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Nano metal oxides (NMOs), with their unique physico-chemical properties and low toxicity, have become a focus of research in heterogeneous catalysis. Their distinct characteristics, which can be tailored based on size and structure, make them highly efficient catalysts. NMOs have the potential to significantly contribute to the degradation of numerous environmental pollutants through photolytic decomposition. This work comprehensively analyzes the synthesis, catalytic performance, and applications of photocatalytically active metal oxides, specifically titanium, zinc, copper, iron, silver, tin, and tungsten oxides. The primary objective is to demonstrate how the effectiveness of photocatalytic processes can be enhanced and optimized by incorporating metals, non-metals, and metalloids into their structure and forming heterostructures. Furthermore, the aim is to understand the underlying process of photocatalytic oxidation thoroughly. Photocatalysis, a promising approach in advanced oxidation processes, has garnered significant interest in these fields. [ABSTRACT FROM AUTHOR]

Due to the development of resistance to antimicrobial agents, bacterium Acinetobacter baumannii is nowadays a leading cause of nosocomial outbreaks. Clinically relevant A. baumannii outside hospital settings including natural soils affected by human waste represents a public-health risk for humans and animals. The aim of this study was to investigate the potential of metal-loaded zeolites to eliminate viable A. baumannii from artificially contaminated natural soils. A. baumannii isolate was subjected to the activity of natural zeolitised tuff (NZ) and Cu-modified (CuNZ) or Ag-modified zeolite (AgNZ) in wet, slightly acidic terra rossa and slightly alkaline red palaeosol. A. baumannii survived in terra rossa and red palaeosol supplemented with 1 wt% of NZ for seven days and four months, respectively. The addition of 1 wt% of CuNZ to terra rossa and red palaeosol shortened the survival of A. baumannii to three and 14 days, respectively. The addition of 0.1 wt% of AgNZ to both soils resulted in complete removal of viable A. baumannii within 1 h of contact, while the total native heterotrophic bacterial counts remained high. Since AgNZ is prepared with a simple modification of cost-effective and environmentally friendly natural zeolite, it is a promising material for the remediation of soils contaminated with pandrug-resistant A. baumannii.

The use of natural zeolite – clinoptilolite, to protect wheat grain from storage insects within environmentally-friendly storage techniques can lead to the presence of small amounts of zeolite residues in flour. This study investigated the influence of as-received zeolite clinoptilolite (Z) and sodium-rich clinoptilolite (NaZ) in wheat dough on the dough rheological properties. Zeolites were added to dough at 0.5-1.5 wt.% flour basis level, which is a range expected to remain in the grain (flour) after treatment to control storage pests. The effects were studied in two types of wheat, conventional (Triticum aestivum) and spelt (T. aestivum spp. spelta) because they initially differ in rheological properties. NaZ was used to discern whether the presence of increased concentration of Na+ in the zeolite was able to exert a higher strengthening effect as compared to as-received zeolite (Z). NaZ exerted the highest dough strengthening effect which was mainly reflected as decreased dough softening and increased water absorption. The fact that the presence of NaZ was the most effective factor in improving the dough rheological profile suggested that the presence of movable cations in the zeolite lattice might have a pronounced role in the mechanism by which zeolite affects dough behaviour.

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]

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. [ABSTRACT FROM AUTHOR]

Environmental protection and sustainable agricultural production require the use of inexpensive and environmentally acceptable soil supplements. Objectives of this study were to investigate the influence of the addition of the natural zeolite – clinoptilolite (NZ) and its iron(III)-modified form (FeZ) on the potassium and nitrate leaching from sandy, silty loam and silty clay soils. The zeolites were added in two amounts: 0.5 (FeZ) and 1.0 wt. % (NZ and FeZ). The experiments were carried out in columns organized in eight experimental systems containing unamended (control specimens) and amended soils. The concentration of K+ and NO3–N in the leachates was monitored during 7 days. The obtained results indicate that the K+ and NO3–N leaching mainly depends on the soil type and pH of the soil. The NZ and FeZ addition has the highest impact on the K+ retention in the acidic sandy soil. The highest NO3–N retention is obtained with FeZ in acidic silty loam soil. The K+ leaching kinetics for all the studied soils follow the Avrami kinetics model with the parameter n < 1. This study demonstrates that NZ and FeZ can be a good soil supplement for the K+ retention for all studied soils and in the NO3–N retention for silty loam and silty clay soils. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 172018]

