TY  - JOUR
AU  - Dolić, Maja B.
AU  - Rajaković-Ognjanović, Vladana
AU  - Štrbac, Svetlana B.
AU  - Dimitrijević, Suzana I.
AU  - Mitrić, Miodrag N.
AU  - Onjia, Antonije
AU  - Rajaković, Ljubinka V.
PY  - 2017
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/858
AB  - The objective of this study was to investigate the modification of materials used in wastewater treatment for possible antimicrobial application(s). Granulated activated carbon (GAC) and natural clinoptilolite (CLI) were activated using Cu2+-and Zn2+-ions and the disinfection ability of the resulting materials was tested. Studies of the sorption and desorption kinetics were performed in order to determine and clarify the antimicrobial activity of the metal-activated sorbents. The exact sorption capacities of the selected sorbents, GAC and CLI, activated through use of Cu2+-ions, were 15.90 and 3.60 mg/g, respectively, while for the materials activated by Zn2+-ions, the corresponding capacities were 14.00 and 4.72 mg/g,. The desorption rates were 2 and 3 orders of magnitude lower than their sorption efficacy for the Cu2+-, and Zn2+-activated sorbents, respectively. The intermediate sorption capacity and low desorption rate indicated that the overall antimicrobial activity of the metal-modified sorbents was a result of metal ions immobilized onto surface sites. The effect of antimicrobial activity of free ions desorbed from the metal-activated surface may thus be disregarded. The antimicrobial activities of Cu/GAC, Zn/GAC, Cu/CLI and Zn/ CLI were also tested against Escherichia coli, Staphylococcus aureus, and Candida albicans. After 15 min exposure, the highest levels of cell inactivation were obtained through the Cu/CLI and the Cu/GAC against E. coli, 100.0 and 98.24%, respectively. However, for S. aureus and yeast cell inactivation, all Cu2+-and Zn2+-activated sorbents proved to be unsatisfactory. A characterization of the sorbents was performed by Xray diffraction (XRD), X-ray photo electron spectroscopy (XPS), and field emission scanning electron microscopy (FE-SEM). A concentration of the adsorbed and released ions was determined by inductively coupled plasma-optical emission spectroscopy (ICP-OES) and mass spectrometry (ICP-MS). The results showed that the antimicrobial performance of the activated sorbents depended on the surface characteristics of the material, which itself designates the distribution and the bioavailability of the activating agent.
PB  - Elsevier B.V.
T2  - New Biotechnology
T1  - Natural sorbents modified by divalent Cu2+- and Zn2+- ions and their corresponding antimicrobial activity
EP  - 159
SP  - 150
VL  - 39
DO  - 10.1016/j.nbt.2017.03.001
ER  - 

@article{
author = "Dolić, Maja B. and Rajaković-Ognjanović, Vladana and Štrbac, Svetlana B. and Dimitrijević, Suzana I. and Mitrić, Miodrag N. and Onjia, Antonije and Rajaković, Ljubinka V.",
year = "2017",
abstract = "The objective of this study was to investigate the modification of materials used in wastewater treatment for possible antimicrobial application(s). Granulated activated carbon (GAC) and natural clinoptilolite (CLI) were activated using Cu2+-and Zn2+-ions and the disinfection ability of the resulting materials was tested. Studies of the sorption and desorption kinetics were performed in order to determine and clarify the antimicrobial activity of the metal-activated sorbents. The exact sorption capacities of the selected sorbents, GAC and CLI, activated through use of Cu2+-ions, were 15.90 and 3.60 mg/g, respectively, while for the materials activated by Zn2+-ions, the corresponding capacities were 14.00 and 4.72 mg/g,. The desorption rates were 2 and 3 orders of magnitude lower than their sorption efficacy for the Cu2+-, and Zn2+-activated sorbents, respectively. The intermediate sorption capacity and low desorption rate indicated that the overall antimicrobial activity of the metal-modified sorbents was a result of metal ions immobilized onto surface sites. The effect of antimicrobial activity of free ions desorbed from the metal-activated surface may thus be disregarded. The antimicrobial activities of Cu/GAC, Zn/GAC, Cu/CLI and Zn/ CLI were also tested against Escherichia coli, Staphylococcus aureus, and Candida albicans. After 15 min exposure, the highest levels of cell inactivation were obtained through the Cu/CLI and the Cu/GAC against E. coli, 100.0 and 98.24%, respectively. However, for S. aureus and yeast cell inactivation, all Cu2+-and Zn2+-activated sorbents proved to be unsatisfactory. A characterization of the sorbents was performed by Xray diffraction (XRD), X-ray photo electron spectroscopy (XPS), and field emission scanning electron microscopy (FE-SEM). A concentration of the adsorbed and released ions was determined by inductively coupled plasma-optical emission spectroscopy (ICP-OES) and mass spectrometry (ICP-MS). The results showed that the antimicrobial performance of the activated sorbents depended on the surface characteristics of the material, which itself designates the distribution and the bioavailability of the activating agent.",
publisher = "Elsevier B.V.",
journal = "New Biotechnology",
title = "Natural sorbents modified by divalent Cu2+- and Zn2+- ions and their corresponding antimicrobial activity",
pages = "159-150",
volume = "39",
doi = "10.1016/j.nbt.2017.03.001"
}

