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Sample records for humic substances seminar

  1. Isolation of haloorganic groundwater humic substances

    DEFF Research Database (Denmark)

    Krog, M.; Grøn, C.

    1995-01-01

    Humic substances were isolated from groundwater according to a revised method designed to avoid organohalogen artefacts. The prepared humic substances exhibited lower halogen contents than humic substances isolated according to the conventionally used method. Excessive oxidation or hydrolysis...

  2. Unique properties of humic substances from sapropel

    Science.gov (United States)

    Rumyantsev, V. A.; Mityukov, A. S.; Kryukov, L. N.; Yaroshevich, G. S.

    2017-04-01

    Sapropel from inland Russian water reservoirs is becoming a popular raw material for medicinal purposes, production of sorbents, organomineral fertilizers, and food supplements. A comparative study of the granulometric and biological properties of humic substances obtained from sapropel in a typical way and using ultrasonic treatment of the relevant reaction masses was performed at the Institute of Limnology of the Russian Academy of Sciences. It is shown that the humic substances of sapropel with an increased content of nanoparticles used as veterinary preparations lead to a significant economic effect without using imported preparations.

  3. On the nature of humic substances

    Science.gov (United States)

    Fedotov, G. N.; Shoba, S. A.

    2015-12-01

    It is argued that the isolation of low-molecular-weight compounds from humic substances does not prove their supramolecular nature, because small molecules can be sorbed on macromolecules by interacting with them due to noncovalent bonds. The relative mobility of molecular segments in humic substances has been proposed to be used as a criterion for the discrimination between the humic substances of supraand macromolecular nature. The macromolecules are characterized by mobility of their segments, whereas supramolecular systems have stiff structure. This difference between macroand supramolecules results in different behaviors of the matrices (gels) formed from them in the processes of segregation. In the macromolecules, the formations of a new phase appearing at the segregation (microphase separation) are of nano size, at least in one dimension. They are incapable of moving within the matrix and form a well-known, limited set of systems. In the supramolecular matrices, the new-phase formations should have higher mobility and ability to move within the matrix with the formation of particles and zones of not only nano, but also micro sizes, as well as a significantly larger set of systems, including fractal configurations. The experimental electron microscopic study of the humic matrices of soil gels shows that the new-phase formations in the matrix of humic substances have not only nano, but also micro sizes and are capable of moving within the matrix, which confirms the supramolecular nature of humic substances. The proposed method has allowed generalizing the supraand macromolecular approaches, because macromolecules can enter into the composition of supramolecular systems. It is no less important that the behavior of HSs can be perceived as the behavior of stiff impenetrable particles that may compose the structures of different types and sizes.

  4. Humic substances in a soil treated with household compost under ...

    African Journals Online (AJOL)

    Tillage (hoeing) significantly enhanced the formation of humic substances (HS) in the soil. Formation of humic substance (HS) was not favoured by fertilizer application which gave lower % HS than the control. Fulvic acid fraction was higher in compost amended soil. Nigerian Journal of Soil Science Vol. 15 2005: 86-89 ...

  5. Humic Substances: Possibility of New Therapeutic Application

    Directory of Open Access Journals (Sweden)

    Natália Noronha Ferreira

    2015-12-01

    Full Text Available Humic substances (HS are heterogeneous molecular aggregates, which have no defined structure and constitute the principal fraction of natural organic matter. They can act as complexation agents, due to their high density of functional groups, and therefore directly influence the transport, accumulation, bioavailability and toxicity of different substances. Metals are important environmental pollutants, since they are widely used during human activities, and following release are not either chemically or biologically degraded. Treatment of acute poisoning in humans caused by potentially toxic metals has employed complexation agents such as ethylenediaminetetraacetic acid (EDTA or -aminoacids. However, some limitations of these materials such as the lack of selectivity of EDTA and the high cost of -aminoacids have provided the incentive for a search for alternatives. Previous studies of the properties of HS indicate their possible use as an alternative to these chelanting agents.

  6. IMMOBILISATION OF HUMIC SUBSTANCES USING PLASMA MODIFICATION

    Directory of Open Access Journals (Sweden)

    Pavlína Hájková

    2015-04-01

    Full Text Available This paper presents a study of the immobilization of humic substances (HSs on a polypropylene (PP nonwoven fabric. In order to attach the HSs, the PP nonwoven fabric was modified in a volume of nonthermal atmospheric pressure dielectric barrier discharge (DBD under defined conditions. An unmodified PP nonwoven fabric was used as a reference sample. The modified and unmodified samples were both dipped in an aqueous solution of potassium humate, and then the samples were washed in water and the amount of HSs attached to the PP fabric was monitored. An aqueous solution of cadmium salts was filtered through the treated fabric, the content of Cd2+ in the solution was monitored using ICP-OES analysis, and the Cd2+ sorbed on the fabric was proved by SEM/EDS analysis. The efficiency of the PP plasma modification was proved by XPS analysis, and the presence and the distribution of the HSs along the fibers was proved by SEM analysis.

  7. Humic substances interfere with detection of pathogenic prion protein

    Science.gov (United States)

    Smith, Christen B.; Booth, Clarissa J.; Wadzinski, Tyler J.; Legname, Giuseppe; Chappell, Rick; Johnson, Christopher J.; Pedersen, Joel A.

    2014-01-01

    Studies examining the persistence of prions (the etiological agent of transmissible spongiform encephalopathies) in soil require accurate quantification of pathogenic prion protein (PrPTSE) extracted from or in the presence of soil particles. Here, we demonstrate that natural organic matter (NOM) in soil impacts PrPTSE detection by immunoblotting. Methods commonly used to extract PrPTSE from soils release substantial amounts of NOM, and NOM inhibited PrPTSE immunoblot signal. The degree of immunoblot interference increased with increasing NOM concentration and decreasing NOM polarity. Humic substances affected immunoblot detection of prion protein from both deer and hamsters. We also establish that after interaction with humic acid, PrPTSE remains infectious to hamsters inoculated intracerebrally, and humic acid appeared to slow disease progression. These results provide evidence for interactions between PrPTSE and humic substances that influence both accurate measurement of PrPTSE in soil and disease transmission.

  8. Mechanisms of humic substances degradation by fungi

    Science.gov (United States)

    Chen, Y.; Hadar, Y.; Grinhut, T.

    2012-04-01

    Humic substances (HS) are formed by secondary synthesis reactions (humification) during the decay process and transformation of biomolecules originating from plants and other dead organisms. In nature, HS are extremely resistant to biological degradation. Thus, these substances are major components in the C cycle and in the biosphere and therefore, the understanding of the process leading to their formation and transformation and degradation is vital. Fungi active in the decomposition process of HS include mainly ascomycetes and basidiomycetes that are common in the upper layer of forest and grassland soils. Many basidiomycetes belong to the white-rot fungi (WRF) and litter-decomposing fungi (LDF). These fungi are considered to be the most efficient lignin degraders due to their nonspecific oxidizing enzymes: manganese peroxidase (MnP), lignin peroxidase (LiP) and laccase. Although bacteria dominate compost and participate in the turnover of HS, their ability to degrade stable macromolecules such as lignin and HS is limited. The overall objectives of this research were to corroborate biodegradation processes of HS by WRF. The specific objectives were: (i) To isolate, identify and characterize HS degrading WRF from biosolids (BS) compost; (ii) To study the biodegradation process of three types of HS, which differ in their structure, by WRF isolated from BS compost; and (iii) To investigate the mechanisms of HA degradation by WRF using two main approaches: (a) Study the physical and chemical analyses of the organic compounds obtained from direct fungal degradation of HA as well as elucidation of the relevant enzymatic reactions; and (b) Study the enzymatic and biochemical mechanisms involved during HA degradation. In order to study the capability of fungi to degrade HS, seventy fungal strains were isolated from biosolids (BS) compost. Two of the most active fungal species were identified based on rDNA sequences and designated Trametes sp. M23 and Phanerochaetesp., Y6

  9. Humic Substances and Mineral Elements Contents of White Grubs ...

    African Journals Online (AJOL)

    ABSTRACT: The humic substances and mineral elements content of white grubs (WG) and waste deposit (WD) were analyzed. WG was found to contain higher amount of fulvic acid (16.05 ± 4.28%) and humic acid (9.50 ± 2.06 %) compared to the respective value of 2.75 ± 0.38% and 4.25 ± 1.05 %. It could be inferred that ...

  10. Imidacloprid adsorption by soils treated with humic substances ...

    African Journals Online (AJOL)

    Imidacloprid adsorption by soils treated with humic substances under different pH and temperature conditions. ... and temperature. Thus, exogenous HA can be used to control the mobility of soil pesticide under appropriate conditions to decrease pesticide pollution diffusion and probably increase effectiveness of pesticides.

  11. Destruction of humic substances by pulsed electrical discharge

    OpenAIRE

    Lobanova, Galina Leonidovna; Yurmazova, Tatyana Aleksandrovna; Shiyan, Lyudmila Nikolaevna; Machekhina, Ksenia Igorevna; Davidenko, M. A.

    2017-01-01

    Currently, the water recourses in the territory of Tomsk region are groundwater which is limited to the high concentration of iron and manganese ions and organic substances. These impurities present in water in different forms such as soluble salts ant the colloid forms. Therefore, the present work is a part of a continuations researcher of the processes in natural waters containing humic substances at the influence of pulsed electrical discharges in a layer of iron pellets. It is shown that ...

  12. Hydrophilic interaction liquid chromatography method for measuring the composition of aquatic humic substances

    KAUST Repository

    Wang, Renqi

    2015-01-01

    A hydrophilic interaction liquid chromatography (HILIC) method was developed to measure the composition of humic substances from river, reservoir, and treated wastewater based on their physicochemical properties. The current method fractionates the humic substances into four well-defined groups based on parallel analyses with a neutral and a cationic HILIC column, using mobile phases of varied compositions and pH. The results indicate that: (i) the proportion of carboxylic acids in the humic substances from terrestrial origins is less than half of that from treated wastewater (Jeddah, KSA), (ii) a higher content of basic compounds was observed in the humic substances from treated wastewater and Ribou Reservoir (Cholet, France) than in the sample from Loire River (France), (iii) a higher percentage of hydrophobic macromolecules were found in the humic substances from Loire River than in the other samples, and (iv) humic substances of treated wastewater contained less ionic neutral compounds (i.e., pKa 5-9) than the waters from terrestrial origins. The physicochemical property disparity amongst the compounds in each humic substances sample was also evaluated. The humic substances from the lightly humic Loire river displayed the highest disparity, whereas the highly humic Suwannee river (Georgia, USA) showed the most homogeneous humic substances.

  13. Humic substances. Part 1: Dissolved humic substances (HS) in aquaculture and ornamental fish breeding.

    Science.gov (United States)

    Meinelt, Thomas; Schreckenbach, Kurt; Pietrock, Michael; Heidrich, Stefan; Steinberg, Christian E W

    2008-01-01

    Changing environmental conditions and handling stress are well known to cause chronic or acute stress situations in fish with subsequent infections. These requires a therapy by means of antibiotics and chemicals. In contrast to the huge number of pathogens, only a few substances are permitted for application as therapeutics in German aquaculture. Hence, there emerges an urgent need for highly effective and residueless alternatives. The prophylactic stimulation and training of the defense system of fish by alternative approaches becomes increasingly necessary. One approach is the application of dissolved humic substances (HS) of natural or artificial origin. For example, there exist several reports on the positive effect of HS to fishes. These effects shall be considered in detail. Furthermore, the impact of HS on the constitution of parasites and pathogens will be displayed. The reports on this issue are diverse, if not inconsistent. We try to shed some light on these discrepancies. The last aspect covered by this review is the outdated paradigm that calcium ions act as antidotes. In the presence of HS, even the opposite effect may occur. To overcome old paradigms on HS and their potential interactions with fish and fish parasites, we reviewed recent international literature, as well as 'grey' literature. We also include results from own former and ongoing studies. HS are able to increase the physiological condition of the individuals and to reduce adverse physiological and histological consequences caused by stress; the mechanism behind remains obscure. HS detoxify heavy metals and organic pollutants. Damages caused by several fish pathogens, such as bacteria and parasites, can be repaired more quickly in the presence of HS. Some parasites--mainly fungi--appear to be directly affected by HS. Comparing the fungicidal effects of HS from various sources, evidence is increasing that the aliphatic moiety may be the effective structures. However, further research is

  14. Characterization of humic substances: implications for trihalomethane formation.

    Science.gov (United States)

    Uyguner, Ceyda Senem; Hellriegel, Christine; Otto, William; Larive, Cynthia K

    2004-03-01

    Humic substances are precursors of carcinogenic trihalomethanes (THMs) formed during disinfection by chlorination in water treatment processes. In an effort to understand the relationship between trihalomethane formation potential (THMFP) and physicochemical properties of humic substances, UV-visible absorbance, fluorescence in emission and synchronous scan modes, and NMR spectra were measured for several aquatic fulvic and humic acids. For comparison, a soil fulvic acid was also examined using these methods. The feasibility of the gradient modified spin-echo (GOSE) NMR experiment to selectively measure singlet resonances arising from isolated protons was examined. In addition, diffusion coefficients were measured for DMSO solutions of the fulvic acids using BPPLED and GOSE-edited pulse sequences. Although none of the methods tested produced results that correlated with THMFP, the GOSE intensities determined for different regions of the NMR spectra did reflect the relative abundance of different types of functional groups produced by lignin oxidation. In addition, the GOSE-edited diffusion results suggest that the isolated protons, those most reactive to chlorination, are more likely contained in the larger molecular weight fractions of fulvic acids.

  15. Effects of humic substances on fluorometric DNA quantification and DNA hybridization

    NARCIS (Netherlands)

    Bachoon, DS; Otero, E; Hodson, RE

    2001-01-01

    DNA extracts from sediment and water samples are often contaminated with coextracted humic-like impurities, Estuarine humic substances and vascular plant extract were used to evaluate the effect of the presence of such impurities on DNA hybridization and quantification. The presence of humic

  16. Short communication: Biochemically active humic substances in contrasting agricultural managements

    Energy Technology Data Exchange (ETDEWEB)

    Benitez, E.; Nogales, R.; Doni, S.; Masciandaro, G.; Moreno, B.

    2016-11-01

    Because their crucial role in several soil biochemical cycles and their fast response to changes in soil management, extracellular enzymes activities are widely used as sensitive indicators of ecological change and soil quality. The aim of this work was to determine the effects of soil management on the stable pool of soil carbon cycling enzymes as indicators of essential functions. For this, extracellular β-glucosidase enzymes bounded by humic acids (C higher than 104 Da) were used to compare four long-term contrasting agricultural managements in a rainfed olive orchard representative of semi-arid Mediterranean habitats. The study was conducted for 30 years by designing a random-block of four treatments (nude vs. covered soils) and four replicates. Maintaining cover crops through fall, winter and early spring provoked a more stable and active pool of extracellular β-glucosidase in soils only if spontaneous vegetation was managed with mechanical methods. When herbicides were used during 30 years, the pattern of the molecular composition and activity of humus β-glucosidase complexes were similar in covered and nude soils, although higher activity was retrieved in the former. Tillage management increased carbon mineralization and the level of humic substances and the activity of β-glucosidase humic-bound were quite lower than in the rest of treatments. Given the ecological role of extracellular soil carbon cycling enzymes, the characterization of humus β-glucosidase complexes could be an adequate indicator of sustainability of agricultural management systems. (Author)

  17. Pyrolysis-GC-FTIR for structural elucidation of aquatic humic substances

    Energy Technology Data Exchange (ETDEWEB)

    Kuckuk, R. (Inst. fuer Spektrochemie und Angewandte Spektroskopie (ISAS), Dortmund (Germany)); Hill, W. (Inst. fuer Spektrochemie und Angewandte Spektroskopie (ISAS), Dortmund (Germany)); Burba, P. (Inst. fuer Spektrochemie und Angewandte Spektroskopie (ISAS), Dortmund (Germany)); Davies, A.N. (Inst. fuer Spektrochemie und Angewandte Spektroskopie (ISAS), Dortmund (Germany))

    1994-11-01

    Substructure components of various aquatic humic substances were investigated by a coupled pyrolysis - gas chromatography - Fourier-transform infrared spectroscopy (Py-GC-FTIR) procedure. The humic substances studied gave similar pyrolysis products, but in varying proportions. Many of the pyrolysis products (e.g. methanol, acetone, alkylbenzenes, cyclopentane, aliphatic and aromatic organic acids, acetamide, pyrrole and phenols) could be identified by their FTIR spectra using a digital library for automatic comparison. Some of the compounds are related to lignin fragments which form a large part of the humic substances investigated. Other products give hints to the involvement of tetrapyrroles, fatty acids, furanoses and amino compounds in the structure of humic macromolecules. (orig.)

  18. Response of humic-reducing microorganisms to the redox properties of humic substance during composting.

    Science.gov (United States)

    Zhao, Xinyu; He, Xiaosong; Xi, Beidou; Gao, Rutai; Tan, Wenbing; Zhang, Hui; Huang, Caihong; Li, Dan; Li, Meng

    2017-12-01

    Humic substance (HS) could be utilized by humus-reducing microorganisms (HRMs) as the terminal acceptors. Meanwhile, the reduction of HS can support the microbial growth. This process would greatly affect the redox conversion of inorganic and organic pollutants. However, whether the redox properties of HS lined with HRMs community during composting still remain unclear. This study aimed to assess the relationships between the redox capability of HS [i.e. humic acids (HA) and fulvic acids (FA)] and HRMs during composting. The results showed that the changing patterns of electron accepting capacity and electron donating capacity of HS were diverse during seven composting. Electron transfer capacities (ETC) of HA was significantly correlated with the functional groups (i.e. alkyl C, O-alkyl C, aryl C, carboxylic C, aromatic C), aromaticity and molecular weight of HA. Aromatic C, phenols, aryl C, carboxylic C, aromaticity and molecular weight of HS were the main structuralfeatures associated with the ETC of FA. Ten key genera of HRMs were found significantly determine these redox-active functional groups of HS during composting, thus influencing the ETC of HS in composts. In addition, a regulating method was suggested to enhance the ETC of HS during composting based on the relationships between the key HRMs and redox-active functional groups as well as environmental variables. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Production of humic substances through coal-solubilizing bacteria

    Directory of Open Access Journals (Sweden)

    Nelson Valero

    2014-09-01

    Full Text Available In this paper, the production of humic substances (HS through the bacterial solubilization of low rank coal (LRC was evaluated. The evaluation was carried out by 19 bacterial strains isolated in microenvironments with high contents of coal wastes. The biotransformed LRC and the HS produced were quantified in vitro in a liquid growth medium. The humic acids (HA obtained from the most active bacterial strain were characterized via elemental composition (C, H, N, O, IR analyses, and the E4/E6 ratio; they were then compared with the HA extracted chemically using NaOH. There was LRC biotransformation ranged from 25 to 37%, and HS production ranged from 127 to 3100 mg.L-1. More activity was detected in the isolated strains of Bacillus mycoides, Microbacterium sp, Acinetobacter sp, and Enterobacter aerogenes. The HA produced by B. mycoides had an IR spectrum and an E4/E6 ratio similar to those of the HA extracted with NAOH, but their elemental composition and their degree of aromatic condensation was different. Results suggest that these bacteria can be used to exploit the LRC resulting from coal mining activities and thus produce HS in order to improve the content of humified organic matter in soils.

  20. Soil humic substances hinder the propagation of prions

    Science.gov (United States)

    Leita, Liviana; Giachin, Gabriele; Margon, Alja; Narkiewicz, Joanna; Legname, Giuseppe

    2013-04-01

    capacity of clay minerals; however the contribution of soil organic components in adsorption has so far been neglected, as they represent a minor soil fraction on a weight basis. Among organic molecules, humic substances (HSs) are natural polyanions that result among the most reactive compounds in the soil and possess the largest specific surface area. Humic substances make up a large portion of the dark matter in humus and consist of heterogeneous mixtures of transformed biomolecules exhibiting a supramolecular structure. HSs are classified as humic acids (HAs), which are soluble only in alkaline solutions, and fulvic acids (FAs), which are soluble in both alkaline and acid solutions. The amphiphilic characteristics confer to HAs and FAs great versatility to interact with xenobiotics and reasonably also with prion proteins and/or prions too, leading to the formation of adducts with peculiar chemical and biophysical characteristics, thus affecting the transport, fixation and toxicity of prion. Results from our chemical, biophysical and biochemical investigation will be presented and results on anti-prion activity exerted by HAs and FAs will be provided, thus suggesting that amendment of contaminated soil with humic substances could be a strategy to contrast prion diffusion.

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

    Directory of Open Access Journals (Sweden)

    Diego Magalhães de Melo*

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

  2. CAPILLARY ELECTROPHORESIS IN THE ANALYSIS OF HUMIC SUBSTANCES FACTS AND ARTIFACTS

    Science.gov (United States)

    Humic substances, extracted as mixtures from soil and surface waters according to their solubility in acids and bases, are relatively high-molecular-mass polyelectrolytes containing aromatic, aliphatic and heterocyclic subunits. The degree of ionization of their phenolic and carb...

  3. Synthetic humic substances and their use for remediation of contaminated environments

    Science.gov (United States)

    Dudare, Diana; Klavins, Maris

    2014-05-01

    Soils are increasingly subjected to different chemical stresses, because of increasing industrialization process and other factors. Different anthropogenic compounds (organic or inorganic in nature) upon entering the soil, may not only influence its productivity potential, but may also affect the quality of groundwater and food chain. Consequently, soils of different environments contain a complex mixture of contaminants, such as oil products, metals, organic solvents, acids, bases and radionuclides. Thereby greater focus should be paid to risk assessment and evaluation of remedial techniques in order to restore the quality of the soil and groundwater. The treatment technologies presently used to remove contaminants are physical, chemical and biological technologies. Many functional groups in the structure of humic substances determine their ability to interact with metal ions forming stable complexes and influencing speciation of metal ions in the environment, as well mobility, behaviour and speciation forms in the environment. Humic substances are suggested for use in the remediation of environments contaminated with metals, owing to complex forming properties. Several efforts have been undertaken with respect to synthesize humic substances for their structural studies. At the same time the real number of methods suggested for synthesis of humic substances is highly limited and their synthesis in general has been used mostly for their structural analysis. The present study deals with development of approaches for synthesis of humic substances with increased complex forming ability in respect to metal ions. Industrially produced humic substances (TEHUM) were used for comparison and after their modification their properties were analyzed for their elemental composition; functional group content changes in spectral characteristics. Synthetic humic substances showed significant differences in the number of functional groups and in ability to interact with the metal

  4. Characterization of humic-like substances in Arctic aerosols

    Science.gov (United States)

    Nguyen, Quynh T.; Kristensen, Thomas B.; Hansen, Anne Maria K.; Skov, Henrik; Bossi, Rossana; Massling, Andreas; Sørensen, Lise L.; Bilde, Merete; Glasius, Marianne; Nøjgaard, Jacob K.

    2014-04-01

    Humic-like substances (HULIS) are a complex group of relatively high molecular weight organic compounds which contribute considerably to the mass of organic carbon (OC) and influence the light-absorbing properties of aerosols. In this work, HULIS were investigated for the first time in the high-Arctic atmosphere, focusing on the chemical characterization and mass contribution of HULIS to the total suspended particle (TSP) mass using weekly aerosol samples collected at Station Nord, northeast Greenland every fourth week during 2010. Average HULIS-C concentration was 11 ng C m-3 during the darker months (November-April) and 4 ng C m-3 during the other months (May-October) with an annual mass concentration of 0.02 ± 0.01 µg m-3. HULIS-C contributed to 3-16% of water-soluble organic carbon (WSOC), whereas HULIS accounted for 0.7-4.1% of TSP mass, with TSP typically below 1.0 µg m-3. Concentrations of OC, WSOC, HULIS, selected HULIS functional groups (carboxylic acids, aromatic carboxylic acids, and organosulfates) and levoglucosan overlapped with the typical Arctic haze pattern with elevated concentrations during winter to early spring. The aromatic carboxylic acid portion accounted for a larger share of total carboxylic acid of HULIS during the darker months (7%) compared to the brighter months (3%). The more abundant aromatic carboxylic acid functional groups and the moderate correlation between HULIS and levoglucosan concentrations during the darker months both indicate that biomass burning aerosols and thereby emissions of aromatic compounds could contribute to HULIS in the Arctic, especially during late winter. During the brighter months, relatively higher average molecular weight of HULIS was observed.

  5. Effect of phosphate on removal of humic substances by aluminum sulfate coagulant.

    Science.gov (United States)

    Cheng, Wen Po; Chi, Fung Hwa; Yu, Ruey Fang

    2004-04-01

    The presence of humic acid may change the way phosphate is absorbed or stabilized by soil and how it influences the growth of plants. The binding of phosphate with the humic substance requires bridging between phosphate ions and humic acid by metal ions, such as aluminum or iron ions. The bridging reaction can take place in peat and allophane soil under acidic conditions, altering the effectiveness of the phosphate in soil. Whether ternary phosphate-metal-HA complexes are actually formed has not yet been verified. This study considers variation in fluorescence intensity (FI) under various coagulation conditions to assess the mechanism by which humic acids and phosphate react with aluminum ions. A bond between the functional group of the humic acid and the electron-releasing group of the phosphate will enhance the florescent intensity of humic acids. Consequently the removal efficiency of humic acid, measured by florescence, declines as the phosphate concentration increases at low pH. This observation suggests that at low coagulation pH, the positively charged aluminum species can be used to bridge between the phosphate ion and the humic acid molecules.

  6. Origin and structures of groundwater humic substances from three Danish aquifers

    DEFF Research Database (Denmark)

    Grøn, C.; Wassenaar, L.; Krog, M.

    1996-01-01

    and halogens, hydrolyzable amino acids and carbohydrates, carbon isotopes) applied to aquatic humic and fulvic acids led to consistent structural interpretations for each of the three aquifers studied. For humic substances in two-aquifers, the analyses suggested source rocks in agreement with geological...... and hydrogeochemical information. In a third aquifer, source rock identification was inconclusive, and multiple fossil and recent organic carbon sources are suggested....

  7. Utilizing Coal Ash and Humic Substances as Soil Ameliorant on Reclaimed Post-Mining Land

    Directory of Open Access Journals (Sweden)

    Ade Mariyam Oklima

    2014-09-01

    Full Text Available Coal ash and humic substances can be used as soil ameliorant in the reclamation of formerly mined land. Due to its high pH and nutrients content, coal ash can be used to improve the chemical properties of the soil, such as increasing of pH, and increasing the levels of nutrients availability in the soil. Humic substances may also be used to complement, as they can increase the release of nutrients from the coal ash. Thus, the objective of this study was to assess the influence of coal ash and humic substances on soil chemical characteristics, nutrient absorption, and plant growth. This study was conducted in two locations - in a nursery area, involving two treatment factors: coal ash at different dosages (0, 200, and 400 g polybag-1, and humic material also at varying dosages (0, 0.04, and 0.08 g C polybag-1; and in a post-mining field using similar treatments: coal ash dosage (0, 2.5, and 5.0 kg planting-1 hole and humic material dosage (0, 0.56, and 1.12 g C planting hole-1. The results showed that coal ash and humic materials significantly increased the soil pH, available P, and exchangeable K, Ca and Mg. Coal ash also contained a number of heavy metals but in quantities that are far below the limits set by both Indonesian Government Regulation and the US Environmental Protection Agency (USEPA. The above soil amelioration effects mean that. applicaton of coal ash and humic substances can significantly increase the growth of Jabon trees in the reclaimed post-mining land.

