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The development of materials for uremic toxin removal is under continuous research. In this work, a natural zeolite (clinoptilolite) was modified using tartaric acid through two different methods: conventional reflux heating and ultrasound energy. The resulting materials were used as an adsorbent material for the removal of uremic toxins such as urea, creatinine, and uric acid. In the uremic toxin removal study, it was observed that the material modified using ultrasound for 100 min had the highest removal values (74.49%, 40.31%, and 51.50% for urea, creatinine, and uric acid, respectively), while unmodified zeolite removed 30.57%, 18.07%, and 22.84% of the same toxins. The best results for conventional heating modification were 67.08%, 31.97%, and 32.39%, respectively. Therefore, acid group incorporation considerably improved the adsorption properties of the clinoptilolite. Regarding adsorption kinetics, it was found that the pseudo-second-order model better described the behavior of all the modified materials. Equilibrium adsorption data were adjusted to the Langmuir and Freundlich models. The Freundlich model (multilayer adsorption) described urea adsorption, while the Langmuir model (monolayer adsorption) described creatinine and uric acid. [ABSTRACT FROM AUTHOR]

In recent years, researchers are looking for ways to reduce the amount of sulfur in kerosene. Therefore, desulfurization of kerosene is considered an important commercial and environmental process. Among the hard and complicated methods available for the desulfurization process, natural zeolites can be a suitable alternative for the desulfurization of oil products due to their economic efficiency, biocompatibility, and natural abundance of oil reserves. In this research, natural zeolite (clinoptilolite) was modified with CuO nanoparticles and used as adsorbent for desulfurization of kerosene. The effect of important parameters such as adsorbent dose, pH of solution and initial adsorbate concentration were investigated. Results indicated the optimum conditions as follows: dose of adsorbent 2 g, pH 10 and the adsorbate dose 200 ppm. Results showed that the modified adsorbent is a suitable, low-cost and good efficiency for the desulfurization process of kerosene. [ABSTRACT FROM AUTHOR]

An isotherm of water vapor adsorption on clinoptilolite was constructed within the framework of the thermodynamic approach in the range of relative air humidities from 0 to 1 at physically acceptable parameters of the system. The isotherm has a characteristic inflection point in the region of average humidity; due to this, it can be classified as an isotherm of the fourth type, which has a hysteresis loop at certain values of the system parameters. It is concluded that the resulting model isotherm describes adsorption in mesoporous materials, such as ion exchangers used in agrochemical practice, and is fully consistent with the experimental adsorption isotherm of this type. [ABSTRACT FROM AUTHOR]

Adsorption properties of sulfurous compounds in natural gases have been studied using clinoptilolite type zeolite catalyst with rich deposits in Azerbaijan. As a result, it was determined that the use of modified clinoptilolite is the most effective based on experimental evidence for the adsorption of H2S, COS and RSH on modified clinoptilolite and NaX zeolite. Based on H2S and COS adsorption heats in modified clinoptilolite, the optimal temperature of regeneration was determined at 250 °C. This is the value of the rate of desorption of sulfur compounds (H2S and COS) from NaX zeolite at 320 °C, determined in industry, in other equal conditions. Thermally modified clinoptilolite is shown to have the best absorption and protective properties. [ABSTRACT FROM AUTHOR]

Due to its remarkable surface properties, natural clinoptilolite-tuff interacts with a variety of biochemical, pharmaceutical, chemical, and microbiological entities, including human viruses. In the present work, the virucidal activity of purified clinoptilolite-tuff (PCT) was investigated using a variety of viruses, differing in their structure and composition. Influenza A virus, Herpes Simplex virus, Rhinovirus, and Parvovirus were chosen to represent enveloped and non-enveloped viruses with RNA and DNA genomes. Beside human viruses, Canine Parvovirus and bacteriophages T4 and MS2 were used to represent animal and bacterial viruses, respectively. The virucidal activity of PCT was quantified by examining the residual viral activity on susceptible cell lines upon incubation with PCT. A wide range of antiviral efficiencies was observed, ranging from up to 99% for Herpes Simplex virus to no activity for Rhinovirus and both bacteriophages. This study reveals that the virucidal potential of PCT is not universal and depends on a complex set of factors including virus structure and medium composition. The environmental and medical implications of this research are discussed for uses such as wastewater treatment or wound healing. [ABSTRACT FROM AUTHOR]

Investigations have shown the traces of antibiotics in surface water, groundwater, wastewater treatment plants, and drinking water. However, conventional wastewater treatment is not entirely effective for vancomycin degradation. Advanced oxidation is one of the most widespread methods of antibiotic degradation in aqueous media. Vancomycin was quantified by high-performance liquid chromatography. The Response Surface Methodology (RSM) based on Central Composite Design (CCD) was used to explore and optimise the effect of the independent variables on vancomycin degradation. Independent variables were as follows: pH (3–11), vancomycin concentration (15–75 mg/L), TiO2–clinoptilolite (25–125 mg in 250 mL reactor volume), the temperature (25–45°C), and the reaction time (15–75 min). The validity and adequacy of the model were confirmed by the corresponding statistics (F–value = 111.5, correlation coefficient R2 = 0.98, adjusted R2 = 0.97, and prediction R2 = 0.95). The vancomycin degradation efficiency was 97% under optimal conditions (pH = 5, vancomycin concentration = 30 mg/L, TiO2-clinoptilolite content = 50.2 mg in a 250 mL reactor volume, temperature = 32.24°C, and reaction time = 50.9 min). This process followed the zero-order reaction kinetics model (R2 = 0.98), and the removal rate of Total Organic Carbon (TOC) under optimal conditions was 56%. The results indicated that supporting TiO2 on clinoptilolite particles could increase the photocatalytic properties. [ABSTRACT FROM AUTHOR]

BACKGROUND: A material of natural origin, clinoptilolite, was modified with selected metals in order to obtain a catalyst for the conversion of xylose – the main component of the hemicellulose fraction present in lignocellulosic biomass – to selected carboxylic acids. RESULTS: The starting material without modification (0‐parent), the hydrogen form (0‐hydrogen) of zeolite and zeolite after hierarchization with hydrochloric acid (0‐dealuminated) were used. Iron, copper and cobalt ions were introduced as active centers using the sonication technique. The catalytic process was carried out in a pressure autoclave for 2 h at a temperature of 220 °C. Compounds such as formic acid with a yield of 91% (0‐parent) and lactic acid with a yield of 66.1% (Fe‐hydrogen) were obtained. Conclusion: The catalytic processes carried out using xylose lead to the obtaining of a mixture of carboxylic acids: lactic acid, pyruvic acid and formic acid. An important role here is played by the presence of iron as an active site, which leads to the transformation of xylose into lactic acid by dehydration, and the presence of Lewis and Brønsted active sites. In the case of formic acid, which has never been reported in publications on a similar topic, the starting zeolite without modification contributed to its preparation. It is possible that the content of alkali metals contributed to its preparation along with the coupling of the oxidation reaction of the intermediate product, because of the presence of small amounts of iron, which are present in the natural material. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