The clinoptilolite-rich tuff (NZ) from Zlatokop deposit (Vranjska Banja, Serbia) has been studied as a nitrogen carrier for grass production. Mechanism of binding ammonium cations present in water solutions by NZ has been examined as well as possibility of adsorption of ammonia released in fresh cattle manure during its fermentation. The NH4+ binding from solutions proceeds via an ion-exchange process which follows the pseudo-second-order kinetics. Adsorption isotherms studied at 298-318 K follow the Freundlich isotherm equation. The NZ readily adsorbs ammonia liberated from manure and an addition of 10 wt.% of NZ to manure can preserve up to 90% of ammonia. The potential benefit of this effect has been examined in greenhouse pot experiments with the Italian ryegrass (Lolium multiflorum, var. Macho) using three different types of soil (silty, clayey and sandy). The zeta potential measurements show that stability of their colloidal dispersions differs mutually and that addition of the NZ differently affects the stability and nitrogen cycling. All results indicate that NZ can be applied in grass production. [Projekat Ministarstva nauke Republike Srbije, br. 172018 and Norwegian Programme in Higher Education, Research and Development HERD]

The multidrug resistant bacteria Acinetobacter baumannii cause serious hospital infections. Commercial poly(vinyl chloride) (PVC) used for endotracheal tubes was modified in order to obtain the composite with antibacterial effect towards clinical isolate of A. baumannii ST145. The composites were prepared by addition of different amounts of copper-containing zeolite tuff (CuZ) and by successive impregnation with D-Tyrosine (D-Tyr) solution. The composites which were obtained by addition of CuZ (CuZ-PVC) only did not exhibit antibacterial effect. The impregnation of the CuZ-PVC by D-Tyr resulted in an antibacterial effect which is explained by a synergistic effect of CuZ and D-Tyr. Rheological tests confirmed that the modification of PVC by CuZ does not affect its processability and reformability. [Projekat Ministarstva nauke Republike Srbije, br. 172018]

In this paper the process of the copper (II) sulphate monohydrate from copper (II) sulphate pentahydrate (also known as a Blue vitriol or Bluestone) production was analyzed. Copper (II) sulphate pentahydrate is one of the most important copper salts which has been known since the ancient Egyptians. In the nineteenth century its application as a fungicide was discovered which provoked wide industrial production. Molecule of the copper (II) sulphate pentahydrate is a crystalohydrate with five water molecules linked by chemical bonds to a molecule of the copper (II) sulphate. Copper (II) sulphate exists as a series of compounds that differ in their degree of hydratation. The anhydrous form is a pale green or gray-white powder, whereas the pentahydrate (CuSO4•5H2O), the most commonly encountered salt, is bright blue. In order to obtain copper (II) sulphate monohydrate from copper (II) sulphate pentahydrate four water molecules need to be removed. To determine the optimum temperature and time required for the removal of four water molecules from a molecule of pentahydrate in this work thermogravimetric (TGA) analysis was performed. Thermogravimetric (TGA) analysis - dehydration of copper (II) sulphate pentahydrate is done using simultaneous TG-DSC thermal analyzer DTG-Q600 SDT from TA Instruments. Analyzes was carried out for two type of samples, the sample containing particles of the average diameter equal to 0.17 mm and the particles of the average diameter 0.5 mm. In addition, fluidization and drying curve was determined using a semi-industrial fluidization column. On top, the industrial fluidization column aimed to produce 300 tones per month of copper (II) sulphate monohydrate was designed. Material and energy calculations were performed using software packages Simprosys 3.0 and SuperPro Designer 5.1. Simprosys 3.0 is a software package designed for the modeling and simulation of a drying process as well as for 20 different unit operations. SuperPro Designer 5.1 facilitates modeling, evaluation and optimization of different industrial processes including drying. These softwares were applied for the calculation of the air flow rate, heat exchange and for the scoping of a dryer.

