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Primena biočađi lista drveta Paulovnije kao oplemenjivača zemljišta za uzgoj zdravog travnjaka – PauLChar
No full textBiočađ kao oplemenjivač zemljišta ima istaknute poljoprivredne i ekološke benefite. Zahvaljujući stabilnoj aromatičnoj strukturi biočađ dugoročno poboljšava sadržaj organske materije i ugljenika, povećava poroznost, razmenu jona i kapacitet zadržavanja vode u zemljištu. Iz tog razloga, u ovom tehničkom rešenju ispitujemo potencijal korišćenja lista Paulovnije kao prekursora za proizvodnju materijala za poboljšanje kvaliteta zemljišta. S obzirom da komercijalno gajenje i upotreba stabala Paulovnije stvara ogromnu količinu krupnih listova koji se u većini slučajeva odbacuju kao otpad, na ovaj način se minimizira problem njegovog generisanja. Cilj ovog tehničkog rešenja je da dizajnira tehnološki postupak za dobijanje novog, korisnog materijala – biočađi lista Paulovnije (PauLChar) i da proceni efikasnost njene primene za oplemenjivanje zemljišta koje se koristi za gajenje trave. Dobijena biočađ može biti pogodna za rešavanje problema vezanih za fizičke i hemijske karakteristike tla. Takođe, doprinosi racionalnijem korišćenju hemijskog đubriva, smanjenju kiselosti zemljišta, kao i poboljšanju izgleda i prinosa trave u sušnom periodu. Pregledom dobijenih rezultata ovog tehničkog rešenja može se zaključiti da je PauLChar najefikasniji u kombinaciji sa azotnim đubrivom uz redovno zalivanje travnjaka. Međutim, u uslovima smanjenog zalivanja najbolje su sadnice trave koje sadrže biočađ bez korišćenja đubriva. Sumiranjam rezultata može se zaključiti da proizvod na bazi biočađi – PauLChar ima potencijal da se efikasno koristi za poboljšanje karakteristika zemljišta na kome se nalazi travnjak
Leaching of lead from intermediate products of zinc metallurgy
No full textThe jarosite type of sediment that occurs in the hydrometallurgical production of zinc represents an attractive research area for the valorization of lead. Intermediate products of zinc metallurgy were used for testing: untreated, roasted and water-washed roasted PbAg precipitate. After a detailed insight into the possibility of processing this type of sediment using the hydrometallurgical process, the choice of means for leaching the samples was made, and in the experimental research a solution of magnesium chloride hexahydrate (MgCl2 × 6H2O) was used. The thermodynamic analysis included the calculation of the standard Gibbs energy of chemical leaching reactions and the construction of the Eh/pH diagram of the stability of lead and accompanying metals in the investigated systems. By examining the influence, ratio of sample mass and volume of leaching agent, as well as leaching time, conclusions were reached about the possibilities of leaching Pb from intermediate products of zinc metallurgy. The optimal parameters of the leaching process in the tested systems were determined, i. e. it was shown that in all three tested samples the maximum leaching of lead is achieved at a concentration of MgCl2 × 6H2O of 4 mol/dm3, for a duration of 60 minutes, at a temperature of 80 oC and a solid:liquid ratio of 1:20
Chitosan-clay composite films: investigation of functional and antibacterial properties for potential biomedical application
No full textThe preparation of polymer-clay composites is gaining increasing attention as these functionalized
materials can be used in biomedical fields (Dong et al., 2021). Chitosan is the most abundant natural cationic
polysaccharide polymer, frequently used because of its special properties such as non-toxicity, biocompatibility,
biodegradability, antibacterial activity, and film-forming ability (Jagdale et al., 2024). In this study, chitosanbased
composite films with or without natural clay were prepared, and their functional properties (mass,
thickness, and swelling), as well as their antibacterial activity, were investigated. The natural bentonite from
the Beretnica deposit in the Republic of Serbia (BB) (CEC = 120 meq/100 g), commercial low molecular
weight chitosan (Sigma-Aldrich, USA), glycerol (as plasticizer) and a 1% acetic acid solution were used for
the preparation of composite films by casting and solvent evaporation, at polymer/clay ratios: 1.5:0.0 and
1.5:1.0. The samples were designated as F0 and FBB, respectively. The average mass and thickness of the FBB
composite film (24±2 mg, i.e., 140±6 μm) were increased compared to the parameters of the film prepared
without clay (F0) (12±1 mg, i.e., 75±8 μm). The swelling capacity of the films after 4 h (pH phosphate buffer
5.8 at 37°C) was 536±54% for F0 and 302±43% for FBB. Although the FBB sample showed slightly lower
swelling, the obtained results indicated that the composite film could absorb a considerable amount of water,
which is very important in the case of its application as a wound dressing (Morgado et al., 2015).
