Synthetic Zeolite Research Articles

Flexible textural design of ZSM-5 zeolite adsorbent from coal fly ash via solvent-free method for toluene elimination

It is feasible and profitable to figure out multidiscipline environmental issues synergistically. Coal fly ash based adsorbent materials are widely used in the emission control of volatile organic compounds. A solvent-free method which was more environmental-friendly for ZSM-5 zeolites synthesis from coal fly ash was proposed to eliminate toluene. The results indicated that ZSM-5 zeolites were successfully synthesized from the precursor gel of coal fly ash with 30–60 wt% moisture contents. The SiO2/Al2O3 mole ratio of gel was up to 99 after the pretreatment of alkali roasting and acid precipitation. During the synthesis process, the appropriate Na2CO3-to-SiO2 ratio was 0.3, and the mesoporous formation would be facilitated along with the moisture content of gel. On the tendency of adsorption testing, the microporous structure was prone to the toluene adsorption, and the desorption was dependent on the mesoporous structure. The maximum adsorption capacity of 75.1 mg·g−1 was observed on S-40 sample, and the minimum desorption activation energy of 39.97 kJ·mol−1 was found on S-60 sample. The humid condition can reduce the toluene adsorption performance, and the maximum adsorption capacity was down to 63.7 mg·g−1. Additionally, the synthetic ZSM-5 zeolites still have some superiority in economics and ecology when compared with commercial zeolites. The novel synthesis method, preparing controllable ZSM-5 zeolites from coal fly ash with the advantages of low cost and environmental friendliness, exhibited the tremendous application potential in environmental field.

Effect of synthetic zeolite on tobermorite synthesis

Chemical anchors are widely used in additional installations of construction irons, repair and reinforcement work. Due to the increasing diversity of materials and the improved awareness of waste products, it has become possible to produce different kinds of concrete, with various properties. In this study, class B420C ribbed bars with 16 mm diameter, were installed in four different concretes by using four different chemical adhesives, and a tensile force was applied. The stiffness, displacement ductility ratio, energy-dissipation capability and tensile force values were determined and the failure modes were interpreted from the load-displacement curves, obtained as a result of the experiments. It was found that the tensile force and energy-dissipation capacity, had increased as a result of installing anchor and applying a tensile force to the concrete, that was obtained by adding admixture materials, to the reference concrete. In the analytical part of the study, the formulation provided in ACI 318 was used, capacity and design strengths were identified, and their safety levels were determined in comparison with the test results.

Effect of Chemical Fertilizer and Tobacco Stalks-derived Biochar on FCV Tobacco Yield, Nutrient Use Efficiency and Carbon Management Index in a Light Textured Alfisol

Aims: To investigate the effect of tobacco stalk biochar (TS Biochar) and synthetic zeolite (SZ) on light textured sandy loam soil in terms of improving the nutrient use efficiency and productivity of FCV tobacco.
 Study Design: Randomized block design (RBD).
 Place and Duration of Study: ICAR-CTRI RS, Jeelugumilli, Andhra Pradesh, India.
 Methodology: Field experiment was conducted with eight treatments and three replications. The treatments included T1: 100 % NPK; T2: 100% NPK + 1 t ha-1 TS Biochar; T3: 100% NPK + 250 kg ha-1 Synthetic Zeolite (SZ) ; T4: 100 % NPK + 1 t ha-1 TS Biochar + 250 kg ha-1SZ; T5: 100% NPK + 0.5 t ha-1 TS Biomass; T6: Adjusted N & K + 1 t ha-1 TS Biochar; T7: 1 t ha-1 TS Biochar + 250 kg ha-1SZ; T8: Control.TS Biochar was characterized for different functional groups using FTIR analysis
 Results: Results revealed that the application of 1 t ha-1 TS Biochar + 100% NPK and 1 t ha-1 TS Biochar +250 kg ha-1 SZ + 100% NPK resulted in a significant increase in tobacco leaf yield compared to the 100% RDF alone . The highest uptake of nitrogen (84.56 kg ha-1) and potassium (122.73 kg ha-1) by tobacco was observed in T2 (100% NPK +1 t ha-1 TS Biochar). Recovery efficiency of N and K applied was greater in tobacco stalk biochar soil amendment with 50.78 and 77.83 per cent as against 100 % NPK alone with 32.83 and 49.64 per cent, respectively. FTIR analysis indicated that TS Biochar is having negative hydroxyl, carbonate and carboxyl functional groups on the surface. Hence, tobacco stalk biochar (TS Biochar) at the rate of 1t ha-1 along with 100% recommended chemical fertilizers can be recommended for the tobacco growing farming community for enhanced yield, nutrient uptake, nutrient use efficiency and soil properties.
 Conclusion: Tobacco stalk biochar (TS Biochar) can serve as soil amendment for enhancing nutrient use efficiency in light textured Alfisols.