  8. The density of humic acids and humic like substances (HULIS from fresh and aged wood burning and pollution aerosol particles

    Directory of Open Access Journals (Sweden)

    E. Dinar

    2006-01-01

    Full Text Available Atmospheric aerosols play significant roles in climatic related phenomena. Size, density and shape of particles affect their fluid-dynamic parameters which in turn dictate their transport and lifecycle. Moreover, density and shape are also related to particles' optical properties, influencing their regional and global radiative effects. In the present study we have measured and compared the effective densities of humic like substances (HULIS extracted from smoke and pollution aerosol particles to those of molecular weight-fractionated aquatic and terrestrial Humic Substances (HS. The effective density was measured by comparing the electro mobility and vacuum aerodynamic diameter of aerosol particles composed of these compounds. Characterization of chemical parameters such as molecular weight, aromaticity and elemental composition allow us to test how they affect the effective density of these important environmental macromolecules. It is suggested that atmospheric aging processes increase the effective density of HULIS due to oxidation, while packing due to the aromatic moieties plays important role in determining the density of the aquatic HS substances.

  9. Metal-modified silica adsorbents for removal of humic substances in water.

    Science.gov (United States)

    Moriguchi, Takeshi; Yano, Kazuyuki; Tahara, Muneaki; Yaguchi, Kazuhiko

    2005-03-15

    As novel adsorbents for humic substances, Fe-, Mg-, and Ca-modified silica gels SiO(2)Fe, SiO(2)Mg, and SiO(2)Ca were prepared, and their adsorbabilities to humic and fulvic acids were evaluated in water at 25 degrees C for 20 h. Among these adsorbents, SiO(2)Fe indicated the highest adsorbability, in which removing humic substances in water was accomplished to 80-97%. By calcination at 600 degrees C and washing with water, adsorbabilities of the silica adsorbents deteriorated except for the case of calcination of SiO(2)Ca. This is due to changing metal modification structures and losing chlorine, judging from elemental analysis, TG-DTA, and XPS. Especially, the modifier Fe was tightly fixed on the silica surface of SiO(2)Fe, since the metal content was almost constant even after the calcination and water washing unlike the other adsorbents. Therefore, we found that SiO(2)Fe is the most useful adsorbent among the silica adsorbents and that its modification structure is composed of SiOFe, FeCl, and FeOH. In addition, the adsorption mechanism is explained by an interaction between Fe and humic substance molecule having carboxylate and phenolate groups, accompanied with anion exchange of chloride ion Cl(-) for the humic substance molecule via the silica pores. SiO(2)Fe may be applied to an adsorbent alternative for charcoal in water purification plants, and the used SiO(2)Fe may be further reused as a fertilizer since humic substances have plant-glowing ability and silica strengthens plant parts.

  10. Enzymatic (?) activity associated with humic substances in deep sediments from the Cariaco Trench and Walvis Ridge

    Science.gov (United States)

    Nissenbaum, Arie; Serban, Andrei

    1987-02-01

    Sediment samples from the Cariaco Trench (DSDP Leg 15) and the Walvis Ridge (DSDP Leg 65) ranging in age from Holocene to Upper Miocene (approximately 8,000,000 years BP) and in depth from 5 to 258 m were extracted with basic sodium pyrophosphate and the extract analyzed for enzymic activity. Since no dehydrogenase, alkaline phosphatase or esterase activity was found, it is estimated from these data that the maximum bacterial population does not exceed 10 3 cells per gram dry sediment. Peroxidase activity was, however, found in most samples: this showed marked dependence on the humic substance concentration (expressed as percent of the organic carbon content) and increased with depth at a rate of 33 units per meter. To explain this observation, we favor an hypothesis based on the presence of active humic-enzyme association. The humic substances absorb and stabilize peroxidase which is liberated throughout the sediment column by lysis of cells. The association of the enzyme with the humic substances protects it from biodegradation and denaturation. This hypothesis agrees with laboratory experiments which show the enhanced stability of humic-enzyme complexes towards degradation by biological, chemical and thermal effects.

  11. Seminars

    OpenAIRE

    Aguilar Pérez, Marta

    2016-01-01

    This chapter aims to unravel the complex array of academic events, called seminars, drawing on the literature and research carried out in the past decades. As seminar tends to be an umbrella term encompassing different realities, two main strands of research are identified. In fact, two different genres can be said to exist even though they are both academic and research-process genres (Swales 1990, 2004; Weissberg 1993). The first is strictly speaking a pedagogic genre that mainly involves s...

  12. Covalent binding of aniline to humic substances. 1. Kinetic studies

    Science.gov (United States)

    Weber, E.J.; Spidle, D.L.; Thorn, K.A.

    1996-01-01

    The reaction kinetics for the covalent binding of aniline with reconstituted IHSS humic and fulvic acids, unfractionated DOM isolated from Suwannee River water, and whole samples of Suwannee River water have been investigated. The reaction kinetics in each of these systems can be adequately described by a simple second-order rate expression. The effect of varying the initial concentration of aniline on reaction kinetics suggested that approximately 10% of the covalent binding sites associated with Suwannee River fulvic acid are highly reactive sites that are quickly saturated. Based on the kinetic parameters determined for the binding of aniline with the Suwannee River fulvic and humic acid isolates, it was estimated that 50% of the aniline concentration decrease in a Suwannee River water sample could be attributed to reaction with the fulvic and humic acid components of the whole water sample. Studies with Suwannee River fulvic acid demonstrated that the rate of binding decreased with decreasing pH, which parallels the decrease in the effective concentration of the neutral form, or reactive nucleophilic species of aniline. The covalent binding of aniline with Suwannee River fulvic acid was inhibited by prior treatment of the fulvic acid with hydrogen sulfide, sodium borohydride, or hydroxylamine. These observations are consistent with a reaction pathway involving nucleophilic addition of aniline to carbonyl moieties present in the fulvic acid.

  13. Electrochemical removal and recovery of humic-like substances from wastewater

    NARCIS (Netherlands)

    Kliaugaitė, Daina; Yasadi, Kamuran; Euverink, Gert-Jan; Bijmans, Martijn F.M.; Racys, Viktoras

    2013-01-01

    The secondary effluent from paper and food industry wastewater still contains a high chemical oxygen demand and color intensity caused by the presence of difficult degradable organic compounds. These compounds are mostly humic-like substances. This study focused on two promising electrochemical

  14. Electrospray ionization mass spectrometry of terrestrial humic substances and their size fractions

    Energy Technology Data Exchange (ETDEWEB)

    Piccolo, A. [Dipartimento di Scienze del Suolo, della Pianta e dell' Ambiente, Universita di Napoli Federico II, Via Universita 100, 80055, Portici (Italy); Spiteller, M. [Institute of Environmental Research (INFU), University of Dortmund, Otto-Hahn-Strasse 6, 44227, Dortmund (Germany)

    2003-11-01

    Electrospray ionization mass spectrometry (ESI-MS) was used to evaluate the average molecular mass of terrestrial humic substances, such as humic (HA) and fulvic (FA) acids from a soil, and humic acid from a lignite (NDL). Their ESI mass spectra, by direct infusion, gave average molecular masses comparable to those previously obtained for aquatic humic materials. The soil HA and FA were further separated in size-fractions by preparative high performance size exclusion chromatography (HPSEC) and analyzed with ESI-MS by both direct infusion and a further on-line analytical HPSEC. Unexpectedly, their average molecular mass was only slightly less than for the bulk sample and, despite different nominal molecular size, did not substantially vary among size-fractions. The values increased significantly (up to around 1200 Da) after on-line analytical HPSEC for the HA bulk sample, at both pH 8 and 4, and for the HA size-fractions when pH was reduced from 8 to 4. It was noticed that HA size-fractions at pH 8 were separated by on-line HPSEC in further peaks showing average masses which progressively increased with elution volume. Furthermore, when the HA and NDL bulk samples were sequentially ultracentrifuged at increasing rotational speed, their supernatants showed mass values which were larger than bulk samples and increased with rotational speed. These variations in mass values indicate that the electrospray ionization is dependent on the composition of the humic molecular mixtures and increases when their heterogeneity is progressively reduced. It is suggested that the dominance of hydrophobic compounds in humic supramolecular associations may inhibit the electrospray ionization of hydrophilic components. Our results show that ESI-MS is reasonably applicable to humic substances only after an extensive reduction of their chemical complexity. (orig.)

  15. The Dynamics Surface Adsorption of Fe Oxide-Humic Substance Complexes

    OpenAIRE

    Fahmi, Arifin

    2011-01-01

    Iron (Fe) oxide is the most abundant metallic oxides in the soils, it is highly reactive so that it has a huge influence on the dynamics of chemical balance in the soil both in terms soil fertility and environmental decontamination from toxic metal. Naturally, the surface of Fe oxide is coated with organic substances in the form of complexes compound, this condition may influence on its reactivity and retention capacity to ions in the soil solution. The presence of humic substances may increa...

  16. Double-walled carbon nanotubes suspending by natural active substances (saponins and humic acids

    Directory of Open Access Journals (Sweden)

    Zafour-Hadj-Ziane A.

    2013-09-01

    Full Text Available Carbon nanotubes (CNTs discovered over the past fifteen years are very interesting materials because of their structural, mechanical, chemical and electronic properties. However, their poor dispersion after synthesis constitutes a real obstacle to their use in varied fields. To respond to a topical issue, we proposed a new concept based on the use of natural active substances such a saponins; biosurfactant extracted from the tree Sapindus Mukorossiand humic acids. The results showed that for a concentration of 1.5 mg/l of saponin and 5 mg/l of humic acids, the stable suspensions were obtained; the zeta potential measurements have justified these results.

  17. Mechanisms regulating bioavailability of phenanthrene sorbed on a peat soil-origin humic substance.

    Science.gov (United States)

    Yang, Yu; Shu, Liang; Wang, Xilong; Xing, Baoshan; Tao, Shu

    2012-07-01

    The organic matter-mineral complex plays an important role in regulating the fate of hydrophobic organic compounds (HOCs) in the environment. In the present study, the authors investigated the microbial bioavailability of phenanthrene (PHE) sorbed on the original and demineralized humic acids (HAs) and humin (HM) that were sequentially extracted from a peat soil. Demineralization treatment dramatically decreased the 720-h mineralized percentage of HM-sorbed PHE from 42.5 ± 2.6% to 3.4 ± 1.3%, whereas the influence of this treatment on the biodegradability of HA-associated PHE was much lower. Degradation kinetics of HA- and HM-sorbed PHE showed that its initial degradation rate was negatively correlated with the aromatic carbon content of humic substances (p<0.05). This was attributed to the strong interactions between PHE and the aromatic components of humic substances, which hampered its release and subsequent biodegradation. The 720-h mineralized percentage of PHE was inversely correlated with the estimated thickness of the organic matter layer at the surfaces of HAs and HMs. Therefore, in a relatively long term, diffusion of PHE within the organic matter layer could be an important factor that may limit the bioavailability of PHE to bacteria. Results of the present study highlight the molecular-scaled mechanisms governing bioavailability of PHE sorbed on humic substances. Copyright © 2012 SETAC.

  18. Nitrite fixation by humic substances: Nitrogen-15 nuclear magnetic resonance evidence for potential intermediates in chemodenitrification

    Science.gov (United States)

    Thorn, K.A.; Mikita, M.A.

    2000-01-01

    Studies have suggested that NO2/-, produced during nitrification and denitrification, can become incorporated into soil organic matter and, in one of the processes associated with chemodenitrification, react with organic matter to form trace N gases, including N2O. To gain an understanding of the nitrosation chemistry on a molecular level, soil and aquatic humic substances were reacted with 15N-labeled NaNO2, and analyzed by liquid phase 15N and 13C nuclear magnetic resonance (NMR). The International Humic Substances Society (IHSS) Pahokee peat and peat humic acid were also reacted with Na15NO2 and analyzed by solid-state 15N NMR. In Suwannee River, Armadale, and Laurentian fulvic acids, phenolic rings and activated methylene groups underwent nitrosation to form nitrosophenols (quinone monoximes) and ketoximes, respectively. The oximes underwent Beckmann rearrangements to 2??amides, and Beckmann fragmentations to nitriles. The nitriles in turn underwent hydrolysis to 1??amides. Peaks tentatively identified as imine, indophenol, or azoxybenzene nitrogens were clearly present in spectra of samples nitrosated at pH 6 but diminished at pH 3. The 15N NMR spectrum of the peat humic acid exhibited peaks corresponding with N-nitroso groups in addition to nitrosophenols, ketoximes, and secondary Beckmann reaction products. Formation of N-nitroso groups was more significant in the whole peat compared with the peat humic acid. Carbon-13 NMR analyses also indicated the occurrence of nitrosative demethoxylation in peat and soil humic acids. Reaction of 15N-NH3 fixated fulvic acid with unlabeled NO2/- resulted in nitrosative deamination of aminohydroquinone N, suggesting a previously unrecognized pathway for production of N2 gas in soils fertilized with NH3.Studies have suggested that NO2-, produced during nitrification and denitrification, can become incorporated into soil organic matter and, in one of the processes associated with chemodenitrification, react with organic

  19. Condition of copper and organic matter in the soil contaminated with metal remediation of humic substances.

    Science.gov (United States)

    Kolchanova, Kseniia; Barsova, Natalia; Motuzova, Galina; Stepanov, Andrey; Karpukhin, Mikhail

    2017-04-01

    The aim of this study was to investigate the forms of copper and transformation of organic matter in the soil under the influence of humic substances (potassium humate, which was obtained from coal). The object of research was the top layer of soil model field experience. Field experiments were carried out in 10-liter plastic containers.The upper layers were constructed artificially as mixture of loam, sand and peat. Below it was a layer of loam, then gravel and under it we installed lysimeters. The experiment was conducted in 3 settings: 1) control, 2) control + Cu, and 3) control + Cu + potassium humate . Copper was deposited into upper layer at soil column construction as dry powder (CuSO4*5H2O), which is 1000mg per kg. Humic substance was introduced on surface as liquid form. The focus was the state of the copper and organic matter of solid and liquid phase. In the solid phase pH, carbon content, the molecular-mass distributions for the organic matter, total (HNO3 conc.+ H2O2; decomposition in a microwave oven) and acid-soluble (1H HNO3) copper content, sequential extraction of copper (1 M MgCl2, acetate buffer pH 4,8 (AAB), 1% EDTA) were determined. For liquid phase characteristics aqueous extract was obtained and identified therein: pH, total activity and copper content and water-soluble organic matter(WOM) amphiphilic properties. The introduction of copper is accompanied by a decrease in pH in soils from 7 to 6,3. The introduction of the humic substance softens this effect. Introducing humic preparation gives an increase in carbon at 0.5%. HS and copper has no significant effect on the molecular-mass distribution of solid organic matter. Only about 4% introduced copper accounted for the exchangeable form (MgCl2) for the variant only copper contaminated. Copper, mainly precipitated as hydroxides, moved in an AAB extract. And compared with the exchangeable forms its quantity increases by 10 times. Still more copper goes into an extract of EDTA, about half of

  20. Monitoring transitory profiles of leachate humic substances in landfill aeration reactors in mesophilic and thermophilic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Huanhuan [Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, 637141 (Singapore); School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 (Singapore); Yin, Ke; Ge, Liya; Giannis, Apostolos [Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, 637141 (Singapore); Chuan, Valerie W.L. [School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 (Singapore); Wang, Jing-Yuan, E-mail: JYWANG@ntu.edu.sg [Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, 637141 (Singapore); School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 (Singapore)

    2015-04-28

    Highlights: • Polymerization and condensation of humic substances (HS) were enhanced by aeration. • Carboxylic group was enriched in HS by aeration presenting improved hydrophilicity. • Mobility of humic acid, as a result was enhanced by aeration especially in young landfill. • Waste age plays an important role in leachate management during aeration. - Abstract: The presence of humic substances (HS) in landfill leachate is of great interest because of their structural stability and potential toxicity. This study examined the effects of temperature and waste age on the transformation of HS during in situ aeration of bioreactor landfills. By establishing aerobic conditions, dissolved organic carbon (DOC) rapidly accumulated in the bioreactor leachate. Fractional analysis showed that the elevated concentration of humic acids (HAs) was primarily responsible for the increment of leachate strength. Further structural characterization indicated that the molecular weight (MW) and aromacity of HS were enhanced by aeration in conjunction with thermophilic temperature. Interestingly, elevation of HAs concentration was not observed in the aeration reactor with a prolonged waste age, as the mobility of HAs was lowered by the high MW derived from extended waste age. Based on these results, aeration may be more favorable in aged landfills, since dissolution of HAs could be minimized by the evolution to larger MW compared to young landfills. Moreover, increased operation temperature during aeration likely offers benefits for the rapid maturation of HS.

  1. SPECTROSCOPIC STUDY OF HUMIC SUBSTANCES EXTRACTED FROM WATER, SOIL AND SEDIMENT SAMPLES OF THE PATOS LAKE, MS, BRAZIL

    Directory of Open Access Journals (Sweden)

    Júlio César R Azevedo, Mariana Carolina Teixeira e Jorge Nozaki

    2006-06-01

    Full Text Available Humic substances (HSs were extracted from samples collected in 4 areas of sediment, water and soil from Patos´ lake - MS. The humic substances from the water were extracted according to Thurman and Malcolm methods (1981 and, those from sediment and soil were extracted as proposed by the International Society of Humic Substances (ISHS. The following spectroscopic techniques were performed in this study: ultraviolet and visible (UV-Vis and fluorescence emission. The effects of ambient factors as concentration and variations of pH in fluorescence emission of humic substances (fulvic and humic acids were evaluated. It was observed that the UV-Vis technique and the intensity of emitted fluorescence from humic substances extracted from water has shown linear correlation with the variation of fulvic acid (7.3 the 35.5 mg L-1 and of humic acid (4.8 the 23.9 mg L-1 concentrations, considering just dissolved organic carbon. However, for pH variation (acid, neutral and alkaline media significant variations were not observed in both, UV-Vis and fluorescence emission techniques.

  2. Effect of thermo-tolerant actinomycetes inoculation on cellulose degradation and the formation of humic substances during composting.

    Science.gov (United States)

    Zhao, Yi; Zhao, Yue; Zhang, Zhechao; Wei, Yuquan; Wang, Huan; Lu, Qian; Li, Yanjie; Wei, Zimin

    2017-10-01

    The inoculum containing four cellulolytic thermophilic actinomycetes was screened from compost samples, and was inoculated into co-composting during different inoculation phases. The effect of different inoculation phases on cellulose degradation, humic substances formation and the relationship between inoculation and physical-chemical parameters was determined. The results revealed that inoculation at different phases of composting improved cellulase activities, accelerated the degradation of cellulose, increased the content of humic substances and influenced the structure of actinomycetic community, but there were significant differences between different inoculation phases. Redundancy analysis showed that the different inoculation phases had different impacts on the relationship between exogenous actinobacteria and physical-chemical parameters. Therefore, based on the promoting effort of inoculation in thermophilic phase of composting for the formation of humic substances, we suggested an optimized inoculation strategy to increase the content of humic substances, alleviate CO 2 emission during composting. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Speciation of Aquatic Heavy Metals in Humic Substances by$^{111m}$Cd/$^{199m}$Hg-TDPAC

    CERN Multimedia

    2002-01-01

    Humic substances are ubiquitous in waters and soils and act as complexing agents for different heavy metals, e.g. Cd, Hg. Toxicity, reactivity, fixation and migration are therefore strongly influenced by the interactions between heavy metals and humic substances. Humic substances derive from postmortal materials such as rotten plants, have dark colours and usually a molecular weight between 500 and 10~000 Dalton. Complex formation studies with different heavy metal ions indicate at least two different kinds of metal sites. Usually, these studies are restricted to heavy metal concentrations 2 to 3 orders of magnitude higher than the natural heavy metal abundance (i.e. 10$^{-10}$ molar). This serious limitation can be overcome by the use of suitable radiosotope techniques capable of metal speciation at extreme sensitivity levels such as TDPAC (Time Differential Perturbed Angular Correlation of~$\\gamma$-rays). Thus, we studied the interaction of heavy metals with humic substances by monitoring the nuclear quadru...

  4. Comparative study of the efficacy of chemically and biologically extracted humic substances from various materials on the development of Poinsettia.

    Science.gov (United States)

    Georgieva, Teodora; Metodieva, Tsvetelina; Again, Nadia; Angelova, Gergana; Popova, Todorka; Chakalov, Konstantin; Savov, Valentin

    2017-04-01

    There is a lot of research proving the positive influence of humic substances on the development of plants in combination with soil isolates such as Pseudomonas and Bacillus. Humic substances obtained by chemical extraction and biosolubilization of various sources of organic materials were tested for their effect on the growth of Poinsettia (Euphorbia pulcherrima) cultivar „Mirat red". The test included the following variants: 1. Humic substances chemically extracted from "Humintech" leonardite (Ht); 2. Humic substances obtained from "Humintech" leonardite by biosolubilization with Pseudomonas putida (Pp) and Bacillus pasteurii (Bp) (Ht Bp Pp); 3. Humic substances chemically extracted from "Sachalin" leonardite; 4. Humic substances obtained from "Sachalin" leonardite by biosolubilization with Pseudomonas putida (Pp) and Bacillus pasteurii (Bp) (Sachalin Bp Pp); 5. Fulvic substances exracted after biosolubilization of "Staniantsy" lignite with Pseudomonas putida (Pp) and Bacillus pasteurii (Bp) (FB Plantagra); 6. Humic substances exracted after biosolubilization of "Staniantsy" lignite with Pseudomonas putida (Pp) and Bacillus pasteurii (Bp) (Lignohumate); 7. Biohumax - commercial product of "Project Studio" EOOD, Varna Bulgaria; 8.Vermicompost inoculated with Pseudomonas putida and Bacillus pasteurii (Strong BG); 9. Control - Nutrient solution (background of nutrition). The test results indicate that as a result of microbial activity active bacterial compounds are probably present in the composition of the extracted humates, thus affecting the formation of red leaves.The application of all tested substances results in red leaves area increase of treated plants compared to the control plants, except the humates chemically extracted from Humintech leonardite. The ration between humic and fulvic acids determines the effect on the treated plants. The biosolubilized preparations contain more fulvic acids. Plants treated with them form up to three times more

  5. The influence of humic substance on Cd accumulation of phytostabilizer Athyrium wardii (Hook.) grown in Cd-contaminated soils.

    Science.gov (United States)

    Zhan, Juan; Li, Tingxuan; Yu, Haiying; Zhang, Xizhou; Zhao, Li

    2016-09-01

    The application of organic amendments into heavy metal contaminated soil is considered as an environmentally friendly technique to promote the potential of phytoremediation. A pot experiment was carried out to evaluate the effect of humic substances on growth, cadmium (Cd) accumulation and phytostabilization potential of the mining ecotype (ME) and the corresponding non-mining ecotype (NME) of Athyrium wardii (Hook.) grown in Cd-contaminated soils. The addition of the humic substances demonstrated great promotion for the growth and Cd uptake of ME. Both plant biomass and Cd concentration significantly increased with the increasing application of the humic substances up to 100 g kg(-1), beyond which no significant change of underground part biomass and Cd concentrations in underground part of A. wardii was observed. The maximum Cd concentration in underground part of ME was 180 mg kg(-1) when 150 g kg(-1) humic substances were applied. The ME showed greater Cd accumulation capability in underground part (0.47-0.68 mg plant(-1)) than that of NME (0.27-0.45 mg plant(-1)). Increasing bioaccumulation coefficient (BCF) values of A. wardii was observed with increasing application of the humic substances. The BCF values of ME were higher than those of NME. However, the use of the humic substances exhibited little impact on translocation factors (TFs) of ME, and the TF values of ME were less than NME. Furthermore, the application of the humic substances improved the remediation factors (RFs) of A. wardii. The RF values in underground part of ME ranging from 0.73 to 0.91 % were apparently higher than those of NME. These results indicated that the humic substances can be a potential candidate for enhancing the phytostabilization of A. wardii grown in Cd-contaminated soils.

  6. Effect of Sediment Humic Substances on Sorption of Selected Endocrine Disruptors

    Energy Technology Data Exchange (ETDEWEB)

    Sun, W. L., E-mail: sunweiling@iee.pku.edu.cn; Ni, J. R.; Liu, T. T. [The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Department of Environmental Engineering, Peking University (China)

    2006-12-15

    Characterizing sorption processes is essential to understand the environmental distribution and toxicity potential of endocrine disruptors in terrestrial and aquatic systems. The sorption behaviors of three endocrine disruptors (bisphenol A (BPA), 17{beta}-estradiol (E2), and 17{alpha}-ethynylestradiol (EE2)) on sediments were investigated using batch techniques. Samples were taken from some representative reaches in several major Chinese rivers. More attention has been paid to the effect of sediment organic components on the sorption of BPA, E2, and EE2. The results show that the sediment organic carbon-normalized partition coefficients (K{sub oc}(sed)) for three endocrine disruptors are in the order of EE2 > E2 > BPA, which corresponds to the octanol-water partitioning coefficients (logK{sub ow}) of the compounds. Moreover, the K{sub oc} values for humic substances (K{sub oc}(hs)) are comparable with the K{sub oc}(sed) values and highly dependent on the physico-chemical properties of humic substances in sediments. The UV absorptivity at 272 nm (A{sub 272}), which suggests the abundance of aromatic rings in humic substance structure, correlates well with the K{sub oc}(hs) values. In addition, the infrared spectra of the humic substances extracted from sediments show four strong bands centered at 3,400 cm{sup -1}, 1,625 cm{sup -1}, 1,390 cm{sup -1}, and 1,025 cm{sup -1}. The K{sub oc}(hs) values have a positive linear relation with the peak area ratio for peak at 1,025 cm{sup -1} and a negative linear relation with the peak area ratio between peaks at 1,625 cm{sup -1} and 1,025 cm{sup -1}. Hence, the hydrogen bonds play a critical role to the sorption of selected endocrine disruptors.

