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Reciklaža otpada koji sadrži materijale na bazi karbonatnih mineralnih sirovina
No full textU radu je prikazan značaj reciklaže otpada na bazi karbonatnih mineralnih sirovina nastalog
u oblasti građevinarstva. Ova vrsta otpada može negativno da utiče na životnu sredinu ako
se sa njime ne postupa na propisan način. Reciklaža je jedino rešenje za smanjenje količine
građevinskog otpada koji se nalazi na deponijama. Kako bi se građevinske firme stimulisale
da prihvate reciklažu otpada, kao sastavni deo svog poslovanja, države sprovode različite
strategije za unapređenje primene reciklaže u praksi. Podsticaj reciklaže, korišćenja
sekundarnih sirovina i razvoj alternativnih tehnologija su izuzetno važni sa aspekta
održivosti prirodnih resursa koji su neobnovljivi ili teško obnovljivi. Pozitivna iskustva
razvijenih zemalja u oblasti reciklaže, mogu da nam budu dobar primer za uspešnu sanaciju
otpada i u našoj zemlji
Removal of Pb2+ from aqueous solutions by alkally activated hydrochars of the spent mushroom substrate
No full textIn this study, the adsorption capacity of Pb2+ removal from aqueous solution was examined by hydrochar of the spent mushroom substrate. In order to improve the adsorption capacity, hydrochar was previously activated with 2M KOH. The obtained results demonstrated that alkally activation increased the sorption capacity from 36 mg g-1 to 74 mg g-1. Structural characterization of activated and inactivated hydrochars were performed by FTIR analysis. Toward to obtained results of FTIR analysis, the increased of the oxygen functional groups (OFG) in activated hydrochars was perceived, which is contributed to the increase in the adsorption capacity of this carbonized material. Results indicated that spent mushroom substrate can be converted into hydrochar as a perspective sorbent for removal of Pb2+
Proizvodnja čvrstog biogoriva iz otpadne biomase postupkom hidrotermalne karbonizacije
No full textPoslednjih decenija, masovno iskorišćenje i eksploatacija fosilnih goriva dovodi do brojnih negatinih uticaja na životnu sredinu. Iz ovog razloga se se sve više teži ka implementaciji tehnologija koje bi omogućile proizvodnju biogoriva iz obnovljivih izvora. Hidrotermalna karbonizacija (HTC) je prepoznata kao jedna od visoko efikasnih i perspektivnih tehnologija za valorizaciju otpadne biomase kroz proizvodnju ugljeničnih materijala (hidročadi) široke upotrebne vrednosti. U okviru ovog rada komina grožđa je podvrgnuta HTC tretmanu na različitim temperaturama i izvršeno je ispitivanje gorivnih karakteristika dobijenih hidročadi. Rezultati su pokazali da sa porastom temperature karbonizacije rastu gornja i donja toplotna moć (od 20,40 do 26,78 MJ/kg i od 18,80 do 25,36 MJ/kg, redom), kao i energetska gustina u dobijenim hidročadima, dok istvoremeno atomski O/C i H/C odnosi, isparljive materije (sa 75,50 % na 61,22 %), i energetski prinos opadaju. Preliminarni rezultati ove studije sugerišu da dobijene hidroćadi pokazuju poboljšana gorivna svojstva u odnosu na kominu grožđa i da konverzija primenom HTC-a može biti korisna metoda za upravljanje otpadom i povrat energije iz otpadne biomase
Hemokompatibilnost antibakterijskih nanofosfora na bazi fluorapatita pripremljenog metodom precipitacije za biomedicinsku primenu
No full textLuminescent inorganic nanomaterials (nanophosphorus) based on fluorapatite (FAP) are attracting significant interest for biomedical, biotechnological and environmental applications.