OBTAINING NEW MATERIALS BASED ON A COMBINATION OF SYNTHETIC ZEOLITES AND SILVER NANOPARTICLES

Nano silver has long been known as a highly effective disinfectant, capable of limiting the growth and eliminating many types of mold and bacteria. Nano silver can be synthesized by many different methods, depending on the purpose and requirements of use. Nano silver can be dispersed in solution or carried onto carriers for different applications. However, in solution, silver nanoparticles often tend to bind together, reducing antibacterial activity. In order to promote the antibacterial ability of nano silver and be able to recover and reuse many times, as well as to be able to disperse well into different materials, nano silver is often put on the carriers. In this study, nanosilver was synthesized on the surface of a zeolite by simple methods such as chemical reduction with NaBH4, N2H4 or thermal reduction at 350 °C. Ag+ ions are adsorbed onto 4A zeolite by ion exchange mechanism, then reduced by different methods. The materials were morphologically analyzed by XRD, SEM, EDX methods. Results showed that the method of reducing Ag+ to Ag0 on zeolite surface by chemical agent produce more evenly distributed silver nano-sized particles than the thermal reduction method. The silver content on the zeolite surface of the hydrazine reduction method is about 3 times higher than that of the sodium borohydride reduction method. The highest content of silver nanocarrying to zeolite. Zeolite bearing nano silver has the ability to disinfect against E.Coli with a concentration of ≥ 5 mg/ml. The Ag02/Z sample reducing Ag+ to Ag0 by Hydrazin has the best antibacterial ability against E.coli compared with the remaining samples when the diameter of the sterile ring at the concentration of 20 mg/ml is 9 mm. For citation: Xuan Minh Vu, Thi Lan Pham, Thi My Hanh Le, Thi Thu Hoai Pham, Chi Mai Nguyen, Dai Lam Tran Obtaining new materials based on a combination of synthetic zeolites and silver nanoparticles. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2023. V. 66. N 3. P. 59-65. DOI: 10.6060/ivkkt.20236603.6722.

Comparative Analysis of Natural and Synthetic Zeolite Filter Performance in the Purification of Groundwater

Zeolite materials are among the relatively cheap and readily available materials for wastewater treatment. However, the performance of zeolite-based systems can be highly affected by the material properties. In this study, the treatment system based on natural zeolite materials from Chankanai mines in Kazakhstan was compared with a synthetic zeolite treatment system for the purification of groundwater. Water quality indices were also developed from a set of selected water quality parameters to further assess the state of water quality of raw groundwater and the effluents treated with natural and synthetic zeolite. The lowest removal efficiency of natural zeolite (30%) was observed with zinc, while the lowest removal efficiency (36%) of synthetic zeolite was observed with arsenic. With turbidity and beryllium, we observed the maximum removal efficiency (100%) of natural zeolite, whereas with turbidity, we observed the highest removal efficiency (100%) of synthetic zeolite. When the groundwater samples were put through the natural zeolite treatment system, removal efficiency of 50% and above was obtained with 27 (79.4%) out of the 34 water quality parameters examined. On the other hand, when the groundwater samples were put through the synthetic zeolite treatment system, more than 50% removal efficiency was attained with 30 (88.2%) out of the 34 water quality parameters studied. The aggregated water quality index of raw groundwater was 3278.24, falling in the “water unsuitable for drinking” category. The effluent treated with natural zeolite generated 144.82 as a water quality index, falling in the “poor water” quality category. Synthetic zeolite generated 94.79 as a water quality index, falling in the “good water” quality category. Across the board, it was shown that the synthetic zeolite treatment system outperformed the natural zeolite treatment system according to a number of water quality parameters. The findings of this study offer substantial knowledge that can be used to develop more efficient groundwater treatment technologies.

