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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.

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.

The use of antibiotics constantly increases which has a notable negative impact on water bodies. Ciprofloxacin (CIP) is widely applied antibiotic in both human and veterinary medicine, as well as in a livestock breeding. Due to its extensive use, CIP has been found in wastewater effluents in a wide concentration range from ng to mg dm^(–3). An extremely high concentration of up to 50 mg dm^(–3) has been found near drug manufacturing plants [1]. Since CIP, as well as many other pharmaceuticals, cannot be efficiently removed from wastewater streams by conventional wastewater treatments, it is of a great importance to find an acceptable method for their removal. This study reports the use of natural calcium-rich clinoptilolite (CLI) for the adsorption of CIP and regeneration of the spent adsorbent (CLI-CIP) by non-thermal atmospheric pressure plasma (NTP). The results show that the CLI possesses a high adsorption efficiency in removal of CIP at 283, 288 and 293 K in a slightly acidic medium (pH= 5) for the initial concentrations from 15 to 75 mg dm^(–3). The CIP adsorption by CLI follows the Lagergren’s pseudo-second-order kinetics and it can be described well by the Langmuir isotherm model. For all studied temperatures and initial concentrations more than 85% of the CIP is removed within the first 10 minutes. The results also indicate that the CIP adsorption mechanism includes two phenomena: 1) electrostatic interactions between negatively charged aluminosilicate lattice and cationic form of CIP species and 2) ion-exchange reaction. The use of NTP for the regeneration of CLI-CIP was based on the assumption that NTP generates highly reactive species which can induce a cleavage of the bonds formed between active sites on the CLI surface and CIP, and also induce the CIP decomposition. The NTP treatment was performed for a short time, with a low energy consumption, and without using the additional chemicals. All these make the procedure acceptable not only from economical

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.

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 anti-oxidant enzymes and biological potential of Coriolus versicolor medicinal mushroom is studied. Experimental approach. Se(IV)-and Se(VI)-modified natural zeolitic tuff from the Ser-bian 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

Natural clinoptilolite (CLI) exhibited a high efficacy in ciprofloxacin (CIP) removal from aqueous solution by adsorption. However, the regeneration of the spent adsorbent was a challenge since the adsorption occurred via electrostatic interactions and ion-exchange reaction. Herein, the feasibility of non-thermal plasma (NTP) was studied for the regeneration of ciprofloxacin-containing clinoptilolite (CIP-CLI) in five successive adsorption/NTP regeneration cycles. The NTP treatments were performed using a surface dielectric barrier discharge (SDBD) operating at atmospheric pressure in air. Plasma discharge gap, sample mass, and electrode surfaces were varied to find optimal regeneration parameters. For the plasma source with an electrode surface of 37.2 cm2, the 2 mm electrode gap and 20 min of plasma treatment were found as optimal parameters (sample mass of 0.2 g). The plasma treatment did not affect clinoptilolite features which were concluded from a study of textural properties and powder X-ray diffraction (PXRD) analysis. X-ray photoelectron spectroscopy (XPS) showed a decrease of total carbon content with around 10% of carbon residual left on the surface. The CLI adsorption capacity can be regenerated to at least 90% of its initial capacity during the five successive cycles, showing the involvement of plasma reactive species in decomposition of adsorbed CIP.

The present study focuses on clinoptilolite (CLI)-rich natural zeolitic tuffs and their photocatalytic activity in the degradation of cationic organic dyes. CLI from different regions was tested in the photocatalytic degradation of methylene blue (MB) as a model cationic dye. The photocatalytic tests were performed at room temperature and atmospheric pressure under visible light irradiation. For all the CLI samples, the highest activity was observed at pH = 6. Total MB degradation varied between 70 and 91% (C0 = 10 mg dm–3, 0.2 g dm–3 of photocatalyst, during 300 min). It is suggested that the presence of Fe species in the studied tuffs is responsible for the photocatalytic activity. The activity increases linearly with the Fe content in the tuffs. The MB photodegradation follows the Langmuir–Hinshelwood kinetic model. The recyclability tests showed good stability and efficiency of the photocatalyst. The degradation rate decreased from 91 to 69% during three reaction cycles, indicating a promising potential of natural zeolites in the treatment of textile industry wastewater.

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) mu g/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 cata lase (CAT) and lower glutathione peroxidase (GSH-Px) a

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 anti-oxidant enzymes and biological potential of Coriolus versicolor medicinal mushroom is studied. Experimental approach. Se(IV)-and Se(VI)-modified natural zeolitic tuff from the Ser-bian 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

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 anti-oxidant enzymes and biological potential of Coriolus versicolor medicinal mushroom is studied. Experimental approach. Se(IV)-and Se(VI)-modified natural zeolitic tuff from the Ser-bian 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