Luminescent nanopowders based on fluorapatite substituted with Pr3+ and CO32-ions (PrCFAP) were obtained by a simple precipitation method. Previously published results have shown that nanopowders are monophasic and composed of nanospheres, with luminescence in violet color. Also,
nanopowders exhibit and antibacterial behavior against E. coli. In this study the results of chemocompatibility of antibacterial luminescent nanophospors obtained by precipitation for various biomedical and health applications are presented. Pure FAP showed a degree of hemolysis of 5% and can be considered chemcompatible. Doped nanopowders showed hemolysis up to about 10%. Slight hemolytic behavior of the tested PrCFAP nanopowders may be a consequence of mechanical stress of the cell in the interaction with nanoparticles, as well as the toxic effect of dissolved Pr3+ and
F- ions from the FAP lattice. The above results indicate that the antibacterial PrCFAP nanophosphorus may be future evaluated for different biomedical applications, such as agents for cells labeling, therapy and drug delivery.Luminescentni neorganski nanomaterijali (nanofosfor) na bazi fluorapatita (FAP) privlače značajno interesovanje za biomedicinske, biotehnološke i ekološke primene. Jednostavnom metodom
precipitacije dobijeni su luminescentni nanomaterijali na bazi fluorapatita supstituisani Pr3+ i CO32- jonima (PrCFAP). Ranije objavljeni rezultati su pokazali da su nanoprahovi monofazni i sastavljeni od nanosfera, sa luminiscencijom u ljubičastoj boji. Pored toga, nanoprahovi su pokazali i antibakterijsko ponašanje protiv E. coli. U ovoj studiji prikazani su rezultati hemokompatibilnosti antibakterijskih luminiscentnih nanofospora dobijenih precipitacijom za različite biomedicinske i zdravstvene primene. Čisti FAP je pokazao stepen hemolize od 5% i može se smatrati hemokompatibilnim. Dopirani nanoprahovi su pokazali hemolizu do oko 10%. Blago hemolitičko ponašanje ispitivanih PrCFAP nanoprahova može biti posledica mehaničkog naprezanja ćelije u interakciji sa nanočesticama, kao i toksičnog dejstva rastvorenih Pr3+ i F jona iz FAP rešetke. Gore navedeni rezultati ukazuju da antibakterijski PrCFAP nanofosfori u budućnosti mogu biti procenjeni za različite biomedicinske primene, kao što su agenti za obeležavanje ćelija, terapije i isporuku lekova
Recycled poly(ethylene terephthalate) based – plasticizer for PVC regranulates production
No full textDue to the increasing use and widespread of plastics, poly (ethylene terephthalate) (PET) and poly
(vinyl chloride) (PVC) are becoming one of the major threats to the environment. The aim of this
paper is obtaining plasticizers from recycled PET, and hot/cold mixing thereof with PVC to produce
new materials. Plasticizer was obtained from PET using ethylene glycol (EG) in the presence of
catalyst FASCAT 4100, followed by treatment with maleic anhydride and finally 2-ethylhexanol
(2-EtHex). The obtained glycolysate and plasticizer, individually or mixtures thereof, were used for
the production of polygranulates based on waste PVC in order to obtain an expanded mass of
homogenized PVC with glycolysate/plasticizer. The abovementioned procedures and test results for
the regranulates and products indicate that the proposed technology offers a solution to the problem
of waste PET and PVC through transesterification in order to obtain plasticizer based on PET and
EG, called 2-EtHex/MA/РG/PET/EG/MA/2-EtHex used in the processing of PVC waste and in
regranulate. The obtained regranulates are further processed by injection molding or extrusion into
commercial products such as slippers, footwear, boots, garden hoses, mats, floor mats, etc
Modification of Structural-Textural Properties of Sulfide Minerals at Polymetallic Concentrate Leaching with Sulfuric Acid and Hydrogen Peroxide Solutions
No full textThis paper examines the effects of structural-textural characteristics of sulfide minerals on their leaching from polymetallic concentrates with sulfuric acid and hydrogen peroxide solutions. The polymetallic concentrate was obtained by flotation of polymetallic ore from the Rudnik deposit in Serbia. X-ray diffraction (XRD), qualitative and quantitative mineralogical, scanning electron microscopy (SEM/EDX), and chemical analyses were used to characterize the polymetallic concentrate and leach residue. The polymetallic concentrate contained chalcopyrite, galena, sphalerite, pyrrhotite, and quartz. The total content of sulfide minerals was 69.5%, and the occurrence of free sulfide mineral grains was about 60.9%. The comprehensive thermodynamic analysis was done by HSC Chemistry (R) package 9.9.2.3 to determine optimal experimental leaching