraction analysis of these residues demonstrated that the hopper ash attains an exceptionally high cation-exchange capacity and SiO 2 / Al 2 O 3 ratios (SAR), which correspond to the formation of major fly ash zeolites as compared to its counterpart. In other words, the study presented here helps to establish the superiority of hopper ash over lagoon ash for synthesizing fly ash zeolites and their enhanced quantity and quality.

Transformation of metakaolinite to basic sodalite
[Na4(AlSiO4)3Cl]2 in the presence of NaCl was investigated.
Experimental synthesis was performed in alumina
crucibles at 850°C and ambient pressure. Reaction progress
was monitored by X-ray powder diffraction from 1h to
400h. During the crystallization of sodalite, the presence
of reacting residual halite was testified throughout the run
synthesis; intermediate-phase carnegieite was detected in
the initial stage of the synthesis run (1h-24h). Both sodalite
and residual halite were evidenced between 24 and 101h,
where sodalite reaches a climax in the crystallization degree.
Progressive replacement of sodalite by nepheline was
testified starting from 171h. Synthesized sodalite was submitted
to chemical-crystallographical and mineralogicaltextural
studies and Infra-Red Spectrometry (IR), providing
values comparable to the ones available in the literature on
this mineral. A continuous loss in weigth of the NaCl plus
metakaolinite starting matrix contained in the alumina
crucible heated in oven was testified and attributed to Cl
vaporization. An analytical mathematical model to solve the
parabolic differential equation related to the chlorine diffusion
processes occurring within the crucible is proposed.
Experimental data and numerical results, when compared,
although satisfactory, suggest the necessity of some modelling
improvements.

H-ZSM-5 materials embedded in an amorphous silica were successfully synthesized with three different Si/Al ratios (i.e., 40, 45, and 50). The presence of the MFI structure in the synthesized samples was confirmed by X-ray diffraction (XRD), Fourier transform infra-red (FT-IR), and solid state-nuclear magnetic resonance (SSNMR) techniques. The morphology and textural properties of the samples were investigated by scanning electron microscopy (SEM), TEM, and N 2-physisorption measurements. Furthermore, acidic properties of the synthesized catalysts have been studied by NH 3-TPD and FT-IR spectroscopy of CO adsorption studies. Variation of the Si/Al ratio affected the crystal morphology, porosity, and particle size, as well as the strength and distribution of acid sites. The synthesized zeolite materials possessed low acid-site density and exhibited high catalytic activity in the methanol-to-olefin (MTO) reaction. To study the intermediate species responsible for catalyst deactivation, the MTO reaction was carried out at high temperature (500 • C) to accelerate catalyst deactivation. Interestingly, the synthesized catalysts offered high selectivity towards the formation of propylene (C 3=), in comparison to a commercial microporous crystalline H-ZSM-5 with Si/Al = 40, under the same reaction conditions. The synthesized H-ZSM-5 materials offered a selectivity ratio of C 3= /C 2= 12, while it is around 2 for the commercial H-ZSM-5 sample. The formation of hydrocarbon species during MTO reaction over zeolite samples has been systematically studied with operando UV-vis spectroscopy and online gas chromatography. It is proposed that the strength and type of acid sites of catalyst play a role in propylene selectivity as well as the fast growing of active intermediate species. The effective conversion of methanol into propylene in the case of synthesized H-ZSM-5 materials was observed due to possession of weak acid sites. This effect is more pronounced in H-ZSM-5 sample with a Si/Al ratio of 45.

Aluminum sources have a great effect on ZSM-5 crystallization which leads to change in the properties of the final product. The crystallinity of nanosized ZSM-5 zeolite from precursor's mixtures containing different aluminum sources as sodium aluminate, aluminum chloride and aluminum nitrate has been studied. The produced samples were investigated using XRD, SEM, FT-IR, EDS and BET surface area. The average crystal size increased in the order; sodium aluminate <aluminum nitrate < aluminum chloride, whereas surface area increased as aluminum chloride < aluminum nitrate < sodium aluminate.