Natural clinoptilolite (CLI) exhibited a high efficacy in ciprofloxacin (CIP) removal from aqueous solution by adsorption. However, the regeneration of the spent adsorbent was a challenge since the adsorption occurred via electrostatic interactions and ion-exchange reaction. Herein, the feasibility of non-thermal plasma (NTP) was studied for the regeneration of ciprofloxacin-containing clinoptilolite (CIP-CLI) in five successive adsorption/NTP regeneration cycles. The NTP treatments were performed using a surface dielectric barrier discharge (SDBD) operating at atmospheric pressure in air. Plasma discharge gap, sample mass, and electrode surfaces were varied to find optimal regeneration parameters. For the plasma source with an electrode surface of 37.2 cm2, the 2 mm electrode gap and 20 min of plasma treatment were found as optimal parameters (sample mass of 0.2 g). The plasma treatment did not affect clinoptilolite features which were concluded from a study of textural properties and powder X-ray diffraction (PXRD) analysis. X-ray photoelectron spectroscopy (XPS) showed a decrease of total carbon content with around 10% of carbon residual left on the surface. The CLI adsorption capacity can be regenerated to at least 90% of its initial capacity during the five successive cycles, showing the involvement of plasma reactive species in decomposition of adsorbed CIP.

The present study focuses on clinoptilolite (CLI)-rich natural zeolitic tuffs and their photocatalytic activity in the degradation of cationic organic dyes. CLI from different regions was tested in the photocatalytic degradation of methylene blue (MB) as a model cationic dye. The photocatalytic tests were performed at room temperature and atmospheric pressure under visible light irradiation. For all the CLI samples, the highest activity was observed at pH = 6. Total MB degradation varied between 70 and 91% (C0 = 10 mg dm–3, 0.2 g dm–3 of photocatalyst, during 300 min). It is suggested that the presence of Fe species in the studied tuffs is responsible for the photocatalytic activity. The activity increases linearly with the Fe content in the tuffs. The MB photodegradation follows the Langmuir–Hinshelwood kinetic model. The recyclability tests showed good stability and efficiency of the photocatalyst. The degradation rate decreased from 91 to 69% during three reaction cycles, indicating a promising potential of natural zeolites in the treatment of textile industry wastewater.

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 th, Pozadina istraživanja. Posljednjih se godina sve veća pažnja posvećuje udjelu selena u organizmu, s obzirom na to da se nedostatak ovog elementa u prehrani povezuje s pojavom mnogih bolesti koje pogađaju najmanje 13 % svjetske populacije. Prethodna su istraživanja pokazala da gljive uspješno apsorbiraju različita mikrohranjiva iz tla odnosno supstrata, uključujući i selen. Svrha je ovog rada bila ispitati mogućnost primjene zeolitnog tufa bogatog selenom kao dodatka u proizvodnji gljiva obogaćenih selenom. Uz to, ispitan je utjecaj obogaćivanja na aktivnost antioksidacijskih enzima i biološki potencijal medicinske gljive Coriolus versicolor. Eksperimentalni pristup. Prirodni zeolit bogat Se(IV) i Se(VI) iz rudnika Zlatokop (Srbija) upotrijebljen je kao izvor selena u proizvodnji gljiva na čvrstom supstratu. Za utvrđivanje uspješnosti obogaćivanja gljive selenom ispitani su sljedeći parametri: ukupni udjel selena, i to masenom spektrometrijom s induktivno spregnutom plazmom (ICP-MS), aktivnost antioksidacijskih enzima u svježim plodištima gljiva, te biološki potencijal metanolnih ekstrakata. Antioksidacijska aktivnost ispitana je sljedećim metodama: inhibicijom lipidne peroksidacije, mjerenjem sposobnosti hvatanja slobodnih DPPH radikala, metodom FRAP i određivanjem sposobnosti keliranja iona željeza. Antibakterijski učinak ekstrakata na patogene iz hrane ispitan je mikrodilucijskom metodom. Nadalje, kemijski je sastav ekstrakata ispitan pomoću UV-Vis i Fourier transformirane infracrvene spektroskopije (FTIR). Rezultati i zaključci. Udjel selena u gljivi Coriolus versicolor obogaćenoj selenom bio je i do 470 puta veći nego u kontrolnom uzorku ((140.7±3.8) naspram (0.3±0.1) µg po g suhe tvari), što potvrđuje da se zeolitni tuf bogat selenom može uspješno primjeniti za obogaćivanje gljiva selenom. Praćenjem aktivnosti antioksidacijskih enzima utvrđeno je da većina uzoraka gljiva obogaćenih selenom ima veću aktivnost superoksid dismutaze (SOD) i katalaze (CAT) te manju

Novel composites based on natural zeolite-clinoptilolite and monoterpene phenols-thymol and carvacrol were prepared by supercritical solvent impregnation (SSI) in supercritical carbon dioxide (scCO(2)) at 30 MPa and 35 degrees C during 18 h. The content of phenols in composites (thymol-23.0 and carvacrol-19.1 wt%) was determined using both C,H,N and thermal analysis (TGA); interactions of the phenols with the zeolite lattice studied by Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffraction (PXRD) showed that the zeolite lattice was preserved in the composites. The composites exhibited antibacterial activity toward Gram-negative bacteria Escherichia coli DSM 498 and Gram-positive bacteria Staphylococcus aureus ATCC 25923 in different water media (phosphate buffer solution, spring water and lake water). After 1 h carvacrol-containing clinoptilolite showed better antibacterial activity than composite with thymol. Both composites expressed bactericidal effect after 24 h of contact. Leaching of the phenols from composite in water was more pronounced from thymol (22.7-32.1%) than for carvacrol (6.2-8.9%) suggesting influence of steric effect on the desorption process.

