TY  - CONF
AU  - Čokeša, Đuro
AU  - Marković, Mirjana
AU  - Potkonjak, Nebojša
AU  - Kaluđerović, Branka
AU  - Radmanović, Svjetlana
AU  - Šerbula, Snežana
PY  - 2023
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/6692
AB  - Arsenite–humic acid-binding process was investigated using the Isothermal Titration Calorimetry
(ITC). The ITC data were successfully (R2=0.996-0.936) interpreted by applying the MNIS model,
enabling thermodynamic parameters to be determined. The MNIS model was adjusted to the arsenite–
HA binding process assuming hydrogen bonding as the dominant type of interaction in the system.
Negative enthalpy change values indicated the arsenite–HAs binding as an exothermic process.
Negative ΔG values (-(27.85-26.83) kJ mol-1) pointed out to spontaneous binding reaction, leading to
the formation of the arsenite–HA complexes. High binding constants values ((7.57-5.02)105 M-1)
clearly demonstrated pronounced binding affinity. As ΔS values (0.041-0.027) kJ mol-1 K-1) were
apparently positive, but close to zero, and ΔH>ΔS, the reaction could be considered enthalpy driven.
Reaction heats and H values (-(18.96-15.64) kJ mol-1) confirmed hydrogen bonds as the most
ascendant interaction type in the arsenite–HA complex. Thermodynamic and reaction parameters
clearly indicated that arsenite–HA complexes are formed at common soil pH values, confirming the
possible influence of humic acids on increased As mobility, and its reduced bioavailability.
PB  - University of Belgrade, Technical Faculty in Bor
C3  - 29th INTERNATIONAL CONFERENCE ECOLOGICAL TRUTH AND ENVIRONMENTAL RESEARCH – EcoTER’22, Sokobanja, Serbia
T1  - ARSENITE–SOIL HUMIC ACID BINDING BY ISOTHERMAL TITRATION CALORIMETRY: THERMODYNAMICS AND MNIS MODEL
EP  - 126
SP  - 121
UR  - https://hdl.handle.net/21.15107/rcub_agrospace_6692
ER  - 

@conference{
author = "Čokeša, Đuro and Marković, Mirjana and Potkonjak, Nebojša and Kaluđerović, Branka and Radmanović, Svjetlana and Šerbula, Snežana",
year = "2023",
abstract = "Arsenite–humic acid-binding process was investigated using the Isothermal Titration Calorimetry
(ITC). The ITC data were successfully (R2=0.996-0.936) interpreted by applying the MNIS model,
enabling thermodynamic parameters to be determined. The MNIS model was adjusted to the arsenite–
HA binding process assuming hydrogen bonding as the dominant type of interaction in the system.
Negative enthalpy change values indicated the arsenite–HAs binding as an exothermic process.
Negative ΔG values (-(27.85-26.83) kJ mol-1) pointed out to spontaneous binding reaction, leading to
the formation of the arsenite–HA complexes. High binding constants values ((7.57-5.02)105 M-1)
clearly demonstrated pronounced binding affinity. As ΔS values (0.041-0.027) kJ mol-1 K-1) were
apparently positive, but close to zero, and ΔH>ΔS, the reaction could be considered enthalpy driven.
Reaction heats and H values (-(18.96-15.64) kJ mol-1) confirmed hydrogen bonds as the most
ascendant interaction type in the arsenite–HA complex. Thermodynamic and reaction parameters
clearly indicated that arsenite–HA complexes are formed at common soil pH values, confirming the
possible influence of humic acids on increased As mobility, and its reduced bioavailability.",
publisher = "University of Belgrade, Technical Faculty in Bor",
journal = "29th INTERNATIONAL CONFERENCE ECOLOGICAL TRUTH AND ENVIRONMENTAL RESEARCH – EcoTER’22, Sokobanja, Serbia",
title = "ARSENITE–SOIL HUMIC ACID BINDING BY ISOTHERMAL TITRATION CALORIMETRY: THERMODYNAMICS AND MNIS MODEL",
pages = "126-121",
url = "https://hdl.handle.net/21.15107/rcub_agrospace_6692"
}