The present study reports the surfactant modification of Bolivian natural zeolite with hexadecyltrimethylammonium bromide (HTDMA-Br) for the adsorption of hexavalent chromium Cr (VI) anions from water. The surfactant-modified natural zeolite was characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption/desorption isotherms, and Fourier-transform infrared spectroscopy (FTIR) to analyze the effect of its modification with HTDMA-Br and to verify its charge on the zeolite surface. We report a maximum adsorption capacity of 17 mg/g of Cr (VI) anions, surpassing the findings of some of the previous investigations on surfactant-modified natural zeolites of different geological origins. The analysis of the equilibrium data described the Cr (VI) anions adsorption by Langmuir isotherm and the pseudo second-order kinetic model. In addition, thermodynamics revealed an exothermic adsorption. Furthermore, anion exchange, electrostatic attraction, and chemical reduction were indicated to be dominating sorption mechanisms by X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) characterization techniques. [ABSTRACT FROM AUTHOR]

The wastewater effluent is responsible for the major ecological impact of the dairy sectors. To avoid the negative consequences of heavy metal pollution on the ecosystem, creative, affordable, and efficient treatment methods are now required before the effluent flows into the surrounding area. This study was aimed at assessing the effectiveness of three different adsorbents for Cd+2 and Cr+6 ions from wastewater effluents of dairy farms, including chitosan (CS), clinoptilolite zeolite (CZ), and chitosan/clinoptilolite zeolite (CS/CZ) composite. The adsorption kinetics of the CS/CZ composite were established using the effects of the key variables (pH, agitation speed, adsorbent concentrations, and contact durations). The removal (%) and adsorption capacities, qe (mg/g), were calculated using the data from the adsorption kinetics. Wastewater samples (n = 60) were collected from the wastewater effluents of five farms. Cd+2 and Cr+6 ion concentrations in all collected samples were determined. Following the CS/CZ composite creation, it was characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (X-RD), and Fourier-transform infrared spectrum (FT-IR). The CS/CZ composite had an adsorption capacity of 92.4 and 96.5 mg/g for both Cd+2 and Cr+6 ions at a concentration of 2.0 g/100 ml, respectively, while the CZ adsorption capacities for the two ions were 87.5 mg/g and 61.0 mg/g, respectively, at 4.0 g/100 ml concentration. The CS was achieved at 55.56 mg/g and 33.3 mg/g, respectively, at the same concentration. The efficiency of heavy metal removal was enhanced by increasing adsorbent concentration, agitation speed, and contact duration. Using CS/CZ composite at 2.0 g/100 ml concentration, 180 min of contact time, and 300 rpm agitation speed, the greatest removal efficiencies for Cd+2 and Cr+6 ions (96.43 and 98.75%, respectively) were demonstrated. [ABSTRACT FROM AUTHOR]

The purpose of this work was to study the catalytic activity for the conversion of methanol into formaldehyde, dimethyl ether, methyl formate, dimethoxymethanane of zeolite catalysts - based on natural clinoptilolite and its modified Co2+, Cu2+, Mo2+, Cr2+ forms (Cl-X). The yield was 14.3% in the naturalclinoptilolite, 27.8% in the Co2+-modified sample, and 37.3% in the Cu2+-modified sample, correspondingly. The introduction of relatively small amounts of Co2+ and Cu2+ cations into the catalyst led to an increase in the activity of the catalysts. The effect of partial pressure of CH3OH on the yield of DME was studied (maximum yield of 37.3%, mol. DME is achieved at the ratio CH3OH:O2 = 3:1). The decrease in the reaction temperature from 523 to 423 K led to an increase in the yield of DMM, and the formation of dimethyl ether and methyl formate increased with an increase in temperature to 623 K. [ABSTRACT FROM AUTHOR]

This study delves into the acid modification of natural zeolite clinoptilolite, focusing on the identification of acid site types and their catalytic activity in the Brønsted acid‐catalyzed acetalization of benzaldehyde with 1,3‐butanediol. Following calcination, the samples underwent acidification via ammonium‐ion exchange, resulting in approximately 45 % of the clinoptilolite cations being exchanged with ammonium ions. The investigation evaluates the structural, morphological, and textural alterations induced by this modification using XRD, FTIR, and nitrogen adsorption‐desorption measurements. Ammonia‐temperature‐programmed desorption (NH3‐TPD) analysis confirms the presence of medium to strong acidic protons, highlighting the acidity of the modified samples. Employing 27Al and 29Si magic‐angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy elucidated changes in the state and coordination of aluminum post‐sample activation. Specifically, the 27Al MAS NMR spectra indicate a partial dealumination, evidenced by the emergence of 5 and 6‐fold coordinated aluminum. Moreover, 29Si MAS NMR measurements tracked variations in the Si/Al ratio. The study probes the nature of these sites, their influence on catalytic activity, and the synergistic interplay between Brønsted acid sites and 5‐fold coordinated aluminum. The results showcase that the prepared acidic natural clinoptilolite catalysts augment acidity and porosity, fostering promising implications for catalytic applications. [ABSTRACT FROM AUTHOR]

Understanding the thermal properties of zeolites is crucial for their industrial applications. This study explores the thermal stability and dehydration process of clinoptilolite using high-temperature X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Clinoptilolite's thermal decomposition was monitored from 25 °C to 1200 °C, with results analyzed based on its crystal structure. Principal components analysis (PCA) of the DRIFT spectra indicated progressive water removal and dehydration upon heating, leading to the formation of hydrogen bonds. Thermogravimetric analysis (TGA) revealed a two-step endothermic weight loss: initially, physically adsorbed water was lost up to 100 °C, followed by the removal of tightly bound water and hydroxyl groups until 800 °C. Clinoptilolite remained the dominant phase up to 800 °C, after which albite and cristobalite took over. Rietveld refinement showed that the sample initially contained 70% clinoptilolite, 24% albite, and 6% cristobalite. Above 800 °C, clinoptilolite disappeared, leaving 93% albite and 7% cristobalite. FT-IR spectra changes due to water loss were evident: drying of adsorbed water occurred up to 75 °C and minimal changes were observed from 75 °C to 135 °C, followed by further dehydration until 240 °C. Complete dehydration was confirmed by the disappearance of OH stretching vibration bands by 395 °C, consistent with TGA findings. [ABSTRACT FROM AUTHOR]