In this work, different metal oxides (MO) supported on two types of zeolites: 1) natural clinoptilolite (NZ) and 2) synthetic zeolite, ZSM-5 were prepared and tested as catalysts in the fast pyrolysis of hardwood lignin. NZ was modified with the CaO and MgO by a simple two steps procedure consisting of an ion exchange reaction and a subsequent calcination at 773 K. The synthetic ZSM-5 was modified with several MO species (Ni, Cu, Ca, Mg) by a wet impregnation and calcination at 873 K. Тhe prepared catalysts were characterized by X-ray diffraction analysis (XRD), scanning electron microscopy and energy dispersive X-ray analysis (SEM/EDS) and measurement of specific surface area (BET method). Acid sites were characterized and quantified by pyridine (py) absorption using Fourier transform infrared spectroscopy (FTIR). The catalysts exhibit catalytic activity depanding on modification, reaction temperature and of the MO contents. The highest yield of useful phenol in bio-oil was obtained with NiO/ZSM-5 (34.8 wt.%) which exhibits the highest specific surface area and the highest concetration of Brönsted and Lewis acid sites. The studied catalysts did not increase significantly the content of polycyclic aromatic hydrocarbons (PAHs) and heavy compounds compared to non-catalytic experiment. [Projekat Ministarstva nauke Republike Srbije, br. 172018]

The natural zeolitic tuff from the Zlatokop mine (Vranjska Banja deposit) has been investigated as a starting material for obtaining a low cost adsorbent for the removal of nitrate from water media. The tuff riched with zeolite - clinoptilolite was modified by simple procedures by several oxides: iron(III), manganese(IV) and magnesium in order to make clinoptilolite surface accessible for binding the nitrate ions. The obtained oxide-modified zeolite samples were characterized by scanning electron microscopy and energy dispersive X-ray analysis (SEM/EDS), powder X-ray diffraction (PXRD), infrared spectroscopy (FTIR) and by measurement of specific surface area. The effects of the adsorbent dosage (0.5, 1.0, 1.5 and 2.0 g), temperature (25, 35 and 45 °C) and initial nitrate concentration (C0= 100, 200 and 300 mg dm-3) on the binding efficiency were also studied. For all adsorbents the efficiency increases with temperature. The type of oxides effects the adsorption mechanism and Fe(III) oxide modified zeolite exhibits the best binding ability. For this adsorbent the adsorption kinetics was studied and found that it is best represented by the pseudo-second-order model. [Projekat Ministarstva nauke Republike Srbije, br. 172018]

The aim of this work is an investigation of the possible application of Serbian natural zeolitic tuff ("Igroš Vidojević" deposit, Brus) for improvement of the spring water quality. Concentration of magnesium in spring waters in Raska area (in southeast Serbia) is grater then 100 mg/dm3 and is unsuitable for everyday consumption. The experiments includied investigation of fluid-mechanics tests of the zeolite particles with diameters of 1.5 mm, 4 mm and 6 mm in a column with diameter of 65 mm and magnesium adsorption/desorption experiments in the column with a diameter of 110 mm. The results showed that using sodium enriched zeolite bed and using optimal fluid-mechanics parameters, the concentration of magnesium in the spring water can be decreased below the maximum allowed concentration of 50 mg/dm3. [Projekat Ministarstva nauke Republike Srbije, br. OI-172022, OI-172-018, IP-451-03-00605/2012-16/143]

Many efforts have been devoted to produce green materials and technology to prevent and minimize the adverse effects on the environment and human health caused primarily by population growth and industrial progress. Over the past years, the use of zeolites has attracted considerable attention as both an economically and environmentally friendly option. Zeolites are crystalline, hydrated aluminosilicates with an open-framework structure. Unique structural features make them very useful ion-changers, adsorbents and catalysts. The catalytic use of zeolites has expanded from traditional use in the petrochemical industry and refineries to use in the catalytic degradation of various environmental pollutants and the synthesis of fine chemicals. In recent times, progress on the use of zeolites has been achieved in biomass conversion to fuels and valuable industrial bio-based chemicals. This review highlights the recent advances in the catalytic application of clinoptilolite (CLI), the most abundant and explored natural zeolite. The main goal of the review is to give the current state of CLI applications and insights into CLI catalytic performance, which opens possibilities for a variety of applications. [ABSTRACT FROM AUTHOR]

