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1
Sousa, Ricardo Fernandes de, Eliana Paula Fernandes Brasil, Cícero Célio de Figueiredo, and Wilson Mozena Leandro. "SOIL ORGANIC MATTER FRACTIONS IN PRESERVED AND DISTURBED WETLANDS OF THE CERRADO BIOME." Revista Brasileira de Ciência do Solo 39, no. 1 (February 2015): 222–31. http://dx.doi.org/10.1590/01000683rbcs20150048.
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Veredas are humid tropical ecosystems, generally associated to hydromorphic soils and a shallow water table. The soils of these ecosystems are affected by the use of the areas around these veredas. The objective of this study was to determine soil organic matter (SOM) fractions in veredas adjacent to preserved (native savanna) and disturbed environments (agricultural areas and pastures) in the Cerrado biome. Soil samples were collected from the 0-10 and 10-20 cm layers along reference lines drawn along the relief following the upper, middle and lower positions of one of the slopes, in the direction of the draining line of the vereda. The soil analysis determined: total soil OC, total nitrogen and C:N ratio; C and N contents and C:N ratio in particulate and mineral-associated fractions (of SOM); fulvic acids, humic acids and humin fractions and ratio between humic and fulvic acids. The agricultural use around the veredas induced changes in the SOM fractions, more pronounced in the lower part of the slope. In the soil surface of this part, the OC levels in the humic substances and the particulate fraction of SOM, as well as total soil OC were reduced in the vereda next to crop fields.
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Kholodov, V. A., V. A. Ivanov, Ju R. Farkhodov, N. A. Safronova, Z. S. Artemyeva, and N. V. Jaroslavceva. "The Optical Characteristics of Aggregates Organic Matter Fractions in Typical Chernozems." Dokuchaev Soil Bulletin, no. 90 (September 1, 2017): 56–72. http://dx.doi.org/10.19047/0136-1694-2017-90-56-72.
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The consumption specters of organic matter fractions in ultraviolet and visible parts of specter (UV-visible specters) were investigated. The specters of soluted organic matter, as well as labile humic matters and humic matters itselves, which were extracted from small, medium and large aggregates from typical chernozems of long-term experiments were investigated. The samples of undisturbed chernozems, which are annually collected in the annually hayed steppe and from the chernozem with extreme organic matter degradation, were used (variant of long-termed experiment - irreplaceable black fallow since 1964). On the basis of specters obtained the parameters of optical indices SUVA254, E2/E3, E4/E6 were calculated. The highest differences between the aggregates were revealed in extracts of organic matter. The differences were lower for labile humic matters. There were no differences revealed for humic matters between the optical indices for different aggregates of one type of chernozems use. It is shown that all of the three parameters are not changed symbasically. Hence, all of the three parameters should be used for complete spectral characteristic.
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Koopal, Luuk K., Willem H. van Riemsdijk, and David G. Kinniburgh. "Humic matter and contaminants. General aspects and modeling metal ion binding." Pure and Applied Chemistry 73, no. 12 (January 1, 2001): 2005–16. http://dx.doi.org/10.1351/pac200173122005.
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Humic substances are soil and fresh-water components that play an important role in the binding and transport of both organic and inorganic contaminants. Transport of the contaminants due to ground- and fresh-water dynamics is directly related to the risks associated with contaminations. The mobility of soluble humic substances is related to their interaction with soil mineral particles. Some key references for the binding of organic and inorganic contaminants and for the binding of humics to mineral particles are presented. Humic substances also play a role in the analysis of the contaminants in natural waters and with remediation of water or soil polluted with pesticides, heavy metal ions, and radionuclides. These aspects are illustrated with some examples. The problems that are encountered with the modeling of the binding of contaminants to humics and of heavy metal ions in particular are illustrated by considering the nonideal competitive adsorption model (NICA) extended with electrostatic interactions. The NICA-Donnan model gives quite good results for the description of metal ion binding, as is illustrated for metal ion binding to purified peat humic acid (PPHA). Finally, some remarks are made with respect to the use of the NICA-Donnan model in general purpose speciation programs and of simplified versions of the model for predictions under restricted environmental conditions.
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Sánchez-Marín, Paula, Vera I. Slaveykova, and Ricardo Beiras. "Cu and Pb accumulation by the marine diatom Thalassiosira weissflogii in the presence of humic acids." Environmental Chemistry 7, no. 3 (2010): 309. http://dx.doi.org/10.1071/en10015.
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Environmental context.Dissolved organic matter protects aquatic microorganisms from toxic metals by complexing and decreasing the concentration of the biologically reactive species such as free metal ions. However, there are some cases of enhancement of toxic effects when humic acids are present, which is thought to be due to effects of adsorbed humic acids on cell membranes. For a marine diatom, humic acids adsorbed to cell surfaces enhanced metal adsorption, whereas intracellular metal contents decreased as a result of metal binding by humic acids. These findings suggest that the diatom wall, the frustule, presents a barrier against direct effects of adsorbed humic acids on the plasma membrane. Abstract.Metal complexation by dissolved organic matter, as humic acids, is considered to decrease metal bioavailability by lowering the free metal ion concentration. However, dissolved organic matter adsorption on cell surfaces can modify cell membrane properties, which can also influence metal uptake. Copper and lead accumulation and internalisation by the marine diatom Thalassiosira weissflogii were studied in the absence and presence of humic acids, and adsorption of humic acids to cell surfaces was evaluated. Both Pb and Cu intracellular concentrations decreased in the presence of humic acids according to labile metal concentrations measured by anodic stripping voltammetry, whereas total (intracellular plus adsorbed) metal content was enhanced in the presence of humic acids, probably owing to enhanced metal plus humics adsorption to cell surfaces. The results of the present work stress the importance of differentiating between intracellular and total cellular metal in bioavailability studies, and suggest that the silica frustule of diatoms represents a barrier against humic acids effects on cell membranes.
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Frimmel, Fritz H., and Gudrun Abbt-Braun. "Humic matter: basis for life—a plea for humics care." Journal of Soils and Sediments 18, no. 8 (February 6, 2018): 2668–74. http://dx.doi.org/10.1007/s11368-018-1915-5.
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Li, Cuilan, Shuqing Gao, Qiang Gao, Lichun Wang, and Jinjing Zhang. "CHARACTERIZATION OF BULK SOIL HUMIN AND ITS ALKALINE-SOLUBLE AND ALKALINE-INSOLUBLE FRACTIONS." Revista Brasileira de Ciência do Solo 39, no. 1 (February 2015): 120–26. http://dx.doi.org/10.1590/01000683rbcs20150294.
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Humic substances are the major components of soil organic matter. Among the three humic substance components (humic acid, fulvic acid, and humin), humin is the most insoluble in aqueous solution at any pH value and, in turn, the least understood. Humin has poor solubility mainly because it is tightly bonded to inorganic soil colloids. By breaking the linkage between humin and inorganic soil colloids using inorganic or organic solvents, bulk humin can be partially soluble in alkali, enabling a better understanding of the structure and properties of humin. However, the structural relationship between bulk humin and its alkaline-soluble (AS) and alkaline-insoluble (AIS) fractions is still unknown. In this study, we isolated bulk humin from two soils of Northeast China by exhaustive extraction (25 to 28 times) with 0.1 mol L-1 NaOH + 0.1 mol L-1 Na4P2O7, followed by the traditional treatment with 10 % HF-HCl. The isolated bulk humin was then fractionated into AS-humin and AIS-humin by exhaustive extraction (12 to 15 times) with 0.1 mol L-1 NaOH. Elemental analysis and solid-state 13C cross-polarization magic angle spinning nuclear magnetic resonance (13C CPMAS NMR) spectroscopy were used to characterize and compare the chemical structures of bulk humin and its corresponding fractions. The results showed that, regardless of soil types, bulk humin was the most aliphatic and most hydrophobic, AS-humin was the least aliphatic, and AIS-humin was the least alkylated among the three humic components. The results showed that bulk humin and its corresponding AS-humin and AIS-humin fractions are structurally differed from one another, implying that the functions of these humic components in the soil environment differed.
