Search Results (29)

Ulcerous lesions can arise in primary skin cancers and upon infiltration of the skin by malignant cells originating from other organs. These malignant fungating wounds are difficult to treat, and they cause pain, itching and malodor. Distressing malodor imposes a major burden on patients. The carrion odor of decaying tissue is—at least in part—due to the bacterial breakdown products cadaverine and putrescine. Here, we examined the binding of cadaverine, histamine, putrescine, spermidine and spermine to the preparation of micronized purified clinoptilolite-tuff (PCT) by relying on three radiolabeled tracers ([³H]cadaverine, [³H]histamine and [³H]spermidine). Binding was rapid, stable and of high capacity. The binding affinities were in the low µM range. Displacement experiments indicated that the binding sites were non-equivalent. These three properties combined to support effective binding for any given ligand in the presence of the expected, submillimolar concentrations of competing ligands. This was further verified by measuring the binding of [³H]cadaverine in the presence of wound drainage fluids. [³H]Cadaverine was effectively adsorbed by a wound dressing, into which purified clinoptilolite-tuff had been incorporated: the observed binding capacity of this wound dressing was consistent with its content of purified clinoptilolite-tuff. Based on these findings, we propose that purified clinoptilolite-tuff be further investigated as a means to control malodor emanating from chronic wounds. Full article

Increasing the biological effectiveness of probiotic preparations requires the development of new stable forms in the gastrointestinal tract. Live bacteria immobilized on a sorbent belong to the latest, fourth generation of probiotics, which ensures a prolonged effect. This study is devoted to developing a new method of preparing active lactobacilli on a natural mineral carrier, a tuff containing zeolite of the clinoptilolite group, which is among the most common authigenic silicate minerals that occur in sedimentary rocks and is known as a safe ion-exchange and adsorbing detoxicant. Among the characterized lactobacilli, strains of L. plantarum, L. acidophilus, and L. crispatus possessed a high level of acid formation and stability in gastrointestinal fluids. The protective effect of the clinoptilolite-containing tuff was registered when the samples were incubated in gastric juice. The optimal technological conditions for immobilization and lyophilization were determined, and the preservation of the viability and probiotic properties of bacteria was confirmed during 8 months of storage. The release of bacteria from the carrier occurred gradually over 12 h. The data obtained show how promising the new preparation is, combining the ability to detoxify harmful intestinal metabolites and the prolonged release of probiotics. Full article

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. Full article

The avoidance of allergen intake is crucial for persons affected by peanut allergy; however, the cross-contamination of food is common and leads to unpredictable consequences after the consumption of supposedly “safe” food. The aim of the present study was to eliminate harmful traces of peanut allergens from food using purified clinoptilolite-tuff (PCT)—a specially processed zeolite material. Analyses were performed using a peanut ELISA and a Coomassie blue (Bradford) assay. Mimicking conditions of the human gastrointestinal tract demonstrated a higher efficacy of PCT in the intestine (pH 6.8) than in the stomach (pH 1.5). Adsorption rates were fast (<2 min) and indicated high capacities (23 µg and 40 µg per 1 mg of PCT at pH 1.5 and pH 6.8, respectively). Allergenically relevant peanut protein concentrations were sorbed in artificial fluids (32 µg/mL by 4 mg/mL of PCT at pH 1.5 and 80.8 µg/mL by 0.25 mg/mL of PCT at pH 6.8) when imitating a daily dose of 2 g of PCT in an average stomach volume of 500 mL. Experiments focusing on the bioavailability of peanut protein attached to PCT revealed sustained sorption at pH 1.5 and only minor desorption at pH 6.8. Accompanied by gluten, peanut proteins showed competing binding characteristics with PCT. This study therefore demonstrates the potential of PCT in binding relevant quantities of peanut allergens during the digestion of peanut-contaminated food. Full article

Adsorptive, catalytic, and antibacterial properties of clinoptilolite-rich tuffs (ZT) are presented here. ZT transformed into Fe-containing ZT (Fe-ZT) removes various organic and inorganic anions from water. Fe-ZT, which contains selenium, is beneficial for growing Pleurotus ostreatus mushrooms. The fungi convert inorganic Se from Fe-ZT into a more useful organically bonded form. ZT and Fe-ZT as supplements retain nitrogen and potassium in sandy, silty loam and silty clay soils. ZT shows an affinity toward toxic metal cations, which are essential for cleaning contaminated water. The adsorption of atenolol, acetylsalicylic, and salicylic acid onto M-ZT (M–Cu²⁺, Mn²⁺, Ni²⁺, or Zn²⁺) from water solutions suggests that both the natures of M and pharmaceuticals have a significant impact on the adsorption mechanism and determine the adsorption capability of the ZT. ZT is an excellent carrier for ultrafine (2–5 nm) nano oxide particles, which have been shown to have catalytic activity in different chemical processes and photodegradation reactions of organic pollutants. ZT can also be transformed into SO₄-SnO₂-ZT, which is catalytically active as a solid acid. M-ZT is an effective carrier of valuable bacteria. Ag-ZT possesses beneficial bactericidal activity in disinfecting water and soil remediation. Full article