The use of natural zeolite clinoptilolite to reduce the leaching rate of potentially toxic elements such as Cd, Pb, and Mn in soil from mine tailings was studied. Soil from the surroundings of the mine El Bote in Zacatecas, Mexico, was analyzed, and the zeolite was characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, and nitrogen physisorption. An ammonium-exchange method for the zeolite was employed. Leaching experiments using packed columns with polluted soil and zeolite mixtures were carried out and the effect of the pH of the carrier solutions was studied. Incorporation of zeolite in the soil achieved a beneficial increase in pH, from 5.03 to 6.95. The concentration of Cd and Mn was reduced when zeolite was present in the column and the ammonium-modified zeolite with ammonia also enhanced the concentration reduction of metallic species in leachates in a range of 28 to 68%. The first-order model best fits the experimental data, suggesting that the leaching rate is controlled by concentration difference between the liquid and the soil matrix. These results demonstrate the potential for using natural zeolite clinoptilolite to reduce the leaching rate of potentially toxic elements in soil from mine tailings. [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HA) has great bioactive potential in bone tissue engineering (BTE). However, the high crystalline stability of synthetic HA restricts its in-vivo bioresorbability which extends the healing time of bone defects. This study investigates doping HA with biocompatible Clinoptilolite (CLP) mineral rich in silicate and other biomimetic ions (Na+, K+, Ca+2, Mg+2 etc.). Sol-gel-based CLP doped HA nanoceramics are aimed to be exploited as bone filler substitutes with biomimetic morphology, composition, and improved biocompatibility and bioactivity. The pure and CLP (5%, 10% and 20%) doped HA ceramics were synthesised by sol-gel method to provide molecular level interactions of ions and sintered at different temperatures (800 °C, 950 °C, and 1100 °C). Morphological analyses by SEM and S-TEM showed biomimetic nano rod-like HA particles are attached to dispersed CLP sheets. Sintering of composite ceramics led to a cell-friendly interconnected porous microstructure even at 1100 °C, where the pure HA had a compact non-porous structure. The Ca/P ratio of CLP-doped HA samples was lower than the stoichiometric HA which indicates a partial reduction of stability that is supposed to induce bioresorption capacity. Cytotoxicity tests by WST-8 with Saos-2 cell lines showed that CLP addition into HA has significantly improved cell viability. The HA-CLP nanoceramics are expected to promote bone regeneration due to cell-friendly microstructure and biomimetic composition which can be supported by further in-vivo clinical studies. [Display omitted] [ABSTRACT FROM AUTHOR]

Ion exchange is the reversible exchange of ions in which there is no significant change in the solid structure. Zeolites are aluminosilicates with a defined structure, including cavities occupied by cations and water molecules, both with great freedom of movement, which makes cation exchange possible. In this study, small-pore zeolites chabazite (CHA) and clinoptilolite (CLI) were ion-exchanged with potassium. Then, the samples were characterized by N2 isotherms at 77 K, CO2 adsorption microcalorimetry at 298 K, and water vapor isotherms at 313 K. A mathematical model was applied to evaluate the adsorption kinetics for water vapor uptakes. Textural analysis showed that the ion exchange with potassium decreased the porosity of both zeolites, but CO2 microcalorimetric data showed that these samples had higher CO2 adsorption enthalpy, indicating a greater sorbate-sorbent interaction as compared to the pristine zeolites. Uptake rate curves suggest water diffusion is not appreciably altered after ion exchange. Interestingly, despite the larger size of K+ cations as compared to Na+, effective diffusion time constant is on order of magnitude larger for the potassium-loaded CLI very likely due to the leaching of other contaminants upon ion-exchange. [ABSTRACT FROM AUTHOR]

Zeolitic materials enriched in phosphorus and nitrogen, with a pronounced content for this last element, were obtained from natural clinoptilolite (CLI) treated with ammonium hydrogenphosphate (DAP) and urea. The interaction of phosphorus and nitrogen species retained on CLI was analyzed using different research methods. FTIR spectra showed the presence of NH4+, PO43− and urea on CLI. The retention of ammonium involves both ion-exchange in clinoptilolite, and adsorption. Phosphate is retained by adsorption, and it can be incorporated into an electrical double layer with accompanying cations including NH4+. The FTIR bands of the amino group of urea appear to be shifted relative to their location in the urea spectrum. This is associated with weakening of N–H bond from amino group due to its interaction with the clinoptilolite framework via hydrogen bonding. The urea is arranged on the zeolite surface, which is consistent with SEM observations and elemental (N and P) mapping by STEM. As a result, the surface area and micropore volume of these materials, treated with DAP and urea, decrease with respect to those modified with DAP alone. Accordingly, the release studies showed that the subsequent delivery of phosphorus species occurs in a delayed mode. These materials have great potential to be used as slow-release nutrient fertilizers for crop plants. They have a significant amount of nitrogen available on their surface, allowing plants to easily assimilate it early in their growing cycle. Zeolitic matrix leads to obtain materials at low-cost for massive applications, efficient use of nutrients and environmental benefits. [ABSTRACT FROM AUTHOR]

Neurodegenerative diseases (NDs), characterized by progressive degeneration and death of neurons, are strongly related to aging, and the number of people with NDs will continue to rise. Alzheimer's disease (AD) and Parkinson's disease (PD) are the most common NDs, and the current treatments offer no cure. A growing body of research shows that AD and especially PD are intricately related to intestinal health and the gut microbiome and that both diseases can spread retrogradely from the gut to the brain. Zeolites are a large family of minerals built by [SiO4]4− and [AlO4]5− tetrahedrons joined by shared oxygen atoms and forming a three-dimensional microporous structure holding water molecules and ions. The most widespread and used zeolite is clinoptilolite, and additionally, mechanically activated clinoptilolites offer further improved beneficial effects. The current review describes and discusses the numerous positive effects of clinoptilolite and its forms on gut health and the gut microbiome, as well as their detoxifying, antioxidative, immunostimulatory, and anti-inflammatory effects, relevant to the treatment of NDs and especially AD and PD. The direct effects of clinoptilolite and its activated forms on AD pathology in vitro and in vivo are also reviewed, as well as the use of zeolites as biosensors and delivery systems related to PD. [ABSTRACT FROM AUTHOR]

The heterogeneous Fenton process is a promising technology for the removal of persistent pollutants in aqueous media. However, the development of solid catalysts that do not leach iron particles from the structure, that can be easily recovered and used in multiple reaction cycles is still a challenge. Therefore, the objective of this study was to propose the design of a new heterogeneous Fenton catalyst supported on pre-treated clinoptilolite nanoparticles with HNO3, with magnetic recovery. The zeolite was reduced to nanoparticles using a ball mill and then pre-treated with nitric acid in a reflux system. Iron particles were fixed on the support through the wet impregnation method, and the material was subjected to physicochemical characterization. The catalytic activity was tested in the degradation of the textile dye Reactive Blue (RB250) under batch conditions, and different effects were evaluated. The results showed that the modifications on the clinoptilolite support enhanced its specific surface area and pore volume, while Mössbauer results confirmed that the applied synthesis process resulted in excellent magnetic catalysts that can be easily recovered. The 15Fe/CPGT catalyst completely degraded the contaminant in 60 min, following pseudo-second-order kinetics (k = 1.14 L g−1.min−1). The reuse tests indicated the ease of removing the catalyst particles through magnetism and high catalytic performance even after eleven consecutive runs. Toxicological tests and chemical parameters such as TOC and COD confirmed the reduction of effluent toxicity. Finally, the developed magnetic Fenton catalyst is a material with high catalytic potential for application in the Fenton-like process. [ABSTRACT FROM AUTHOR]

