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Assessment of microplastics content in (sub)urban soils of Serbia and its correlation with Cd, As, and Pb mobility to the Capsella bursa-pastoris (L.) Medic
No full textThis study investigates the presence of microplastics (MP) in the soil of (sub)urban areas of Serbia and its correlation with the mobility of toxic metals (Cd, As, Pb) to the plant species Capsella bursa-pastoris (L.) Medic. The density separation method with two-phase digestion (H2O2 and NaClO) was employed to optimize MP detection in soil samples. Eight different types of polymers were identified through ATR-FTIR spectroscopy analysis, consequently polystyrene and phosphorylated cardanol prepolymers being the most prevalent. The results of this study reveal significant positive correlations between the presence of MP and the availability of Cd, As, and Pb to plant, suggesting a potential role of MP in the mobility of these heavy metals in soil. Additionally, a connection was established between concentration of cadmium (Cd) in under and above-ground tissues of C. bursa-pastoris and the concurrent presence of microplastics (MP) within the soil. This correlation indicates an increased mobility of cadmium in the presence of microplastics. Conversely, the Pb content in plants showed a negative correlation with the presence of MP in the soil, indicating complex interactions between these factors
Одржива производња у електрoлучним пећима користећи принципе индустрије 4.0
No full textКористећи принципе Индустрије 4.0 и циркуларне економије, у овој студији
користи се метода машинског учења код процеса топљења челичног отпада у еле-
ктролучним пећима ради одрживе производње челика. Фокусира се на балансирање
материјалне и енергетске ефикасности, посебно на управљање деградације елемената
као што су манган и силицијум. Поред тога, овај приступ ублажава ограничења
рециклирања ефективним смањењем акумулације бакра и калаја у крајњем производу,
чиме се побољшава његов укупни квалитет. На тај начин, не само да се оптимизује
ефикасност процеса, већ се доприноси и смањењу угљеничног отиска индустрије че-
лика, усклађујући се са глобалним тежњама ка декарбонизацији и унапређењу одрживе
производне праксе.Employing Industry 4.0 and circular economy principles, this study leverages
machine learning in Electric Arc Furnaces steel waste recycling to enhance sustainable steel
production. It focuses on balancing material and energy efficiency, particularly managing
degradation elements like Mn and Si. In addition, the approach mitigates recycling limitations
by effectively reducing the accumulation of Cu and Sn in the end product, thus enhancing its
overall quality. This approach not only optimizes the process efficiency but also contributes
to the reduction of the steel industry's carbon footprint, aligning with global decarbonization
efforts and advancing sustainable manufacturing practices
Possibility of biodegradation of cotton membrane containing TEMPO radical and citric acid
No full textCotton-based membranes, due to their exceptional biocompatibility and sustainability,
have attracted considerable attention in various applications, especially in the field of bio and
green technologies. This study investigates the biodegradation potential of cotton membranes
modified with TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) radical and citric acid (CA),
with the aim of improving their properties and facilitating environmentally friendly disposal.
TEMPO radicals, in conjunction with the crosslinker citric acid, are incorporated into the
cellulose structure through a novel modification process. The citric acid component acted as a
plasticizer, increasing the amorphous parts of the cellulose and promoting enzymatic attack.
The TEMPO radical, with its nitroxyl group, contributed to the oxidation of cellulose, further
facilitating biodegradation.
The biodegradation aspect of these modified membranes was investigated in
controlled environmental conditions (Soil Burial test), simulating natural scenarios (humidity,
influence of enzymes, and bacteria). Biodegradation parameters such as weight loss,
structural changes, and degradation kinetics were examined during 90 days. Characterization
of the structure was performed using FTIR and SEM methods.