Efficient mercury removal from water by using modified natural zeolites and comparison to commercial adsorbents

The reduction of mercury use in industrial activities and its elimination from waste streams is of great importance to the circular economy approach. In this study a natural zeolite was impregnated with silver to derive Ag+, Ag2O and Ag0 forms. The natural and Ag-zeolites were effectively used for the removal of mercury from Hg(NO3)2 and HgCl2 aqueous solutions. Kinetic experiments, aqueous phase speciation modeling and post-sorption characterizations were used to interpret the sorption behavior of the zeolites. Natural zeolite is effective in removing mercury from Hg(NO3)2 solutions but sorption is negligible from HgCl2 solutions. Silver modification transformed the natural zeolite into an effective nanocomposite sorbent for mercury removal from HgCl2 solutions, the effectiveness being affected by the Ag form. However, Ag modification had no effect on the removal from Hg(NO3)2 solutions. These results demonstrate the strong interplay between ion exchange, surface Ag–Hg reactions and the aqueous phase Hg speciation which was further supported by complementary experiments with iodide under the same conditions. For comparison, Hg removal by commercial adsorbents, namely an activated carbon, a cation exchange resin and synthetic zeolite Y is presented. The results demonstrate that natural zeolite and Ag0 form are effective adsorbents performing better than commercial ion exchangers and are comparable to activated carbon. The use of abundant, cheap, environmental-friendly and easy to modify natural zeolite is an attractive alternative to commercial and other unsustainable and difficult to synthesize adsorbent materials.

Erythromycin Scavenging from Aqueous Solutions by Zeolitic Materials Derived from Fly Ash.

Erythromycin (EA) is an antibiotic whose concentration in water and wastewater has been reported to be above the standard levels. Since the methods used so far to remove EA from aquatic environments have not been effective, the development of effective methods for EA removal is necessary. In the present study, fly ash (FA)-based zeolite materials, which have not been investigated as EA sorbents before, were used. The possibilities of managing waste FA and using its transformation products for EA sorption were presented. The efficiency of EA removal from experimental solutions and real wastewater was evaluated. In addition, the sorbents' mineral composition, chemical composition, and physicochemical properties and the effects of adsorbent mass, contact time, initial EA concentration, and pH on EA removal were analyzed. The EA was removed within the first 2 min of the reaction with an efficiency of 99% from experimental solutions and 94% from real wastewater. The maximum adsorption capacities were 314.7 mg g-1 for the fly ash-based synthetic zeolite (NaP1_FA) and 363.0 mg g-1 for the carbon-zeolite composite (NaP1_C). A fivefold regeneration of the NaP1_FA and NaP1_C showed no significant loss of adsorption efficiency. These findings indicate that zeolitic materials effectively remove EA and can be further investigated for removing other pharmaceuticals from water and wastewater.

Study on electrical double layer nanostructure on zeolitic materials’ surface in the presence of impurities of different nature

The aim of the research was to compare the adsorption mechanisms of heavy metal ions (Pb(II) and Zn(II)), as well as organic substances [diclofenac molecules and pol(acrylic acid) macromolecules on the surfaces of Na-X and Na-P1 synthetic zeolites as well their Na-X© and Na-P1© carbon composites]. The single and mixed adsorbate systems were considered. The more probable structures of the formed adsorption layers were proposed based on the results of the solid surface charge density and zeta potential experiments. The great applicability of the analysis of the parameters characterizing the electrical double layer in determination of the binding mechanism of simple inorganic ions and more complex organic molecules on the surface of the examined solids from the one- and two-component solutions was proved. Moreover, the changes of the surface and electrokinetic factors after the addition of the organic molecules enable specification of drug molecule orientation as well as the polymeric chain conformation at the solid/liquid interface.

