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.

Characterization of dissolved organic matter (DOM) extracted from soils by hot water percolation (HWP)

2010 ◽  
Vol 59 (1) ◽  
pp. 99-108 ◽  
Author(s):  
M. Takács ◽  
Gy. Füleky
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Natural Organic Matter ◽  
Extraction Methods ◽  
Soil Samples ◽  
Hot Water ◽  
Soil Extracts ◽  
Water Percolation ◽  
Soil Humic Acid

The Hot Water Percolation (HWP) technique for preparing soil extracts has several advantages: it is easily carried out, fast, and several parameters can be measured from the same solution. The object of this study was to examine the possible use of HWP extracts for the characterization of soil organic matter. The HPLC-SEC chromatograms, UV-VIS and fluorescence properties of the HWP extracts were studied and the results were compared with those of the International Humic Substances Society (IHSS) Soil Humic Acid (HA), IHSS Soil Fulvic Acid (FA) and IHSS Suwannee Natural Organic Matter (NOM) standards as well as their HA counterparts isolated by traditional extraction methods from the original soil samples. The DOM of the HWP solution is probably a mixture of organic materials, which have some characteristics similar to the Soil FA fractions and NOM. The HWP extracted organic material can be studied and characterized using simple techniques, like UV-VIS and fluorescence spectroscopy.

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 Molecular characterization of an end-residue of humeomics applied to a soil humic acid

RSC Advances ◽  
2014 ◽  
Vol 4 (45) ◽  
pp. 23658-23665 ◽  
Author(s):  
A. Nebbioso ◽  
A. Piccolo ◽  
M. Lamshöft ◽  
M. Spiteller
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Molecular Characterization ◽  
Natural Organic Matter ◽  
Molecular Composition ◽  
Chemical Fractionation ◽  
Soil Humic Acid

Humeomics encompasses step-wise chemical fractionation and instrumental determination to fully characterize the heterogeneous molecular composition of natural organic matter.

scholarly journals Development of methods for the separation and characterization of natural organic matter in dam water

2014 ◽  
Author(s):  
◽  
Pinkie Sobantu
Keyword(s):  
Molecular Weight ◽  
Humic Acid ◽  
Fulvic Acid ◽  
Humic Substances ◽  
Water Samples ◽  
Fulvic Acids ◽  
Hydroxyl Groups ◽  
Humic And Fulvic Acids ◽  
Vaal Dam

This project arose out the need for a simple method to analyse NOM on a routine basis. Water samples were obtained from the Vaal dam, which is one of the dams used by a hydroelectric power station. Analysis was preceded by separation of NOM into the humic and non-humic portions. The humic portion was separated into two fractions by employing a non-ionic resin (DAX-8) to separate humic acid from fulvic acid. High performance size exclusion chromatography (HPSEC), equipped with an Ultraviolet( UV) detector and an Evaporative Light Scattering (ELS) detector connected in series, was used to obtain molecular weight distribution information and the concentration levels of the two acids. Mixed standards of polyethylene oxide/glycol were employed to calibrate the selected column. Suwanee River humic acid standard was used as a certified reference material. The molecular weight distributions (MWDs) of the isolated fractions of humic and fulvic acids were determined with ELSD detection as weight-average (Mw), number-average (Mn) and polydispersity (ρ) of individual NOM fractions. The Mw/Mn ratio was found to be less than 1.5 in all the fractions, indicating that they have a low and narrow size fraction. An increase in Mn and Mw values, with increasing wavelength for all three humic substances (HS) examined was observed. The HS, isolated from the dam water, was found to be about the same molecular weight as the International Humic Acid Standard (IIHSS). For the fulvic acid standard, the molecular weight was estimated to be around 7500 Da. Characterization of NOM was done to assist in the identification of the species present in the water. FTIR-ATR was used to as a characterization tool to identify the functional groups in the structure of the humic and fulvic acid respectively present in the Vaal Dam. Analysis of the infrared (IR) spectra indicated that the humic acids of the Vaal dam have phenolic hydroxyl groups, hydroxyl groups, conjugated double bond of aromatic family (C=C), and free carboxyl groups. The isolation method has proved to be applicable and reliable for dam water samples and showed to successfully separate the humic substances from water and further separate the humic substances into its hydrophobic acids, namely, humic and fulvic acids. It can be concluded that the Eskom Vaal dam composes of humic substance which shows that the technique alone gives a very good indication of the characteristics of water. The HPSEC method used, equipped with UV and ELSD was able to identify the molecular weight range of NOM present in source water as it confirmed that the Eskom Vaal dam contains humic substances as humic acid and fulvic acid and these pose a health concern as they can form disinfectant byproducts in the course of water treatment with chemicals. FTIR characterization was successful as important functional groups were clearly assigned. Lastly, the use of the TOC and DOC values to calculate SUVA was also a good tool to indicate the organic content in water. It is recommended to use larger amounts of water must be processed to obtain useful quantities of the humic and fulvic acid fractions.

