Evaluation Of Zeolite Research Articles

Evaluation of zeolite as supplementary cementing material

The current paper researches the impacts of including zeolite in M30 grade of concrete mix as a plausible type of pozzolanic material. Pozzolans comprise of incredibly fine particles of siliceous and aluminous based materials. They rarely possess little or no binding ascribes, but in the presence of water, they respond with calcium hydroxide to create cementing compounds. Zeolite is one among the natural pozzolanic materials which has been successfully utilized to supplant the cement content fractionally in preparation of mortar or concrete elements. The objective of this experimentation is to replace cement content with zeolite which is accessible in the vicinity, and to concentrate on its impact on the mechanical properties of concrete. The construction industry has been hit hard with skyrocketing prices and severe shortage of natural river sand across many parts of the nation. Hence an attempt is also made to utilize manufactured sand instead of natural river sand. The incorporation of zeolite up to the degree of 15% resulted in an optimum magnitude of mechanical strengths of the concrete blend.

Environmental Applications of Zeolites: Hydrophobic Sn-BEA as a Selective Gas Sensor for Exhaust Fumes

Environmental monitoring of pollutants, such as NOx and COx, which can be facilitated by a range of gas sensors, is of considerable fundamental and practical importance. This work has been focused on the synthesis and evaluation of zeolite β with tin (Sn-BEA) and dealuminated β (DeAl-BEA) zeolites. The zeolite samples have been extensively investigated by IR, UV-VIS and NMR spectroscopy, XRD, TGA, and N2 adsorption-desorption. The prepared Sn-BEA sample is characterised by the submicron particle size, an almost defect-free structure, and high hydrophobicity. Sensors containing selective microporous layers based on Sn-BEA and DeAl-BEA zeolites have been prepared and extensively tested. Both the Sn-BEA and DeAl-BEA zeolites have been deposited in thin films and evaluated as gas sensors for CO, CO2, NO, and NO2 in the presence of water vapour at room temperature. The Sn-BEA zeolite-based sensor showed high selectivity towards NO2, while the DeAl-BEA is selective towards CO2 and NO2.

Effect and Evaluation of Zeolite and Biohumus on Biological Indicators of Irrigated Seed-gray Soils

The effect of zeolite and biohumus on the biological activity of irrigated grass-gray soils under beans of the subtropical zone was studied. It was determined that the biological activity of the irrigated grass-gray soils changes depending on the growth phase of the bean, the applied biohumus and zeolite rate. Based on complex biological indicators (activity of enzymes, the number of microorganisms, abundance of carbon dioxide released from the soil, intensity of the nitrification process, intensity of decomposition of cellulose), bio-diagnostics of irrigated meadow-gray soils were given, an integral indicator of the biological condition of the soil was determined, and a biological assessment was carried out.
 The purpose of the work is to determine the effect of biohumus and zeolite on the biological activity of irrigated grass-gray soils used under the bean plant, and to conduct a biological evaluation based on complex biological indicators.
 The research object is irrigated meadow-gray soils (in WRB - Irragic Calsisols) of the subtropical zone, various doses of biohumus and zeolite, small bean-mung bean (Vigna Angularis) plant. Scheme of the experiment: 1. control (without fertilizer); 2. biohumus 5 t/ha; 3. zeolite 5 t/ha (clinoptilolite); 4. biohumus 5 t/ha + zeolite 5 t/ha; 5. biohumus 7.5 t/ha; 6. zeolite 7.5 t/ha; 4. biohumus 7.5 t/ha + zeolite 7.5 t/ha.
 Chemical composition of zeolite: Na2O-0.55; MgO-1.49; Al2O3-11.86; SiO2-66,0; P2O5-0.11; SO3-0.01; K2O -9.02; CaO-6.61; TiO2-0.51%; MnO-0.07; Fe2O3-3.77.
 Chemical composition of biohumus: humus 16%, pH 7, total azot (N) 3.2%, total phosphorus (P) 2.6%, total potassium (K) 2%, Ca 4.3%, Mg 0.6%, Fe 0.45%, Cu 0.5%, C:N 13.
 Mathematical-statistical calculation of the numbers obtained as a result of the research was carried out based on the Anova programma. The obtained results show a significant difference between the variants and compared to the control.