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Deng, Chu Zhou, Song Liu, and Chen Zhong Jia. "Fluorescence Excitation-Emission Spectroscopy for Characterizing Transformation of Dissolved Organic Matter during Landfill Leachate Treatment by Photocatalysis." Advanced Materials Research 726-731 (August 2013): 122–26. http://dx.doi.org/10.4028/www.scientific.net/amr.726-731.122.
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Fluorescence spectroscopy was performed to investigate the composition changes and characteristics of the leachate DOM (dissolved organic matter) during UV-TiO2photocatalytic treatment process. The results showed that fulvic-like, tryptophan-like and humic acids-like matters were the main compounds in leachate. During photocatalytic treatment process, fluorescence spectroscopy of DOM changed considerably. The final products were mainly fulvic-like and tryptophan-like matters. In general, the fluorescence signals of humic acids-like matters had the most significant change, which disappeared entirely after 60 h treatment, implying that humic acids-like matters can be degraded preferentially by photocatalysis. The other notable change was in VIS fulvic-like matters region, which suggested that fulvic-like matters can be significantly degraded. In 72 h photocatalytic effluent, VIS fulvic-like, tryptophan-like and tyrosine-like matters were remained, and the last two matters were the dominant fractions. These results indicated that fulvic-like and humic acids-like matters with macromolecular can be degraded into protein-like matters with micro-molecular by photocatalysis.
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Hatten, Jeff A., and Darlene Zabowski. "Fire severity effects on soil organic matter from a ponderosa pine forest: a laboratory study." International Journal of Wildland Fire 19, no. 5 (2010): 613. http://dx.doi.org/10.1071/wf08048.
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This study investigated the changes in soil organic matter composition by controlling fire severity of laboratory burns on reconstructed surface soil profiles (O, A1 (0–1 cm), and A2 (1–2 cm)). Laboratory burning simulated prescribed burns that would be typical in the understorey of a ponderosa pine forest at low, moderate, and high–moderate severity levels. Soils were analysed for C, N and soil organic matter composition. Soil organic matter was fractionated into humin, humic acid, fulvic acid, soluble non‐humic materials and other hydrophobic compounds. In the O horizon, low‐, moderate‐, and high‐severity treatments consumed an increasing proportion of C and N. Carbon content of the mineral soil was unaffected by burning; however, N content of the A2 horizon decreased after the moderate‐ and high‐severity treatments, likely as a result of N volatilisation. The proportion of non‐soluble material in the O horizon increased with fire severity, whereas the proportion of humin C as total C of the A horizon decreased with fire severity. The decrease in humin was followed by an increase in the other hydrophobic compounds. The higher fire intensity experienced by the burning O horizon created recalcitrant materials while an increase in labile soil organic matter was observed in mineral soil. An increase in labile soil organic matter may cause elevated C and N mineralisation rates often seen after fire.
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Polyakov, Vyacheslav, and Evgeny Abakumov. "Assessments of Organic Carbon Stabilization Using the Spectroscopic Characteristics of Humic Acids Separated from Soils of the Lena River Delta." Separations 8, no. 6 (June 20, 2021): 87. http://dx.doi.org/10.3390/separations8060087.
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In the Arctic zone, where up to 1024 × 1013 kg of organic matter is stored in permafrost-affected soils, soil organic matter consists of about 50% humic substances. Based on the analysis of the molecular composition of humic acids, we assessed the processes of accumulation of the key structural fragments, their transformations and the stabilization rates of carbon pools in soils in general. The landscape of the Lena River delta is the largest storage of stabilized organic matter in the Arctic. There is active accumulation and deposition of a significant amount of soil organic carbon from terrestrial ecosystems in a permafrost state. Under ongoing climate change, carbon emission fluxes into the atmosphere are estimated to be higher than the sequestration and storing of carbon compounds. Thus, investigation of soil organic matter stabilization mechanisms and rates is quite an urgent topic regarding polar soils. For study of molecular elemental composition, humic acids were separated from the soils of the Lena River delta. Key structural fragments of humic matter were identified and quantified by CP/MAS 13C NMR spectroscopy: carboxyl (–COOR); carbonyl (–C=O); CH3–; CH2–; CH-aliphatic; –C-OR alcohols, esters and carbohydrates; and the phenolic (Ar-OH), quinone (Ar = O) and aromatic (Ar–) groups as benchmark Cryosols of the Lena delta river terrestrial ecosystem. Under the conditions of thermodynamic evolutionary selection, during the change between the dry and wet seasons, up to 41% of aromatic and carboxyl fragments accumulated in humic acids. Data obtained showed that three main groups of carbon played the most important role in soil organic matter stabilization, namely C, H-alkyls ((CH2)n/CH/C and CH3), aromatic compounds (C-C/C-H, C-O) and an OCH group (OCH/OCq). The variations of these carbon species’ content in separated humics, with special reference to soil–permafrost organic profiles’ recalcitrance in the current environment, is discussed.
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Lima, Claudivan Costa, Eduardo de Sá Mendonça, and Asunción Roig. "Contribution of humic substances from different composts to the synthesis of humin in a tropical soil." Revista Brasileira de Ciência do Solo 34, no. 4 (August 2010): 1041–48. http://dx.doi.org/10.1590/s0100-06832010000400004.
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The contribution of humic substances of different composts to the synthesis of humin in a tropical soil was evaluated. Increasing doses (0, 13, 26, 52, and 104 Mg ha-1) of five different composts consisting of agroinpowderrial residues were applied to a Red-Yellow Latosol. These composts were chemically characterized and 13C NMR determined and the quantity of the functional alkyl groups of humic acids applied to the soil as compost was estimated. Thirty days after application of the treatments, organic matter samples were collected for fractionation of humic acids (HA), fulvic acids (FA) and humin (HU), from which the ratios HA/FA and (HA + FA)/HU were calculated. The application of the composts based on castor cake resulted in the highest HU levels in the soil; alkyl groups of the HA fraction of the composts were predominant in the organic components added to the HU soil fraction.
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Zhang, Yue Jin, and Juan Wang. "Extraction Methods Study and Structure Analysis of Humic Acid in Surface Soil along Main Transportation Road." Advanced Materials Research 518-523 (May 2012): 201–4. http://dx.doi.org/10.4028/www.scientific.net/amr.518-523.201.
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The five surface soil samples were collected in along zhonghuan road of Jiaxing city. According to different solubility in acid and alkali solution, the soil organic matters were divided into different kinds of components such as fulvic acid, humic acid and Humin. Both humic acid and minerals were extracted by sequence and the images were displayed in assistance of scanning electron microscope. Different extraction time and extraction conditions were optimized and the methods were established in the last. Correlations between organic matter content, pH value and contents of HA were fitted and a linear relationship was found between OM and HA. On the help of SEM, different structure of HA and minerals were found that images of HA were columnar and that of mineral were Massive. It is just the reason that why the OM has great sorption ability than the minerals.
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Wang, M. C., and S. H. Chang. "Mean residence times and characteristics of humic substances extracted from a Taiwan soil." Canadian Journal of Soil Science 81, no. 3 (August 1, 2001): 299–307. http://dx.doi.org/10.4141/s00-068.
