scholarly journals Humic Substances: Its Toxicology, Chemistry and Biology Associated with Soil, Plants and Environment

2021 ◽  
Author(s):  
Rajneesh Kumar Gautam ◽  
Dimuth Navaratna ◽  
Shobha Muthukumaran ◽  
Amarendra Singh ◽  
Islamuddin ◽  
...  
Keyword(s):  
Organic Matter ◽  
Humic Substances ◽  
Natural Organic Matter ◽  
Chemical Study ◽  
Fulvic Acids ◽  
Molecular Structures ◽  
Terrestrial Organic Matter ◽  
Humic Compounds ◽  
Physico Chemical ◽  
Molecular Aspects

In recent decades, scientists in different disciplines have been increasingly concerned about the fate of natural organic matter, and in particular of humic substances (HS). The term humic substances (HS) incorporates refractory autochthonous and terrestrial organic matter in the soil and aquatic ecosystem, and are one of the key fractions of natural organic matter. These substances are important chelators of trace elements constituting complex class of molecular structures that occur naturally, consisting of aggregation and assembly processes in which biomolecules derived from plant and animal residues are gradually transformed through biotic and abiotic tracts. Since these organic compounds are bound by or linked with soil mineral fractions, they must be physically or chemically separated from the inorganic components by an extraction method before their physico-chemical study. This chapter focuses on the chemo-toxicological, molecular aspects of humic compounds and their derivatives such as humins, fulvic acids, humic acids etc., with their agricultural, biomedical, environmental and biochemical applications. In addition to studying their impact on plant physiology and soil microstructure to expand our understanding about humic compounds.

Characterization of natural organic matter from four Victorian freshwater systems

1991 ◽  
Vol 42 (6) ◽  
pp. 675 ◽  
Author(s):  
GM Day ◽  
R Beckett ◽  
BT Hart ◽  
ID McKelvie
Keyword(s):  
Organic Matter ◽  
Microbial Community ◽  
Humic Acid ◽  
Humic Substances ◽  
Natural Organic Matter ◽  
Residence Time ◽  
Contact Time ◽  
Fulvic Acids ◽  
Humic Fraction

The natural organic matter (NOM) from three streams (Redwater Creek, Slip Creek, Myrtle Creek) and one small lake (the Inkpot) in Victoria, Australia, was fractionated by a simplified version of Leenheer's method in which the NOM is separated into two fractions-hydrophobic acid (HFo-A) compounds and total hydrophilic (HE-T) compounds-on the basis of association with XAD-8 resin. Subsequently, the HFo-A fraction was further separated into humic acid and fulvic acid fractions. One sample (Redwater Creek) was also separated into six different fractions by the full Leenheer scheme. Considerable variation was found in the ratio of humic substances (or the HFo-A fraction) to nonhumic substances (or the HFi-T fraction) between the four samples, with ratios ranging from a high of 77:23% for the Inkpot to a low of 20:80% for Slip Creek. Samples with higher NOM concentrations had higher percentages of humic substances. The major differences in the proportions of humic to nonhumic compounds observed for Slip Creek (20:80%) and Myrtle Creek (52:48%) support the hypothesis that the residence time of the water in the catchment (or, more specifically, the contact time between this water and the sediments, soil, vegetation and microbial community) may control the concentration and nature of aquatic NOM. Within the HFo-A, or humic fraction, the ratio of fulvic acids to humic acids was fairly constant for each of the four water samples investigated, being dominated (>80%) by fulvic acids.

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 Using water hyacinth (Eichhornia crassipes) biomass and humic substances to produce urea-based multi-coated slow release fertilizer

Cellulose ◽  
2021 ◽  
Author(s):  
Iris Amanda A. Silva ◽  
Osmir Fabiano L. de Macedo ◽  
Graziele C. Cunha ◽  
Rhayza Victoria Matos Oliveira ◽  
Luciane P. C. Romão
Keyword(s):  
Organic Matter ◽  
Humic Substances ◽  
Natural Organic Matter ◽  
Nitrogen Fertilization ◽  
Water Hyacinth ◽  
Eichhornia Crassipes ◽  
Slow Release ◽  
Leaching Tests ◽  
Slow Release Fertilizer ◽  
Atmosphere System

