TY  - JOUR
AU  - Đolić, Maja B.
AU  - Rajaković-Ognjanović, Vladana N.
AU  - Štrbac, Svetlana
AU  - Dimitrijević, Suzana I.
AU  - Mitrić, Miodrag
AU  - Onjia, Antonije E.
AU  - Rajaković, Ljubinka V.
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1728
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. (C) 2017 Elsevier B. V. All rights reserved.
T2  - New Biotechnology
T1  - Natural sorbents modified by divalent Cu2+- and Zn2+- ions and their corresponding antimicrobial activity
VL  - 39
SP  - 150
EP  - 159
DO  - 10.1016/j.nbt.2017.03.001
ER  - 

@article{
author = "Đolić, Maja B. and Rajaković-Ognjanović, Vladana N. and Štrbac, Svetlana and Dimitrijević, Suzana I. and Mitrić, Miodrag and Onjia, Antonije E. 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. (C) 2017 Elsevier B. V. All rights reserved.",
journal = "New Biotechnology",
title = "Natural sorbents modified by divalent Cu2+- and Zn2+- ions and their corresponding antimicrobial activity",
volume = "39",
pages = "150-159",
doi = "10.1016/j.nbt.2017.03.001"
}

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

Đolić MB, Rajaković-Ognjanović VN, Štrbac S, Dimitrijević SI, Mitrić M, Onjia AE, 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 .

Đolić, Maja B., Rajaković-Ognjanović, Vladana N., Štrbac, Svetlana, Dimitrijević, Suzana I., Mitrić, Miodrag, Onjia, Antonije E., 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  - Todorović, Žaklina
AU  - Rajaković, Ljubinka V.
AU  - Onjia, Antonije E.
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1472
AB  - The two retention models, the linear solvent strength model (LSS) and the quadratic relationship, in addition to artificial neural network (ANN) approach, were compared in their ability to predict the retention behaviour of common cations (Li, Na, NH4, K, Mg and Ca) in isocratic ion chromatography using the methanesulfonic acid (MSA) eluent. Over wide variations in the MSA concentration, the quadratic model shows a quite good prediction power. LSS can be used only for monovalent cations and in the proximity of the experimental design point. ANN fails to predict the retention for the data not included in the training set. To find the optimal conditions in the experimental design, the normalized resolution product as a chromatographic objective function was employed. The optimum MSA concentration in the eluent on a Dionex CS12 column was found to be 18 mM, with the total analysis time of less than 10 min.
T2  - Hemijska industrija
T1  - Modelling of cations retention in ion chromatography with methanesulfonic acid as eluent
VL  - 71
IS  - 1
SP  - 27
EP  - 33
DO  - 10.2298/HEMIND151107014T
ER  - 

@article{
author = "Todorović, Žaklina and Rajaković, Ljubinka V. and Onjia, Antonije E.",
year = "2017",
abstract = "The two retention models, the linear solvent strength model (LSS) and the quadratic relationship, in addition to artificial neural network (ANN) approach, were compared in their ability to predict the retention behaviour of common cations (Li, Na, NH4, K, Mg and Ca) in isocratic ion chromatography using the methanesulfonic acid (MSA) eluent. Over wide variations in the MSA concentration, the quadratic model shows a quite good prediction power. LSS can be used only for monovalent cations and in the proximity of the experimental design point. ANN fails to predict the retention for the data not included in the training set. To find the optimal conditions in the experimental design, the normalized resolution product as a chromatographic objective function was employed. The optimum MSA concentration in the eluent on a Dionex CS12 column was found to be 18 mM, with the total analysis time of less than 10 min.",
journal = "Hemijska industrija",
title = "Modelling of cations retention in ion chromatography with methanesulfonic acid as eluent",
volume = "71",
number = "1",
pages = "27-33",
doi = "10.2298/HEMIND151107014T"
}

Todorović, Ž., Rajaković, L. V.,& Onjia, A. E.. (2017). Modelling of cations retention in ion chromatography with methanesulfonic acid as eluent. in Hemijska industrija, 71(1), 27-33.
https://doi.org/10.2298/HEMIND151107014T

Todorović Ž, Rajaković LV, Onjia AE. Modelling of cations retention in ion chromatography with methanesulfonic acid as eluent. in Hemijska industrija. 2017;71(1):27-33.
doi:10.2298/HEMIND151107014T .

Todorović, Žaklina, Rajaković, Ljubinka V., Onjia, Antonije E., "Modelling of cations retention in ion chromatography with methanesulfonic acid as eluent" in Hemijska industrija, 71, no. 1 (2017):27-33,
https://doi.org/10.2298/HEMIND151107014T . .

TY  - JOUR
AU  - Todorović, Žaklina
AU  - Rajaković, Ljubinka V.
AU  - Onjia, Antonije E.
PY  - 2016
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1188
AB  - Interpretive retention modeling was utilized to optimize the isocratic ion chromatographic (IC) separation of the nine anions (formate, fluoride, chloride, nitrite, bromide, nitrate, phosphate, sulfate and oxalate). The carbonate-bicarbonate eluent was used and separation was done on a Dionex AS14 ion-exchange column. The influence of combined effects of two mobile phase factors, the total eluent concentration (2-6 mM) and the carbonate/bicaronate ratio from 1:9 to 9:1 (which correspond to pH range 9.35-11.27), on the IC separation was studied. The multiple species analyte/eluent model that takes into account ion-exchange equilibria of the eluent and sample anions was used. In order to estimate the parameters in the model, a non-linear fitting of the retention data, obtained at two-factor three-level experimental design, was applied. To find the optimal conditions in the experimental design, the normalized resolution product as a chromatographic objective function was employed. This criterion includes both the individual peak resolution and the total analysis time. A good agreement between experimental and simulated chromatograms was obtained.
T2  - Journal of the Serbian Chemical Society
T1  - Interpretative optimization of the isocratic ion chromatographic separation of anions
VL  - 81
IS  - 6
SP  - 661
EP  - 672
DO  - 10.2298/JSC150927022T
ER  - 

@article{
author = "Todorović, Žaklina and Rajaković, Ljubinka V. and Onjia, Antonije E.",
year = "2016",
abstract = "Interpretive retention modeling was utilized to optimize the isocratic ion chromatographic (IC) separation of the nine anions (formate, fluoride, chloride, nitrite, bromide, nitrate, phosphate, sulfate and oxalate). The carbonate-bicarbonate eluent was used and separation was done on a Dionex AS14 ion-exchange column. The influence of combined effects of two mobile phase factors, the total eluent concentration (2-6 mM) and the carbonate/bicaronate ratio from 1:9 to 9:1 (which correspond to pH range 9.35-11.27), on the IC separation was studied. The multiple species analyte/eluent model that takes into account ion-exchange equilibria of the eluent and sample anions was used. In order to estimate the parameters in the model, a non-linear fitting of the retention data, obtained at two-factor three-level experimental design, was applied. To find the optimal conditions in the experimental design, the normalized resolution product as a chromatographic objective function was employed. This criterion includes both the individual peak resolution and the total analysis time. A good agreement between experimental and simulated chromatograms was obtained.",
journal = "Journal of the Serbian Chemical Society",
title = "Interpretative optimization of the isocratic ion chromatographic separation of anions",
volume = "81",
number = "6",
pages = "661-672",
doi = "10.2298/JSC150927022T"
}

Todorović, Ž., Rajaković, L. V.,& Onjia, A. E.. (2016). Interpretative optimization of the isocratic ion chromatographic separation of anions. in Journal of the Serbian Chemical Society, 81(6), 661-672.
https://doi.org/10.2298/JSC150927022T

Todorović Ž, Rajaković LV, Onjia AE. Interpretative optimization of the isocratic ion chromatographic separation of anions. in Journal of the Serbian Chemical Society. 2016;81(6):661-672.
doi:10.2298/JSC150927022T .