Dolić, M. B., Rajaković-Ognjanović, V., Štrbac, S. B., Dimitrijević, S. I., Mitrić, M. N., Onjia, A.,& Rajaković, L. V.. (2017). Natural sorbents modified by divalent Cu2+- and Zn2+- ions and their corresponding antimicrobial activity. in New Biotechnology
Elsevier B.V.., 39, 150-159.
https://doi.org/10.1016/j.nbt.2017.03.001

Dolić MB, Rajaković-Ognjanović V, Štrbac SB, Dimitrijević SI, Mitrić MN, Onjia A, Rajaković LV. Natural sorbents modified by divalent Cu2+- and Zn2+- ions and their corresponding antimicrobial activity. in New Biotechnology. 2017;39:150-159.
doi:10.1016/j.nbt.2017.03.001 .

Dolić, Maja B., Rajaković-Ognjanović, Vladana, Štrbac, Svetlana B., Dimitrijević, Suzana I., Mitrić, Miodrag N., Onjia, Antonije, Rajaković, Ljubinka V., "Natural sorbents modified by divalent Cu2+- and Zn2+- ions and their corresponding antimicrobial activity" in New Biotechnology, 39 (2017):150-159,
https://doi.org/10.1016/j.nbt.2017.03.001 . .

TY  - JOUR
AU  - Brajović, Ljiljana
AU  - Stojanović, Dušica B.
AU  - Mihailović, Pedja
AU  - Marković, Smilja
AU  - Romcević, Maja
AU  - Mitrić, Miodrag N.
AU  - Lazović, Vladimir
AU  - Dramlić, Dragan
AU  - Petricević, Slobodan
AU  - Romcević, Nebojsa
PY  - 2017
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/853
AB  - Bismuth germanium oxide Bi12GeO20 (BGO) has very interesting electrical, optical and magnetic properties. In order to make devices based on this material more flexible, its powder was used for preparing polymer composites. This study reports investigation of the effects of using different solvents and polymers in preparation of BGO composite on the microstructural and optical behaviour of the resulting material. Preparation of such composites by a solution casting method is described. Poly (methyl methacrylate) (PMMA) and polystyrene (PS)) were used as matrix materials and acetone and chloroform as solvents. Their microstructure and the quality of BGO dispersion and deaggregation in polymer matrix were analyzed by SEM, Raman, XRD and optical spectroscopy. The influence of particle size distribution, their shapes, and concentration on the optical transmission is calculated based on Mie scattering theory and discussed, too.
PB  - Elsevier Ltd
T2  - Journal of Alloys and Compounds
T1  - Preparation and characterization of bismuth germanium oxide (BGO) polymer composites
EP  - 849
SP  - 841
VL  - 695
DO  - 10.1016/j.jallcom.2016.10.140
ER  - 

