Synthetic Zeolite Research Articles

MECHANICAL PROPERTIES AND MICROSTRUCTURE OF CONCRETE INCORPORATING SYNTHETIC ZEOLITE

The effect of natural and synthetic zeolite on the microstructure of cement matrix and mechanical properties of concretes was studied in the article. Results show that the addition of these pozzolanic materials results in the increase both compressive and flexural strength after 28 days of hardening. The concrete incorporating 10 mass.% of synthetic zeolite Na-P1 characterizes the highest compressive and flexural strength that reaches 53.5 and 7.8 MPa and exceeds the strength of reference concrete by 18 and 24%, respectively. This increase is the result of the improvement of the concrete on the microstructural level due to the formation of the additional amount of fibre-like crystals of hydrosilicates in the non-clinker part of the cement matrix providing its self-reinforcement.

Optimization of process parameters of catalytic pyrolysis using natural zeolite and synthetic zeolites on yield of plastic oil through response surface methodology

Optimization of process parameters of catalytic pyrolysis using natural zeolite and synthetic zeolites on yield of plastic oil through response surface methodology

RESEARCH OF THE EFFICIENCY OF ORGANIC MATTER REMOVALFROM WATER USING SYNTHETIC ZEOLITE

The paper investigated the effectiveness of using synthetic zeolite as an adsorbent for the removal of organic matter from water. Characterization of zeolite was performed using advanced testing methods: XRD, FTIR, BET and SEM/EDS. Raw water was analyzed for physicochemical characteristics before treatment (turbidity, color, pH,conductivity, content of organic matter, ammonia, nitrate and nitrite nitrogen, iron, manganese and chloride) and after treatment with an adsorbent (content of organic matter). Research on the efficiency of adsorption was carried out under the conditions of water temperature 25°C, individual doses of zeolite of 1, 2 and 4 g/L, mixing 200 rpm and adsorption time 60 minutes. The obtained results showed that by applying synthetic zeolite in a dose of 1 g/L, it is possible to achieve the removal of organic matter of 71.2%, while increasement of that dose up to four times has an insignificant effect on the adsorption efficiency. KEYWORDS:synthetic zeolite; organic matter removal

Study on rutting performance of synthetic zeolite based warm mix asphalt using railway carriage workshop incineration ash as filler

Study on rutting performance of synthetic zeolite based warm mix asphalt using railway carriage workshop incineration ash as filler

Fragrance Carrier Based on Zeolite-A Modified Bentonite as a Controlled Release System in Air Freshener Applications

The quality of air fresheners with low cost production can be improved by using a carrier matrix such as synthetic zeolite to increase the long-lasting properties of fragrance product by encapsulation technique. The zeolite A is considerdas a safe core fragrance carrier matrix to be able to release volatile fragrance from their pores when exposed to atmospheric humidity at room temperature. Zeolite A was synthesized from natural kaolin and was formed into tube pellets with bentonite (20 wt.%) as binder to produce zeolite A-bentonite (ZAB) cylindrical pellets composite and used as a fragrance carrier matrix with a rose essential oil (Rose damascena Mill.) as parfume model. The fresh bentonite can also adsorb the rose essential oil with adsorption capacity of 1.745 g/g bentonite (74.5%). Effects of chemical activation on zeolite-A using acid (HCl) of 0.1 M and base (NaOH) of 0.1 M were studied. The ZAB tube pelletes were found to have high adsorption efficiencies of rose essential oil. ZAB4 has the highest efficiency and was used for regeneration test studies that was carried out over 10 cycles using HCl and NaOH, where the adsorption efficiency was 94.5 and 75.4%, respectively. The activated ZAB4 composite using HCl has a long life time until more than 5 weeks and more than 10 regeneration cycles. This fragrance carrier matrix based on ZAB has significant potential for extended carrier fragrance system.

The effect of natural and synthetic zeolites on polysaccharidase activity in the rumen of Jersey heifers

The effect of natural and synthetic zeolites on polysaccharidase activity in the rumen of Jersey heifers

Loading Self-Assembly Siliceous Zeolites for Affordable Next-Generation Wearable Artificial Kidney Technology.