Todorović, Žaklina, Rajaković, Ljubinka V., Onjia, Antonije E., "Interpretative optimization of the isocratic ion chromatographic separation of anions" in Journal of the Serbian Chemical Society, 81, no. 6 (2016):661-672,
https://doi.org/10.2298/JSC150927022T . .

TY  - JOUR
AU  - Đolić, Maja B.
AU  - Rajaković-Ognjanović, Vladana N.
AU  - Marković, Jelena P.
AU  - Janković Mandić, Ljiljana
AU  - Mitrić, Miodrag
AU  - Onjia, Antonije E.
AU  - Rajaković, Ljubinka V.
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/282
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). (C) 2014 Elsevier B.V. All rights reserved.
T2  - Applied Surface Science
T1  - The effect of different extractants on lead desorption from a natural mineral
VL  - 324
SP  - 221
EP  - 231
DO  - 10.1016/j.apsusc.2014.10.112
ER  - 

@article{
author = "Đolić, Maja B. and Rajaković-Ognjanović, Vladana N. and Marković, Jelena P. and Janković Mandić, Ljiljana and Mitrić, Miodrag and Onjia, Antonije E. 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). (C) 2014 Elsevier B.V. All rights reserved.",
journal = "Applied Surface Science",
title = "The effect of different extractants on lead desorption from a natural mineral",
volume = "324",
pages = "221-231",
doi = "10.1016/j.apsusc.2014.10.112"
}

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

Đolić MB, Rajaković-Ognjanović VN, Marković JP, Janković Mandić L, Mitrić M, Onjia AE, 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 .

Đolić, Maja B., Rajaković-Ognjanović, Vladana N., Marković, Jelena P., Janković Mandić, Ljiljana, Mitrić, Miodrag, Onjia, Antonije E., 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 . .

TY  - JOUR
AU  - Ignjatović, Ivana D. Sredović
AU  - Onjia, Antonije E.
AU  - Ignjatović, Ljubiša M.
AU  - Todorović, Žaklina
AU  - Rajaković, Ljubinka V.
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/713
AB  - Determination of total halogens in coal was investigated with oxygen bomb combustion followed by ion chromatography. Experimental parameters were optimized by fractional factorial design and response surface methodology. Fractional factorial design was employed in screening experiments to evaluate the influence of the oxygen pressure, catalyst, absorption solution, reduction reagent, bomb cooling time, and a combustion aid on the combustion of coal in an oxygen bomb. Response surface methodology was conducted to further refine the results obtained by fractional factorial design and to define parameters for the procedure. The accuracy and precision of combustion with ion chromatography were evaluated by the use of two certified reference materials and by fortified in-house coal standards. The limits of detection and quantification for total halogens were 0.84 and 2.80 milligrams per kilogram, respectively, for 500 milligram samples. Ion chromatography provided relative standard deviations less than 4 percent, recoveries exceeding 95 percent, and was convenient. This method is recommended for routine determination of total halogens in coal because of its reliability.
T2  - Analytical Letters
T1  - Experimental Design Optimization of the Determination of Total Halogens in Coal by Combustion-Ion Chromatography
VL  - 48
IS  - 16
SP  - 2597
EP  - 2612
DO  - 10.1080/00032719.2015.1041029
ER  - 

@article{
author = "Ignjatović, Ivana D. Sredović and Onjia, Antonije E. and Ignjatović, Ljubiša M. and Todorović, Žaklina and Rajaković, Ljubinka V.",
year = "2015",
abstract = "Determination of total halogens in coal was investigated with oxygen bomb combustion followed by ion chromatography. Experimental parameters were optimized by fractional factorial design and response surface methodology. Fractional factorial design was employed in screening experiments to evaluate the influence of the oxygen pressure, catalyst, absorption solution, reduction reagent, bomb cooling time, and a combustion aid on the combustion of coal in an oxygen bomb. Response surface methodology was conducted to further refine the results obtained by fractional factorial design and to define parameters for the procedure. The accuracy and precision of combustion with ion chromatography were evaluated by the use of two certified reference materials and by fortified in-house coal standards. The limits of detection and quantification for total halogens were 0.84 and 2.80 milligrams per kilogram, respectively, for 500 milligram samples. Ion chromatography provided relative standard deviations less than 4 percent, recoveries exceeding 95 percent, and was convenient. This method is recommended for routine determination of total halogens in coal because of its reliability.",
journal = "Analytical Letters",
title = "Experimental Design Optimization of the Determination of Total Halogens in Coal by Combustion-Ion Chromatography",
volume = "48",
number = "16",
pages = "2597-2612",
doi = "10.1080/00032719.2015.1041029"
}

Ignjatović, I. D. S., Onjia, A. E., Ignjatović, L. M., Todorović, Ž.,& Rajaković, L. V.. (2015). Experimental Design Optimization of the Determination of Total Halogens in Coal by Combustion-Ion Chromatography. in Analytical Letters, 48(16), 2597-2612.
https://doi.org/10.1080/00032719.2015.1041029

Ignjatović IDS, Onjia AE, Ignjatović LM, Todorović Ž, Rajaković LV. Experimental Design Optimization of the Determination of Total Halogens in Coal by Combustion-Ion Chromatography. in Analytical Letters. 2015;48(16):2597-2612.
doi:10.1080/00032719.2015.1041029 .

Ignjatović, Ivana D. Sredović, Onjia, Antonije E., Ignjatović, Ljubiša M., Todorović, Žaklina, Rajaković, Ljubinka V., "Experimental Design Optimization of the Determination of Total Halogens in Coal by Combustion-Ion Chromatography" in Analytical Letters, 48, no. 16 (2015):2597-2612,
https://doi.org/10.1080/00032719.2015.1041029 . .