This work is concerned with classification and study of the composition and properties of hydrothermal zeolites from the Yagodninskoe deposit, (Kamchatka) which were formed in volcanic rocks. The study involved X-ray phase analysis and X-ray fluorescence, optical and scanning electron microscopy. We determined specific syrface AREA the pore size distribution, as well as cation exchange capacity in zeolites. The study resulted in the identification of four main rock types at the deposit: the original unaltered perlites, zeolites rock, zeolitized tuffs, as well as poorly zeolitized tuff breccias. The Content of zeolite group minerals reaches 70%. The minerals mostly include clinoptilolite and, to a lesser degree, mordenite, stilbite, and heulandite. The zeolites are of the alkaline type, with the cation exchange capacity equal to 205.9 mg-equi/100 g. It has been found that these zeolites were mostly formed from perlites and tuff breccias. It is pointed out that the Yagodninskoe zeolites are high quality minerals, and make a promising object of further exploration. [ABSTRACT FROM AUTHOR]

Negative temperature coefficient (NTC) materials are usually based on ceramic semiconductors, and electrons are involved in their transport mechanism. A new type of NTC material, adequate for alternating current (AC) applications, is represented by zeolites. Indeed, zeolites are single charge carrier ionic conductors with a temperature-dependent electrical conductivity. In particular, electrical transport in zeolites is due to the monovalent charge-balancing cations, like K+, capable of hopping between negatively charged sites in the aluminosilicate framework. Owing to the highly non-linear electrical behavior of the traditional electronic NTC materials, the possibility to have alternative types of materials, showing linearity in their electrical behavior, is very desirable. Among different zeolites, natural clinoptilolite has been selected for investigating NTC behavior since it is characterized by high zeolite content, a convenient Si/Al atomic ratio, good mechanical strength due to its compact microstructure, and low toxicity. Clinoptilolite has shown a rapid and quite reversible impedance change under heating, characterized by a linear dependence on temperature. X-ray diffraction (XRD) has been used to identify the natural zeolite, to establish all types of crystalline phases present in the mineral, and to investigate the thermal stability of these phases up to 150 °C. X-ray photoelectron spectroscopy (XPS) analysis was used for the chemical characterization of this natural clinoptilolite sample, providing important information on the cationic content and framework composition. In addition, since electrical transport takes place in the zeolite free-volume, a Brunauer–Emmett–Teller (BET) analysis of the mineral has also been performed. [ABSTRACT FROM AUTHOR]

The study aimed to assess the safety of using modified natural clinoptilolite as a food additive for mammals. Any potential adverse impacts of altered natural clinoptilolite on the regular physiological processes of animals were evaluated. Sixty male ICR laboratory mice, aged approximately 6–8 weeks, were randomly assigned to control and experimental groups. Both groups underwent a 45-day testing period, during which the experimental group was given rodent food mixed with 12.5% modified natural clinoptilolite from the Beli Plast deposit, Bulgaria. Sampling was carried out on days 0, 15, 30 and 45, with each time point providing samples for morpho-physiological and haematological studies, the oxidative stress on the base of malondialdehyde (MDA) and glutathione (GSH) measurements in liver and kidney so as the assessment of gene toxicity via the micronucleus test. All animals used in the experiment survived until the end of the study, gained weight and showed good activity and vital signs. The mice supplemented with clinoptilolite showed 21% higher body weight gain compared to the control group. Furthermore, there were no established signs of gene toxicity, pathological changes in the levels of oxidative stress and haematological parameters. These results suggest that using clinoptilolite as a food supplement does not lead to observable toxicities and even improves growth performance. Owing to its elevated sorption potential, this method is appropriate for purging the mammalian organism of toxins, with negligible adverse outcomes. [ABSTRACT FROM AUTHOR]

The flammability properties of polymers and polymeric composites play an important role in ensuring the safety of humans and the environment; moreover, flame-retardant materials ensure a greater number of applications. In the present study, we report the obtaining of polypropylene (PP) composites contain a mixture of two green flame retardants, lignin and clinoptilolite, by melt extrusion. These additives are abundantly found in nature. Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), mechanical properties, scanning electron microscopy–energy dispersive X-ray spectroscopy (SEM-EDS), cone calorimetry, UL-94, and carbonized residues analysis were carried out. TGA analysis shows that PPGFR-10 and PPGFR-20 compounds presented better thermal stability with respect to PP without flame retardants. The conical calorimetric evaluation of the composites showed that PPGFR-10 and PPGFR-20 presented decreases in peak heat release rates (HRRs) of 9.75% and 11.88%, respectively. The flammability of the composites was evaluated with the UL-94 standard, and only the PPGFR-20 composite presented the V-0 and 5VB classification, which indicates good flame-retardant properties. Additives in the polymer matrix showed good dispersion with few agglomerates. The PPGFR-20 composite showed an FRI value of 1.15, higher percentage of carbonized residues, and UL-94 V-0 and 5VB rating, suggesting some kind of synergy between lignin and clinoptilolite, but only at high flame-retardant concentrations. [ABSTRACT FROM AUTHOR]

The use of natural zeolite clinoptilolite in preparing photocatalysts and its function in photocatalysis are discussed in this review. The importance of advanced oxidation processes (AOPs) and the potential of heterogeneous photocatalysis in removing environmental pollutants are emphasized. The review focuses on the synergistic effects of clinoptilolite with semiconductors (TiO2, ZnO, CuO, SnO2, and NiO) to prepare stable and active photocatalysts, highlighting recent advancements in this field. It explores clinoptilolite's structural characteristics, highlighting its microporous nature, adaptable framework, and improved textural properties due to acid and alkali treatments. Particle size, crystal phase, and calcination temperature are three key synthesis parameters that affect photocatalytic activity and are highlighted in the discussion of these parameters and their methods. A discussion is held regarding the processes and mechanisms of photocatalytic degradation of different organic compounds under varying irradiation conditions, including UV, visible, and ambient sunlight. Clinoptilolite is vital in improving supported semiconductor oxides' photocatalytic efficiencies, which aid in pollutant degradation and environmental remediation. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article on the removal of emerging organic pollutants in drinking water and watershed water using zeolite mineral composite photocatalysts. The correction involves fixing citation numbers for references throughout the manuscript. The corrected references cover topics such as photocatalysis, wastewater treatment, heavy metal removal, and pollutant degradation. The document is a compilation of research articles and reviews on zeolites and their applications in environmental remediation, catalysis, and adsorption. The articles discuss the synthesis, characterization, and photocatalytic activity of zeolite-based materials, as well as their use in removing heavy metals and organic pollutants from water. The research highlights the potential of zeolites as efficient and sustainable materials for environmental applications. Additionally, the document includes a collection of scientific articles focusing on the use of clinoptilolite zeolite as a photocatalyst for degrading organic pollutants in wastewater. The articles explore the photocatalytic activity of different catalysts supported on clinoptilolite nanoparticles and investigate the degradation of various organic compounds. The studies demonstrate the potential of these photocatalysts for removing organic pollutants from wastewater and advancing water treatment technologies. Furthermore, the document provides a list of scientific articles discussing the photocatalytic degradation of pollutants like antibiotics, herbicides, dyes, and other organic compounds. The articles examine different photocatalysts and their effectiveness under simulated solar or visible light. They also discuss the use of materials like zeolite, titanium dioxide, [Extracted from the article]

