CHEMISTRY OF HUMIC SUBSTANCES EXTRACTED FROM AN ARCTIC SOIL

1975 ◽  
Vol 55 (2) ◽  
pp. 93-103 ◽  
Author(s):  
M. SCHNITZER ◽  
E. VENDETTE
Keyword(s):  
Humic Acid ◽  
Structural Information ◽  
Degradation Products ◽  
Cupric Oxide ◽  
Fulvic Acids ◽  
Climatic Conditions ◽  
Optical Measurements ◽  
The Arctic ◽  
Humic And Fulvic Acids ◽  
Near Surface

A humic and a fulvic acid, extracted from the Ahb horizon of an earth hummock occurring on an Alpine Tundra (Brunic Turbic Cryosol) in the northern part of the Mackenzie river in the Northwest Territories, were characterized by elementary and functional group analyses and by optical measurements. To obtain more detailed structural information, the humic acid, the major organic fraction in the soil extract, was degraded by alkaline permanganate and alkaline cupric oxide oxidation. The degradation products were identified on a gas chromatographic–mass spectrometric–computer system. The analytical characteristics of the Arctic humic and fulvic acids were similar to those reported in the literature for humic and fulvic acids from more moderate climates. However, effects of near-surface permafrost and harsh Arctic climatic conditions manifested themselves in the degradation data. Compared to humic acids from warmer climates, the Arctic humic acid appeared to be poorly developed, exhibiting a low degree of condensation and aromaticity, a low resistance to mild chemical oxidants, yielding only very small amounts of benzenepolycarboxylic acids higher than the di-forms, but relatively large quantities of aliphatic carboxylic acids, especially the n-C16 and n-C18 fatty acids.

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).

scholarly journals THE EFFECTIVENESS OF COMPOST, HUMIC ACID AND PURE FULVATE ON IMPROVEMENT OF ULTISOL SOIL CHEMICAL PROPERTIES

2021 ◽  
pp. 247-254
Author(s):  
Resman ◽  
Sahta Ginting ◽  
Muhammad Tufaila ◽  
Fransiscus Suramas Rembon ◽  
Halim
Keyword(s):  
Humic Acid ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Chemical Properties ◽  
Fulvic Acids ◽  
Exchange Capacity ◽  
Humic And Fulvic Acids ◽  
Total N ◽  
Organic C ◽  
Exchangeable Al

The research aimed to determine the effectiveness of compost containing humic and fulvic acids, and pure humic and fulvic acids in increasing of Ultisol soil chemical properties. The research design used a randomized block design (RBD), consisting of 10 treatments, namely K0: 0 g polybag-1, KO1: 500 g polybag-1, KO2: 500 g polybag-1, KO3: 500 g polybag-1, KO4: 500 g polybag-1, KO5: 500 g polybag-1, KO6: 500 g polybag-1, KO7: 500 g of polybags-1, H: 50 g of polybag-1, A: 500 g polybag-1. Each treatment was repeated three times and obtained 30 treatment units. The results showed that pH H2O (K0: 4.49, KO1: 5.64, KO2: 5.47, KO3: 5.43, KO4: 5.51, KO5: 5.39, KO6: 5.48, KO7: 6.17, H: 5.06, F: 5.15), total-N (%) (K0: 0.13, KO1: 0.17, KO2: 0.18, KO3: 0.30, KO4: 0.25, KO5: 0.24, KO6: 0.29, KO7: 0.36, H: 0.16, F: 0.14), organic-C (%) (K0: 1.85, KO1; 2.30, KO2: 2.24, KO3: 2.33, KO4: 2.62, KO5: 2.25, KO6: 2.27, KO7: 2.95, H: 2.32, F: 2.26) , available-P (%) (K0: 2.75, KO1: 3.24, KO2: 3.16, KO3: 3.27, KO4: 3.57, KO5: 3.31, KO6: 3.37, KO7: 3.89, H: 3.10, F: 3.12), exchangeable-Al (me100g-1) (K0: 2.51, KO1: 2.11, KO2: 2.13, KO3: 2.15, KO4: 1.88, KO5: 2.14, KO6: 2.12, KO7: 1.75, H: 2.16, F: 2.17), base saturation (%) (K0: 30.91, KO1: 63.48, KO2: 52.63, KO3: 53.76, KO4: 56.13, KO5: 54.96, KO6: 56.71, KO7: 65.53, H: 39.11, F: 42.76), cation exchange capacity (me100g-1) (K0: 12.76, KO1: 15.64, KO2: 14.86, KO3: 14.35, KO4: 14.13, KO5: 15.01, KO6: 15.50, KO7: 17.94, H: 14.19, F: 13.73). The combined compost treatment of three types of organic matter (Imperata cylindrica + Rice straw + Glincidia sepium) is more effective in increasing the pH, H2O as 37.42%, total-N as 176.92%, Organic-C as 59.46%, available-P as 41.45%, base saturation as 65.53%, cation exchange capacity as 17.94% and exchangeable -Al, Alreduction as 30.28% of ultisol soil. KEY WORDS: compost, humic acid, fulvate, soil chemical, ultisol