TY  - JOUR
AU  - Đolić, Maja B.
AU  - Rajaković-Ognjanović, Vladana N.
AU  - Štrbac, Svetlana
AU  - Rakočević, Zlatko Lj.
AU  - Veljović, Đorđe N.
AU  - Dimitrijević, Suzana I.
AU  - Rajaković, Ljubinka V.
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/849
AB  - This study is focused on the surface modifications of the materials that are used for antimicrobial water treatment. Sorbents of different origin were activated by Ag+-ions. The selection of the most appropriate materials and the most effective activation agents was done according to the results of the sorption and desorption kinetic studies. Sorption capacities of selected sorbents: granulated activated carbon (GAC), zeolite (Z), and titanium dioxide (T), activated by Ag+-ions were following: 42.06, 13.51 and 17.53 mg/g, respectively. The antimicrobial activity of Ag/Z, Ag/GAC and Ag/T sorbents were tested against Gram-negative bacteria E. coli, Gram-positive bacteria S. aureus and yeast C. albicans. After 15 min of exposure period, the highest cell removal was obtained using Ag/Z against S. aureus and E. coli, 98.8 and 93.5%, respectively. Yeast cell inactivation was unsatisfactory for all three activated sorbents. The antimicrobial pathway of the activated sorbents has been examined by two separate tests - Ag+-ions desorbed from the activated surface to the aqueous phase and microbial cell removal caused by the Ag+-ions from the solid phase (activated surface sites). The results indicated that disinfection process significantly depended on the microbial-activated sites interactions on the modified surface. The chemical state of the activating agent had crucial impact to the inhibition rate. The characterization of the native and modified sorbents was performed by X-ray diffraction technique, X-ray photoelectron spectroscopy and scanning electron microscope. The concentration of adsorbed and released ions was determined by inductively coupled plasma optical emission spectroscopy and mass spectrometry. The antimicrobial efficiency of activated sorbents was related not only to the concentration of the activating agent, but moreover on the surface characteristics of the material, which affects the distribution and the accessibility of the activating agent. (C) 2015 Elsevier B.V. All rights reserved.
PB  - Elsevier
T2  - Applied Surface Science
T1  - The antimicrobial efficiency of silver activated sorbents
VL  - 357
SP  - 819
EP  - 831
DO  - 10.1016/j.apsusc.2015.09.032
ER  - 

@article{
author = "Đolić, Maja B. and Rajaković-Ognjanović, Vladana N. and Štrbac, Svetlana and Rakočević, Zlatko Lj. and Veljović, Đorđe N. and Dimitrijević, Suzana I. and Rajaković, Ljubinka V.",
year = "2015",
abstract = "This study is focused on the surface modifications of the materials that are used for antimicrobial water treatment. Sorbents of different origin were activated by Ag+-ions. The selection of the most appropriate materials and the most effective activation agents was done according to the results of the sorption and desorption kinetic studies. Sorption capacities of selected sorbents: granulated activated carbon (GAC), zeolite (Z), and titanium dioxide (T), activated by Ag+-ions were following: 42.06, 13.51 and 17.53 mg/g, respectively. The antimicrobial activity of Ag/Z, Ag/GAC and Ag/T sorbents were tested against Gram-negative bacteria E. coli, Gram-positive bacteria S. aureus and yeast C. albicans. After 15 min of exposure period, the highest cell removal was obtained using Ag/Z against S. aureus and E. coli, 98.8 and 93.5%, respectively. Yeast cell inactivation was unsatisfactory for all three activated sorbents. The antimicrobial pathway of the activated sorbents has been examined by two separate tests - Ag+-ions desorbed from the activated surface to the aqueous phase and microbial cell removal caused by the Ag+-ions from the solid phase (activated surface sites). The results indicated that disinfection process significantly depended on the microbial-activated sites interactions on the modified surface. The chemical state of the activating agent had crucial impact to the inhibition rate. The characterization of the native and modified sorbents was performed by X-ray diffraction technique, X-ray photoelectron spectroscopy and scanning electron microscope. The concentration of adsorbed and released ions was determined by inductively coupled plasma optical emission spectroscopy and mass spectrometry. The antimicrobial efficiency of activated sorbents was related not only to the concentration of the activating agent, but moreover on the surface characteristics of the material, which affects the distribution and the accessibility of the activating agent. (C) 2015 Elsevier B.V. All rights reserved.",
publisher = "Elsevier",
journal = "Applied Surface Science",
title = "The antimicrobial efficiency of silver activated sorbents",
volume = "357",
pages = "819-831",
doi = "10.1016/j.apsusc.2015.09.032"
}

Đolić, M. B., Rajaković-Ognjanović, V. N., Štrbac, S., Rakočević, Z. Lj., Veljović, Đ. N., Dimitrijević, S. I.,& Rajaković, L. V.. (2015). The antimicrobial efficiency of silver activated sorbents. in Applied Surface Science
Elsevier., 357, 819-831.
https://doi.org/10.1016/j.apsusc.2015.09.032

Đolić MB, Rajaković-Ognjanović VN, Štrbac S, Rakočević ZL, Veljović ĐN, Dimitrijević SI, Rajaković LV. The antimicrobial efficiency of silver activated sorbents. in Applied Surface Science. 2015;357:819-831.
doi:10.1016/j.apsusc.2015.09.032 .

Đolić, Maja B., Rajaković-Ognjanović, Vladana N., Štrbac, Svetlana, Rakočević, Zlatko Lj., Veljović, Đorđe N., Dimitrijević, Suzana I., Rajaković, Ljubinka V., "The antimicrobial efficiency of silver activated sorbents" in Applied Surface Science, 357 (2015):819-831,
https://doi.org/10.1016/j.apsusc.2015.09.032 . .

TY  - JOUR
AU  - Markovic, Dana D.
AU  - Lekić, Branislava M.
AU  - Rajaković-Ognjanović, Vladana N.
AU  - Onjia, Antonije E.
AU  - Rajaković, Ljubinka V.
PY  - 2014
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/5871
AB  - Numerous regression approaches to isotherm parameters estimation appear in the literature. The real insight into the proper modeling pattern can be achieved only by testing methods on a very big number of cases. Experimentally, it cannot be done in a reasonable time, so the Monte Carlo simulation method was applied. The objective of this paper is to introduce and compare numerical approaches that involve different levels of knowledge about the noise structure of the analytical method used for initial and equilibrium concentration determination. Six levels of homoscedastic noise and five types of heteroscedastic noise precision models were considered. Performance of the methods was statistically evaluated based on median percentage error and mean absolute relative error in parameter estimates. The present study showed a clear distinction between two cases. When equilibrium experiments are performed only once, for the homoscedastic case, the winning error function is ordinary least squares, while for the case of heteroscedastic noise the use of orthogonal distance regression or Margarts percent standard deviation is suggested. It was found that in case when experiments are repeated three times the simple method of weighted least squares performed as well as more complicated orthogonal distance regression method.
T2  - Scientific World Journal
T1  - A New Approach in Regression Analysis for Modeling Adsorption Isotherms
DO  - 10.1155/2014/930879
ER  - 

@article{
author = "Markovic, Dana D. and Lekić, Branislava M. and Rajaković-Ognjanović, Vladana N. and Onjia, Antonije E. and Rajaković, Ljubinka V.",
year = "2014",
abstract = "Numerous regression approaches to isotherm parameters estimation appear in the literature. The real insight into the proper modeling pattern can be achieved only by testing methods on a very big number of cases. Experimentally, it cannot be done in a reasonable time, so the Monte Carlo simulation method was applied. The objective of this paper is to introduce and compare numerical approaches that involve different levels of knowledge about the noise structure of the analytical method used for initial and equilibrium concentration determination. Six levels of homoscedastic noise and five types of heteroscedastic noise precision models were considered. Performance of the methods was statistically evaluated based on median percentage error and mean absolute relative error in parameter estimates. The present study showed a clear distinction between two cases. When equilibrium experiments are performed only once, for the homoscedastic case, the winning error function is ordinary least squares, while for the case of heteroscedastic noise the use of orthogonal distance regression or Margarts percent standard deviation is suggested. It was found that in case when experiments are repeated three times the simple method of weighted least squares performed as well as more complicated orthogonal distance regression method.",
journal = "Scientific World Journal",
title = "A New Approach in Regression Analysis for Modeling Adsorption Isotherms",
doi = "10.1155/2014/930879"
}

Markovic, D. D., Lekić, B. M., Rajaković-Ognjanović, V. N., Onjia, A. E.,& Rajaković, L. V.. (2014). A New Approach in Regression Analysis for Modeling Adsorption Isotherms. in Scientific World Journal.
https://doi.org/10.1155/2014/930879

Markovic DD, Lekić BM, Rajaković-Ognjanović VN, Onjia AE, Rajaković LV. A New Approach in Regression Analysis for Modeling Adsorption Isotherms. in Scientific World Journal. 2014;.
doi:10.1155/2014/930879 .