The migration of 32 elements from natural zeolitized tuffs from the Beli Plast and Golobradovo deposits (Bulgaria) was determined in ultrapure, tap, mineral, and coal mine waters in order to evaluate their desorption and adsorption properties. The tuffs are Ca-K-Na and contain clinoptilolite (90 and 78wt.%, respectively), plagioclase, sanidine, opal-CT, mica, quartz, montmorillonite, goethite, calcite, ankerite, apatite, and monazite. The desorption properties are best revealed during the treatment of ultrapure, tap, and mineral water, whereas the adsorption properties are best manifested in coal mine water treatment. The concentrations of Al, Si, Fe, Na, Mn, F, K, Pb, and U increase in the treated ultrapure, tap, and mineral water, while the content of K, Be, Pb, and F increase in the treated mine water. The tuffs show selective partial or complete adsorption of Na, Mg, Sr, Li, Be, Mn, Fe, Co, Ni, Cu, Zn, Al, Pb, U, and SO₄²⁻. They demonstrate the ability to neutralize acidic and alkaline pH. Sources of F are presumed to be clinoptilolite and montmorillonite. The usage of zeolitized tuffs for at-home drinking water treatment has to be performed with caution due to the migration of potentially toxic and toxic elements. Full article

Granular and powdery clinoptilolite tuff samples from Beli Plast, Eastern Rhodopes, Bulgaria, were coated with metal hydroxides (Fe, Al, Fe-Mg) by two-step alkalization. The prepared sorbents were tested for As(III) and As(V) uptake from a modeled water solution with an arsenic concentration of 44 μg/L. The granular sorbent was used in the sorption columns and showed a high efficiency of arsenic purification from slightly polluted waters. The calculated maximum sorption capacity for the optimal conditions is 32.9 μg/g. The adsorption proceeds according to the Langmuir model. The mechanism of adsorption is most likely inner-sphere complexation. The sorbents’ complete regeneration was achieved by NaOH treatment. The results of the experiments show good possibilities for obtaining water with an arsenic concentration ranging from below the limit of detection to 3.8 µg/L, which is a significantly lower value than the permitted value of 10 μg/L and close to the national environmental quality standard for shallow waters. The high efficiency shows Fe- or Mg,Fe-coated clinoptilolite sorbents. The sorbents are highly efficient in purifying 400 liters of water with an initial concentration of 44 mg/L of either arsenate or arsenite per 1 kilogram of sorbent at a rate of 2.4–2.0 L/h/kg. The powdered sorbents used in a batch system under “static” conditions showed a much higher adsorption capacity than the granular one. Such sorbents are more suitable for small quantities of water with a high concentration of arsenic. Full article

Acid mine drainage originates from mining waste, tailings and overburden being exposed to air and water; it is also observed in abandoned mines, characterized by high acidity and increased concentrations of sulfate and heavy metals. It is considered a notorious pollutant, mostly affecting superficial and ground water quality. Until 1977, Lavrion mines have been the heart of dynamic Greek mining and extractive metallurgy. The present paper discusses the possibility of using low-cost eco-friendly materials, i.e., natural and synthetic zeolites for the in situ rehabilitation of Lavrion mine soil. Na-P1 synthetic zeolite prepared from Meliti fly ash and two natural zeolites from Samos tuffs mostly containing clinoptilolite and mordenite, respectively, were employed. The results indicated that all three aluminosilicates alleviated two basic soil parameters closely correlated with fertility, i.e., high acidity and low CEC. Regarding toxic metals leaching, Na-P1 synthetic zeolite proved more efficient, reducing heavy metal contents in the leachates by 38%, 72%, 61%, 67%, 77% and 33% for Pb, Cd, Zn, Cu, Mn and Fe, respectively. This was attributed to both the increased pH and CEC values of the Na-P1 zeolite. Between the Samos zeolites, the richest in mordenite exhibited the better performance. Full article