In this study, the possibility of optimizing the use of fertilizers on Ranunculus asiaticus by adding chabazite with Plant Growth Promoting Rhizobacteria (PGPR) to the substrate was evaluated. The five experimental groups in cultivation were: i) group without zeolites (CTRL), irrigated with water and substrate previously fertilized; ii) group with natural chabazite (CN) and 100% fertilised substrate; iii) group with chabazite enriched with PGPR (CM) and 100% fertilised substrate; iv) group with natural chabazite (CN2) and 50% fertilised substrate; v) group with chabazite enriched with PGPR (CM2) and 50% fertilised substrate. All plants treated with chabazite (CN and CN2) and chabazite enriched with PGPR (CM and CM2) showed a significant increase in the agronomic characteristics analysed compared to the untreated control (CTRL). The results show that the microorganisms are able to improve the performance of zeolitite, probably increasing the efficiency of nutrient and water absorption by the roots. This is also evident when evaluating physiological parameters where the photosynthesis rate and chlorophyll content are significantly better in (CM) and (CM2) than in (CN) and (CN2). Zeolites can act as a "home" for microorganisms, as is normally the case in nature with clays. In fact, under conditions of water stress, microorganisms take refuge inside the clay particles until the environmental conditions are suitable again to colonize the soil. Zeolites are able to actively interact with the organic components present in the soil or brought with fertilization, and have the ability to make more available the mineral and nutritional components present within their crystalline lattice, according to the needs of the plant.

Clinoptilolite, a common natural zeolite was chemically modified with HCl and Si to enable the sequestration of Cs and Sr isotopes, in both water and some types of solid waste (nuclear industry residues, for instance). The method reported allows to preserve the crystalline structure of the zeolite, thus maintaining its advantageous textural characteristics, while incorporating the adequate surface moieties for various applications, including trapping of polluting ions in water.

Las zeolitas son aluminosilicatos de estructura de armazón y constituyen rocas frescas provenientes de las transformaciones de los vidrios volcánicos. En Cuba existen diferentes manifestaciones zeolíticas de importancia, entre ellas, la del yacimiento “Tasajeras”, en las provincias centrales del país. La falta de feldes-patos de adecuada calidad para la industria del vidrio ha servido de estímulo a la realización de este trabajo. El curso de las reacciones de formación de silicatos se siguen mediante estudios térmicos comparativos entre un vidrio tradicional con feldespato y otro con zeolita, discutiéndose posteriormente sus particularidades. Las especificidades del comportamiento físico–químico de las mezclas vitrificables permiten inferir mejoras en los procesos de elaboración del vidrio y ahorros energéticos sensibles durante el proceso industrial.

PACS: 81.05.Kf

The local vegetable oils (Coconut and Palm Kernel Oils) are usually faced with short shelf-life which has been associated with the presence of some unwanted materials present in them. This study explores the potential of using locally manufactured Zeolites in removing these impurities to improve the shelf life of these oils. The Zeolite used in this study was synthesized using locally available raw materials such as bauxite and kaolin through the hydrothermal process.  X-ray diffraction studies of the synthesized Zeolite were found to be part of the ZSM-11 Zeolite type group. FTIR analysis of the sample showed a weak vibrational peak at 1642cm-1 and a strong band at 987cm-1. Batch process for the removal of these unwanted materials was performed. Percentage reduction of 85.71%, 89.22%, 89.36% and 83.81% was recorded for impurities, moisture content, free fatty acid and peroxide value reduction in Palm Kernel Oil and 85.71%, 83.33%, 93.26%, 90.57% for Coconut Oil. Kinetic studies showed the process favoured the Pseudo-first order with R 2 of 0.956 and 0.971 for Coconut and Palm Kernel Oil respectively for impurities The plot of (t / q e) vs. t exhibits a very high linearity and can be concluded that the adsorption rate of the moisture Original Research Article Anang et al.; CSIJ, 28(4): 1-13, 2019; Article no.CSIJ.53720 2 content, impurities, FFA and peroxide value is dependent on the adsorbate used and contact time. The final oils had very good physicochemical parameters with improved qualities. It can be concluded that the synthesized Zeolite was effective for the refining of locally produced Coconut and Palm Kernel Oils and can be accessed for commercial applications.

The amount of fly ash generated has been increasing at an alarming rate throughout the world. It is the finely divided mineral residue resulting from the combustion of coal in thermal power plants. It consists of inorganic, incombustible matter that has been fused during combustion into a glassy, amorphous structure. The typical thermal power plant will burn pulverized coal in a furnace with a boiler. The combustion products include fly ash, bottom ash and a boiler slag and flue gas desulfurization (FGD) materials, which creates serious danger if released into environment. This has attracted more attention within a context of progressively more stringent regulation of hazardous air pollutants (viz. fly ash) discharge from thermal power station. The disposal of such a huge quantity has become a pressing issue. Several approaches have been made for proper utilization of fly ash, either to reduce the cost of disposal or to minimize the environmental impact. This study presents the wide variety of utilization of this industrial byproduct - fly ash and its application in the field of an environment. One of the major ways out is the conversion of fly ash to zeolites, which has wide applications in the field of an environment.