conditions. Chalcopyrite, sphalerite, and pyrrhotite oxidized during leaching, and dissolution occurred. The oxidized galena remains in the solid residual as insoluble anglesite. Also, elemental sulfur and unleached minerals of copper, zinc, and iron were found in the leach residues. It was found that the structural assembly of sulfide minerals in the leach residue is very favorable and that undissolved sulfide grains are primarily present in free form. Accordingly, there was no reason to reduce the leaching rate with time. The presence of elemental sulfur and anglesite formed in the leaching process and precipitated on the surface of mineral grains was confirmed by XRD, quantitative and qualitative mineralogical analysis, and SEM/EDX
Overview of extraction technologies and applications for metals from Balkan hyperaccumulators
No full textFitorudarenje je aktuelna biotehnologija u razvoju kojom se ekstrahuju retki i dragoceni metali iz prirodno obogaćenih ili zagađenih zemljišta uz pomoć biljaka hiperakumulatora. Na teritoriji Balkana hiperakumulatorske vrste usvajaju prevashodno nikl, cink, talijum, bakar i arsen. U ovom radu dat je pregled do sada ispitanih tehnologija za ekstrakciju ovih elemenata iz biomase hiperakumulatorskih vrsta širom sveta, kao i područja potencijalne primene dobijenih produkata. Na teritoriji Srbije fitorudarenje ima perspektivu, i potrebno je vršiti ispitivanja u pravcu pronalaženja upotrebne vrednosti dostupnih hiperakumulatora, kao i razvoja tehnologija za ekstrakciju metala iz njihove biomase.Phytomining is a currently developing biotechnology aiming to extract rare and precious metals from naturally enriched or polluted soils with the help of hyperaccumulator plants. On the territory of the Balkans, hyperaccumulating species mainly accumulate elements such as nickel, zinc, thallium, copper and arsenic. This paper provides an overview of the studied technologies around the world for the extraction of these elements from hyperaccumulator's biomass, as well as the areas of potential application of the obtained products. Phytomining has a potential for development in Serbia, and for this purpose it is necessary to utilitized available hyperaccumulators, as well as to investigate technologies for the extraction of metals from their biomass
Analysis of the Mechanism of Acid Mine Drainage Neutralization Using Fly Ash as an Alternative Material: A Case Study of the Extremely Acidic Lake Robule in Eastern Serbia
No full textAcid mine drainage (AMD) is a waste from mining sites, usually acidic, with high concentrations of sulfates and heavy metal ions. This study investigates the AMD neutralization process using fly ash (FA) as an alternative material. Samples of FA from coal-fired power plants in Serbia ("Nikola Tesla" (EF) and "Kostolac" (KOST)) were analyzed and used. The results were compared with the treatment efficiency of commercial neutralization agent (NaOH). The alkaline nature of FA was the basis for use in the treatment process of the extremely acid Lake Robule (pH 2.46), located in the mining areas of eastern Serbia. The optimal S/L ratio for the AMD neutralization process determined for EF was 25 wt.%, and for KOST it was 20 wt.%. The mechanism of the neutralization process was analyzed using the ANC test and PHREEQC program. The element concentrations and pH values in solutions indicated that FA samples could neutralize Lake Robule with more than 99% of Al, Fe, Cu, Zn, and more than 89% of Pb precipitated. Formation of insoluble (oxy)hydroxide forms (Fe3+ and Al3+ ions) creates favorable conditions for co-precipitation of other trace metals (Cu, Zn, Ni, Pb, and Cd) from AMD, which is further enhanced by cation adsorption on FA particles. FA proved to be a more effective neutralization agent than NaOH due to its adsorption effect, while among the FA samples, KOST was more effective due to the aging process through the carbonization reaction. Using FA as an alternative material is a promising and sustainable method for treating AMD, with economic and environmental benefits
Options for Hydrometallurgical Treatment of Ni-Co Lateritic Ores for Sustainable Supply of Nickel and Cobalt for European Battery Industry from South-Eastern Europe and Turkey