The adsorption of the antibiotic ciprofloxacin (CIP) from an aqueous solution by natural zeolite, the calcium-rich clinoptilolite (CLI), and magnetite-coated CLI (MAG-CLI) was investigated. Both CLI and MAG-CLI showed a high adsorption affinity towards CIP at 283, 288 and 293 K at a pH of 5. Adsorption kinetics studied for the initial concentrations of 15-75 mg CIP dm(-3) follow Lagergren's pseudo-second order equation and the adsorption is best represented by the Langmuir model. The adsorption mechanism involves strong electrostatic interactions between negatively charged aluminosilicate lattice and the cationic form of CIP accompanied by an ion-exchange reaction. Magnetite coverage (approx. 12 wt.%) induces magnetism, which can facilitate the separation process. The coverage does not influence the adsorption activity of CLI. The leaching test showed that the MAG coating protects the adsorbent from CIP leaching. This is ascribed to interactions between the CIP carboxyl groups and magnetite nano-particles. Antibacterial tests showed strong antibacterial activity of the ciprofloxacin-containing adsorbents towards pathogenic E. coli and S. aureus.

Due to their structural complexity, chemical stability, and toxicity, organic dyes mostly used in the textile industry, cause serious environmental problems. Advanced Oxidation Processes (AOPs) currently appear to offer a high potential for complete degradation of organic dyes. The present work is focused on natural clinoptilolite (CLI) and its unusual photocatalytic activity. CLI from different regions were studied as photocatalysts in the photodegradation of methylene blue (MB) as a model cationic dye under visible light at room temperature and atmospheric pressure at different pH. For all CLI samples at pH = 6, the total degradation degree of MB varied from 74 to 88 %, thus indicating a high photocatalytic activity of CLI.

Due to their structural complexity, chemical stability, and toxicity, organic dyes mostly used in the textile industry, cause serious environmental problems. Advanced Oxidation Processes (AOPs) currently appear to offer a high potential for complete degradation of organic dyes. The present work is focused on natural clinoptilolite (CLI) and its unusual photocatalytic activity. CLI from different regions were studied as photocatalysts in the photodegradation of methylene blue (MB) as a model cationic dye under visible light at room temperature and atmospheric pressure at different pH. For all CLI samples at pH = 6, the total degradation degree of MB varied from 74 to 88 %, thus indicating a high photocatalytic activity of CLI.

The adsorption of the antibiotic ciprofloxacin (CIP) from an aqueous solution by natural zeolite, the calcium-rich clinoptilolite (CLI), and magnetite-coated CLI (MAG-CLI) was investigated. Both CLI and MAG-CLI showed a high adsorption affinity towards CIP at 283, 288 and 293 K at a pH of 5. Adsorption kinetics studied for the initial concentrations of 15-75 mg CIP dm(-3) follow Lagergren's pseudo-second order equation and the adsorption is best represented by the Langmuir model. The adsorption mechanism involves strong electrostatic interactions between negatively charged aluminosilicate lattice and the cationic form of CIP accompanied by an ion-exchange reaction. Magnetite coverage (approx. 12 wt.%) induces magnetism, which can facilitate the separation process. The coverage does not influence the adsorption activity of CLI. The leaching test showed that the MAG coating protects the adsorbent from CIP leaching. This is ascribed to interactions between the CIP carboxyl groups and magnetite nano-particles. Antibacterial tests showed strong antibacterial activity of the ciprofloxacin-containing adsorbents towards pathogenic E. coli and S. aureus.

The adsorption of the antibiotic ciprofloxacin (CIP) from an aqueous solution by natural zeolite, the calcium-rich clinoptilolite (CLI), and magnetite-coated CLI (MAG-CLI) was investigated. Both CLI and MAG-CLI showed a high adsorption affinity towards CIP at 283, 288 and 293 K at a pH of 5. Adsorption kinetics studied for the initial concentrations of 15-75 mg CIP dm(-3) follow Lagergren's pseudo-second order equation and the adsorption is best represented by the Langmuir model. The adsorption mechanism involves strong electrostatic interactions between negatively charged aluminosilicate lattice and the cationic form of CIP accompanied by an ion-exchange reaction. Magnetite coverage (approx. 12 wt.%) induces magnetism, which can facilitate the separation process. The coverage does not influence the adsorption activity of CLI. The leaching test showed that the MAG coating protects the adsorbent from CIP leaching. This is ascribed to interactions between the CIP carboxyl groups and magnetite nano-particles. Antibacterial tests showed strong antibacterial activity of the ciprofloxacin-containing adsorbents towards pathogenic E. coli and S. aureus.