Markovic, Dana D., Lekić, Branislava M., Rajaković-Ognjanović, Vladana N., Onjia, Antonije E., Rajaković, Ljubinka V., "A New Approach in Regression Analysis for Modeling Adsorption Isotherms" in Scientific World Journal (2014),
https://doi.org/10.1155/2014/930879 . .

TY  - JOUR
AU  - Lekić, Branislava M.
AU  - Markovic, Dana D.
AU  - Rajaković-Ognjanović, Vladana N.
AU  - Đukić, Aleksandar R.
AU  - Rajaković, Ljubinka V.
PY  - 2013
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/5698
AB  - In this study, removal of arsenic ions using two industrial by-products as adsorbents is represented. Removal of As(III) and As(V) from water was carried out with industrial by-products: residual from the groundwater treatment process, iron-manganese oxide coated sand (IMOCS), and blast furnace slag from steel production (BFS), both inexpensive and locally available. In addition, the BFS was modified in order to minimise its deteriorating impact on the initial water quality. Kinetic and equilibrium studies were carried out using batch and fixed-bed column adsorption techniques under the conditions that are likely to occur in real water treatment systems. To evaluate the application for real groundwater treatment, the capacities of the selected materials were further compared to those exhibited by commercial sorbents, which were examined under the same experimental conditions. IMOCS was found to be a good and inexpensive sorbent for arsenic, while BFS and modified slag showed the highest affinity towards arsenic. All examined waste materials exhibited better sorption performances for As(V). The maximum sorption capacity in the batch reactor was obtained for blast furnace slag, 4040 mu gAs(V)/g.
T2  - Journal of Chemistry
T1  - Arsenic Removal from Water Using Industrial By-Products
DO  - 10.1155/2013/121024
ER  - 

@article{
author = "Lekić, Branislava M. and Markovic, Dana D. and Rajaković-Ognjanović, Vladana N. and Đukić, Aleksandar R. and Rajaković, Ljubinka V.",
year = "2013",
abstract = "In this study, removal of arsenic ions using two industrial by-products as adsorbents is represented. Removal of As(III) and As(V) from water was carried out with industrial by-products: residual from the groundwater treatment process, iron-manganese oxide coated sand (IMOCS), and blast furnace slag from steel production (BFS), both inexpensive and locally available. In addition, the BFS was modified in order to minimise its deteriorating impact on the initial water quality. Kinetic and equilibrium studies were carried out using batch and fixed-bed column adsorption techniques under the conditions that are likely to occur in real water treatment systems. To evaluate the application for real groundwater treatment, the capacities of the selected materials were further compared to those exhibited by commercial sorbents, which were examined under the same experimental conditions. IMOCS was found to be a good and inexpensive sorbent for arsenic, while BFS and modified slag showed the highest affinity towards arsenic. All examined waste materials exhibited better sorption performances for As(V). The maximum sorption capacity in the batch reactor was obtained for blast furnace slag, 4040 mu gAs(V)/g.",
journal = "Journal of Chemistry",
title = "Arsenic Removal from Water Using Industrial By-Products",
doi = "10.1155/2013/121024"
}

Lekić, B. M., Markovic, D. D., Rajaković-Ognjanović, V. N., Đukić, A. R.,& Rajaković, L. V.. (2013). Arsenic Removal from Water Using Industrial By-Products. in Journal of Chemistry.
https://doi.org/10.1155/2013/121024

Lekić BM, Markovic DD, Rajaković-Ognjanović VN, Đukić AR, Rajaković LV. Arsenic Removal from Water Using Industrial By-Products. in Journal of Chemistry. 2013;.
doi:10.1155/2013/121024 .

Lekić, Branislava M., Markovic, Dana D., Rajaković-Ognjanović, Vladana N., Đukić, Aleksandar R., Rajaković, Ljubinka V., "Arsenic Removal from Water Using Industrial By-Products" in Journal of Chemistry (2013),
https://doi.org/10.1155/2013/121024 . .

TY  - JOUR
AU  - Rajaković, Ljubinka V.
AU  - Todorović, Žaklina
AU  - Rajaković-Ognjanović, Vladana N.
AU  - Onjia, Antonije E.
PY  - 2013
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/5759
AB  - Arsenic exists in the form of various chemical species differing in their physicochemical behaviour, toxicity, bioavailability and biotransformation. The determination of arsenic species is an important issue for environmental, clinical and food chemistry. However, differentiation of these species is a quite complex analytical task. Numerous speciation procedures have been studied that include electrochemical, chromatographic, spectrometric and hyphenated techniques. This review presents the relevant research in the field of arsenic speciation analysis with novel applications and significant advances. Stability of arsenic species and each of the analytical steps (sample collection, storage, preservation, extraction) of the arsenic speciation methods is particularly evaluated. Analytical validation and performance of these Methods are also reviewed.
T2  - Journal of the Serbian Chemical Society
T1  - Analytical methods for arsenic speciation analysis
VL  - 78
IS  - 10
SP  - 1461
EP  - 1479
DO  - 10.2298/JSC130315064R
ER  - 

@article{
author = "Rajaković, Ljubinka V. and Todorović, Žaklina and Rajaković-Ognjanović, Vladana N. and Onjia, Antonije E.",
year = "2013",
abstract = "Arsenic exists in the form of various chemical species differing in their physicochemical behaviour, toxicity, bioavailability and biotransformation. The determination of arsenic species is an important issue for environmental, clinical and food chemistry. However, differentiation of these species is a quite complex analytical task. Numerous speciation procedures have been studied that include electrochemical, chromatographic, spectrometric and hyphenated techniques. This review presents the relevant research in the field of arsenic speciation analysis with novel applications and significant advances. Stability of arsenic species and each of the analytical steps (sample collection, storage, preservation, extraction) of the arsenic speciation methods is particularly evaluated. Analytical validation and performance of these Methods are also reviewed.",
journal = "Journal of the Serbian Chemical Society",
title = "Analytical methods for arsenic speciation analysis",
volume = "78",
number = "10",
pages = "1461-1479",
doi = "10.2298/JSC130315064R"
}

Rajaković, L. V., Todorović, Ž., Rajaković-Ognjanović, V. N.,& Onjia, A. E.. (2013). Analytical methods for arsenic speciation analysis. in Journal of the Serbian Chemical Society, 78(10), 1461-1479.
https://doi.org/10.2298/JSC130315064R

Rajaković LV, Todorović Ž, Rajaković-Ognjanović VN, Onjia AE. Analytical methods for arsenic speciation analysis. in Journal of the Serbian Chemical Society. 2013;78(10):1461-1479.
doi:10.2298/JSC130315064R .

Rajaković, Ljubinka V., Todorović, Žaklina, Rajaković-Ognjanović, Vladana N., Onjia, Antonije E., "Analytical methods for arsenic speciation analysis" in Journal of the Serbian Chemical Society, 78, no. 10 (2013):1461-1479,
https://doi.org/10.2298/JSC130315064R . .

