scholarly journals Label Distribution in Tissues of Wheat Seedlings Cultivated with Tritium-Labeled Leonardite Humic Acid

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Natalia A. Kulikova ◽  
Dmitry P. Abroskin ◽  
Gennady A. Badun ◽  
Maria G. Chernysheva ◽  
Viktor I. Korobkov ◽  
...  
Keyword(s):  
Humic Acid ◽  
Wheat Seedlings ◽  
Label Distribution ◽  
Leonardite Humic Acid

Sorption Equilibrium of a Wide Spectrum of Organic Vapors in Leonardite Humic Acid:  Modeling of Experimental Data

2006 ◽  
Vol 40 (17) ◽  
pp. 5374-5379 ◽  
Author(s):  
Christian Niederer ◽  
Kai-Uwe Goss ◽  
René P. Schwarzenbach
Keyword(s):  
Experimental Data ◽  
Humic Acid ◽  
Wide Spectrum ◽  
Sorption Equilibrium ◽  
Organic Vapors ◽  
Leonardite Humic Acid

Sorption Equilibrium of a Wide Spectrum of Organic Vapors in Leonardite Humic Acid:  Experimental Setup and Experimental Data

2006 ◽  
Vol 40 (17) ◽  
pp. 5368-5373 ◽  
Author(s):  
Christian Niederer ◽  
Kai-Uwe Goss ◽  
René P. Schwarzenbach
Keyword(s):  
Experimental Data ◽  
Humic Acid ◽  
Wide Spectrum ◽  
Experimental Setup ◽  
Sorption Equilibrium ◽  
Organic Vapors ◽  
Leonardite Humic Acid

The root application of a purified leonardite humic acid modifies the transcriptional regulation of the main physiological root responses to Fe deficiency in Fe-sufficient cucumber plants

2009 ◽  
Vol 47 (3) ◽  
pp. 215-223 ◽  
Author(s):  
Aguirre Elena ◽  
Leménager Diane ◽  
Bacaicoa Eva ◽  
Fuentes Marta ◽  
Baigorri Roberto ◽  
...  
Keyword(s):  
Transcriptional Regulation ◽  
Humic Acid ◽  
Fe Deficiency ◽  
Root Responses ◽  
Leonardite Humic Acid

Aggregation and stabilization of multiwalled carbon nanotubes in aqueous suspensions: influences of carboxymethyl cellulose, starch and humic acid

RSC Advances ◽  
2016 ◽  
Vol 6 (71) ◽  
pp. 67260-67270 ◽  
Author(s):  
Wen Liu ◽  
Xiao Zhao ◽  
Zhengqing Cai ◽  
Bing Han ◽  
Dongye Zhao
Keyword(s):  
Carbon Nanotubes ◽  
Organic Matter ◽  
Humic Acid ◽  
Multiwalled Carbon Nanotubes ◽  
Natural Organic Matter ◽  
Carboxymethyl Cellulose ◽  
Soluble Starch ◽  
Water Soluble ◽  
Multiwalled Carbon ◽  
Leonardite Humic Acid

Aggregation and stability of multiwalled carbon nanotubes in aqueous solutions were investigated with two polysaccharide stabilizers (carboxymethyl cellulose and a water soluble starch) and a natural organic matter (leonardite humic acid).

scholarly journals Molecular Dynamics Simulations of the Standard Leonardite Humic Acid: Microscopic Analysis of the Structure and Dynamics

2017 ◽  
Vol 51 (10) ◽  
pp. 5414-5424 ◽  
Author(s):  
Drazen Petrov ◽  
Daniel Tunega ◽  
Martin H. Gerzabek ◽  
Chris Oostenbrink
Keyword(s):  
Molecular Dynamics ◽  
Humic Acid ◽  
Molecular Dynamics Simulations ◽  
Microscopic Analysis ◽  
Structure And Dynamics ◽  
Dynamics Simulations ◽  
Leonardite Humic Acid

scholarly journals Hg-Pb binary heavy metals interaction study with Humic Acid: monitoring by FTIR spectroscopy

2020 ◽  
Vol 10 (2) ◽  
pp. 121
Author(s):  
Mohamed Cherif Terkhi ◽  
Mouffok Redouane Ghezzar ◽  
Ahmed Addou
Keyword(s):  
Humic Acid ◽  
Humic Acids ◽  
Binary Solution ◽  
Binary Interaction ◽  
Vibration Band ◽  
Interaction Study ◽  
High Concentration ◽  
Analytical Technique ◽  
Stretching Vibration ◽  
Leonardite Humic Acid

<p>This work shows that infrared spectroscopy is an easy and fast analytical technique for monitoring the behavior of the humic acids Fluka and Leonardite in contact with binary solutions of mercury and lead. Given the complexity of the structure of humic acid, the experiments were carried out on simple model molecules.<strong></strong></p><p>The spectra showed a shift (30 cm<sup>-1</sup>) of the antisymmetric stretching vibration band from the carboxylate function -COO<sup>-</sup> from 1590 to 1560 cm<sup>-1</sup> for the humic acids Fluka-binary solution interaction. In the case of mercury alone, the shift was of 40 cm<sup>-1</sup>, it can be seen that this shift has dropped by 10cm<sup>-1</sup>, which proves that the cationic exchange becomes more difficult.<strong></strong></p><p>We have confirmed that the affinity is due to the ionic radius, the reduction potential and the ionic potential. We reinforced this by a fourth parameter which is the frequency separations between the-COO<sup>-</sup> antisymmetric and symmetric stretches (Dn<sub>as-s</sub>). We have found thatDn<sub>as-s </sub>is strongly related to the type of fixed metal. The spectra also showed the variation of the intensity of the C=O elongation vibration band of the carboxylic function -COOH up to 1610 cm<sup>-1</sup> for the Leonardite humic acid-binary interaction. The high concentration of the binary solution did not result in the total disappearance of the C=O band as in the Leonardite humic acid-mercury alone interaction study. This proves that some carboxylic sites are not accessible to Hg<sup>2+</sup> ions.</p>

