Radio-Labelled Humic Materials in Migration Studies

1992 ◽  
Vol 294 ◽  
Author(s):  
Lars Carlsen ◽  
Pia Lassen ◽  
Peter Warwick ◽  
Amanda Randall

ABSTRACTHumic- and fulvic acids are able to complex polyvalent metal ions, e.g. radionuclides, leading to soluble complexes of significant strength, thereby decreasing the sorption of these compounds to soils and sediments. The interaction of humic materials with radionuclides may significantly influence the availability and transport of the latter in the environment. Typically, studies along these lines have focussed almost exclusively on the radionuclides, whereas the actual role of the humic material has been elucidated only indirectly. In order directly to study the behaviour of the naturally occurring organic macro-molecules in relation to the environmental fate of radionuclides, radio-labelled humic- and fulvic acids can advantageously be applied. Radio-labels such as 14C and 125I have successfully been covalently incorporated in humic- and fulvic acids. Labelling of humic substances as well as preliminary migration studies are discussed

2008 ◽  
Vol 38 (6) ◽  
pp. 1646-1660 ◽  
Author(s):  
Pavel Šamonil ◽  
Barbora Šebková ◽  
Jan Douda ◽  
Tomáš Vrška

A hypothesis was verified that forest floor chemistry varies according to position within the windthrow (mound, pit, or control). A parallel assessment was made of differences in the chemistry of horizons and their forms. A total number of 1720 windthrows were studied in the fir–beech primeval forest in the flysch zone of the Western Carpathians. A total of 100 samples were taken on three positions from the following horizons and their forms (in brackets): litter, fermented (amphigenous, zoogenous, or mycogenous), humification (unresolved, zoogenous, residues, or humic), and mineral. A random sampling eliminated the effect of correlation between the horizons and positions. Parameters assessed were Q4/6, HA/FA, C-forms, total N, P, K, and Mg contents, soil reaction, and cation-exchange capacity. The positions exhibited a significant difference in the forest floor chemistry even at a level of horizon forms. The position’s significance decreased with the horizon depth. Organic horizons in the pit, in particular, exhibited the lowest content of total humic substances, fulvic acids, and the lowest colour coefficient values. However, the mineral horizon showed no significant differences between the positions within the windthrow. Compared with other humus types, the decomposing wood mass did not exhibit a different ratio of humic and fulvic acids.


1994 ◽  
Vol 123 (2) ◽  
pp. 247-252 ◽  
Author(s):  
D. Vaughan ◽  
B. G. Ord

SummaryFerrous iron is oxidized and precipitated as iron ochre in field drains. In drainage waters taken from an ochre-producing site near Aberdeen, Scotland in 1987, iron deposition was inhibited by the addition of humic and fulvic acids, which form complexes with Fe(II). The inhibition was dependent on the concentrations of soluble humic materials and the proportion of Fe complexed. Iron deposition in the presence of humic substances is discussed in relation to the amount of the cation which is complexed and its oxidation state.


2015 ◽  
Vol 2 (1) ◽  
pp. 73-78
Author(s):  
A. Fateev ◽  
D. Semenov ◽  
K. Smirnova ◽  
A. Shemet

Soil organic matter is known as an important condition for the mobility of trace elements in soils, their geo- chemical migration and availability to plants. However, various components of soil organic matter have differ- ent effect on these processes due to their signifi cant differences in structure and properties. Aim. To establish the role of humic and fulvic acids in the process of formation of microelement mobility in soils and their accu- mulation in plants. Methods. A model experiment with sand culture was used to investigate the release of trace elements from preparations of humic and fulvic acids and their uptake by oat plants. Results. It was found that among biologically needed elements humic acids are enriched with iron, fulvic acids – with zinc, and copper distribution between these two groups of substances may be characterized as even. These elements have un- equal binding power with components of soil organic matter, as evidenced by their release into the cultivation medium and accumulation in plants. In the composition of fulvic acids zink has the most mobility – up to 95 % of this element is in the form, accessible for plants; the lowest mobility was demonstrated by copper in the composition with humic acids, for which no signifi cant changes in the concentration of mobile forms in the substrate and in the introduction to the test culture were registered. Despite signifi cantly higher iron content in humic acids, the application of fulvic acids in the cultivation medium provides a greater increase in the con- centration of mobile forms of this element. Conclusions. The results confi rm the important role of organic sub- stances of fulvic nature in the formation of zinc and iron mobility in the soil and their accumulation in plants.