Novel composites based on natural zeolite-clinoptilolite and monoterpene phenols-thymol and carvacrol were prepared by supercritical solvent impregnation (SSI) in supercritical carbon dioxide (scCO(2)) at 30 MPa and 35 degrees C during 18 h. The content of phenols in composites (thymol-23.0 and carvacrol-19.1 wt%) was determined using both C,H,N and thermal analysis (TGA); interactions of the phenols with the zeolite lattice studied by Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffraction (PXRD) showed that the zeolite lattice was preserved in the composites. The composites exhibited antibacterial activity toward Gram-negative bacteria Escherichia coli DSM 498 and Gram-positive bacteria Staphylococcus aureus ATCC 25923 in different water media (phosphate buffer solution, spring water and lake water). After 1 h carvacrol-containing clinoptilolite showed better antibacterial activity than composite with thymol. Both composites expressed bactericidal effect after 24 h of contact. Leaching of the phenols from composite in water was more pronounced from thymol (22.7-32.1%) than for carvacrol (6.2-8.9%) suggesting influence of steric effect on the desorption process.

The thesis has two interconnected general goals. The first one was to develop novel, environmentally friendly and cost-efficient soil supplements using natural zeolite (clinoptilolite, CLI) which will retain plant nutrients (nitrogen, potassium and phosphorus) in different soil types and accordingly increase biomass production. The second one was to develop effective clinoptilolite-based catalysts for biomass conversion into industrial valuable chemicals. To achieve the first aim, nitrate and phosphate adsorption onto CLI modified with several oxides were studied. The obtained results showed that the oxide coverage of CLI surface makes it accessible for effective binding of nitrate and phosphate ions. The best adsorption ability was obtained for Fe(III)-enriched CLI (FeCLI). FeCLI shows significantly better retention effect than CLI but the leaching depends on soil types. Nitrate retention increases by the zeolite addition only for silty loam and silty clay soils whereas potassium retention increases in the following order: silty loam < silty clay << sandy soil. FeCLI shows a retention effect in phosphate leaching only from sandy soil. The second goal was development of a CLI-based catalyst effective in the esterification of levulinic acid (LA) which can be obtained from biomass. The catalysts were prepared from CLI and SnO2 or sulfated SnO2. Sulfated catalysts are more active than nonsulfated ones. Nonsulfated catalysts showed a high activity in the conversion of LA into octyl levulinate (55%) and moderate activity in the conversion into ethyl levulinate (22%), whereas sulfated catalysts led to a total conversion of LA to esters., Teza ima dva međusobno povezana opšta cilja. Prvi cilj je dobijanje novog, ekološki prihvatljivog i jeftinog zemljišnog suplementa korišćenjem prirodnog zeolita (klinoptilolit, CLI) koji će zadržati biljne nutrijente (azot, kalijum i fosfor) u različitim vrstama zemljišta i shodno tome povećati proizvodnju biomase. Drugi cilj je dobijanje efikasnog katalizatora na bazi klinoptilolita za konverziju biomase u industrijski važne hemikalije. Za postizanje prvog cilja, proučavana je adsorpcija nitrata i fosfata na CLI koji je bio modifikovan sa nekoliko oksida. Dobijeni rezultati pokazali su da oksidna prevlaka na površini CLI omogućava efikasno vezanje nitrata i fosfata. Najbolja adsorpciona sposobnost dobijena je za Fe(III)-obogaćen CLI (FeCLI). FeCLI pokazuje značajno bolji efekat zadržavanja ispitivanih jona u odnosu na CLI, ali izluživanje zavisi od vrste zemljišta. Zadržavanje nitrata povećava se dodatkom zeolita u praškastu glinu i praškastu ilovaču, dok se zadržavanje kalijuma povećava sledećim redosledom: praškasta ilovača < praškasta glina << peskuša. FeCLI pokazuje efekat zadržavanja fosfata samo za peskuše. Drugi cilj teze bio je razvoj efikasnog katalizatora zasnovanog na CLI, za primenu u esterifikaciji levulinske kiseline (LA) koja se može dobiti iz biomase. Katalizator je pripremljen iz CLI i SnO2 ili sulfatiranog SnO2. Sulfatirani katalizatori pokazali su veću aktivnost u odnosu na nesulfatirane. Nesulfatirani katalizatori pokazali su aktivnost u konverziji LA u oktil levulinat (55%) i umerenu aktivnost u konverziji u etil levulinat (22%), dok su sulfatirani katalizatori LA u potpunosti konvertovali u estre.

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.

Due to their adsorbent, ion exchange and catalytic properties zeolites are suitable for a variety of applications. We report on the photocatalytic activity of a readily available and inexpensive natural zeolite clinoptilolite (Z) containing SnO2 (Sn-Z). The Sn-Z samples with 3-15 wt. % of Sn were prepared by using a precipitation-deposition method. Powder X-ray diffraction analysis showed that the zeolite structure was unaffected by the introduction of the Sn-phase. Diffuse reflectance UV/VIS spectra of the Sn-Z samples confirmed the presence of SnO2 and X-Ray absorption spectroscopy analyses suggested that the SnO2 particles mainly resided on the surface of the clinoptilolite, while ATR-FTIR analysis gave some clues that part of the SnO2 phase was incorporated in the pores of the zeolite. The presence of SnO2 in Sn-Z increased both adsorption capacity and photocatalytic performance which could be partially explained by higher surface area and partially with an increased negative potential of the surface. Adsorption and total degradation of methylene blue (MB) for the Sn-Z with the highest amount of Sn (15 wt.%) was about 30% and 45%, respectively, suggesting a synergetic effect between SnO2 and the clinoptilolite lattice. Reusability tests showed that these catalysts present a promising material for water purification.