Molecular characteristics of leonardite humic acid and the effect of its fractionations on sulfamethoxazole photodegradation

Chemosphere ◽  
2020 ◽  
Vol 246 ◽  
pp. 125642 ◽  
Author(s):  
Yiyue Zhang ◽  
Furong Zhao ◽  
Fei Wang ◽  
Yahe Zhang ◽  
Quan Shi ◽  
...  
Keyword(s):  
Humic Acid ◽  
Molecular Characteristics ◽  
Leonardite Humic Acid

Complexation of TbIII with size fractions of humic acid: evidence from luminescence sensitisation and anisotropy measurements

2007 ◽  
Vol 4 (3) ◽  
pp. 204 ◽  
Author(s):  
Jeremy Riggle ◽  
Ray von Wandruszka
Keyword(s):  
Humic Acid ◽  
Metal Ions ◽  
Fate And Transport ◽  
Humic Material ◽  
Size Fractions ◽  
Vis Spectroscopy ◽  
Good Energy ◽  
Trivalent Metal Ions ◽  
Luminescence Anisotropy ◽  
Leonardite Humic Acid

Environmental context. Organic ligands, especially those derived from humic acid (HA), play a major role in the fate and transport of metal ions in the environment. For the modelling of subsurface pollutant transport, it is important to understand which components of a heterogeneous humic material interact most strongly with multivalent cations. Abstract. The luminescence sensitisation and anisotropy characteristics of a series of TbIII complexes with a leonardite humic acid (LHA) were investigated in order to evaluate the interactions between the metal and different components of the humate. Ultrafiltration was used to separate LHA into six size fractions, which ranged from 500 Da to 0.2 μm, and were then used to form the TbIII complexes. Each fraction was first characterised by 13C NMR and UV-Vis spectroscopy, which showed that the smaller ones (<3 kDa) had a significantly lower aliphatic content than the larger ones. These smaller components were good energy donors, which could effectively sensitise TbIII luminescence. At the same time, the luminescence anisotropy of TbIII increased significantly when these LHA fractions were added, which indicated the formation of tightly bound complexes. In this sense, the smaller LHA fractions were comparable to ethylenediaminetetraacetate, although their effect was not as strong. In contrast, the larger LHA sizes had little or no influence on TbIII sensitisation or anisotropy. The results obtained suggest that the sizes and aliphatic content of humic polymers play a major role in their aqueous interactions with trivalent metal ions. Divalent metals are expected to behave in a similar way.

scholarly journals Strength of Flocs Formed by the Complexation of Lysozyme with Leonardite Humic Acid

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1770
Author(s):  
Wan Khairunnisa Wan Abdul Khodir ◽  
Azizul Hakim ◽  
Motoyoshi Kobayashi
Keyword(s):  
Humic Acid ◽  
Humic Substances ◽  
Isoelectric Point ◽  
Salt Concentration ◽  
Positive Charge ◽  
Mass Ratio ◽  
Low Salt ◽  
Floc Strength ◽  
Soil And Water ◽  
Leonardite Humic Acid

Aggregation and aggregates properties of natural organic and nanosized macromolecules such as humic substances and proteins are crucial to explore so-called colloid-mediated transport and the fate of substances in soil and water environments. Therefore, the aggregation and dispersion, charging, and floc strength of lysozyme (LSZ)–leonardite humic acid (LHA) flocs were experimentally investigated. The experiments were performed in different salt concentrations and LSZ to LHA mass ratios as a function of pH. We obtained the stronger flocs at pH 4.4, where the isoelectric point (IEP) of the complex with the mass ratio 2.5 was confirmed. Thus, the aggregation of LSZ–LHA flocs is mainly caused by charge neutralization. We obtained the floc strength of 4.7 nN around IEP at low salt concentration of 3 mM, which was stronger than 2.8 nN in high salt concentration of 50 mM. The effect of salt concentration can be rationalized by charge-patch attraction at low salt concentration. With increasing mass ratio, the IEP shifted to higher pH. This is due to the increase in positive charge from LSZ in the mixture. The effect of the LSZ to LHA mass ratio on the maximum strength was weak in the range studied.

Models for Association of Metal Ions with Heterogeneous Environmental Sorbents. 1. Complexation of Co(II) by Leonardite Humic Acid as a Function of pH and NaClO4 Concentration

1995 ◽  
Vol 29 (4) ◽  
pp. 951-959 ◽  
Author(s):  
John C. Westall ◽  
John D. Jones ◽  
Gary D. Turner ◽  
John M. Zachara
Keyword(s):  
Humic Acid ◽  
Metal Ions ◽  
Leonardite Humic Acid
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