scholarly journals Amphiphilic properties of humic substances in soils of the southern Vitim Plateau (Transbaikalia, Eastern Siberia)

2021 ◽  
Vol 908 (1) ◽  
pp. 012034
Author(s):  
E Yu Milkheev ◽  
Yu B Tsybenov
Keyword(s):  
Humic Substances ◽  
Hydrophobic Interactions ◽  
Multicomponent System ◽  
Hydrophobic Interaction Chromatography ◽  
Fulvic Acids ◽  
Eastern Siberia ◽  
Hydrophobic Properties ◽  
Hydrophobic Compounds ◽  
Acid Sample ◽  
Lower Capacity

Abstract Humic substances of soils are considered as a multicomponent system of amphiphilic (exhibiting both hydrophilic and hydrophobic properties) substances. Humic substances from soils of different genesis in the south of the Vitim Plateau (quasigley chernozem – Turbic Chernozem Molliglossic and brown soil – Stagnic Phaeozem Molliglossic) were studied. Using the hydrophobic interaction chromatography on Octyl-Sepharose® CL-4B, we separated a mixture of humic (HAs) and fulvic acids (FAs) due to their different ability to enter into hydrophobic interactions with the gel matrix. A higher percentage of hydrophobic compounds was revealed in HAs of quasigley chernozem, compared to HAs of brown soils, and FAs. The fulvic acid sample showed a lower capacity for hydrophobic interactions than the humic acid sample.

scholarly journals Interactions of hydrophobic metal complexes and their constituents with aquatic humic substances

2007 ◽  
Vol 4 (5) ◽  
pp. 323 ◽  
Author(s):  
Amiel Boullemant ◽  
Jean-Pierre Gagné ◽  
Claude Fortin ◽  
Peter G. C. Campbell
Keyword(s):  
Metal Complexes ◽  
Humic Substances ◽  
Natural Waters ◽  
Hydrophobic Interactions ◽  
Equilibrium Dialysis ◽  
Fulvic Acids ◽  
Suwannee River ◽  
Dissolved Humic Substances ◽  
Ph Range

Environmental context. Lipophilic metal complexes, because they can readily cross biological membranes, are especially bioavailable. However, in natural waters these complexes do not necessarily exist in a free state, i.e. they may bind to the organic matter (humic substances) that is present in natural waters. It follows that the in situ bioavailability of lipophilic metal complexes will tend to be less than that measured in simple laboratory experiments. Abstract. The ability of dissolved humic substances (HS: fulvic and humic acids) to complex cationic metals is well known, but their interactions with neutral lipophilic metal complexes are little understood. In the present study, we have examined the behaviour of two such complexes ( Cd  L 2 0 -->Cd L02: L = DDC = diethyldithiocarbamate, or L = XANT = ethylxanthate) in the presence of Suwannee River Humic and Fulvic acids. Interactions between the neutral complexes and the humic substances were assessed by excitation-emission matrix (EEM) fluorescence spectroscopy at pH 5.5 and 7.0, and by equilibrium dialysis experiments (500 Da cut-off). The EEM measurements were carried out by titrating the humic substances (6.5 mg C L–1) with Cd, in the absence or presence of ligand L (1 µM DDC or 100 µM XANT). Given the very high stability constants for the complexation of cadmium by DDC and XANT and the excess ligand concentration, virtually all (>96%) of the Cd added to the L + HS matrix was calculated to be present as the neutral Cd L 2 0 -->CdL20 complex over the entire pH range tested. For both humic substances, addition of DDC or XANT alone led to shifts in the fluorescence spectra at both pH values, indicating that the DDC– and XANT– anions likely interact by electrostatic or hydrogen bonding within the humic molecules. The subsequent addition of Cd to these L + HS systems resulted in a disproportionately large enhancement of the fluorescence intensities of individual EEM peaks, this fluorescence enhancement being only slightly decreased by the shift from pH 7.0 to 5.5. We interpret this enhancement as evidence that the two neutral complexes associate with the humic substances, presumably by forming ternary complexes (Ln-Cd-HS). Hydrophobic interactions between the humic substances and the neutral complexes may also contribute, but to a lesser extent, as demonstrated by partitioning calculations based on the lipophilicity of the neutral complexes. The association of the neutral complexes with Suwannee River Humic Acid was confirmed by dialysis experiments.

scholarly journals Characterization of Soil Organic Matter Individual Fractions (Fulvic Acids, Humic Acids, and Humins) by Spectroscopic and Electrochemical Techniques in Agricultural Soils