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.

scholarly journals A global end-member approach to derive <i>a</i><sub>CDOM</sub>(440) from near-surface optical measurements

2020 ◽  
Vol 17 (2) ◽  
pp. 475-497 ◽  
Author(s):  
Stanford B. Hooker ◽  
Atsushi Matsuoka ◽  
Raphael M. Kudela ◽  
Youhei Yamashita ◽  
Koji Suzuki ◽  
...  
Keyword(s):  
The United States ◽  
Water Masses ◽  
Global Perspective ◽  
Optical Measurements ◽  
The Arctic ◽  
Quality Data ◽  
Data Set ◽  
Near Surface ◽  
Wave Focusing ◽  
End Members

Abstract. This study establishes an optical inversion scheme for deriving the absorption coefficient of colored (or chromophoric, depending on the literature) dissolved organic material (CDOM) at the 440 nm wavelength, which can be applied to global water masses with near-equal efficacy. The approach uses a ratio of diffuse attenuation coefficient spectral end-members, i.e., a short- and long-wavelength pair. The global perspective is established by sampling “extremely” clear water plus a generalized extent in turbidity and optical properties that each span 3 decades of dynamic range. A unique data set was collected in oceanic, coastal, and inland waters (as shallow as 0.6 m) from the North Pacific Ocean, the Arctic Ocean, Hawaii, Japan, Puerto Rico, and the western coast of the United States. The data were partitioned using subjective categorizations to define a validation quality subset of conservative water masses (i.e., the inflow and outflow of properties constrain the range in the gradient of a constituent) plus 15 subcategories of more complex water masses that were not necessarily evolving conservatively. The dependence on optical complexity was confirmed with an objective methodology based on a cluster analysis technique. The latter defined five distinct classes with validation quality data present in all classes, but which also decreased in percent composition as a function of increasing class number and optical complexity. Four algorithms based on different validation quality end-members were validated with accuracies of 1.2 %–6.2 %, wherein pairs with the largest spectral span were most accurate. Although algorithm accuracy decreased with the inclusion of more subcategories containing nonconservative water masses, changes to the algorithm fit were small when a preponderance of subcategories were included. The high accuracy for all end-member algorithms was the result of data acquisition and data processing improvements, e.g., increased vertical sampling resolution to less than 1 mm (with pressure transducer precision of 0.03–0.08 mm) and a boundary constraint to mitigate wave-focusing effects, respectively. An independent evaluation with a historical database confirmed the consistency of the algorithmic approach and its application to quality assurance, e.g., to flag data outside expected ranges, identify suspect spectra, and objectively determine the in-water extrapolation interval by converging agreement for all applicable end-member algorithms. The legacy data exhibit degraded performance (as 44 % uncertainty) due to a lack of high-quality near-surface observations, especially for clear waters wherein wave-focusing effects are problematic. The novel optical approach allows the in situ estimation of an in-water constituent in keeping with the accuracy obtained in the laboratory.