TY  - JOUR
AU  - Zivojinovic, Dragana Z.
AU  - Rajaković-Ognjanović, Vladana N.
AU  - Onjia, Antonije E.
AU  - Rajaković, Ljubinka V.
PY  - 2013
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/5568
AB  - In this study, a multivariate statistical approach was used to identify the key variables responsible for process water quality in a power plant. The ion species that could cause corrosion in one of the major thermal power plants (TPP) in Serbia were monitored. A suppressed ion chromatographic (IC) method for the determination of the target anions and cations at trace levels was applied. In addition, some metals important for corrosion, i.e., copper and iron, were also analysed by the graphite furnace atomic absorption spectrophotometric (GFAAS) method. The control parameters, i.e., pH, dissolved oxygen and silica, were measured on-line. The analysis of a series of representative samples from the TPP Nikola Tesla, collected in different plant operation modes, was performed. Every day laboratory and on-line analysis provides a large number of data in relation to the quality of water in the water-steam cycle (WSC) which should be evaluated and processed. The goal of this investigation was to apply multivariate statistical techniques and choose the most applicable technique for this case. Factor analysis (FA), especially principal component analysis (PCA) and cluster analysis (CA) were investigated. These methods were applied for the evaluation of the spatial/temporal variations of process water and for the estimation of 13 quality parameters which were monitored at 11 locations in the WSC in different working conditions during a twelve month period. It was concluded that PCA was the most useful method for identifying functional relations between the elements. After data reduction, four main factors controlling the variability were identified. Hierarchical cluster analysis (HCA) was applied for sample differentiation according to the sample location and working mode of the TPP. On the basis of this research, the new design of an optimal monitoring strategy for future analysis was proposed with a reduced number of measured parameters and with reduced frequency of their measurements.
T2  - Central European Journal of Chemistry
T1  - Spatial variations in the distribution of trace ionic impurities in the water-steam cycle in a thermal power plant based on a multivariate statistical approach
VL  - 11
IS  - 9
SP  - 1456
EP  - 1470
DO  - 10.2478/s11532-013-0286-4
ER  - 

@article{
author = "Zivojinovic, Dragana Z. and Rajaković-Ognjanović, Vladana N. and Onjia, Antonije E. and Rajaković, Ljubinka V.",
year = "2013",
abstract = "In this study, a multivariate statistical approach was used to identify the key variables responsible for process water quality in a power plant. The ion species that could cause corrosion in one of the major thermal power plants (TPP) in Serbia were monitored. A suppressed ion chromatographic (IC) method for the determination of the target anions and cations at trace levels was applied. In addition, some metals important for corrosion, i.e., copper and iron, were also analysed by the graphite furnace atomic absorption spectrophotometric (GFAAS) method. The control parameters, i.e., pH, dissolved oxygen and silica, were measured on-line. The analysis of a series of representative samples from the TPP Nikola Tesla, collected in different plant operation modes, was performed. Every day laboratory and on-line analysis provides a large number of data in relation to the quality of water in the water-steam cycle (WSC) which should be evaluated and processed. The goal of this investigation was to apply multivariate statistical techniques and choose the most applicable technique for this case. Factor analysis (FA), especially principal component analysis (PCA) and cluster analysis (CA) were investigated. These methods were applied for the evaluation of the spatial/temporal variations of process water and for the estimation of 13 quality parameters which were monitored at 11 locations in the WSC in different working conditions during a twelve month period. It was concluded that PCA was the most useful method for identifying functional relations between the elements. After data reduction, four main factors controlling the variability were identified. Hierarchical cluster analysis (HCA) was applied for sample differentiation according to the sample location and working mode of the TPP. On the basis of this research, the new design of an optimal monitoring strategy for future analysis was proposed with a reduced number of measured parameters and with reduced frequency of their measurements.",
journal = "Central European Journal of Chemistry",
title = "Spatial variations in the distribution of trace ionic impurities in the water-steam cycle in a thermal power plant based on a multivariate statistical approach",
volume = "11",
number = "9",
pages = "1456-1470",
doi = "10.2478/s11532-013-0286-4"
}

Zivojinovic, D. Z., Rajaković-Ognjanović, V. N., Onjia, A. E.,& Rajaković, L. V.. (2013). Spatial variations in the distribution of trace ionic impurities in the water-steam cycle in a thermal power plant based on a multivariate statistical approach. in Central European Journal of Chemistry, 11(9), 1456-1470.
https://doi.org/10.2478/s11532-013-0286-4

Zivojinovic DZ, Rajaković-Ognjanović VN, Onjia AE, Rajaković LV. Spatial variations in the distribution of trace ionic impurities in the water-steam cycle in a thermal power plant based on a multivariate statistical approach. in Central European Journal of Chemistry. 2013;11(9):1456-1470.
doi:10.2478/s11532-013-0286-4 .

Zivojinovic, Dragana Z., Rajaković-Ognjanović, Vladana N., Onjia, Antonije E., Rajaković, Ljubinka V., "Spatial variations in the distribution of trace ionic impurities in the water-steam cycle in a thermal power plant based on a multivariate statistical approach" in Central European Journal of Chemistry, 11, no. 9 (2013):1456-1470,
https://doi.org/10.2478/s11532-013-0286-4 . .

TY  - JOUR
AU  - Rajaković, Ljubinka V.
AU  - Markovic, Dana D.
AU  - Rajaković-Ognjanović, Vladana N.
AU  - Antanasijević, Davor Z.
PY  - 2012
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/5225
AB  - The analytical properties of an analytical method must be evaluated through validation protocols. Beside specificity and/or selectivity, linearity of calibration, repeatability and accuracy, the most important parameters are: LOD (limit of detection) and LOQ (limit of quantification). Through these limits, it is possible to define the smallest concentration of analyte that can be reliably detected and quantified. To establish these limits, an analyst should apply several estimation methods and test a large number of sample replicates. It is difficult to make a compromise between complex statistical programs and the simple analytical demand to have reliable analytical parameters. The differences and equivalency of estimation methods and approaches for analytical limits could be overcome by an experimental comparison. In this paper, the focus is the LOD of inductively coupled plasma-mass spectrometry (ICP-MS) measurements employed for the determination of arsenic. The current approaches for the calculation of the LOD are summarized and critically discussed. (C) 2012 Elsevier B.V. All rights reserved.
T2  - Talanta
T1  - Review: The approaches for estimation of limit of detection for ICP-MS trace analysis of arsenic
VL  - 102
IS  - SI
SP  - 79
EP  - 87
DO  - 10.1016/j.talanta.2012.08.016
ER  - 

@article{
author = "Rajaković, Ljubinka V. and Markovic, Dana D. and Rajaković-Ognjanović, Vladana N. and Antanasijević, Davor Z.",
year = "2012",
abstract = "The analytical properties of an analytical method must be evaluated through validation protocols. Beside specificity and/or selectivity, linearity of calibration, repeatability and accuracy, the most important parameters are: LOD (limit of detection) and LOQ (limit of quantification). Through these limits, it is possible to define the smallest concentration of analyte that can be reliably detected and quantified. To establish these limits, an analyst should apply several estimation methods and test a large number of sample replicates. It is difficult to make a compromise between complex statistical programs and the simple analytical demand to have reliable analytical parameters. The differences and equivalency of estimation methods and approaches for analytical limits could be overcome by an experimental comparison. In this paper, the focus is the LOD of inductively coupled plasma-mass spectrometry (ICP-MS) measurements employed for the determination of arsenic. The current approaches for the calculation of the LOD are summarized and critically discussed. (C) 2012 Elsevier B.V. All rights reserved.",
journal = "Talanta",
title = "Review: The approaches for estimation of limit of detection for ICP-MS trace analysis of arsenic",
volume = "102",
number = "SI",
pages = "79-87",
doi = "10.1016/j.talanta.2012.08.016"
}