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1067
Author(s):  
Aleksandra Ukalska-Jaruga ◽  
Romualda Bejger ◽  
Guillaume Debaene ◽  
Bożena Smreczak
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Humic Substances ◽  
Humic Acids ◽  
Agricultural Soils ◽  
Fulvic Acids ◽  
Sorption Properties ◽  
Aliphatic Chains

The objective of this paper was to investigate the molecular characterization of soil organic matter fractions (humic substances (HS): fulvic acids-FAs, humic acids-HAs, and humins-HNs), which are the most reactive soil components. A wide spectrum of spectroscopic (UV–VIS and VIS–nearIR), as well as electrochemical (zeta potential, particle size diameter, and polydispersity index), methods were applied to find the relevant differences in the behavior, formation, composition, and sorption properties of HS fractions derived from various soils. Soil material (n = 30) used for the study were sampled from the surface layer (0–30 cm) of agricultural soils. FAs and HAs were isolated by sequential extraction in alkaline and acidic solutions, according to the International Humic Substances Society method, while HNs was determined in the soil residue (after FAs and HAs extraction) by mineral fraction digestion using a 0.1M HCL/0.3M HF mixture and DMSO. Our study showed that significant differences in the molecular structures of FAs, Has, and HNs occurred. Optical analysis confirmed the lower molecular weight of FAs with high amount of lignin-like compounds and the higher weighted aliphatic–aromatic structure of HAs. The HNs were characterized by a very pronounced and strong condensed structure associated with the highest molecular weight. HAs and HNs molecules exhibited an abundance of acidic, phenolic, and amine functional groups at the aromatic ring and aliphatic chains, while FAs mainly showed the presence of methyl, methylene, ethenyl, and carboxyl reactive groups. HS was characterized by high polydispersity related with their structure. FAs were characterized by ellipsoidal shape as being associated to the long aliphatic chains, while HAs and HNs revealed a smaller particle diameter and a more spherical shape caused by the higher intermolecular forcing between the particles. The observed trends directly indicate that individual HS fractions differ in behavior, formation, composition, and sorption properties, which reflects their binding potential to other molecules depending on soil properties resulting from their type. The determined properties of individual HS fractions are presented as averaged characteristics over the examined soils with different physico-chemical properties.

scholarly journals Organic Materials and Their Chemically Extracted Humic and Fulvic Acids as Potential Soil Amendments for Faba Bean Cultivation in Soils with Varying CaCO3 Contents

Horticulturae ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 205
Author(s):  
Ihab M. Farid ◽  
Mohamed A. El-Ghozoli ◽  
Mohamed H. H. Abbas ◽  
Dalia S. El-Atrony ◽  
Hassan H. Abbas ◽  
...  
Keyword(s):  
Humic Substances ◽  
Faba Bean ◽  
Plant Biomass ◽  
Nitrogenase Activity ◽  
Organic Amendments ◽  
Fulvic Acids ◽  
Mineral N ◽  
Randomized Design ◽  
Long Time ◽  
Factor C

Organic amendments are important sources of nutrients that release upon organic matter degradation, yet the stability of these organics in arid and semi-arid regions is relatively low. In contrast, humic substances (HS) are resistant to biodegradation and can keep nutrients in the soil available for the plant over a long time. Combinations between humic substances (HS) and mineral-N fertilizers are assumed to retain higher available nutrients in soils than those recorded for the sole application of either mineral or organic applications. We anticipate, however, that humic substances might not be as efficient as the organics from which they were extracted in increasing NP uptake by plants. To test these assumptions, faba bean was planted in a pot experiment under greenhouse conditions following a complete randomized design while considering three factors: two soils (calcareous and non-calcareous, Factor A), two organics (biogas and compost, Factor B) and combinations of the organics and their extracts (HA or FA) together with complementary doses of mineral-N ((NH4)2SO4) to attain a total rate of 50 kg N ha−1 (the recommended dose for faba bean plants) (Factor C). Results indicated that nitrogenase activity increased significantly due to the application of the used organics. In this respect, compost manure caused higher nitrogenase activity than biogas manure did. Humic substances raised NP-availability and the uptake by plants significantly; however, the values of increase were lower than those that occurred due to the compost or biogas manure. Moreover, the sole application of the used organics recorded the highest increases in plant biomass. Significant correlations were also detected between NP-availability, uptake and plant biomass. This means that HS could probably retain nutrients in available forms for long time periods, yet nutrients released continuously but slowly upon decomposition of organics seemed more important for plant nutrition.