The antibacterial activity of the prepared films was tested against Enterococcus faecalis and Escherichia
coli using the log-reduction method. Both F0 and FBB inhibited the growth of E. coli, by 0.64 log10 CFU/
mL for F0 and 1.60 log10 CFU/mL for FBB, compared to the 100% cellulose film used as control, although
the inhibition of F0 was not significant. On the other hand, sample F0 showed pronounced inhibitory activity
(by 1.56 log10 CFU/mL) against E. faecalis, while the sample FBB showed bactericidal activity inhibiting the
chosen Gram+ bacteria growth by 4.0 log10 CFU/mL, compared to the control sample. The results indicate
that the addition of BB significantly increases the antibacterial activity of chitosan films.
Considering the wide distribution of natural bentonite (such as BB in this study), which significantly improves
the properties of chitosan film in terms of antimicrobial potential, these results have a future perspective in the
production of affordable and effective dressings, with still high swelling capacity, for the topical treatment of
damaged and/or infected skin
Chitosan–Clay Mineral Nanocomposites with Antibacterial Activity for Biomedical Application: Advantages and Future Perspectives
No full textPolymers of natural origin, such as representatives of various polysaccharides (e.g., cellulose, dextran, hyaluronic acid, gellan gum, etc.), and their derivatives, have a long tradition in biomedical applications. Among them, the use of chitosan as a safe, biocompatible, and environmentally friendly heteropolysaccharide has been particularly intensively researched over the last two decades. The potential of using chitosan for medical purposes is reflected in its unique cationic nature, viscosity-increasing and gel-forming ability, non-toxicity in living cells, antimicrobial activity, mucoadhesiveness, biodegradability, as well as the possibility of chemical modification. The intuitive use of clay minerals in the treatment of superficial wounds has been known in traditional medicine for thousands of years. To improve efficacy and overcome the ubiquitous bacterial resistance, the beneficial properties of chitosan have been utilized for the preparation of chitosan–clay mineral bionanocomposites. The focus of this review is on composites containing chitosan with montmorillonite and halloysite as representatives of clay minerals. This review highlights the antibacterial efficacy of chitosan–clay mineral bionanocomposites in drug delivery and in the treatment of topical skin infections and wound healing. Finally, an overview of the preparation, characterization, and possible future perspectives related to the use of these advancing composites for biomedical applications is presented
Synergistic recycling of steel tool dust with secondary aluminum
No full textAlthough tool steels have the lowest share in annual crude steel production (estimated 0.1 %)
their sales are manifold higher (estimated no less than 0.3 %). This is only a one indicator that those steels possess very high value, all thanks to its mechanical properties but also their high production costs. Making the tools out of tool steels generates the steel tool dust (STD) that is composed of partially oxidized metals (both iron and alloying elements). Since it doesn’t possess the same chemical composition as the tool steels this dust can’t be recast and valorized, meaning that this waste material needs to be reduced employing other techniques. The aim of this work is to present the aluminothermic procedure of valorization steel tool dust and mill scale (MS) using the aluminium powder produced from packaging materials. In order to calculate the composition of the mixture needed for aluminothermic reaction mass and heat balance is considered. Another aim of this study is to show the potential of using secondary aluminium as a reducing agent in metallothermic reaction applied in
the process of steel tool dust valorization. Resulting iron alloy has large excerpt of alloying elements, over 99 % for Mo, Co and W, 45 % for Cr and 22 % for V
Geological characteristics of the Lisina phosphate deposit near Bosilegrada
No full textThe Lisina phosphate deposit is located in southeastern Serbia, on the territory of Bosilegrad, close to the Serbian-Bulgarian border. Genetically, the Lisina phosphate deposit belongs to metamorphic deposits. The narrower area of the deposit is made up of metamorphic rocks with an intensive presence of granitoid rocks. Phosphorites occur in the contact zone of the Meta sandstones that make up the basement and the sericite-chlorite slates with intercalations of marble and calcschist in the roof. Raw phosphates can be applied with positive effects as a fertilizer in the territory of the Republic of Serbia, where acidic soils normally prevail in over 50% of the territory.