No full textThe automotive industry is in the process of transformation from the traditional production of vehicles with engines powered by the combustion of fossil fuels to vehicles powered by electric energy. This revolutionary transformation will generate a growing demand for metallic raw materials that are a crucial part of batteries-nickel and cobalt, among others. Providing enough raw materials for e-mobility in a sustainable way will be a challenge in the years to come. The region of South-Eastern Europe (SEE) and Turkey is relatively rich in lateritic Ni-Co deposits, and this region has the potential to partially replace the import of nickel and cobalt intermediates to the European Union from distant overseas locations. Possibilities for the sustainable sourcing of nickel and cobalt from the SEE region are reviewed in this paper, with an overview of the global demand and production of these metals, lateritic mineral resources of SEE, the current status of production, and the prospective development of nickel and cobalt production in this region
Funkcionalizacija filipsita cetilpiridinijum-hloridom i heksadeciltrimetilamonijum-bromidom i njegova potencijalna primena
No full textHemijskom modifikacijom zeolita površinski aktivnim supstancama kao što su dugolančani organski katjoni dobijaju se materijali sa hidrofobnijim površinama u odnosu na polazni zeolit koji imaju afinitet za adsorpciju slabo polarnih molekula. U ovoj doktorskoj disertaciji prirodni zeolit filipsit iz ležišta u okolini Napulja u Italiji modifikovan je površinski aktivnim supstancama cetilpiridinijum-hloridom i heksadeciltrimetilamonijum-bromidom. Dobijeni uzorci organo-filipsita su okarakterisani određivanjem specifične površine, infracrvenom spektroskopijom sa Furijeovom transformacijom (FTIC), simultanim termijskim analizama (TG/DTA), određivanjem zeta potencijala i određivanjem tačke nultog naelektrisanja. Polazni uzorak filipsita je pored ovih metoda okarakterisan i rendgensko difrakcionom (XRPD) analizom, skenirajućom elektronskom mikroskopijom sa energetski-disperzivnom rendgenskom analizom (SEM-EDS), određivanjem hemijskog sastava i određivanjem ukupnog i spoljašnjeg kapaciteta katjonske izmene. U zavisnosti od količine organskih katjona upotrebljenih za modifikaciju, na površini filipsita se formira monosloj ili dvosloj organske faze. Pri formiranju monosloja dolazi do jonske izmene neorganskih katjona na površini filipsita sa cetilpiridinijum i heksadeciltrimetilamonijum jonima, dok se pri formiranju dvosloja pored jonske izmene javljaju i hidrofobne interakcije između alkilnih lanaca organskih katjona. Pokazano je da modifikacijom nije došlo do promena osnovne strukture minerala i da su organski katjoni prisutni samo na površini filipsita. Organo-filipsiti su nakon karakterizacije ispitivani kao adsorbenti slabo polarnih organskih molekula i to: mikotoksina (zearalenon, ohratoksin A, aflatoksin B1) i lekovite supstance (natrijum diklofenak).
Zearalenon i ohratoksin A su se efikasno adsorbovali na organo-filipsitima u odnosu na polazni filipsit, koji je pokazao nisku adsorpciju ovih mikotoksina. Utvrđeno je da su organski katjoni na površini filipsita aktivna mesta na kojima se adsorbuju zearalenon i ohratoksin A, kao i da tip organskog katjona nema veći uticaj na adsorpciju ovih toksina. Za razliku od zearalenona čija je adsorpcija pH nezavisna, adsorpcija ohratoksina A zavisi od pH sredine. S obzirom da je u ispitivanjima adsorpcije mikotoksina najviše ispitivan prirodni zeolit klinoptilolit, rezultati adsorpcije na filipsitu modifikovanom cetilpiridinijum jonom su upoređeni sa rezultatima adsorpcije na klinoptilolitu modifikovanom istim organskim katjonom. Utvrđeno je da su organo-filipsiti jednako efikasni u adsorpciji zearalenona i ohratoksina A kao i organo-klinoptiloliti. Aflatoksin B1 se efikasno adsorbovao na organo-filipsitima kao i na polaznom filipsitu, što ukazuje da su adsorpcioni centri kod nemodifikovanog filipsita neorganski katjoni prisutni na površini minerala dok kod organo-filipsita organski katjoni stvaraju nove adsorpcione centre. Poredeći rezultate adsorpcije aflatoksina B1 na filipsitu i klinoptilolitu, viša adsorpcija je postignuta na klinoptilolitu, što ukazuje da na adsorpciju ovog toksina utiče i vrsta neorganskih katjona na površini zeolita a ne samo njihova količina. Međutim kada se uporedi adsorpcija aflatoksina B1 na zeolitima, filipsitu i klinoptilolitu, sa adsorpcijom na montmorilonitu uočava se znatno viša adsorpcija na montmorilonitu što je posledica razlike u strukturama ova dva minerala. Natrijum diklofenak se efikasno adsorbovao na organo-filipsitma, za razliku od polaznog filipsita koji praktično ne adsorbuje natrijum diklofenak. Za adsorpciju natrijum diklofenaka odgovorne su elektrostatičke interakcije anjonskog oblika natrijum diklofenaka i pozitivno naelektrisane „glave“ organskog katjona kao i hidrofobne interakcije između hidrofobnog dela natrijum diklofenaka i alkilnih lanaca organskih katjona. Karakterizacija organo-filipsita nakon adsorpcije natrijum diklofenaka je pokazala da su organo-filipsiti strukturno stabilni.
