Vojka Gardic

Mrs. Vojka Gardic

Waste management, Mining and Metallurgy Institute Bor, Bor, Serbia
orcid

Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

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

Representative Publications

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27 August 2020 in Applied Sciences
Verified
Journal Article
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RMRadmila Markovic
Radmila Markovic
MBMasahiko Bessho
Masahiko Bessho
NMNobuyuki Masuda
Nobuyuki Masuda
ZSZoran Stevanovic
Zoran Stevanovic
DBDragana Bozic
Dragana Bozic
Vojka GardicVojka Gardic
Vojka Gardic
The possibility of metal removal from the real acid mine drainage (AMD) in the area of copper ore mines in the southeast Serbia, was investigated through a combination of neutralization and adsorption methods. This approach of metal removal from AMD includes a two-step neutralization method in the first phase, aiming to separate metals as sludge. The results of laboratory test revealed that more than 99 mass % of Fe is removed up to pH 4 and more than 99 mass % of Cu up to pH 7. Based on the results obtained in laboratory conditions, a test on a semi industrial plant was carried out. The two-step neutralization separately removed Fe and Cu at pH 4 and 7, respectively. Especially, the obtained sludge at pH 7 included 1.24 mass % of Cu, much higher than usual Cu ore. Chitosan was applied for dissolved Mn removal from treated AMD. After 24 h incubation, 70 mass % of Mn is removed from the treated AMD at pH 7.4. Mn concentration was reduced from approx. 35 mg L−1 to 5 mg L−1. These results have indicated that a combination of neutralization and adsorption methods could be used effectively for metal removal from real AMD.

31 July 2021 in Water Resources Management
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Journal Article
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ZŠZoran M. Štirbanović
Zoran M. Štirbanović
Vojka GardicVojka Gardic
Vojka Gardic
Dragisa StanujkicDragisa Stanujkic
Dragisa Stanujkic
RMRadmila Markovic
Radmila Markovic
JSJovica Sokolović
Jovica Sokolović
ZSZoran Stevanovic
Zoran Stevanovic

1 January 2022 in Hemijska industrija
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VTVanja S. Trifunović
Vanja S. Trifunović
SMSnezana Milic
Snezana Milic
LALjiljana Avramovic
Ljiljana Avramovic
RJRadojka Jonovic
Radojka Jonovic
Vojka GardicVojka Gardic
Vojka Gardic
SDSilvana Dimitrijevic
Silvana Dimitrijevic
Dust from an electric arc furnace is formed as the main by-product of the steel production process from the secondary iron-based raw materials. This dust has significant contents of Zn and Fe, as well as Pb, Cd, Ca, Mg, Cr, Mn, Si, Ni, Cu, F, Cl and other elements and is considered hazardous industrial solid waste since it contains heavy metals. In order to protect the environment and public health from the negative impact of this type of hazardous waste, it is necessary, even mandatory, to carry out its treatment in accordance with the legislation of the country where it is located. Before applying any treatment of the electric arc furnace (EAF) dust, it is necessary to perform its detailed characterization. In this paper, the following characterization of EAF dust originating in the Republic of Serbia was performed: physical-mechanical and chemical characterization, determination of granulometric composition, and mineralogical characterization. Also, the EAF dust impact on the environment and human health was assessed (Leachability and Toxicity Characteristic Leaching Procedure (TCLP) tests). The results have shown that the Zn content is in the range 32 to 35 % and that the main mineralogical phases of the dust are zincite, franklinite, magnetite, and magnesioferrite. Granulometric analysis has shown that 80 % of the sample consists of particles less than 26 ?m in size. According to the leaching test results, the EAF dust is characterized as a hazardous waste due to the increased chloride content, while the TCLP test indicated dust toxicity due to the increased contents of Zn, Cd, and Pb.