  7. Effects of molecular weight on the diffusion coefficient of aquatic dissolved organic matter and humic substances.

    Science.gov (United States)

    Balch, J; Guéguen, C

    2015-01-01

    In situ measurements of labile metal species using diffusive gradients in thin films (DGT) passive samplers are based on the diffusion rates of individual species. Although most studies have dealt with chemically isolated humic substances, the diffusion of dissolved organic matter (DOM) across the hydrogel is not well understood. In this study, the diffusion coefficient (D) and molecular weight (MW) of 11 aquatic DOM and 4 humic substances (HS) were determined. Natural, unaltered aquatic DOM was capable of diffusing across the diffusive gel membrane with D values ranging from 2.48×10(-6) to 5.31×10(-6) cm(2) s(-1). Humic substances had diffusion coefficient values ranging from 3.48×10(-6) to 6.05×10(-6) cm(2) s(-1), congruent with previous studies. Molecular weight of aquatic DOM and HS samples (∼500-1750 Da) measured using asymmetrical flow field-flow fractionation (AF4) strongly influenced D, with larger molecular weight DOM having lower D values. No noticeable changes in DOM size properties were observed during the diffusion process, suggesting that DOM remains intact following diffusion across the diffusive gel. The influence of molecular weight on DOM mobility will assist in further understanding and development of the DGT technique and the uptake and mobility of contaminants associated with DOM in aquatic environments. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. QUALITY OF GROUNDWATER AND AQUATIC HUMIC SUBSTANCES FROM MAIN RESERVOIRE OF GROUND WATER No. 333

    Directory of Open Access Journals (Sweden)

    Izabella Pisarek

    2015-11-01

    Full Text Available The conducted research included the estimation of the quality of groundwater from the Main Reservoir of Ground Water No. 333 area in Opole District, Poland. The groundwater in the analyzed region shows high diversity in quality. The main threat for the quality of water in this region is the human household activity. The main pollutants of groundwater are: dissolved phosphorus, nitrate and ammonium. The quality and quantity of dissolved humic substances in groundwater were also investigated. The results showed that the contents of water-extractable organic carbon varied. Presently, the analyzed groundwater is characterized by large differences in dissolved forms of organic carbon. During migration of the soil solution through the soil profile to groundwater, dissolved humic substances undergo qualitative and quantitative changes. Correlation analysis between the quantity of carbon in soil and aquatic humic substances, especially fulvic acids, indicates the possibility of their translocation in soil profiles and their transformation and migration to groundwater. This conclusion can be confirmed by FT-IR-analysis.

  9. The influence of copper on tebuconazole sorption onto soils, humic substances, and ferrihydrite.

    Science.gov (United States)

    Čadková, Eva; Komárek, Michael; Kaliszová, Regina; Száková, Jiřina; Vaněk, Aleš; Bordas, François; Bollinger, Jean-Claude

    2013-06-01

    The aim of this study is to investigate how the presence of Cu influences tebuconazole (Teb) sorption onto contrasting soil types and two important constituents of the soil sorption complex: hydrated Fe oxide and humic substances. Tebuconazole was used in commercial form and as an analytical-grade chemical at different Teb/Cu molar ratios (1:4, 1:1, 4:1, and Teb alone). Increased Cu concentrations had a positive effect on tebuconazole sorption onto most soils and humic substances, probably as a result of Cu-Teb tertiary complexes on the soil surfaces. Tebuconazole sorption increased in the following order of different Teb/Cu ratios 1:4>1:1>4:1>without Cu addition, with the only exception for the Leptosol and ferrihydrite. The highest K f value was observed for humic substances followed by ferrihydrite, the Cambisol, the Arenosol, and the Leptosol. The sorption of analytical-grade tebuconazole onto all matrices was lower, but the addition of Cu supported again tebuconazole sorption. The Teb/Cu ratio with the highest Cu addition (1:4) exhibited the highest K f values in all matrices with the exception of ferrihydrite. The differences in tebuconazole sorption can be attributed to the additives present in the commercial product. This work proved the importance of soil characteristics and composition of the commercially available pesticides together with the presence of Cu on the behavior of tebuconazole in soils.

  10. Humic substances elemental composition of selected taiga and tundra soils from Russian European North-East

    Directory of Open Access Journals (Sweden)

    Lodygin Evgeny

    2017-06-01

    Full Text Available Soils of Russian European North were investigated in terms of stability and quality of organic matter as well as in terms of soils organic matter elemental composi­tion. Therefore, soil humic acids (HAs, extracted from soils of different natural zones of Russian North-East were studied to characterize the degree of soil organic matter stabilization along a zonal gradient. HAs were extracted from soil of different zonal environments of the Komi Republic: south, middle and north taiga as well as south tundra. Data on elemental composition of humic acids and fulvic acids (FAs extracted from different soil types were obtained to assess humus formation mechanisms in the soils of taiga and tundra of the European North-East of Russia. The specificity of HAs elemental composition are discussed in relation to environmental conditions. The higher moisture degree of taiga soils results in the higher H/C ratio in humic substances. This reflects the reduced microbiologic activity in Albeluvisols sods and subsequent conser­vation of carbohydrate and amino acid fragments in HAs. HAs of tundra soils, shows the H/C values decreasing within the depth of the soils, which reflects increasing of aromatic compounds in HA structure of mineral soil horizons. FAs were more oxidized and contains less carbon while compared with the HAs. Humic acids, extracted from soil of different polar and boreal environments differ in terms of elemental composition winch reflects the climatic and hydrological regimes of humification.

  11. Comparative characterization of humic substances extracted from freshwater and peat of different apparent molecular sizes

    Directory of Open Access Journals (Sweden)

    Eliane Sloboda Rigobello

    2017-09-01

    Full Text Available This paper compares the structural characteristics of aquatic humic substances (AHS with humic substances from peat (HSP through different analytical techniques, including elemental analysis, solid state 13C cross polarization/magic-angle-spinning nuclear magnetic resonance spectroscopy (13C CP-MAS NMR, ultraviolet/visible (UV/Vis spectroscopy and Fourier transform infrared (FTIR spectroscopy and total organic carbon (TOC. The AHS were extracted from water collected in a tributary of the Itapanhaú River (Bertioga/SP using XAD 8 resin, and the HSP were extracted from peat collected in the Mogi Guaçu River bank (Luis Antonio/SP with a KOH solution. After dialysis, both AHS and HSP extracts were filtered in membrane of 0.45 µm pore size (Fraction F1: < 0.45 µm and fractioned by ultrafiltration in different apparent molecular sizes (AMS (F2: 100 kDa-0.45 μm; F3: 30 kDa-100 kDa and F4: < 30 kDa. The extracts with the lowest AMS (F3 and F4 showed a higher number of aliphatic carbons than aromatic carbons, a higher concentration of groups containing oxygen and a higher percentage of fulvic acids (FA than humic acids (HA for both AHS and HSP. However, the AHS presented higher FA than HA content in relation to the HSP and distinct structural properties.

  12. Root growth of tomato seedlings intensified by humic substances from peat bogs

    Directory of Open Access Journals (Sweden)

    Alexandre Christofaro Silva

    2011-10-01

    Full Text Available Peats are an important reserve of humified carbon in terrestrial ecosystems. The interest in the use of humic substances as plant growth promoters is continuously increasing. The objective of this study was to evaluate the bioactivity of alkaline soluble humic substances (HS, humic (HA and fulvic acids (FA isolated from peats with different decomposition stages of organic matter (sapric, fibric and hemic in the Serra do Espinhaço Meridional, state of Minas Gerais. Dose-response curves were established for the number of lateral roots growing from the main plant axis of tomato seedlings. The bioactivity of HA was greatest (highest response in lateral roots at lowest concentration while FA did not intensify root growth. Both HS and HA stimulated root hair formation. At low concentrations, HS and HA induced root hair formation near the root cap, a typical hormonal imbalance effect in plants. Transgenic tomato with reporter gene DR5::GUS allowed the observation that the auxin-related signalling pathway was involved in root growth promotion by HA.

  13. Covalent binding of aniline to humic substances. 2. 15N NMR studies of nucleophilic addition reactions

    Science.gov (United States)

    Thorn, K.A.; Pettigrew, P.J.; Goldenberg, W.S.; Weber, E.J.

    1996-01-01

    Aromatic amines are known to undergo covalent binding with humic substances in the environment. Although previous studies have examined reaction conditions and proposed mechanisms, there has been no direct spectroscopic evidence for the covalent binding of the amines to the functional groups in humic substances. In order to further elucidate the reaction mechanisms, the Suwannee River and IHSS soil fulvic and humic acids were reacted with 15N-labeled aniline at pH 6 and analyzed using 15N NMR spectrometry. Aniline underwent nucleophilic addition reactions with the quinone and other carbonyl groups in the samples and became incorporated in the form of anilinohydroquinone, anilinoquinone, anilide, imine, and heterocyclic nitrogen, the latter comprising 50% or more of the bound amine. The anilide and anilinohydroquinone nitrogens were determined to be susceptible to chemical exchange by ammonia. In the case of Suwannee River fulvic acid, reaction under anoxic conditions and pretreatment with sodium borohydride or hydroxylamine prior to reaction under oxic conditions resulted in a decrease in the proportion of anilinohydroquinone nitrogen incorporated. The relative decrease in the incorporation of anilinohydroquinone nitrogen with respect to anilinoquinone nitrogen under anoxic conditions suggested that inter- or intramolecular redox reactions accompanied the nucleophilic addition reactions.

  14. Influence of biochar addition on the humic substances of composting manures.

    Science.gov (United States)

    Jindo, Keiji; Sonoki, Tomonori; Matsumoto, Kazuhiro; Canellas, Luciano; Roig, Asunción; Sanchez-Monedero, Miguel A

    2016-03-01

    Application of biochar (10% v/v) to a manure composting matrix was investigated to evaluate its effect on the chemical composition of humic substances during the composting process. The characteristics of the humic acid (HA) and fulvic acid (FA) fractions were analyzed in compost mixtures originating from two different manures (poultry manure (PM) and cow manure (CM)). The C contents of HA and FA from the manure compost/biochar blends (PM+B and CM+B) were higher than those from PM and CM, with an enhanced recalcitrant fraction, as determined by thermogravimetric analysis. Spectroscopic analysis showed that enrichment of aromatic-C and carboxylic-C occurred in the FA fractions of PM+B and CM+B to a greater extent than in PM and CM. Biochar addition into the composting mixture improved the final compost quality, especially for the light humified fraction (FA). Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Investigating Nitrate-Dependent Humic Substance Oxidation and In-Service K-12 Teachers' Understanding of Microbiology

    Science.gov (United States)

    Jones, Nastassia N.

    2011-01-01

    Humic substances (HS) are the humified portions of totally decomposed soil organic matter that are ubiquitous in nature. Although these substances have been studied for more than 200 years, neither their metabolic capabilities nor a specific chemical structure has yet to be determined. HS have been studied as a carbon source in many environments…

  16. Calculation of molecular weights of humic substances from colligative data: Application to aquatic humus and its molecular size fractions

    Science.gov (United States)

    Reuter, J. H.; Perdue, E. M.

    1981-11-01

    A rigorous mathematical expression for the dependence of colligative properties on acid dissociation of water soluble humic substances is presented. New data for number average molecular weights of a river derived humic material and its gel permeation Chromatographic fractions are compared with M¯n values obtained by a reevaluation of previously published experimental observations on soil and water fulvic acids. The results reveal a remarkable similarity of fulvic acids from widely different sources with respect to number-average molecular weight.

  17. Enzymatic Transformation and Bonding of Sulfonamide Antibiotics to Model Humic Substances

    Directory of Open Access Journals (Sweden)

    J. Schwarz

    2015-01-01

    Full Text Available Sulfonamides are consumed as pharmaceutical antibiotics and reach agricultural soils with excreta used as fertilizer. Subsequently, nonextractable residues rapidly form in soil, which has been researched in a couple of studies. To further elucidate conditions, strength, and mechanisms of the fixation to soil humic substances, three selected sulfonamides were investigated using the biochemical oligomerization of substituted phenols as a model for the humification process. Catechol, guaiacol, and vanillin were enzymatically reacted using laccase from Trametes versicolor. In the presence of the substituted phenols alone, the concentration of sulfonamides decreased. This decrease was even more pronounced when additional laccase was present. Upon the enzymatic oligomerization of the substituted phenols to a humic-like structure the sulfonamides were sorbed, transformed, sequestered, and nonextractable bound. Sulfonamides were transformed depending on their molecular properties. Fractions of different bonding strength were determined using a sequential extraction procedure. Isolated nonextractable products were analyzed by chromatographic, spectroscopic, and calorimetric methods to identify coupling and bonding mechanisms of the sulfonamides. Differential scanning calorimetry measurements suggested cross-linking of such incorporated sulfonamides in humic oligomers. Nuclear magnetic resonance spectroscopy measurements showed clear differences between the vanillin-sulfapyridine oligomer and the parent sulfapyridine indicating bound residue formation through covalent binding.

  18. Applied Technology on Influence of Humic Substances on Fertilizer, Water-use Efficiency and Soil Health

    Science.gov (United States)

    Seyedbagheri, Mir

    2017-04-01

    In continuation of over 35 years of on-farm studies on soil organic matter from different humates (functional carbon) and compost, I have documented quantitative improvements in soil health and water-use efficiency. The ability of soil organic matter to bind water has become an important theme for research in past years. Research trials were established to evaluate the efficacy of different commercial functional carbon products derived from Leonardite (highly oxidized lignite) in crop production. In each of these trials, functional carbon (Humic and Fulvic acids) products were used in a randomized complete block design. The use of humic substances creates strong organo-mineral complexes (aggregation), chelation, as well as enhanced buffering capacities. We evaluated data from 3 fields and compared the results. Our observation and field demonstrations indicated there was a marked increase in water retention. Data from humic acid (HA) trials showed that different cropping systems responded differently to different products in relation to yield and quality. The functional carbon products used in the study seemed to enhance fertilizer and water-use efficiency by increasing complexation, chelation and buffering. The consistent use of good quality functional carbons in our replicated plots resulted in a yield increase from 6% to 30% over several decades.

  19. Interactions of mercury with different molecular weight fractions of humic substances in aquatic systems.

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, P.; Yao, K.M.; Chennuri, K.; Vudamala, K.; Babu, P.V.R.

    stream_size 6796 stream_content_type text/plain stream_name Environ_Earth_Sci_72_931s.pdf.txt stream_source_info Environ_Earth_Sci_72_931s.pdf.txt Content-Encoding UTF-8 Content-Type text/plain; charset=UTF-8 Author... version: Environ. Earth Sci., vol.72(3); 2014; 931–939 Supporting documents Interactions of mercury with different molecular weight fractions of humic substances in aquatic systems Parthasarathi Chakraborty1*, Koffi Marcellin Yao1,2, P.V. Raghunadh...

  20. Role of humic substances in the photodegradation of naproxen under simulated sunlight.

    Science.gov (United States)

    Chen, Yong; Liu, Lu; Su, Jing; Liang, Jianfeng; Wu, Bo; Zuo, Jiaolan; Zuo, Yuegang

    2017-11-01

    Humic substances (HS) including humic acid (HA) and fulvic acid (FA) are ubiquitous in the natural waters. Although numerous studies documented their role in photodegradation of organic pollutants, the competitive effects of photosensitization and light-screening of HS on the photodegradation of pollutants are not yet clear. In this work, the role of HS in the photodegradation of the pharmaceutical naproxen (NP) was studied under simulated sunlight. The direct photodegradation quantum yield of NP in deionized water was 2.1 × 10(-2), and the apparent quantum yields for photosensitized degradation of NP in the presence of FA and HA were 2.3 × 10(-4) and 2.6 × 10(-5), respectively. Both direct and photosensitized photodegradation decreased with increasing pH, consistent with the trend of singlet oxygen ((1)O2) reaction rate constants of NP. HA inhibited the photodegradation of naproxen thoroughly. In contrast, FA accelerated the photodegradation of NP at lower substrate concentration and light intensity, and vice versa. Direct photodegradation of NP declined sharply with spectral radiation attenuation of UV region, when HS-mediated photosensitization predominantly accounted for the photodegradation. The direct photodegradation was ascribed to decomposition of excited triplet state of naproxen ((3)NP(∗)) and self-sensitization effect involving (1)O2. The FA-mediated photodegradation was mainly attributed to (1)O2 oxidation in aerated solution. These findings are important for assessing the competitive effects of humic substances on the photodegradation of pollutants under various conditions in natural waters. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Improving Lowland Rice (O. sativa L. cv. MR219) Plant Growth Variables, Nutrients Uptake, and Nutrients Recovery Using Crude Humic Substances

    Science.gov (United States)

    Palanivell, Perumal; Ahmed, Osumanu Haruna; Ab Majid, Nik Muhamad; Jalloh, Mohamadu Boyie; Susilawati, Kasim

    2015-01-01

    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. PMID:25977938

  2. Liquid organomineral fertilizer containing humic substances on soybean grown under water stress

    Directory of Open Access Journals (Sweden)

    Marcelo R. V. Prado

    2016-05-01

    Full Text Available ABSTRACT This study evaluated the effect of an organomineral fertilizer enriched with humic substances on soybean grown under water stress. The experiment was performed in a greenhouse using a Red Latosol (Oxisol with adequate fertility as substrate, in which soybean plants were cultivated with and without water stress. The experimental design was randomized blocks, in a 2 x 5 factorial scheme (two moisture levels and five fertilizer doses: 0, 1, 2, 4 and 8 mL dm-3, totaling 10 treatments, with four replicates. The organomineral fertilizer was applied in the soil 21 days after plant emergence and the water regimes were established one week thereafter. The fertilizer was not able to attenuate the effects of water stress, reducing soybean grain yield by more than 50% compared with plants cultivated under no stress. Fertilizer doses caused positive response on soybean nutrition and grain yield and, under water stress condition, the most efficient dose was 5.4 mL dm-3. There were lower leaf concentrations of nitrogen, phosphorus and potassium and higher concentrations of sulfur in plants under stress. Humic substances favor the absorption of micronutrients.

  3. Comparison of analytical methods for Humic Like Substances (HULIS measurements in atmospheric particles

    Directory of Open Access Journals (Sweden)

    C. Baduel

    2009-08-01

    Full Text Available Humic-Like Substances (HULIS are a major contributor to the organic carbon in atmospheric aerosol. It would be necessary to standardize an analytical method that could be easily and routinely used for HULIS measurements. We present one of the first comparisons of two of the main methods in use to extract HULIS, using I a weak anion exchanger (DEAE and II the combination of two separation steps, one according to polarity (on C18 and the second according to acidity (with a strong anion exchanger SAX. The quantification is performed with a TOC analyzer, complemented by an investigation of the chemical structure of the extracted fractions by UV-Visible spectroscopy. The analytical performances of each method are determined and compared for humic substances standards. These methods are further applied to determine the water extractable HULIS (HULISWS and the 0.1 M NaOH alkaline extractable HULIS (HULIS T in atmospheric aerosol collected in an Alpine Valley during winter time. This comparison, although on a limited batch of samples shows that the simpler DEAE isolation procedure leads to higher recoveries and better reproducibility than the C18-SAX procedure, and might therefore be preferable.

  4. EVALUTION OF THE EFFICIENCY OF THE ADSORPTION PROCESS IN REMOVING HUMIC SUBSTANCES FROM WATER

    Directory of Open Access Journals (Sweden)

    Jadwiga Teresa Kaleta

    2017-08-01

    Full Text Available The paper presents the results of laboratory tests on possibilities to utilize active carbons produced in Poland (WD-ekstra, WG-12, WG-15, AG-5 and DTO for removing humic substances from water. The objective of the tests was to arrive to quantitative formulation of the adsorption process, as well as determine the effect of various factors on process course. Attempt was undertaken to solve the tasks set in the study purpose using model experimental setups. Model solution with humic substances in concentration of 20 mg/dm3. The processes of adsorption conducted in a batch mode, were best described by Freundlich isotherms. The adsorption capacity of tested active carbons was calculated on the basis of the isotherms. The flow conditions were created/realized by columnar filtration method. On the basis of obtained results, the breakthrough curves, so-called iso-planes, were prepared and served in turn to determine the adsorption capacities in flow conditions. The WD-extra (7,71 mg/g and DTO (7,40 mg/g carbons exhibited the highest values of adsorption capacities, as determined in both non-flow and flow conditions. The exit curves (iso-planes were also utilized to determine the mass penetration zone (the adsorption front height, as well as to calculate the rate of mass-exchange zone advance.

  5. Influence of humic substances on electrochemical degradation of trichloroethylene in limestone aquifers

    Science.gov (United States)

    Rajic, Ljiljana; Fallahpour, Noushin; Nazari, Roya; Alshawabkeh, Akram N.

    2015-01-01

    In this study we investigate the influence of humic substances (HS) on electrochemical transformation of trichloroethylene (TCE) in groundwater from limestone aquifers. A laboratory flow-through column with an electrochemical reactor that consists of a palladized iron foam cathode followed by a MMO anode was used to induce TCE electro-reduction in groundwater. Up to 82.9% TCE removal was achieved in the absence of HS. Presence of 1, 2, 5, and 10 mgTOC L−1 reduced TCE removal to 70.9%, 61.4%, 51.8% and 19.5%, respectively. The inverse correlation between HS content and TCE removal was linear. Total organic carbon (TOC), dissolved organic carbon (DOC) and absorption properties (A=254 nm, 365 nm and 436 nm) normalized to DOC, were monitored during treatment to understand the behavior and impacts of HS under electrochemical processes. Changes in all parameters occurred mainly after contact with the cathode, which implies that the HS are reacting either directly with electrons from the cathode or with H2 formed at the cathode surface. Since hydrodechlorination is the primary TCE reduction mechanism in this setup, reactions of the HS with the cathode limit transformation of TCE. The presence of limestone gravel reduced the impact of HS on TCE removal. The study concludes that presence of humic substances adversely affects TCE removal from contaminated groundwater by electrochemical reduction using palladized cathodes. PMID:26549889

  6. Fluorescence spectroscopy as a tool for quality assessment of humic substances

    Science.gov (United States)

    Boguta, Patrycja

    2016-04-01

    *The studies were partly carried out within the framework of a research project. The project was financed from funds of National Science Center on the base of decision number DEC-2013/11/D/NZ9/02545. Fluorescence spectroscopy belongs to modern, non-destructive, rapid and relatively cheap methods, as well as for many years it was successfully used in studies of organic compounds in the fields of medicine, biology and chemistry. On the other hand, soil organic matter is a group of compounds with a complex spatial structure showing a large number of groups with different kinds of fluorophores. This could suggest the possibility of application of fluorescence spectroscopy in assessing the quality of humic substances as well as in monitoring of their chemical transformations. The aim of study was chemical description of humic and fulvic acids based on fluorescence spectra, as well as an attempt of evaluation of changes occurring under the influence of different pH and during interactions with various concentrations of metal. The humic and fulvic acids were isolated from chemically different soils. The measurements were carried out on Hitachi fluorescence spectrometer in solutions with a concentration of humic acids 40mg dm-3, at pH from 3 to 7, and for the evaluation of the metal impact: with increasing Zn concentrations (0-50mg dm-3). The fluorescence spectra were recorded in the form of synchronous and emission-excitation matrices (EEM). Studies have shown the presence of different groups of fluorophores. Synchronous spectra were characterized by a well-separated bands showing fluorescence in the area of low, medium and high wavelengths, suggesting the presence of structures, both weakly and strongly humified. EEM spectra revealed map of fluorophores within wide ranges of emission and excitation. Fluorophores differed in both position and intensity. The highest intensity was observed for compounds with the lowest humification degree which might be due to high amount

  7. Humic substances in natural waters and their complexation with trace metals and radionuclides: a review. [129 references

    Energy Technology Data Exchange (ETDEWEB)

    Boggs, S. Jr.; Livermore, D.; Seitz, M.G.

    1985-07-01

    Dissolved humic substances (humic and fulvic acids) occur in surface waters and groundwaters in concentrations ranging from less than 1 mg(C)/L to more than 100 mg(C)/L. Humic substances are strong complexing agents for many trace metals in the environment and are also capable of forming stable soluble complexes or chelates with radionuclides. Concentrations of humic materials as low as 1 mg(C)/L can produce a detectable increase in the mobility of some actinide elements by forming soluble complexes that inhibit sorption of the radionuclides onto rock materials. The stability of trace metal- or radionuclide-organic complexes is commonly measured by an empirically determined conditional stability constant (K'), which is based on the ratio of complexed metal (radionuclide) in solution to the product concentration of uncomplexed metal and humic complexant. Larger values of stability constants indicate greater complex stability. The stability of radionuclide-organic complexes is affected both by concentration variables and envionmental factors. In general, complexing is favored by increased of radionuclide, increased pH, and decreased ionic strength. Actinide elements are generally most soluble in their higher oxidation states. Radionuclides can also form stable, insoluble complexes with humic materials that tend to reduce radionuclide mobility. These insoluble complexes may be radionuclide-humate colloids that subsequently precipitate from solution, or complexes of radionuclides and humic substances that sorb to clay minerals or other soil particulates strongly enough to immobilize the radionuclides. Colloid formation appears to be favored by increased radionuclide concentration and lowered pH; however, the conditions that favor formation of insoluble complexes that sorb to particulates are still poorly understood. 129 refs., 25 figs., 19 tabs.

  8. Differentiating ozone direct and indirect reactions on decomposition of humic substances.

    Science.gov (United States)

    Chiang, Yen-Pei; Liang, Yung-Ying; Chang, Cheng-Nan; Chao, Allen C

    2006-12-01

    The ozonation reaction is accomplished into two pathways: direct ozone oxidation and indirect free hydroxyl radical oxidation. Both reactions are proceeding simultaneously, thus, it is difficult to separate them and study their respective reaction mechanisms. Carbonate and bicarbonate react with free radicals that will effectively inhibit the indirect free radical oxidation without affecting the direct oxidation reaction. The feasibility of using these chemicals as scavengers to inhibit the hydroxyl radicals so that the direct ozone oxidation reaction and indirect free hydroxyl radical oxidation reaction can be differentiated is presented in this paper. The results will assist in achieving a better understanding of the ozone reaction mechanism in oxidizing organic substances. In this study, synthetic samples made of commercially available humic substance are used to carry out the inhibited and non-inhibited ozone oxidation experiments. The intersecting point of the ORP (oxidation reduction potential) time series curves of the inhibited and un-inhibited reactions, occurring at 120s after the onset of the oxidation reaction, marks the turning point at which all added scavenger chemicals have been completely exhausted. Based on the measured A(254) values, percentage distributions of direct ozone oxidation and indirect hydroxyl radical oxidation are estimated. The results indicate that the contribution of indirect reaction decreases with increasing amounts of inhibiting scavengers. The on-line ORP measurement results are simulated using a modified form of the Nernst equation expressed as ORP=11852-1196 pH+130 ln [(A(254,0)-A(254,t))(A(254,t))(-1)] with R(2) value of 0.99. In this equation, A(254) is the absorbance at 254 nm used to index the humic substance concentration while subscript 0 and t denote the initial and the final time, respectively.

  9. Organic Matter Stocks and the Interactions of Humic Substances with Metals in Araucaria Moist Forest Soil with Humic and Histic Horizons

    Directory of Open Access Journals (Sweden)

    Daniel Hanke

    Full Text Available ABSTRACT Soils with humic and histic horizons in tropical and subtropical ecosystems play an important role in determining the atmospheric C stock and its stabilization, climate regulation, water holding capacity, and environmental filtering, due to the different functions of soil organic matter (SOM. However, the processes and mechanisms that regulate SOM dynamics in these soils are not clear. The objectives of this study were: i determine the C and N stocks and ii investigate the SOM chemical fractions and their interactions with Fe and Al ions in soils with humic and histic horizons of a toposequence under Araucaria moist forest in southern Brazil. The soils sampled were classified as Humic Hapludox (top - not hydromorphic, Fluvaquentic Humaquepts (lower third - hydromorphic, and Typic Haplosaprists (floodplain - hydromorphic. The C and N contents were determined in bulk soil samples and SOM chemical fractions; in these fractions, Fe and Al co-extracted contents were also determined. The chemical composition of humin and humic acid fractions was investigated by FTIR spectroscopy. The C content in the toposequence increased from the top to the lowest position. The differences observed in SOM content and SOM chemical composition were defined by the differences in soil water regime. The amount of C stored in the subsurface horizons is about 70 % of total organic C. The carbohydrate-like structures in the humin fraction were protected from solubilization through interaction with iron oxides, which may represent an important mechanism for labile organic compound preservation in these soils. The soluble humic substances showed the highest Fe and Al contents, and their compartments have different affinities for Fe and Al.