Uranium(VI) complexation with citric, humic and fulvic acids

2000 ◽  
Vol 88 (6) ◽  
Author(s):  
J.J. Lenhart ◽  
S.E. Cabaniss ◽  
P. MacCarthy ◽  
Bruce D. Honeyman
Keyword(s):  
Humic Acid ◽  
Fulvic Acid ◽  
Ph Dependence ◽  
Fulvic Acids ◽  
Humic And Fulvic Acids ◽  
Binding Model ◽  
High Affinity ◽  
Ph Values ◽  
Mononuclear Complexes ◽  
Large Size

The binding of uranium(VI) by Suwannee River humic and fulvic acids was studied at pH values of 4.0 and 5.0 in 0.10 M NaClOBoth humic and fulvic acids were demonstrated to strongly bind U(VI), with humic acid forming slightly stronger complexes and exhibiting greater pH dependence. Analyses of the data for the humic and fulvic acid systems using the Schubert´s equation previously applied to the citrate system result in an apparent nonintegral number of ligands binding the uranyl ion. Schubert´s method is only appropriate for interpreting mononuclear complexes with integral moles of binding ligands. Thus, a more elaborate binding model was required and the data were interpreted assuming either: (1) a mixture of 1:1 and 1:2 uranyl-ligand complexes or (2) a limited number of high affinity sites forming a 1:1 complex. While both of these modeling approaches are shown to provide excellent fits to the data, the second is deemed more appropriate given the large size of humic and fulvic acid molecules as well as previous results obtained with other metal cations, such as Cu(II).

scholarly journals Isolation of bioactive substance from pure mumie

2014 ◽  
Vol 11 (2) ◽  
pp. 33-35
Author(s):  
T Enkh-Oyun ◽  
Ts Tsatsralt ◽  
J Bayarmaa
Keyword(s):  
Biological Activity ◽  
Humic Acid ◽  
Fulvic Acid ◽  
Fulvic Acids ◽  
Medical Applications ◽  
Asian Countries ◽  
Humic And Fulvic Acids ◽  
Highly Active ◽  
Agricultural Sciences ◽  
Bioactive Substance

Mumie contains humid and fulvic acids. For this study, pure mumie was fractionated into fulvic acid (FA) and humic acid (HA) fractions. Humic and Fulvic Acids are highly active bioregulators, and also they contain both macro- and micro-nutrients needed by human and animal bodies. Mumie is stone like material found in Mongolia at higher altitude, which has various medical applications in Mongolia and other Asian countries [2,3]. In the present study, the biological activity of mumie and its fractions was measured. Fractions were prepared according to the protocol described by I. A. Scheretkin and A.I. Khlebnikov. Both humic and fulvic acids can be obtained with the yields of 5.3% and 18.6 % respectively DOI: http://dx.doi.org/10.5564/mjas.v11i2.213 Mongolian Journal of Agricultural Sciences Vol.11(2) 2013 pp.33-35

scholarly journals Biochar changes in soil based on quantitative and qualitative humus compounds parameters

2018 ◽  
Vol 69 (4) ◽  
pp. 234-242 ◽  
Author(s):  
Monika Mierzwa-Hersztek ◽  
Krzysztof Gondek ◽  
Michał Kopeć ◽  
Aleksandra Ukalska-Jaruga
Keyword(s):  
Humic Acid ◽  
Wheat Straw ◽  
Humic Acids ◽  
Fulvic Acids ◽  
Qualitative Composition ◽  
Humic And Fulvic Acids ◽  
Biochemical Processes ◽  
Alternative Sources ◽  
Higher Doses ◽  
Humic Acid Carbon

Abstract Due to the indisputable significance of humus in many biochemical processes as well as its increasing deficit particularly in light soils, alternative sources of substrates for the reproduction of this constituent should be sought. The aim of this study was to evaluate the effect of the addition of wheat straw and wheat straw biochar (in four rates) on quantitative and qualitative humus parameters. The following properties were determined in soil: pH, organic carbon, total nitrogen, humic and fulvic acids, carbon in the extract, non-hydrolysing carbon and spectrophotometric indexes for solution of humic acids including A2/6, A2/4, A4/6. After applying 1% and 2% additions of biochar to the soil, the Corg soil content significantly increased compared to the same doses of thermally unconverted straw. After 254 days of incubation, the addition of biochar to soil at higher doses, decreased the share of humic acid carbon (CHA, CFA) in the Corg content compared to treatments without organic additions and WS treatment. The nonhydrolysing carbon soil content was significantly increased by treatments with 1% and 2% additions of WSB, which indicates greater stabilisation of humus compounds and, at the same time, lower CO2 emission. Soil humic acids amended by treatment with biochar, especially at 1% and 2% doses, were characterised by lower A2/6 and A2/4 ratios. Recognition of changes that may occur in the quantitative and qualitative composition of soil humus after the application of biochar may in the future be helpful information for determining appropriate biochar dose.