Methyl tert-butyl ether (MTBE), an underground water contaminant, has the potential to cause serious health and environmental issues, necessitating its removal before any use of the water. This research investigated the adsorption behavior of MTBE on natural nanoporous adsorbents, namely bentonite clay and clinoptilolite, using an experimental batch system. The optimum conditions for removing MTBE from water were determined by investigating the impact of adsorption parameters, such as the solution pH, temperature, time, MTBE concentration, and the dosage of bentonite clay and clinoptilolite. The removal efficiency of bentonite and clinoptilolite was found to be 98.09% and 97.44%, respectively, with adsorption capacity values of 2220 and 2002.159 mgg−1, respectively. The experimental results were accurately modeled by utilizing the pseudo-second-order equation and the Langmuir model for adsorption kinetics and isotherms, respectively. The thermodynamic analysis, including determination of the change in free energy, enthalpy and entropy under standard condition, indicated an exothermic and spontaneous adsorption process for MTBE utilizing the natural nanoporous adsorbents. At the end, the results demonstrated that both bentonite and clinoptilolite are effective natural adsorbents for removing MTBE from aquatic environments. [ABSTRACT FROM AUTHOR]

The environmental concern related to excessive ammonium in water bodies necessitates efficient and cost-effective removal techniques. This study investigated the modification of natural zeolite collected from the Tanggamus district of Lampung Province, Indonesia, with ethylenediaminetetraacetic acid (EDTA) to enhance its performance for ammonium adsorption from aqueous solution. The modified and natural zeolites were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), N2 adsorption-desorption isotherm, and scanning electron microscopy (SEM). Results indicated that the modification did not cause significant structural changes but increased the mesoporosity of the zeolites, which was beneficial for ammonium adsorption. The adsorption studies revealed that the EDTA modified zeolites consistently outperformed the natural zeolite and that the adsorption process was exothermic in nature. The Langmuir and Freundlich isotherm models fit the adsorption data well, indicating that the adsorption process occurs on both homogenous and heterogeneous surfaces. Thermodynamic studies confirmed that the adsorption process was exothermic and that the EDTA modification increased the spontaneity of the ammonium adsorption process. Overall, this study highlights the potential of EDTA-modified zeolites as an effective material for ammonium removal from aqueous solutions.

Negative temperature coefficient (NTC) materials are usually based on ceramic semiconductors, and electrons are involved in their transport mechanism. A new type of NTC material, adequate for alternating current (AC) applications, is represented by zeolites. Indeed, zeolites are single charge carrier ionic conductors with a temperature-dependent electrical conductivity. In particular, electrical transport in zeolites is due to the monovalent charge-balancing cations, like K+, capable of hopping between negatively charged sites in the aluminosilicate framework. Owing to the highly non-linear electrical behavior of the traditional electronic NTC materials, the possibility to have alternative types of materials, showing linearity in their electrical behavior, is very desirable. Among different zeolites, natural clinoptilolite has been selected for investigating NTC behavior since it is characterized by high zeolite content, a convenient Si/Al atomic ratio, good mechanical strength due to its compact microstructure, and low toxicity. Clinoptilolite has shown a rapid and quite reversible impedance change under heating, characterized by a linear dependence on temperature. X-ray diffraction (XRD) has been used to identify the natural zeolite, to establish all types of crystalline phases present in the mineral, and to investigate the thermal stability of these phases up to 150 °C. X-ray photoelectron spectroscopy (XPS) analysis was used for the chemical characterization of this natural clinoptilolite sample, providing important information on the cationic content and framework composition. In addition, since electrical transport takes place in the zeolite free-volume, a Brunauer–Emmett–Teller (BET) analysis of the mineral has also been performed.

Abstract This study focuses on CO2 capture by pressure swing adsorption (PSA), with modified clinoptilolite as the adsorbent. Natural clinoptilolite is modified by roasting, by acid pickling, by a combination of acid pickling and roasting, and by ion exchange. Modification by acid pickling–roasting and by ion exchange are found to give the highest CO2 adsorption capacities, of 730 mL/g and 876.7 mL/g, respectively. It is found that regeneration of clinoptilolite by a combination of vacuum desorption and heating enables recovery of as much as 89% of its previous CO2 adsorption capacity. To examine the CO2 adsorption capacity of clinoptilolite when applied to mixed gas, a simulated coking exhaust containing 12% CO2 and 4% O2 is used, and it is found that ion exchange modified clinoptilolite achieves a CO2 removal efficiency of 92.5%. A BET test reveals that acid pickling–roasting and Na+ modification enhance the porosity of clinoptilolite, thereby improving its adsorption capacity. This work demonstrates the feasibility of applying modified clinoptilolite as an effective adsorbent for CO2 capture, providing a promising tool for dealing with greenhouse gases.

Two methods of using permanent NdFeB magnets and their impact on the sorption of radionuclides (Cs, Sr, Co) by clinoptilolite and composite sorbents based on zeolites are discussed. Sorption processes were considered under dynamic conditions with liquid circulation. No changes in sorption processes were observed when magnetic treatment was applied to solutions containing radionuclide ions. The natural zeolite clinoptilolite and synthetic zeolites NaX and NaA were considered at this stage. In the work, clinoptilolite from the Sokirnitske deposit in the Zakarpattia region of Ukraine was used. Ukraine possesses significant deposits of clinoptilolite. When magnets were applied to the sorbent during the sorption process, an increase in cobalt sorption of 10% was observed for clinoptilolite, and strontium sorption increased by 17%. The influence of a magnet on clinoptilolite is due to the presence of iron ions in the composition of clinoptilolite. The iron content ranges from 0.9% to 2.5%. The composition of the composite sorbent included clinoptilolite and synthetic zeolite NaX. No increase in radionuclide sorption was observed for composite sorbents, likely due to the presence of clinoptilolite in the sorbent composition and the corresponding iron content. The analytical part of the study was carried out using the PIXE (Particle Induced X-ray Emission) method on the analytical nuclear-physics complex "Sokil." The energy range of the accelerator was 200-2000 keV. The complex made it possible to carry out all the main methods of analysis using ion beams. The targets were placed in the exit, at the Chamber for PIXE. To excite the atoms of cesium, strontium, and cobalt a proton beam with an energy of Ер≈1400 keV was used.

