Soil humic acid aggregation by dynamic light scattering and laser Doppler electrophoresis
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 de...pendence 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.
Keywords:
particle size / zeta potential / Rendzic Leptosol / Elliot soilSource:
Journal of Plant Nutrition and Soil Science, 2013, 176, 5, 674-679Funding / projects:
- Synthesis, processing and characterization of nanostructured materials for application in the field of energy, mechanical engineering, environmental protection and biomedicine (RS-MESTD-Integrated and Interdisciplinary Research (IIR or III)-45012)
DOI: 10.1002/jpln.201200346
ISSN: 1436-8730; 1522-2624
WoS: 000327899800004
Scopus: 2-s2.0-84884973892
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VinčaTY - JOUR AU - Jovanović, Uroš D. AU - Marković, Mirjana AU - Cupać, Svjetlana AU - Tomić, Zorica P. PY - 2013 UR - https://vinar.vin.bg.ac.rs/handle/123456789/5778 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. T2 - Journal of Plant Nutrition and Soil Science T1 - Soil humic acid aggregation by dynamic light scattering and laser Doppler electrophoresis VL - 176 IS - 5 SP - 674 EP - 679 DO - 10.1002/jpln.201200346 ER -
@article{ author = "Jovanović, Uroš D. and Marković, Mirjana and Cupać, Svjetlana and Tomić, Zorica P.", 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.", journal = "Journal of Plant Nutrition and Soil Science", title = "Soil humic acid aggregation by dynamic light scattering and laser Doppler electrophoresis", volume = "176", number = "5", pages = "674-679", doi = "10.1002/jpln.201200346" }
Jovanović, U. D., Marković, M., Cupać, S.,& Tomić, Z. P.. (2013). Soil humic acid aggregation by dynamic light scattering and laser Doppler electrophoresis. in Journal of Plant Nutrition and Soil Science, 176(5), 674-679. https://doi.org/10.1002/jpln.201200346
Jovanović UD, Marković M, Cupać S, Tomić ZP. 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, Cupać, Svjetlana, Tomić, Zorica P., "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 . .