Čokeša, Đ., Marković, M., Potkonjak, N., Kaluđerović, B., Radmanović, S.,& Šerbula, S.. (2023). ARSENITE–SOIL HUMIC ACID BINDING BY ISOTHERMAL TITRATION CALORIMETRY: THERMODYNAMICS AND MNIS MODEL. in 29th INTERNATIONAL CONFERENCE ECOLOGICAL TRUTH AND ENVIRONMENTAL RESEARCH – EcoTER’22, Sokobanja, Serbia
University of Belgrade, Technical Faculty in Bor., 121-126.
https://hdl.handle.net/21.15107/rcub_agrospace_6692

Čokeša Đ, Marković M, Potkonjak N, Kaluđerović B, Radmanović S, Šerbula S. ARSENITE–SOIL HUMIC ACID BINDING BY ISOTHERMAL TITRATION CALORIMETRY: THERMODYNAMICS AND MNIS MODEL. in 29th INTERNATIONAL CONFERENCE ECOLOGICAL TRUTH AND ENVIRONMENTAL RESEARCH – EcoTER’22, Sokobanja, Serbia. 2023;:121-126.
https://hdl.handle.net/21.15107/rcub_agrospace_6692 .

Čokeša, Đuro, Marković, Mirjana, Potkonjak, Nebojša, Kaluđerović, Branka, Radmanović, Svjetlana, Šerbula, Snežana, "ARSENITE–SOIL HUMIC ACID BINDING BY ISOTHERMAL TITRATION CALORIMETRY: THERMODYNAMICS AND MNIS MODEL" in 29th INTERNATIONAL CONFERENCE ECOLOGICAL TRUTH AND ENVIRONMENTAL RESEARCH – EcoTER’22, Sokobanja, Serbia (2023):121-126,
https://hdl.handle.net/21.15107/rcub_agrospace_6692 .

TY  - JOUR
AU  - Jovanović, Uroš D.
AU  - Marković, Mirjana M.
AU  - Čokeša, Đuro M.
AU  - Živković, Nikola V.
AU  - Radmanović, Svjetlana B.
PY  - 2022
UR  - http://www.doiserbia.nb.rs/Article.aspx?ID=0352-51392200010J
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/6139
AB  - The main goal of this work was to estimate the influence of carboxyl and phenolic groups, as well as aromatic, aliphatic and polysaccharide components, on the soil humic acids (HA) self-aggregation process. Soil HAs (leptosol and regosol) were separated using base resin getting fractions with different functional group contents. Blocking of carboxyl groups was performed using the esterification procedure to estimate the participation of each functional group in the HA aggregation. The presence of HA structural components was evaluated by potentiometric titration and ATR-FTIR. The aggregation was monitored at pH 3 using dynamic light scattering. Results indicated that the higher group content, the HA aggregation is less pronounced. A significant positive correlation of aliphatic C and aggregate size revealed their dominant influence in the HA self-aggregation. A lower abundance of aliphatic C in HA fractions could be considered as not sufficient to start the process. An increase of aromatic C in esters likely pointed out to its participation in hydrophobic bonding and, consequently, more pronounced aggregation. The relation of HA self-aggregate size with carboxyl and phenolic group, as well as aliphatic C, at low pH, could be considered universal regardless of the structural characteristics of the original or modified HA forms.
T2  - Journal of the Serbian Chemical Society
T2  - Journal of the Serbian Chemical Society
T1  - Self-aggregation of soil humic acids with respect to their structural characteristics
EP  - 773
IS  - 6
SP  - 761
VL  - 87
UR  - https://hdl.handle.net/21.15107/rcub_agrospace_6139
ER  - 

