Gordana Obrad Milentijević

Ms. Gordana Obrad Milentijević

orcid

Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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8 June 2022 in Polish Journal of Environmental Studies
Verified
Journal Article
Closed access
JGJovana Galjak
Jovana Galjak
JDJelena Djokic
Jelena Djokic
IDIrma Dervišević
Irma Dervišević
GMGordana Obrad Milentijević
Gordana Obrad Milentijević
MMMiljan Mojsić
Miljan Mojsić
BŽBojana Živković
Bojana Živković
This paper refers to the distribution of heavy metals in soil located near the Gornje Polje flotation tailings in Zvečan, in North Kosovo. Physical and chemical properties, determination of total metal concentration by acid digestion and sequential extraction scheme according to BCR (Community Bureau reference) were applied to soil samples. X-Ray diffractometry and inductively coupled plasma-optical emission spectrometry (ICP-OES) was used to analyze soil samples. The obtained results showed that the flotation tailings Gornje Polje still contain quite significant amounts of solid waste, which can release heavy metals into a potential source of pollution. The ratio between the mean concentrations of the tested metals was determined in the order: Pb (3862 mg/kg)>Zn (950.45 mg/kg)>Cu (386.75 mg/kg)> As (365.47 mg/kg)>Ni (220.87 mg/kg)>Cd (23.63 mg/kg). Pb, Zn and Cd showed the highest oncentrations in mobile fractions in soil, compared to other metals. According to the calculated index of potential environmental risk, it was confirmed that the mobility of Cd has a great impact on the environment. The order of potential environmental risk is Cd>As>Pb for all samples of the analyzed soil, and the most polluted places are near the tailings.

24 May 2022 in Minerals
Verified
Journal Article
Open access
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JDJasmina Vasic Dedic
Jasmina Vasic Dedic
JDJelena Djokic
Jelena Djokic
JGJovana Galjak
Jovana Galjak
GMGordana Obrad Milentijević
Gordana Obrad Milentijević
DLDragan Dragoslav Lazarevic
Dragan Dragoslav Lazarevic
MLMilena Lekic
Milena Lekic
The aim of this study is to investigate the environmental risk of long-term metallurgical waste disposal. The investigated site was used for the open storage of lead and zinc waste materials originating from a lead smelter and refinery. Even after remediation was performed, the soil in the close vicinity of the metallurgical waste deposit was heavily loaded with heavy metals and arsenic. The pollutants were bound in various compounds in the form of sulfides, oxides, and chlorides, as well as complex minerals, impacting the pH values of the investigated soil, such that they varied between 2.8 for sample 6 and 7.34 for sample 8. In order to assess the environmental risk, some eight soil samples were analyzed by determining the total metal concentration by acid digestion and chemical fractionation of heavy metals using the BCR sequential extraction method. Inductively coupled plasma optical emission spectrometry (ICP-OES) was used to determine six elements (As, Cd, Cu, Pb, Zn, and Ni). Total concentrations of the elements in the tested soil samples were in the range of 3870.4–52,306.18 mg/kg for As, 2.19–49.84 mg/kg for Cd, 268.03–986.66 mg/kg for Cu, 7.34–114.67 mg/kg for Ni, 1223.13–30,339.74 mg/kg for Pb, and 58.21–8212.99 mg/kg for Zn. The ratio between the mean concentrations of the tested metals was determined in this order: As > Pb > Zn > Cu > Ni > Cd. The BCR results showed that Pb (50.7%), Zn (49.2%), and Cd (34.7%) had the highest concentrations in mobile fractions in the soil compared to the other metals. The contamination factor was very high for Pb (0.09–33.54), As (0.004–195.8), and Zn (0.14–16.06). According to the calculated index of potential environmental risk, it was confirmed that the mobility of Pb and As have a great impact on the environment.