Bioavailability of a nonylphenol isomer in dependence on the association to dissolved humic substances

2004 ◽  
Vol 50 (5) ◽  
pp. 277-283 ◽  
Author(s):  
R. Vinken ◽  
A. Höllrigl-Rosta ◽  
B. Schmidt ◽  
A. Schäffer ◽  
P.F.-X. Corvini
Keyword(s):  
Humic Acid ◽  
Carbon Source ◽  
Humic Substances ◽  
Organic Compounds ◽  
Sole Carbon Source ◽  
Equilibrium Dialysis ◽  
Fulvic Acids ◽  
Degrading Bacterium ◽  
Bacterium Strain ◽  
Dissolved Humic Substances

Humic substances are important environmental components since they represent a very large part of organic compounds on earth. According to many reports, dissolved humic substances are a determinant parameter for the bioavailability of xenobiotic compounds. For the present bioavailability studies, two kinds of dissolved humic substances, a commercially available humic acid and fulvic acids isolated from peat were used. As the relevant xenobiotic, a defined branched nonylphenol isomer, 4(3′,5′-dimethyl-3′-heptyl)-phenol (p353NP) was synthesised according to Friedel-Crafts alkylation. Equilibrium dialysis studies were implemented in order to investigate the association between 14C-labelled p353NP and dissolved humic substances. The biodegradability in the presence of dissolved humic substances was examined in experiments with the nonylphenol degrading bacterium strain Sphingomonas TTNP3 and with p353NP as sole carbon source. The results showed that p353NP-humic acid associates were formed in high amounts, whereas no adducts with fulvic acids occurred. In the degradation studies with Sphingomonas TTNP3, no effects of dissolved humic substances on the bioavailability of p353NP could be observed. It was assumed that the association between nonylphenol and humic acids occurs rapidly and is reversible. Thus, the formation of "labile" complexes did not influence biodegradation rates, which were quite low.

scholarly journals Fertigation of ‘BRS Princesa’ banana with humic substance and saponin-based plant extracts

Revista CERES ◽  
2017 ◽  
Vol 64 (4) ◽  
pp. 392-398
Author(s):  
Diego Magalhães de Melo* ◽  
Eugênio Ferreira Coelho ◽  
Raul Castro Carriello Rosa ◽  
Ana Lucia Borges ◽  
Djalma Barbosa dos Santos ◽  
...  
Keyword(s):  
Humic Substances ◽  
Humic Substance ◽  
Plant Extract ◽  
Plant Extracts ◽  
Block Design ◽  
Fulvic Acids ◽  
Growth And Yield ◽  
Randomized Block Design ◽  
Number Of Leaves ◽  
Banana Cultivar

ABSTRACT The use of humic substances and plant extract has been increasing mainly in organic crop systems without scientific-based recommendations. Research is necessary to evaluate the feasibility and the recommendations of these substances. The objective of this work was to evaluate the effect of humic substances (humic and fulvic acids) applied by fertigation with and without saponin-based plant extracts on growth and yield of ‘BRS Princesa’ banana. The experiment was carried out using the banana cultivar ‘BRS Princesa’, at a spacing of 2.0 × 2.5 m, fertigated by drip irrigation in a Dystric Densic Xantic Ferralsol, at the Recôncavo da Bahia, Brazil. Treatments consisted of five doses of humic substances (0.0; 70; 105; 140, and 210 L ha-1cycle-1) applied with and without a saponin-based plant extract in a randomized block design in split-plot scheme. The following growth variables were evaluated: number of leaves, pseudostem height, pseudostem diameter, and length and width of the third leaf. The number of fruits/hand and hands/bunch, hand and bunch yield, and length and fruit diameter of the second central hand were evaluated during harvest. The doses of humic substances influenced only pseudostem height. Hand yield, as well as fruit length and diameter of ‘BRS Princesa’ banana were higher in plants fertigated with humic substance and plant extract in comparison with plants fertigated with only humic substance.

scholarly journals Influence of humic substances on the landfill leachate biodegradability with a focus on temporal seasonality

2021 ◽  
Author(s):  
Wagner Guadagnin Moravia ◽  
Victor Rezende Moreira ◽  
Yuri Abner Rocha Lebron ◽  
Liséte Celina Lange ◽  
Míriam Cristina Santos Amaral
Keyword(s):  
Humic Substances ◽  
Landfill Leachate ◽  
Fulvic Acids ◽  
Biologic Treatment ◽  
Adequate Treatment ◽  
Tropical Regions ◽  
Treatment Techniques ◽  
Biological Treatments ◽  
Lowry Method ◽  
The Cost

Abstract The high resilience to biological treatments from the landfill leachate is generally associated with the presence of humic substances (HS). The brown color characteristic of this effluent is also related to these substances. Landfill leachate with low biodegradability can make biological treatments unfeasible, which can drive up the cost for the treatment of large leachate volumes. In this context, this research aimed to characterize the leachate in different seasonal periods, and verify the influence of HS species on the biodegradability of the effluent to assist in the selection of adequate treatment techniques. The HS quantification was performed using the modified Lowry method and speciation through fractionation according to the molar masses of the HS species. The tropical regions can be the precursor for the rapid stabilization of biodegradable organic matter. The warmer climate contributed to a reduced BOD/COD ratio (0.03) and the predominance of compounds of lower mass (e.g.: fluvic acids). The tests showed an HS concentration of 26.9% of the total COD in the raw leachate in the rainy season, which increased to 37.3% in the dry season. Approximately 70% of HS species refer to fulvic acids, a fraction identified as having the highest biologic treatment resilience.