The global demand for dialysis among patients with end-stage kidney disease has surpassed the capacity of public healthcare, a trend that has intensified. While wearable artificial kidney (WAK) technology is seen as a crucial solution to address this demand, there is an urgent need for both efficient and renewable toxin-adsorbent materials to overcome the long-standing technological challenges in terms of cost, device size, and sustainability. In this study, we employed screening experiments for adsorbent materials, multimodal characterization, and Monte Carlo adsorption simulations to identify a synthetic self-assembly silicalite-1 zeolite that exhibits highly ordered crystal arrays along the [010] face (b-axis) direction, demonstrating exceptional adsorption capabilities for small molecular toxins such as creatinine and urea associated with uremia. Moreover, this metal-free, cost-effective, easily synthesized, and highly efficient toxin adsorbent could be regenerated through calcination without compromising the performance. The simulated toxin adsorption experiments and comprehensive biocompatibility verification position it as an auxiliary adsorbent to reduce dialysate dosages in WAK devices as well as a potential adsorbent for small-molecule toxins in dialysis. This work is poised to propel the development of next-generation WAK devices by providing siliceous adsorbent solutions for small-molecule toxins.

Evaluation of multifunctional marine coatings enriched with organometallic biocides supported on ZSM-5 zeolite for biofouling prevention

There is significant concern regarding the biocides commonly used in commercial antifouling protection systems because of their high concentrations in coastal areas and the potential harm they can cause to marine organisms. Thus, much research has been dedicated to replacing these biocides with environment-friendly alternatives. Particularly, the use of natural products that inhibit the settlement of fouling organisms is the key to antifouling coating technology. The purpose of this study was to develop antifouling paints by using eco-friendly compounds and implement a multifunctional coating factor. Natural-origin biocidal agents, such as capsaicin, and a copper-ion release system supported on synthetic zeolite ZSM-5 were used. The formulations resulted in viscosities and particle sizes similar to those of commercial antifouling paints. The capsaicin coatings exhibited less fracture damage and more resistance to deformation in the flexibility and cupping tests. In the adhesion tests, all formulations exceeded 3 MPa, thereby enhancing the adhesion values of conventional antifouling agents. However, the capsaicin coatings exhibited less abrasion resistance than those containing zeolite. Corrosion resistance tests using electrochemical impedance spectroscopy indicated good anti-corrosive properties, particularly in the coatings with 8 % and 10 % copper. All formulations proved to be bactericidal within 6 h, and some completely eliminated the cell density by 3 h, highlighting the effectiveness of the biocide against the marine strain Pseudoalteromonas sp. UCO92.

Enhanced pozzolanic reactivity in hydrogen-form zeolites as supplementary cementitious materials

Pozzolans rich in silica and alumina react with lime to form cementing compounds and are incorporated into portland cement as supplementary cementitious materials (SCMs). However, pozzolanic reactions progress slower than portland cement hydration, limiting their use in modern construction due to insufficient early-age strength. Hence, alternative SCMs that enable faster pozzolanic reactions are necessary including synthetic zeolites, which have high surface areas and compositional purity that indicate the possibility of rapid pozzolanic reactivity. Synthetic zeolites with varying cation composition (Na-zeolite, H-zeolite), SiO2/Al2O3 ratio, and framework type were evaluated for pozzolanic reactivity via Ca(OH)2 consumption using ion exchange and in-situ X-ray diffraction experiments. Na-zeolites exhibited limited exchange reactions with KOH and Ca(OH)2 due to the occupancy of acid sites by Na+ and hydroxyl groups. Meanwhile, H-zeolites readily adsorbed K+ and Ca2+ from a hydroxide solution by exchanging cations with H+ at Brønsted acid sites or cation adsorption at vacant acid sites. By adsorbing cations, the H-zeolite reduced the pH and increased Ca2+ solubility to promote pozzolanic reactions in a system where Ca(OH)2 dissolution/diffusion was a rate limiting factor. High H-zeolite reactivity resulted in 0.8 g of Ca(OH)2 consumed per 1 g of zeolites after 16 h of reaction versus 0.4 g of Ca(OH)2 consumed per 1 g of Na-zeolite. The H-zeolite modulated the pore fluid alkalinity and created a low-density amorphous silicate phase via mechanisms analogous to two-step C-S-H nucleation experiments. Controlling these reaction mechanisms is key to developing next generation pozzolanic cementitious systems with comparable hydration rates to portland cement.