Green activating silica-alumina insoluble phase of fly ash to synthesize zeolite P with high adsorption capacity for Pb(II) in solution

Using fly ash as a raw material to synthesize zeolite is an effective way to obtain cheap adsorbent. However, the high energy consumption of activating the insoluble silica-alumina phase of fly ash limits its practical application. In this study, a low-energy, wet-grinding hydrothermal method was used to activate the insoluble phase of fly ash to synthesize zeolite P, and the adsorption capacity of zeolite for lead ion in solution was studied. Wet-grinding can reduce fly ash particle size to nanometer scale and break long-chain Q4(Al) into short-chain low-polymer. Without aging, the activated material could directly synthesize zeolite P with a relative crystallinity of 89.37 %. Compared with the common alkali-fusion method, the wet-grinding method reduced energy consumption by 45.93 % and increased synthetic zeolite relative crystallinity by 7.51 %. The synthesized zeolite P could effectively remove Pb2+ ions from solution through ion exchange and hydroxyl reaction, and the adsorption capacity reached 497.01 mg/g.

Mechanical Properties Enhancement of the Cement Mortar by Synthetic Zeolite Polymer Composites

The performance of cement mortar can be improved with additives based on waste by-products. Synthetic zeolite polymer composites (referred as SZPC) produced from the combination of solid waste ashes with a selective acrylic compound was used as a cement mortar additive. The effect of SZPC as an additive on hydration reaction of ordinary Portland cement (referred as OPC) at different amounts of SZPC, from 1-4% of OPC weight, as well as microstructure and mechanical behavior of the cement mortar are determined. The results from the hydration reaction rate test showed that the optimum amount of SZPC as the additive was 2% of OPC weight. Compressive strength and flexural strength of the cement mortar after 1, 7, 14 and 28 days of curing increased, with the largestincreases at the early stage. Additions of SZPC, synthesized by a waste by-product, improved mechanical behavior of cement mortars supporting sustainable development and the circular economy.

Thermodynamics of hydrogen sulfide adsorption in NaX zeolite

Sulfur-containing organic and inorganic compounds are the main harmful component of natural gas and oil, as well as products of their processing. Since sulfur compounds have acidic properties, their content leads to corrosion of technological parts in production processes. The content of hydrogen sulfide in the transported gas should not exceed 20 mg/m3. In Uzbekistan, motor vehicles run mainly on liquefied natural gas. Sulfur compounds in natural gas corrode gas cylinders, resulting in an explosion. If synthetic zeolites are used in manufacturing processes, as well as in small gas production, process degradation will be prevented. Synthetic zeolites are widely used in various industrial production processes due to their high sorption properties. This study makes it possible to study the localization and sorption structure of sulfur compounds in supercavities of zeolites of the faujasite type. The adsorption of hydrogen sulfide on NaX zeolite was carried out in a high vacuum adsorption unit. Based on the results obtained, the differential heat of adsorption, isotherm, entropy, and thermal equilibrium time (thermokinetics) were calculated.

Self-supported MOF/cellulose-nanocrystals materials designed from ultrafiltration.