Mean residence times and characteristics of humic substances extracted from a Taiwan soil

2001 ◽  
Vol 81 (3) ◽  
pp. 299-307 ◽  
Author(s):  
M C Wang ◽  
S H Chang
Keyword(s):  
Humic Substances ◽  
Soil Profile ◽  
Fulvic Acids ◽  
Spectroscopic Properties ◽  
Residence Times ◽  
Spin Resonance ◽  
Profile Depth ◽  
Mean Residence Times ◽  
High Degree ◽  
C Nmr

Humic substances are well known for their long-term persistence in soil environments. The relationship between the mean residence times (MRT) and characteristics of humic substances extracted from a soil with highorganic matter (OM) content in Taiwan was investigated. The MRTs of the soil organic matter (SOM) and its humic substances extracted from the soil samples taken from three depths (0–20, 40–60, and 70–150 cm) of a soil profile were determined by 14C-dating procedures. Moreover, the humic substances were subjected to elemental analysis and investigation by electron spin resonance (ESR), Fourier transform infrared (FTIR), and solid-state 13C nuclear magnetic resonance (13C NMR) spectroscopies. The ranges of the MRT of fulvic acids (FA) (MW < 1000), FA (MW > 1000), humic acid (HA) (MW > 1000), and humins (MW > 1000) were 143 ± 110 to 1740 ± 60, 213 ± 120 to 1690 ± 200, 253 ± 60 to 2200 ± 40, and 293 ± 40 to 2173 ± 70 yr, respectively. The higher standard deviations of the means of determined MRTs of FA (MW < 1000) and FAs (MW > 1000) may be due to their lability. Further, the MRTs of the FAs (MW < 1000), FAs (MW > 1000), HAs (MW > 1000), and humins (MW > 1000) increased with increasing soil profile depth, indicating the slow biological and chemical degradations of humic substances in the deeper layers. The elemental composition and spectroscopic properties of FTIR, 13C NMR, and ESR of humic substances did not change significantly with their MRTs. The MRTs in the range observed in this study were apparently long enough to render humic substances a high degree of chemical stability. Key words: Humic substances, mean residence times, ESR, FTIR, 13C NMR, humin

EFFECT OF HUMIC AND FULVIC ACIDS ON MICROBIAL GROWTH

2021 ◽  
Author(s):  
Milanka Radulovic ◽  
◽  
Svetlana Mitrovski
Keyword(s):  
Humic Acid ◽  
Humic Substances ◽  
Minimal Medium ◽  
Microbial Growth ◽  
Growth Curves ◽  
Fulvic Acids ◽  
Humic And Fulvic Acids ◽  
Staphyloccocus Aureus ◽  
Low Ionic Strength ◽  
Strength Medium

Peat is a natural substrate for growth of microorganisms because it is rich in compounds that microorganisms can use as sources of carbon, nitrogen and growth factors. Peat originating from Vlasina lake in Eastern Serbia is especially rich in organic matter. The content of humic substances (humic acid, fulvic acid and humine) is almost twice that found in other peat-rich regions of similar origin and geochemical age. Humic and fluvic acids are known to promote microbial growth. In this work, humic and fulvic acids were first extracted from Vlasina lake peat and then added to minimal medium (synthetic, low ionic strength medium). The humic substances were added separately and combined in a 1:1 ratio by mass to study their individual and combined effect on microbial growth of Escherichia coli ATCC 25922 (Gr–), Staphyloccocus aureus (Gr+) i Aureobasidium pullulans, strain CH-1. The microbial growth was measured microspectrophotometrically over a 24-hour period and growth curves were obtained for a range of acid concentrations between 25 µg cm-3 and 100 µg cm-3. It was found that both humic and fulvic acids promote the growth of all three microorganisms by up to a maximum of 40%-80% the extent of which varied with the concentration of the acid and the identity of the microorganism. In general, humic acid was found to result in higher microbial growth (at highest concentrations, up to ~80% for all three microbial species).

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