Our findings suggest that cellulosic membranes possess complete (100%)
biodegradability after 70 days compared to unmodified membranes. Obtained result shed
light on the potential of membranes modified in this way as sustainable and biodegradable
alternatives in various applications. The results emphasize their ecological nature and ability
to reduce environmental stress. Such cellulose-based materials promise a much greener future
in biotechnology, healthcare, and environmental protection
Investigation in order to define the technological process of obtaining fillers for use in various industries on the basis of limestone “Glavatske Kuće”-Kotor
No full textThis paper presents results of investigations of the possibility of using “Glavatske Kuće”-Kotor limestone (Montenegro) as filler in various industry branches. Micronization methods, granulometric composition, oil and water absorption and degree of whiteness were investigated, and chemical and thermal analyses (DT/TG) were performed. Physico-chemical properties of this limestone classify it among high quality carbonate raw materials with relatively high CaCO3 content of 97.68 %, as well as low MgCO3 content of 1.849 % and low silicate content (SiO2 0.24 %). Its quality satisfies requirements of standards on using of calcium carbonate as filler in industry of paints and coatings; glass industry; foundry industry; sugar industry and metallurgy. Due to the low degree of whiteness (77,85 %) “Glavatske Kuće” limestone cannot be used in pharmaceutical and cosmetics industry, paper industry. Because of increased MgO content, limestone “Glavatske kuće” cannot be used in the fertilizers industry. Due to relatively high content of heavy metals, Cu (47 ppm), Ni (50 ppm) and Cd (8 ppm), as well as biogenic elements P2O5 (0.0234 %), K2O (0,0157 %), “Glavatske Kuće” limestone cannot be used in production of cattle feed and for neutralization of acidic soils
Limestones of Platac technical-building stone deposits as carbonate raw materials
No full textTechnical-building stone is a carbonate raw material that has unlimited potential in Montenegro and is one of the most important mineral raw materials. A special valorization of rocks with a carbonate composition, primarily limestone, is the production of carbonate fillers and their application in various branches of industry. The paper presents the results of multi-year geological investigations of the limestone deposits of Platac, the established reserves, the quality and the possibility of applying limestone
Designing biocompatible titanium alloys: machine learning approach
No full textTitanium and its various alloys have been used for decades as for numerous dental and orthopedic devices. What makes it suitable for these applications is the excellent combination of biocompatibility, corrosion resistance, low modulus of elasticity and specific strenght. However, recent reasrches have linked some of the main alloying elements, aluminium and vanadium, and several other elements besides them, with a very harmful effect on human body. Stress shielding is another possible side effect due to the still insufficiently matched elastic modulus of the alloy and bone. These issues have demanded the exploration for alternative alloys, characterized by non-toxic components and low elastic modulus. The design of titanium alloys involves a variety of tehniques, such as Mo equvivalent method, the electron-to-stom ratio (e/a), d electron based alloy design, experimental tehniques, and cutting-edge machine learning approches. The study leverges the Extra Tree Regression from machine learning to analize the most influential parameters for the elastic modulus, identifying the specific heat and shear of the silicon in alloy as significant factors. Multi-component diagrams were subsequently constructed to guide the development of alloys with a low elastic modulus. Also, employing the development model with the Monte Carlo experimental design method we found optimal compositions for high entropy alloys with a low Young’s modulus. These finding provide a solid soundation for future experimental studies on biocompatible titanium alloys
Geologija ležišta zeolitskih tufova Srbije