Evaluation of zeolite, nanomagnetite, and nanomagnetite-zeolite composite materials as arsenic (V) adsorbents in hydroponic tomato cultures

There is a growing interest in the use of adsorbent nanoparticles to mitigate the toxic effects of pollutants in natural matrices. However, due to their small size, nanoparticles have the potential to transport and disseminate contaminants adsorbed on their surfaces into environmental compartments with greater risk to human, animal, or plant health. This potential consequence of nanoparticle application remains largely unstudied. Here, we studied the application of three adsorbents, including zeolite (Z, micrometric size), nanomagnetite (Mt), and a nanomagnetite-zeolite composite (MtZ) intended to mediate arsenic toxicity in hydroponic tomato cultures. Adsorption studies showed an arsenate adsorption sequence of MtZ (6.2 mg g−1) ≥ Mt (4.7 mg g−1) ≫ Z (0.3 mg g−1). Tomatoes grown under the Mt condition demonstrated the lowest growth rate (4.2 cm), corresponding to a 45% decrease compared to the control (7.6 cm), as well as the highest oxidative stress level (0.024 μmol g−1) as indicated by malondialdehyde (MDA) concentration, almost twice the control (0.014 μg g−1). Tomatoes grown under MtZ conditions showed a 22% decreased growth (5.9 cm) but MDA levels (0.012 μmol g−1) were comparable to the control. Together, these results suggest that Mt at the nanometric size could obstruct channels in the plant and prevent absorption of water and nutrients. Anchoring nanomaterials in larger composites of micrometer size presents a promising alternative that would retain their super-adsorbent properties while avoiding toxicity due to nanometric size.

Evaluation of Zeolite as a Potential Reactive Medium in a Permeable Reactive Barrier (PRB): Batch and Column Studies

The purpose of this work is to evaluate the capacity of a natural zeolite to be used as a reactive material in a permeable reactive barrier (PRB) to remove inorganic contaminants from groundwater. To this aim, zeolite samples were subjected to characterization tests, column experiments, batch tests and a flushing process to evaluate the adsorption and desorption capacities of the zeolite. In the column experiments, the samples were subjected to eight successive cycles involving the percolation of a potassium aqueous solution (1500 mg/L) and a subsequent flushing process with water. Batch tests were conducted by mixing 20 g of zeolite with 100 mL of single-element aqueous solutions of K and Zn with concentrations of 200 mg/L. The results indicate that the zeolite rock is composed predominantly of clinoptilolite species and has a Si/Al ratio of 6.8, a high cationic exchange capacity (CEC) of 180 cmolc/kg and a high K+ adsorption rate with a removal efficiency of 78%. The adsorption isotherms of the zeolite follow the Langmuir model and are well fit by a pseudo-second-order kinetic model showing a high correlation coefficient (r2 > 0.999) for both K+ and Zn2+ cations. Additionally, the contaminant transport parameters for K+ ions (Rd = 24.9; Dh = 1.32 × 10–2 cm2/s and α = 1.42) reveal that the zeolite is resistant to the dispersion of ions in the barrier, indicating that the material has advantageous characteristics for use in a PRB. However, the flushing process of the material is not efficient, indicating that the appropriate use of the zeolite is in clean-up systems in which the adsorbent material can be exchanged after losing its efficiency as a reactive barrier.