Modification of the polymeric admixture based on polycarboxylate ether using silica-derived secondary materials obtained from fly ash and the efficiency of its application in concrete

The rising energy prices and the costs of CO2 emissions into the atmosphere are forcing the construction industry to search for ways to reduce cement consumption in concrete technology by optimizing concrete mixtures and making greater use of chemical admixtures. The scientific problem lies in understanding how polymers modified with silica-derived secondary materials, such as those obtained from fly ash (e.g., synthetic zeolites, mesoporous silica), interact with the concrete matrix and influence their durability and strength. The present study investigated the effect of a polymeric admixture based on polycarboxylic ether (PCE) modified with silica-derived secondary materials obtained from fly ash (synthetic zeolites, mesoporous silica) on the physical and mechanical properties of concrete. The study considered the effect of the modified polymer admixture dosed in 3 different amounts (0.4%, 0.8% and 1.2%) by weight of cement on the fresh properties of the concrete mixture, i.e. consistency and air content. The research scope also included determining the physico-mechanical properties of the concretes and investigating the effect of the modified admixture on the frost durability of the cement composite. In order to study the modification of the concrete microstructure, XRD phase analysis and air pore structure analysis by MIP were carried out. The study showed an increase in compressive strength after 28 days of curing in concretes containing the modified polymer of about 8-12% compared to the reference concrete. In addition, it was observed that strength increased with increasing admixture dosage. The resulting pore structure, contributed to improving the frost resistance of the concretes by reducing compressive strength loss from about 14% in reference concretes to about 2-9% in concretes with the modified polymer after 150 cycles of alternating freeze-thaw. At the same time, it was observed that the use of the modified polymer resulted in an increase in weight absorption from 2% do 4.5%, a more than twofold increase in depth of penetration of water under pressure and a more than 70% increased total porosity. In conclusion, the polymer-modified MCM-41 can positively affect the mechanical and durability properties of concrete, but it causes a change in the pore structure, which could have a negative effect on water absorption and total porosity.

Synthesis of iron-loaded MFI-type (Fe/ZSM-5) zeolite using Philippine natural zeolites (PNZ) for potential adsorption and catalytic applications

Abstract Philippine natural zeolites (PNZ) are locally abundant aluminosilicates used in different applications such as filtration and purification. However, the presence of impurities limits their usability. Structure modification of PNZ into a new framework was conducted in the study to address this issue. This study used PNZ as a precursor in the sustainable synthesis of iron-loaded MFI-type (Fe/ZSM-5) zeolite, a synthetic zeolite extensively studied for its excellent catalytic activity and high adsorption capacity. PNZ was depolymerized into active silica and alumina, then recrystallized via hydrothermal synthesis. Ammonium iron citrate (AIC) and TPAOH were used as the iron source and structure-directing agent, respectively. The disappearance and appearance of FTIR peaks in the depolymerized PNZ spectra deduced the successful destruction of the initial zeolite framework of the PNZ. The synthesized material was characterized using FTIR, XRD, SEM-EDS, TGA, and BET analyses. FTIR showed the crystallinity peak of MFI-type zeolite, while XRD confirmed its successful synthesis. SEM images show hierarchical aggregated particles suggesting the presence of intercrystalline and intracrystalline mesopores. The BET surface area of the synthesized zeolite increased by 168% compared to the raw PNZ, and TGA results show its high thermal stability. EDS analysis confirmed the presence of iron in the sample.