@article{
author = "Jovanović, Uroš D. and Marković, Mirjana M. and Čokeša, Đuro M. and Živković, Nikola V. and Radmanović, Svjetlana B.",
year = "2022",
abstract = "The main goal of this work was to estimate the influence of carboxyl and phenolic groups, as well as aromatic, aliphatic and polysaccharide components, on the soil humic acids (HA) self-aggregation process. Soil HAs (leptosol and regosol) were separated using base resin getting fractions with different functional group contents. Blocking of carboxyl groups was performed using the esterification procedure to estimate the participation of each functional group in the HA aggregation. The presence of HA structural components was evaluated by potentiometric titration and ATR-FTIR. The aggregation was monitored at pH 3 using dynamic light scattering. Results indicated that the higher group content, the HA aggregation is less pronounced. A significant positive correlation of aliphatic C and aggregate size revealed their dominant influence in the HA self-aggregation. A lower abundance of aliphatic C in HA fractions could be considered as not sufficient to start the process. An increase of aromatic C in esters likely pointed out to its participation in hydrophobic bonding and, consequently, more pronounced aggregation. The relation of HA self-aggregate size with carboxyl and phenolic group, as well as aliphatic C, at low pH, could be considered universal regardless of the structural characteristics of the original or modified HA forms.",
journal = "Journal of the Serbian Chemical Society, Journal of the Serbian Chemical Society",
title = "Self-aggregation of soil humic acids with respect to their structural characteristics",
pages = "773-761",
number = "6",
volume = "87",
url = "https://hdl.handle.net/21.15107/rcub_agrospace_6139"
}

Jovanović, U. D., Marković, M. M., Čokeša, Đ. M., Živković, N. V.,& Radmanović, S. B.. (2022). Self-aggregation of soil humic acids with respect to their structural characteristics. in Journal of the Serbian Chemical Society, 87(6), 761-773.
https://hdl.handle.net/21.15107/rcub_agrospace_6139

Jovanović UD, Marković MM, Čokeša ĐM, Živković NV, Radmanović SB. Self-aggregation of soil humic acids with respect to their structural characteristics. in Journal of the Serbian Chemical Society. 2022;87(6):761-773.
https://hdl.handle.net/21.15107/rcub_agrospace_6139 .

Jovanović, Uroš D., Marković, Mirjana M., Čokeša, Đuro M., Živković, Nikola V., Radmanović, Svjetlana B., "Self-aggregation of soil humic acids with respect to their structural characteristics" in Journal of the Serbian Chemical Society, 87, no. 6 (2022):761-773,
https://hdl.handle.net/21.15107/rcub_agrospace_6139 .

TY  - JOUR
AU  - Radmanović, Svjetlana
AU  - Marković, Mirjana M.
AU  - Jovanović, Uroš D.
AU  - Gajić-Kvascev, Maja D.
AU  - Čokeša, Djuro M.
AU  - Lilić, Jasmina A.
PY  - 2020
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/5393
AB  - Part of Cu post flotation tailings of Serbia ZiJin Bor Copper, Serbia, was reclaimed by restoration of top soil with arable soils, and revegetation in 1991. Humic acids isolated from these Technosols were investigated to find out if their properties underwent any changes since reclamation. Two groups of control samples were used. Elemental composition (CHNS analysis) falls within the range of average soil humic acids. Humic acids belong to the type B pointing out to its lower humification degree (UV-Vis). Relative abundances of functional groups are ranged as follows: polysaccharide C >= aromatic C > carboxyl C > OH group > aliphatic C. Aromaticity indexes are low, 1.883.25 (ATR-FTIR). Basic units at pH 10 are in the 11.7-26.8 nm range. Pronounced reaggregation (1462--5218 nm) at pH 3 points out to less expressed humic acid sol stability, as well as to increase in aromatic condensation degree (dynamic light scattering). No significant changes have occurred in technosol humic acids since the recultivation, confirming stability of their properties over time (PCA). Nevertheless, humic acids from very strongly acidic Technosols show higher humifycation degree possibly originating from arable soils used in reclamation, but more likely from low soil pH and low litter input, results of unsuccessful reclamation.
PB  - Srpsko hemijsko društvo, Beograd
T2  - JOURNAL OF THE SERBIAN CHEMICAL SOCIETY
T1  - Properties of humic acids from copper tailings 20 years after reclamation
EP  - 419
IS  - 3
SP  - 407
VL  - 85
DO  - 10.2298/JSC190717112R
ER  - 