At the end of 1966, the first calculation of ore reserves was made in the Lisina phosphorite deposit. In March 1974, based on this study, a new calculation of mineral reserves was started, and on December 31, 1975.the following balance reserves of phosphorite ore were determined, total (A+B+C1 category) - 68,384,477 t of ore with 9.83% P2O5.
In 1999, ITNMS from Belgrade launched an initiative to open and exploit the Lisina deposit.The survey of the Lisina deposit itself, including the calculation of reserves, was carried out by Geozavod-IMS.After a detailed analysis of the existing geological documentation, it was determined that surface exploitation would be possible in a part of the outcrop zone of the Lisina deposit, in the Panjevica (Ledine) location. The phosphate layer is located under a relatively thin (0.2-1m) deluvial cover, covered by forest, so the location is ideal for surface mining. During the aforementioned recalculation of ore reserves in 1999 (locality of Panjevica), category B ore reserves of 1,231,331t with 13.94 P2O5% were obtained, which would be exploited in the future surface mine.
Institute for technology nuclear and the other raw materials Belgrade, conducted a study in 2008, [3]about the possibility of opening the deposit Lisina and producing concentrate of the phosphate. In this article, in addition to the geological characteristics of the Lisina deposits, the results of the technological tests of samples of the phosphate mineral raw material - apatite are also given. The obtained results showed that their application increased the pH of acidic soils (especially in combination with pure calcium carbonate) and increased the yield of experimental agricultural crops
Leaching of antimony from water bottle materials
No full textAntimony oxide is frequently used as a catalyst in the production of polyethylene terephthalate (PET), which may result in the migration of antimony from packaging into bottled water. Considering the potentially toxic effects of long-term exposure to antimony, investigating its migration from packaging to water is essential.1,2 This study focused on comparing antimony migration from PET and glass packaging in commercially available bottled waters. In July 2024, we analyzed five commercially available brands of bottled water (Knjaz Miloš, Voda voda, Rosa, Aqua viva and Life) in PET and glass packaging. The aim was to quantify and compare the concentrations of antimony and other elements (Ba, Cd, Cr, Cu, Li, Pb, Sb, Sr, B, Mn, K, Mg, Na, Ca) using inductively coupled plasma mass spectrometry (ICP-MS). The analysis confirmed the leaching of antimony from PET packaging into water, while the antimony concentration in water from glass packaging remains unchanged. This migration is linked to the use of antimony oxide as a catalyst in PET production, whereas glass packaging does not contribute to an increase in antimony levels
Bentonite Modified with Surfactants—Efficient Adsorbents for the Removal of Non-Steroidal Anti-Inflammatory Drugs
No full textOrganobentonites have been applied for the removal of two common non-steroidal anti-inflammatory drugs, ibuprofen (IBU) and diclofenac sodium (DS), from aqueous solutions. Two surfactants, one with and the other without benzyl group (octadecyldimethylbenzylammonium chloride, ODMBA, and hexadecyltrimethylammonium bromide, HDTMA), in amounts equivalent to 50, 75, and 100% of the cation exchange capacity of bentonite were used for the preparation of organobentonites. Successful modification of bentonite was confirmed by several methods: X-ray powder diffraction (XRPD), point of the zero charge (pHPZC), determination of exchanged inorganic cations in bentonite, determination of textural properties, and scanning electron microscopy (SEM). Kinetic and thermodynamic data on the adsorption of IBU and DS showed that drug adsorption was controlled by the type and the amount of surfactant incorporated into the bentonite and by their arrangement in the interlayer space and at the surface of organobentonites. The adsorption of both drugs increased with an increase in the amount of both surfactants in organobentonites. The presence of the benzyl group in organobentonites enhanced the adsorption of IBU and DS and was more pronounced for IBU. Drug adsorption fits the pseudo-second-order kinetic model the best. The thermodynamic data revealed that the adsorption process was endothermic in nature and with increase of the amount of both surfactants drug adsorption processes were more spontaneous. The results obtained from this study revealed that adsorbents based on surfactants modified bentonite are promising candidates for IBU and DS removal from contaminated water