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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
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Cardoso, José Alberto Ferreira, Augusto Miguel Nascimento Lima, Tony Jarbas Ferreira Cunha, Marcos Sales Rodrigues, Luis Carlos Hernani, Andre Julio do Amaral, and Manoel Batista de Oliveira Neto. "ORGANIC MATTER FRACTIONS IN A QUARTZIPSAMMENT UNDER CULTIVATION OF IRRIGATED MANGO IN THE LOWER SÃO FRANCISCO VALLEY REGION, BRAZIL." Revista Brasileira de Ciência do Solo 39, no. 4 (August 2015): 1068–78. http://dx.doi.org/10.1590/01000683rbcs20140498.
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Improper land use has lead to deterioration and depletion of natural resources, as well as a significant decline in agricultural production, due to decreased soil quality. Removal of native vegetation to make way for agricultural crops, often managed inadequately, results in soil disruption, decreased nutrient availability, and decomposition of soil organic matter, making sustainable agricultural production unviable. Thus, the aim of the present study was to evaluate the impact of growing irrigated mango (over a 20 year period) on the organic carbon (OC) stocks and on the fractions of soil organic matter (SOM) in relation to the native caatinga (xeric shrubland) vegetation in the Lower São Francisco Valley region, Brazil. The study was carried out on the Boa Esperança Farm located in Petrolina, Pernambuco, Brazil. In areas under irrigated mango and native caatinga, soil samples were collected at the 0-10 and 10-20 cm depths. After preparing the soil samples, we determined the OC stocks, carbon of humic substances (fulvic acid fractions, humic acid fractions, and humin fractions), and the light and heavy SOM fractions. Growing irrigated mango resulted in higher OC stocks; higher C stocks in the fulvic acid, humic acid, and humin fractions; and higher C stocks in the heavy and light SOM fraction in comparison to nativecaatinga, especially in the uppermost soil layer.
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Kopinke, F. D., J. P�rschmann, and M. Remmler. "Sorption Behavior of Anthropogenic Humic Matter." Naturwissenschaften 82, no. 1 (January 1, 1995): 28–30. http://dx.doi.org/10.1007/s001140050134.
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Kopinke, F. D., J. P�rschmann, and M. Remmler. "Sorption behavior of anthropogenic humic matter." Naturwissenschaften 82, no. 1 (January 1995): 28–30. http://dx.doi.org/10.1007/bf01167866.
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Lu, Yan Jun. "Characteristics of Municipal Solid Waste Composting and Determination of Composting Maturation." Advanced Materials Research 671-674 (March 2013): 2644–47. http://dx.doi.org/10.4028/www.scientific.net/amr.671-674.2644.
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The characteristics of thermophilic aerobic composting process for municipal solid waste were studied. The changes of pH and organic matter content, the infrared spectra of organic matter before and after composting, the development of humification, and the toxicity for the seed were investigated. The results indicated that: the pH quickly increased and then decreased, stabilized in the neutral range; organic matter degradation occurred mainly in the first 30 days of high temperature rapid composting stage, indicating the high temperature phase played the main role in the organic matter degradation; the increases of humus, fulvic acid, humic acid and humic acid/fulvic acid ratio also showed the conversion of organic matters to humus. Composting decreased the matters inhibiting seed germination and weakened the toxicity for the plant, and the sample reached maturity through composting.
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Murage, Evah W., and Paul Voroney. "Distribution of organic carbon in the stable soil humic fractions as affected by tillage management." Canadian Journal of Soil Science 88, no. 1 (February 1, 2008): 99–106. http://dx.doi.org/10.4141/s06-059.
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Soil humus comprises a large and stable pool of soil organic matter (SOM); hence a better understanding of the fate of C in soil humic fractions can provide valuable information for the development of alternative tillage practices that will lead to long-term soil C sequestration. We used δ13C techniques to investigate the effects of tillage on the dynamics of native (C3–C) and corn derived C (C4–C) in fulvic acid (FA), humic acid (HA) and humin fractions. Humic substances were extracted from soils cropped to corn for 11 yr and managed under either conventional (CT) or no-tillage (NT), and from a conventionally tilled soil under > 55 yr of tobacco/rye rotation. No-tillage resulted in higher proportions of C4–C in the upper 5 cm and generally lower C4–C proportions below 5 cm than CT. Up to 31, 27 and 34% of C4–C were assimilated into FA, HA and humin fractions, respectively, indicating that even the humin fraction, often described as passive, old or resistant, acted as a sink of recently added C, and that it is heterogeneous with some of its components being young. Recovery of large proportions of C3–C in the humic fractions demonstrated their importance in the long-term stabilization of SOM. Within each sampling depth, there were no unique differences in the distribution of C3–C among the three humic fractions, suggesting similar turnover of C3–C in all the fractions. Therefore, there was no unique active fraction corresponding with the concept of C pools with defined turnover characteristics used in models of SOM turnover. Key words: Soil humic fractions, corn derived C, native C, δ13C techniques, tillage practices
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Papish, Pavlo, Halyna Ivanyuk, and Ihor Papish. "Haplic chernozems humus condition of Western Bug and Styr terraced landscapes." Visnyk of the Lviv University. Series Geography, no. 50 (December 28, 2016): 296–308. http://dx.doi.org/10.30970/vgg.2016.50.8717.
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Volyn Upland Haplic Chernozems are distributed mainly on the terrace landscapes of the Western Bug and the Styr and their tributaries (Chornohuzka, Luha, Lypa). Most of these soils are old ploughlands that have experienced various types of degradation. Haplic Chernozems are low-humus soils and they have low storages of humus substance in the 20 cm arable layer and middle storages of humus in 100 cm soil thickness. There is correlation of C humic acids to C fulvic acids within 1.2–3.3 in the humus profile. Among the various fractions of humic substances the 2nd fraction associated to Calcium dominates. A content of “free” humic acids (1rst fraction) is very low and the amount of humin is low. The optical density of humic acids ( 0,001% НА Е1 cm, 465 nm ) are high and very high. The organic matter of Volyn Upland Haplic Chernozems has some regional peculiarities. First, it caused by topographical conditions of its formation and evolution in the Holocene. Chernozems of the 1st terrace of the River Western Bug are extremely deep. They have progressive-accumulative type of humus distribution in profile, humate type of humus in upper 100 cm layer, a very high degree of organic matter humification and the same content of humic fraction associated to Calcium and lowmiddle content of 3rd fraction associated to clay minerals. The molecules of humic acids in the humus horizon of Chernozems of the 1rst terrace are better structured that indicates the older age of humus in these soils. Chernozems of the 2nd terrace above the floodplain of the River Styr are middle-deep soils. They are characterised by the regressive-accumulative type of humus distribution in profile, humate-fulvate type of humus and very high degree of organic matter humification only in 25–50 cm layer. The content of fractions associated to Calcium and clay minerals is predominantly high. Key words: Haplic Chernozems, humus, humic acids, fulvic acids, optical density, humus condition.
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Schroeter, Elena R., Kevin Blackburn, Michael B. Goshe, and Mary H. Schweitzer. "Proteomic method to extract, concentrate, digest and enrich peptides from fossils with coloured (humic) substances for mass spectrometry analyses." Royal Society Open Science 6, no. 8 (August 2019): 181433. http://dx.doi.org/10.1098/rsos.181433.
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Humic substances are breakdown products of decaying organic matter that co-extract with proteins from fossils. These substances are difficult to separate from proteins in solution and interfere with analyses of fossil proteomes. We introduce a method combining multiple recent advances in extraction protocols to both concentrate proteins from fossil specimens with high humic content and remove humics, producing clean samples easily analysed by mass spectrometry (MS). This method includes: (i) a non-demineralizing extraction buffer that eliminates protein loss during the demineralization step in routine methods; (ii) filter-aided sample preparation (FASP) of peptides, which concentrates and digests extracts in one filter, allowing the separation of large humics after digestion; (iii) centrifugal stage tipping, which further clarifies and concentrates samples in a uniform process performed simultaneously on multiple samples. We apply this method to a moa fossil (approx. 800–1000 years) dark with humic content, generating colourless samples and enabling the detection of more proteins with greater sequence coverage than previous MS analyses on this same specimen. This workflow allows analyses of low-abundance proteins in fossils containing humics and thus may widen the range of extinct organisms and regions of their proteomes we can explore with MS.