The characterization of the humic complexes of soil organic matter

1947 ◽  
Vol 37 (2) ◽  
pp. 132-138 ◽  
Author(s):  
W. G. C. Forsyth
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Dilute Acid ◽  
Humic Material ◽  
Humic Compound ◽  
Qualitative Characters ◽  
Hydrolysis Of ◽  
Alkali Fractionation ◽  
Humic Fraction

1. During the course of the alkali fractionation and the preparation of the humic precipitates, the qualitative characters of the fractions were followed by employing a standard hydrolysis with dilute acid. Humic acid itself was shown to be unhydrolysed by this reagent, and, therefore, the extent of hydrolysis of a humic fraction can be used as a criterion of purity.2. Studies on the fractionation of the humic precipitate with aqueous, anhydrous, and alcoholic bases, led to the following conclusions:(a) The humic precipitate as normally prepared i s always a mixture of true humic acid with varying amounts of co-precipitated material of a non-humic nature.(b) This non-humic material is not an integral part of the humic molecules, it is merely co-precipitated and adsorbed contaminants.(c) The non-humic material is differentiated from the humic acids by the following properties: (i) it is hydrolysable with acid; (ii) it does not give the characteristic nitro-humic compound on nitration.

scholarly journals Characterization of wastewater from landfills - amount and type of humic substances extracted from leachate

2019 ◽  
Vol 80 ◽  
pp. 03002
Author(s):  
Maria Elisabete Silva ◽  
Marlene Santos ◽  
Isabel Brás
Keyword(s):  
Organic Matter ◽  
Humic Substances ◽  
Functional Groups ◽  
Humic Acids ◽  
Fulvic Acids ◽  
Organic Fertilizers ◽  
Structural Composition ◽  
Carboxylic Groups ◽  
Humification Degree

This study aimed to characterize the humic substances (HS) extracted from landfills wastewater – leachates, with different ages of exploration. To reach the objective it was applied spectroscopy techniques, UV-Vis and FTIR spectra, as well as the ratio between the absorbance analysed. First, the HS were extracted, then fractionated in fulvic acids (FA) and humic acids (HA) and it was evaluated the phytotoxicity. HS content in the leachates were higher than the typical values found in the natural aquatic humic sources. It has been identified that the leachate HS, HA and FA aromatic fractions increased with the increase of the landfilling age, suggesting that the degree of humification increased with the landfilling age. All the HS showed a high aromaticity and humification degree. The HS extracts irrespective of their source presents similar structural composition. The functional groups found are in agreement with the literature: phenols, alcohols, carboxylic groups, aliphatic structures, among others. It was found that HA are mainly organic matter with a higher aromatic degree than FA. The HS and HA showed absence of phytotoxicity, testing by germination index, suggesting that may be used to produce liquid organic fertilizers.

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.

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

Effects of Natural Organic Matter on TCE Removal in Groundwater by Zero-Valent Iron: Batch Study

2013 ◽  
Vol 807-809 ◽  
pp. 486-489
Author(s):  
Tong Zhou Liu ◽  
Pin Hua Rao
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Natural Organic Matter ◽  
Early Stage ◽  
Organic Contaminant ◽  
Zero Valent Iron ◽  
Contaminant Removal ◽  
Inhibitory Effects ◽  
Batch Study

An investigation on the effects of humic acid (representing NOM) on TCE (a typical organic contaminant) removal by Fe0in batch settings was carried out. Inhibitory effects of humic acid on Fe0towards TCE removal were observed. At early stage of the experiments, humic acid might partition with TCE, and the adsorption or deposition of humic acid onto Fe0surface would further facilitated TCE immobilization. Once the reduction reactive sites on Fe0surfaces were covered by accumulated humic acid and the partition of TCE to humic acid became saturated, TCE removal in Fe0was observed retarded.

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