Chromium is the main constituent of the tanning salts used by tanneries for processing skins into leather, and considered as a pollutant in the effluents that this industry discharge. The present study aimed to evaluate the removal of chromium and other pollutants in effluents from the tanning industry applying the natural zeolite Neonite. Neonite is a commercially available zeolite, that was acquired from NEONITE S.A. Neonite was characterized through FTIR and XRD, identifying clinoptilolite as its main component. Treatment was applied to samples of real effluents from the tanning stage or chromium bath (CB) and a composite effluent (CE), an experimental design was carried out for each effluent. The designs correspond to 32 factorial designs, variables tested were the Neonite dosage (NE) measured in g/L, stirring time (StT) expressed in minutes and the pH of the sample, and the response variable was the Residual Chromium Content (RCC). Statistical analysis was performed through R-software version 4.2.3 and included Box-Cox transformation and ANOVA to determine the main effects and the behavior of the response variable in relation to the applied model and its optimization by response surface. In CB, a removal above 95 % was obtained for RCC, with optimization values at 32 g/L of NE and pH 7. In the CE, a removal of more than 98 % was obtained for RCC and values higher than 60 % for BOD, COD, TSS and Fats, being the optimal conditions 4.73 g/L of NE and 12.17 minutes of StT. These results demonstrate that the application of Neonite for the removal of chromium and other pollutants from tanning industry effluents has a great potential.

Simple Summary: In the last decades, the number of available chemical pesticides for pest control has been dramatically reduced due to their possible negative effects on human health and the environment. Therefore, there is an immediate necessity to explore alternative products to chemical pesticides for pest control, with natural zeolites (zeolitic rocks) being among the potential options. The olive fruit fly, Bactrocera oleae Gmelin (Diptera: Tephritidae), is one of the most harmful pests of olives in Mediterranean countries and worldwide. In this study, we evaluated the oviposition-deterrent effect of a natural zeolite on the olive fruit fly under different temperatures and relative humidity conditions. The tested natural zeolite was highly effective in deterring egg laying in B. oleae females under all tested conditions. These findings are poised to advance our understanding of sustainable and eco-friendly strategies for pest control in olive orchards, presenting opportunities for the development of targeted interventions that align with both environmental conservation and effective agricultural practices. In recent years, the number of available chemical pesticides has been dramatically reduced, urging the need for the discovery of alternatives to chemical pesticide products such as, among others, natural zeolites (zeolitic rocks). We determined the mineralogical and chemical composition of a specific and continuous layer of zeolitic rock sample (ZeotP) from Petrota, Evros, Greece, and evaluated its oviposition-deterrent effect on the olive fruit fly Bactrocera oleae Gmelin (Diptera: Terphritidae). The tested natural zeolite contained 70 wt. % clinoptilolite, 18 wt. % amorphous material, 7 wt. % feldspars, 4 wt. % cristobalite, and 1 wt. % quartz. We tested the oviposition-deterrent effect of ZeotP mixed or not with an emulsifier adjuvant, NU-FILM-P®, in water and applied it to the surface of olive fruits. The ZeotP oviposition-deterrent effect on the olive fly was very high under a series of tested temperatures (17 °C, 20 °C, 25 °C, and 30 °C) and RHs (23%, 33%, 55%, 75%, and 94%). In addition, the ZeotP residual deterrent effect after equable water spraying was high, like the respective effect of the pyrethroid insecticide Decis® (deltamethrin). Our results may contribute to the effective control of the olive fruit fly using an alternative to chemical pesticides: natural zeolite (zeolitic rocks) products. [ABSTRACT FROM AUTHOR]

One of the most challenging problems for people around the world is the lack of clean water. In the past few decades, the massive discharge of emerging organic pollutants (EOPs) into natural water bodies has exacerbated this crisis. Considerable research efforts have been devoted to removing these EOPs due to their biotoxicity at low concentrations. Heterogeneous photocatalysis via coupling clay minerals with nanostructured semiconductors has proven to be an economical, efficient, and environmentally friendly technology for the elimination of EOPs in drinking water and watershed water. Natural zeolite minerals (especially clinoptilolites) are regarded as appropriate supports for semiconductor-based photocatalysts due to their characteristics of having a low cost, environmental friendliness, easy availability, co-catalysis, etc. This review summarizes the latest research on clinoptilolites used as supports to prepare binary and ternary metal oxide or sulfide semiconductor-based hybrid photocatalysts. Various preparation methods of the composite photocatalysts and their degradation efficiencies for the target contaminants are introduced. It is found that the good catalytic activity of the composite photocatalyst could be attributed to the synergistic effect of combining the clinoptilolite adsorbent with the semiconductor catalyst in the heterogeneous system, which could endow the composites with an excellent adsorption capacity and produce more e−/h+ pairs under suitable light irradiation. Finally, we highlight the serious threat of EOPs to the ecological environment and propose the current challenges and limitations, before putting the zeolite mineral composite photocatalysts into practice. The present work would provide a theoretical basis and scientific support for the application of zeolite-based photocatalysts for degrading EOPs. [ABSTRACT FROM AUTHOR]

This study focuses on CO2 capture by pressure swing adsorption (PSA), with modified clinoptilolite as the adsorbent. Natural clinoptilolite is modified by roasting, by acid pickling, by a combination of acid pickling and roasting, and by ion exchange. Modification by acid pickling–roasting and by ion exchange are found to give the highest CO2 adsorption capacities, of 730 mL/g and 876.7 mL/g, respectively. It is found that regeneration of clinoptilolite by a combination of vacuum desorption and heating enables recovery of as much as 89% of its previous CO2 adsorption capacity. To examine the CO2 adsorption capacity of clinoptilolite when applied to mixed gas, a simulated coking exhaust containing 12% CO2 and 4% O2 is used, and it is found that ion exchange modified clinoptilolite achieves a CO2 removal efficiency of 92.5%. A BET test reveals that acid pickling–roasting and Na+ modification enhance the porosity of clinoptilolite, thereby improving its adsorption capacity. This work demonstrates the feasibility of applying modified clinoptilolite as an effective adsorbent for CO2 capture, providing a promising tool for dealing with greenhouse gases. [ABSTRACT FROM AUTHOR]