No full textZeoliti čine grupu prirodnih i sintetičkih neorganskih jedinjenja, koja poseduje specifične fizičko-hemijske osobine pogodne za industrijsku primenu. Zeolit, ""kamen koji ključa"" (grčki zeo = ključa; lithos =stena) je naziv za određenu vrstu prirodnih alumosilikatnih minerala, koji je potekao od švedskog mineraloga Kronšteda davne 1756. godine. Prema genezi, raznovrsnosti hemijskog sastava, strukturnim karakteristikama i primeni, zeoliti čine specifičnu grupu alumosilikatnih minerala u okviru grupe tektosilikata. Prirodni zeoliti se javljaju kao vodeni alumosilikati alkalnih i zemno-alkalnih metala. Prirodna zeolitska sirovina predstavlja za sebe rudnu stenu, koja sadrži zeolite, najčešće hojlanditske, šabazitske ili analcimske serije, do 80-95% sa mineralnim primesama vezanim za genezu datog ležišta. Stene koje sadrže zeolit, posle usitnjavanja i sejanja na frakcije određene krupnoće, u većini slučajeva bez obogaćivanja i druge bilo kakve prerade, koriste se kao gotov produkt u raznim granama industrije i poljoprivrede. Data je detaljna geološka karakterizacija prirodnih zeolita najznačajnijih srpskih ležišta. Veliki broj pojava i ležišta prirodnih zeolita piroklastičnog porekla (zeolitskih tufova) široko rasprostranjenih u miocenskim sedimentima Srbije kao što su: Zlatokop (Vranjski basen), Igroš, Jablanica 1 (Kruševački basen), Beočin (Fruška Gora), Toponica (Kosovska Kamenica) i Slanci (Dunavski ključ kod Beograda) predstavljaju ekonomski veoma važnu mineralnu sirovinu. Osnovni korisni mineral je HEU-tipa i uglavnom se radi o klinoptilolit-hojlanditskoj mineralnoj seriji
Influence of type and quantity of filler on change of density of sulfur concrete
No full textConcrete is a material that has been used for centuries and is often modified using polymers. In the last fifty years, synthetic polymers have been used for the modification of concrete, but also for the production of concrete. In recent decades, sulfur concrete has been an interesting product that can be used mainly in low-rise construction due to its characteristics. In this work, we used the starting mixture for the preparation of sulfur concrete (sand, elemental sulfur with the addition of modified sulfur and fillers) heated to a temperature of 120 ºC to 170 ºC and homogenized. The results of previous research on the production of sulfur concrete showed that the density of the obtained product changes depending on the type as well as the amount of filler added to the basic mixture based on raw materials. Talc, microsilicon, plate alumina and fly ash were used as fillers. The amounts of fillers were 0%, 1%, 3%, 5%, 7% and 10%
Bentonite clays as aflatoxin B1 adsorbents
No full textIn this study three bentonite clays (bentonite from deposit Beretnica in Republic of Serbia, commercial bentonite and gray
clay from Šipovo deposit in Bosnia and Herzegovina) were investigated as adsorbents of aflatoxin B1 (AFB1). In a single
in vitro AFB1 adsorption experiment, all three bentonites showed high adsorption efficiency for AFB1 at pH 5. The effect
of adsorbent mass on AFB1 adsorption was also studied, with the same initial AFB1 concentration, at pH 3, and it was
shown that toxin adsorption decreased with decreasing amount of each bentonite in suspension. Thermal analysis was
performed in order to determine the structural differences between investigated bentonites. Results showed that gray clay
was trans-vacant bentonite while other two clays were cis-vacant bentonites. Aflatoxin B1 adsorption experiments, at pH
3, showed that trans-vacant gray bentonite had higher affinity for AFB1 than commercial cis-vacant bentonite. The
highest adsorption was achieved with cis-vacant bentonite from Beretnica deposit
Slojeviti dvostruki hidroksidi za uklanjanje boja iz otpadnih voda
No full textОтпадне воде представљају велики еколошки притисак на читав екосистем.
Загађујуће материје у отпадној води, као што су боје, могу изазвати токсичне после-
дице по живи свет. Из тог разлога је потребно развити нове, ефикасне материјале који
у процесу адсорпције могу да уклоне присутне полутанте и реше проблем загађења.
Слојевити двоструки хидроксиди добијени процесом таложења при ниском преза-
сићењу примењени су у процесу уклањања боје метанил-жуто из водених раствора.
Приликом експеримената, варирани су параметри као што су маса адсорбента, време
контакта, температура. Добијеии резултати показују висок адсорпциони капацитет 74
mg g-1 и ендотермну природу процеса адсорпције.Wastewater represents a major environmental pressure on the entire ecosystem.
Pollutants in wastewater, such as dyes, can cause toxic effects on living beings. Therefore, it
is necessary to develop new, efficient sorption materials that can remove the present
pollutants and solve the pollution problem. The layered double hydroxides obtained by the
co-precipitation process at low supersaturation were applied in the process of removing methanil-yellow color from aqueous solutions. During the experiments, parameters such
as adsorbent mass, contact time, and temperature were varied. The obtained results
show a high adsorption capacity of 74 mg g-1 and an endothermic nature during
adsorption process