@article{
author = "Brajović, Ljiljana and Stojanović, Dušica B. and Mihailović, Pedja and Marković, Smilja and Romcević, Maja and Mitrić, Miodrag N. and Lazović, Vladimir and Dramlić, Dragan and Petricević, Slobodan and Romcević, Nebojsa",
year = "2017",
abstract = "Bismuth germanium oxide Bi12GeO20 (BGO) has very interesting electrical, optical and magnetic properties. In order to make devices based on this material more flexible, its powder was used for preparing polymer composites. This study reports investigation of the effects of using different solvents and polymers in preparation of BGO composite on the microstructural and optical behaviour of the resulting material. Preparation of such composites by a solution casting method is described. Poly (methyl methacrylate) (PMMA) and polystyrene (PS)) were used as matrix materials and acetone and chloroform as solvents. Their microstructure and the quality of BGO dispersion and deaggregation in polymer matrix were analyzed by SEM, Raman, XRD and optical spectroscopy. The influence of particle size distribution, their shapes, and concentration on the optical transmission is calculated based on Mie scattering theory and discussed, too.",
publisher = "Elsevier Ltd",
journal = "Journal of Alloys and Compounds",
title = "Preparation and characterization of bismuth germanium oxide (BGO) polymer composites",
pages = "849-841",
volume = "695",
doi = "10.1016/j.jallcom.2016.10.140"
}

Brajović, L., Stojanović, D. B., Mihailović, P., Marković, S., Romcević, M., Mitrić, M. N., Lazović, V., Dramlić, D., Petricević, S.,& Romcević, N.. (2017). Preparation and characterization of bismuth germanium oxide (BGO) polymer composites. in Journal of Alloys and Compounds
Elsevier Ltd., 695, 841-849.
https://doi.org/10.1016/j.jallcom.2016.10.140

Brajović L, Stojanović DB, Mihailović P, Marković S, Romcević M, Mitrić MN, Lazović V, Dramlić D, Petricević S, Romcević N. Preparation and characterization of bismuth germanium oxide (BGO) polymer composites. in Journal of Alloys and Compounds. 2017;695:841-849.
doi:10.1016/j.jallcom.2016.10.140 .

Brajović, Ljiljana, Stojanović, Dušica B., Mihailović, Pedja, Marković, Smilja, Romcević, Maja, Mitrić, Miodrag N., Lazović, Vladimir, Dramlić, Dragan, Petricević, Slobodan, Romcević, Nebojsa, "Preparation and characterization of bismuth germanium oxide (BGO) polymer composites" in Journal of Alloys and Compounds, 695 (2017):841-849,
https://doi.org/10.1016/j.jallcom.2016.10.140 . .

TY  - JOUR
AU  - Dolić, Maja B.
AU  - Rajaković-Ognjanović, Vladana
AU  - Marković, Jelena P.
AU  - Jankovic-Mandić, Ljiljana J.
AU  - Mitrić, Miodrag N.
AU  - Onjia, Antonije
AU  - Rajaković, Ljubinka V.
PY  - 2015
UR  - https://grafar.grf.bg.ac.rs/handle/123456789/705
AB  - Natural minerals, such as quartz, clinoptilolite and calcite, are useful as sorbents for various applications, but their content of heavy metals ions is the most problematic obstacle to their application. Before their (re)use, the minerals must be purified. In this work, the subject was desorption of lead from a natural multi-component mineral sample consisting of a mixture of silicates (mainly quartz and clinoptilolite) and calcite formations. Besides deionized water, different extraction solutions were tested: NaCl, KCl, CaCl2, MgCl2, HCl, HNO3, EDTA, EDTA/HCl, EDTA/NaOAc-HOAc, HOAc, NaOAc and NaOAc-HOAc. Several parameters were varied in order to obtain the optimal conditions for the desorption process: the concentration of the extraction solution, the ratio of the mass of the sample and volume of the extractant, and the pH value of the suspension. The best purification effect in one desorption cycle was obtained when 0.1 M EDTA, at a pH value of 3.5 (0.2 M EDTA was mixed with 0.01 M acetic buffer, at pH value 3.0, in ratio 1:1) was applied. Sequential extraction (5 consecutive iterations) was performed to provide a more efficient purification process. The lead content (58.20 mg/kg) was decreased by: 20% (using HOAc), 21% (using EDTA) and by more than 50% (using EDTA/NaOAc-HOAc). The pH value and conductivity were measured at all critical points to clarify the mechanism of the desorption process. The formation of Pb-EDTA complex is the result of two parallel phenomena, complexing and ion-exchange. An enhanced adsorption capacity and an improved microelement profile for the purified samples were also attained. The mineralogical and radiochemical performances of the sample were determined by the X-ray diffraction and gamma spectrometry techniques. Microelement analyses of the native and purified samples were performed by inductively coupled plasma optical emission spectroscopy (ICP-OES).
PB  - Elsevier B.V.
T2  - Applied Surface Science
T1  - The effect of different extractants on lead desorption from a natural mineral
EP  - 231
SP  - 221
VL  - 324
DO  - 10.1016/j.apsusc.2014.10.112
ER  - 