5 March 2024 in Processes
Verified
Journal Article
Open access
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MVMarija M. Vuksanović
Marija M. Vuksanović
MMMilena Milošević
Milena Milošević
IDIvan Dimitrijevic
Ivan Dimitrijevic
GMGordana Obrad Milentijević
Gordana Obrad Milentijević
BBBabincev Babincev
Babincev Babincev
Milutin M. MilosavljevićMilutin M. Milosavljević
Milutin M. Milosavljević
The increase in waste polymer recycling has helped in promoting sustainability, and together with the use of renewable raw materials, it has become a widespread concept with positive effects on both the economy and ecology. Accordingly, the aim of this study was the synthesis of “green” plasticizers, marked as LA/PG/PET/EG/LA, formed from waste poly(ethylene terephthalate) (PET) and bio-based platform chemicals propylene glycol (PG) and levulinic acid (LA). The structure of the obtained plasticizers was complex, as confirmed by results from nuclear magnetic resonance (NMR) and Fourier-transform infrared spectroscopy (FTIR) analysis. The LA/PG/PET/EG/LA plasticizers and waste poly(vinyl chloride) (PVC) were used in an optimized technology for PVC re-granulate production. The hardness of the PVC-based material with “green” plasticizers, in comparison to commercial plasticizer dioctyl terephthalate (DOTP), increased by 11.3%, while migration decreased. An improved material homogeneity and wettability of the fibers by the matrix were observed using SEM analysis of the material’s fracture surface, with a higher efficiency of intermolecular interactions leading to better mechanical performances of the newly designed materials. Thus, LA/PG/PET/EG/LA are unique materials with good compounding and plasticizing potential for PVC, as revealed by differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). In that manner, the use of bio-renewable resources and recycled polymers will contribute to diminishing waste polymer generation, contributing to a lower carbon footprint.

30 April 2025 in Processes
Verified
Journal Article
Open access
PDF file
JDJasmina Vasic Dedic
Jasmina Vasic Dedic
JDJelena Djokic
Jelena Djokic
GMGordana Obrad Milentijević
Gordana Obrad Milentijević
IDIrma Dervisevic
Irma Dervisevic
MPMaja Petrović
Maja Petrović
The historical industrial waste deposit Gater was used to dispose of different metallurgy wastes from lead and zinc production. The metallurgical waste deposit was situated in the open space, between the tailing waste deposit Žitkovac and river Ibar flow. Large amounts of lead-containing wastes are produced in the non-ferrous metallurgical industry, such as lead ash and lead slag generated in Pb smelting, lead anode slime, and lead sludge produced in the raw lead refining process. In addition to the lead concentration, numerous valuable components are found in the lead refinery waste from the group of Critical Raw Materials, such as antimony, arsenic, bismuth, copper, nickel, magnesium, scandium, as well as Rare-Earth Elements. Samples with eight characteristic points were taken to obtain relevant data indicating a possible recycling method. The chemical composition analysis was conducted using ICP; the scanning was completed using SEM-EDS. The mineralogical composition was determined by using XRD. The chemical analysis showed a wide range of valuable metal concentrations, from Ag (in the range from 14.2 to 214.6, with an average 86.25 mg/kg) to heavy metals such as Cu (in the range from 282.7 to 28,298, with an average 10,683.7 mg/kg or 1.0683% that corresponds to some active mines), Ni and Zn (in the range from 1.259 to 69,853.4, with an average 14,304.81 mg/kg), Sc (in the range from 2.4 to 75.3, with an average 33.61 mg/kg), Pb (in the range from 862.6 to 154,027.5, with an average 45,046 mg/kg), Sb (in the range from 51.7 to 18,514.7, with an average 2267.8 mg/kg), Ca (in the range from 167.5 to 63,963, with an average 19,880 mg/kg), Mg (in the range from 668.3 to 76,824.5, with an average 31,670 mg/kg), and As (in the range from 62.9 to 24,328.1, with an average 5829.53 mg/kg). The mineralogy analysis shows that all metals are in the form of oxides, but in the case of As and Fe, SEM-EDS shows some portion of elemental lead, pyrite, and silica-magnesium-calcium oxides as slag and tailing waste residues. The proposed recovery process should start with leaching, and further investigation should decide on the type of leaching procedure and agents, considering the waste’s heterogeneous nature and acidity and toxicity.

1 January 2026
Verified
Conference Paper
Closed access
PDF file
JGJovana Galjak
Jovana Galjak
MKMiljana Krstić
Miljana Krstić
SMSvetomir Milojević
Svetomir Milojević
GMGordana Obrad Milentijević
Gordana Obrad Milentijević
A modified BCR (Bureau of Community Reference) sequential extraction procedure and the potential ecological risk index method were applied to assess the ecological behavior and potential risks of metals in soil. Inductively coupled plasma optical emission spectrometry (ICP-OES) was used for sample analysis. The mean concentrations of the analyzed metals followed the order: Pb > Cu > As > Ni > Cd. The highest proportions in the mobile fractions were observed for Pb and Cd compared to the other metals. Based on the calculated potential ecological risk index, Cd was identified as having a pronounced impact on the environment due to its high mobility. The order of potential ecological risk was: Cd > As > Pb across all analyzed soil samples, with the highest levels of contamination detected in the immediate vicinity of the tailings dump. The obtained results indicate that the flotation tailings at the Gornje Polje site still contain significant amounts of material that may act as a potential source of heavy metal release into the environment.