Volcanic tuffs rich in chabazite zeolites have been extensively examined for their potential to enhance soil properties and increase fertilizer efficiency, both in their natural state and when enriched with nitrogen (N). However, there is a scarcity of data regarding their utilization in acidic sandy soil, particularly when used alongside organic fertilizers. This paper presents the findings of a 50-day laboratory incubation study that investigated the dynamics of N pools in an acidic sandy-loam agricultural soil treated with various N sources. These sources included urea, N-enriched chabazite zeolite tuff, and pelleted composted manure applied at a rate of 170 kg N/ha. Additionally, the N sources were tested in combination with chabazite zeolite tuff mixed into the soil to assess its role as a soil conditioner. The results revealed distinct behaviours among the tested N sources, primarily impacting soil pH and N dynamics. Soil fertilized with manure exhibited slow N mineralization, whereas N-enriched zeolite displayed a more balanced behaviour concerning net NO3−-N production and NH4+-N consumption. Both N-enriched zeolite and urea temporarily altered the soil pH, resembling a "liming" effect, while pelleted manure facilitated a prolonged shift towards neutral pH values. Considering the water adsorption capacity of zeolite minerals, caution is advised when adjusting water content and employing combustion methods to measure soil organic matter in zeolite-treated soil to avoid potential inaccuracies. In summary, N-enriched chabazite zeolite tuff emerged as a valuable N source in acidic sandy-loam soil, offering a promising alternative to synthetic fertilizers and showcasing a sustainable means of N recycling. [ABSTRACT FROM AUTHOR]

In this study, natural clinoptilolite was treated with HCl, HNO3, and C2H2O4 at various concentrations (0.1, 0.5, and 1.0 M) at different temperatures (60, 70, and 80 °C) and treatment times (2, 3, and 4 h). The hydrogen adsorption capacity of natural clinoptilolite increased from 0.446 to 3.255 mmol/g after treating with 0.5 M HNO3 at 80 °C for 2 h. The correlation of the newly produced textural and structural properties with hydrogen adsorption ability is explained by characterizing the modified clinoptilolites using X-ray fluorescence (XRF), X-ray diffraction (XRD), nitrogen adsorption/desorption isotherms, and temperature programmed desorption of ammonia (NH3-TPD) measurements. The results show that the hydrogen adsorption capacity of modified clinoptilolites is associated with both the quantity and strength of the strong acid sites, in addition to the enhanced surface area and micropore volume. The hydrogen adsorption data for natural and acid-treated clinoptilolite samples at 77 K obeyed the Freundlich isotherm model. [ABSTRACT FROM AUTHOR]

In this study, the effects of two different ammonium-exchange methods to improve the ammonia (NH3) gas adsorption of raw clinoptilolite (CLN) from Gördes (Türkiye) was investigated. The first method involved direct modification of CLN by 0.5 or 1.0 M NH4NO3 solutions at 80°C for 4 and 8 h followed by calcination. In the second method, CLN was converted to the Na+ form prior to modification with ammonium nitrate and calcination under the same conditions. Both methods yielded H+ forms of CLN through the removal of exchangeable cations without damaging the crystal structure. Ammonia adsorption isotherms were determined at 298 K for a total of eight different H+ forms synthetized using both methods. The Na-1.0-8h CLN sample with the highest NH3 adsorption capacity obtained using the second method was selected as the parent CLN. In addition, to determine the effects of doping different cations into the structure on the NH3 adsorption properties of the selected parent CLN sample, cation-exchange processes were carried out using 0.5 and 1.0 M NaNO3, KNO3, Ca(NO3)2 and Mg(NO3)2 solutions at 80°C for 4 h. The raw and modified CLNs were characterized using X-ray diffraction, X-ray fluorescence, scanning electron microscopy and N2 adsorption analyses. Cation-exchanged samples with a wide range of NH3 adsorption capacities (3.61–4.93 mmol g–1) were compared with other zeolites from the literature. [ABSTRACT FROM AUTHOR]

Chromium is the main constituent of the tanning salts used by tanneries for processing skins into leather, and considered as a pollutant in the effluents that this industry discharge. The present study aimed to evaluate the removal of chromium and other pollutants in effluents from the tanning industry applying the natural zeolite Neonite. Neonite is a commercially available zeolite, which was acquired from NEONITE S.A. Neonite was characterized through FTIR and XRD, identifying clinoptilolite as its main component. Treatment was applied to the samples of real effluents from the tanning stage or chromium bath (CB) and a composite effluent (CE), an experimental design was carried out for each effluent. The designs correspond to 32 factorial designs, the variables tested were the Neonite dosage (NE) measured in g/L, stirring time (StT) expressed in minutes and the pH of the sample, and the response variable was the residual chromium content (RCC). Statistical analysis was performed through Rsoftware version 4.2.3 and included Box-Cox transformation and ANOVA to determine the main effects and the behavior of the response variable in relation to the applied model and its optimization by response surface. In CB, a removal above 95% was obtained for RCC, with optimization values at 32 g/L of NE and pH 7. In the CE, a removal of more than 98% was obtained for RCC and values higher than 60% for BOD, COD, TSS and Fats, being the optimal conditions 4.73 g/L of NE and 12.17 minutes of StT. These results demonstrate that the application of Neonite for the removal of chromium and other pollutants from tanning industry effluents has a great potential. [ABSTRACT FROM AUTHOR]

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Clinoptilolite, with its structural peculiarities (ion-exchange and adsorbent properties), is an excellent candidate for direct use and various modifications. In this study, we explored the effect of ion exchange and the particle size of clinoptilolite on Raphanus sativus seed germination, plant growth, physiological and biochemical characteristics of plants. Plants were grown, for three consecutive runs, on non-modified clinoptilolite, 0.9–2.5 mm (C-2.5) and 2.5–5.0 mm (C-5.0); clinoptilolite fractions modified with ion exchange with ammonium (CNH4-2.5 and CNH4-5.0); and potassium (CK-2.5 and CK-5.0) ions. Our data revealed that ion exchange with ammonium increased water-holding capacity, while potassium exchange decreased the water-holding capacity of the substrates irrespective of their particle size. The positive effect of small fractions ion-exchanged clinoptilolite (CNH4-2.5 and CK-2.5) on seed germination, during the third run, was established. The small clinoptilolite fractions favored root crop production, particularly in CK-2.5 plants only during the first run. Substantial positive effect on the content of total carbohydrates and polyphenols especially during the third run was established in plants grown on potassium-exchanged clinoptilolite. Our findings support the future exploration of clinoptilolite as a suitable substrate for plant growth in space and ground-based facilities for space-oriented experiments. [ABSTRACT FROM AUTHOR]

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are environmentally persistent, bioaccumulating, and toxic compounds that have attracted global attention. It is challenging to reduce the residual concentrations of these compounds to safe discharge limits. In this study, batch experiments were performed to evaluate natural clinoptilolite and clinoptilolites modified (MC) with cetylpyridinium chloride (CPC-MC), didodecyldimethylammonium bromide (DDAB-MC), hexadecyltrimethylammonium bromide (HDTMA-MC), and tetramethylammonium chloride (TMA-MC) as cost-effective aqueous PFAS adsorbents. The removal capacities of the adsorbents for the majority of the PFASs decreased in the following order: DDAB-MC > CPC-MC ≫ modified natural clinoptilolite with hexadecyltrimethyl ammonium bromide (HDTMA-MC) ≫ modified natural clinoptilolite with tetramethylammonium chloride (TMA-MC) ≈ natural clinoptilolite modified with NaCl (NC). In particular, CPC-MC and DDAB-MC reduced PFASs concentration in 50 μg/L by up to 98% for perfluorooctane sulphonate. Within 30 min, CPC-MC (30.5 μg/L) and DDAB-MC (32.1 μg/L) met the PFOS water quality criterion of 36 μg/L in inland surface waters. Both adsorbents met this criterion at the highest solution volume (40 mL) and 0.125 g/L (solid-to-liquid ratio of 1:8). PFASs with short hydrocarbon chains competed more for adsorption. PFASs with sulphonate functional groups were also adsorbed more than carboxyl groups in single- and multi-PFAS solutions. The modified surfaces of clinoptilolites controlled PFAS adsorption through hydrophobic and electrostatic interactions. PFAS removal with surfactant-modified clinoptilolites is cost-effective and protects aquatic environments by using surplus natural materials. [ABSTRACT FROM AUTHOR]