The Chemical Degradation of a Humic Acid

1973 ◽  
Vol 51 (10) ◽  
pp. 1554-1566 ◽  
Author(s):  
Morris Schnitzer ◽  
Maria Ines Ortiz de Serra
Keyword(s):  
Humic Acid ◽  
Chemical Structure ◽  
Degradation Products ◽  
Cupric Oxide ◽  
Chemical Degradation ◽  
Chromatographic Retention ◽  
Sequential Reaction ◽  
The Core ◽  
Preparative Gas Chromatography ◽  
Complex Core

A humic acid (HA) extracted from the A1 horizon of a Brunizem soil was degraded in the unmethylated and methylated form by sequential reaction with oxidants of increasing strength. The HA was first oxidized with alkaline cupric oxide; the products were then further degraded by oxidation with first alkaline KMnO4 and then with H2O2 in alkaline solution. Unmethylated HA was also degraded by Na-amalgam reduction. The degradation products were extracted into organic solvents, methylated, and separated by preparative gas chromatography into relatively pure components which were analyzed by mass spectrometry and micro-i.r. spectrophotometry. A matching of the mass and i.r. spectra and gas chromatographic retention times of the isolated components with those of authentic specimens led to their identification.The experimental data show that the HA contains a relatively easily degradable portion, which comprises guaiacyl and syringyl units and which may be lignin-derived (about 10% of the total weight). This material is degraded by CuO–NaOH oxidation and Na-amalgam reduction. The bulk of the HA structure, however, consists of a more condensed, chemically complex "core", which degrades on more drastic oxidation into complex phenolic and benzenepolycarboxylic acids. It is likely that the "core" originates in part from condensed lignin and in part from products of microbial synthesis. Of the methods investigated, the CuO–NaOH and the KMnO4 oxidation of methylated HA appear most promising for providing information on the chemical structure of the HA.

scholarly journals Importance of Supersaturation in Arctic Black Carbon Simulations

2021 ◽  
pp. 1-42
Author(s):  
Hitoshi Matsui ◽  
Mingxu Liu
Keyword(s):  
Black Carbon ◽  
Threshold Value ◽  
Climatic Conditions ◽  
The Arctic ◽  
Accurate Estimation ◽  
Cloud Droplets ◽  
Near Surface ◽  
Model Simulations ◽  
Microphysical Processes ◽  
Wet Removal

AbstractBlack carbon (BC) aerosol particles in the Arctic heat the atmosphere and snow/ice surfaces and may strengthen the snow-albedo feedback that amplifies Arctic warming. Model simulations of BC concentrations in the Arctic depend strongly on the representation of microphysical processes such as aging, activation, and wet removal. Most BC modeling studies have classified BC particles into hydrophobic BC, which cannot form cloud droplets, and hydrophilic BC, which can form cloud droplets, by assuming a globally constant critical supersaturation threshold value (Sthre), without considering its consistency with cloud maximum supersaturation (Smax). Here we show that it is essential to consider the consistency of Sthre with Smax in global model simulations to reduce uncertainties in near-surface ambient BC concentrations in the Arctic. Previous studies often obtained good agreement between simulated and observed near-surface Arctic BC mass concentrations when a low Sthre (~0.1%) was assumed in their models. However, this Sthre may be too low (activation and wet removal of BC may be underestimated) for the Arctic, because some recent observations and our model simulations suggest that Smax may actually be higher (~0.3%) there. We also demonstrate that spatially varying Sthre values and their consistency with Smax, which previous studies did not consider, must be represented in models for more accurate estimation of BC budget in the Arctic. Because both Smax and BC-aging speed depend on climatic conditions, our findings are an important step toward better simulations of BC impacts on past, present, and future Arctic climates.

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