Development of an ICP−IDMS Method for Dissolved Organic Carbon Determinations and Its Application to Chromatographic Fractions of Heavy Metal Complexes with Humic Substances

1998 ◽  
Vol 70 (10) ◽  
pp. 2038-2043 ◽  
Author(s):  
Jochen Vogl ◽  
Klaus G. Heumann
Keyword(s):  
Heavy Metal ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Metal Complexes ◽  
Humic Substances

Humic Colloid Generation of Transuranic Elements in Groundwater and Their Migration Behaviour

1986 ◽  
Vol 84 ◽  
Author(s):  
J.I. Kim ◽  
G. Buckau ◽  
W. Zhuang
Keyword(s):  
Heavy Metal ◽  
Humic Acid ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Metal Ions ◽  
Fulvic Acid ◽  
Photoacoustic Spectroscopy ◽  
Heavy Metal Ions ◽  
Colloidal Form ◽  
Doc Concentration

AbstractThe generation of humic colloids of Am(III) has been investigated in Gorleben groundwaters containing different amounts of humic substances. Dissolved organic carbon (DOC) in these groundwaters consists mainly of humic acid and fulvic acid, which is present in a colloidal form through aggregation with trace heavy metal ions of groundwater constituents. Concentrations of these heavy metal ions are proportional to the DOC concentration. The generation of Am(III) pseudocolloids through geochemical interactions with humic colloids in different groundwaters is quantified by ultrafiltration as well as ultracentrifugation by the aid of radiometric concentration measurements. The speciation of dissolved Am(III) species in groundwaters is carried out by laser induced photoacoustic spectroscopy (LPAS).

Contributions of humic substances to the dissolved organic carbon pool in wetlands from different climates

Chemosphere ◽  
2012 ◽  
Vol 88 (10) ◽  
pp. 1265-1268 ◽  
Author(s):  
Akira Watanabe ◽  
Kunio Moroi ◽  
Hiromu Sato ◽  
Kiyoshi Tsutsuki ◽  
Nagamitsu Maie ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Humic Substances ◽  
Carbon Pool ◽  
Organic Carbon Pool ◽  
Different Climates

Sensors for Detecting Humic Substances and Heavy Metal Complexes in Waters

2006 ◽  
Author(s):  
A. Firmino ◽  
C.E. Borato ◽  
F.L. Leite ◽  
O.N. Oliveira ◽  
W.T.L. Silva ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Complexes ◽  
Humic Substances

scholarly journals New possibility for characterization of dissociation behaviour of supramolecular electrolytes: results obtained for the International Humic Substances Society standard and reference samples by coulometry

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Martina Klučáková
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Humic Substances ◽  
Functional Groups ◽  
Dissociation Constants ◽  
Fulvic Acids ◽  
Molecular Organization ◽  
Humic And Fulvic Acids ◽  
Acid Base ◽  
Reference Samples

Abstract Background Humic substances can be considered as polyelectrolytes with supramolecular character and complicated behaviour in water environment. The fractions of humic substances dissolved in water are the most active ones and determinative for their functioning in nature, where the proton-binding and dissociation ability play a crucial role. The dissociation behaviour of humic and fulvic acids can be affected by different circumstances including their concentration which is directly connected with the molecular organization of humic particles in solution and the accessibility of their ionizable functional groups. This study is focused just on these active fractions and their dissociation behaviour in the dependence on their content in studied system. Results Standards and reference samples of International Humic Substances Society were used. Flow-through coulometry was used to determine the total content of acidic functional groups in fulvic solutions and humic leachates. The amount of dissociated acidic groups was determined on the basis of potentiometry. Several differences between the behaviour of humic and fulvic acids were found. While whole samples of fulvic acids including the weakest functional groups were analysed, only the active dissolved humic fractions containing stronger acidic functional groups were characterized. The fractions containing higher amounts of the weakest functional groups remained insoluble. The dissociation degree of fulvic acids decreased with their increasing content, but a maximum on its concentration dependence obtained for humic acids was observed. Conclusions Two different values of dissociation constants were determined for each sample. The first was determined on the basis of the extrapolation of infinite dilution, second was determined as their average value in the region of high concentrations in which it was constant. Obtained values characterize the functioning of dissolved humic substances from point of view of their dissociation ability. The results obtained by this approach can help to predict the acid–base behaviour of dissolved organic carbon in soil and generally in nature. The acid–base behaviour of dissolved organic carbon depends on its ratio to water. It behaves differently in soil which is dry and in soil which is wet or saturated by water.

Microbial Activity in Sanitary Landfills–A Possible Source of the Humic Substances in Groundwater?

1988 ◽  
Vol 20 (3) ◽  
pp. 55-59 ◽  
Author(s):  
Z. Filip ◽  
R. Smed-Hildmann
Keyword(s):  
Humic Acid ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Humic Substances ◽  
Spectral Characteristics ◽  
Organic Substances ◽  
Groundwater Aquifers ◽  
Sanitary Landfills ◽  
Municipal Refuse ◽  
Indigenous Microflora

Humic substances account for the main part of the dissolved organic carbon in groundwater. Since groundwater aquifers located near to sanitary landfills usually contain higher concentrations of dissolved organic carbon, we made experiments in the laboratory to determine whether humic substances can be formed from simple non-humified organic substances by a complex micro-flora of municipal refuse. In liquid cultures incubated for two months humic substances were produced, especially when casein or starch was added. The highest amounts of humic acid-like substances were yielded from cultures inoculated with the indigenous microflora from a rotted (aerobic) landfill. Minor yields were obtained when the inoculum originated from a compacted (anaerobic) landfill or from a five years old landfill containing refuse and sewage sludge. Spectral characteristics indicated some similarities but also differences in the UV and visible regions between the newly formed humic acids and a humic acid from groundwater.

Characterization of organic matter content of Hungarian agricultural soils

2012 ◽  
Vol 60 (4) ◽  
pp. 357-366
Author(s):  
M. Nadi ◽  
E. Sedaghati ◽  
G. Füleky
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Humic Substances ◽  
Agricultural Soils ◽  
Organic Matter Content ◽  
Extraction Process ◽  
Matter Content ◽  
Soil Samples ◽  
Hot Water ◽  
Uv Absorbance

Humic substances have proved to be very important fractions in soils, playing a key role especially in agricultural soil and influencing chemical and physical soil properties. Spectroscopic methods are widely used to identify the quality of soil humic substances. In this study, 16 soil samples were selected from the Soil Bank of the Soil Science Laboratory at Szent István University, Gödöllő. The samples were extracted using the Hot Water Percolation (HWP) method and the amount of dissolved organic carbon (DOC) in each fraction was measured. The kinetics of the DOC extraction process with the HWP method was estimated. The Ultraviolet Visible (UV-VIS) technique was used to characterize the properties of HWP-dissolved organic carbon (HWP-DOC), measuring absorbance at 200–700 nm. Among the humification parameters, the absorbance ratios at 254 and 365 nm (E2/E3) and 465 and 665 nm (E4/E6), the specific UV absorbance (SUVA) and the UV absorbance ratio index (URI) were estimated. The K factor (humus stability coefficient) and E2/E3 and E4/E6 in NaOH and NaF extracts were also measured. The properties of HWP-DOC were similar in most of the soil samples. There was a good correlation between the content of HWP-DOC and the absorbance at 254 nm. URI, SUVA, E2/E3 and E4/E6 indicated that most of the HWP-DOC in the samples consisted of fulvic acid components with greater activity, simpler structure and low molecular weight.

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