@article{
author = "Radmanović, Svjetlana and Marković, Mirjana M. and Jovanović, Uroš D. and Gajić-Kvascev, Maja D. and Čokeša, Djuro M. and Lilić, Jasmina A.",
year = "2020",
abstract = "Part of Cu post flotation tailings of Serbia ZiJin Bor Copper, Serbia, was reclaimed by restoration of top soil with arable soils, and revegetation in 1991. Humic acids isolated from these Technosols were investigated to find out if their properties underwent any changes since reclamation. Two groups of control samples were used. Elemental composition (CHNS analysis) falls within the range of average soil humic acids. Humic acids belong to the type B pointing out to its lower humification degree (UV-Vis). Relative abundances of functional groups are ranged as follows: polysaccharide C >= aromatic C > carboxyl C > OH group > aliphatic C. Aromaticity indexes are low, 1.883.25 (ATR-FTIR). Basic units at pH 10 are in the 11.7-26.8 nm range. Pronounced reaggregation (1462--5218 nm) at pH 3 points out to less expressed humic acid sol stability, as well as to increase in aromatic condensation degree (dynamic light scattering). No significant changes have occurred in technosol humic acids since the recultivation, confirming stability of their properties over time (PCA). Nevertheless, humic acids from very strongly acidic Technosols show higher humifycation degree possibly originating from arable soils used in reclamation, but more likely from low soil pH and low litter input, results of unsuccessful reclamation.",
publisher = "Srpsko hemijsko društvo, Beograd",
journal = "JOURNAL OF THE SERBIAN CHEMICAL SOCIETY",
title = "Properties of humic acids from copper tailings 20 years after reclamation",
pages = "419-407",
number = "3",
volume = "85",
doi = "10.2298/JSC190717112R"
}

Radmanović, S., Marković, M. M., Jovanović, U. D., Gajić-Kvascev, M. D., Čokeša, D. M.,& Lilić, J. A.. (2020). Properties of humic acids from copper tailings 20 years after reclamation. in JOURNAL OF THE SERBIAN CHEMICAL SOCIETY
Srpsko hemijsko društvo, Beograd., 85(3), 407-419.
https://doi.org/10.2298/JSC190717112R

Radmanović S, Marković MM, Jovanović UD, Gajić-Kvascev MD, Čokeša DM, Lilić JA. Properties of humic acids from copper tailings 20 years after reclamation. in JOURNAL OF THE SERBIAN CHEMICAL SOCIETY. 2020;85(3):407-419.
doi:10.2298/JSC190717112R .

Radmanović, Svjetlana, Marković, Mirjana M., Jovanović, Uroš D., Gajić-Kvascev, Maja D., Čokeša, Djuro M., Lilić, Jasmina A., "Properties of humic acids from copper tailings 20 years after reclamation" in JOURNAL OF THE SERBIAN CHEMICAL SOCIETY, 85, no. 3 (2020):407-419,
https://doi.org/10.2298/JSC190717112R . .