  10. Fluorescence detection to determine proteins and humic-like substances fingerprints of exopolymeric substances (EPS) from biological sludges performed by size exclusion chromatography (SEC).

    Science.gov (United States)

    Bhatia, Divya; Bourven, Isabelle; Simon, Stéphane; Bordas, François; van Hullebusch, Eric D; Rossano, Stéphanie; Lens, Piet N L; Guibaud, Gilles

    2013-03-01

    Fingerprints of extracellular polymeric substances (EPS) from activated and anaerobic granular sludges were obtained by size exclusion chromatography coupled to UV (210 and 280 nm) and fluorescence (221/350 nm (protein-like molecules) and 345/443 nm (humic-like substances)) detection. The total area below the peaks obtained with fluorescence detection is linked to the protein or humic-like substances EPS content. The EPS protein fingerprints, usually recorded with UV-280 nm, change dramatically, mainly in the relative size of peaks when they were measured by a florescence detection method. It means that the apparent molecular weight (aMW) distribution of EPS chomatophores and fluorophores is different. Protein-like and humic-like substances were found to be specific fingerprints of the EPS, affected by the type and origin of the bacterial aggregate and improve EPS sample differentiation. The protein-like fraction of EPS displays a wide range of aMW (>600 kDa-<10 kDa) whereas the humic-like substances fraction is composed of molecules of low aMW (6-<1.2 kDa). Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Influence of fly-ash produced by lignite power station on humic substances in ectohumus horizons of Podzols

    Science.gov (United States)

    Weber, Jerzy; Jerzykiewicz, Maria; Jamroz, Elżbieta; Kocowicz, Andrzej; Dębicka, Magdalena; Ćwieląg-Piasecka, Irmina

    2017-04-01

    Literature on fly-ash influence on the environment report mainly on alkalization effect on vegetation and changes in chemistry of forest floor. As far as now soils were examined only for changes in pH in surface horizons, physical properties and heavy metal solubility. Soil properties strongly depend on soil organic matter content and humic substances properties, thus their modification plays a crucial role in soil forming processes and changes in the environment. From the other side, the alkalization effects on podzolization processes and particularly on humic substances have not been recognized. The aim of this paper was to characterize changes in properties of humic substances in ectohumus horizons of Podzols affected by alkali blown out from fly-ash dumping site of power station Bełchatów, central Poland. The objects of the investigation were Podzols derived from loose quartz sand, developed under pine forest. They surround the dumping site, which was established to store wastes from lignite combustion in Bełchatów power station. The samples were collected from ectohumus horizons in direct vicinity of the dumping site (50 m) as well as in the control area (7.3 km away) in five replications. Determination of elemental composition and spectroscopic analysis (EPR, FT-IR, ICP-OES and UV-Vis) were performed for humic acids, fulvic acids and humines extracted with standard IHSS procedure. An increase of pH in ectohumus horizons caused by the influence of fly-ash leads to change in humic substances structure. Obtained results showed that humic and fulvic acids from fly-ash affected Podzols indicated higher contents of nitrogen and sulphur, as well as higher O/C and lower C/N ratios. This points out a higher degree of their humification. Also EPR analyses of humic acids and humins affected by fly-ash indicated higher metal ions concentrations. However, the increase of Mn and Fe ions concentration did not affect the Fe(III) and Mn(II) band intensities of EPR spectra

  12. PREDICTING CHEMICAL REACTIVITY OF HUMIC SUBSTANCES FOR MINERALS AND XENOBIOTICS: USE OF COMPUTATIONAL CHEMISTRY, SCANNING PROBE MICROSCOPY AND VIRTUAL REALITY

    Science.gov (United States)

    In this chapter we review the literature on scanning probe microscopy (SPM), virtual reality (VR), and computational chemistry and our earlier work dealing with modeling lignin, lignin-carbohydrate complexes (LCC), humic substances (HSs) and non-bonded organo-mineral interactions...

  13. Comparable investigation of the molecular size distribution and the amount of humic substances isolated from ONKALO, Olkiluoto, 2011

    Energy Technology Data Exchange (ETDEWEB)

    Luste, S.; Maekelae, J.; Manninen, P. [Ramboll Finland Oy, Espoo (Finland)

    2012-06-15

    The humic substances (HS) at groundwater from ONKALO, Olkiluoto were studied in order to determine the apparent molecular size distribution and the amount of humic substances. Humic substances were isolated from the water sample using DAX-8 resin and eluted with 0.1 M NaOH. The molecular size distribution was defined using high performance size exclusion chromatography (HPSEC) and ultraviolet (UV) and refractive index (RI) detector. In the SEC calibration (polystyrene sulfonate) sodium salts (PSS) were employed. Different eluents (NaNO{sub 3}, Na-acetate and asetonitrile) with phosphate buffer and distinct ionic strengths were studied in order to optimize the determination method. The amount of humic substances was determined using total organic carbon (TOC) measurements. The results were compared with the previous ones in order to find out the variation of different methods (HPSEC) and to follow up the HS quantity (TOC). The method developed during the study is considered to be suitable for the HS molecular size distribution follow up, although the method development is suggested to be continued. (orig.)

  14. A humic substance analogue AQDS stimulates Geobacter sp. abundance and enhances pentachlorophenol transformation in a paddy soil.

    Science.gov (United States)

    Chen, Manjia; Tong, Hui; Liu, Chengshuai; Chen, Dandan; Li, Fangbai; Qiao, Jiangtao

    2016-10-01

    Soil humic substances can be used as redox mediators in accelerating the biotransformation of organic pollutants, and humus-respiring bacteria are widely distributed in soils. However, the impact of humic substances on the soil microbial community during the biotransformation of organic pollutants is expected to be crucial while remains to be unclear. In this study, the biostimulation of indigenous microbial communities and the consequent effects on anaerobic transformation of pentachlorophenol (PCP) by a model humic substance, anthraquinone-2,6-disulfonate (AQDS), were systematically investigated in a paddy soil. The addition of AQDS was observed to increase the production of HCl-extractable Fe(II) and enhance the PCP transformation rates consequently. The pseudo-first-order rate constants of the PCP transformation showed a positive exponential relationship with the AQDS dosage. The terminal restriction fragment length polymorphism (T-RFLP) results indicated the substantial effect of added AQDS on soil microbial community. The enhanced abundance of Geobacter sp. was disclosed to be most critical for accelerated PCP transformation when with AQDS, in which Geobacter sp. functioned for promoting the generation of active Fe(II) and consequently enhancing the PCP transformation rates. The transformation rates of PCP were exponentially correlated with the abundance of Geobacter sp. positively. The findings are expected to improve the understanding of diversity and ubiquity of microorganisms in humic substances-rich soils for accelerating the transformations of soil chlorinated pollutants. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Mitigation of Fe(0) nanoparticles toxicity to Trichosporon cutaneum by humic substances.

    Science.gov (United States)

    Pádrová, Karolína; Maťátková, Olga; Šiková, Michaela; Füzik, Tibor; Masák, Jan; Čejková, Alena; Jirků, Vladimír

    2016-01-25

    Zero-valent iron nanoparticles (nZVI) are a relatively new option for the treatment of contaminated soil and groundwater. However, because of their apparent toxicity, nZVI in high concentrations are known to interfere with many autochthonous microorganisms and, thus, impact their participation in the remediation process. The effect of two commercially available nZVI products, Nanofer 25 (non-stabilized) and Nanofer 25S (stabilized), was examined. Considerable toxicity to the soil yeast Trichosporon cutaneum was observed. Two chemically different humic substances (HSs) were studied as a possible protection agent that mitigates nZVI toxicity: oxidized oxyhumolite X6 and humic acid X3A. The effect of addition of HSs was studied in different phases of the experiment to establish the effect on cells and nZVI. SEM and TEM images revealed an ability of both types of nZVI and HSs to adsorb on surface of the cells. Changes in cell surface properties were also observed by zeta potential measurements. Our results indicate that HSs can act as an electrosteric barrier, which hinders mutual interaction between nZVI and treated cell. Thus, the application of HS seems to be a promising solution to mitigating the toxic action of nZVI. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Identifying the key factors that affect the formation of humic substance during different materials composting.

    Science.gov (United States)

    Wu, Junqiu; Zhao, Yue; Qi, Haishi; Zhao, Xinyu; Yang, Tianxue; Du, Yingqiu; Zhang, Hui; Wei, Zimin

    2017-11-01

    The aim of this work was to identify the factors which can affect humic substance (HS) formation. Composting periods, HS precursors, bacteria communities and environment factors were recognized as the key factors and few studies explored the potential relationships among them. During composting, HS precursors were mainly formed in the heating and thermophilic phases, but HS were polymerized in the cooling and mature phases. Moreover, bacterial species showed similar classification of community structure in the same composting period of different materials. Furthermore, structural equation model showed that NH4(-)-N and NO3(-)-N were the indirect environmental factors for regulating HS formation by the bacteria and precursors as the indirect and direct driver, respectively. Therefore, both environmental factors and HS precursors can be the regulating factors to promote HS formation. Given that, a new staging regulating method had been proposed to improve the amount of HS during different materials composting. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. The possible use of soluble humic substances for remediation of heavy metal polluted soils

    DEFF Research Database (Denmark)

    Borggaard, Ole K.; Jensen, Julie Katrine; Holm, Peter Engelund

    2008-01-01

    . Therefore, the potential of soluble natural humic substances (HS) to extract heavy metals from contaminated soils is tested as an environmental friendly substitute for EDTA. A strongly polluted urban soil and a moderately polluted agricultural soil were extracted at neutral pH in batch mode by three HS......Polluted soil is a common and serious environmental problem. While reliable methods exist for cleaning soil contaminated by organic compounds through degradation, remediation of heavy metal polluted soils awaits an appropriate solution. This is because heavy metals are nondegradable and generally...... extraction. Heavy metal extraction with dissolved HS is compared with EDTA at the same concentration and sequential extraction has been performed to identify extracted pools. The results indicate a clear potential of using HS solutions for remediation of heavy metal polluted soils, which is fortunate...

  18. Alkaline extraction of humic substances from peat applied to organic-mineral fertilizer production

    Directory of Open Access Journals (Sweden)

    B. Saito

    2014-09-01

    Full Text Available An organic-mineral fertilizer based on humic substances (HSs and potassium was developed based on the alkaline extraction of HSs from peat. The HSs have interesting properties for use as a fertilizer since they improve the physical and chemical structure of the soil and provide a source of organic carbon which is readily absorbable by the plants, whereas potassium is a primary nutrient for plants. It was found that highly decomposed peats containing a small inorganic fraction are more favorable for the extraction of HSs. Using these peats, organic-mineral fertilizers that meet the Brazilian legislation have been obtained for a peat-extractant mixture containing 2.57 wt% total organic content (TOC, a K2O/TOC ratio of 1 wt% and an extraction time of 12 hours.

  19. Structure and dynamics of humic substances and model poly-electrolytes in solution; Structure et dynamique de substances humiques et polyelectrolytes modeles en solution

    Energy Technology Data Exchange (ETDEWEB)

    Roger, G.

    2010-09-15

    In the frame of a study about the feasibility of an underground storage of radioactive wastes, we focused on the role of degraded natural organic matter in the eventual transport of radionuclides in the environment. We are more interested by the determination of electro kinetic properties of these humic substances rather than the description of speciation reaction already widely discussed in the literature. We chose to determine the size and the charge of these humic substances thanks to an original method: high precision conductometry. This technique, associated to a suited transport theory, allows to describe the mobility of charged species in solution when taking into account the pairs interactions. We have participated in the development of this transport theory and we use it in order to determine the size and the charge of humic substances and a reference polyelectrolyte in different conditions of pH and ionic strength. All these experimental results obtained by conductometry were correlated with other experimental and theoretical methods: Atomic Force Microscopy, dynamic light scattering, laser zeta-metry and Monte-Carlo simulations. The obtained results confirm the generally admitted idea that humic substances are nano-metric entities having complexing properties towards cations and that can aggregate to form supra molecular structures. The effect of the ions present in the environment (sodium, calcium, magnesium) has been investigated. Finally the complexation of europium (which is considered as a good analogue of americium 241) has also been analysed by square wave voltammetry. (author)

  20. Biogeochemical interactions among the arsenic, iron, humic substances, and microbes in mud volcanoes in southern Taiwan.

    Science.gov (United States)

    Liu, Chia-Chuan; Maity, Jyoti Prakash; Jean, Jiin-Shuh; Sracek, Ondra; Kar, Sandeep; Li, Zhaohui; Bundschuh, Jochen; Chen, Chien-Yen; Lu, Hsueh-Yu

    2011-01-01

    Fluid and mud samples collected from Hsiaokunshui (HKS), Wushanting (WST), Yenshuikeng (YSK), Kunshuiping (KSP), Liyushan (LYS), and Sinyangnyuhu (SYNH) mud volcanoes of southwestern Taiwan were characterized for major ions, humic substances (HS) and trace elements concentrations. The relationship between the release of arsenic (As) and activities of sulfate-reducing bacteria has been assessed to understand relevant geochemical processes in the mud volcanoes. Arsenic (0.02-0.06 mg/L) and humic substances (4.13 × 10(-4) to 1.64 × 10(-3) mM) in the fluids of mud volcanoes showed a positive correlation (r = 0.99, p mud volcano. Arsenic and iron in mud sediments formed two separate groups i) high As, but low Fe in HKS, WST, and SYNH; and ii) low As, but high Fe in the YSK, KSP, and LYS mud volcanoes. The Eh(S.H.E.) values of the mud volcano liquids were characterized by mild to strongly reducing conditions. The HKS, SYNH, and WST mud volcanoes (near the Chishan Fault) belongs to strong reducing environment (-33 to -116 mV), whereas the LYS, YSK, and KSP mud volcanoes located near the coastal plain are under mild reducing environment (-11 to 172 mV). At low Eh values mud volcanoes, saturation index (SI) values of poorly crystalline phases such as amorphous ferric hydroxide indicate understaturation, whereas saturation is reached in relatively high Eh(S.H.E.) values mud volcanoes. Arsenic contents in sediments are low, presumably due to its release to fluids (As/Fe ratio in YSK, KSP, and LYS sediment: 4.86 × 10(-4)-6.20 × 10(-4)). At low Eh(S.H.E.) values (mild to strong reducing environment), arsenic may co-precipitate with sulfides as a consequence of sulfate reduction (As/Fe ratios in WST, HKS, and SYNH sediments: 0.42-0.69).

  1. A meta-analysis of plant-growth response to humic substance applications

    Science.gov (United States)

    Patti, Antonio; Rose, Michael; Little, Karen; Jackson, Roy; Cavagnaro, Tim

    2013-04-01

    Humic substances (HS) are a category of naturally occurring organic compounds that arise from the decomposition and transformation of plant, animal and microbial residues (Maccarthy 2001). The loss of humic material, together with overall reductions in soil organic matter, is of concern because they play important roles in maintaining key soil functions and plant productivity (Lal 2004). Consequently, there is interest in the application of HS-based amendments, often derived from agricultural wastes (e.g composts) to remediate and/or maintain soil health (Quilty and Cattle 2011). In light of the potential benefits of HS, together with their inconsistent performance under field conditions, we sought to quantitatively review the effects of HS on plant growth, by undertaking a meta-analysis of the literature. A total of 390 papers were originally selected from the current literature. A number of criteria were applied to reduce this number to 81, from which the meta-analysis was undertaken. The 81 papers comprised 57 studies presenting data on shoot (or total) dry weight and 39 studies reporting root dry weight. As part of the meta-analysis we attempted: (i) to quantify the magnitude and likelihood of plant growth promotion, in terms of shoot and root biomass, resulting from HS application, (ii) to determine the influence of environmental conditions, plant type, humic substance properties, and the manner of application on plant growth response to HS, (iii) to identify gaps in our understanding of the interaction of HS with plants, and (iv) to provide some general recommendations for the practical use of HS in agronomic systems and suggestions for future work. Some of the key findings from this meta-analysis included: Many papers lack details on HS chemical characteristics The application of HS needs to be tailored to the environmental conditions in which they will be used. The effect of HS on shoot biomass was not only dependent on the source and rate of application

  2. Humic substances from sewage sludge compost as washing agent effectively remove Cu and Cd from soil.

    Science.gov (United States)

    Kulikowska, Dorota; Gusiatin, Zygmunt Mariusz; Bułkowska, Katarzyna; Kierklo, Katarzyna

    2015-10-01

    Although commercially available biosurfactants are environmentally friendly and effectively remove heavy metals from soil, they are costly. Therefore, this study investigated whether inexpensive humic substances (HS) from sewage sludge compost could effectively remove copper (Cu) and cadmium (Cd) from highly contaminated sandy clay loam (S1) and clay (S2). The optimum HS concentration and pH were determined, as well process kinetics. Under optimum conditions, a single washing removed 80.7% of Cu and 69.1% of Cd from S1, and 53.2% and 36.5%, respectively, from S2. Triple washing increased removal from S1 to almost 100% for both metals, and to 83.2% of Cu and 88.9% of Cd from S2. Triple washing lowered the potential ecological risk (Er(i)) of the soils, especially the risk from Cd. HS substances show potential for treating soils highly contaminated with heavy metals, and HS from other sources should be tested with these and other contaminants. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Feasibility of humic substances removal by enhanced coagulation process in surface water

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Amin

    2012-01-01

    Full Text Available Aims: This study evaluates the effectiveness of polyaluminium chloride (PAClas a coagulant for enhanced coagulation (EC of humic substances (HS in surface water. Materials and Methods: Dissolved organic carbon (DOC, ultraviolet absorbance (UV 254 , specific ultraviolet absorbance (SUVA, and humic acid (HA were determined as the HS indices. HS was extracted by Amberlit XAD-7HP from water and HA was analyzed by high performance liquid chromatography (HPLC. The HS index was determined in raw water and after clarification and filtration in all seasons. The efficiency of PACl for removal of HS, both in the jar test and pilot scale were determined. Results: The average extraction efficiency for XAD-7HP was 77%, and the HA concentration was determined in all seasons ranging from 0.15 to 0.29 mg/ L in raw water. The DOC in raw water was in the range of 1.5 to 4mg/L, in all seasons. The average removal efficiency of PACl for EC was 52% for HA in the pilot scale. Also the average removal efficiencies of PACl EC for DOC and UV 254 were 43 and 57% on the pilot scale and 38 and 41% in the jar test, respectively. The optimum pH for removal of HS was 7.5 ± 0.2 and the optimum PACl dose was 12 ± 0.5 mg/L. Conclusions: After EC, the aluminum concentration was lower than the maximum concentration level (MCL of aluminum in drinking water ( 8.5 was very poor for the HS index and turbidity.

  4. Comprehensive characterization of oil refinery effluent-derived humic substances using various spectroscopic approaches.

    Science.gov (United States)

    Lingbo, Li; Song, Yan; Congbi, Han; Guangbo, Shan

    2005-07-01

    Refinery effluent-derived humic substances (HS) are important for developing refinery effluent reclamation techniques and studying the environmental chemistry of wastewater effluents. In this study, dissolved organic matter (DOM) from refinery effluent was concentrated using a portable reverse osmosis (RO) system. HS were isolated from RO retentates with XAD-8 resin. A variety of approaches such as specific UV absorbance at 254nm (SUV(254)), elemental analysis, size exclusion chromatography (SEC), solid-state cross polarization magic angle spinning (13)C nuclear magnetic resonance spectrometry ((13)C CPMAS NMR), Fourier transform infrared spectrometry (FTIR), and electrospray ionization/ion trap/mass spectrometry (ESI/ion trap/MS) were employed for characterization of HS. The portable RO system exhibited high yield and recovery of DOM for concentrating refinery effluent. The concentration of dissolved organic carbon (DOC) in the refinery effluent was 9.9mg/l, in which humic acids (HA) and fulvic acids (FA) accounted for 2.3% and 34.6%, respectively. Elemental and SUV(254) analyses indicated relative high amounts of aliphatic structures and low amounts of aromatic structures in refinery effluent-derived HS. Refinery effluent-derived HS displayed lower molecular weight than natural HS. The number-average molecular weight (M(n)) and the weight-average molecular weight (M(w)) of HA were 1069 and 2934, and those of FA were 679 and 1212 by SEC, respectively. By ESI/ion trap/MS, the M(n) and the M(w) of FA were 330 and 383. Four kinds of carbon structures (aliphatic, aromatic, heteroaliphatic, and carboxylic carbons) were found in refinery effluent-derived HS by (13)C NMR analysis. The quantitative results support the interpretation that these HS are rich in aliphatic carbons and poor in aromatic carbons. Proteinaceous materials were identified by FTIR analysis in refinery effluent-derived HS.

  5. Humic substances increase survival of freshwater shrimp Caridina sp. D to acid mine drainage.

    Science.gov (United States)

    Holland, Aleicia; Duivenvoorden, Leo J; Kinnear, Susan H W

    2013-02-01

    Humic substances (HS) are known to decrease the toxicity of heavy metals to aquatic organisms, and it has been suggested that they can provide buffering protection in low pH conditions. Despite this, little is known about the ability for HS to increase survival to acid mine drainage (AMD). In this study, the ability of HS to increase survival of the freshwater shrimp (Caridina sp. D sensu Page et al. in Biol Lett 1:139-142, 2005) to acid mine drainage was investigated using test waters collected from the Mount Morgan open pit in Central Queensland with the addition of Aldrich humic acid (AHA). The AMD water from the Mount Morgan open pit is highly acidic (pH 2.67) as well as contaminated with heavy metals (1780 mg/L aluminum, 101 mg/L copper [Cu], 173 mg/L manganese, 51.8 mg/L zinc [Zn], and 51.8 mg/L iron). Freshwater shrimp were exposed to dilutions in the range of 0.5 % to 5 % AMD water with and without the addition of 10 or 20 mg/L AHA. In the absence of HS, all shrimp died in the 2.5 % AMD treatment. In contrast, addition of HS increased survival in the 2.5 % AMD treatment by ≤66 % as well as significantly decreased the concentration of dissolved Cu, cobalt, cadmium, and Zn. The decreased toxicity of AMD in the presence of HS is likely to be due to complexation and precipitation of heavy metals with the HS; it is also possible that HS caused changes to the physiological condition of the shrimp, thus increasing their survival. These results are valuable in contributing to an improved understanding of potential role of HS in ameliorating the toxicity of AMD environments.

  6. Temporal changes in soil bacterial diversity and humic substances degradation in subarctic tundra soil.

    Science.gov (United States)

    Park, Ha Ju; Chae, Namyi; Sul, Woo Jun; Lee, Bang Yong; Lee, Yoo Kyung; Kim, Dockyu

    2015-04-01

    Humic substances (HS), primarily humic acids (HA) and fulvic acids (FA), are the largest constituent of soil organic matter. In microcosm systems with subarctic HS-rich tundra soil (site AK 1-75; approximately 5.6 °C during the thawing period) from Council, Alaska, the HA content significantly decreased to 48% after a 99-day incubation at 5 °C as part of a biologically mediated process. Accordingly, levels of FA, a putative byproduct of HA degradation, consistently increased to 172% during an identical incubation process. Culture-independent microbial community analysis showed that during the microcosm experiments, the relative abundance of phyla Proteobacteria (bacteria) and Euryarchaeota (archaea) largely increased, indicating their involvement in HS degradation. When the indigenous bacteria in AK 1-75 were enriched in an artificial mineral medium spiked with HA, the changes in relative abundance were most conspicuous in Proteobacteria (from 60.2 to 79.0%), specifically Betaproteobacteria-related bacteria. One hundred twenty-two HA-degrading bacterial strains, primarily from the genera Paenibacillus (phylum Firmicutes) and Pseudomonas (class Gammaproteobacteria), were cultivated from AK 1-75 and nearby sites. Through culture-dependent analysis with these bacterial isolates, we observed increasing HS-degradation rates in parallel with rising temperatures in a range of 0 °C to 20 °C, with the most notable increase occurring at 8 °C compared to 6 °C. Our results indicate that, although microbial-mediated HS degradation occurs at temperature as low as 5 °C in tundra ecosystems, increasing soil temperature caused by global climate change could enhance HS degradation rates. Extending the thawing period could also increase degradation activity, thereby directly affecting nearby microbial communities and rhizosphere environments.

  7. The influence of organic matter on sorption and fate of glyphosate in soil - Comparing different soils and humic substances

    Energy Technology Data Exchange (ETDEWEB)

    Albers, Christian N., E-mail: calbers@ruc.d [Dept. of Geochemistry, Geological Survey of Denmark and Greenland, DK-1350 Copenhagen (Denmark); Dept. of Science, Systems and Models, Roskilde University, DK-4000 Roskilde (Denmark); Banta, Gary T. [Dept. of Environmental, Social and Spatial Change, Roskilde University, DK-4000 Roskilde (Denmark); Hansen, Poul Erik [Dept. of Science, Systems and Models, Roskilde University, DK-4000 Roskilde (Denmark); Jacobsen, Ole S. [Dept. of Geochemistry, Geological Survey of Denmark and Greenland, DK-1350 Copenhagen (Denmark)

    2009-10-15

    Soil organic matter (SOM) is generally believed not to influence the sorption of glyphosate in soil. To get a closer look on the dynamics between glyphosate and SOM, we used three approaches: I. Sorption studies with seven purified soil humic fractions showed that these could sorb glyphosate and that the aromatic content, possibly phenolic groups, seems to aid the sorption. II. Sorption studies with six whole soils and with SOM removed showed that several soil parameters including SOM are responsible for the strong sorption of glyphosate in soils. III. After an 80 day fate experiment, approx40% of the added glyphosate was associated with the humic and fulvic acid fractions in the sandy soils, while this was the case for only approx10% of the added glyphosate in the clayey soils. Glyphosate sorbed to humic substances in the natural soils seemed to be easier desorbed than glyphosate sorbed to amorphous Fe/Al-oxides. - Glyphosate was sorbed by purified humic substances and a significant amount of glyphosate was found to be associated with soil organic matter in whole soils.

  8. Improving Lowland Rice (O. sativaL. cv. MR219) Plant Growth Variables, Nutrients Uptake, and Nutrients Recovery Using Crude Humic Substances

    National Research Council Canada - National Science Library

    Palanivell, Perumal; Ahmed, Osumanu Haruna; Ab Majid, Nik Muhamad; Jalloh, Mohamadu Boyie; Susilawati, Kasim

    2015-01-01

    .... 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...

  9. Synthesis of carboxylated styrene polymer for internal calibration of Fourier transform ion cyclotron resonance mass-spectrometry of humic substances.