Rajaković, L. V., Markovic, D. D., Rajaković-Ognjanović, V. N.,& Antanasijević, D. Z.. (2012). Review: The approaches for estimation of limit of detection for ICP-MS trace analysis of arsenic. in Talanta, 102(SI), 79-87.
https://doi.org/10.1016/j.talanta.2012.08.016

Rajaković LV, Markovic DD, Rajaković-Ognjanović VN, Antanasijević DZ. Review: The approaches for estimation of limit of detection for ICP-MS trace analysis of arsenic. in Talanta. 2012;102(SI):79-87.
doi:10.1016/j.talanta.2012.08.016 .

Rajaković, Ljubinka V., Markovic, Dana D., Rajaković-Ognjanović, Vladana N., Antanasijević, Davor Z., "Review: The approaches for estimation of limit of detection for ICP-MS trace analysis of arsenic" in Talanta, 102, no. SI (2012):79-87,
https://doi.org/10.1016/j.talanta.2012.08.016 . .

TY  - JOUR
AU  - Zarkovic, Darja B.
AU  - Todorović, Žaklina
AU  - Rajaković, Ljubinka V.
PY  - 2011
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/4245
AB  - In this study, the performance and the efficiency of physico-chemical effluent treatment in a paper mill was investigated, with the aim of evaluating the treatment rationality and running stability. The effluent treatment plant (ETP) uses alum as a coagulant and polyacrylamide as a flocculant in multi-stage water purification. Inadequate efficiency and some operational problems were observed and their occurrences were investigated. Several simple measures inside the mill and some technical measures can prevent or postpone expensive end-of-pipe treatment investments, such as biological treatment. Chemically enhanced primary treatment under optimal operating conditions can be a stand-alone technique for achieving high quality effluent. Furthermore, reductions in wastewater generation in combination with fiber and filler recovery provide environmental benefits as well as significant economic savings in production. The advantages of the cleaner production approach in existing treatment units compared to expensive biological end-of-pipe technologies are obvious. This study demonstrated that the examined mill could easily and cost-effectively change its water system toward strict discharge limits by continuing to use the existing treatment units. (C) 2010 Elsevier Ltd. All rights reserved.
T2  - Journal of Cleaner Production
T1  - Simple and cost-effective measures for the improvement of paper mill effluent treatment - A case study
VL  - 19
IS  - 6-7
SP  - 764
EP  - 774
DO  - 10.1016/j.jclepro.2010.11.015
ER  - 

@article{
author = "Zarkovic, Darja B. and Todorović, Žaklina and Rajaković, Ljubinka V.",
year = "2011",
abstract = "In this study, the performance and the efficiency of physico-chemical effluent treatment in a paper mill was investigated, with the aim of evaluating the treatment rationality and running stability. The effluent treatment plant (ETP) uses alum as a coagulant and polyacrylamide as a flocculant in multi-stage water purification. Inadequate efficiency and some operational problems were observed and their occurrences were investigated. Several simple measures inside the mill and some technical measures can prevent or postpone expensive end-of-pipe treatment investments, such as biological treatment. Chemically enhanced primary treatment under optimal operating conditions can be a stand-alone technique for achieving high quality effluent. Furthermore, reductions in wastewater generation in combination with fiber and filler recovery provide environmental benefits as well as significant economic savings in production. The advantages of the cleaner production approach in existing treatment units compared to expensive biological end-of-pipe technologies are obvious. This study demonstrated that the examined mill could easily and cost-effectively change its water system toward strict discharge limits by continuing to use the existing treatment units. (C) 2010 Elsevier Ltd. All rights reserved.",
journal = "Journal of Cleaner Production",
title = "Simple and cost-effective measures for the improvement of paper mill effluent treatment - A case study",
volume = "19",
number = "6-7",
pages = "764-774",
doi = "10.1016/j.jclepro.2010.11.015"
}

Zarkovic, D. B., Todorović, Ž.,& Rajaković, L. V.. (2011). Simple and cost-effective measures for the improvement of paper mill effluent treatment - A case study. in Journal of Cleaner Production, 19(6-7), 764-774.
https://doi.org/10.1016/j.jclepro.2010.11.015

Zarkovic DB, Todorović Ž, Rajaković LV. Simple and cost-effective measures for the improvement of paper mill effluent treatment - A case study. in Journal of Cleaner Production. 2011;19(6-7):764-774.
doi:10.1016/j.jclepro.2010.11.015 .

Zarkovic, Darja B., Todorović, Žaklina, Rajaković, Ljubinka V., "Simple and cost-effective measures for the improvement of paper mill effluent treatment - A case study" in Journal of Cleaner Production, 19, no. 6-7 (2011):764-774,
https://doi.org/10.1016/j.jclepro.2010.11.015 . .

TY  - JOUR
AU  - Štrbac, Svetlana
AU  - Nenadović, Miloš
AU  - Rajaković, Ljubinka V.
AU  - Rakočević, Zlatko Lj.
PY  - 2010
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/3926
AB  - High density polyethylene (HDPE) has been modified by Ag+ ion implantation with the energy of 60 keV. The total amount of implanted silver ions was 1, 5 and 12 x 10(15) ions/cm(2). The surface topography was observed by atomic forcemicroscopy (AFM), while the surface composition changes were detected using phase imaging AFM. Surface topography changes were studied in detail using 3D surface parameters analyses. The average roughness decreased for the implanted HDPE indicating the flattening of the surface. Phase AFM images indicated the homogenization of the polyethylene during ion implantation, while histogram analyses confirmed the change in surface composition. (C) 2010 Elsevier B. V. All rights reserved.
T2  - Applied Surface Science
T1  - Chemical surface composition of the polyethylene implanted by Ag+ ions studied by phase imaging atomic force microscopy
VL  - 256
IS  - 12
SP  - 3895
EP  - 3899
DO  - 10.1016/j.apsusc.2010.01.046
ER  - 

@article{
author = "Štrbac, Svetlana and Nenadović, Miloš and Rajaković, Ljubinka V. and Rakočević, Zlatko Lj.",
year = "2010",
abstract = "High density polyethylene (HDPE) has been modified by Ag+ ion implantation with the energy of 60 keV. The total amount of implanted silver ions was 1, 5 and 12 x 10(15) ions/cm(2). The surface topography was observed by atomic forcemicroscopy (AFM), while the surface composition changes were detected using phase imaging AFM. Surface topography changes were studied in detail using 3D surface parameters analyses. The average roughness decreased for the implanted HDPE indicating the flattening of the surface. Phase AFM images indicated the homogenization of the polyethylene during ion implantation, while histogram analyses confirmed the change in surface composition. (C) 2010 Elsevier B. V. All rights reserved.",
journal = "Applied Surface Science",
title = "Chemical surface composition of the polyethylene implanted by Ag+ ions studied by phase imaging atomic force microscopy",
volume = "256",
number = "12",
pages = "3895-3899",
doi = "10.1016/j.apsusc.2010.01.046"
}

Štrbac, S., Nenadović, M., Rajaković, L. V.,& Rakočević, Z. Lj.. (2010). Chemical surface composition of the polyethylene implanted by Ag+ ions studied by phase imaging atomic force microscopy. in Applied Surface Science, 256(12), 3895-3899.
https://doi.org/10.1016/j.apsusc.2010.01.046

Štrbac S, Nenadović M, Rajaković LV, Rakočević ZL. Chemical surface composition of the polyethylene implanted by Ag+ ions studied by phase imaging atomic force microscopy. in Applied Surface Science. 2010;256(12):3895-3899.
doi:10.1016/j.apsusc.2010.01.046 .