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Marhaba, Taha F., and Yong Pu. "Rapid delineation of humic and non-humic organic matter fractions in water." Journal of Hazardous Materials 73, no. 3 (April 2000): 221–34. http://dx.doi.org/10.1016/s0304-3894(99)00188-0.
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Tonneijck, Femke H., Johannes van der Plicht, Boris Jansen, Jacobus M. Verstraten, and Henry Hooghiemstra. "Radiocarbon Dating of Soil Organic Matter Fractions in Andosols in Northern Ecuador." Radiocarbon 48, no. 3 (2006): 337–53. http://dx.doi.org/10.1017/s0033822200038790.
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Volcanic ash soils (Andosols) may offer great opportunities for paleoecological studies, as suggested by their characteristic accumulation of organic matter (OM). However, understanding of the chronostratigraphy of soil organic matter (SOM) is required. Therefore, radiocarbon dating of SOM is necessary, but unfortunately not straightforward. Dating of fractions of SOM obtained by alkali-acid extraction is promising, but which fraction (humic acid or humin) renders the most accurate 14C dates is still subject to debate. To determine which fraction should be used for 14C dating of Andosols and to evaluate if the chronostratigraphy of SOM is suitable for paleoecological research, we measured 14C ages of both fractions and related calibrated ages to soil depth for Andosols in northern Ecuador. We compared the time frames covered by the Andosols with those of peat sequences nearby to provide independent evidence. Humic acid (HA) was significantly older than humin, except for the mineral soil samples just beneath a forest floor (organic horizons), where the opposite was true. In peat sections, 14C ages of HA and humin were equally accurate. In the soils, calibrated ages increased significantly with increasing depth. Age inversions and homogenization were not observed at the applied sampling distances. We conclude that in Andosols lacking a thick organic horizon, dating of HA renders the most accurate results, since humin was contaminated by roots. On the other hand, in mineral soil samples just beneath a forest floor, humin ages were more accurate because HA was then contaminated by younger HA illuviated from the organic horizons. Overall, the chronostratigraphy of SOM in the studied Andosols appears to be suitable for paleoecological research.
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Huang, Shipeng, Zecheng Wang, Xiaoqi Wu, Fengrong Liao, and Jinxing Dai. "Carbon Isotopic Characteristics of Different Genetic Type Condensates in China." Energy Exploration & Exploitation 29, no. 6 (December 2011): 699–710. http://dx.doi.org/10.1260/0144-5987.29.6.699.
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Condensate pools with reservoir ages of Ordovician, Permian, Triassic, Jurassic, Cretaceous, Eogene, and Neogene were found in every giant petroliferous Basin in China. Condensates generated by sapropelic organic matters (sapropelic condensates) are of high- to over-mature stages, while the maturities of those generated by humic organic matters (humic condensates) cover a wide range, from early mature to over-mature. Carbon isotopes of 143 condensate samples were analyzed in this work, and we found that both the organic matter type and the maturity significantly influenced the isotopic composition of the condensates. The total hydrocarbon isotopic values of the humic condensates range from −29.9% to −21.7%, with an average of −26.0% (94 samples), while those sapropelic condensates are lighter generally, covering a range of −33.9% to −26.0% with an average of −29.5% (40 samples). δ13Caromatics value is strongly inheritable to the organic matter type and it combined with the δ13Csaturates value can be used to distinguish condensates of different types. δ13Caromatics value of sapropelic condensate is less than −27.5%, while the δ13Caromatics and the δ13Csaturates values of humic condensate are larger than −27.5% and −29.5%, respectively.
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Oliveira, Mara Lucia Jacinto, Ademir Sérgio Ferreira de Araujo, and Wanderley José de Melo. "CHROMIUM IN SOIL ORGANIC MATTER AND COWPEA AFTER FOUR CONSECUTIVE ANNUAL APPLICATIONS OF COMPOSTED TANNERY SLUDGE." Revista Brasileira de Ciência do Solo 39, no. 1 (February 2015): 297–302. http://dx.doi.org/10.1590/01000683rbcs20150158.
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Tannery sludge contains high concentrations of inorganic elements, such as chromium (Cr), which may lead to environmental pollution and affect human health The behavior of Cr in organic matter fractions and in the growth of cowpea (Vigna unguiculata L.) was studied in a sandy soil after four consecutive annual applications of composted tannery sludge (CTS). Over a four-year period, CTS was applied on permanent plots (2 × 5 m) and incorporated in the soil (0-20 cm) at the rates of 0, 2.5, 5.0, 10.0, and 20.0 Mg ha-1 (dry weight basis). These treatments were replicated four times in a randomized block design. In the fourth year, cowpea was planted and grown for 50 days, at which time we analyzed the Cr concentrations in the soil, in the fulvic acid, humic acid, and humin fractions, and in the leaves, pods, and grains of cowpea. Composted tannery sludge led to an increase in Cr concentration in the soil. Among the humic substances, the highest Cr concentration was found in humin. The application rates of CTS significantly increased Cr concentration in leaves and grains.
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Gerlach, M., and R. Gimbel. "Influence of Humic Substance Alteration during Soil Passage on their Treatment Behaviour." Water Science and Technology 40, no. 9 (November 1, 1999): 231–39. http://dx.doi.org/10.2166/wst.1999.0484.
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Humic substances are not major objectives of water treatment in drinking water supply. But, as they often influence the treatment efficiency or participate in treatment reactions, their behaviour in the treatment process can significantly determine the process design. A very effective pretreatment step can be achieved by soil passage (e. g. bank filtration or slow sand filtration) which is usually involved in German surface water treatment processes. In this study transport phenomena of humic matter during underground passage are investigated with special attention to the alteration of their treatment behavior. In a fundamental work the deposition of humic substances was studied in a model system. Transport phenomena could mathematically be described by a filtration theory of colloidal transport. From the results of these calculations the collision efficiencies of humic substances on clean and coated surfaces can be derived. The humic substance deposition on subsurfaces is accompanied by a classification based on molecular weight. An additional alteration of dissolved humic matter due to microbiological degradation and partial resolvation of deposited humic matter was observed by passage of river water through columns containing actual soil. The alteration of dissolved organic matter during soil passage is finally characterized by its adsorption and chlorination precursor behaviour. All results confirm that bank filtration is an effective pretreatment step particulary due to the decrease in connection with improvement in treatability of humic matter.
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Reddy, Gudigopuram B., Charles W. Raczkowski, Johnsely S. Cyrus, and Ariel Szogi. "Carbon sequestration in a surface flow constructed wetland after 12 years of swine wastewater treatment." Water Science and Technology 73, no. 10 (February 29, 2016): 2501–8. http://dx.doi.org/10.2166/wst.2016.112.
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Constructed wetlands used for the treatment of swine wastewater may potentially sequester significant amounts of carbon. In past studies, we evaluated the treatment efficiency of wastewater in a marsh–pond–marsh design wetland system. The functionality of this system was highly dependent on soil carbon content and organic matter turnover rate. To better understand system performance and carbon dynamics, we measured plant dry matter, decomposition rates and soil carbon fractions. Plant litter decomposition rate was 0.0052 g day−1 (±0.00119 g day−1) with an estimated half-life of 133 days. The detritus layer accumulated over the soil surface had much more humin than other C fractions. In marsh areas, soil C extracted with NaOH had four to six times higher amounts of humic acid, fulvic acid and humin than soil C extracted by cold and hot water, HCl/HF, and Na pyruvate. In the pond area, humic acid, fulvic acid and humin content were two to four times lower than in the marsh area. More soil C and N was found in the marsh area than in the pond area. These wetlands proved to be large sinks for stable C forms.