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.

Natural zeolite – clinoptilolite (CLI) from Serbian deposit Slanci (near the capital city Belgrade) was investigated as adsorbent for the adsorption of antibiotic ciprofloxacin (CIP) as a model organic micropollutant (OMP) present in wastewater. At 20 °C the adsorption capacity varies from 4.81 to 8.90 mg g-1 for the initial CIP solution concentration of 15 and 50 mg CIP dm–3, respectively. The adsorption isotherms at 10, 15 and 20 °C are best represented by the Langmuir model and the adsorption kinetics by the Lagergren's pseudosecond-order equation. The adsorption mechanism most probably involves an ion-exchange reaction occurred at the CLI surface and according to results of Weber-Morris model does not involve intra-particle diffusion.

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.

Due to their adsorbent, ion exchange and catalytic properties zeolites are suitable for a variety of applications. We report on the photocatalytic activity of a readily available and inexpensive natural zeolite clinoptilolite (Z) containing SnO2 (Sn-Z). The Sn-Z samples with 3-15 wt. % of Sn were prepared by using a precipitation-deposition method. Powder X-ray diffraction analysis showed that the zeolite structure was unaffected by the introduction of the Sn-phase. Diffuse reflectance UV/VIS spectra of the Sn-Z samples confirmed the presence of SnO2 and X-Ray absorption spectroscopy analyses suggested that the SnO2 particles mainly resided on the surface of the clinoptilolite, while ATR-FTIR analysis gave some clues that part of the SnO2 phase was incorporated in the pores of the zeolite. The presence of SnO2 in Sn-Z increased both adsorption capacity and photocatalytic performance which could be partially explained by higher surface area and partially with an increased negative potential of the surface. Adsorption and total degradation of methylene blue (MB) for the Sn-Z with the highest amount of Sn (15 wt.%) was about 30% and 45%, respectively, suggesting a synergetic effect between SnO2 and the clinoptilolite lattice. Reusability tests showed that these catalysts present a promising material for water purification.

Due to their adsorbent, ion exchange and catalytic properties zeolites are suitable for a variety of applications. We report on the photocatalytic activity of a readily available and inexpensive natural zeolite clinoptilolite (Z) containing SnO2 (Sn-Z). The Sn-Z samples with 3-15 wt. % of Sn were prepared by using a precipitation-deposition method. Powder X-ray diffraction analysis showed that the zeolite structure was unaffected by the introduction of the Sn-phase. Diffuse reflectance UV/VIS spectra of the Sn-Z samples confirmed the presence of SnO2 and X-Ray absorption spectroscopy analyses suggested that the SnO2 particles mainly resided on the surface of the clinoptilolite, while ATR-FTIR analysis gave some clues that part of the SnO2 phase was incorporated in the pores of the zeolite. The presence of SnO2 in Sn-Z increased both adsorption capacity and photocatalytic performance which could be partially explained by higher surface area and partially with an increased negative potential of the surface. Adsorption and total degradation of methylene blue (MB) for the Sn-Z with the highest amount of Sn (15 wt.%) was about 30% and 45%, respectively, suggesting a synergetic effect between SnO2 and the clinoptilolite lattice. Reusability tests showed that these catalysts present a promising material for water purification.

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.

Catalysts based on natural zeolite - clinoptilolite loaded with either SnO2 (TOHCLI) or sulfated SnO2 (STOHCLI) were prepared and tested in the esterification of levulinic acid (LA) with octanol or ethanol. The Sn content in TOHCLI and STOHCLI varied from 4.5 to 12.3 wt.%. The catalysts were characterized by powder X-ray diffraction method, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, thermal analysis, X-ray photoelectron spectroscopy, NZ physisorption at - 196 degrees C, (27)A1 and Si-29 MAS NMR solid state spectroscopy and FTIR spectroscopy for analysis of acidic centers. A high conversion rate of LA into octyl- (OLA) or ethyl levulinate (ELA) was obtained for both TOHCLI and STOHCLI. TOHCLI showed a high activity in the conversion of LA into OLA (55%) and a moderate activity in the conversion to ELA (22%). STOHCLI led to a total conversion of LA to OLA and ELA due to the presence of a high amount of Bronsted and Lewis acid sites in the catalysts. The catalytic activity decreased to 86% for OLA and to 66% for ELA after next five cycles. Lower catalytic activity in the repeated cycles during ELA formation was explained by pore blockage due to coke formation.

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.