TY  - JOUR
AU  - Jovanović, Uroš D.
AU  - Marković, Mirjana M.
AU  - Cupać, Svjetlana
AU  - Tomić, Zorica
PY  - 2013
UR  - http://aspace.agrif.bg.ac.rs/handle/123456789/3093
AB  - Humic acids (HAs), similar to other fractions of humic substances (HSs), have a large number of reactive functional groups enabling them to aggregate in solutions. Regardless of the origin of humic acid (aqueous or soil), this aggregation process is dependent on environmental conditions and strongly influences the mobility of soluble ionic and molecular pollutants. The aim of this work was to monitor the aggregation process of two humic acids isolated from different mineral soils (IHSS Elliot soil HA standard and Rendzic Leptosol HA) in the 2-11 pH range. Changes in aggregate size in HA sols were followed up using dynamic light scattering (DLS), while zeta potential (ZP) measurements in the same pH range were performed applying laser Doppler electrophoresis (LDE) technique. The effect of HA sol concentration and soil source on aggregation was examined as well. Besides, HA samples were characterized using Fourier transform infrared (FT-IR) spectroscopy. By inspecting HA-particle-size dependence on pH, it can be concluded that both HAs in corresponding sols behave as molecular aggregates or supramolecular structures, formed from small individual moieties (sizes  lt  10 nm) at higher pH values. The ZP vs. pH curve for both HAs revealed the ZP minimum in the 5-7 pH range, caused most likely by dissociation of acidic functional groups prevailing at lower pH values and deaggregation predominating over dissociation at higher pH values.
PB  - Wiley-V C H Verlag Gmbh, Weinheim
T2  - Journal of Plant Nutrition and Soil Science
T1  - Soil humic acid aggregation by dynamic light scattering and laser Doppler electrophoresis
EP  - 679
IS  - 5
SP  - 674
VL  - 176
DO  - 10.1002/jpln.201200346
ER  - 

@article{
author = "Jovanović, Uroš D. and Marković, Mirjana M. and Cupać, Svjetlana and Tomić, Zorica",
year = "2013",
abstract = "Humic acids (HAs), similar to other fractions of humic substances (HSs), have a large number of reactive functional groups enabling them to aggregate in solutions. Regardless of the origin of humic acid (aqueous or soil), this aggregation process is dependent on environmental conditions and strongly influences the mobility of soluble ionic and molecular pollutants. The aim of this work was to monitor the aggregation process of two humic acids isolated from different mineral soils (IHSS Elliot soil HA standard and Rendzic Leptosol HA) in the 2-11 pH range. Changes in aggregate size in HA sols were followed up using dynamic light scattering (DLS), while zeta potential (ZP) measurements in the same pH range were performed applying laser Doppler electrophoresis (LDE) technique. The effect of HA sol concentration and soil source on aggregation was examined as well. Besides, HA samples were characterized using Fourier transform infrared (FT-IR) spectroscopy. By inspecting HA-particle-size dependence on pH, it can be concluded that both HAs in corresponding sols behave as molecular aggregates or supramolecular structures, formed from small individual moieties (sizes  lt  10 nm) at higher pH values. The ZP vs. pH curve for both HAs revealed the ZP minimum in the 5-7 pH range, caused most likely by dissociation of acidic functional groups prevailing at lower pH values and deaggregation predominating over dissociation at higher pH values.",
publisher = "Wiley-V C H Verlag Gmbh, Weinheim",
journal = "Journal of Plant Nutrition and Soil Science",
title = "Soil humic acid aggregation by dynamic light scattering and laser Doppler electrophoresis",
pages = "679-674",
number = "5",
volume = "176",
doi = "10.1002/jpln.201200346"
}

Jovanović, U. D., Marković, M. M., Cupać, S.,& Tomić, Z.. (2013). Soil humic acid aggregation by dynamic light scattering and laser Doppler electrophoresis. in Journal of Plant Nutrition and Soil Science
Wiley-V C H Verlag Gmbh, Weinheim., 176(5), 674-679.
https://doi.org/10.1002/jpln.201200346

Jovanović UD, Marković MM, Cupać S, Tomić Z. Soil humic acid aggregation by dynamic light scattering and laser Doppler electrophoresis. in Journal of Plant Nutrition and Soil Science. 2013;176(5):674-679.
doi:10.1002/jpln.201200346 .

Jovanović, Uroš D., Marković, Mirjana M., Cupać, Svjetlana, Tomić, Zorica, "Soil humic acid aggregation by dynamic light scattering and laser Doppler electrophoresis" in Journal of Plant Nutrition and Soil Science, 176, no. 5 (2013):674-679,
https://doi.org/10.1002/jpln.201200346 . .