Organo-filipsiti dobijeni modifikacijom površine filipsita cetilpiridinijum i heksadeciltrimetilamonijum jonom su efikasni adsorbenti mikotoksina (zearalenon, ohratoksin A,
aflatoksin B1) i lekovite supstance (natrijum diklofenak) i mogli bi naći praktičnu primenu u ishrani životinja kao aditivi stočnoj hrani i u farmaciji kao nosači aktivne farmaceutske supstance.Chemical modification of zeolite with surfactants such as long-chain organic cations yields materials with more hydrophobic surfaces than the starting zeolite that have an affinity for adsorption of low polar molecules. In this doctoral dissertation, natural zeolite phillipsite from a deposit near Naples in Italy was modified with surfactants: cetylpyridinium-chloride and hexadecyltrimethylammonium-bromide. The obtained organo-phillipsite samples were characterized by determination of specific surface area, Fourier transform infrared spectroscopy (FTIR), coupled thermal analysis methods (TG/DTA), determination of zeta potential and determination of the point of zero charge. In addition to these methods, the initial phillipsite sample was characterized by X-ray powder diffraction (XRPD) analysis, scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDS), determination of chemical composition and determination of total and external cation exchange capacity. Depending on the amount of organic cations used for modification, a monolayer or bilayer of the organic phase is formed on the surface of the phillipsite. During the formation of the monolayer, ion exchange of inorganic cations on the surface of the phillipsite with cetylpyridinium and hexadecyltrimethylammonium ions occurs, while during the formation of the bilayer, hydrophobic interactions between the alkyl chains of organic cations occur in addition to the ion exchange. It has been shown that the modification did not change the basic structure of the mineral and that organic cations are present only on the surface of the phillipsite. After characterization, organo-philipsites were tested as adsorbents of low polar organic molecules: mycotoxins (zearalenone, ochratoxin A, aflatoxin B1) and drug (diclofenac sodium).
Zearalenone and ochratoxin A were efficiently adsorbed on organo-phillipsites compared to the initial phillipsite, which showed low adsorption of these mycotoxins. It was found that organic cations on the surface of philipsite are active sites where zearalenone and ochratoxin A are adsorbed, and that the type of organic cation has no major effect on the adsorption of these toxins. Unlike zearalenone, whose adsorption is pH independent, the adsorption of ochratoxin A depends on the pH of the medium. Since the natural zeolite clinoptilolite was the most investigated in mycotoxin adsorption studies, the results of adsorption on cetylpyridinium modified phillipsite were compared with the results of adsorption on clinoptilolite modified with the same organic cation. Organo-phillipsites were found to be as effective in the adsorption of zearalenone and ochratoxin A as organo-clinoptilolites. Aflatoxin B1 was efficiently adsorbed on organo-phillipsites as well as on the initial phillipsite, which indicates that adsorption centers in unmodified phillipsite are inorganic cations present on the mineral surface while in organo-phillipsites organic cations create new adsorption centers. Comparing the results of adsorption of aflatoxin B1 on phillipsite and clinoptilolite, higher adsorption was achieved on clinoptilolite, which indicates that the adsorption of this toxin is influenced by the type of inorganic cations on the surface of zeolite and not just their amount. However, when comparing the adsorption of aflatoxin B1 on zeolites, phillipsite and clinoptilolite, with the adsorption on montmorillonite, significantly higher adsorption on montmorillonite is observed due to the difference in the structures of these two minerals. Diclofenac sodium was efficiently adsorbed on organo-phillipsites, in contrast to the initial phillipsite, which practically does not adsorb diclofenac sodium. Electrostatic interactions of the anionic form of diclofenac sodium and the positively charged „head“ of the organic cation as well as the hydrophobic interactions between the hydrophobic part of the diclofenac sodium and the alkyl chains of organic cations are responsible for the adsorption of diclofenac sodium. Characterization of organo-phillipsites after adsorption of diclofenac sodium showed that organo-philipsites are structurally stable.
Organo-phillipsites obtained by modifying the surface of phillipsite with cetylpyridinium and hexadecyltrimethylammonium ion are effective adsorbents of mycotoxins (zearalenone, ochratoxin A, aflatoxin B1) and drug (diclofenac sodium) and could find practical application in animal nutrition as feed additives and in pharmacy as carriers of active pharmaceutical ingredient