@article{
author = "Dolić, Maja B. and Rajaković-Ognjanović, Vladana and Marković, Jelena P. and Jankovic-Mandić, Ljiljana J. and Mitrić, Miodrag N. and Onjia, Antonije and Rajaković, Ljubinka V.",
year = "2015",
abstract = "Natural minerals, such as quartz, clinoptilolite and calcite, are useful as sorbents for various applications, but their content of heavy metals ions is the most problematic obstacle to their application. Before their (re)use, the minerals must be purified. In this work, the subject was desorption of lead from a natural multi-component mineral sample consisting of a mixture of silicates (mainly quartz and clinoptilolite) and calcite formations. Besides deionized water, different extraction solutions were tested: NaCl, KCl, CaCl2, MgCl2, HCl, HNO3, EDTA, EDTA/HCl, EDTA/NaOAc-HOAc, HOAc, NaOAc and NaOAc-HOAc. Several parameters were varied in order to obtain the optimal conditions for the desorption process: the concentration of the extraction solution, the ratio of the mass of the sample and volume of the extractant, and the pH value of the suspension. The best purification effect in one desorption cycle was obtained when 0.1 M EDTA, at a pH value of 3.5 (0.2 M EDTA was mixed with 0.01 M acetic buffer, at pH value 3.0, in ratio 1:1) was applied. Sequential extraction (5 consecutive iterations) was performed to provide a more efficient purification process. The lead content (58.20 mg/kg) was decreased by: 20% (using HOAc), 21% (using EDTA) and by more than 50% (using EDTA/NaOAc-HOAc). The pH value and conductivity were measured at all critical points to clarify the mechanism of the desorption process. The formation of Pb-EDTA complex is the result of two parallel phenomena, complexing and ion-exchange. An enhanced adsorption capacity and an improved microelement profile for the purified samples were also attained. The mineralogical and radiochemical performances of the sample were determined by the X-ray diffraction and gamma spectrometry techniques. Microelement analyses of the native and purified samples were performed by inductively coupled plasma optical emission spectroscopy (ICP-OES).",
publisher = "Elsevier B.V.",
journal = "Applied Surface Science",
title = "The effect of different extractants on lead desorption from a natural mineral",
pages = "231-221",
volume = "324",
doi = "10.1016/j.apsusc.2014.10.112"
}

Dolić, M. B., Rajaković-Ognjanović, V., Marković, J. P., Jankovic-Mandić, L. J., Mitrić, M. N., Onjia, A.,& Rajaković, L. V.. (2015). The effect of different extractants on lead desorption from a natural mineral. in Applied Surface Science
Elsevier B.V.., 324, 221-231.
https://doi.org/10.1016/j.apsusc.2014.10.112

Dolić MB, Rajaković-Ognjanović V, Marković JP, Jankovic-Mandić LJ, Mitrić MN, Onjia A, Rajaković LV. The effect of different extractants on lead desorption from a natural mineral. in Applied Surface Science. 2015;324:221-231.
doi:10.1016/j.apsusc.2014.10.112 .

Dolić, Maja B., Rajaković-Ognjanović, Vladana, Marković, Jelena P., Jankovic-Mandić, Ljiljana J., Mitrić, Miodrag N., Onjia, Antonije, Rajaković, Ljubinka V., "The effect of different extractants on lead desorption from a natural mineral" in Applied Surface Science, 324 (2015):221-231,
https://doi.org/10.1016/j.apsusc.2014.10.112 . .