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Weber, Jerome B., M. Ray Tucker, and Robert A. Isaac. "Making Herbicide Rate Recommendations Based on Soil Tests." Weed Technology 1, no. 1 (January 1987): 41–45. http://dx.doi.org/10.1017/s0890037x00029092.
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Percent soil organic matter content, as determined by standard chromic acid oxidations, was highly (r = 0.89) correlated with soil humic matter content, as determined by NaOH/DTPA (diethylenetriaminepenta-acetic acid)/alcohol extraction of 201 U.S. soils. Humic matter content of the soils was equally or better correlated (r = 0.89 to 0.97) with herbicide bioactivity, as measured in field experiments, than was percent organic matter content (r = 0.87 to 0.92). Regression equations provided allow herbicide rate recommendations for 80% weed control to be calculated based on soil humic matter or soil organic matter levels.
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Leal, Otávio dos Anjos, Deborah Pinheiro Dick, José María de la Rosa, Daniela Piaz Barbosa Leal, José A. González-Pérez, Gabriel Soares Campos, and Heike Knicker. "Charcoal Fine Residues Effects on Soil Organic Matter Humic Substances, Composition, and Biodegradability." Agronomy 9, no. 7 (July 16, 2019): 384. http://dx.doi.org/10.3390/agronomy9070384.
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Biochar has been shown as a potential mean to enhance carbon sequestration in the soil. In Brazil, approximately 15% of the produced charcoal is discarded as charcoal fines, which are chemically similar to biochar. Therefore, we aimed to test charcoal fines as a strategy to increase soil carbon sequestration. Charcoal fines of hardwood Mimosa scabrella were incorporated into a Cambisol down to 10 cm (T1 = 0 and T4 = 40 Mg ha−1) in Southern Brazil. Soil samples were collected (0–30 cm) 20 months after charcoal amendment. Soil organic matter (SOM) acid extract, humic acid, fulvic acid, and humin fractions were separated. Solid-state 13C nuclear magnetic resonance (NMR) spectra from charcoal and SOM in T1 and T4 were obtained before and after 165 days of incubation under controlled conditions. Charcoal increased soil carbon as fulvic (10–20 cm) and humic acids (10–30 cm) and, especially, as humin (0–5 cm), which probably occurred due to the hydrophobic character of the charcoal. The 13C NMR spectra and mean residence times (MRT) measured from incubation essays indicated that the charred material decomposed relatively fast and MRT of T1 and T4 samples were similar. It follows that the charcoal fines underwent similar decomposition as SOM, despite the high charcoal dose applied to the soil and the high aryl C contribution (78%) to the total 13C intensity of the charcoal NMR spectra.
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Ansone-Bērtiņa, Linda, Marta Jemeļjanova, Māris Kļaviņš, Rūta Ozola-Davidāne, and Jorens Kviesis. "Clay-Humic Substance Composites for Removal of Pharmaceuticals from Water." Key Engineering Materials 850 (June 2020): 28–34. http://dx.doi.org/10.4028/www.scientific.net/kem.850.28.
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Humic substances are the main component of soil organic matter and they actively interact with substances in soils, including pollutants. Humic acid-clay mineral composite materials can be considered as prospective and low-cost sorbents for contaminant removal. The aim of this study is to develop clay mineral and humic acid composite materials and to characterise their possible applications. For this research, montmorillonite, kaolinite and bentonite were saturated with three types of humic substances: technical humic acid from lignite, humic substances extracted from raised bog peat (Latvia) and technical K humate from lignite. Obtained sorbents were characterized using FTIR. The sorption was characterised according to the chosen clay mineral and humic acid type and concentration. Comparing the influence of clay minerals and humic substances on humic matter sorption, it has been found that the sorbed amount of humic substances depend on chosen humic substances and/or clay mineral. Obtained sorbents were used for sorption of chlorpromazine. Results indicate that the most perspective sorbents for chlorpromazine removal are bentonite and bentonite modified with humic acid. However, montmorillonite-humic composites also can be used for removal of chlorpromazine from water.
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Liu, Tong Zhou, and Pin Hua Rao. "Effects of Natural Organic Matter on TCE Removal in Groundwater by Zero-Valent Iron: Batch Study." Advanced Materials Research 807-809 (September 2013): 486–89. http://dx.doi.org/10.4028/www.scientific.net/amr.807-809.486.
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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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Barisevičiūtė, Rūta, Evaldas Maceika, Žilvinas Ežerinskis, Jonas Mažeika, Laurynas Butkus, Justina Šapolaitė, Andrius Garbaras, et al. "Tracing Carbon Isotope Variations in Lake Sediments Caused by Environmental Factors During the Past Century: A Case Study of Lake Tapeliai, Lithuania." Radiocarbon 61, no. 4 (June 27, 2019): 885–903. http://dx.doi.org/10.1017/rdc.2019.63.
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ABSTRACTIn this study, we examined how land use and urbanization changes in adjacent areas affected biological productivity and carbon cycling in a lake ecosystem over 100 years and how these changes are reflected in carbon isotope variations. We performed radiocarbon (14C) activity and stable carbon isotope ratio analysis in two organic fractions: humin and humic acids of lake sediment. Additionally, we performed pigment and diatom analysis and determined the carbonate and organic matter (OM) content in sediments. Over the last century, the estimated 14C reservoir age in both sediment organic fractions varied from 1136 ± 112 yr to 5733 ± 122 yr. The increase in the reservoir age by 1175 ± 111 yr was related with higher inputs of pre-aged organic carbon and 14C depleted hard water due to the opening of the channel connecting two lakes. Nuclear weapons tests caused an increase in the reservoir age of up to 5421 ± 135 yr and 5733 ± 122 yr in humin and humic acids, respectively. 13C values in the humic acid fraction showed a tendency to decrease, depending on the content of autochthonous versus allochthonous OM in sediments, while changes in the sources of OM had a minor impact on the stable carbon isotope composition in the humin fraction.
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SAKELLARIADOU, F. "Spectroscopic studies of humic acids from subsurface sediment samples collected across the Aegean Sea." Mediterranean Marine Science 7, no. 2 (December 1, 2006): 11. http://dx.doi.org/10.12681/mms.166.
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Natural humic acids are biogenic, structurally complex and heterogeneous, refractory, acidic, yellow-to black-coloured organic polyelectrolytes of relatively high molecular weight. They occur in all soils, sediments, fresh waters, and seawaters. Humic acids represent the largest portion of nonliving soil organic matter. In the present paper, humic substances were isolated from marine subsurface sediment samples collected across the Aegean sea (in Greece) and especially from a marine area extending northwards of the Samothraki plateau towards the north-eastern part of the island of Crete. In a following step, humic preparations were studied using infrared and fluorescence spectroscopy (emission, excitation and synchronous-scan excitation spectra were obtained). The infrared spectra suggested functional chemical groups such as as OH-, C-H aliphatic, C=C, C=O/COO-, salts of carboxylic acids, and also, in some cases, silicate anions or C-O from alcohols, esters and ethers. Fluorescence emission, excitation and synchronous scan excitation provided some valuable information concerning a probable origin (marine and/or terrestrial) for the isolated humics.
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Ahmad, U. K., Z. Ujang, Z. Yusop, and T. L. Fong. "Fluorescence technique for the characterization of natural organic matter in river water." Water Science and Technology 46, no. 9 (November 1, 2002): 117–25. http://dx.doi.org/10.2166/wst.2002.0219.