Sintesis Zeolit dari Abu Sekam Padi (OryzaSativa L.) Serta Uji Efektifitasnya Sebagai Material Antiseptik

Rice husks are obtained from 20% rice milling and have a silica content of 94-99% of ashed rice husks. Zeolite is a silica-based material and is known as an aluminosilicate compound, because it is formed from two main components, namely tetrahedral AlO4- and SiO4¬-. Synthetic zeolite is obtained by reacting Sodium Silicate (A) with Sodium Aluminate (B) which is then aged at 100oC for 24 hours to produce white synthetic Zeolite powder. Zeolite synthesis will be made with three variations of mixture ratios, namely 30A:70B, 50A:50B, 70A:30B and the characteristics of each will be evaluated. To test the success of this synthetic zeolite as an antiseptic material, its ability to reduce the infectious value of Bacteriuria and Candiduria will be tested, which will be represented by Escherecia coli and Candida albicans. The results obtained from the three variations of synthetic zeolite that were made had the same characteristics and had a ratio of less than two or type A. Synthetic zeolite made at a dose of 600 mg had the ability to act as an antiseptic material against Escherichia coli 104 by reducing the number of colonies to 72-79 %, as well as Candida albicans 103 was able to reduce the number of C. albicans colonies by 74-80%, this value is lower than Attapulgite 600mg in reducing the same number of colonies, namely 90% for bacteriuria and 94.90% for candiduria. To equalize its capabilities with Attapulgite 600 mg, the dosage of the synthetic zeolite obtained in the research was increased to 700 mg

Waste Symbiosis through the Synthesis of Highly Crystalline LTA and SOD Zeolites.

In recent years, the demand for natural and synthetic zeolites has surged due to their distinctive properties and myriad industrial applications. This research aims to synthesise crystalline zeolites by co-recycling two industrial wastes: salt slag (SS) and rice husk ash (RHA). Salt slag, a problematic by-product of secondary aluminium smelting, is classified as hazardous waste due to its reactive and leachable nature, though it is rich in aluminium. Conversely, RHA, an abundant and cost-effective by-product of the agro-food sector, boasts a high silicon content. These wastes were utilised as aluminium and silicon sources for synthesising various zeolites. This study examined the effects of temperature, ageing time, and sodium concentration on the formation of different zeolite phases and their crystallinity. Results indicated that increased Na+ concentration favoured sodalite (SOD) zeolite formation, whereas Linde type-A (LTA) zeolite formation was promoted at higher temperatures and extended ageing times. The formation range of the different zeolites was defined and supported by crystallographic, microstructural, and morphological analyses. Additionally, the thermal behaviour of the zeolites was investigated. This work underscores the potential to transform industrial waste, including hazardous materials like salt slag, into sustainable, high-value materials, fostering efficient waste co-recycling and promoting clean, sustainable industrial production through cross-sectoral industrial symbiosis.

Investigation of alite hydration in the presence of low- and high-silica zeolites

Synthetic zeolites that are obtained from the hydrothermal reaction of NaOH with fly ash have a well-defined pore structure and pozzolanic properties. This work examines the effect of the low-silica (Na-A) and high-silica (ZSM-5) zeolite structure on the kinetics of alite hydration and mineralogical characteristics of the reaction products. The addition of the Na-A and ZSM-5 zeolites reduced the rate of heat release during the hydration reaction, which is typical for commonly used pozzolanic additives. The ZSM-5 zeolite had a much higher Si/Al ratio relative to the Na-A zeolite, which translated into a higher pozzolanic activity and resulted in greater stability of the hydration reaction kinetics. The addition of zeolites caused the heat of hydration to decrease compared to the reference pastes (the alite reference paste—206 J/g): Na-A 15%—148.9 J/g; ZSM-5 15%—149.9 J/g. The concentration of calcium ions in the alite solution and the content of active silica were identified as the most important parameters affecting the kinetic, morphological, and structural characteristics of the C–S–H phase. The addition of zeolites increased the amount of C–S–H gel phases formed. At the same time, the proportion of portlandite in the hydration products of the alite–zeolite systems decreased. Pozzolans reduced the ratio of CaO/SiO2 in the C–S–H phase, which for pastes with the addition of the Na-A ranged from 1.61 to 1.37, and for the ZSM-5 from 1.91 to 0.47. This ratio decreased with the dosage and the age of alite paste. In summary, this research has shown that synthetic zeolites are a viable pozzolanic additives.

Using Zeolite Materials to Remove Pharmaceuticals from Water.