Bisphenol A is a remarkable chemical compound as it has many applications, mainly in the plastics industry, but it also has toxic effects on the environment and human health. This article presents a comparative study regarding the adsorption of BPA on Active carbon and zeolitic tuff, ZTC. In this paper, the characterization of the zeolitic tuff, adsorbent, was carried out from an elemental and mineralogical point of view, and it noted the pore size and elemental distribution, using SEM, EDAX, and XRD analysis. The pore size varies from 30 nm to 10 µm, the atomic ratio is Si/Al ≥ 4, and 80% of the mineralogical composition represents Ca Clinoptilolite zeolites and Ca Clinoptilolite zeolites ((Na_1.32K_1.28Ca_1.72Mg_0.52) (Al_6.77Si_29.23O₇₂)(H₂O)_26.84). Moreover, a comparative study of the adsorption capacity of bisphenol A, using synthetic solutions on an activated carbon type—Norit GAC 830 W, GAC—as well as on Clinoptilolite-type zeolitic tuff—ZTC, was carried out. The experiments were carried out at a temperature of 20 °C, a pH of 4.11, 6.98, and 8.12, and the ionic strength was assured using 0.01 M and 0.1 M of KCl. The adsorption capacities of GAC and ZTC were 115 mg/g and 50 mg/g, respectively, at an 8.12 pH, and an ionic strength of 0 M. The Langmuir mathematical model best describes the adsorption equilibrium of BPA. The maximum adsorption capacity for both adsorbents increased with an increasing pH, and it decreased with increasing ionic strength. Full article

The Tevinskoye agate deposit is located in the North of the Kamchatka peninsula (Russia) and represented by agate-bearing Eocene basaltic and andesitic rocks of the Kinkilsk complex. Agate mineralization occurs in lavas and tuffs as amygdales, geodes, lenses and veins, which are the main sources of the resupply of coastal agate placers. The present study aimed to perform a comprehensive mineralogical, geochemical, and O-isotope investigation of amethyst-bearing agates, and to evaluate data concerning the origin of mineralization and the conditions for amethyst formation. Agates exhibit spectacular textures, with variation in the sequence of silica filling of amygdales and geodes. The mineral composition of the agates is mainly represented by micro- and macro-crystalline quartz, amethyst, length-fast and zebraic chalcedony, moganite, goethite, and clinoptilolite. Carbonate forms individual bands in the outer zones of some agates. The presence of small amounts of native copper, covellite, chalcopyrite and pyrite is a feature of these agates. Copper and iron mineralization are probably typomorphic features related to the host rock composition. The measured values of crystallite size (525–560 Å) and the high moganite content (up to 50%) of agate with amethyst are evidenced by the young age (~45 Ma) of agate-hosting rocks. Agate formation temperatures (21–229 °C) were calculated from the O-isotope composition of chalcedony (+19.6 to +25.5‰), quartz (+18.1 to +22.3‰), and amethyst (+18.2 to +21.5‰). The cold-water monophase fluid inclusions revealed in amethyst crystals suggest that the mineralizing fluids have low temperatures (<100 °C) and low salinity. Magnetite grains in host rock, together with goethite inclusions identified within the amethyst crystals, point to a change in redox conditions and the presence of iron in the agate-forming fluids, which entered the quartz lattice during crystallization and influenced the formation of the violet color. Full article

Iron deficiency-induced chlorosis is a widespread horti-/agricultural problem that can lead to massive crop failures, especially for plants growing on calcareous soils. The most effective agronomical practice to prevent plants from iron deficiency is to apply synthetic Fe-(chelate)-fertilizers to the soil. Because these compounds are usually not biodegradable and, therefore, may become soil contaminants, efficient and environmentally friendly solutions are needed. The present study investigates a novel approach to tackle chlorosis in plants using clinoptilolite-tuff as a carrier substrate for the natural Fe-siderophore ‘coprogen’. The combination of the two substances promises economic and ecological potential to be used as a fertilizer to prevent crop failures triggered by micro-nutritional shortages. Sorption and release experiments were performed in batch and column setups in order to understand the binding characteristics; analyses were carried out using ICP-MS, HPLC, XRD, and SEM, respectively. Results show the highest sorption capacity of coprogen (92.8%) and corresponding Fe (90.2%) on clinoptilolite-tuff at pH 4 within 30 min as well as the efficient release of coprogen at pH 8, mimicking alkaline soil conditions (88% of the sorbed coprogen is released from the tuff). The gained data suggest that coprogen is bound onto the clinoptilolite-tuff through surface-mediated sorption based on electrostatic interactions. Full article

The radionuclides of cesium (Cs) and strontium (Sr) are dangerous products of nuclear fission that can be accidentally released into wastewater. In the present work, the capacity of thermally treated natural zeolite (NZ) from Macicasu (Romania) to remove Cs⁺ and Sr²⁺ ions from aqueous solutions in batch mode was investigated by contacting different zeolite quantities (0.5, 1, and 2 g) of 0.5–1.25 mm (NZ1) and 0.1–0.5 mm (NZ2) particle size fractions with 50 mL working solutions of Cs⁺ and Sr²⁺ (10, 50, and 100 mg L⁻¹ initial concentrations) for 180 min. The concentration of Cs in the aqueous solutions was determined by inductively coupled plasma mass spectrometry (ICP-MS), whereas the Sr concentration was determined by inductively coupled plasma optical emission spectrometry (ICP-OES). The removal efficiency of Cs⁺ varied between 62.8 and 99.3%, whereas Sr²⁺ ranged between 51.3 and 94.5%, depending on the initial concentrations, the contact time, the amount, and particle size of the adsorbent material. The sorption of Cs⁺ and Sr²⁺ was analyzed using the nonlinear form of Langmuir and Freundlich isotherm models and pseudo-first-order (PFO) and pseudo-second-order (PSO) kinetic models. The results indicated that the sorption kinetics of Cs⁺ and Sr²⁺ on thermally treated natural zeolite was described by the PSO kinetic model. Chemisorption dominates the retention of both Cs⁺ and Sr²⁺ by strong coordinate bonds with an aluminosilicate zeolite skeleton. Full article