3-methylaminopropylamine (MPA) has been studied as a structure-directing agent (template) in the synthesis of open-framework phosphate-based materials. The influence of temperature, molar ratio of reactants, crystallization time and presence of fluoride ions on the crystallization of aluminophosphate, transition metal-substituted aluminophosphate [transition metal - Mn(II), Cr(III) and Co(II)] and zincophosphate has also been investigated. MPA exhibits the templating role and in all as-synthesized crystalline products and it is entrapped in an inorganic lattice interacting with the framework via hydrogen or/and electrostatic interactions. According to detailed thermal analysis the type of interactions seems to be crucial for thermal behaviour of MPA and also for the thermal stability of the organic-inorganic crystal system. Structural analysis suggested that the formed crystalline structures have no mutual structural analogy. This indicates that precise role of the organic (guest) component in nucleation process for the open-framework phosphates (host) is very complex as well as the nucleation process itself. [Projekat Ministarstva nauke Republike Srbije, br. 172018]

The thermal degradation of cetyltrimethylammonium bromide (CTMAB) inside the mesoporous SBA-3 was studied under non-isothermal conditions. There are two distinct and complex kinetic processes which partly overlap, each consisting of one dominant and three minor individual processes. The two dominant processes can be described by the Sestak-Berggren model. The main decomposition step (the first dominant process) involves the overcoming of weak interactions between CTMAB and the silica network and proceeds with a lower Ea value (116±2 kJ mol-1) than the second dominant process (153±5 kJ mol-1), which can be explained by the size reduction of the pore openings due to the contraction of the SBA-3 unit cell caused by the removal of CTMAB.

A novel layered zincophosphate (ZnPO–MPA) was prepared by hydrothermal crystallization using 3-methylaminopropylamine (MPA) as a structure-directing agent. The structure consists of macroanion [Zn2P3O8(OH)3]2- layers which are built up of 4-membered ring channels. The channels (of about 3.7 Å diameter) arise through the connection of the neighbouring rings by two oxygen bridges. The negative charge of the layers is compensated by diprotonated MPA molecules which are stacked parallel to the ring channels. ZnPO–MPA is stable up to 300 °C. At higher temperatures MPA decomposition begins followed by a dehydration, which occurs through condensation of the framework hydroxyl groups. The activation energy of the MPA decomposition is high due to the fact that the layers and MPA cations are held together by strong hydrogen bonds.

This review is a brief summary of open-framework aluminophosphates and their transition metal-substituted modifications. The materials exhibit structural and compositional diversity, as well as a wide range of pore openings, which are crystallographically ordered and can be tuned by an appropriate choice of synthesis conditions. The diameters of the apertures, cages and channels fall in the range of 0.4 to about 1.5 nm, which recommends aluminophosphates for a novel area of application-nanocatalysis. Isomorphous substitution of the framework elements by transition metal ions which possess redox ability creates active sites inside the aluminophosphate lattice and opens routes towards shape selective bi-functional catalysis. In order to obtain an insight into the location of the transition metal ions, different characterization techniques have to be used.

1,3-Diaminopropane (DAP) was used as a structure-directing agent for the hydrothermal synthesis of an organically templated iron phosphate. During crystallization at 180 ºC, iron phosphate (FePO-DAP) with a layered structure was formed after one day. Longer crystallization yielded a mixture of FePO-DAP and leucophosphite, raising the question whether a transformation of FePO-DAP to leucophosphite occurs, or whether DAP decomposes under hydrothermal conditions resulting in leucophosphite formation. Lattice energy and free energy calculations strongly support the supposition that a decomposition of DAP occurs prior to the formation of leucophosphite.