Due to structural complexity and toxicity of organic dyes their presence in water body causes usually serious environmental problems. Advanced Oxidation Processes (AOPs) have been recognized as effective methods for a complete degradation of organic dyes. In this study, Serbian natural zeolite (clinoptilolite) loaded with Fe(III) was used for the preparation of a photocatalyst and its catalytic activity was tested in the photodegradation of methylene blue (MB) as a model cationic dye under visible light at room temperature and atmospheric pressure. It is showed that the prepared Fe(III)-containing clinoptilolite (FeZ) can be used as active and recyclable photocatalyst in degradation of MB.

Due to structural complexity and toxicity of organic dyes their presence in water body causes usually serious environmental problems. Advanced Oxidation Processes (AOPs) have been recognized as effective methods for a complete degradation of organic dyes. In this study, Serbian natural zeolite (clinoptilolite) loaded with Fe(III) was used for the preparation of a photocatalyst and its catalytic activity was tested in the photodegradation of methylene blue (MB) as a model cationic dye under visible light at room temperature and atmospheric pressure. It is showed that the prepared Fe(III)-containing clinoptilolite (FeZ) can be used as active and recyclable photocatalyst in degradation of MB.

Composites based on natural zeolite – clinoptilolite and thymol were prepared using two different approaches: 1) wet impregnation (WI) and supercritical solvent impregnation (SSI). The SSI was more superior since it yielded the composite with higher amount of thymol and with stronger thymol-clinoptilolite interactions than WI. The composites exhibited antibacterial activity towards Gram-negative bacteria Escherichia coli and Grampositive bacteria Staphylococcus aureus suggesting its applicability for disinfectant purposes.

Ovo je treće, dopunjeno i delimično izmenjeno izdanje Praktikuma iz neorganske hemije. Praktikum je namenjen prvenstveno studentima Tehnološko-metalurškog fakulteta u Beogradu, koji su upisali predmet Neorganska hemija i stekli neophodna teorijska i praktična znanja iz predmeta Opšta hemija, Analitička hemija i Organska hemija. Praktikum sačinjavaju dve celine: EKSPERIMENTALNI ZADACI – sadrži uputstva za izradu samostalnih eksperimentalnih zadataka. Svako uputstvo pripremljeno je tako da sadrži kratak teorijski uvod koji bi trebalo da doprinese lakšem razumevanju suštine samog eksperimentalnog postupka, opis postupka, kao i zadatke i pitanja na koje je student dužan da odgovori u pisanom izveštaju. PRILOG - sadrži osnove najvažnijih metoda karakterizacije neorganskih supstanci. U ovom delu se nalazi i primer jednog sređenog izveštaja o urađenom zadatku koji treba da posluži kao pomoć pri sastavljanju individualnih izveštaja.

Composites based on natural zeolite – clinoptilolite and thymol were prepared using two different approaches: 1) wet impregnation (WI) and supercritical solvent impregnation (SSI). The SSI was more superior since it yielded the composite with higher amount of thymol and with stronger thymol-clinoptilolite interactions than WI. The composites exhibited antibacterial activity towards Gram-negative bacteria Escherichia coli and Grampositive bacteria Staphylococcus aureus suggesting its applicability for disinfectant purposes.

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.

Catalysts based on natural zeolite - clinoptilolite loaded with either SnO2 (TOHCLI) or sulfated SnO2 (STOHCLI) were prepared and tested in the esterification of levulinic acid (LA) with octanol or ethanol. The Sn content in TOHCLI and STOHCLI varied from 4.5 to 12.3 wt.%. The catalysts were characterized by powder X-ray diffraction method, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, thermal analysis, X-ray photoelectron spectroscopy, NZ physisorption at - 196 degrees C, (27)A1 and Si-29 MAS NMR solid state spectroscopy and FTIR spectroscopy for analysis of acidic centers. A high conversion rate of LA into octyl- (OLA) or ethyl levulinate (ELA) was obtained for both TOHCLI and STOHCLI. TOHCLI showed a high activity in the conversion of LA into OLA (55%) and a moderate activity in the conversion to ELA (22%). STOHCLI led to a total conversion of LA to OLA and ELA due to the presence of a high amount of Bronsted and Lewis acid sites in the catalysts. The catalytic activity decreased to 86% for OLA and to 66% for ELA after next five cycles. Lower catalytic activity in the repeated cycles during ELA formation was explained by pore blockage due to coke formation.

Catalysts based on natural zeolite – clinoptilolite loaded with either SnO2 (TOHCLI) or sulfated SnO2 (STOHCLI) were prepared and tested in the esterification of levulinic acid (LA) with octanol or ethanol. The Sn content in TOHCLI and STOHCLI varied from 4.5 to 12.3 wt.%. The catalysts were characterized by powder X-ray diffraction method, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, thermal analysis, X-ray photoelectron spectroscopy, N2 physisorption at −196 °C, 27Al and 29Si MAS NMR solid state spectroscopy and FTIR spectroscopy for analysis of acidic centers. A high conversion rate of LA into octyl- (OLA) or ethyl levulinate (ELA) was obtained for both TOHCLI and STOHCLI. TOHCLI showed a high activity in the conversion of LA into OLA (55%) and a moderate activity in the conversion to ELA (22%). STOHCLI led to a total conversion of LA to OLA and ELA due to the presence of a high amount of Brønsted and Lewis acid sites in the catalysts. The catalytic activity decreased to 86% for OLA and to 66% for ELA after next five cycles. Lower catalytic activity in the repeated cycles during ELA formation was explained by pore blockage due to coke formation.