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The complex nature of natural organic matter (NOM), and the impact of this matter on drinking water quality have necessitated the characterization studies of NOM. A fluorescence technique for the characterization of NOM in Malaysian river water is reported. Water samples from several river sampling sites were collected and concentrated using a low-pressure reverse osmosis (LPROM). Solid phase extraction (SPE) using C18 extraction cartridges were used to fractionate the water samples into humic and non-humic fractions. To differentiate and classify various types of humic substances, fluorescence was applied in emission, excitation and in synchronous-scan modes. A synchronous spectral profile was found to be able to differentiate humic and fulvic acids better than the emission or excitation spectra. Synchronous excitation spectra showed different spectral patterns for the water samples due to different origin. All water samples showed the presence of both fulvic and humic acids.
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Gerke, Jörg. "Humic (Organic Matter)-Al(Fe)-Phosphate Complexes." Soil Science 175, no. 9 (September 2010): 417–25. http://dx.doi.org/10.1097/ss.0b013e3181f1b4dd.
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Brinkmann, Thomas, Daniel Sartorius, and Fritz H. Frimmel. "Photobleaching of humic rich dissolved organic matter." Aquatic Sciences - Research Across Boundaries 65, no. 4 (December 1, 2003): 415–24. http://dx.doi.org/10.1007/s00027-003-0670-9.
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Deligiannakis, Yiannis, and Ioannis Konstantinou. "Natural Organic Matter/Humic Acids: Technological Applications." Journal of Environmental Chemical Engineering 3, no. 4 (December 2015): 2981. http://dx.doi.org/10.1016/j.jece.2015.05.005.
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SALES, RAFAEL PEREIRA, RODINEI FACCO PEGORARO, ARLEY FIGUEIREDO PORTUGAL, JOSÉ ALOÍSIO ALVES MOREIRA, and MARCOS KOITI KONDO. "ORGANIC MATTER FRACTIONS OF AN IRRIGATED OXISOL UNDER NO-TILL AND CONVENTIONAL TILLAGE IN THE BRAZILIAN SEMI-ARID REGION." Revista Caatinga 30, no. 2 (June 2017): 303–12. http://dx.doi.org/10.1590/1983-21252017v30n205rc.
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ABSTRACT The replacement of natural vegetation by crop systems directly impacts the soil organic matter fractions. The objective of this study was to evaluate the total organic carbon (TOC) and nitrogen (TN) contents in different fractions of the soil organic matter (SOM) of an Oxisol of the Brazilian semiarid region under different irrigated crops and different soil management systems. Seven treatments were evaluated, which consisted of two soil management systems (no-till and conventional tillage) and three crops (maize, sunflower and sorghum), using as reference the soil under a native forest (NF). The summer crops preceded common bean crops in the autumn-winter. The total organic carbon content, total nitrogen, carbon content in humic substances and their constituents (fulvic acids, humic acids and humin) and labile, non-labile and water-soluble carbon contents were evaluated two years and three months after the experiment implementation to determine the carbon lability (L) lability index (LI), partitioning index (CPI) and management index (CMI). The greatest carbon, nitrogen and organic matter contents in the soil surface layer (0.00-0.05 m) were found in crops under no-till system (NTS), especially maize. The crops under NTS presented greater carbon content in humic substances than the conventional tillage system (CTS) ones in the layer 0.05-0.10 m. The crops under NTS presented greater sustainability in the Brazilian semiarid region compared with those under CTS, as shown by their higher CMI in the soil surface layer.
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Day, GM, R. Beckett, BT Hart, and ID McKelvie. "Characterization of natural organic matter from four Victorian freshwater systems." Marine and Freshwater Research 42, no. 6 (1991): 675. http://dx.doi.org/10.1071/mf9910675.
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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.
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Palanivell, Perumal, Osumanu Haruna Ahmed, Nik Muhamad Ab Majid, Mohamadu Boyie Jalloh, and Kasim Susilawati. "Improving Lowland Rice (O. sativaL. cv. MR219) Plant Growth Variables, Nutrients Uptake, and Nutrients Recovery Using Crude Humic Substances." Scientific World Journal 2015 (2015): 1–14. http://dx.doi.org/10.1155/2015/906094.
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High cation exchange capacity and organic matter content of crude humic substances from compost could be exploited to reduce ammonia loss from urea and to as well improve rice growth and soil chemical properties for efficient nutrients utilization in lowland rice cultivation. Close-dynamic air flow system was used to determine the effects of crude humic substances on ammonia volatilization. A pot experiment was conducted to determine the effects of crude humic substances on rice plant growth, nutrients uptake, nutrients recovery, and soil chemical properties using an acid soil mixed with three rates of crude humic substances (20, 40, and 60 g pot−1). Standard procedures were used to evaluate rice plant dry matter production, nutrients uptake, nutrients recovery, and soil chemical properties. Application of crude humic substances increased ammonia volatilization. However, the lowest rate of crude humic substances (20 g pot−1) significantly improved total dry matter, nutrients uptake, nutrients recovery, and soil nutrients availability compared with crude humic substances (40 and 60 g pot−1) and the normal fertilization. Apart from improving growth of rice plants, crude humic substances can be used to ameliorate acid soils in rice cultivation. The findings of this study are being validated in our ongoing field trials.
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Catrouillet, Charlotte, Héléne Guenet, Anne-Catherine Pierson-Wickmann, Aline Dia, Martine Bouhnik LeCoz, Sarah Deville, Quentin Lenne, Yasushi Suko, and Mélanie Davranche. "Rare earth elements as tracers of active colloidal organic matter composition." Environmental Chemistry 17, no. 2 (2020): 133. http://dx.doi.org/10.1071/en19159.
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Environmental contextThe origin of organic matter at Earth’s continental surface can be either terrestrial or microbial, and its precise composition can influence its reactivity towards metals. We investigated the potential of rare earth elements to fingerprint the origin of various organic matters through their reactivity and composition. The rare earth element patterns can be useful tools to determine the reactivity and also pristine source of natural organic matter. AbstractRare earth elements (REEs) have been shown to be efficient tracers of the functional sites and/or complexes formed on humic molecules. In the present study, we test the potential of REEs to be used as tracers of the sources of humic substances (HSs). Three types of organic matter (OM) of terrestrial and microbiological origin were tested. The experiments of REEs binding to the HSs were combined with size-fractionation experiments. The REE patterns were the most fractionated in the <10kDa fraction. For Leonardite humic acid (LHA) and Aldrich humic acid (AHA), the REE patterns were consistent with the REEs binding to strong but low density sites for a low REE/C loading. By contrast, for Pony Lake fulvic acid (PLFA), the REE pattern was similar to the REE pattern developed onto a bacteria cell surface and was attributed to the REEs binding to phosphate surface sites. Fluorescence and elemental analysis of PLFA showed that the <10kDa fraction was the fraction with the stronger microbiological character, which suggested the REEs were probably bound to PLFA through REE-phosphate complexes. Such results therefore provide a new possibility for the use of REEs to assess an OM source without the need to perform numerous or complex analytical methodologies.
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Pakir, Faizal Bin, Ahmad Tarmizi Bin Abdul Karim, Felix N. L. Ling, and Khairul Anuar Kassim. "Effect of Humic Acid on Geochemistry Properties of Kaolin." Advanced Materials Research 701 (May 2013): 310–13. http://dx.doi.org/10.4028/www.scientific.net/amr.701.310.