    Science.gov (United States)

    Zherebker, Alexander; Turkova, Alexandra V; Kostyukevich, Yury; Kononikhin, Alexey; Zaitsev, Kirill V; Popov, Igor A; Nikolaev, Eugene; Perminova, Irina V

    2017-08-01

    We report synthesis and application of the novel carboxylated styrene for internal calibration of Fourier transform ion cyclotron resonance mass-spectra of humic substances. The calibrant was synthesized in five steps from acetylsalicylic acid (aspirin) followed by spontaneous polymerization of vinyl salicylic acid. Aromatic nature of the prepared polymer enabled its simultaneous analysis in the presence of the Suwannee River fulvic acid without using dual-spray approach. The major advantage of the calibrant proposed in this study is a lack of suppression of humic substances signals and maintenance of peak intensity distribution. The appropriate calibration resulted in an increased number of unambiguous identification in Suwannee River fulvic acid. Thanks to the higher mass accuracy, it was also possible to refine attribution of the CHOS species to hydrolysable tannins as opposed to the erroneous previous assignment to the condensed tannins.

  10. Addition of a Worm Leachate as Source of Humic Substances in the Drinking Water of Broiler Chickens

    OpenAIRE

    Gomez-Rosales, S.; M. de L. Angeles

    2015-01-01

    The objective of this research was to evaluate the growth performance, the apparent ileal digestibility of nitrogen and energy, the retention of nutrients and the apparent metabolizable energy corrected to zero nitrogen retention (AMEn) in broiler chickens supplemented with increasing doses of a worm leachate (WL) as a source of humic substances (HS) in the drinking water. In Exp. 1, 140 male broilers were penned individually and assigned to four WL levels (0%, 10%, 20%, and 30%) mixed in the...

  11. Monitoring changes in the structure and properties of humic substances following ozonation using UV-Vis, FTIR and (1)H NMR techniques.

    Science.gov (United States)

    Rodríguez, Francisco J; Schlenger, Patrick; García-Valverde, María

    2016-01-15

    The main objective of this work is to conduct a comprehensive structural characterization of humic substances using the following experimental techniques: FTIR, 1H NMR and several UV–Vis parameters (Specific UV Absorbance at 254 nm or SUVA254, SUVA280, A400, the absorbance ratios A210/254, A250/365, A254/203, A254/436, A265/465, A270/400, A280/350, A465/665, the Absorbance Slope Index (ASI), the spectral slopes S275–295, S350–400 and the slope ratio SR). These UV–Vis parameters have also been correlated with key properties of humic substances such as aromaticity, molecular weight (MW) and trihalomethane formation potential (THMFP). An additional objective of this work is also to evaluate the usefulness of these techniques to monitor structural changes in humic substances produced by the ozonation treatment. Four humic substances were studied in this work: three of them were provided by the International Humic Substances Society (Suwannee River Fulvic Acid Standard: SRFA, Suwannee River Humic Acid Standard: SRHA and Nordic Reservoir Fulvic Acid Reference: NLFA) and the other one was a terrestrial humic acid widely used as a surrogate for aquatic humic substances in various studies (Aldrich Humic Acid: AHA). The UV–Vis parameters showing the best correlations with aromaticity in this study were SUVA254, SUVA280, A280/A350 ratio and A250/A364 ratio. The best correlations with molecular weight were for SUVA254, SUVA280 and A280/A350 ratio. Finally, in the case of the THMFP it was STHMFP-per mol HS the parameter showing good correlations with most of the UV–Vis parameters studied (especially with A280/A350 ratio, A265/A465 ratio and A270/A400 ratio) whereas STHMFP-per mg C showed poor correlations in most cases. On the whole, the UV–Vis parameter showing the best results was A280/A350 ratio as it showed excellent correlations for the three properties studied (aromaticity, MW and THMFP). A decrease in aromaticity following ozonation of humic substances can

  12. Photocatalytic degradation of humic substances in aqueous solution using Cu-doped ZnO nanoparticles under natural sunlight irradiation.

    Science.gov (United States)

    Maleki, Afshin; Safari, Mahdi; Shahmoradi, Behzad; Zandsalimi, Yahya; Daraei, Hiua; Gharibi, Fardin

    2015-11-01

    In this study, Cu-doped ZnO nanoparticles were investigated as an efficient synthesized catalyst for photodegradation of humic substances in aqueous solution under natural sunlight irradiation. Cu-doped ZnO nanocatalyst was prepared through mild hydrothermal method and was characterized using FT-IR, powder XRD and SEM techniques. The effect of operating parameters such as doping ratio, initial pH, catalyst dosage, initial concentrations of humic substances and sunlight illuminance were studied on humic substances degradation efficiency. The results of characterization analyses of samples confirmed the proper synthesis of Cu-doped ZnO nanocatalyst. The experimental results indicated the highest degradation efficiency of HS (99.2%) observed using 1.5% Cu-doped ZnO nanoparticles at reaction time of 120 min. Photocatalytic degradation efficiency of HS in a neutral and acidic pH was much higher than that at alkaline pH. Photocatalytic degradation of HS was enhanced with increasing the catalyst dosage and sunlight illuminance, while increasing the initial HS concentration led to decrease in the degradation efficiency of HS. Conclusively, Cu-doped ZnO nanoparticles can be used as a promising and efficient catalyst for degradation of HS under natural sunlight irradiation.

  13. Influence of seasonality on the interaction of mercury with aquatic humic substances extracted from the Middle Negro River Basin (Amazon)

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Luciana C. de, E-mail: lcamargo@ufscar.br [Federal University of Sao Carlos (UFSCar), Sorocaba, SP (Brazil); Botero, Wander G. [Federal University of Alagoas (UFAL), Arapiraca, AL (Brazil); Santos, Felipe A. [Institute of Biosciences, Sao Paulo State University (UNESP), Botucatu, SP (Brazil); Sargentini Junior, Ezio [National Amazon Research Institute (INPA), Manaus, AM (Brazil); Rocha, Julio C.; Santos, Ademir dos [Institute of Chemistry of Araraquara, Sao Paulo State University (UNESP), Araraquara, SP (Brazil)

    2012-09-15

    High mercury concentrations in different environmental matrices in the Amazon have been attributed to mining activities. However, high concentrations of mercury are also present in the soil and water in places like in the middle of the Negro River Basin, which is far away from any anthropogenic emission sources. The Amazon region is characterized by two different regional seasons, with well-defined flood and low water periods. The objective of this work was to investigate the seasonal influences of the interaction between mercury and aquatic humic substances (AHS), which are the main agents of the natural organic complexation capacity. The results of the multivariate statistical analysis of the data showed that the humic substances had different structural characteristics, depending on each season. The ability of humic substances to form complexes with Hg(II) is not directly related to their carbon content, but to the nature and availability of the functional groups present in its structure. The functional groups are carboxylic and aromatic directly related to the higher complexation capacity of AHS by mercury ions. (author)

  14. Total carbon content and humic substances quality in selected subtypes of Cambisols

    Directory of Open Access Journals (Sweden)

    Veronika Petrášová

    2009-01-01

    Full Text Available Cambisols cover an estimated 45% of agricultural soils in the Czech Republic. We aimed our work at stabile forms of organic carbon and humic substances quality in Cambisols under different types of soil management (grassland and arable soil. Object of our study were the following subtypes of Cambisols: Eutric Cambisol (locality Vatín – arable soil, Eutric Cambisol (locality Vatín – grassland, Haplic Cambisol (locality Náměšť n/Oslavou – arable soil, Leptic Cambisol (locality Ocmanice – grassland, Haplic Cambisol (locality Nové Město na Moravě – arable soil, Haplic Cambisol (locality Přemyslov – Tři Kameny – grassland, Arenic Cambisol (locality Pocoucov – arable soil, Dystric Cambisol (locality Sněžné – arable soil, Dystric Cambisol (locality Velká Skrovnice – arable soil, Dystric Cambisol (locality Vojnův Městec – arable soil. Non-destructive spectroscopic methods such as UV-VIS spectroscopy, synchronous fluorescence spectroscopy (SFS and 13C NMR spectroscopy for humic substances (HS quality assessment were used. Total organic carbon (TOC content was determined by oxidimetric titration. Fractionation of HS was made by short fractionation method. Isolation of pure humic ­acids (HA preparation was made according to the standard IHSS method.Results showed that TOC and humus content varied from 2.70 % (grassland to 1.3 % (arable soil. Ave­ra­ge HS sum was 8.4 mg / kg in grassland and 6.4 mg / kg in arable soil. Average HA sum was 3.6 mg / kg in grassland and 3 mg / kg in arable soil. Fulvic acids (FA content was 4.7 mg / kg in grassland and 3.7 mg / kg in arable soil. HS quality was low and very similar for all studied samples. HA/FA ratio low (< 1. HS absorbance in UV-VIS spectral range was low and similar in all studied samples. Higher absorption in this spectral range was closely connected with higher HS content. Also in 2D-synchronous fluorescence scan spectra

  15. Effects of humic substances on precipitation and aggregation of zinc sulfide nanoparticles

    Science.gov (United States)

    Deonarine, Amrika; Lau, Boris L.T.; Aiken, George R.; Ryan, Joseph N.; Hsu-Kim, Heileen

    2011-01-01

    Nanoparticulate metal sulfides such as ZnS can influence the transport and bioavailability of pollutant metals in anaerobic environments. The aim of this work was to investigate how the composition of dissolved natural organic matter (NOM) influences the stability of zinc sulfide nanoparticles as they nucleate and aggregate in water with dissolved NOM. We compared NOM fractions that were isolated from several surface waters and represented a range of characteristics including molecular weight, type of carbon, and ligand density. Dynamic light scattering was employed to monitor the growth and aggregation of Zn−S−NOM nanoparticles in supersaturated solutions containing dissolved aquatic humic substances. The NOM was observed to reduce particle growth rates, depending on solution variables such as type and concentration of NOM, monovalent electrolyte concentration, and pH. The rates of growth increased with increasing ionic strength, indicating that observed growth rates primarily represented aggregation of charged Zn−S−NOM particles. Furthermore, the observed rates decreased with increasing molecular weight and aromatic content of the NOM fractions, while carboxylate and reduced sulfur content had little effect. Differences between NOM were likely due to properties that increased electrosteric hindrances for aggregation. Overall, results of this study suggest that the composition and source of NOM are key factors that contribute to the stabilization and persistence of zinc sulfide nanoparticles in the aquatic environment.

  16. Predicting apparent singlet oxygen quantum yields of dissolved black carbon and humic substances using spectroscopic indices.

    Science.gov (United States)

    Du, Ziyan; He, Yingsheng; Fan, Jianing; Fu, Heyun; Zheng, Shourong; Xu, Zhaoyi; Qu, Xiaolei; Kong, Ao; Zhu, Dongqiang

    2018-03-01

    Dissolved black carbon (DBC) is ubiquitous in aquatic systems, being an important subgroup of the dissolved organic matter (DOM) pool. Nevertheless, its aquatic photoactivity remains largely unknown. In this study, a range of spectroscopic indices of DBC and humic substance (HS) samples were determined using UV-Vis spectroscopy, fluorescence spectroscopy, and proton nuclear magnetic resonance. DBC can be readily differentiated from HS using spectroscopic indices. It has lower average molecular weight, but higher aromaticity and lignin content. The apparent singlet oxygen quantum yield (Φ singlet oxygen ) of DBC under simulated sunlight varies from 3.46% to 6.13%, significantly higher than HS, 1.26%-3.57%, suggesting that DBC is the more photoactive component in the DOM pool. Despite drastically different formation processes and structural properties, the Φ singlet oxygen of DBC and HS can be well predicted by the same simple linear regression models using optical indices including spectral slope coefficient (S 275-295 ) and absorbance ratio (E 2 /E 3 ) which are proxies for the abundance of singlet oxygen sensitizers and for the significance of intramolecular charge transfer interactions. The regression models can be potentially used to assess the photoactivity of DOM at large scales with in situ water spectrophotometry or satellite remote sensing. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Photochemical fate of a mixture of emerging pollutants in the presence of humic substances.

    Science.gov (United States)

    Carlos, Luciano; Mártire, Daniel O; Gonzalez, Mónica C; Gomis, Juan; Bernabeu, Antonio; Amat, Ana M; Arques, Antonio

    2012-10-01

    The photodegradation of a mixture of the emerging pollutants (EPs) clofibric acid, amoxicillin, acetamiprid, acetaminophen, carbamazepine, and caffeine was studied under irradiation with a xenon lamp. The quantum efficiencies of the EPs were determined when irradiated individually. Experiments with the mixture of the EPs showed that indirect photoprocesses attributable to interaction between EPs can either enhance the photodegradation rate by photosensitization or decrease it by quenching processes. The addition of humic substances (HS) to the solutions resulted in an increase of indirect photoprocesses with higher effects on acetaminophen and carbamazepine; this was more remarkable when a filter was used to cut off radiation in the range 280-295 nm. Experiments carried out with chemical probes indicated that the triplet excited states of HS play a major role in the photosensitization process, although the contribution of other species cannot be completely ruled out. Additionally, V. fischeri toxicity tests showed a synergistic effect produced by the mixture of EPs before irradiation. Photodegradation resulted in an enhanced toxicity of the solution at the initial steps of the process, which was associated both with synergistic effects and with the formation of toxic photodegradation by-products of clofibric acid. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Investigating chloroperoxidase-catalyzed formation of chloroform from humic substances using stable chlorine isotope analysis.

    Science.gov (United States)

    Breider, Florian; Hunkeler, Daniel

    2014-01-01

    Chloroperoxidase (CPO) is suspected to play an important role in the biosynthesis of natural chloroform. The aims of the present study are to evaluate the variability of the δ(37)Cl value of naturally produced chloroform and to better understand the reaction steps that control the chlorine isotope signature of chloroform. The isotope analyses have shown that the chlorination of the humic substances (HS) in the presence of high H3O(+) and Cl(-) concentrations induces a large apparent kinetic isotope effect (AKIE = 1.010-1.018) likely associated with the transfer of chlorine between two heavy atoms, whereas in the presence of low H3O(+) and Cl(-) concentrations, the formation of chloroform induces a smaller AKIE (1.005-1.006) likely associated with the formation of an HOCl-ferriprotoporphyrin IX intermediate. As the concentration of H3O(+) and Cl(-) in soils are generally at submillimolar levels, the formation of the HOCl-ferriprotoporphyrin IX intermediate is likely rate-limiting in a terrestrial environment. Given that the δ(37)Cl values of naturally occurring chloride tend to range between -1 and +1‰, the δ(37)Cl value of natural chloroform should vary between -5‰ and -8‰. As the median δ(37)Cl value of industrial chloroform is -3.0‰, the present study suggests that chlorine isotopic composition of chloroform might be used to discriminate industrial and natural sources in the environment.

  19. Influence of Extractant and Soil Type on Molecular Characteristics of Humic Substances From Two Brazilian Soils

    Directory of Open Access Journals (Sweden)

    Dick Deborah Pinheiro

    1999-01-01

    Full Text Available In a previous study it was observed that humic substances (HS extracted with NaOH solution and with Na4P2O7 solution presented different molecular weights, and also that the extracted HS yield by each method varied between an Oxisol and a Mollisol from South Brazil. In the present study, we further investigated the organic matter in these soils by characterizing HS extracted with 0.5 mol L-1 NaOH and with neutral 0.15 mol L-1 Na4P2O7 solutions from the above mentioned samples, using elemental analysis and nuclear magnetic ressonance spectroscopy (liquid state ¹H- and 13C-NMR, and by relating the molecular differences to the extraction method and soil type. HS extracted with pyrophosphate were more humified, showing a higher aromaticity and higher carboxylic content. The NaOH-extracted HS were more aliphatic and contained a higher O-alkyl proportion, which is indicative of a less humified nature than the pyrophosphate-extracted HS.

  20. Characterization of the interactions between endocrine disruptors and aquatic humic substances from tropical rivers

    Energy Technology Data Exchange (ETDEWEB)

    Botero, Wander G. [Universidade Federal de Alagoas (UFAL), Arapiraca, AL (Brazil); Oliveira, Luciana C. de [Universidade Federal de Sao Carlos (UFSCar), Sorocaba, SP (Brazil); Cunha, Bruno B.; Oliveira, Lilian K. de; Goveia, Danielle; Fraceto, Leonardo F.; Rosa, Andre Henrique, E-mail: ahrosa@sorocaba.unesp.b [UNESP, Sorocaba, SP (Brazil). Dept. de Engenharia do Meio Ambiente; Rocha, Julio Cesar [UNESP, Araraquara, SP (Brazil). Inst. de Quimica. Dept. de Quimica Analitica

    2011-07-01

    Interactions between two endocrine disruptors (ED) and aquatic humic substances (AHS) from tropical rivers were studied using an ultrafiltration system equipped with a 1 kDa cut-off cellulose membrane to separate free ED from the fraction bound in the AHS. Quantification of 17{alpha}-ethynylestradiol and bisphenol A was performed using gas chromatography-mass spectrometry (GC-MS). The times required for establishment of equilibrium between the AHS and the ED were ca. 30 min, and complexation capacities for 17{alpha}-ethynylestradiol and bisphenol A were 18.53 and 2.07 mg g{sup -1} TOC, respectively. The greater interaction of AHS with 17{alpha}-ethynylestradiol, compared to bisphenol A, was due to the presence of hydrogen in the structure of 17{alpha}-ethynylestradiol, which could interact with ionized oxygenated groups of the AHS. The results indicate that AHS can strongly influence the transport and reactivity of endocrine disruptors in aquatic systems. (author)

  1. Impact of the Interaction between Aquatic Humic Substances and Algal Organic Matter on the Fouling of a Ceramic Microfiltration Membrane

    Directory of Open Access Journals (Sweden)

    Xiaolei Zhang

    2018-02-01

    Full Text Available The influence of the interaction between aquatic humic substances and the algal organic matter (AOM derived from Microcystis aeruginosa on the fouling of a ceramic microfiltration (MF membrane was studied. AOM alone resulted in a significantly greater flux decline compared with Suwannee River humic acid (HA, and fulvic acid (FA. The mixture of AOM with HA and FA exhibited a similar flux pattern as the AOM alone in the single-cycle filtration tests, indicating the flux decline may be predominantly controlled by the AOM in the early filtration cycles. The mixtures resulted in a marked increase in irreversible fouling resistance compared with all individual feed solutions. An increase in zeta potential was observed for the mixtures (becoming more negatively charged, which was in accordance with the increased reversible fouling resistance resulting from enhanced electrostatic repulsion between the organic compounds and the negatively-charged ceramic membrane. Dynamic light scattering (DLS and size exclusion chromatography analyses showed an apparent increase in molecular size for the AOM-humics mixtures, and some UV-absorbing molecules in the humics appeared to participate in the formation of larger aggregates with the AOM, which led to greater extent of pore plugging and hence resulted in higher irreversible fouling resistance.

  2. Quantitative evaluation of noncovalent interactions between glyphosate and dissolved humic substances by NMR spectroscopy.

    Science.gov (United States)

    Mazzei, Pierluigi; Piccolo, Alessandro

    2012-06-05

    Interactions of glyphosate (N-phosphonomethylglycine) herbicide (GLY) with soluble fulvic acids (FAs) and humic acids (HAs) at pH 5.2 and 7 were studied by (1)H and (31)P NMR spectroscopy. Increasing concentrations of soluble humic matter determined broadening and chemical shift drifts of proton and phosphorus GLY signals, thereby indicating the occurrence of weak interactions between GLY and humic superstructures. Binding was larger for FAs and pH 5.2 than for HAs and pH 7, thus suggesting formation of hydrogen bonds between GLY carboxyl and phosphonate groups and protonated oxygen functions in humic matter. Changes in relaxation and correlation times of (1)H and (31)P signals and saturation transfer difference NMR experiments confirmed the noncovalent nature of GLY-humic interactions. Diffusion-ordered NMR spectra allowed calculation of the glyphosate fraction bound to humic superstructures and association constants (K(a)) and Gibbs free energies of transfer for GLY-humic complex formation at both pH values. These values showed that noncovalent interactions occurred most effectively with FAs and at pH 5.2. Our findings indicated that glyphosate may spontaneously and significantly bind to soluble humic matter by noncovalent interactions at slightly acidic pH and, thus, potentially pollute natural water bodies by moving through soil profiles in complexes with dissolved humus.

  3. Estimation of Uptake of Humic Substances from Different Sources by Escherichia coli Cells under Optimum and Salt Stress Conditions by Use of Tritium-Labeled Humic Materials▿

    Science.gov (United States)

    Kulikova, Natalia A.; Perminova, Irina V.; Badun, Gennady A.; Chernysheva, Maria G.; Koroleva, Olga V.; Tsvetkova, Eugenia A.

    2010-01-01

    The primary goal of this paper is to demonstrate potential strengths of the use of tritium-labeled humic substances (HS) to quantify their interaction with living cells under various conditions. A novel approach was taken to study the interaction between a model microorganism and the labeled humic material. The bacterium Escherichia coli was used as a model microorganism. Salt stress was used to study interactions of HS with living cells under nonoptimum conditions. Six tritium-labeled samples of HS originating from coal, peat, and soil were examined. To quantify their interaction with E. coli cells, bioconcentration factors (BCF) were calculated and the amount of HS that penetrated into the cell interior was determined, and the liquid scintillation counting technique was used as well. The BCF values under optimum conditions varied from 0.9 to 13.1 liters kg−1 of cell biomass, whereas under salt stress conditions the range of corresponding values increased substantially and accounted for 0.2 to 130 liters kg−1. The measured amounts of HS that penetrated into the cells were 23 to 167 mg and 25 to 465 mg HS per kg of cell biomass under optimum and salt stress conditions, respectively. This finding indicated increased penetration of HS into E. coli cells under salt stress. PMID:20639375

  4. Adsorption of insecticidal Cry1Ab protein to humic substances. 2. Influence of humic and fulvic acid charge and polarity characteristics.

    Science.gov (United States)

    Tomaszewski, Jeanne E; Madliger, Michael; Pedersen, Joel A; Schwarzenbach, René P; Sander, Michael

    2012-09-18

    Assessing the fate and potential risks of transgenic Cry proteins in soils requires understanding of Cry protein adsorption to soil particles. The companion paper provided evidence that patch-controlled electrostatic attraction (PCEA) and the hydrophobic effect contributed to Cry1Ab protein adsorption to an apolar humic acid (HA). Here, we further assess the relative importance of these contributions by comparing Cry1Ab adsorption to seven humic substances varying in polarity and charge, at different solution pH and ionic strength, I. Cry1Ab adsorption to relatively apolar HAs at I = 50 mM exhibited rapid initial rates, was extensive, and was only partially reversible at pH 5-8, whereas adsorption to more polar fulvic acids was weak and reversible or absent at pH >6. The decrease in adsorption with increasing HS polarity at all tested pH strongly supports a large contribution from the hydrophobic effect to adsorption, particularly at I = 50 mM when PCEA was effectively screened. Using insect bioassays, we further show that Cry1Ab adsorbed to a selected HA retained full insecticidal activity. Our results highlight the need to consider adsorption to soil organic matter in models that assess the fate of Cry proteins in soils.

  5. Application of the NICA Donnan model to the complexation of radionuclides by humic substances

    Energy Technology Data Exchange (ETDEWEB)

    Marang, L.; Reiller, P. [CEA/DEN/DPC/SECR/LSRM, Batiment 391, F-91191 Gif-sur-Yvette Cedex (France); Benedetti, M.F. [Laboratoire de Geochimie des Eaux (LGE), Universite Denis Diderot - Paris 7 and IPGP, 75251 PARIS CEDEX 05 (France)

    2005-07-01

    Full text of publication follows: The comprehension of radionuclide migration processes requires an extensive knowledge of their chemical forms with regard to radioactive waste management purposes. It is now recognized that natural organic matter (NOM) and particularly humic substances (HS) influences speciation and migration properties of metallic cations in general and of radionuclides in particular. From the different models describing the complexation of cation binding by HS, the non-ideal competitive adsorption model (NICA-Donnan) takes into consideration the binding heterogeneity of NOM, the competition between specifically bound ions (protons and metal) and electrostatic effects which give rise to ionic strength effects and the non-specific binding of counter-ions [1]. This model has not, or scarcely, been used yet for the description of relevant radionuclides like Co{sup 2+}, Ni{sup 2+} and more hydrolyzable cations like Eu{sup 3+}, UO{sub 2}{sup 2+} with HS [2] The Donnan Membrane Technique (DMT) is used for the measurement of free metal ion concentration at different pH and metal to organic matter ratio needed to calibrate the model. This technique is based on the use of a semi-permeable, negatively charged, cation exchange membrane that separates free metal cations from complexed ones. The concentration of free and bound metal ions on each side of the membrane is detected by inductively coupled plasma-mass spectrometry (ICP-MS). The NICA-Donnan parameters will be determined for each metal considered. Then, the ability of the model to predict competition between radionuclides and majors ions will be tested. [1] Kinniburgh, D. G., van Riemsdijk, W. H., Koopal, L. K., Borkovec, M., Benedetti, M. F., Avena, M. J.: Ion binding to natural organic matter: competition, heterogeneity, stoichiometry and thermodynamic consistency. Colloids Surf. A. 151, 147 (1999). [2] Saito, T., Nagasaki, S., Tanaka, S., Koopal, L. K.: Application of the NICA-Donnan model for

  6. Electropulse treatment of water solution of humic substances in a layer iron granules in process of water treatment

    Science.gov (United States)

    Lobanova, G. L.; Yurmazova, T. A.; Shiyan, L. N.; Machekhina, K. I.

    2016-02-01

    The present work is a part of a continuations study of the physical and chemical processes complex in natural waters containing humic-type organic substances at the influence of pulsed electrical discharges in a layer of iron pellets. The study of humic substances processing in the iron granules layer by means of pulsed electric discharge for the purpose of water purification from organic compounds humic origin from natural water of the northern regions of Russia is relevant for the water treatment technologies. In case of molar humate sodium - iron ions (II) at the ratio 2:3, reduction of solution colour and chemical oxygen demand occur due to the humate sodium ions and iron (II) participation in oxidation-reduction reactions followed by coagulation insoluble compounds formation at a pH of 6.5. In order to achieve this molar ratio and the time of pulsed electric discharge, equal to 10 seconds is experimentally identified. The role of secondary processes that occur after disconnection of the discharge is shown. The time of contact in active erosion products with sodium humate, equal to 1 hour is established. During this time, the value of permanganate oxidation and iron concentration in solution achieves the value of maximum permissible concentrations and further contact time increase does not lead to the controlled parameters change.