1 January 2015 in Hemijska industrija
Verified
Journal Article
Open access
Vojka GardicVojka Gardic
Vojka Gardic
JPJelena Petrovic
Jelena Petrovic
LDLidija Djurdjevac-Ignjatovic
Lidija Djurdjevac-Ignjatovic
SKSrdjan Kolakovic
Srdjan Kolakovic
SVSvetlana Vujovic
Svetlana Vujovic
Mining and copper production in Bor, in the past hundred years, had a huge impact on the environment of town, but also in a wide region. In the area of Bor, in the zone of Mining and Smelting Company (RTB) activity, over 29,000 ha of land under forests and fields is degraded. The area of degraded agricultural land in the Bor municipality is over 60% of total agricultural land. Wastewater, generated in the sites of RTB Bor, pollute the Bor River and Krivelj River, which still flow into the Timok River and Danube River. These pollutions are often presented by low pH value, increased content of heavy metal ions, suspended particles and fine particles of flotation tailings, which is deposited in the valleys of these rivers on the area of over 2000 hectares. During the decades of exploitation of ore from the open pit Bor at different locations ("Visoki Planir" - also called ?Ostreljski planir?, "Severni planir" dump of ore body "H" (RTH)) gangue and tailings were delayed. The largest amount of tailings, about 150 million tons, was postponed on location Visoki planir. The effect of the mining waste and the impact of the whole process of processing copper ore to the final products on the environment, was conducted during the 4th study period of the project "Management of mining waste-tailing dump in the Bor region," supported by the Japan Society for the Promotion Science (Eng. Japan Society for the Promotion of Science) and the Japan international cooperation Agency and the Ministry of environment, Mining and Spatial planning of the Republic of Serbia. Influence of season on the level of pollutants in soil and water, the impact on water quality in the river Timok and the River Danube, was conducted during first three periods of project. This paper presents the results of the third study period. The third period of research, which was conducted over a period of 17. 10. 2012 to 17. 01.2013 year, included a review of pollution sources and define their impact on the environment. The study included the following sources of pollution: mining waste and drainage water originating from the active mine (Bor pit , field 1 Krivelj large tailings, flotation tailings in Bor RTH, metallurgical water), as well as the drainage water from the flotation tailings, which are no longer in operation (field 2 flotation tailings Great Krivelj, drainage water from the old Bor flotation tailings), the old inactive landfill mine gangue (Saraka landfill, Veliki planir - tailings from the old Bor mine, landfill mine gangue from mine RTH) and the city - urban waste water, which are discharged without treatment directly into the watercourse Bor River. Wastewater directly pollute Bor River and Krivalj River.

29 May 2024 in Metals
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Journal Article
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RMRadmila Markovic
Radmila Markovic
VMVesna Marjanovic
Vesna Marjanovic
ZSZoran Stevanovic
Zoran Stevanovic
Vojka GardicVojka Gardic
Vojka Gardic
JPJelena Velibor Petrovic
Jelena Velibor Petrovic
Bernd FriedrichBernd Friedrich
Bernd Friedrich
This paper considers the impact of copper mining-influenced water and metallurgical wastewater on the surface water in the Bor area, Serbia. Sampling, realized through the four campaigns (2020–2021), confirmed that both types of water, discharged without appropriate treatment in the Bor River, had a signific impact on the concentration of metal ions, pH and electrical conductivity on the watercourse in the Bor area. The highest concentrations of the following metal ions, Cu—271 mg/L, As—25,991 μg/L, Ni—13,856 μg/L, Cd—2627 μg/L, and Pb—2855 μg/L, were registered in the metallurgical wastewater samples. After changes occurred in the copper production process by stopping the discharge of untreated wastewater into the Bor River, the concentrations of monitored elements were drastically decreased. In the period 2022–2024, the concentration values for Cu, As and Pb ions were below the maximum allowable value, and the concentration values of Ni and Cd ions were also decreased. The values for pH and electrical conductivity were in the maximum allowable range. The return of wastewater to the copper production process would lead to both a reduction in the primary water consumption and reduction in the negative impact on the environment.

1 January 2015 in MATERIALS TRANSACTIONS
Verified
Journal Article
Closed access
RMRadmila Markovic
Radmila Markovic
Vojka GardicVojka Gardic
Vojka Gardic
LOLjubisa Obradovic
Ljubisa Obradovic
SDStefan Djordjievski
Stefan Djordjievski
ZSZoran Stevanovic
Zoran Stevanovic
MGMilica Gvozdenovic
Milica Gvozdenovic