Samp les of crystalline alu minosilicate, the granules of which are crystalline aggregates of zeo lite X with different degrees of exchange of cations Na + for cations Ca 2+ , Mg 2+ , К + or Н + were synthesized. Based on obtained samples, the adsorption of Н 2 О, СО 2 , С 6 Н 6 and n-С 7 Н 16 in static and dynamic modes is studied. The dependencies of the amount of adsorbed substance on the type and content of exchangeable cations in zeolite X were found.

Coal fly ash (CFA) is a waste product produced from the electrical power plant and hazardous towards the environment. However, the high composition of silica and alumina in the CFA makes it useful as raw materials in the zeolite synthesis. However, the presence of silica in the form of quartz in the CFA does not facilitate the transformation of CFA to zeolite at 100oC and autogeneous pressure. In this study, CFA was converted to zeolites in various NaOH concentrations by microwave heating at various heating time. All synthesized product were characterized by X-ray diffraction(XRD), and gravimetric analysis. XRD has shown that quite pure sodalite in nanosize has been formed as early as 15 minutes and increase with time. Prolong heating up to 45 minutes has reduced the content of quartz to ca 20%. Gravimetric analysis performed on the liquor of the reaction showed that the dissolved silica decrease with increase of heating time indicating that most of the dissolved quartz is used up to form sodalite framework. Hence, quartz of CFA did help in enhancing the crystallinity of the formed sodalite after prolong heating.

In this work, it is shown that based on powder zeolite type Y, mono metallic and bimetallic catalysts have been developed that are promising for petroleum chemistry processes. The method is based on the preparing hydrogen form of Y zeolite by ion exchange with a solution of ammonium nitrate at a starting concentration of 70 g.l-1 and nickel nitrate solution which provides Ni cations. Then after preparation of bimetallic catalysts by impregnating second metal by incipient wetness. All samples and catalysts were characterized using X-ray diffraction (XRD) analysis techniques, adsorption methods, and elemental analysis. The research results showed that in order to reach the degree of exchange of Na + for H + cations no less than 0.73, it is necessary to carry out four exchanges of Na + by NH4 + and three intermediate thermal treatments at 540 °C for 3 to 4 hours in air atmosphere.

The importance of porous materials with very small crystal diameter is immensely increased
because of their large range of applications in our daily life. Mordenite falls in the category
which is a microporous, synthetic zeolite with an ideal unit cell composition of Na8. (AlO2)8.
(SiO2)40. nH2O or Na8Al8Si40O96.nH2O and a lot of work is going on its synthesis according to
its application.
But we have mainly focused on Mordenite synthesis in nanosize without adding seed and
incorporating its effect on Mordenite morphology by comparing with standard Mordenite.
Synthesis of Mordenite nanocrystals was mainly divided into three steps. The first step covered
the procedure for preparation of gel without adding seed. The gel is then converted into raw
Mordenite under hydrothermal conditions in the second step. Finally, in third step raw Mordenite
product is recovered into pure Mordenite crystals by applying washing with distilled water and
drying techniques. The effect of sans adding seed and distilled water in the sample is then
studied with the help of X-ray diffraction (XRD) and scanning electron microscopy (SEM).
Vast range of laboratorial and industrial applications of Mordenite are summarized into three
major uses. These includes the use of Mordenite as a catalyst, as an adsorbent and as an ion
exchanging sieve. Other uses of Mordenite are also discussed.

The importance of developing clean and cheap water purification systems is critical to maintaining life. Transporting clean water to the International Space Station (ISS) is problematic due to the prohibitive cost and high degree of difficulty. The current water purification system in place produces an extremely acidic urine brine. In the future, membrane technologies could recover much of the water in the brine. Zeolites are a potential candidate for usage in these membranes. However, corrosion of the zeolites over long periods of exposure to the urine brine would limit the effectiveness of the membranes. The purpose of this experiment was to investigate Zeolite Socony Mobil - 5 (ZSM-5) for application in water treatment membranes. The zeolites were added to four acids found in the urine brine generated on the ISS (chromic acid, potassium phosphate, sodium phosphate, and sulfuric acid) and a water control. Samples of the zeolites were removed on regular time intervals up to 21 days. Data from a variety of characterization methods was then analyzed for any damage or change in structure of the zeolites caused by exposure to acid. No substantial damage was observed after 21 days of immersion in acidic brine samples. These results suggest that ZSM-5 type zeolites would be ideal for application in water purification membranes. Furthermore, similar purification membranes can be incorporated into other water purification systems such as the ones found internationally, especially those places that are constantly plagued by droughts.