Characterization and Evaluation of Zeolite A/Fe3O4Nanocomposite as a Potential Adsorbent for Removal of Organic Molecules from Wastewater

In this work, zeolite (Z) and Z-Fe3O4nanocomposite (Z-Fe3O4NC) have been synthesized. The Fe3O4nanoparticles were synthesized using the extract from maize leaves and ferric and ferrous chloride salts and encapsulated into the zeolite framework. The nanocomposite (Z-Fe3O4NC) was characterized using X-ray diffractometer (XRD), Fourier-transform infrared (FT-IR) spectroscopy, energy-dispersive X-ray (EDX) spectroscopy, and scanning electron microscopy (SEM). The potential of Z-Fe3O4NC as an adsorbent for removing methylene blue molecules (MB) from solution was examined using UV-Vis and kinetic and equilibrium isotherm models. The adsorption data fitted best with the pseudo-second-order model and Weber and Morris model, indicating that the adsorption process was chemisorption, while the Weber and Morris described the rate-controlling steps. The intraparticle diffusion model suggests that the adsorption processes were pore and surface diffusion controlled. The Langmuir isotherm model best describes the adsorption process indicating homogeneous monolayer coverage of MB molecules onto the surface of the Z-Fe3O4NC. The maximum Langmuir adsorption capacity was 2.57 mg/g at 25°C. The maximum adsorption efficiency was 97.5%. After regeneration, the maximum adsorption efficiency achieved at a pH of 7 was 82.6%.

Evaluation of zeolite supported bimetallic nanoparticles of zero-valent iron and copper (Z-nZVI/Cu) in the presence of ultrasonic for simultaneous removal of nitrate and total coliforms from aqueous solutions: optimization and modeling with response surface methodology

In this study, the removal of nitrate and total coliforms by zeolite-supported bimetallic nanoparticles of zero-valent iron and copper (Z-nZVI/Cu) coupled with ultrasonic treatment was studied. The Z-nZVI/Cu catalyst was synthesized by ion exchange method and was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results of analyzes were indicative of the appropriate synthesis of catalyst and high distribution of iron and copper nanoparticles on zeolite. The effects of different operating parameters such as initial pH, catalyst concentration, initial concentration of pollutants, and catalyst concentration on removal of nitrate and total coliforms were investigated. The results showed that nitrate removal efficiency decreased with increasing pH and initial concentration of nitrate, while it increased by increasing the concentration of catalyst and ultrasonic frequency. To eliminate total coliform, the same trend was observed, except for increasing the removal efficiency by increasing the total coliform concentration. The results of optimization by response surface methodology (RSM) show that the maximum removal efficiency of nitrate and coliform were 97.77 and 97.77%, respectively. The results of the comparative experiments between the various processes showed that the ultrasonic process alone and ultrasonic coupled with Z-nZVI/Cu catalyst are suitable to provide the highest removal of total Coliforms and nitrate from aqueous solutions, respectively.

The anticorrosive performance of cost saving zeolites

PurposeIn recent years, zeolites have been highlighted as a new component in many industrial applications owing to their unique properties. The purpose of this study is to apply three prepared types of zeolites Na-X, Na-Y and hydroxysodalite (Na-HS) in anticorrosive paint formulations to be evaluated as a partial replacement to zinc phosphate in anticorrosive paint formulations to protect carbon steel.Design/methodology/approachThe three types of zeolites were characterized using different instrumental analysis such as X-ray diffraction, scanning electron microscopy and X-ray fluorescence. Evaluation of zeolites was done using American society for material and testing. Then, they were incorporated in paint formulations based on medium oil-modified soya-bean dehydrated castor oil alkyd resin in the presence and absence of zinc phosphate. Their corrosion behavior was estimated using both immersion test and electrochemical impedance measurements in 3.5% NaCl.FindingsGenerally, the prepared zeolites exhibited good corrosion protection performance, but in presence of zinc phosphate the performance was better. This proves that, zeolites by themselves can resist corrosion but not efficiently, while in presence of zinc phosphate and owing to a synergistic effect between them, the performance was better. This opens the way to partial replacement of zinc phosphate with another safer and cheaper ingredient, which is zeolite.Practical implicationsThe three zeolites can be applied in many industries besides the paint industry, such as reinforcing filler in rubber, plastics and ceramic composites, also can be applied in paper filling, paper coatings and electrical insulation.Originality/valueThe three zeolites are environmentally friendly materials that can partially replace other expensive anticorrosive pigments (e.g. zinc phosphate).