  7. Influence of mineral colloids and humic substances on uranium(VI) transport in water-saturated geologic porous media.

    Science.gov (United States)

    Wang, Qing; Cheng, Tao; Wu, Yang

    2014-12-01

    Mineral colloids and humic substances often co-exist in subsurface environment and substantially influence uranium (U) transport. However, the combined effects of mineral colloids and humic substances on U transport are not clear. This study is aimed at quantifying U transport and elucidating geochemical processes that control U transport when both mineral colloids and humic acid (HA) are present. U-spiked solutions/suspensions were injected into water-saturated sand columns, and U and colloid concentrations in column effluent were monitored. We found that HA promoted U transport via (i) formation of aqueous U-HA complexes, and (ii) competition against aqueous U for surface sites on transport media. Illite colloids had no influence on U transport at pH5 in the absence of HA due to low mobility of the colloids. At pH9, U desorbed from mobile illite and the presence of illite decreased U transport. At pH5, high U transport occurred when both illite colloids and HA were present, which was attributed to enhanced U adsorption to illite colloids via formation of ternary illite-HA-U surface complexes, and enhanced illite transport due to HA attachment to illite and transport media. This study demonstrates that the combined effects of mineral colloids and HA on contaminant transport is different from simple addition of the individual effect. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Effect of Mineral and Humic Substances on Tailing Soil Properties and Nutrient Uptake by Pennisetum purpureum Schumach

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    Adhe Phoppy Wira Etika

    2015-05-01

    Full Text Available Tin mining produces a by-product sand tailing from soil leaching with characteristic low pH and total organic carbon, and can be reclaimed by providing a suitable ameliorant. When available in situ, ameliorant materials can be economically used as they are required in large amounts. Fortunately, Bangka Belitung has sample stock of such kaolinite-rich minerals that can be utilized for improving soil chemical properties. Extracted organic materials, such as humic substances, can also be utilized as they influence the complex soil reactions, and promote plant growth. Thus, this study aimed to assess the effects of mineral, humic materials and interaction of both material on soil chemical properties and nutrient uptake of Pennisetum purpureum Schumach. A completely randomized design with 2 factors and 3 replications each was employed. Factor 1 was mineral matter is 0; 420; 840; 1.260 Mg ha-1 while Factor 2 was humic material is 0; 0.46; 0.92; 1.38 kg C ha-1. Air-dried samples of tailing were applied with oil palm compost then mixed evenly with mineral and humic materials. Penissetum purpureum Schumach was planted after 4 weeks incubation, and maintained for another 4 weeks. The results demonstrated that the addition of mineral matter significantly increased soil organic carbon content, total N, exchangeable K, Fe, Mn and boosted nutrient - total Ca, Mg and Mn – uptake of the plant. But the application of humic material increased only soil organic carbon content. The interaction of both materials only lowered soil pH.

  9. Plant biostimulants: physiological responses induced by protein hydrolyzed-based products and humic substances in plant metabolism

    Directory of Open Access Journals (Sweden)

    Serenella Nardi

    2016-02-01

    Full Text Available ABSTRACT In recent years, the use of biostimulants in sustainable agriculture has been growing. Biostimulants can be obtained from different organic materials and include humic substances (HS, complex organic materials, beneficial chemical elements, peptides and amino acids, inorganic salts, seaweed extracts, chitin and chitosan derivatives, antitranspirants, amino acids and other N-containing substances. The application of biostimulants to plants leads to higher content of nutrients in their tissue and positive metabolic changes. For these reasons, the development of new biostimulants has become a focus of scientific interest. Among their different functions, biostimulants influence plant growth and nitrogen metabolism, especially because of their content in hormones and other signalling molecules. A significant increase in root hair length and density is often observed in plants treated with biostimulants, suggesting that these substances induce a “nutrient acquisition response” that favors nutrient uptake in plants via an increase in the absorptive surface area. Furthermore, biostimulants positively influence the activity and gene expression of enzymes functioning in the primary and secondary plant metabolism. This article reviews the current literature on two main classes of biostimulants: humic substances and protein-based biostimulants. The characteristic of these biostimulants and their effects on plants are thoroughly described.

  10. Influence of humic substances on enhanced remediation of soil polluted by a copper-nickel smelter

    Science.gov (United States)

    Tregubova, Polina; Turbaevskaya, Valeria; Korneecheva, Mariya; Kupriyanova, Yuliya; Koptsik, Galina

    2017-04-01

    The problem of technogenic contamination through the anthropogenic activity is quite urgent nowadays. Long-term air pollution with sulphur dioxide and heavy metals (HM) by injuring vegetation and inhibition of plant and soil microorganisms growth and activity causes appearance of the barren areas - highly damaged eroded ecosystems requiring remediation. There are a lot of remediation ways, but an appropriate restoration method, which does not expensive, does not demand special technical support and corresponds to the natural conditions of soil development is still open to question. We suggest application of exogenous humic substances as the possible environmentally friendly solution of HM toxicity problem and soil health restoration. Using of humates can result in the improvement of soil properties, localization of contamination by decreasing of HM mobility and bioavailability through binding them in relatively immobile complexes, and in stabilization of organic pool. But practice of scientific society as well as our previous investigations demonstrates ambiguous influence of exogenic humic substances on the behavior of HM depending on origin, doses, molecular weight of organic matter and state of microorganisms. In this research we have provided series of short-term (45 days) experiments dedicated to the evaluation of suitable doses of humates of different origin - coal and peat - inoculated by nitrogen fixers and mycorhizae-forming fungi in comparison with lime and NPK-fertilizer on the properties of contaminated soil and mobility of HM. The object of investigation was Al-Fe-humus abrazems from the vicinity of mining-and-metallurgical integrated work located in the Kola Peninsula, Russia. This soil is characterized by the absence of vegetation, complete loss of the organic horizon in result of the erosion processes, low pH (pH H2O 4.1-5.0), low exchangeable acidity (0.8-1.6 cmolc/kg), and depletion of organic mater (content of total carbon is 0.3-0.5%). The main

  11. Compost and humic substance effects on soil parameters of Vitis vinifera L cv Thompson seedless

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    Paola Fincheira-Robles

    2016-01-01

    Full Text Available The use of organic amendments is common under the concept of integrated nutrient management (INM in Vi tis vinifera (Table grape to improve plant and soil quality. The objective of this study was to evaluate compost (C and humic substances (HS mixed with mineral fertilizer (MF in an INM program of V. vinifera cv Thompson seedless. The chemical, biochemi cal and microbiological parameters were evaluated in soil on 1 - year - old V. vinifera plants growing on Alfisol soil. Five treatments and control were evaluated: (T 1 C+MF, (T 2 HS+MF, (T 3 C, (T 4 HS, (T 5 MF and (T 6 absolute control. The results indicate d that the application of C and HS, increased β glucosidase and dehydrogenase activities, reaching values of 90.2 μg p - nitrophenol g - 1 h - 1 and 9.1 μg de TFP g - 1 24h - 1 , respectively . In addition, pH was similar in all treatments while electrical conductivity increased with application of mineral and orga nic amendments, reaching 0.41dS m - 1 in T 2 (HS+MF . Furthermore, yeast concentration increased with organic amendments or mineral. Correlation analysis indicated significant and positive relationships between PO 4 - P concentration with MF (0.579 and C (0.431 and nitrogen with MF (0.868. These results support that INM, which combines mineral fertilization and organic amendments, improve positive changes in chemical soil properties and C cycling measured in terms of enzymatic activity in V. vinifera .

  12. The impact of interactions between algal organic matter and humic substances on coagulation.

    Science.gov (United States)

    Pivokonsky, Martin; Naceradska, Jana; Brabenec, Tomas; Novotna, Katerina; Baresova, Magdalena; Janda, Vaclav

    2015-11-01

    This study focuses on the effects of molecular interactions between two natural organic matter (NOM) fractions, peptides/proteins derived from cyanobacterium Microcystis aeruginosa (MA proteins) and peat humic substances (HS), on their removal by coagulation. Coagulation behaviour was studied by the jar tests with MA protein/HS mixtures and with single compounds (MA proteins or HS). Aluminium sulphate was used as a coagulant. Besides MA proteins, bovine serum albumin (BSA) was used as a model protein. For the MA protein/HS mixture, the removal rates were higher (80% versus 65%) and the dose of coagulant substantially lower (2.8 versus 5.5 mg L(-1) Al) than for coagulation of single HS, indicating the positive effect of protein-HS interactions on the coagulation process. The optimum coagulation pH was 5.2-6.7 for MA proteins and 5.5-6 for HS by alum. The optimum pH for the removal of MA protein/HS mixture ranged between pH 5.5-6.2, where the charge neutralization of negatively charged acidic functional groups of organic molecules by positively charged coagulant hydroxopolymers lead to coagulation. MA proteins interacted with HS, probably through hydrophobic, dipole-dipole and electrostatic interactions, even in the absence the coagulant. These interactions are likely to occur within a wide pH range, but they result in coagulation only at low pH values (pH organic content in source water due to the release of algae products may not necessarily entail deterioration of the coagulation process and a rise in coagulant demand. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. The Effect of Humic Acid Substances on the Thyroid Function and Structure in Lead Poisoning

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    A Sahin

    Full Text Available ABSTRACT Lead (Pb is a heavy metal, which adversely affects thyroid gland function and structure. Due to its high molecular weight and abundant functional groups, humic acid substances (HAS can form chelates with heavy metals. The experiment was conducted to evaluate the prophylactic effect of HAS on thyroid hormone levels and histopathological lesions of laying hens exposed to lead (Pb poisoning. After a week of adaptation, 192 Lohmann White laying hens (25 weeks of age were fed one of four diets: a basal diet (BD or the BD with HAS (0.15%, with Pb (0.3 g/kg, or with both. Experimental groups were replicated in 12 cages, with four hens each. Pb poisoning did not alter triiodothyronine (FT3; 3.22 ± 0.20 ng/dL or thyroxine (FT4; 0.71 ± 0.08 ng/dL concentrations, but caused a 167% increase in thyroid stimulating hormone (TSH concentration. HAS supplementation returned the high TSH levels of hens exposed to Pb poisoning to normal values. Degenerative changes in the epithelial cells of the thyroid gland of the hens exposed to Pb poisoning were evidenced. Connective tissue cells in the interfollicular area and total amount of colloids with partially atrophic follicles were observed. These histopathological findings were less severe when HAS was added to the diet. In conclusion, HAS alleviates the effects of Pb poisoning on thyroid gland function and structure, possibly preventing its internalization by the tissue by forming chelates and exerting anti-inflammatory effects.

  14. On the control of copper colloidal distribution by humic substances in the Penzé estuary.

    Science.gov (United States)

    Waeles, Matthieu; Tanguy, Virginie; Riso, Ricardo D

    2015-01-01

    In this study, we investigated the variations of colloidal Cu in a temperate macrotidal estuarine system (Penzé, NW France). The originality of this work resides on examining seven colloidal/dissolved fractions at seven different periods of the year whereas previous studies on estuaries generally considered two or three fractions and were focused on a unique survey. A high proportion of Cu (∼90%) was generally found as colloids (5 kDa-0.45 μm) throughout the salinity gradient with divergent size distributions being observed over the seasonal cycle. This consisted essentially in two contrasted periods, i.e. winter-spring with a greater association of Cu with high molecular weight (HMW) compounds (50 kDa-0.45 μm) and summer-autumn with Cu being found mainly as low molecular weight (LMW) forms (5-50 kDa). The comparison of Cu with humic substances (HS) data allowed to us to highlight the importance of the pedogenic refractory organic matter in controlling the concentrations and the size distribution of Cu in the estuary. In the mixing zone, Cu behaved conservative in autumn and winter but important additions of HMW compounds were observed in spring in the lower estuary as the result of particulate organic matter degradation in the sediment. Although HS appears to be the background chelators of Cu in the systems, the strong benthic inputs occurring in spring may be of different (biotic) origin and may be in part responsible for the higher association of Cu with HMW compounds. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Pb(II) binding to humic substances: an equilibrium and spectroscopic study

    OpenAIRE

    Orsetti, Silvia; Marco Brown, Jose Luis; Andrade, Estela M.; Molina,Fernando Víctor

    2016-01-01

    The binding of Pb(II) to humic acids is studied through an approach combining equilibrium and spectroscopic measurements. The methods employed are potentiometric and fluorometric titrations, fluorescence excitation−emission matrices (EEM) and IR spectroscopy. Potentiometric titration curves are analyzed using the NICA equations and an electrostatic model treating the humic particles as an elastic polyelectrolyte network. EEMs are analyzed using parallel factor analysis, decomposing the s...

  16. Influence of dissolved humic substances on the mass transfer of organic compounds across the air-water interface.

    Science.gov (United States)

    Ramus, Ksenia; Kopinke, Frank-Dieter; Georgi, Anett

    2012-01-01

    The effect of dissolved humic substances (DHS) on the rate of water-gas exchange of two volatile organic compounds was studied under various conditions of agitation intensity, solution pH and ionic strength. Mass-transfer coefficients were determined from the rate of depletion of model compounds from an apparatus containing a stirred aqueous solution with continuous purging of the headspace above the solution (dynamic system). Under these conditions, the overall transfer rate is controlled by the mass-transfer resistance on the water side of the water-gas interface. The experimental results show that the presence of DHS hinders the transport of the organic molecules from the water into the gas phase under all investigated conditions. Mass-transfer coefficients were significantly reduced even by low, environmentally relevant concentrations of DHS. The retardation effect increased with increasing DHS concentration. The magnitude of the retardation effect on water-gas exchange was compared for Suwannee River fulvic and humic acids, a commercially available leonardite humic acid and two synthetic surfactants. The observed results are in accordance with the concept of hydrodynamic effects. Surface pressure forces due to surface film formation change the hydrodynamic characteristics of water motion at the water-air interface and thus impede surface renewal. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Pb(II) binding to humic substances: an equilibrium and spectroscopic study.

    Science.gov (United States)

    Orsetti, Silvia; Marco-Brown, Jose L; Andrade, Estela M; Molina, Fernando V

    2013-08-06

    The binding of Pb(II) to humic acids is studied through an approach combining equilibrium and spectroscopic measurements. The methods employed are potentiometric and fluorometric titrations, fluorescence excitation-emission matrices (EEM) and IR spectroscopy. Potentiometric titration curves are analyzed using the NICA equations and an electrostatic model treating the humic particles as an elastic polyelectrolyte network. EEMs are analyzed using parallel factor analysis, decomposing the signal in its independent components and finding their dependence on Pb(II) activity. Potentiometric results are consistent with bimodal affinity distributions for Pb(II) binding, whereas fluorometric titrations are explained by monomodal distributions. EEM analysis is consistent with three independent components in the humic fluorescence response, which are assigned to moieties with different degree of aromaticity. All three components show a similar quenching behavior upon Pb(II) binding, saturating at relatively low Pb(II) concentrations. This is attributed to metal ion induced aggregation of humic molecules, resulting in the interaction between the aromatic groups responsible for fluorescence; this is also consistent with IR spectroscopy results. The observed behavior is interpreted considering that initial metal binding (observed as strongly binding sites), correspond to bi- or multidentate complexation to carboxylate groups, including binding between groups of different humic molecules, promoting aggregation; further metal ions (observed as weakly binding sites) bind to single ligand groups.

  18. Complexation humic substances of soils with metal ions as the main way migration of matals from soil to water

    Science.gov (United States)

    Dinu, Marina

    2013-04-01

    Organic matter (OM) of natural waters can bind with the ions metals (IM) entering the system, thus reducing their toxic properties. OM in water consists predominantly (up to 80%) of humic acids (HA), represented by highmolecular, dyed, polyfunctional compounds. The natural-climatic zones feature various ratios of fulvic (FA) and humic acids. An important specific feature of metals as contamination elements is the fact that when they occur in the environment, their potential toxicity and bioavailability depend significantly on their speciation. In recent years, lakes have been continuously enriched in hazardous elements such as Pb, Cd, Al, and Cr on a global (regional) basis. The most important organic ligands are humic matter (HM) washed out from soils in water and metals occur in natural waters as free ions, simple complexes with inorganic and organic ligands, and mineral and organic particles of molecules and ions sorbed on the surface. The occurrence of soluble metal forms in natural waters depends on the presence of organic and inorganic anions. However, direct determinations are rather difficult. The goal was the calculation and analysis of the forms of metals in the system catchment basin, based on the chemical composition of the water body and the structural features of soil humic substances (HS).We used the following analytical techniques - leaching of humic substances from soil and sample preparation (Orlov DS, 1985), the functional characteristics of humic substances - spectral analysis methods, the definition of conditional stability constants of complexes - electrochemical methods of analysis. Our results show thet HAs of selected soil types are different in functions, and these differences effect substantially the complexing process. When analyzing the results obtained in the course of spectrometric investigation of HMs in selected soil types, we determined the following main HA characteristics: (1) predominance of oxygen bearing groups in HM of the

  19. Contrasting cellular stress responses of Baikalian and Palearctic amphipods upon exposure to humic substances: environmental implications.

    Science.gov (United States)

    Protopopova, Marina V; Pavlichenko, Vasiliy V; Menzel, Ralph; Putschew, Anke; Luckenbach, Till; Steinberg, Christian E W

    2014-12-01

    The species-rich, endemic amphipod fauna of Lake Baikal does not overlap with the common Palearctic fauna; however, the underlying mechanisms for this are poorly understood. Considering that Palearctic lakes have a higher relative input of natural organic compounds with a dominance of humic substances (HSs) than Lake Baikal, we addressed the question whether HSs are candidate factors that affect the different species compositions in these water bodies. We hypothesized that interspecies differences in stress defense might reveal that Baikalian amphipods are inferior to Palearctic amphipods in dealing with HS-mediated stress. In this study, two key mechanisms of general stress response were examined: heat-shock protein 70 (HSP70) and multixenobiotic resistance-associated transporters (ABCB1). The results of quantitative polymerase chain reaction (qPCR) showed that the basal levels (in 3-day acclimated animals) of hsp70 and abcb1 transcripts were lower in Baikalian species (Eulimnogammarus cyaneus, Eulimnogammarus verrucosus, Eulimnogammarus vittatus-the most typical littoral species) than in the Palearctic amphipod (Gammarus lacustris-the only Palearctic species distributed in the Baikalian region). In the amphipods, the stress response was induced using HSs at 10 mg L(-1) dissolved organic carbon, which was higher than in sampling sites of the studied species, but well within the range (3-10 mg L(-1)) in the surrounding water bodies populated by G. lacustris. The results of qPCR and western blotting (n = 5) showed that HS exposure led to increased hsp70/abcb1 transcripts and HSP70 protein levels in G. lacustris, whereas these transcript levels remained constant or decreased in the Baikalian species. The decreased level of stress transcripts is probably not able to confer an effective tolerance to Baikalian species against further environmental stressors in conditions with elevated HS levels. Thus, our results suggest a greater robustness of Palearctic amphipods and

  20. Facilitated transport of titanium dioxide nanoparticles by humic substances in saturated porous media under acidic conditions

    Science.gov (United States)

    Zhang, Ruichang; Zhang, Haibo; Tu, Chen; Hu, Xuefeng; Li, Lianzhen; Luo, Yongming; Christie, Peter

    2015-04-01

    The transport behavior of titanium dioxide nanoparticles (TiO2 NPs, 30 nm in diameter) was studied in well-defined porous media composed of clean quartz sand over a range of solution chemistry under acidic conditions. Transport of TiO2 NPs was dramatically enhanced by humic substances (HS) at acidic pH (4.0, 5.0 and 6.0), even at a low HS concentration of 0.5 mg L-1. Facilitated transport of TiO2 NPs was likely attributable to the increased stability of TiO2 NPs and repulsive interaction between TiO2 NPs and quartz sands due to the adsorbed HS. The mobility of TiO2 NPs was also increased with increasing pH from 4.0 to 6.0. Although transport of TiO2 NPs was insensitive to low ionic strength, it was significantly inhibited by high concentrations of NaCl and CaCl2. In addition, calculated Derjaguin-Landau-Verwey-Overbeek (DLVO) interaction energy indicated that high energy barriers were responsible for the high mobility of TiO2 NPs, while the secondary energy minimum could play an important role in the retention of TiO2 NPs at 100 mmol L-1 NaCl. Straining and gravitational settlement of larger TiO2 NPs aggregates at 1 mg L-1 HS, pH 5.0, and 2 mmol L-1 CaCl2 could be responsible for the significant retention even in the presence of high energy barriers. Moreover, more favorable interaction between approaching TiO2 NPs and TiO2 NPs that had been already deposited on the collector resulted in a ripening-shape breakthrough curve at 2 mmol L-1 CaCl2. Overall, a combination of mechanisms including DLVO-type force, straining, and physical filtration was involved in the retention of TiO2 NPs over the range of solution chemistry examined in this study.

  1. Comparison between stability constants of cadmium and lead complexes with humic substances of different molecular weight isolated from Baltic Sea water

    Directory of Open Access Journals (Sweden)

    Waldemar Grzybowski

    2000-12-01

    Full Text Available The complexation of cadmium and lead with humic substances was studied using differential pulse anodic stripping voltammetry and a standard addition technique. The titration was done for humic substances of different molecular weight that had been isolated from seawater and subsequently redissolved in organic-free seawater. The different molecular weight fractions were obtained by ultrafiltration using 1000 D (Dalton, 5000 D and 10 000 D pore size filters. Comparison of the calculated stability constants suggests that the strengths of lead complexes in the analysed fractions are similar and that cadmium is complexed by the fraction smaller than 1000 D.

  2. Scientific writing seminar for early-stage investigators in substance abuse research.

    Science.gov (United States)

    Guydish, Joseph; Masson, Carmen; Flentje, Annesa; Shopshire, Michael; Sorensen, James L

    2016-01-01

    There is little information on how to increase the scientific writing productivity of early-stage investigators in the addictions field. A scientific writing seminar is presented in this article, aiming to encourage manuscript writing and dissemination of addiction research, and outcomes are reported for 14 years of the seminar. In 14 years, there were 113 postdoctoral fellow enrollments in a 6-month writing seminar. Records of submission and publication rates of manuscripts were collected for 14 cohorts. Of the 113 participant enrollments, 97 (86%) submitted a manuscript for publication, and 87 participants (77%) published their manuscript. A scientific writing seminar may benefit writing productivity, but more research is needed to compare this training model with other existing models.

  3. Fixation and transport of uranium by humic substances (1962); Fixation et transport de l'uranium par les substances humiques (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Martin, J. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1962-03-15

    One enter upon the study of the part taken by organic substances in ores that contain uranium in a disseminated form, without mineralization, being considered the reaction between uranium and humus. 'Humic acids' are extracted from the peat by ammonia. By the fact of their ability to cationic exchange, these are forming humates with metal cations; monovalent humates, normally soluble in water, can become insoluble after treatment of humic acids with methanal. The polyvalent humates are insoluble in water, especially humates of U (IV) and uranyl U (VI). Action of Li, Na, K, Mg, Ca uranyl carbonates solutions on the humic acids results in the formation of humates containing uranyl and the other cation. 100 g of humic acids give a fixation of no more than 38 g of uranium as uranyl. In contact with uraniferous weakly concentrated solutions, they fix 4 to 8 g according to pH, with a yield in the extraction greater than 95 per cent. The action of a sodium humate solution on a humate of uranyl give a solution containing a soluble sodium and uranyl humate. The solution is precipitated at various degrees by the polyvalent cations and insoluble humic substances. In all cases, the fixation of uranium with such prepared humic acids corresponds to a chemisorption of uranyl cations. (author) [French] L'etude du role des matieres organiques dans les minerais contenant de l'uranium sous une forme disseminee, sans mineralisation, est abordee en envisageant les reactions de l'uranium et de l'humus. Des 'acides humiques' sont extraits de la tourbe par l'ammoniaque. Par leur capacite d'echange cationique, ils forment des humates avec les cations metalliques; les humates de metaux monovalents, normalement solubles dans l'eau, peuvent etre rendus insolubles apres traitement des acides humiques par le methanal. Les humates de metaux plurivalents sont insolubles dans l'eau, en particulier ceux de U (IV) et d'uranyle U (VI

  4. Addition of a worm leachate as source of humic substances in the drinking water of broiler chickens.

    Science.gov (United States)

    Gomez-Rosales, S; de L Angeles, M

    2015-02-01

    The objective of this research was to evaluate the growth performance, the apparent ileal digestibility of nitrogen and energy, the retention of nutrients and the apparent metabolizable energy corrected to zero nitrogen retention (AMEn) in broiler chickens supplemented with increasing doses of a worm leachate (WL) as a source of humic substances (HS) in the drinking water. In Exp. 1, 140 male broilers were penned individually and assigned to four WL levels (0%, 10%, 20%, and 30%) mixed in the drinking water from 21 to 49 days of age. Water was offered in plastic bottles tied to the cage. In Exp. 2, 600 male broilers from 21 to 49 days of age housed in floor pens were assigned to three levels of WL (0%, 10%, and 20%) mixed in the drinking water. The WL was mixed with tap water in plastic containers connected by plastic tubing to bell drinkers. The results of both experiments were subjected to analysis of variance and polynomial contrasts. In Exp. 1, the daily water consumption was similar among treatments but the consumption of humic, fulvic, and total humic acids increased linearly (p<0.01) as the WL increased in the drinking water. The feed conversion (p<0.01) and the ileal digestibility of energy, the excretion of dry matter and energy, the retention of dry matter, ash and nitrogen and the AMEn showed quadratic responses (p<0.05) relative to the WL levels in drinking water. In Exp. 2, the increasing level of WL in the drinking water had quadratic effects on the final body weight, daily weight gain and feed conversion ratio (p<0.05). The addition of WL as a source of HS in the drinking water had beneficial effects on the growth performance, ileal digestibility of energy, the retention of nutrients as well on the AMEn in broiler chickens; the best results were observed when the WL was mixed at levels of 20% to 30% in the drinking water.

  5. Influence of humic substances on Co[sup 2+] sorption by a subsurface mineral separate and its mineralogic components

    Energy Technology Data Exchange (ETDEWEB)

    Zachara, J.M.; Resch, C.T.; Smith, S.C. (Pacific Northwest Laboratory, Richland, WA (United States))

    1994-01-01

    The sorption of Co[sup 2+] (10[sup [minus]6] mol/L) was measured on subsurface mineral materials in the absence and presence of a sorbed leonardite humic acid (LHA) to (1) evaluate the sorptive role of mineral-bound humic substances, and (2) establish approaches to model metal ion binding in composite materials. The subsurface materials were a <2.0 [mu]m size fraction of an ultisol saprolite (CP) and this same material treated with dithonite-citrate-bicarbonate (DCB) to remove Fe-oxides (DCP). Comparable experiments (with and without LHA) were also performed with mineral sorbents representing dominant phases in the CP separate (gibbsite, Al-geothite, and kalonite) to evaluate their potential contributions to Co sorption. The mineral-bound LHA ranged in concentration between 0.1-0.4 mg-C/m[sup 2], representing approximately 0.7% of the subsurface isolate by mass. In solid-free suspensions, the affinity of LHA for Co increased with pH and decreasing I (K[sub d] ranging 20-450 L/g). Mineral-bound LHA increased Co sorption on all the sorbents by factors of 10-60%, with the greatest augmentation noted at pH values (4.5-6.5) where (1) maximum LHA sorption occurred, and (2) Co sorption to the mineral phase was weak and dominated by ion exchange. The LHA appeared simply to augment, rather than to change the intrinsic adsorption behavior of the mineral sorbents. Accordingly, predictions of the K[sub d] for Co on the LHA-coated subsurface materials (DCP, CP) based on a linear additivity model agreed well with the experimental data, suggesting that the complex humic-mineral association acted as a noninterative sorbent mixture at low aqueous Co concentrations.