AbstractUrea-based multi-coated slow release fertilizer was produced using water hyacinth, humic substances, and chitosan, with water rich in natural organic matter as a solvent. Elemental analysis showed that the nitrogen content of the fertilizer (FERT) was around 20%. Swelling tests demonstrated the effectiveness of the water hyacinth crosslinker, which reduced the water permeability of the material. Leaching tests showed that FERT released a very low concentration of ammonium (0.82 mg L−1), compared to the amount released from urea (43.1 mg L−1). No nitrate leaching was observed for FERT, while urea leached 13.1 mg L−1 of nitrate. In water and soil, FERT showed maximum releases after 30 and 40 days, respectively, while urea reached maxima in just 2 and 5 days, respectively. The results demonstrated the promising ability of FERT to reduce nitrogen losses, as well as to minimize environmental impacts in the soil–plant-atmosphere system and to improve the efficiency of nitrogen fertilization. Graphic abstract

scholarly journals Stability of Fe-oxide nanoparticles coated with natural organic matter under relevant environmental conditions

2014 ◽  
Vol 70 (12) ◽  
pp. 2040-2046 ◽  
Author(s):  
L. Chekli ◽  
S. Phuntsho ◽  
L. D. Tijing ◽  
J. L. Zhou ◽  
J.-H. Kim ◽  
...  
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Environmental Conditions ◽  
Divalent Cations ◽  
Oxide Nanoparticles ◽  
Fe Oxide ◽  
Coated Nanoparticles ◽  
Aggregation Behaviour ◽  
Physico Chemical ◽  
The Stability

Manufactured nanoparticles (MNPs) are increasingly released into the environment and thus research on their fate and behaviour in complex environmental samples is urgently needed. The fate of MNPs in the aquatic environment will mainly depend on the physico-chemical characteristics of the medium. The presence and concentration of natural organic matter (NOM) will play a significant role on the stability of MNPs by either decreasing or exacerbating the aggregation phenomenon. In this study, we firstly investigated the effect of NOM concentration on the aggregation behaviour of manufactured Fe-oxide nanoparticles. Then, the stability of the coated nanoparticles was assessed under relevant environmental conditions. Flow field-flow fractionation, an emerging method which is gaining popularity in the field of nanotechnology, has been employed and results have been compared to another size-measurement technique to provide increased confidence in the outcomes. Results showed enhanced stability when the nanoparticles are coated with NOM, which was due to electrosteric stabilisation. However, the presence of divalent cations, even at low concentration (i.e. less than 1 mM) was found to induce aggregation of NOM-coated nanoparticles via bridging mechanisms between NOM and Ca2+.

Structural characterization of soil organic matter individual fractions (fulvic acids, humic acids and humins) in relation to potential sorption of organic contaminants 

2021 ◽  
Author(s):  
Aleksandra Ukalska-Jaruga ◽  
Romualda Bejger ◽  
Guillaume Debaene ◽  
Bozena Smreczak
Keyword(s):  
Molecular Weight ◽  
Humic Substances ◽  
Organic Contaminants ◽  
Particle Diameter ◽  
Fulvic Acids ◽  
Molecular Structures ◽  
Sorption Properties ◽  
Binding Potential ◽  
Aliphatic Chains

<p>The objective of this paper was to investigate the molecular characterization of individual humic substances ( fulvic acids-FAs, humic ascids-HAs, and humins-HNs), which are the most reactive soil components and exhibit high sorption capacity in relation to various groups of organic contaminants. A wide spectrum of spectroscopic (UV-VIS, VIS-nearIR), as well as electrochemical (zeta potential, particle size diameter, polidyspersity index), methods were applied to find the relevant differences in the behavior, formation, composition and sorption properties of HS fractions derived from various mineral soils.</p><p>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.</p><p>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.  </p><p>The observed trends directly indicate that individual HS fractions differ in behavior, formation, composition and sorption properties, which reflects their binding potential to different group of organic contaminants, but the general properties of individual fractions are similar and do not depend on the type of soil.</p><p><em>Acknowledgement: The studies were supported from the National Science Centre project No. 2018/29/N/ST10/01320 “Analysis of the fractional composition and sorption properties of humic substances in relation to various groups of organic contaminants”</em></p>

scholarly journals Sub-annual fluorescence measurements of coral skeleton: relationship between skeletal luminescence and terrestrial humic-like substances