Catalysts based on natural zeolite - clinoptilolite loaded with either SnO2 (TOHCLI) or sulfated SnO2 (STOHCLI) were prepared and tested in the esterification of levulinic acid (LA) with octanol or ethanol. The Sn content in TOHCLI and STOHCLI varied from 4.5 to 12.3 wt.%. The catalysts were characterized by powder X-ray diffraction method, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, thermal analysis, X-ray photoelectron spectroscopy, NZ physisorption at - 196 degrees C, (27)A1 and Si-29 MAS NMR solid state spectroscopy and FTIR spectroscopy for analysis of acidic centers. A high conversion rate of LA into octyl- (OLA) or ethyl levulinate (ELA) was obtained for both TOHCLI and STOHCLI. TOHCLI showed a high activity in the conversion of LA into OLA (55%) and a moderate activity in the conversion to ELA (22%). STOHCLI led to a total conversion of LA to OLA and ELA due to the presence of a high amount of Bronsted and Lewis acid sites in the catalysts. The catalytic activity decreased to 86% for OLA and to 66% for ELA after next five cycles. Lower catalytic activity in the repeated cycles during ELA formation was explained by pore blockage due to coke formation.

Cilj ove teze bio je da se ispita dobijanje novih dezinficijenasa na bazi dve vrste zeolita: prirodnog klinoptilolita i zeolita A koji predstavljaju prihvatljive sirovine sa ekološkog i ekonomskog stanovišta. Ovi zeoliti su obogaćeni katjonima Ni, Cu, Zn i Ag u različitim koncentracijama i antibakterijska aktivnost dobijenih proizvoda ispitana je u odnosu na Gram-negativne (Escherichia coli i Acinetobacter baumannii) i Grampozitivne vrste bakterije (Staphylococcus aureus)..., The aim of this thesis was to study preparation of novel disinfectants based on two types of zeolite: natural clinoptilolite and synthetic zeolite A which both present environmental as well as cost efficient materials. These zeolites were enriched with cations of Ni, Cu, Zn and Ag in different concentrations, and their antibacterial activity was investigated toward Gram-negative (Escherichia coli i Acinetobacter baumannii) and Gram-positive bacteria (Staphylococcus aureus)...

Cilj ove teze bio je da se ispita dobijanje novih dezinficijenasa na bazi dve vrste zeolita: prirodnog klinoptilolita i zeolita A koji predstavljaju prihvatljive sirovine sa ekološkog i ekonomskog stanovišta. Ovi zeoliti su obogaćeni katjonima Ni, Cu, Zn i Ag u različitim koncentracijama i antibakterijska aktivnost dobijenih proizvoda ispitana je u odnosu na Gram-negativne (Escherichia coli i Acinetobacter baumannii) i Grampozitivne vrste bakterije (Staphylococcus aureus)..., The aim of this thesis was to study preparation of novel disinfectants based on two types of zeolite: natural clinoptilolite and synthetic zeolite A which both present environmental as well as cost efficient materials. These zeolites were enriched with cations of Ni, Cu, Zn and Ag in different concentrations, and their antibacterial activity was investigated toward Gram-negative (Escherichia coli i Acinetobacter baumannii) and Gram-positive bacteria (Staphylococcus aureus)...

In this study we prepared adsorbents on the basis of clinoptilolite-rich zeolitic tuff (Slanci deposit, Beograd), and chitosan, as well as partially cross-linked chitosan by glutaraldehyde. We investigated removal rate of nickel and zinc ions from the aqueous solution by both adsorbents at 25 °C, adsorption isotherms, adsorption kinetics, regeneration of spent adsorbents and their antibacterial activity. Removal rate of both adsorbents for both studied cations was significantly increased in comparison to unmodified clinoptilolite. The adsorption isotherm for Ni (II) followed the Langmuir model, while isotherm for Zn was in accord with the the Freundlich equation. Adsorption kinetics followed the Lagergren pseudo-second order kinetic model for both adsorbents and cations. The adsorbents can be regenerated to a large extent after use. Unlike unmodified clinoptilolite-based adsorbents, spent adsorbents did not show antibacterial activity. This was ascribed to interactions between chitosan coating and clinoptilolite., U radu su pripremljeni adsorbensi na bazi zeolitskog tufa bogatog klinoptilolitom (ležište Slanci, Beograd) i hitozana, kao i hitozana koji je delimično umrežen glutaraldehidom. Ispitana je efikasnost uklanjanja jona nikla i cinka iz vodenog rastvora pomoću oba adsorbensa na 25 oC, adsorpcione izoterme, kinetika adsorpcije, regeneracija istrošenih adsorbenasa i njihova antibakterijska aktivnost. Efikasnost uklanjanja oba ispitivana katjona značajno se povećava nakon modifikacije. Adsorpciona izoterma Ni(II) sledi Langmirovu, dok Zn(II) Frojndlihovu izotermu. Kinetika adsorpcije odgovara Lagergrenovom modelu pseudodrugog reda. Oba adsorbensa se mogu u velikom stepenu regenerisati nakon upotrebe. Istrošeni adsorbensi, za razliku od nemodifikovanog klinotpilolita, ne pokazuju antibakterijsku aktivnost. Ovo je pripisano interakcijama hitozana sa klinoptilolitom