Metal-organic-frameworks (MOFs) are promising materials for addressing critical issues such as petrochemical separation, water purification, energy storage and drug delivery. Their large-scale deployment, however, is hampered by a limited processability due to their powdery nature. Recently, the hybridization of MOFs with biopolymers has emerged as a greener, biocompatible strategy to shape MOFs composites into more processable membranes, films, and porous materials. In this work, cellulose nanocrystals (CNCs) were used in combination with ZIF-8 (a widely used synthetic zeolite) to produce hybrid composites through ultrafiltration. Results showed that small quantities of CNCs (1 to 20 CNC:ZIF-8 volume ratio) were sufficient to form a self-supported, dense deposit with high ZIF-8 loadings. Compared to classical MOF in situ growth strategies, this approach allowed the tuning of the composition of the final nanocomposite by controlling the nature and quantities of particles in the suspension. The fabrication of the deposit was strongly dependent on the physiochemical properties of the suspension, which were fully characterized with a set of complementary techniques, including in situ SAXS. This technique was employed to investigate the filtration process, which exhibited a homogeneous deposition of ZIF-8 particles mediated by CNC self-assembly. Finally, the available pore volume and integrity of the internal porosity of ZIF-8 were characterized by water porosimetry, demonstrating that the presence of CNCs did not alter the properties of the supported ZIF-8.

Simultaneous removal of nitrogen and phosphorus from urban sewage by synthetic zeolites adsorption: performance, characterization, and mechanism

Simultaneous removal of nitrogen and phosphorus from urban sewage by synthetic zeolites adsorption: performance, characterization, and mechanism

Comparative study on the performance of two synthetic zeolite 4A on the removal of heavy metals from aqueous solution—effect of coal fly ash as Al and Si source

Comparative study on the performance of two synthetic zeolite 4A on the removal of heavy metals from aqueous solution—effect of coal fly ash as Al and Si source

Synthetic zeolite derived from coal fly ash decorated with magnetic alginate bead: Application to detoxification of arsenic and vanadium

Abstract Heavy metal toxicity is highly demanding and challenging to clean up the pollutants. To recover the issues mentioned above, we propose a hydrothermal synthesis of zeolite (NaX-UP). Further surface modification by poly-ethylenimine (PEI) could turn to be amine-modified zeolite nanosheets (zeolite NSs) possessed plenty of hydroxyl and amino groups (Al-O, Si-O-Si, Si-OH and NH2) on their surface, decorated with magnetic nanoparticles (Fe3O4 NPs), that are enabled to bridge with inter and intramolecular hydrogen bonding an additionally electrostatic interaction might be a significant role. Further, this can be converted into magnetic bead crosslinking with sodium alginate immersed in an excess calcium chloride solution. The-as formed Fe3O4 NPs decorated amine modified zeolite alginate bead denoted to be (Fe3O4 NPs decorated @PEI-zeolite NSs alginate bead) upholding a significant advantage would aim to clean up the anionic pollutants are [As(V) & V(V)] from an aqueous solution.

Comparison of the Sorption Capacities of Synthetic Zeolite and Divalent Metal Phosphates

Comparison of the Sorption Capacities of Synthetic Zeolite and Divalent Metal Phosphates

Differential heats, isotherm and entropies of n-pentane adsorption on LiZSM-5 and CsZSM-5 zeolites

Artificially synthesised zeolites are widely used in water purification devices as adsorbents, ion exchangers, molecular sieves; they are used as electron donors and acceptors. Also, zeolites are currently the most important catalysts for the processing of various hydrocarbon raw materials. Synthetic zeolites ZSM-5 are highly efficient catalysts of these processes. For o characterisation of zeolite channels and estimation of sorption volume npentane are the most suitable. n-Pentane fills all sorption space and adsorbed with higher energy. This paper presents the results of the basic thermodynamic characteristics and isotherms of n-pentane adsorption in Cs3,17ZSM- 5 and Li3,37ZSM-5 zeolites at 303 K. A system consisting of a universal high-vacuum adsorption unit and a Tian-Calvet type differential modified microcalorimeter, DAC-1-1A, coupled to it was used to measure isotherms and differential heats of adsorption. The correlation between adsorption-energy characteristics was found and the molecular mechanism of n-pentane adsorption in CsZSM-5 and LiZSM-5 zeolites in the whole filling region was revealed.