Coral Reefs ◽  
2020 ◽  
Vol 39 (5) ◽  
pp. 1257-1272 ◽  
Author(s):  
Nikita Kaushal ◽  
Liudongqing Yang ◽  
Jani T. I. Tanzil ◽  
Jen Nie Lee ◽  
Nathalie F. Goodkin ◽  
...  
Keyword(s):  
Organic Matter ◽  
Humic Substances ◽  
Terrestrial Organic Matter ◽  
Organic Matter Sources ◽  
Hydrological Variability ◽  
Marine Organic Matter ◽  
Fluorescence Measurements ◽  
Organic Carbon Fluxes ◽  
Annual Resolution ◽  
Coral Powder

Abstract Some massive coral core slices reveal luminescent bands under ultraviolet light, which have been attributed to terrestrial humic acids in the skeleton. Coral luminescence has therefore been used to reconstruct past climate and hydrological variability. However, it has remained unresolved how closely coral luminescence at sub-annual resolution is related to terrestrial humic acid concentrations. This study presents a solution-based fluorescence method to quantify terrestrial humic substances in less than 4 mg of coral powder. The results show that in corals from Malaysia and Singapore, the luminescence green-to-blue ratio is correlated with skeletal concentrations of terrestrial humic substances (R2 > 0.40, p < 0.001) at two sites that are exposed to terrestrial dissolved organic matter from peatlands on Sumatra. In contrast, coral cores from two other sites located far from major terrestrial organic matter sources show lower green-to-blue values and no convincing correlation with fluorescence intensity of terrestrial humic substances in the skeleton. Abiogenic aragonite precipitation experiments with both terrestrial and marine organic matter sources confirmed that terrestrial humic substances are readily incorporated into aragonite, but not fluorescent organic matter from marine sources. The results of this study suggest that in coral cores with high luminescence green-to-blue ratios (> 0.6) and large downcore variability (range of ≥ 0.05), the green-to-blue ratio is strongly linked to variation in terrestrial humic substances. Coral cores therefore have the potential to reconstruct past variation in terrigenous dissolved organic carbon fluxes.

scholarly journals Fouling analysis of polysulfone ultrafiltration membranes used for drinking water treatment

2011 ◽  
Vol 11 (6) ◽  
pp. 668-674 ◽  
Author(s):  
B. Q. Zhao ◽  
C. P. Huang ◽  
S. Y. Chen ◽  
D. S. Wang ◽  
T. Li ◽  
...  
Keyword(s):  
Drinking Water ◽  
Organic Matter ◽  
Water Treatment ◽  
Fulvic Acid ◽  
Humic Substances ◽  
Natural Organic Matter ◽  
Drinking Water Treatment ◽  
Ultrafiltration Membranes ◽  
Fluorescence Excitation ◽  
Hydrophobic Fraction

Natural organic matter (NOM) plays a significant role in the fouling of ultrafiltration membranes in drinking water treatment processes. For a better understanding of the interaction between fractional components of NOM and polysulfone (PS) ultrafiltration membranes used for drinking water treatment, fouling and especially the physically irreversible fouling of natural organic matter were investigated. Resin fractionation, fluorescence excitation–emission matrix (EEM) spectroscopy, fourier transform infrared spectroscopy (FTIR), contact angle and a scanning electron microscope (SEM) were employed to identify the potential foulants. The results showed that humic acid and fulvic acid of small size were likely to permeate the membrane, while the hydrophobic fraction of humic and fulvic acid and aromatic proteins tended to be rejected and retained. Organic compounds such as proteins, humic substances, and polysaccharide-like materials, were all detected in the fouling layer. The physically irreversible fouling of the PS membrane seemed to be mainly attributed to the hydrophobic fraction of humic substances.

Proton-binding study of standard and reference fulvic acids, humic acids, and natural organic matter

2003 ◽  
Vol 67 (1) ◽  
pp. 85-96 ◽  
Author(s):  
Jason D Ritchie ◽  
E.Michael Perdue
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Humic Acids ◽  
Fulvic Acids ◽  
Binding Study ◽  
Proton Binding

The role of humic substances in chromium sorption onto natural organic matter (peat)

Chemosphere ◽  
2006 ◽  
Vol 63 (11) ◽  
pp. 1974-1982 ◽  
Author(s):  
J. Kyziol ◽  
I. Twardowska ◽  
Ph. Schmitt-Kopplin
Keyword(s):  
Organic Matter ◽  
Humic Substances ◽  
Natural Organic Matter
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