Clinoptilolite is the most abundant natural zeolite in Serbia, and the Zlatokop deposit (near Vranjska Banja) is the largest deposit. The zeolitic tuff (CT) from Zlatokop contains >70 wt. % clinoptilolite with quartz and feldspar as major mineral impurities. Considering the high clinoptilolite content in the CT, this tuff has been studied in detail as an adsorbent, catalyst carrier and antimicrobial agent. We evaluated the cation-exchange capacity for several toxic metal cations, the sorption efficiency for several anions, the catalytic activity in the processes of valorization of biomass, and the antimicrobial activity of the CT.

In this study we prepared adsorbents on the basis of clinoptilolite-rich zeolitic tuff (Slanci deposit, Beograd), and chitosan, as well as partially cross-linked chitosan by glutaraldehyde. We investigated removal rate of nickel and zinc ions from the aqueous solution by both adsorbents at 25 °C, adsorption isotherms, adsorption kinetics, regeneration of spent adsorbents and their antibacterial activity. Removal rate of both adsorbents for both studied cations was significantly increased in comparison to unmodified clinoptilolite. The adsorption isotherm for Ni (II) followed the Langmuir model, while isotherm for Zn was in accord with the the Freundlich equation. Adsorption kinetics followed the Lagergren pseudo-second order kinetic model for both adsorbents and cations. The adsorbents can be regenerated to a large extent after use. Unlike unmodified clinoptilolite-based adsorbents, spent adsorbents did not show antibacterial activity. This was ascribed to interactions between chitosan coating and clinoptilolite., U radu su pripremljeni adsorbensi na bazi zeolitskog tufa bogatog klinoptilolitom (ležište Slanci, Beograd) i hitozana, kao i hitozana koji je delimično umrežen glutaraldehidom. Ispitana je efikasnost uklanjanja jona nikla i cinka iz vodenog rastvora pomoću oba adsorbensa na 25 oC, adsorpcione izoterme, kinetika adsorpcije, regeneracija istrošenih adsorbenasa i njihova antibakterijska aktivnost. Efikasnost uklanjanja oba ispitivana katjona značajno se povećava nakon modifikacije. Adsorpciona izoterma Ni(II) sledi Langmirovu, dok Zn(II) Frojndlihovu izotermu. Kinetika adsorpcije odgovara Lagergrenovom modelu pseudodrugog reda. Oba adsorbensa se mogu u velikom stepenu regenerisati nakon upotrebe. Istrošeni adsorbensi, za razliku od nemodifikovanog klinotpilolita, ne pokazuju antibakterijsku aktivnost. Ovo je pripisano interakcijama hitozana sa klinoptilolitom

Clinoptilolite is the most abundant natural zeolite in Serbia, and the Zlatokop deposit (near Vranjska Banja) is the largest deposit. The zeolitic tuff (CT) from Zlatokop contains >70 wt. % clinoptilolite with quartz and feldspar as major mineral impurities. Considering the high clinoptilolite content in the CT, this tuff has been studied in detail as an adsorbent, catalyst carrier and antimicrobial agent. We evaluated the cation-exchange capacity for several toxic metal cations, the sorption efficiency for several anions, the catalytic activity in the processes of valorization of biomass, and the antimicrobial activity of the CT.

Two types of zeolites-natural clinoptilolite (NZ) and synthetic zeolite A (A)-were enriched with approx. 0.25 mmol of Cu(II), Zn(II), or Ag(I) ions, and the obtained materials (M-Z) were tested against three different isolates of Escherichia coli. Two isolates were environmental isolates from waters in Serbia whereas the third one was DSM 498. Antibacterial activity was studied in different water media-nutrient-rich media (peptone water), water from Sava Lake, and commercially available spring water. The Ag-containing zeolites showed bactericidal activity in the nutrient-rich peptone water after 1 h of contact. Cu- and Zn-containing zeolites showed bactericidal activity in real water samples. Antibacterial activity of the M-Z decreases in all three examined water media in the following order: Ag-NZ ae Ag-A > Cu-NZ ae Cu-A > Zn-NZ >>> Zn-A, suggesting that mainly the metal type and not the zeolite type have a role in the antibacterial activity. Leaching experiments showed small amounts of the leached Cu(II) and Zn(II) ions, indicating that the antibacterial activity is not due to the metal ions but should be attributed to the M-Z itself. However, leached amounts of Ag(I) from Ag-NZ and Ag-A in peptone water indicate that the released Ag(I) could be mainly responsible for the bactericidal effect of the Ag(I)-containing zeolites. Since no loss of cellular material was found, the antibacterial activity is not attributed to cytoplasmic membrane damage.

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 lt 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.