Štrbac, Svetlana, Nenadović, Miloš, Rajaković, Ljubinka V., Rakočević, Zlatko Lj., "Chemical surface composition of the polyethylene implanted by Ag+ ions studied by phase imaging atomic force microscopy" in Applied Surface Science, 256, no. 12 (2010):3895-3899,
https://doi.org/10.1016/j.apsusc.2010.01.046 . .

TY  - JOUR
AU  - Zarkovic, Darja
AU  - Todorović, Žaklina
AU  - Krgovic, Milorad
AU  - Rajaković, Ljubinka V.
PY  - 2009
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/3668
AB  - A suppressed ion chromatography (IC) method for the determination of inorganic anions in process water from paperboard production was developed and validated. Common inorganic anions (Cl(-), NO(3)(-), PO(4)(3-) and SO(4)(2-)) were detected in fresh and process water samples collected from a paperboard production system at 16 characteristic points. It was shown that the use of an IonPac (R)-AS14 column under isocratic conditions with Na(2)CO(3)/NaHCO(3) as the eluent and a suppression device proved to be a reliable analytical solution for the separation of the inorganic anions present in papermaking waters. This IC method is quite satisfactory concerning selectivity and sensitivity, and enables the determination of several inorganic anions over a wide concentration range. According to the obtained results, the total amount of analyzed inorganic anions was below 0.1 g/L, i.e., below the critical value which may trigger operational problems in paper production.
T2  - Journal of the Serbian Chemical Society
T1  - Determination of inorganic anions in papermaking waters by ion chromatography
VL  - 74
IS  - 3
SP  - 301
EP  - 310
DO  - 10.2298/JSC0903301Z
ER  - 

@article{
author = "Zarkovic, Darja and Todorović, Žaklina and Krgovic, Milorad and Rajaković, Ljubinka V.",
year = "2009",
abstract = "A suppressed ion chromatography (IC) method for the determination of inorganic anions in process water from paperboard production was developed and validated. Common inorganic anions (Cl(-), NO(3)(-), PO(4)(3-) and SO(4)(2-)) were detected in fresh and process water samples collected from a paperboard production system at 16 characteristic points. It was shown that the use of an IonPac (R)-AS14 column under isocratic conditions with Na(2)CO(3)/NaHCO(3) as the eluent and a suppression device proved to be a reliable analytical solution for the separation of the inorganic anions present in papermaking waters. This IC method is quite satisfactory concerning selectivity and sensitivity, and enables the determination of several inorganic anions over a wide concentration range. According to the obtained results, the total amount of analyzed inorganic anions was below 0.1 g/L, i.e., below the critical value which may trigger operational problems in paper production.",
journal = "Journal of the Serbian Chemical Society",
title = "Determination of inorganic anions in papermaking waters by ion chromatography",
volume = "74",
number = "3",
pages = "301-310",
doi = "10.2298/JSC0903301Z"
}

Zarkovic, D., Todorović, Ž., Krgovic, M.,& Rajaković, L. V.. (2009). Determination of inorganic anions in papermaking waters by ion chromatography. in Journal of the Serbian Chemical Society, 74(3), 301-310.
https://doi.org/10.2298/JSC0903301Z

Zarkovic D, Todorović Ž, Krgovic M, Rajaković LV. Determination of inorganic anions in papermaking waters by ion chromatography. in Journal of the Serbian Chemical Society. 2009;74(3):301-310.
doi:10.2298/JSC0903301Z .

Zarkovic, Darja, Todorović, Žaklina, Krgovic, Milorad, Rajaković, Ljubinka V., "Determination of inorganic anions in papermaking waters by ion chromatography" in Journal of the Serbian Chemical Society, 74, no. 3 (2009):301-310,
https://doi.org/10.2298/JSC0903301Z . .

TY  - JOUR
AU  - Cickaric, D
AU  - Dersek-Timotic, I
AU  - Onjia, Antonije E.
AU  - Rajaković, Ljubinka V.
PY  - 2005
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2924
AB  - A suppressed ion chromatography (IC) technique, using a carbonate/hydrogen carbonate or a hydroxide eluent, has been evaluated as a monitoring tool for the detection of major anions (F-, Cl-, NO3-, PO43- and SO42-) in ultra pure water and condensed steam from thermal power plants. An electrical conductivity detector with an anion-exchange column (IonPac AS14), an auto self-regenerating suppressor (ASRS), and an isocratic high-pressure pump system were used for the detection of low concentrations of inorganic anions. It was shown that the Suppressed IC technique provides a suitable means for preventing possible damage to generating equipment in power plants. The detection limits of the method for the anions of interest were LT 0.3 mu g/L.
T2  - Journal of the Serbian Chemical Society
T1  - Development of ion chromatography methods for the determination of trace anions in ultra pure water from power plants
VL  - 70
IS  - 7
SP  - 995
EP  - 1003
DO  - 10.2298/JSC0507995C
ER  - 

@article{
author = "Cickaric, D and Dersek-Timotic, I and Onjia, Antonije E. and Rajaković, Ljubinka V.",
year = "2005",
abstract = "A suppressed ion chromatography (IC) technique, using a carbonate/hydrogen carbonate or a hydroxide eluent, has been evaluated as a monitoring tool for the detection of major anions (F-, Cl-, NO3-, PO43- and SO42-) in ultra pure water and condensed steam from thermal power plants. An electrical conductivity detector with an anion-exchange column (IonPac AS14), an auto self-regenerating suppressor (ASRS), and an isocratic high-pressure pump system were used for the detection of low concentrations of inorganic anions. It was shown that the Suppressed IC technique provides a suitable means for preventing possible damage to generating equipment in power plants. The detection limits of the method for the anions of interest were LT 0.3 mu g/L.",
journal = "Journal of the Serbian Chemical Society",
title = "Development of ion chromatography methods for the determination of trace anions in ultra pure water from power plants",
volume = "70",
number = "7",
pages = "995-1003",
doi = "10.2298/JSC0507995C"
}

Cickaric, D., Dersek-Timotic, I., Onjia, A. E.,& Rajaković, L. V.. (2005). Development of ion chromatography methods for the determination of trace anions in ultra pure water from power plants. in Journal of the Serbian Chemical Society, 70(7), 995-1003.
https://doi.org/10.2298/JSC0507995C

Cickaric D, Dersek-Timotic I, Onjia AE, Rajaković LV. Development of ion chromatography methods for the determination of trace anions in ultra pure water from power plants. in Journal of the Serbian Chemical Society. 2005;70(7):995-1003.
doi:10.2298/JSC0507995C .