Efficient Removal of Water Soluble Fraction of Diesel Oil by Biochar Sorption Supported by Microbiological Degradation
No full textThe contamination of the water bodies by diesel oil (DO) and its water-soluble fraction (WSF) represents one of the most challenging tasks in the management of polluted water streams. This paper contains data related to the synthesis and characteristics of the plum stone biochar material (PmS-B), which was made from waste plum stones (PmS), along with its possible application in the sorption of the WSF of DO from contaminated water. Techniques applied in sample characterisation and comparisons were: Elemental Organic Analysis (EOA), Scanning Electron Microscopy−Energy Dispersive X-ray Spectroscopy (SEM-EDX), Fourier Transform Infrared Spectroscopy (FTIR), pH (pHsus) and point of zero charge (pHpzc). In order to increase the overall efficiency of the removal process, sorption and bioremediation were subsequently combined. Firstly, PmS-B was used as a sorbent of WSF, and then the remaining solution was additionally treated with a specific consortium of microorganisms. After the first treatment phase, the initial concentration of diesel WSF was reduced by more than 90%, where most of the aromatic components of DO were removed by sorption. The sorption equilibrium results were best fitted by the Sips isotherm model, where the maximum sorption capacity was found to be 40.72 mg/g. The rest of the hydrocarbon components that remained in the solution were further subjected to the biodegradation process by a consortium of microorganisms. Microbial degradation lasted 19 days and reduced the total diesel WSF concentration to 0.46 mg/L. In order to confirm the non-toxicity of the water sample after this two-stage treatment, eco-toxicity tests based on a microbial biosensor (Aliivibrio fischeri) were applied, confirming the high efficiency of the proposed method
Luminescent fluoroapatite nano-biomaterial for labeling yeast cells as an innovative approach for identification, imaging and monitoring
No full textINTRODUCTION: The ubiquity of pathogenic yeast species in the human body and the increasing number of immunocompromised people acquiring infections have drawn attention to fungal infections [1]. Improved diagnostic imaging techniques and tools to study infection are necessary due to the commensal nature of pathogens yeast and the severity of the diseases they cause. The ability to label non-pathogenic yeast cells, such as the budding yeast Saccharomyces cerevisiae (S. cerevisiae), may facilitate the identification and monitoring of these microbes in different environments. The topic of interest in this research is the development of luminescent nano-biomaterials based on fluorapatite as a contrast agent for labeling and imaging S. cerevisiae. EXPERIMENTAL (or Materials and Methods): The method used to manufacture fluorapatite nanopowder has been previously reported in research [2]. After being acquired locally, S. cerevisiae was suspended in saline. One milligram of the FAP sample was added to the yeast suspension. After mixing the resultant suspension, it was left to incubate at room temperature for one hour without being stirred. Following treatment, cells were taken out, preserved, and prepared in triplicate for microscopy. MIPAR software has been used to analysethe obtained images. RESULTS AND DISCUSSION: Luminescent FAP nanoparticles were synthesized by precipitation and centrifugation at low temperature. The resulting single-phase nanomaterial exhibits cascade fluorescence in the violet and blue regions [2]. To investigate the performance of FAP nanoparticle fluorophores, cells of S. cerevisiae were labeled and observed with a Leica DMIL inverted fluorescence microscope. Nanofluoroapatite fluorophores were successfully labeled S. cerevisiae cells.MIPAR image analysis software extracted the luminescence of nano-biomaterials from yeast cells. CONCLUSIONS: In this study, S. cerevisiae was used as a yeast model which, after labelling with a fluorapatite-based contrast agent, showed luminescent properties. The cascading nature of the agents' luminescence will allow us to monitor cellular uptake as well as monitoring cellular localization in future studies