Synthesis and evaluation of zeolite surface-modified perlite

Synthesis and evaluation of zeolite surface-modified perlite

Development and Evaluation of Zeolites and Metal–Organic Frameworks for Carbon Dioxide Separation and Capture

AbstractWith increasing carbon dioxide (CO2) emissions from the combustion of fossil‐based fuels, the concentration of CO2 in the atmosphere is growing at 407.54 parts per million, as released in May 2016. Accordingly, the reduction of CO2 emissions is an essential issue for global climate changes. Tremendous efforts have been directed towards the goal of CO2 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 CO2. Hence, this comprehensive review focuses on studying and analyzing newly developed methods to reduce greenhouse gas emissions and to sequester CO2 released from anthropogenic activities. It compares and analyzes, in terms of storage capacity and adsorption selectivity, the innovative technologies that capture CO2. Also described are the key advancements in CO2 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 CO2 adsorption, storage, and separation. Current progress in MOF materials for CO2 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.

Insecticidal potential of zeolite formulations against three stored-grain insects, particle size effect, adherence to kernels and influence on test weight of grains

Laboratory studies were conducted in order to evaluate the insecticidal potential of three commercially available zeolite formulations against adults of Sitophilus oryzae, Tribolium confusum and Oryzaephilus surinamensis in wheat. For each zeolite formulation, three particle size levels were tested, i.e. 0–50, 0–150 and 0–500 μm. Zeolites were applied at three dose rates, 250, 500 and 1000 ppm, and insect mortality was assessed after 2, 7, 14 and 21 d of exposure. After the final mortality count, dead and alive insects were removed and offspring numbers were determined following an additional period of 65 d. In another series of laboratory bioassays, the effect of zeolite application on the test weight of wheat, maize and barley, as well as the adherence of zeolite particles to wheat, maize, barley and rice kernels was also measured. Oryzaephilus surinamensis was the most susceptible species to zeolite application, regardless of the zeolite formulation, dose and particle size level tested, whereas T. confusum was the most tolerant. No significant differences in efficacy were recorded among the three tested zeolite formulations. At the same time, particle size did not affect zeolite efficacy, at least for the particle size levels tested. All zeolites caused a significant reduction on the test weight of the treated grains. Moreover, zeolite particles showed different adherence among wheat, maize, barley and rice kernels. The results of the present study indicate that zeolites can be used with success as grain protectants, but there is a considerable effect on some physical properties of the grains. This information aims to encourage further evaluation of zeolites as grain protectants.

Establishing two-stage interaction between fly ash and NaOH by X-ray and infrared analyses

The interaction of the fly ash and NaOH, in an open reflux hydrothermal system at 100°C, has been explored by several researchers and formation of fly ash zeolites has been confirmed based on the X-ray diffraction analysis of the residues. However, this method does not reveal much about the characteristic transitions (viz. elemental, electro-negativity and cation exchange capacity) of the residues. In this situation, resorting to Fourier transform-infrared radiation (FT-IR) spectroscopy on the residues obtained from two-stage hydrothermal treatment process, described in this manuscript, appears to be a novel idea to establish transitions in chemical bonds (viz., -Si-OH-Al-, OH-Na, OH-Al-), crystallinity and cation exchange capacity of these residues. Based on extensive studies, it has been demonstrated that FT-IR spectroscopy is extremely useful for 1) detection of chemical bonds in the residues, 2) evaluation of zeolites in the residues and 3) also establishing the superiority of the two-stage interaction of the fly ash with NaOH for synthesizing better fly ash zeolites (viz., Na-P1 and Hydroxysodalte) as compared to those obtained from the conventional single-stage treatment of the fly ash.