Cickaric, D, Dersek-Timotic, I, Onjia, Antonije E., Rajaković, Ljubinka V., "Development of ion chromatography methods for the determination of trace anions in ultra pure water from power plants" in Journal of the Serbian Chemical Society, 70, no. 7 (2005):995-1003,
https://doi.org/10.2298/JSC0507995C . .

TY  - JOUR
AU  - Onjia, Antonije E.
AU  - Milonjić, Slobodan K.
AU  - Rajaković, Ljubinka V.
PY  - 2002
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2506
AB  - The interactions of n-hexane, benzene, chloroform, and tetrahydrofuran with dried (amorphous) chromia (I) and chromia heated at 1073 K (crystalline) (II), both obtained from a colloidal dispersion, and a commercially available chromia (III) were Studied by inverse gas chromatography (IGC) under Finite surface coverage conditions. The isotherms, in the temperature range 383-423 K, were used to estimate the surface area, the adsorption energy distribution, the isosteric heat of adsorption, and the spreading pressure on the surfaces of the solids. The uniformly reduced adsorption ability of the heated chromia was attributed to the dehydroxylation of the surface at the higher temperatures. Both solids showed an increased affinity toward chloroform molecules, as a result of strong acid-base interaction.
T2  - Journal of the Serbian Chemical Society
T1  - Inverse gas chromatography of chromia. Part II. Finite surface coverage
VL  - 67
IS  - 3
SP  - 165
EP  - 178
DO  - 10.2298/JSC0203165O
ER  - 

@article{
author = "Onjia, Antonije E. and Milonjić, Slobodan K. and Rajaković, Ljubinka V.",
year = "2002",
abstract = "The interactions of n-hexane, benzene, chloroform, and tetrahydrofuran with dried (amorphous) chromia (I) and chromia heated at 1073 K (crystalline) (II), both obtained from a colloidal dispersion, and a commercially available chromia (III) were Studied by inverse gas chromatography (IGC) under Finite surface coverage conditions. The isotherms, in the temperature range 383-423 K, were used to estimate the surface area, the adsorption energy distribution, the isosteric heat of adsorption, and the spreading pressure on the surfaces of the solids. The uniformly reduced adsorption ability of the heated chromia was attributed to the dehydroxylation of the surface at the higher temperatures. Both solids showed an increased affinity toward chloroform molecules, as a result of strong acid-base interaction.",
journal = "Journal of the Serbian Chemical Society",
title = "Inverse gas chromatography of chromia. Part II. Finite surface coverage",
volume = "67",
number = "3",
pages = "165-178",
doi = "10.2298/JSC0203165O"
}

Onjia, A. E., Milonjić, S. K.,& Rajaković, L. V.. (2002). Inverse gas chromatography of chromia. Part II. Finite surface coverage. in Journal of the Serbian Chemical Society, 67(3), 165-178.
https://doi.org/10.2298/JSC0203165O

Onjia AE, Milonjić SK, Rajaković LV. Inverse gas chromatography of chromia. Part II. Finite surface coverage. in Journal of the Serbian Chemical Society. 2002;67(3):165-178.
doi:10.2298/JSC0203165O .

Onjia, Antonije E., Milonjić, Slobodan K., Rajaković, Ljubinka V., "Inverse gas chromatography of chromia. Part II. Finite surface coverage" in Journal of the Serbian Chemical Society, 67, no. 3 (2002):165-178,
https://doi.org/10.2298/JSC0203165O . .

TY  - JOUR
AU  - Onjia, Antonije E.
AU  - Milonjić, Slobodan K.
AU  - Rajaković, Ljubinka V.
PY  - 2001
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2434
AB  - The surface properties of the solid obtained from colloidal chromia were investigated by inverse gas chromatography (IGC), at zero surface coverage conditions. The solid samples I dried at 423 K and II healed at 1073 K in the amorphous and crystalline form, respectively, were studied in the temperature range 383-423 K. The dispersive components of the surface free energies, enthalpies, entropies, and the acid/bass constants for the solids wore calculated from the IGC measurements and compared with the data for a commercially available chromia (III). Significantly lower enthalpies and entropies were obtained for cyclohexane on solid II and chloroform, highly polar organic, on solid I. The dispersive contributions to the surface energy of solid II and III were similar but much greater in the case of solid I. All the sorbents had a basic character, with the K-D/K-A ratio decreasing in the order I GT II GT III. The retention and resolution in thr separation of a vapour mixture of C-5-C-8 n-alkanes on the three substrates were different. A rapid separation was observed on solid II and an enhanced I retention on solid I. Generally, the heated chromia (II) exhibited diminished adsorption capacity, and enhanced homogeneity of the surface.
T2  - Journal of the Serbian Chemical Society
T1  - Inverse gas chromatography of chromia. Part I. Zero surface coverage
VL  - 66
IS  - 4
SP  - 259
EP  - 271
UR  - https://hdl.handle.net/21.15107/rcub_vinar_2434
ER  - 

@article{
author = "Onjia, Antonije E. and Milonjić, Slobodan K. and Rajaković, Ljubinka V.",
year = "2001",
abstract = "The surface properties of the solid obtained from colloidal chromia were investigated by inverse gas chromatography (IGC), at zero surface coverage conditions. The solid samples I dried at 423 K and II healed at 1073 K in the amorphous and crystalline form, respectively, were studied in the temperature range 383-423 K. The dispersive components of the surface free energies, enthalpies, entropies, and the acid/bass constants for the solids wore calculated from the IGC measurements and compared with the data for a commercially available chromia (III). Significantly lower enthalpies and entropies were obtained for cyclohexane on solid II and chloroform, highly polar organic, on solid I. The dispersive contributions to the surface energy of solid II and III were similar but much greater in the case of solid I. All the sorbents had a basic character, with the K-D/K-A ratio decreasing in the order I GT II GT III. The retention and resolution in thr separation of a vapour mixture of C-5-C-8 n-alkanes on the three substrates were different. A rapid separation was observed on solid II and an enhanced I retention on solid I. Generally, the heated chromia (II) exhibited diminished adsorption capacity, and enhanced homogeneity of the surface.",
journal = "Journal of the Serbian Chemical Society",
title = "Inverse gas chromatography of chromia. Part I. Zero surface coverage",
volume = "66",
number = "4",
pages = "259-271",
url = "https://hdl.handle.net/21.15107/rcub_vinar_2434"
}

Onjia, A. E., Milonjić, S. K.,& Rajaković, L. V.. (2001). Inverse gas chromatography of chromia. Part I. Zero surface coverage. in Journal of the Serbian Chemical Society, 66(4), 259-271.
https://hdl.handle.net/21.15107/rcub_vinar_2434

Onjia AE, Milonjić SK, Rajaković LV. Inverse gas chromatography of chromia. Part I. Zero surface coverage. in Journal of the Serbian Chemical Society. 2001;66(4):259-271.
https://hdl.handle.net/21.15107/rcub_vinar_2434 .

Onjia, Antonije E., Milonjić, Slobodan K., Rajaković, Ljubinka V., "Inverse gas chromatography of chromia. Part I. Zero surface coverage" in Journal of the Serbian Chemical Society, 66, no. 4 (2001):259-271,
https://hdl.handle.net/21.15107/rcub_vinar_2434 .