  6. Addition of a Worm Leachate as Source of Humic Substances in the Drinking Water of Broiler Chickens

    Directory of Open Access Journals (Sweden)

    S. Gomez-Rosales

    2015-02-01

    Full Text Available The objective of this research was to evaluate the growth performance, the apparent ileal digestibility of nitrogen and energy, the retention of nutrients and the apparent metabolizable energy corrected to zero nitrogen retention (AMEn in broiler chickens supplemented with increasing doses of a worm leachate (WL as a source of humic substances (HS in the drinking water. In Exp. 1, 140 male broilers were penned individually and assigned to four WL levels (0%, 10%, 20%, and 30% mixed in the drinking water from 21 to 49 days of age. Water was offered in plastic bottles tied to the cage. In Exp. 2, 600 male broilers from 21 to 49 days of age housed in floor pens were assigned to three levels of WL (0%, 10%, and 20% mixed in the drinking water. The WL was mixed with tap water in plastic containers connected by plastic tubing to bell drinkers. The results of both experiments were subjected to analysis of variance and polynomial contrasts. In Exp. 1, the daily water consumption was similar among treatments but the consumption of humic, fulvic, and total humic acids increased linearly (p<0.01 as the WL increased in the drinking water. The feed conversion (p<0.01 and the ileal digestibility of energy, the excretion of dry matter and energy, the retention of dry matter, ash and nitrogen and the AMEn showed quadratic responses (p<0.05 relative to the WL levels in drinking water. In Exp. 2, the increasing level of WL in the drinking water had quadratic effects on the final body weight, daily weight gain and feed conversion ratio (p<0.05. The addition of WL as a source of HS in the drinking water had beneficial effects on the growth performance, ileal digestibility of energy, the retention of nutrients as well on the AMEn in broiler chickens; the best results were observed when the WL was mixed at levels of 20% to 30% in the drinking water.

  7. Effects of dietary humic substances on egg production and egg shell ...

    African Journals Online (AJOL)

    Ninety Isa Brown layers from 51 to 61 weeks of age were allocated to three treatment groups, namely H0, H1 and H2. Control (H0) hens were fed a commercial diet while H1 and H2 hens were fed a diet including 30 and 90 ppm dietary humic acid in liquid form, respectively. Hens were placed individually in cages in three ...

  8. Humic substances elemental composition of selected taiga and tundra soils from Russian European North-East

    OpenAIRE

    Lodygin Evgeny; Beznosikov Vasily; Abakumov Evgeny

    2017-01-01

    Soils of Russian European North were investigated in terms of stability and quality of organic matter as well as in terms of soils organic matter elemental composi­tion. Therefore, soil humic acids (HAs), extracted from soils of different natural zones of Russian North-East were studied to characterize the degree of soil organic matter stabilization along a zonal gradient. HAs were extracted from soil of different zonal environments of the Komi Republic: south, middle and north taiga as well ...

  9. Applicability and Reliability of Gel-Filtration to Study Aquatic Humic Substances Revisited - the Effects of Ph on Molecular-Size Distributions

    NARCIS (Netherlands)

    Shaw, P.J.; De Haan, H.; Jones, R.I.

    1994-01-01

    The effect of pH on the molecular size distribution of dissolved humic substances (DHS) in surface waters from four different lakes in northern Europe was studied using Sephadex G‐100 gel filtration chromatography (GFC). New methods for the analysis of the elution profiles obtained are introduced,

  10. The effects of humic substances on the transport of radionuclides: Recent improvements in the prediction of behaviour and the understanding of mechanisms

    NARCIS (Netherlands)

    Bryan, N.D.; Abrahamsen, L.; Evans, N.; Warwick, P.; Buckau, G.; Weng, L.P.

    2012-01-01

    Some recent developments made during the European Union 6th Framework Integrated Project FUNMIG in the understanding and prediction of behaviour in ternary systems of radionuclides, humic substances and mineral surfaces are described. These developments are placed in the context of the existing

  11. The nematode Caenorhabditis elegans, stress and aging: Identifying the complex interplay of genetic pathways following the treatment with humic substances

    Directory of Open Access Journals (Sweden)

    Ralph eMenzel

    2012-04-01

    Full Text Available Low concentrations of the dissolved leonardite humic acid HuminFeed® (HF prolonged the lifespan and enhanced the thermal stress resistance of the model organism Caenorhabditis elegans. However, growth was impaired and reproduction delayed, effects which have also been identified in response to other polyphenolic monomers, including Tannic acid, Rosmarinic acid, and Caffeic acid. Moreover, a chemical modification of HF, which increases its phenolic/quinonoid moieties, magnified the biological impact on C. elegans. To gain a deep insight into the molecular basis of these effects, we performed global transcriptomics on young adult (3 d and old adult (11 d nematodes exposed to two different concentrations of HF. We also studied several C. elegans mutant strains in respect to HF derived longevity and compared all results with data obtained for the chemically modified HF. The gene expression pattern of young HF treated nematodes displayed a significant overlap to other conditions known to provoke longevity, including various plant polyphenol monomers. Besides the regulation of parts of the metabolism, TGF- signaling and Insulin-like signaling, lysosomal activities seem to contribute most to HF’s and modified HF’s lifespan prolonging action. These results support the notion that the phenolic/quinonoid moieties of humic substances are major building blocks that drive the physiological effects observed in C. elegans.

  12. Effects of humic substances derived from organic waste enhancement on the growth and mineral nutrition of maize.

    Science.gov (United States)

    Eyheraguibel, B; Silvestre, J; Morard, P

    2008-07-01

    A physico-chemical process has been developed to transform and enhance lignocellulosic waste in liquid humic extracts: humic-like substances (HLS). The aim of this study was to determine the effects of HLS on plant physiology in order to consider their agricultural use as organic fertilizers. The effects of HLS were evaluated on maize seed germination, and their impact on growth, development and mineral nutrition was studied on maize plants cultivated under hydroponic conditions. The experimental results showed that HLS do not increase the percentage and rate of germination but enhance the root elongation of seeds thus treated. Positive effects were also observed on the whole plant growth as well as on root, shoot and leaf biomass. These effects can be related to the high water and mineral consumption of plants undergoing this treatment. The high water efficiency indicated that such plants produce more biomass than non-treated plants for the same consumption of the nutrient solution. Furthermore, the use of HLS induced a flowering precocity and modified root development suggesting a possible interaction of HLS with developmental processes. Considering the beneficial effect of HLS on different stages of plant growth, their use may present various scientific and economic advantages. The physico-chemical transformation of sawdust is an interesting way of enhancing organic waste materials.

  13. Capacity of humic substances to complex with iron at different salinities in the Yangtze River estuary and East China Sea.

    Science.gov (United States)

    Yang, Rujun; Su, Han; Qu, Shenglu; Wang, Xuchen

    2017-05-03

    The iron binding capacities (IBC) of fulvic acid (FA) and humic acid (HA) were determined in the salinity range from 5 to 40. The results indicated that IBC decreased while salinity increased. In addition, dissolved iron (dFe), FA and HA were also determined along the Yangtze River estuary's increasing salinity gradient from 0.14 to 33. The loss rates of dFe, FA and HA in the Yangtze River estuary were up to 96%, 74%, and 67%, respectively. The decreases in dFe, FA and HA, as well as the change in IBC of humic substances (HS) along the salinity gradient in the Yangtze River estuary were all well described by a first-order exponential attenuation model: y(dFe/FA/HA, S) = a0 × exp(kS) + y0. These results indicate that flocculation of FA and HA along the salinity gradient resulted in removal of dFe. Furthermore, the exponential attenuation model described in this paper can be applied in the major estuaries of the world where most of the removal of dFe and HS occurs where freshwater and seawater mix.

  14. Chemical characterization of fractions of dissolved humic substances from a marginal sea—a case from the Southern Yellow Sea

    Science.gov (United States)

    Zhang, Yaoling; Yang, Keli; Du, Jinzhou; Zhang, Fenfen; Dong, Yaping; Li, Wu

    2017-03-01

    Marine dissolved organic matter (DOM) is one of the largest dynamic pools of organic carbon in the global carbon cycle, yet DOM is still chemically poorly characterized. To better understand the origin, composition, and cycling of DOM in the China marginal sea, dissolved humic substances (DHS) were isolated from seawaters in two locations in the Southern Yellow Sea. The DHS were subdivided into fulvic acids (FAs), humic acids (HAs) and the XAD-4 fractions. Complementary analytical approaches were used to characterize the isolated DHS samples including stable carbon isotopic composition, Fourier transform infrared spectroscopy (FTIR), 13C cross polarization magic angle spinning (CP/MAS) nuclear magnetic resonance (NMR), and pyrolysis gas chromatography-mass spectrometry (Py-GC/MS). The results demonstrated that both DHS samples encountered the influences from marine source, indicating that algal and microbial-derived materials are the predominant precursors for the studied samples. The three fractions of DHS showed different properties. FAs presented more aromatic features, whereas HAs contained more aliphatic lipids and proteinaceous materials. The XAD-4 fractions were enriched in 13C and contained more carbohydrates but less aromatic compounds. The lower molecular weight and higher heteroatom content and number of carboxyl groups for the XAD-4 fractions may give them considerable geochemical significance for aspects of trace metal species, bioavailability of pollutants, mineral weathering and water acidification in marine environments.

  15. Characterization of the humic substances isolated from postfire soils of scotch pine forest in Togljatty city, Samara region by the 13C-NMR spectroscopy

    Science.gov (United States)

    Maksimova, Ekaterina; Abakumov, Evgeny

    2016-04-01

    Postpyrogenic soil dynamics is an informative tool for studying of soil elementary processes in extreme temperature conditions and for predicting of short time environmental changes in conditions of catastrophic landscape changes. Soil organic matter (SOM) system evolution is the most rapid process of postpyrogenic soil development. In this relation the evaluation of humus accumulation rates and humification trend were conducted with use of the classical chemical and modern spectroscopy methods. Soil restoration after spontaneous forest fires near Togljatty city (Samara region, Russia) was abandoned in 2010, and further monitoring over the next four years was organized to evaluate the speed of biogenic processes and humus accumulation dynamics. Three key soil plots were studied for estimating SOM quality changes under the forest fire effect: surface forest fire, crown forest fire and control. Total carbon and nitrogen content as well as Cha/Cfa ratios (content of humic acids/ content of fulvic acids), were estimated to assess the dynamics of soil restoration. Humic acid powders were extracted and analyzed by elemental composition and 13C-NMR spectroscopy to assess changes in humic substance structure and composition. The data obtained indicate that burning of a forest floor and sod (humic) horizon led to humus losses and decreases in total carbon stocks. As a result of the fires, the content of humic acids in the pyrogenic horizon increased, leading alterations of humus type. Greater increases in the degree of organic matter humification were observed for surface fires than crown fires. It was shown that the humus molecular composition was substantially affected by the wildfires. The data show an increase in aromaticity, a loss of oxygen-containing groups and dehydrogenation of humic acids. Humic acids in the soils of the control plots and after wildfires were significantly different, especially in the ratios of hydrogen, oxygen and carbon. The increase in the

  16. Treatment and reuse of textile wastewaters by mild solar photo-Fenton in the presence of humic-like substances.

    Science.gov (United States)

    Negueroles, P G; Bou-Belda, E; Santos-Juanes, L; Amat, A M; Arques, A; Vercher, R F; Monllor, P; Vicente, R

    2017-05-01

    In this paper, the possibility of reusing textile effluents for new dyeing baths has been investigated. For this purpose, different trichromies using Direct Red 80, Direct Blue 106, and Direct Yellow 98 on cotton have been used. Effluents have been treated by means of a photo-Fenton process at pH 5. Addition of humic-like substances isolated form urban wastes is necessary in order to prevent iron deactivation because of the formation of non-active iron hydroxides. Laboratory-scale experiments carried out with synthetic effluents show that comparable results were obtained when using as solvent water treated by photo-Fenton with SBO and fresh deionized water. Experiments were scaled up to pilot plant illuminated under sunlight, using in this case a real textile effluent. Decoloration of the effluent could be achieved after moderate irradiation and cotton dyed with this water presented similar characteristics as when deionized water was used.

  17. Development of an innovative peat lipstick based on the UV-B protective effect of humic substances

    Directory of Open Access Journals (Sweden)

    R. Klöcking

    2013-04-01

    Full Text Available Humic acids (HA are known for their antiviral and UV-B protecting effects, and are considered promising as ingredients for a UV-protective lipstick which is being developed to minimise or even prevent recurrences of UV- induced herpes. In this study, the UV/Vis spectra of three natural HA and three synthetic HA-like substances are analysed to determine the appropriateness of their UV-absorbing characteristics for the product under development. The contribution of a matrix component (castor oil to the total UV absorption of the lipstick is also assessed. The results confirm the expected high UV-B absorption of the individual test substances, but reveal considerable differences in the UV-A wavelength range. Castor oil absorbs only UV-B radiation; and when mixed with HA it enhances total absorption in the UV-B range, but reduces it in the UV-A range. This is probably due to molecular interactions between castor oil and HA. Preliminary results from cultures of human U937 cells assayed for survival 24 hours after exposure to UV-B radiation show that both HA and castor oil exert a significant concentration-dependent UV-B protective filter effect similar to that of the UV-B absorbing reference substance p-aminobenzoic acid (PABA.

  18. Heavy metal sequestration by humic substances during phyto-treatment of sewage sludges

    Energy Technology Data Exchange (ETDEWEB)

    Peruzzi, E.; Doni, S.; Macci, C.; Ceccanti, B.; Masciandaro, G.

    2009-07-01

    The presence of heavy metals in sludges stabilized in a reed bed system, may affect their use for agricultural purposes; however, the environmental impact of sludges depends on the availability and phyto toxicity of their heavy metal. The aim of this paper was to determine the effectiveness of a reed bed (Phragmites Australia) sludge treatment system in two urban wastewater treatment plants in Italy after two-year period of operation: by estimating the process of sludge stabilization, following conventional and non conventional parameters related with the evolution of organic matter quality (Water soluble Carbon, Dehydrogenase activity, Fulvic Acids, Humic Acids, Pyrolytic indices or organic matter Mineralization and Humification); by following the heavy metal speciation bioavailability in sludges. (Author)

  19. Characterization of typical aquatic humic substances in areas of sugarcane cultivation in Brazil using tetramethylammonium hydroxide thermochemolysis

    Energy Technology Data Exchange (ETDEWEB)

    Tadini, A.M.; Constantino, I.C. [Departamento de Química e Ciências Ambientais, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista “Júlio de Mesquita Filho”, R. Cristóvão Colombo 2265, 15054-000 São José do Rio Preto, SP (Brazil); Nuzzo, A.; Spaccini, R.; Piccolo, A. [Dipartimento Scienze del Suolo, della Pianta, e dell' Ambiente, Università di Napoli Federico II, Via Università 100, 80055 Portici (Italy); Moreira, A.B. [Departamento de Química e Ciências Ambientais, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista “Júlio de Mesquita Filho”, R. Cristóvão Colombo 2265, 15054-000 São José do Rio Preto, SP (Brazil); and others

    2015-06-15

    Aquatic humic substances (AHSs) differ from one environment to another depending on land use and occupation. In addition, the effects of planting sugarcane on AHSs are not well known. Thus, the aim of this study was to characterize AHSs extracted from a river in a typical region of sugarcane cultivation during dry and rainy seasons. The main characteristics of the AHSs were obtained using Fourier transformation infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy and off-line pyrolysis coupled with gas chromatography and mass spectrometry (off-line tetramethylammonium hydroxide (TMAH)-GC–MS-thermochemolysis). The FTIR and NMR results were used to infer that no distinctions occurred between the sampling periods. The samples were composed of aromatic groups that were potentially associated with the presence of residual vegetable materials (lignin). The results of the off-line TMAH-GC–MS-thermochemolysis indicated that the structures of the AHSs had uniform compositions that were rich in fatty acid methyl esters (FAMEs), polysaccharide derivatives, aliphatic biopolymers derived from plants, long hydrocarbon chains, branched alkyl groups and methylene carbons. Thus, the results showed that the AHSs obtained from the sugarcane cultivation area during the crop period mainly consisted of resistant aliphatic hydrocarbons, which are derivatives of lignin and FAMEs in compounds rich in humic acid. Therefore, we concluded that sugarcane cultivation produces changes in AHSs because greater amounts of lignin derivatives were observed during the dry season, corresponding to sugarcane cultivation. - Highlights: • AHSs differ from one environment to another depending on land use and occupation. • AHSs extracted from a river in a typical region of sugarcane cultivation. • AHSs from the sugarcane area are influenced by the soil use and occupation. • AHSs contain lignin derivatives, fatty acid methyl esters and others. • Lignin was observed with

  20. Compost and Crude Humic Substances Produced from Selected Wastes and Their Effects on Zea mays L. Nutrient Uptake and Growth

    Science.gov (United States)

    Palanivell, Perumal; Susilawati, Kasim; Ahmed, Osumanu Haruna; Majid, Nik Muhamad

    2013-01-01

    Production of agriculture and timber commodities leads generation of enormous quantity of wastes. Improper disposal of these agroindustrial wastes pollutes the environment. This problem could be reduced by adding value to them. Therefore, a study was carried out to analyse and compare the nutrients content of RS, RH, SD, and EFB of composts and crude humic substances; furthermore, their effect on growth, dry matter production, and nutrient uptake for Zea mays L., and selected soil chemical properties were evaluated. Standard procedures were used to analyze humic acids (HA), crude fulvic acids (CFA), crude humin (CH), soil, dry matter production and nutrient uptake. Sawdust and RS compost matured at 42 and 47 days, respectively, while RH and EFB composts were less matured at 49th day of composting. Rice straw compost had higher ash, N, P, CEC, HA, K, and Fe contents with lower organic matter, total organic carbon, and C/N and C/P ratios. The HA of sawdust compost showed higher carbon, carboxylic, K, and Ca contents compared to those of RS, RH, and EFB. Crude FA of RS compost showed highest pH, total K, Ca, Mg, and Na contents. Crude humin from RS compost had higher contents of ash, N, P, and CEC. Rice straw was superior in compost, CFA, and CH, while sawdust compost was superior in HA. Application of sawdust compost significantly increased maize plants' diameter, height, dry matter production, N, P, and cations uptake. It also reduced N, P, and K based chemical fertilizer use by 90%. Application of CH and the composts evaluated in this study could be used as an alternative for chemical fertilizers in maize cultivation. PMID:24319353

  1. Compost and Crude Humic Substances Produced from Selected Wastes and Their Effects on Zea mays L. Nutrient Uptake and Growth

    Directory of Open Access Journals (Sweden)

    Perumal Palanivell

    2013-01-01

    Full Text Available Production of agriculture and timber commodities leads generation of enormous quantity of wastes. Improper disposal of these agroindustrial wastes pollutes the environment. This problem could be reduced by adding value to them. Therefore, a study was carried out to analyse and compare the nutrients content of RS, RH, SD, and EFB of composts and crude humic substances; furthermore, their effect on growth, dry matter production, and nutrient uptake for Zea mays L., and selected soil chemical properties were evaluated. Standard procedures were used to analyze humic acids (HA, crude fulvic acids (CFA, crude humin (CH, soil, dry matter production and nutrient uptake. Sawdust and RS compost matured at 42 and 47 days, respectively, while RH and EFB composts were less matured at 49th day of composting. Rice straw compost had higher ash, N, P, CEC, HA, K, and Fe contents with lower organic matter, total organic carbon, and C/N and C/P ratios. The HA of sawdust compost showed higher carbon, carboxylic, K, and Ca contents compared to those of RS, RH, and EFB. Crude FA of RS compost showed highest pH, total K, Ca, Mg, and Na contents. Crude humin from RS compost had higher contents of ash, N, P, and CEC. Rice straw was superior in compost, CFA, and CH, while sawdust compost was superior in HA. Application of sawdust compost significantly increased maize plants’ diameter, height, dry matter production, N, P, and cations uptake. It also reduced N, P, and K based chemical fertilizer use by 90%. Application of CH and the composts evaluated in this study could be used as an alternative for chemical fertilizers in maize cultivation.

  2. Compost and crude humic substances produced from selected wastes and their effects on Zea mays L. nutrient uptake and growth.

    Science.gov (United States)

    Palanivell, Perumal; Susilawati, Kasim; Ahmed, Osumanu Haruna; Majid, Nik Muhamad

    2013-01-01

    Production of agriculture and timber commodities leads generation of enormous quantity of wastes. Improper disposal of these agroindustrial wastes pollutes the environment. This problem could be reduced by adding value to them. Therefore, a study was carried out to analyse and compare the nutrients content of RS, RH, SD, and EFB of composts and crude humic substances; furthermore, their effect on growth, dry matter production, and nutrient uptake for Zea mays L., and selected soil chemical properties were evaluated. Standard procedures were used to analyze humic acids (HA), crude fulvic acids (CFA), crude humin (CH), soil, dry matter production and nutrient uptake. Sawdust and RS compost matured at 42 and 47 days, respectively, while RH and EFB composts were less matured at 49th day of composting. Rice straw compost had higher ash, N, P, CEC, HA, K, and Fe contents with lower organic matter, total organic carbon, and C/N and C/P ratios. The HA of sawdust compost showed higher carbon, carboxylic, K, and Ca contents compared to those of RS, RH, and EFB. Crude FA of RS compost showed highest pH, total K, Ca, Mg, and Na contents. Crude humin from RS compost had higher contents of ash, N, P, and CEC. Rice straw was superior in compost, CFA, and CH, while sawdust compost was superior in HA. Application of sawdust compost significantly increased maize plants' diameter, height, dry matter production, N, P, and cations uptake. It also reduced N, P, and K based chemical fertilizer use by 90%. Application of CH and the composts evaluated in this study could be used as an alternative for chemical fertilizers in maize cultivation.

  3. The mechanisms of humic substances self-assembly with biological molecules: The case study of the prion protein.

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    Gabriele Giachin

    Full Text Available Humic substances (HS are the largest constituent of soil organic matter and are considered as a key component of the terrestrial ecosystem. HS may facilitate the transport of organic and inorganic molecules, as well as the sorption interactions with environmentally relevant proteins such as prions. Prions enter the environment through shedding from live hosts, facilitating a sustained incidence of animal prion diseases such as Chronic Wasting Disease and scrapie in cervid and ovine populations, respectively. Changes in prion structure upon environmental exposure may be significant as they can affect prion infectivity and disease pathology. Despite its relevance, the mechanisms of prion interaction with HS are still not completely understood. The goal of this work is to advance a structural-level picture of the encapsulation of recombinant, non-infectious, prion protein (PrP into different natural HS. We observed that PrP precipitation upon addition of HS is mainly driven by a mechanism of "salting-out" whereby PrP molecules are rapidly removed from the solution and aggregate in insoluble adducts with humic molecules. Importantly, this process does not alter the protein folding since insoluble PrP retains its α-helical content when in complex with HS. The observed ability of HS to promote PrP insolubilization without altering its secondary structure may have potential relevance in the context of "prion ecology". These results suggest that soil organic matter interacts with prions possibly without altering the protein structures. This may facilitate prions preservation from biotic and abiotic degradation leading to their accumulation in the environment.

  4. Unrefined humic substances as a potential low-cost amendment for the management of acidic groundwater contamination.

    Science.gov (United States)

    Gonzalez-Raymat, Hansell; Anagnostopoulos, Vasileios; Denham, Miles; Cai, Yong; Katsenovich, Yelena P

    2018-02-09

    The present study explores a novel application of Huma-K, a commercially available, unrefined humic substance, as a promising low-cost source of organic matter for in situ remediation of contaminated acidic groundwater plumes. This can be achieved by creating a humic-rich coating on the surface of minerals which can enhance the sorption of contaminants from groundwater. Huma-K was characterized by means of scanning electron microscopy equipped with energy dispersive spectroscopy, Fourier-transform infrared analysis, and potentiometric titrations. Batch experiments were performed to investigate the sorption-desorption behavior of Huma-K and to evaluate what conditions (pH, contact time, and initial Huma-K concentration) affect these processes upon injection into aquifer sediments. As evidenced by potentiometric titrations, Huma-K possesses functional groups that have an acidic nature, with pK values in the range of 4-6 (carboxylic) and 9-10 (phenolic). Sorption, homogeneous precipitation, and surface-induced precipitation seem to be favored in the presence of sediment at pH 4, where there is less deprotonation of acidic functional groups. As the pH is increased, functional groups become negatively charged, leading to electrostatic repulsion and dissolution of Huma-K from sediment. Kinetic experiments indicate that Huma-K sorption is a slow-rate process, most likely governed by film diffusion. The enhanced sorption of Huma-K in acidic conditions suggests that it may be used to create a subsurface treatment zone in acidic aquifers for the sequestration of contaminants such as uranium. The treatment zone will persist as long as the pH does not increase sufficiently to cause soil-bound Huma-K to be released, remobilizing aqueous contaminants. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Short-column anion-exchange chromatography for soil and peat humic substances profiling by step-wise gradient of high pH aqueous sodium ethylenediaminetetraacetate.

    Science.gov (United States)

    Hutta, Milan; Ráczová, Janka; Góra, Róbert; Pessl, Juraj

    2015-08-21

    Novel anion-exchange liquid chromatographic method with step gradient of aqueous EDTA(4-) based mobile phase elution has been developed to profile available Slovak soil humic substances and alkaline extracts of various soils. The method utilize short glass column (30mm×3mm) filled in with hydrolytically stable particles (60μm diameter) Separon HEMA-BIO 1000 having (diethylamino)ethyl functional groups. Step gradient was programmed by mixing mobile phase composed of aqueous solution of sodium EDTA (pH 12.0; 5mmolL(-1)) and mobile phase constituted of aqueous solution of sodium EDTA (pH 12.0, 500mmolL(-1)). The FLD of HSs was set to excitation wavelength 480nm and emission wavelength 530nm (λem). Separation mechanism was studied by use of selected aromatic acids related to humic acids with the aid of UV spectrophotometric detection at 280nm. The proposed method benefits from high ionic strength (I=5molL(-1)) of the end mobile phase buffer and provides high recovery of humic acids (98%). Accurate and reproducible profiling of studied humic substances, alkaline extracts of various types of soils enables straightforward characterization and differentiation of HSs in arable and forest soils. Selected model aromatic acids were used for separation mechanism elucidation. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Measuring and modeling the hygroscopic growth of two humic substances in mixed aerosol particles of atmospheric relevance

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    I. R. Zamora

    2013-09-01

    Full Text Available The hygroscopic growth of atmospheric particles affects atmospheric chemistry and Earth's climate. Water-soluble organic carbon (WSOC constitutes a significant fraction of the dry submicron mass of atmospheric aerosols, thus affecting their water uptake properties. Although the WSOC fraction is comprised of many compounds, a set of model substances can be used to describe its behavior. For this study, mixtures of Nordic aquatic fulvic acid reference (NAFA and Fluka humic acid (HA, with various combinations of inorganic salts (sodium chloride and ammonium sulfate and other representative organic compounds (levoglucosan and succinic acid, were studied. We measured the equilibrium water vapor pressure over bulk solutions of these mixtures as a function of temperature and solute concentration. New water activity (aw parameterizations and hygroscopic growth curves at 25 °C were calculated from these data for particles of equivalent composition. We examined the effect of temperature on the water activity and found a maximum variation of 9% in the 0–30 °C range, and 2% in the 20–30 °C range. Five two-component mixtures were studied to understand the effect of adding a humic substance (HS, such as NAFA and HA, to an inorganic salt or a saccharide. The deliquescence point at 25 °C for HS-inorganic mixtures did not change significantly from that of the pure inorganic species. However, the hygroscopic growth of HA / inorganic mixtures was lower than that exhibited by the pure salt, in proportion to the added mass of HA. The addition of NAFA to a highly soluble solute (ammonium sulfate, sodium chloride or levoglucosan in water had the same effect as the addition of HA to the inorganic species for most of the water activity range studied. Yet, the water uptake of these NAFA mixtures transitioned to match the growth of the pure salt or saccharide at high aw values. The remaining four mixtures were based on chemical composition data for different

  7. Polyphenolic compounds progress during olive mill wastewater sludge and poultry manure co-composting, and humic substances building (Southeastern Tunisia).