Pharmaceutical drugs, including antibiotics and hormonal agents, pose a significant threat to environmental and public health due to their persistent presence in aquatic environments. Colistin (KOL), fluoxetine (FLUO), amoxicillin (AMO), and 17-alpha-ethinylestradiol (EST) are pharmaceuticals (PhCs) that frequently exceed regulatory limits in water and wastewater. Current removal methods are mainly ineffective, necessitating the development of more efficient techniques. This study investigates the use of synthetic zeolite (NaP1_FA) and zeolite-carbon composites (NaP1_C), both derived from fly ash (FA), for the removal of KOL, FLUO, AMO, and EST from aquatic environments. Batch adsorption experiments assessed the effects of contact time, adsorbent dosage, initial concentration, and pH on the removal efficiency of the pharmaceuticals. The results demonstrated that NaP1_FA and NaP1_C exhibited high removal efficiencies for all tested pharmaceuticals, achieving over 90% removal within 2 min of contact time. The Behnajady-Modirshahla-Ghanbary (BMG) kinetic model best described the adsorption processes. The most effective sorption was observed with a sorbent dose of 1-2 g L-1. Regarding removal efficiency, the substances ranked in this order: EST was the highest, followed by AMO, KOL, and FLUO. Sorption efficiency was influenced by the initial pH of the solutions, with optimal performance observed at pH 2-2.5 for KOL and FLUO. The zeolite-carbon composite NaP1_C, due to its hydrophobic nature, showed superior sorption efficiency for hydrophobic pharmaceuticals like FLUO and EST. The spectral analysis reveals that the primary mechanism for immobilizing the tested PhCs on zeolite sorbents is mainly due to physical sorption. This study underscores the potential of utilizing inexpensive, fly ash-derived zeolites and zeolite-carbon composites to remove pharmaceuticals from water effectively. These findings contribute to developing advanced materials for decentralized wastewater treatment systems, directly addressing pollution sources in various facilities.

Synthetic Zeolite from Blast Furnace Slag (BFS) as an effective sorbent for simultaneous removal of Cadmium and Copper ions

The main challenge for remediation of metals contaminated water is the application of a proper, effective, low-cost material for decontamination of hazardous metal. In this study, low-cost zeolite derived from blast furnace slag (Z-BFS) by a facile hydrothermal method was investigated for adsorption of copper (Cu2+) and cadmium (Cd2+) ions from aqueous solutions. Furthermore, the characteristics of the prepared Z-BFS were evaluated via different techniques (FT-IR, XRF, XRD, SEM and EDX). The results showed the complete removal of Cd2+ and Cu2+ ions. Notably, the maximum adsorption capacity of metals had the trend Cu2+ (103 mg/g) > Cd2+ (80 mg/g) within 20 min at pH 5.5 and 2 g Z-BFS/l. The experimental data fit well with the pseudo-second order kinetic model elucidating that chemisorption is the rate determining step. The isotherms of adsorption were satisfactorily described by the Langmuir isotherm model indicating the monolayer adsorption process. The thermodynamic study demonstrated that adsorption process is endothermic. The obtained results from this study show that Z-BFS proves to be a proper candidate adsorbent for the removal of Cd2+ and Cu2+ ions from contaminated water.

Investigation of hydrogen uptake capacity for FAU, MOR, MTW, MWW

In this study, the hydrogen storage properties of various synthetic zeolites, including Zeolite Y (FAU), Mordenite (MOR), ZSM-12 (MTW), and MCM-22 (MWW) are determined at 77 K and atmospheric pressure. The structures of the zeolites are characterized by XRD, ICP-OES, FE-SEM, TGA and N2 adsorption-desorption isotherms. The results show that H-MCM-22 zeolite has the highest hydrogen storage capacity at 1.0 bar with 1.19 wt%, followed by H-MOR zeolite with 1.05 wt%, H–Y zeolite with 0.75 wt% and H-ZSM-12 zeolite with 0.60 wt%. The hydrogen adsorption data on FAU, MOR, MTW, and MWW at 77 K obey the Sips isotherm model. The experimental data show that the ultra-micropore volume of the zeolite is effective in hydrogen adsorption at low-pressure ranges. In addition, increasing the aluminum content of the zeolite increases the hydrogen adsorption capacity of the zeolite at atmospheric pressure. Therefore, zeolites with channel sizes close to the kinetic diameter of a hydrogen molecule, large cage volumes, and high aluminum content are potential candidates for energy storage applications.