The clarity of the beer is essential to its marketability and good consumer approval. Moreover, the beer filtration aims to remove the unwanted constituents that cause beer haze formation. Natural zeolite, an inexpensive and widespread material, was tested as a substitute filter media for diatomaceous earth in removing the haze constituents in beer. The zeolitic tuff samples were collected from two quarries in Northern Romania: Chilioara, in which the zeolitic tuff has a clinoptilolite content of about 65%, and the Valea Pomilor quarry, containing zeolitic tuff with a clinoptilolite content of about 40%. Two-grain sizes, <40 and <100 µm, from each quarry were prepared and thermally treated at 450 °C in order to improve their adsorption properties and remove organic compounds and for physico-chemical characterization. The prepared zeolites were used for beer filtration in different mixtures with commercial filter aids (DIF BO and CBL3) in laboratory-scale experiments, and the filtered beer was characterized in terms of pH, turbidity, color, taste, flavor, and concentrations of the major and trace elements. The results showed that the taste, flavor, and pH of the filtered beer were generally not affected by filtration, while turbidity and color decreased with an increase in the zeolite content used in the filtration. The concentrations of Na and Mg in the beer were not significantly altered by filtration; Ca and K slowly increased, while Cd and Co were below the limits of quantification. Our results show that natural zeolites are promising aids for beer filtration and can be readily substituted for diatomaceous earth without significant changes in brewery industry process equipment and protocols for preparation. Full article

The geological nature of the territory of the Republic of Cuba has favoured the formation of large and varied deposits of volcanic tuffs enriched by various species of zeolites. Today, new zeolite deposits continue to be discovered in the country. This work aims to present the results of a study carried out in an unexplored area that is located approximately 1.2 km east of the Loma Blanca deposit, outside the mining operation limits. To carry out this research and to establish a qualitative comparison between both sample populations, four samples were taken from the study area, and another four were taken from the Loma Blanca deposit. The characterisation of the samples was performed by XRD, SEM, and XRF. The pozzolan quality was determined by the pozzolanicity test (PT) and quality chemical analysis (QCA). Finally, a study of the mechanical strength (MST) was performed at 7, 28, and 90 days, using mortar specimens made with PC/ZT: 75–25% and PC/ZT: 70–30%, respectively. The results of the studies using XRD, SEM, and XRF indicated that both groups of samples had a similar complex mineralogical composition, consisting mainly of mordenite and clinoptilolite accompanied by secondary phases such as quartz and amorphous materials in the form of altered glass. The pozzolanicity test showed that both the samples from the study area and those from the Loma Blanca deposit behaved like typical pozzolans, which is a trend that can be seen in the high values of mechanical strength to compression up to 72 MPa for the PC/ZT: 75–25% formulation and 66 MPa for the PC/ZT: 70–30%. The results obtained establish that the zeolite varieties detected in the study area are similar to those of the Loma Blanca deposit, which could have a positive impact on the increase in current reserves, especially for manufacturing pozzolanic cements with properties that contribute to the preservation of the environment. Full article

Various gluten-related diseases (celiac disease, wheat allergy, gluten sensitivity) are known and their incidence is growing. Gluten is a specific type of plant storage protein that can impair the health of gluten-prone persons following consumption, depending on the origin. The most severe effects are induced by wheat, barley, and rye. The only treatment is based on the absolute avoidance of those foods, as even traces might have severe effects on human well-being. With the goal of binding gluten impurities after ingestion, an in vitro setting was created. A special processed kind of zeolite, purified clinoptilolite-tuff (PCT), was implemented as an adsorber of gluten derived from different origins. Zeolites are known for their excellent sorption capacities and their applications in humans and animals have been studied for a long time. Tests were also performed in artificial gastric and intestinal fluids, and the adsorption capacity was determined via a certified validated method (ELISA). Depending on the kind of gluten source, 80–130 µg/mg of gluten were bound onto PCT. Hence, purified clinoptilolite-tuff, which was successfully tested for wheat, barley, and rye, proved to be suitable for the adsorption of gluten originating from different kinds of crops. This result might form the basis for an expedient human study in the future. Full article