Evaluation of zeolite A for the sorptive removal of Cs + and Sr 2+ ions from aqueous solutions using batch and fixed bed column operations

Zeolite A was chemically synthesized and evaluated, as inorganic ion exchange material, for the removal of cesium and strontium ions from aqueous solutions in both batch and fixed bed column operations. Batch experiments were carried out as a function of pH, initial ion concentration and temperature. Simple kinetic and thermodynamic models have been applied to the rate and isotherm sorption data and the relevant kinetic and thermodynamic parameters were determined from the graphical presentation of these models. Breakthrough data were determined in a fixed bed column at room temperature (298 K) under the effect of various process parameters like bed depth, flow rate and initial ion concentration. The results showed that the total metal ion uptake and the overall bed capacity decreased with increasing flow rate and increased with increasing initial ion concentrations and bed depth. The dynamics of the ion exchange process was modeled by bed depth service time (BDST) model. The sorption rate constants ( K) were found to increase with increase in flow rate indicating that the overall system kinetics was dominated by external mass transfer in the initial part of the sorption process in the column.

Evaluation of Zeolites in Production of Tetrahydrofuran from 1,4-Butanediol: Performance Tests and Kinetic Investigations

The liquid-phase dehydration of 1,4-butanediol to tetrahydrofuran was investigated over various materials including synthetic zeolites, namely, ZSM-5, Y, Mordenite, Ferrierite, and Beta as well as silica and alumina. The key characters investigated were the Si/Al ratio and cation exchange. The results showed that the ZSM-5 zeolite exchanged with NH4+ exhibited the highest activity in dehydration of 1,4-butanediol. In all tests, nearly 100% selectivity to tetrahydrofuran was observed. After finding the most active catalyst, the kinetics of dehydration of 1,4-butanediol to tetrahydrofuran was studied over this material. The influence of operating parameters such as temperature, pressure, and substrate concentration on reaction was investigated through the Taguchi analysis of experimental data. A strong dependence of reaction rate on temperature was observed. Pressure, however, was found to have a negligible effect on reaction rate. The contribution of external and intraparticle mass transfer limitations on ...

EVALUATION OF FEEDSTOCKS FOR DEVELOPMENT OF HYDROCRACKING CATALYSTS FOR HEAVY OIL

A number of feedstocks namely Arab Light atmospheric residue (ALAR), Arab Heavy atmospheric residue (AHAR), vacuum gas oil (VGO) and hydrotreated vacuum gas oil (HT-VGO), were evaluated for their physical and chemical characteristics. The characterization results of the feedstocks show the complex nature and composition of both residues and gas oils. The distillation results showed that about 50 weight percent of Arab Light crude consists of atmospheric residue. The elemental analysis of the ALAR showed that high amount of carbon, sulfur and nitrogen is present along with heavy metals such as nickel and vanadium. In case of Arab Heavy crude oil, the atmospheric residue is even higher, that is 57 percent and contains higher amount of metals along with more carbon, sulfur and nitrogen contents. The determination of hydrocarbon types by HPLC exhibited that ALAR contains higher amount of saturates compared to AHAR but less amount of aromatics, polars and asphaltenes. ALAR was found to have 55% saturates, 27% aromatics, 12% polars and 6% asphaltenes while AHAR has 30% saturates, 42% aromatics, 18% polars and 10% asphaltenes. Molecular weight determination indicated that the molecular weight of ALAR was determined to be 511 compared to 595 for AHAR. ALAR being lighter, showed 54% distillation at 547°C while AHAR exhibited 45% distillation at 543°C. VGO was found to have 13% saturates, 68% aromatics and 19% polars while HT-VGO had 29% saturates, 63% aromatics and 8% polars. VGO was found to have high IBP and FBP compared to HT-VGO. On the basis of the characterization data, VGO was selected to be use with catalysts containing high pore size supports such as alumina, silica alumina and clay while HT-VGO was selected as feedstock for performance evaluation of zeolite based catalysts. ALAR and AHAR will be utilized in the later stages of the catalysts development work.

Evaluation of Zeolites in the Diet of Broiler Chickens

Two experiments were conducted in which zeolites were added to broiler diets at the 1% level beginning at 21 days of age. In one study, diets with different energy levels were used to determine if an interaction existed between zeolite supplementation and nutrient density. No beneficial effects of zeolite supplementation on body weights were observed in either experiment. There were no statistically significant differences in feed utilization between diets with and without zeolites, and the numerical differences could be accounted for by the addition of 1% inert zeolite.