Research background. In the recent years, considerable attention has been given to selenium status since its deficiency is linked with various disorders and affects at least 13 % of world population. Additionally, mushrooms are known to possess pronounced capacity for absorption of various micronutrients, including Se, from soil/substrate. Here, we investigate the possibility of using Se-rich zeolitic tuff as a supplement for production of selenized mushroom. Furthermore, the impact of the enrichment on the activity of antioxidant enzymes and biological potential of Coriolus versicolor medicinal mushroom is studied. Experimental approach. Se(IV)- and Se(VI)-modified natural zeolitic tuff from the Serbian deposit Zlatokop was used as supplement for mushroom cultivation. To examine the effectiveness of selenium enrichment, we determined total selenium with inductively coupled plasma mass spectrometry (ICP-MS), together with the activity of antioxidant enzymes in fresh fruiting bodies and biological potential of methanolic extracts. Antioxidant activity was evaluated using the appropriate tests for: inhibition of lipid peroxidation, DPPH free radical scavenging assay, Fe(III)-reducing antioxidant power assay and ability of chelating Fe2+ ions. The antibacterial activity against foodborne pathogens was measured by broth microdilution assay. Additionally, chemical composition of the prepared extracts was studied using UV-Vis and Fourier transform infrared (FTIR) spectroscopy. Results and conclusions. Content of selenium detected in biofortified C. versicolor was even 470 times higher than in control on dry mass basis ((140.7±3.8) vs (0.3±0.1) µg/g), proving that Se-rich zeolitic tuff is an excellent supplement for mushroom production. Furthermore, the results of monitoring the activity of antioxidant enzymes revealed that most of the Se-enriched mushrooms exhibited higher superoxide dismutase (SOD) and catalase (CAT) and lower glutathione peroxidase (GSH-Px) activities than control. Due to higher amounts of enzymes, which can quickly catalyze the reduction of superoxide radicals, the quality of selenium-enriched mushrooms is preserved for a longer period of time. Investigation of biological potential indicated that Se-enriched mushroom methanolic extracts, generally, expressed enhanced antioxidant properties. Additionally, extracts showed antibacterial activity against all tested pathogenic microorganisms. Novelty and scientific contribution. Cultivation of mushrooms on Se-enriched zeolitic tuff is a new technological approach for obtaining Se-fortified food/supplements with enhanced antioxidant and antibacterial activities. [ABSTRACT FROM AUTHOR]

Due to the development of resistance to antimicrobial agents, bacterium Acinetobacter baumannii is nowadays a leading cause of nosocomial outbreaks. Clinically relevant A. baumannii outside hospital settings including natural soils affected by human waste represents a public-health risk for humans and animals. The aim of this study was to investigate the potential of metal-loaded zeolites to eliminate viable A. baumannii from artificially contaminated natural soils. A. baumannii isolate was subjected to the activity of natural zeolitised tuff (NZ) and Cu-modified (CuNZ) or Ag-modified zeolite (AgNZ) in wet, slightly acidic terra rossa and slightly alkaline red palaeosol. A. baumannii survived in terra rossa and red palaeosol supplemented with 1 wt% of NZ for seven days and four months, respectively. The addition of 1 wt% of CuNZ to terra rossa and red palaeosol shortened the survival of A. baumannii to three and 14 days, respectively. The addition of 0.1 wt% of AgNZ to both soils resulted in complete removal of viable A. baumannii within 1 h of contact, while the total native heterotrophic bacterial counts remained high. Since AgNZ is prepared with a simple modification of cost-effective and environmentally friendly natural zeolite, it is a promising material for the remediation of soils contaminated with pandrug-resistant A. baumannii. [ABSTRACT FROM AUTHOR]

Antibacterial activity of a natural zeolite, clinoptilolite (Z), enriched with about 0.4-0.5 mmol of Ag (Ag-Z), Cu (Cu-Z) or Zn (Zn-Z) was tested toward two strains of Gram-negative bacteria - Escherichia coli and Acinetobacter baumannii - in natural seawater from Adriatic Sea (Croatia). The Ag-Z and Cu-Z exhibited bactericidal activity toward E. coli and A. baumannii after 3 and 6 h of exposure, respectively. The Zn-Z showed antibacterial activity toward both strains, but lacking the bactericidal effect even after 24 h of exposure. All studied samples released metal cations in seawater. Concentration of Ag and Zn leached from Ag-Z and Zn-Z was higher than maximum allowable concentrations (MAC) for drinking water, whereas concentration of Cu was below MAC. Due to high concentration of Na+ in seawater (about 1.2 g Na+ dm-3) an ion-exchange process can be responsible for the leaching of the studied cations. The lowest extent of leaching from Cu-Z was ascribed to different position and geometry of sites occupied by Cu(II) in the clinoptilolite lattice. The antibacterial activity of M-Z was attributed to the metal cations leached from the zeolite lattice into seawater. The obtained results indicate that Cu-Z can be considered as a promising disinfectant for treatment of seawater. [ABSTRACT FROM AUTHOR]