INFLUENCE OF THE NATURE OF THE ALUMINUM SOURCE ON THE PHYSICO-CHEMICAL CHARACTERISTICS OF THE CARRIER OF CATALYTIC SYSTEMS FOR THE PETROCHEMICAL INDUSTRY

In the oil refining industry of the Republic of Kazakhstan, catalysts based on synthetic zeolites are mainly used. However, it was found that catalysts of this type have a number of disadvantages. For example, most of them have pore sizes in the micropore range, which is the reason for diffusion limitations. The solution to this problem can be found by creating catalysts based on mesoporous aluminosilicate. Mesostructured aluminosilicates are widely used as catalysts for petrochemical processes due to their high specific surface area, highly ordered pore structure and narrow pore size distribution and the possibility of regulating the size of their pores during synthesis. Mesoporous aluminosilicates are widely used as catalysts for petrochemical processes due to their high specific surface area, highly ordered pore structure and narrow pore size distribution and the possibility of regulating the size of their pores during synthesis. The article presents the synthesis of mesoporous aluminosilicates by copolycondensation of tetraethylortosilicate with various sources of aluminum: secondary aluminum butoxide (MAS-1) and aluminum triisopropoxide (MAS-2). The presence of a mesoporous and ordered structure in the synthesized aluminosilicates was confirmed by the data of low-temperature nitrogen adsorption/ desorption, X-ray diffraction and FT-IR. Acidic data were investigated by the method of infrared spectroscopy of the Fourier transform with diffuse reflection (DRIFT). It is shown that the nature of the aluminum source affects both the specific surface area and porosity, and the acidic characteristics of the synthesized mesoporous aluminosilicates.

Evaluation of high‐performance adsorbents for separation of CO2 from industrial effluent gases

AbstractThe aim of this work is the investigation of several CO2 adsorbents such as three synthetic zeolites (4A, 5A, and 13X), a natural zeolite (clinoptilolite), an activated carbon (AC), and a metal organic framework (MOF‐MIL‐53) for the postcombustion CO2 capture via temperature‐pressure swing adsorption. The adsorbents were evaluated in terms of the CO2 adsorption capacity and performance during successive adsorption–desorption cycles at different conditions (1–6 bar and 120–180°C) using different mixtures of gases simulating a combustion process stream (N2/CO2/O2/CO). The 13X zeolite showed excellent adsorption capacity of 4.3 mmolCO2/g zeolite and very stable performance during successive cycles. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd.

Preparation of chabazite based Fenton-like heterogeneous catalyst and its organic micropollutant removal performance

Natural chabazite (CHA) is used for the first time as a heterogeneous catalyst in Fenton-like oxidation. Pretreatment techniques (NH4+-exchange, steam treatment, and Fe-exchange) were applied to natural CHA to improve the available micropore and mesopore volume as well as to increase Fe-content. CHA samples were characterized by XRD, N2 adsorption, UV–Vis, SEM-EDX, ICP-OES, and MAS NMR to study the improvement after each pretreatment. Steam treatment at 675 °C and 20 kPa improved the mesopore volume of CHA, which enabled Fe3+ concentration to increase from 0.24 to 0.60 mmol Fe3+ g CHA−1 following the Fe-exchange. The Fe-exchanged CHA (Fe-CHA) was then tested for malathion oxidation. The effect of H2O2 and catalyst doses and pH on the degradation of malathion was investigated. Fenton-like oxidation was realized at a higher and wider pH range (pH 3–7) when compared to classical Fenton. A malathion removal between 20 and 81% was achieved depending on the initial malathion concentration (250–750 μg L−1), Fenton Reagents (H2O2 and Fe-CHA) concentrations (75–300 mg L−1 and 250–750 mg L−1, respectively) and pH (3–7). The metabolites of malathion were identified as malaoxon, desmethyl malaoxon and diethyl malate. A possible oxidation pathway was proposed, where desmethyl malaoxon and diethyl malate were identified as the secondary oxidation products. Moreover, the performance of Fe-CHA was compared with commercially available synthetic zeolites of Fe-Ultra-stable Y and Fe-ZSM-5. Fe-CHA is found to be comparably effective as these synthetic zeolites, as well as providing substantially smaller sludge production when compared to classical Fenton.