2006 ◽  
Vol 3 (2) ◽  
pp. 131 ◽  
Author(s):  
Noel E. Palmer ◽  
John H. Freudenthal ◽  
Ray von Wandruszka

Environmental Context.Reduction of arsenic(v) to arsenic(iii) in the environment is of interest because of the greater toxicity and mobility of the latter. It is important to know to what extent humic materials (which are ubiquitous in soils) can act as abiotic reducing agents, and what factors influence their actions. Abstract.Inorganic arsenates were found to be reduced to arsenite by homogeneous aqueous solutions of several humic and fulvic acids. Because of the concentration dependence of the redox potentials of humics, reduction was shown to be less likely in more concentrated solutions. This was especially true in higher pH ranges, and varied with the type of material used. Ion chromatography, validated by inductively coupled plasma mass spectrometry, was used to speciate arsenic after exposure to aqueous humates and fulvates. Reduction of As(v) proceeded in the 20–60% range, depending on the humic or fulvic acid used. The fraction of arsenate that was reduced initially increased with humic concentration, but leveled off as the reduction potential decreased at higher concentrations. Re-oxidation of As(iii) in humic solutions could be achieved by extended bubbling with air. Reduction capacities of two humates tested, as measured by I2 titration, were found to be significantly different.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Anna Ziolkowska ◽  
Bozena Debska ◽  
Magdalena Banach-Szott

Abstract The aim of the research has been to determine the role of phenolic compounds in the processes of transformations of organic matter in meadow soils, leading to the formation of humic substances. The research has been performed based on the plant material and soil sampled from Europe’s unique complex of permanent grasslands irrigated continuously for 150 years applying the slope-and-flooding system, the Czerskie Meadows. Phenolic compounds were isolated from the plant material samples (hay, sward and roots) and soils (horizon A, AE and Bsv) and from the fraction of humic and fulvic acids. It was found that the contents of phenolic compounds decrease in the following order: hay > sward > roots > A horizon soil > AE horizon soil > Bsv horizon soil > A horizon fulvic acids > AE horizon fulvic acids > Bsv horizon fulvic acids > A horizon fulvic acids > AE horizon fulvic acids > Bsv horizon fulvic acids. A significantly higher share of cinnamyl than vanillyl and syringyl compounds in the extracts of fulvic acids and slightly higher in the hydrolysates of humic acids confirms the effect of the chemical composition of the plant material undergoing decomposition on the properties of the emerging humic substances.


2015 ◽  
Vol 402 (1-2) ◽  
pp. 129-143 ◽  
Author(s):  
Sylwester Smoleń ◽  
Iwona Ledwożyw-Smoleń ◽  
Włodzimierz Sady

2021 ◽  
Vol 340 ◽  
pp. 01001
Author(s):  
Natalya Yudina ◽  
Elizaveta Linkevich ◽  
Anna Saveleva ◽  
Oleg Lomovsky

In the study, a mechanochemical modification of peat was carried out, leading to an increase in the number of functional groups and an increase in the solubility of humic complexes with metals. It was shown that the mechanical activation of peat in the presence of Zn significantly increased the yield of extractable fulvic acids. An analysis of the spectral coefficients showed that humic and fulvic acids extracted from peat were characterized by an increased content of alcohol hydroxyl groups, C–O carbohydrate moieties, and carboxyl groups.


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