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Organic soil is always known as problematic soil because of its engineering properties are inferior from other soft soils and/or because its behaviour may deviate from traditional rules of soil behaviour which makes it difficult to predict and design. Considerable research has been carried out over the years on organic soils, particularly peat soil which consists of various components of organic matter but the effect of particular organic matter is less reported. Hence, this study is carried out to determine the effect of humic acid (a kind of humified organic matter) on kaolin (which is widely studied). This paper addresses the influence of humic acid (30% and 50% of dry mass) on kaolins geochemistry properties namely Atterberg limits, compaction, specific gravity and Loss on Ignition (LOI). The findings of the study showed that the contents of humic acid had altered the behaviour of kaolin. The loss on ignition increased linearly with the increment of humic acid. However, the specific gravity, maximum dry density and Atterberg limits decreased with addition of humic acid. Atterberg limits decreased as the humic acid increased is believed to be due to the nature of humic acid which precipitated under acidic environment.
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Abouleish, Mohamed Y. Z., and Martha J. M. Wells. "Trihalomethane formation potential of aquatic and terrestrial fulvic and humic acids: examining correlation between specific trihalomethane formation potential and specific ultraviolet absorbance." Environmental Chemistry 9, no. 5 (2012): 450. http://dx.doi.org/10.1071/en12041.
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Environmental context When surface water is disinfected to produce potable drinking water, toxic by-products are generated by reaction with naturally occurring organic matter. The production of trihalomethane disinfection by-products was investigated for different types of well-characterised organic matter from various geographic locations. Increased understanding of the character of organic matter dissolved in water is needed for improving the ability to provide safe water and protect public health. Abstract Trihalomethanes (THMs) – a class of disinfection by-products (DBPs) including chloroform – are produced when natural water is chlorinated. Many THMs are believed to result from the reaction of chlorine with the aromatic structures in humic substances, which can be represented by ultraviolet absorbance at 254 nm (UVA). However, in the literature, plots of the specific, or carbon-normalised, UVA (SUVA) compared with the specific, or carbon-normalised, trihalomethane formation potential, THMFP (STHMFP) are poorly correlated. Therefore, well characterised samples of organic matter were obtained from the International Humic Substances Society (IHSS) to study the effect of type (fulvic acid, FA; humic acid, HA), origin (aquatic, terrestrial), geographical source (Nordic, Suwannee River, peat, soil) and pH (6, 9) on the formation of trihalomethanes. In this research, parameters expressed on a weight-average moles-of-humic substance basis were compared with those on a mass-of-carbon basis. Using factorial analysis, SUVA was statistically described by the main effect type (P = 0.0044), whereas STHMFP was statistically described by the main effects type (P = 0.0078) and origin (P = 0.0210). Separate relationships between SUVA and STHMFP normalised to moles of humic substance were defined for aquatic substances (R2 = 0.9948) and for terrestrial substances (R2 = 0.9512). The occurrence of aquatically derived fulvic-like humic acid (Suwannee River humic acid) and aquatically derived terrestrial-like humic acid (Nordic humic acid) were observed. Some aquatic substances were capable of generating levels of THMs per mole of humic substance that were greater than or equal to the most reactive terrestrial humic acid.
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Kholodov, V. A., Yu R. Farkhodov, A. Zherebker, and N. V. Yaroslavtseva. "THE ASSESSMENT OF ANALYTICAL DOUBLE-SHOT PYROLYSIS WITH GAS CHROMATOGRAPH-MASS SPECTROMETRY APPLICATION OPPORTUNITY FOR THE HUMIC MATTER INVESTIGATION IN SITU." Dokuchaev Soil Bulletin, no. 94 (September 1, 2018): 3–18. http://dx.doi.org/10.19047/0136-1694-2018-94-3-18.
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Double-shot pyrolysis with gas chromatography and mass detection (Double-shot GC MS) was conducted for a sample of typical chernozem and humic acids separated from it. The humic acids preparations were pyrolyzed at 500, 600 and 700°C. The data were compared with the lignin pyrograms witch were obtained under similar conditions. It was shown that 500°C is the optimum temperature for pyrolysis of humic acids obtained from Chernozems. Toluene in pyrolysis products may be considered as a marker of excessively high temperature occurring during the experiment. The results of a Doubleshot pyrolysis for the soil itself and the humic acids which were extracted from it were compared. Eight products of the soil pyrolysis coincided with substances determined in humic acids (with a total of 41). In the case of thermal desorption of the soil, there were only three such substances, and they also were detected during subsequent pyrolysis of the soil sample. The data obtained speak about the predominantly macromolecular composition of humic substances. The conducted works demonstrate the posibility and perspective for using the Doubleshot pyrolysis GC MS for in situ investigation of soil organic matter, humus matter in general and humic acids in particular.
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Melo, Antônia Arleudina Barros de, Gustavo Souza Valladares, Marcos Bacis Ceddia, Marcos Gervasio Pereira, and Ismail Soares. "Spatial distribution of organic carbon and humic substances in irrigated soils under different management systems in a semi-arid zone in Ceará, Brazil." Semina: Ciências Agrárias 37, no. 4 (August 30, 2016): 1845. http://dx.doi.org/10.5433/1679-0359.2016v37n4p1845.
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Spatial distribution of organic carbon and humic substances in irrigated soils under different management systems in a semi-arid zone in Ceará, Brazil Knowledge of the spatial variability in soil properties can contribute to effective use and management. This study was conducted to evaluate the spatial distribution of the levels of total organic carbon (TOC) and humic substances (humic acid (C-FAH), fulvic acid fraction (C-FAF), and humin fraction (C-HUM)) in an Ultisol under different land uses, located in the irrigated perimeter of Baixo Acaraú-CE, transition to semiarid Ceará. The distribution and spatial dependence of the humic fractions were evaluated using descriptive statistics, including semivariogram analysis and data interpolation (kriging). The TOC showed a pure nugget effect, whereas the other fractions showed moderate spatial dependence. Forested and banana cultivation areas showed similar distributions of C-FAH and C-FAF, due to the high input of organic matter (leaves and pseudostems) in the area of banana cultivation and the absence of soil disturbance in the forested area. Data interpolation (kriging) and mapping were useful tools to assess the distribution and spatial dependence of soil attributes.
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Balík, Jiří, Ondřej Sedlář, Martin Kulhánek, Jindřich Černý, Michaela Smatanová, and Pavel Suran. "Effect of organic fertilisers on glomalin content and soil organic matter quality." Plant, Soil and Environment 66, No. 11 (November 2, 2020): 590–97. http://dx.doi.org/10.17221/385/2020-pse.
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Glomalin is one of the factors with an important role at forming and stabilising soil aggregates. Long-term stationary experiments were carried out to observe the influence of various fertilisation treatments on the content of glomalin in topsoil. The content of easily extractable glomalin (EEG) and total glomalin (TG) were determined. Moreover, glomalin was also determined by using the near-infrared reflectance spectroscopy (G<sub>NIRS</sub>). Both mineral and organic fertilisation significantly increased the content of glomalin compared to the unfertilised control. However, observed differences among individual fertilisation treatments were not significant. A significant correlation was determined between the content of EEG, TG, G<sub>NIRS</sub>, and the content of humic substances as well as humic acids. Both methods used (EEG, TG) can equally reflect soil organic matter quality. A significant correlation was also recorded between the G<sub>NIRS</sub> and extraction methods (EEG, TG).
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Abakumov, E. V., O. A. Rodina, and A. K. Eskov. "Humification and Humic Acid Composition of Suspended Soil in Oligotrophous Environments in South Vietnam." Applied and Environmental Soil Science 2018 (2018): 1–8. http://dx.doi.org/10.1155/2018/1026237.