Fixed-bed adsorption of methylene blue using granular NaX zeolite/attapulgite composite: efficiency, mechanism and reusability of saturated G-NaX/A

A novel granular NaX zeolite/attapulgite (G-NaX/A) composite was developed to address the challenges of high pressure drop in fixed beds with powder synthetic zeolite and low adsorption capacity of natural zeolite. The synthesized G-NaX/A retains the micropores of NaX and the mesoporous of attapulgite. The BET specific surface area reached 481.17 m2/g, and the total pore volume was 0.3549 cm3/g. The G-NaX/A maximum methylene blue (MB) adsorption capacity was 1.56 times that of commercial granular activated carbon (7.41 mg/g). The breakthrough time and adsorption capacity improved with lower influent flow rate and MB concentration and higher pH. Under optimal conditions (flow rate: 150 mL/min, MB concentration: 25 mg/L, pH = 8), it achieved a maximum adsorption capacity of 11.51 mg/g and a breakthrough time of 2.54 h. The adsorption behavior of G-NaX/A was well-fitted by the Yoon–Nelson and Thomas models at different operating conditions. The mechanism studies revealed that MB (cation: C16H18SN3+) removal by G-NaX/A occurred through electrostatic attraction, ion exchange with Na+/Mg2+, surface coordination with ≡Al/SiOH, and surface physical adsorption. The regeneration studies confirmed the reusability potential of G-NaX/A by calcining at 500 °C for 2 h, and significantly improved adsorption capacity reaching about 14.39 mg/g, 16.31 mg/g and 14.07 mg/g across the three adsorption-regeneration cycles respectively. The findings support G-NaX/A technical feasibility, high adsorption capacity and potential for further scaling in fixed bed adsorption studies.

Analysis of nitrogen adsorption capability at various activation temperatures of Klaten natural zeolite

The Pressure Swing Adsorption (PSA) method operates by passing air through an adsorbent to produce concentrated oxygen gas. Zeolites are commonly utilized as adsorbents due to their ability to adsorb nitrogen from the surrounding air. Two types of zeolites commonly employed are natural and synthetic zeolites. While the utilization of natural zeolites as adsorbents in oxygen purification remains limited, their potential as an alternative adsorbent is worth exploring in this field. This study focused on developing physically activated Klaten natural zeolite as an adsorbent to enhance oxygen purity. Physical activation involved heating for 1.5 hours using an electric oven at four temperature variations (250ºC, 300ºC, 350ºC, and 400ºC). Additionally, four distinct flow rates were tested: 0.1; 0.5; 1.0; and 1.5 lpm. Oxygen purification testing revealed that higher activation temperatures led to greater increases in oxygen concentration. The highest increase of 2.45% was achieved at an activation temperature of 400ºC, while the lowest increase of 1.75% was observed at 250ºC with a flow rate of 0.1 lpm. With a 10-minute holding period, oxygen content during the adsorption process ranged from 1.35% to 2.45%, compared to 0.60%-0.75% without holding. Physical activation of zeolite from Klaten enhanced its nitrogen absorption capacity, indicating the potential of natural zeolite from Klaten for oxygen purification through optimized activation processes, possibly via chemical activation

In situ epoxidation of oleic acid with applied natural zeolite as a catalyst

AbstractIn recent years, there has been a growing demand for environmentally friendly epoxides made from vegetable oils. Therefore, the use of materials from renewable resources, was implemented in this study with natural zeolite as a catalyst being chosen over synthetic zeolite because synthetic zeolite mostly consists of strong corrosive materials. The aims of this research to determine the effect of catalyst concentration on the relative conversion of oxirane (RCO). RCO was the highest at 30 min of the reaction for sunflower oil, being 72% at 80°C using a 0.25 g concentration of catalyst. Meanwhile, for palm oil, the highest RCO was only 52% at 80°C. Lastly, MATLAB software was used to develop a mathematical model for determination rate constant. In this model, the Runge–Kutta method of the fourth order was combined with genetic algorithm optimization to for development of kinetic model that best fitted with the experimental data.