Sorption-luminescence method for ytterbium determination based on natural Transcarpathian clinoptilolite was proposed. The optimal luminophore preparation conditions are Yb(III) sorption on the precalcined at 300 °C clinoptilolite and further treatment of clinoptilolite-Yb(III) samples with 1-(2-pyridylazo)-2-naphthol and ethonium solution at pH 8.5. A sample of luminophore clinoptilolite-Yb(III)-PAN-ethonium was heated at 50°С. The linear calibration range of Yb(III) concentration with the detection limit of 5 ng·mL−1 is within 12.5–1000 ng·mL−1. The proposed method can be used for ytterbium determination in the presence of many rare earths. The method gives recoveries from 92.5% to 103% and RSD from 3.1% to 5.8% determination of ytterbium. [ABSTRACT FROM AUTHOR]

The cutting-edge field of nanomedicine combines the power of medicinal plants with nanotechnology to create advanced scaffolds that boast improved bioavailability, biodistribution, and controlled release. In an innovative approach to performant herb nanoproducts, Sideritis scardica Griseb and clinoptilolite were used to benefit from the combined action of both components and enhance the phytochemical's bioavailability, controlled intake, and targeted release. A range of analytical methods, such as SEM-EDX, FT-IR, DLS, and XDR, was employed to examine the morpho-structural features of the nanoproducts. Additionally, thermal stability, antioxidant screening, and in vitro release were investigated. Chemical screening of Sideritis scardica Griseb revealed that it contains a total of ninety-one phytoconstituents from ten chemical categories, including terpenoids, flavonoids, amino acids, phenylethanoid glycosides, phenolic acids, fatty acids, iridoids, sterols, nucleosides, and miscellaneous. The study findings suggest the potential applications as a promising aspirant in neurodegenerative strategy. [ABSTRACT FROM AUTHOR]

As a result of the research of the reaction of 3,4-dihydro-2H-pyrano-dimethylacetylene carbinol (also with its Csp-substituted derivatives) of iodo-alkylation on clinoptilolite in the presence of (NaK)4CaAl6Si30O72 and crystalline iodine, 3-iodine-2-[(2-methyl-4- organyl-but-3-in-2-yl)oxy]oxane was prepared. This method of preparation of heterocyclic compounds allows the reaction to be carried out in the absence of solvents, which reduces the amount of reagents and allows obtaining a product with high purity and high yield (67.5%). It was established that the latter under the conditions of the Kucherov reaction turn into heterocyclic compounds. Thus, effective regioselective methods for the synthesis of dioxin derivatives have been developed. This fact is probably related and is obviously explained by the intramolecular cyclization of the resulting intermediate-ketohydroxyester, i.e. tandem hydrolysis of C–I and hydration of C≡C bonds of the reaction products. The yield of 2-benzyl-3,3-dimethylhexahydro-4aH-piran[2,3-b][1,4]dioxin-2-ol is higher than that of structural analogues. It should also be noted that the synthesized compounds have an increased reactivity, and are rich in nucleophilic centers. Based on experimental data, it was established that the compounds obtained in this way are stable and do not undergo hydrolysis. Some physicochemical properties of the synthesized compounds were given, their composition and structure were confirmed by elemental analysis data, and all synthesized compounds were identified by IR and NMR spectroscopy. [ABSTRACT FROM AUTHOR]

To enhance the nitrogen utilization efficiency of fertilizers, we developed a novel slow-release fertilizer hydrogel through free radical polymerization, incorporating lignin-containing cellulose nanofiber (LCNF), clinoptilolite (CL), urea, and acrylic acid (AA)-co-acrylamide (AAm) polymer. Various analytical techniques were utilized to examine the structure, swelling, and release behaviors of the fabricated hydrogels with varying LCNF concentrations. The results indicated that the addition of 10% LCNF led to a decrease in water absorption from 72.44 g g−1 to 24.04 g g−1. However, re-swelling was significantly enhanced, with a reduction in re-swelling capacity loss from 32.91% to 23.52%. Concurrently, water retention capacity notably increased from 18.03% to 39.20%. The hydrogel containing 10% LCNF exhibited a slower urea release over 30 days. The kinetic studies revealed that the swelling and urea release behaviors align well with the second-order kinetics model and the Peppas-Sahlin model, respectively. In summary, the developed LCNF/CL/(AA-co-AAm)/urea hydrogel nanocomposites present a novel strategy for the future production and utilization of slow-release fertilizers in agricultural and horticultural fields.

The Clinoptilolite and Mobil Composition of Matter No. 41 (MCM-41), represented by natural inorganic and synthetic inorganic materials, respectively, were supported by chitosan and used as solid adsorbents for CO2 capture. Studying different parameters like temperature and pressure revealed that the highest adsorption capacities were observed at 25 ᵒC and 9 bar with values of 8.90 mmol/g for MCM-41@Chitosan and 9.01 mmol/g for Clinoptilolite@Chitosan. According to the isotherm study results, when Clinoptilolite@Chitosan was used as a solid adsorbent, the experimental results best fit both the Langmuir model and Freundlich model. For MCM-41@Chitosan, the Sips model exhibited the highest R2 value. The results of the Kinetic study demonstrated that the CO2 capture by MCM-41@Chitosan and Clinoptilolite@Chitosan involved physisorption, best aligned with the Elovich model described the CO2 adsorption process Furthermore, the thermodynamic study of both adsorbents indicated that as the temperature increased, the highest adsorption capacity decreased. Therefore, the CO2 capture process by both solid adsorbents was exothermic. The mass transfer parameters of Clinoptilolite@Chitosan and MCM-41@Chitosan were determined within a single-component system. Clinoptilolite@Chitosan exhibited a mass flux of 0.3488 mol/m2.s, a diffusion coefficient of 3.07 × 10−4 m2/s, and a mass transfer coefficient for CO2 molecules in the gas phase of 9.790 m/s. Meanwhile, MCM-41@Chitosan demonstrated a mass flux of 1.41 × 10−4 mol/m2.s, diffusion coefficient of 0.1517 m2/s and mass transfer coefficient of 0.1661 m/s.