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Humification is considered to be a global process that is implemented in soils and organic sediments and also in natural water and air. The term “suspended soils” has become increasingly common in recent years. Suspended soils are defined as the part of the organic matter that has not undergone the full decomposition process and has not turned into the humus of terrestrial soils. Suspended soils were shown to contain higher total nitrogen, phosphorus, and potassium contents than the forest soil, but the moisture content in suspended soils was significantly lower. Our study of the structural composition of humic substances in suspended soils was conducted with an aim of evaluating the humification rates and structural composition of humic acids in the suspended soil in tropical forests of South Vietnam. Soil samples from three selected areas were investigated: the soil under phorophytes (mineral soil presented by samples of topsoil of the typical dry savanna landscape) and two soils from epiphytous formations. Samples were collected from savanna-type sparse communities, located on oligotrophous plains in Phú Quốc Island (South Vietnam) in 2015. General properties of the soil and the elemental composition of suspended soils were determined, and the humic substance chemical composition was evaluated using solid state 13C-NMR. Data obtained showed that the pH of the soils under phorophytes was higher than in the suspended soils; basal respiration did not tend to change indices between soils under phorophytes and suspended soils, but the suspended soil was less enriched by nitrogen than the soil under phorophytes. This can be related to the total amount of organic matter exposed to humification in various soils and to the presence of an essential portion of mineral particles in the soil under phorophytes. Data on elemental composition of the humic acids (HAs) indicated that one method of humification is implemented in all three soils that were investigated. The humic acids of the phorophyte soil showed the same content of aromatic fraction as the suspended soil. The most comparable soil type in terms of humic substance composition is Cambisols from humid forests of subboreal and subtropical zones. The humification process implemented in suspended soils showed the absence of mineral compounds or mineral fine earth, which indicated that humification in conditions of pure organic substrates can result in formation of deep humified organic matter, as shown by humic acids with an essential aromatic fraction content.
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Kaushal, Nikita, Liudongqing Yang, Jani T. I. Tanzil, Jen Nie Lee, Nathalie F. Goodkin, and Patrick Martin. "Sub-annual fluorescence measurements of coral skeleton: relationship between skeletal luminescence and terrestrial humic-like substances." Coral Reefs 39, no. 5 (May 28, 2020): 1257–72. http://dx.doi.org/10.1007/s00338-020-01959-x.
Full textAbstract:
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.
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Trickovic, Jelena, Ivana Ivancev-Tumbas, Marijana Kragulj, Miljana Prica, Dejan Krcmar, Aleksandar Nikolic, and Bozo Dalmacija. "Lindane sorption and desorption behaviour on sediment organic matter." Journal of the Serbian Chemical Society 78, no. 6 (2013): 883–95. http://dx.doi.org/10.2298/jsc120706104t.
Full textAbstract:
The work is concerned with the sorption and desorption behaviour of lindane on four humic acid fractions (HAs) and two humin fractions, sequentially extracted from Ludas lake sediment. All sorption isotherms, fitted to a Freundlich model, were nonlinear. The isotherm linearity increased from 0.757 for the first extracted HA to 0.944 for the ninth HA showing a positive correlation with atomic H/C ratio, while a negative correlation between sorption coefficient and aliphaticity of the isolated HAs was observed. It has been shown that the sorption processes may be strongly influenced by the physical conformation of and accessibility to sediment organic matter (SOM), as demonstrated by high Koc and low n values of humin samples. Despite exhibiting the most nonlinear sorption isotherms, humin samples did not show a pronounced sorption-desorption hysteresis, while the most significant hysteresis was observed for three HA samples. These results support the hypothesis that the aromatic domains in SOM influence strongly the sorption and desorption behaviour of lindane. Our findings may be helpful in understanding the distribution, transport and fate of lindane in soils and sediments.
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BARRIUSO, E., J. M. PORTAL, and F. ANDREUX. "CINÉTIQUE ET MÉCANISME DE L'HYDROLYSE ACIDE DE LA MATIÈRE ORGANIQUE D'UN SOL HUMIFÈRE DE MONTAGNE." Canadian Journal of Soil Science 67, no. 3 (August 1, 1987): 647–58. http://dx.doi.org/10.4141/cjss87-061.
Full textAbstract:
From the surface horizon of an organic-rich mountain soil, humic and fulvic acids, and organo-mineral compounds including clay and hydroxy-metal colloids, were separated and purified. Each of these fractions was hydrolyzed in 3.0 M HCl under reflux, then the reaction parameters related to the solubilization of carbon and nitrogen and to the kinetics of hydrolysis were calculated. Acid hydrolysis was interpreted as the result of two successive steps: first a rapid electrophilic attack of heteroatomic C-O and C-N bonds by protons, then a slow nucleophilic hydration of the protonated bonds. Electron delocalization in these bonds, which increased with the polycondensation degree of organic compounds, and with their adsoprtion on mineral surfaces, resulted in an increase in their stability to hydrolysis. Fulvic acids were found to be the less stable material, and lead to predominantly anionic hydrolysis products. Clay-sized humin was the most stable material and yielded mainly cationic hydrolysates. The stability to hydrolysis and the humification degree of organic matter in the fractions generally coincided, and decreased in the following order: fine clay-sized humin > alkali dispersible organo-mineral colloids > > humic acids > hydroxy-ferric organic colloids > hydroxy-aluminium organic colloids = fulvic acids. Key words: Organo-mineral complex, humic substances, acid hydrolysis, carbon, nitrogen
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N'dayegamiye, A., and D. A. Angers. "Organic matter characteristics and water-stable aggregation of a sandy loam soil after 9 years of wood-residue applications." Canadian Journal of Soil Science 73, no. 1 (February 1, 1993): 115–22. http://dx.doi.org/10.4141/cjss93-011.
Full textAbstract:
The long-term effects of wood-residue applications on soil properties are not well documented. This study was undertaken to characterize the organic matter and aggregation of a sandy loam after 9 yr of biennial application of wood residues (tree clippings) at rates of 25, 50 and 100 Mg ha−1 with and without nitrogen fertilization. Carbon (C) and nitrogen (N) contents of the whole soil were determined as well as the C content of the density fractions and of the fractions soluble and insoluble to Na4P2O7. In comparison with the control, the whole-soil C content was 16–24% higher following application of wood residues alone and 16–37% higher for application of wood residues supplemented with nitrogen. The treatments had no effect on soil water-stable macroaggregation (> 250 μm). Wood-residue applications had no effect on the humic material (soluble in Na4P2O7) but favored the humin-C content (the fractions insoluble in Na4P2O7) by 25–60% relative to the control. The light-fraction organic matter was on average 68% larger, and the heavy fraction 17% larger, in the treated soils than in the control. On average, 80% of the differences in total organic C induced by residue application could be attributed to differences in the humin and heavy fractions. The long-term effect of wood-residue applications to the soil was, therefore, reflected in an accumulation of the more stable organic matter present as heavy and humin fractions. In addition, the differences in the light fractions suggested a short-term effect of wood-residue applications.Key words: Light and heavy fractions, wood residues, organic C, water-stable aggregates, humic acids, humins
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Kaštelan-Macan, M., and M. Petrovic. "Competitive sorption of phosphate and marine humic substances on suspended particulate matter." Water Science and Technology 32, no. 9-10 (November 1, 1995): 349–55. http://dx.doi.org/10.2166/wst.1995.0702.
Full textAbstract:
The sorption behavior of dissolved orthophosphate in the presence of background organics has been evaluated by studying the sorption on suspended particles (sand, calcite, bentonite and iron oxide). Humic and fulvic acids, that are the most significant component of organic substances in aquatic systems, were used as competitive solutes. Marine humic substances were isolated from the surface part of the sediment collected in Raska bay, Adriatic sea. Since the phenomena of phosphate fixation are especially important in estuarine waters, when fresh and saline waters undergo mixing in the coastal zone, the influence of salinity was studied. It was found that the following effects could be considered: - reduced phosphate fixation due to favorable sorption of humic substances onto suspended particles, - enhanced sorption induced by increased salinity and concentration of Ca2+-ions which enabled the bridging between sorbed humic acids and phosphate.