    Science.gov (United States)

    Rigane, Hafedh; Chtourou, Mohamed; Ben Mahmoud, Imen; Medhioub, Khaled; Ammar, Emna

    2015-01-01

    In Mediterranean areas, olive mill wastes pose a major environmental problem owing to their important production and their high polyphenolic compounds and organic acids concentrations. In this work, the evolution of polyphenolic compounds was studied during co-composting of olive mill wastewater sludge and poultry manure, based on qualitative (G-50 sephadex) and quantitative (Folin-Ciocalteu), as well as high pressure liquid chromatography analyses. Results showed a significant polyphenolic content decrease of 99% and a noticeable transformation of low to high molecular weight fraction during the compost maturation period. During this step, polyphenols disappearance suggested their assimilation by thermophilic bacteria as a carbon and energy source, and contributed to humic substances synthesis. Polyphenolic compounds, identified initially by high pressure liquid chromatography, disappeared by composting and only traces of caffeic, coumaric and ferulic acids were detected in the compost. In the soil, the produced compost application improved the chemical and physico-chemical soil properties, mainly fertilising elements such as calcium, magnesium, nitrogen, potassium and phosphorus. Consequently, a higher potato production was harvested in comparison with manure amendment. © The Author(s) 2014.

  8. Size-exclusion chromatography of large molecules from coal liquids, petroleum residues, soots, biomass tars and humic substances.

    Science.gov (United States)

    Herod, Alan A; Zhuo, Yuqun; Kandiyoti, Rafael

    2003-06-30

    Size-exclusion chromatography (SEC) using 1-methyl-2-pyrrolidinone (NMP) as eluent has been calibrated using various standard polymers and model compounds and applied to the analysis of extracts of coal, petroleum and kerogens, to petroleum vacuum residues, soots, biomass tars and humic substances. Three separate columns of different molecular mass (MM) ranges were used, with detection by UV absorption; an evaporative light scattering detector was used for samples with no UV absorption. Fractionation was useful to separate signal from the less abundant high-mass material, which was normally masked by the strong signal from the more abundant low-mass material in the absence of fractionation. Fractionation methods used to isolate high-mass materials before SEC analysis included planar chromatography, column chromatography and solvent solubility. The apparently large molecules were concentrated into the fractions not soluble in common solvents and were relatively immobile in planar chromatography. All samples and fractions contained some material excluded from the column porosity. Evidence from other techniques suggests that the excluded material is of different structures from that of the resolved material rather than consisting of aggregates of small molecules. We speculate that the excluded material may elute early because the structures of this material are three-dimensional rather than planar or near planar.

  9. Humic substances alleviate the aquatic toxicity of polyvinylpyrrolidone-coated silver nanoparticles to organisms of different trophic levels.

    Science.gov (United States)

    Wang, Zhuang; Quik, Joris T K; Song, Lan; Van Den Brandhof, Evert-Jan; Wouterse, Marja; Peijnenburg, Willie J G M

    2015-06-01

    The present study investigated how humic substances (HS) modify the aquatic toxicity of silver nanoparticles (AgNPs) as these particles agglomerate in water and interact with HS. An alga species (Raphidocelis subcapitata), a cladoceran species (Chydorus sphaericus), and a freshwater fish larva (Danio rerio), representing organisms of different trophic levels, were exposed to colloids of the polyvinylpyrrolidone-coated AgNPs in the presence and absence of HS. Results show that the presence of HS alleviated the aquatic toxicity of the AgNP colloids to all the organisms in a dose-dependent manner. The particle size distribution of the AgNPs' colloidal particles shifted to lower values due to the presence of HS, implying that the decrease in the toxicity of the AgNP colloids cannot be explained by the variation of agglomeration size. The surface charge of the AgNPs was found to be more negative in the presence of high concentrations of HS, suggesting an electrostatic barrier by which HS might limit interactions between particles and algae cells; indeed, this effect reduced the algae toxicity. Observations on silver ions (Ag(+)) release show that HS inhibit AgNP dissolution, depending on the concentrations of HS. When toxic effects were expressed as a function of each Ag-species, toxicity of the free Ag(+) was found to be much higher than that of the agglomerated particles. © 2015 SETAC.

  10. Colloid facilitated transport of humic substances in soil: laboratory experiment and modeling calculation.

    Science.gov (United States)

    Dinu, Marina; Moiseenko, Tatyana

    2016-04-01

    An understanding of ability to predict the fate and transport of colloids in soil systems are of great importance in many environmental and industrial applications. Especially, in the case study sizes and zeta potentials of lignin and humus components (as a parameter reflecting the mobility and tread of organic substances). The objects of investigation were water extracts of gleepodzolic soil of European territory of Russia and Western Siberia, as well as humus substances extracted from this soil. In this study, evaluation of size, molecular weight distribution and zeta potential were used to predict the mobility of the organic component fractions of the soil. Fractionation was performed using multistage filtration plant (100 Da) and measuring physic-chemical parameters measured with the Malvern Zetasizer Nano ZSP. Significant differences in the distribution of organic matter on the molecular weight, charge (sign) of the zeta potential and the size of the sample of European Russia in comparison with samples of Western Siberia have been found. Also, laboratory studies have demonstrated of any differences in physicochemical parameters as infrared spectra, ultraviolet spectra, complexing ability of samples of the same soil type but different areas of Russia. The results can be used in the prediction of the migration ability of fractions humus substances and their stability at change physic-chemical conditions (the coefficient of mobility of the organic components by calculated in MathCad). This work was supported by the grant № 14-17-00460 RSF from 07.11.2014

  11. Effects of Americium-241 and humic substances on Photobacterium phosphoreum: bioluminescence and diffuse reflectance FTIR spectroscopic studies.

    Science.gov (United States)

    Kamnev, Alexander A; Tugarova, Anna V; Selivanova, Maria A; Tarantilis, Petros A; Polissiou, Moschos G; Kudryasheva, Nadezhda S

    2013-01-01

    The integral bioluminescence (BL) intensity of live Photobacterium phosphoreum cells (strain 1883 IBSO), sampled at the stationary growth stage (20 h), was monitored for further 300 h in the absence (control) and presence of (241)Am (an α-emitting radionuclide of a high specific activity) in the growth medium. The activity concentration of (241)Am was 2 kBq l(-1); [(241)Am]=6.5×10(-11) M. Parallel experiments were also performed with water-soluble humic substances (HS, 2.5 mg l(-1); containing over 70% potassium humate) added to the culture medium as a possible detoxifying agent. The BL spectra of all the bacterial samples were very similar (λ(max)=481±3 nm; FWHM=83±3 nm) showing that (241)Am (also with HS) influenced the bacterial BL system at stages prior to the formation of electronically excited states. The HS added per se virtually did not influence the integral BL intensity. In the presence of (241)Am, BL was initially activated but inhibited after 180 h, while the system (241)Am+HS showed an effective activation of BL up to 300 h which slowly decreased with time. Diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, applied to dry cell biomass sampled at the stationary growth phase, was used to control possible metabolic responses of the bacteria to the α-radioactivity stress (observed earlier for other bacteria under other stresses). The DRIFT spectra were all very similar showing a low content of intracellular poly-3-hydroxybutyrate (at the level of a few percent of dry biomass) and no or negligible spectroscopic changes in the presence of (241)Am and/or HS. This assumes the α-radioactivity effect to be transmitted by live cells mainly to the bacterial BL enzyme system, with negligible structural or compositional changes in cellular macrocomponents at the stationary growth phase. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Performance, meat quality, meat mineral contents and caecal microbial population responses to humic substances administered in drinking water in broilers.

    Science.gov (United States)

    Ozturk, E; Coskun, I; Ocak, N; Erener, G; Dervisoglu, M; Turhan, S

    2014-01-01

    This study was conducted to examine the effect of different levels of humic substances (HS) administered in drinking water on caecal microflora and mineral composition and colour characteristics of breast and thigh meats and the growth performance, carcass and gastrointestinal tract (GIT) traits of broiler chicks. A total of 480 3-d-old broiler chickens were randomly allocated to 4 treatments with 4 cages per treatment and 30 bird (15 males and 15 females) chicks per cage. All birds were fed on commercial basal diet. The control birds (HS0) received drinking water with no additions, whereas birds in the other treatment groups received a drinking water with 7.5 (HS7.5), 15.0 (HS15.0) and 22.5 (HS22.5) g/kg HS. Mush feed were provided on an ad libitum basis. Body weight and feed intake of broilers were determined at d 0, 21, and 42, and feed conversion ratio was calculated. On d 42, 4 broilers (2 males and 2 females) from each cage were slaughtered and the breast and thigh meats were collected for mineral composition and quality measurements. Performance, carcass and GIT traits and caecal microbial population of broiler chicks at d 42 were not affected by the dietary treatments. The lightness (L*) of breast and thigh meat decreased in broilers supplemented with 15 and 22.5 g/kg HS in drinking water. Although the redness (a*) of breast meat increased, yellowness of thigh meat decreased in broilers supplemented with 15 and 22.5 g/kg HS in drinking water (P meat quality without changing caecal microflora.

  13. Effects of americium-241 and humic substances on Photobacterium phosphoreum: Bioluminescence and diffuse reflectance FTIR spectroscopic studies

    Science.gov (United States)

    Kamnev, Alexander A.; Tugarova, Anna V.; Selivanova, Maria A.; Tarantilis, Petros A.; Polissiou, Moschos G.; Kudryasheva, Nadezhda S.

    The integral bioluminescence (BL) intensity of live Photobacterium phosphoreum cells (strain 1883 IBSO), sampled at the stationary growth stage (20 h), was monitored for further 300 h in the absence (control) and presence of 241Am (an α-emitting radionuclide of a high specific activity) in the growth medium. The activity concentration of 241Am was 2 kBq l-1; [241Am] = 6.5 × 10-11 M. Parallel experiments were also performed with water-soluble humic substances (HS, 2.5 mg l-1; containing over 70% potassium humate) added to the culture medium as a possible detoxifying agent. The BL spectra of all the bacterial samples were very similar (λmax = 481 ± 3 nm; FWHM = 83 ± 3 nm) showing that 241Am (also with HS) influenced the bacterial BL system at stages prior to the formation of electronically excited states. The HS added per se virtually did not influence the integral BL intensity. In the presence of 241Am, BL was initially activated but inhibited after 180 h, while the system 241Am + HS showed an effective activation of BL up to 300 h which slowly decreased with time. Diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, applied to dry cell biomass sampled at the stationary growth phase, was used to control possible metabolic responses of the bacteria to the α-radioactivity stress (observed earlier for other bacteria under other stresses). The DRIFT spectra were all very similar showing a low content of intracellular poly-3-hydroxybutyrate (at the level of a few percent of dry biomass) and no or negligible spectroscopic changes in the presence of 241Am and/or HS. This assumes the α-radioactivity effect to be transmitted by live cells mainly to the bacterial BL enzyme system, with negligible structural or compositional changes in cellular macrocomponents at the stationary growth phase.

  14. Probing the pH dependent optical properties of aquatic, terrestrial and microbial humic substances by sodium borohydride reduction

    Science.gov (United States)

    Chemically reducing humic (HA) and fulvic acids (FA) provides insight into spectroscopically identifiable structural moieties generating the optical properties of HA/FA from aquatic, microbial and terrestrial sources. Sodium borohydride reduction provides targeted reduction of carbonyl groups. The...

  15. Influence of Plant Growth Regulators and Humic Substance on the Phytoremediation of Nickel in a Ni-Polluted Soil

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    Mahshid Shafigh

    2017-06-01

    Full Text Available Introduction: Plants can uptake, bioaccumulate and immobilize different metals in their tissues. Phytoremediation technique has been used to remove hazardous substances including heavy metals from the environment. Assisted phytoremediation is usually the process of applying a chemical additive to heavy metal contaminated soils to enhance the metal uptake by plants. The main objective of present study was to investigate the effectiveness of plant growth regulators (PGRs and a humic substance (HS on Ni phytoremediation by maize in a Ni-pollutrd calcareous soil. Materials and Methods: The experiment designed as a 5×3 factorial trial arranged in a completely randomized design with three replicates. Three kilograms of soil was placed in plastic pots and pots were watered with distilled water to field capacity and maintained at this moisture level throughout the experiment by watering the pots to a constant weight. The soils were polluted with 250 mg Ni Kg-1 as Ni-nitrate Ni (NO32. Six maize (Zea mays L. seeds were planted 2 cm deep in soil and thinned to three uniform stands 1 week after emergence. Treatments consisted of three levels of soil application of commercially humic substance, HS, (0, 3, and 6 mg kg as Humax 95-WSG containing about 80% humic acid, and about 15% fulvic acid and five levels of PGRs (0 or 10 µM GA3, IAA, BAP and SA. The HS was applied as split doses in three times at 15 day intervals along with irrigation water. The seedlings were exposed to aqueous solutions of HS 16 days after sowing for the first time. Prepared solutions of PGRs were sprayed three times at 15 day intervals from emergence. Seven weeks after planting, shoots were harvested and roots were separated from soil carefully, both parts were rinsed with distilled water and dried at 65°C for 72 h, weighed, ground, and dry meshed at 550°C. Root and shoot dry matter and Ni concentration and uptake and phytoremediation criteria were considered as plant responses

  16. The effect of the humic substances, garlic (Allium sativum L., wormwood (Artemisia absinthium and walnut (Juglans regia on carcass parameters of broiler chickens

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    Veronika Pistová

    2017-05-01

    Full Text Available In this study the effect of humic substances, garlic (Allium sativum L., wormwood (Artemisia absinthium and walnut (Juglans regia on carcass parameters of broiler chickens were studied. Broiler chickens Ross 308 (n=60 were divided into 3 groups (n=20. The chickens of the control group were fed with complete feed mixtures without any additives. Chickens in the first experimental group E1were fed a diet containing 1.5% of humic substances, 0.4% of garlic powder and 0.1% of wormwood. Chickens in the second experimental group E2 were fed a diet containing 1.5% of humic substances, 0.4% of garlic powder and 0.1% of walnut.  The carcass weight, weight of heart, liver, gizzard, carcass yield and EPEF were evaluated. The carcass weight was in both experimental groups higher, but no statistically significant (P>0.05 in compare with the control group (values in the order of the groups: 1246.93±172.61; 1352.16±139.89 and 1308.30±166.17 g±SD. In the first experimental group E1 were weight of heart (12.15±2.29 g±SD and weight of gizzard (41.58±7.44 g±SD significantly higher (P≤0.05 compared to the control group (9.99 ±1.82; 33.62±5.03 g±SD.

  17. The effect of the humic substances, garlic (Allium sativum L., wormwood (Artemisia absinthium and walnut (Juglans regia on growth parameters and mortality of broiler chickens

    Directory of Open Access Journals (Sweden)

    Veronika Pistová

    2017-11-01

    Full Text Available The aim of this experiment was to determine the influence of humic substances, garlic (Allium sativum L., wormwood (Artemisia absinthium and walnut (Juglans regia on growth performance and mortality of broiler chickens. A total of 60 Ross 308 broiler chickens were divided into 3 groups (n=20. The control group of chickens was fed with complete feed mixtures without any additives. Chickens in the first experimental group E1 were fed a diet containing 1.5% of humic substances, 0.4% of garlic powder and 0.1% of wormwood. Chickens in the second experimental group E2 were fed a diet containing 1.5% of humic substances, 0.4% of garlic powder and 0.1% of walnut. The body weight, feed intake, feed conversion and total mortality were recorded in 42 day of fattening. At the end of the experiment was average body weight significantly higher (P≤0.01 in the first experimental group compared to the control group (values in the order of the groups: 1801.04±166.25; 1928.26±226.37 and 1850.24 g±SD. The feed intake was in the control group 3.59 kg per chicken, in the first experimental group E1 3.58 kg per chicken and in the second experimental group E2 3.45 kg per chicken. Feed conversion was in control group 1.95 kg, in the first experimental group E1 1.87 kg and in the second experimental group E2 1.84 kg with no significant different (P≥0.05 compared to the control group. Total mortality in 42 day was positive affected in the second experimental group, but with no significant different (P≥0.05 compared to the control group.

  18. The influence of seasonalness on the structural characteristics of aquatic humic substances extracted from Negro River (Amazon State) waters: interactions with Hg(II)

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Luciana C. de; Rocha, Julio C. [Universidade Estadual Paulista (UNESP), Araraquara, SP (Brazil). Inst. de Quimica]. E-mail: jrocha@iq.unesp.br; Sargentini Junior, Ezio; Serudo, Ricardo L. [Instituto Nacional de Pesquisas da Amazonia (INPA), Manaus, AM, (Brazil); Rosa, Andre H. [Universidade Estadual Paulista (UNESP), Sorocaba, SP (Brazil). Dept. de Engenharia Ambiental; Simoes, Marcelo L.; Martin-Neto, Ladislau; Silva, Wilson T. L. da [EMBRAPA Instrumentacao Agropecuaria, Sao Carlos, SP (Brazil)

    2007-07-01

    In this work, humic substances were extracted from water samples collected monthly from the Negro River basin in the Amazon state (Brazil) to study their properties in the Amazonian environment and interactions with the mercury ion considering the influence of seasonalness in this formation. The C/H, C/N and C/O atomic ratio parameters, functional groups, concentration of semiquinone-type free radicals, pH, pluviometric and fluviometric indices, and mercury concentrations were interpreted using hierarchical cluster analysis (HCA) and principal component analysis (PCA). The statistical analyses showed that when the pluviometric index was greater and the fluviometric index was smaller, the degree of humification of aquatic substances was greater. The following decreasing order of the degree of humification of the AHS collected monthly was established: Nov/02 to Feb/03 > Mar/02 to May/02 > Jun/02 to Oct/02. The greatest concentrations of mercury were detected in more humidified samples. These results suggest that due to inter and/or intra-molecular rearrangements, the degree of humification of aquatic humic substances is related to its affinity for Hg(II) ions. (author)

  19. Partitioning of uranyl between ferrihydrite and humic substances at acidic and circum-neutral pH

    Science.gov (United States)

    Dublet, Gabrielle; Lezama Pacheco, Juan; Bargar, John R.; Fendorf, Scott; Kumar, Naresh; Lowry, Gregory V.; Brown, Gordon E.

    2017-10-01

    As part of a larger study of the reactivity and mobility of uranyl (U(VI)O22+) cations in subsurface environments containing natural organic matter (NOM) and hydrous ferric oxides, we have examined the effect of reference humic and fulvic substances on the sorption of uranyl on 2-line ferrihydrite (Fh), a common, naturally occurring nano-Fe(III)-hydroxide. Uranyl was reacted with Fh at pH 4.6 and 7.0 in the presence and absence of Elliott Soil Humic Acid (ESHA) (0-835 ppm) or Suwanee River Fulvic Acid (SRFA) (0-955 ppm). No evidence was found for reduction of uranyl by either form of NOM after 24 h of exposure. The following three size fractions were considered in this study: (1) ≥0.2 μm (Fh-NOM aggregates), (2) 0.02-0.2 μm (dispersed Fh nanoparticles and NOM macro-molecules), and (3) NOM concentrations in these three size fractions. Partitioning of uranyl between Fh and NOM was determined in size fraction (1) using X-ray absorption spectroscopy (XAS). Uranyl sorption on Fh-NOM aggregates was affected by the presence of NOM in different ways depending on pH and type of NOM (ESHA vs. SRFA). The presence of ESHA in the uranyl-Fh-NOM ternary system at pH 4.6 enhanced uranyl uptake more than the presence of SRFA. In contrast, neither form of NOM affected uranyl sorption at pH 7.0 over most of the NOM concentration range examined (0-500 ppm); at the highest NOM concentrations (500-955 ppm) uranyl uptake in the aggregates was slightly inhibited at pH 7.0, which is interpreted as being due to the dispersion of Fh aggregates. XAS at the U LIII-edge was used to characterize molecular-level changes in uranyl complexation as a result of sorption to the Fh-NOM aggregates. In the absence of NOM, uranyl formed dominantly inner-sphere, mononuclear, bidentate sorption complexes on Fh. However, when NOM concentration was increased at pH 4.6, the proportion of uranyl-Fh inner-sphere sorption complexes decreased relative to uranyl-ESHA or uranyl-SRFA complexes, which comprised up

  20. Effect of climate changes in the holocene on the distribution of humic substances in the profile of forest-tundra peat mounds

    Science.gov (United States)

    Vasilevich, R. S.; Beznosikov, V. A.

    2017-11-01

    The molecular composition of humic substances in permafrost peatlands of the forest-tundra zone in northeastern European Russia has been characterized for the first time on the basis of systematic studies. Changes in the molar x(H): x(C) ratio along the peat profiles have been revealed, which is due to the activation of cryogenic processes in the upper part of the seasonally thawing layer, the natural selection of condensed humic molecules, and the botanical composition and degree of degradation of peat, which reflect the climatic features of the area in the Holocene. Dry-peat soils of mounds are worse heated during the summer period because of the buffering effect of moss litter, which results in a lower degree of condensation of humic and fulvic acid molecules in the peat horizons down to the permafrost table. Transformation of quantitative and qualitative parameters of specific organic compounds occurs at the permafrost boundary of peatlands, which can serve as an indicator of recent climate changes in high latitudes.

  1. Solubility of Heavy Metals/Metalloid on Multi-Metal Contaminated Soil Samples from a Gold Ore Processing Area: Effects of Humic Substances

    Directory of Open Access Journals (Sweden)

    Cácio Luiz Boechat

    2016-01-01

    Full Text Available ABSTRACT Bioavailability of heavy metals at contaminated sites is largely controlled by the physicochemical properties of the environmental media such as dissolved organic matter, hydroxides and clay colloids, pH, soil cation exchange capacity and oxidation-reduction potential. The aim of this study was to investigate soil pH and heavy metal solubility effect by levels of humic and fulvic acids applied in soil samples with different levels of contamination by heavy metals. The soil samples used in this study were collected in a known metal-contaminated site. Humic acid (HA and fulvic acid (FA were purchased as a commercially available liquid material extracted from Leonardite. The experiment was carried out in a factorial scheme of 4 × (4 + 1, with four contaminated soil samples and four treatments, comprised of two levels of HA, two levels of FA and a control. The HA treatments increased the solubility of Cu, Zn, Ni, Cr, Cd, Pb, As and Ba from soils, while FA treatments decreased, thus raising or not their availability and mobility in soil. Humic acid concentration did not influence soil pH and FA decreased soil pH until 0.7 units. The initial heavy metal concentration in soil affects the magnitude of the processes involving humic substances. The lower releases of heavy metals by FA verified the importance of the complexation properties of organic compounds. These results appear to encourage the use of HA for increased plant-availability of heavy metals in remediation projects and the use of FA for decreased plant-availability of heavy metals at contaminated sites with a risk of introducing metals into the food chain.

  2. Variation of iron redox kinetics and its relation with molecular composition of standard humic substances at circumneutral pH.

    Directory of Open Access Journals (Sweden)

    Ying Ping Lee

    Full Text Available Oxidation and reduction kinetics of iron (Fe and proportion of steady-state Fe(II concentration relative to total dissolved Fe (steady-state Fe(II fraction were investigated in the presence of various types of standard humic substances (HS with particular emphasis on the photochemical and thermal reduction of Fe(III and oxidation of Fe(II by dissolved oxygen (O2 and hydrogen peroxide (H2O2 at circumneutral pH (pH 7-8. Rates of Fe(III reduction were spectrophotometrically determined by a ferrozine method under the simulated sunlight and dark conditions, whereas rates of Fe(II oxidation were examined in air-saturated solution using luminol chemiluminescence technique. The reduction and oxidation rate constants were determined to substantially vary depending on the type of HS. For example, the first-order rate constants varied by up to 10-fold for photochemical reduction and 7-fold for thermal reduction. The degree of variation in Fe(II oxidation was larger for the H2O2-mediated reaction compared to the O2-mediated reaction (e.g., 15- and 3-fold changes for the former and latter reactions, respectively, at pH 8. The steady-state Fe(II fraction under the simulated sunlight indicated that the Fe(II fraction varies by up to 12-fold. The correlation analysis indicated that variation of Fe(II oxidation is significantly associated with aliphatic content of HS, suggesting that Fe(II complexation by aliphatic components accelerates Fe(II oxidation. The reduction rate constant and steady-state Fe(II fractions in the presence of sunlight had relatively strong positive relations with free radical content of HS, possibly due to the reductive property of radical semiquinone in HS. Overall, the findings in this study indicated that the Fe reduction and oxidation kinetics and resultant Fe(II formation are substantially influenced by chemical properties of HS.

  3. Influence of the apparent molecular size of humic substances on the efficiency of coagulation using Fenton's reagent

    Directory of Open Access Journals (Sweden)

    MARCELO DE JULIO

    2013-06-01

    Full Text Available This work used Fenton's reagent as a coagulating agent in the treatment of water samples with high true colour caused by humic substances (HS extracted from peat. In addition, the effects of the apparent molecular size of HS on coagulation, flocculation and flotation were studied. To that end, four distinct water samples having the same true colour were prepared using HS with different molecular sizes, which were obtained by ultrafiltration fractioning. Through optimisation of coagulant dosage and coagulation pH, as well as posterior construction of coagulation diagrams for each water sample, it was verified that the sample prepared with the smallest apparent molecular size of HS was the most difficult to treat, requiring higher coagulant (Fenton's reagent dosages than samples prepared with larger HS molecular sizes. Furthermore, filtration experiments after dissolved air flotation (DAF were carried out in an attempt to simulate conventional treatment. The most representative results in filtered water were: apparent colour ≤ 3 HU; turbidity Este trabalho empregou o reagente de Fenton como agente coagulante no tratamento de águas contendo cor elevada causada pela introdução de substâncias húmicas extraídas de turfa. Além disto, foi estudado o efeito do tamanho molecular aparente das substâncias húmicas na eficiência da coagulação, floculação e flotação de águas; para isto foram preparadas quatro águas distintas apresentado a mesma cor verdadeira, mas com substâncias húmicas de diferentes tamanhos moleculares, obtidas por fracionamento por ultrafiltração. Por meio da otimização da dosagem de coagulante e respectivo pH de coagulação e posterior construção dos diagramas de coagulação para cada água de estudo, verificou-se que a água preparada com as substâncias húmicas de menor tamanho molecular aparente apresentou maior grau de dificuldade para tratamento, requerendo dosagens de coagulante (reagente de Fenton bem

  4. Immersion freezing of water and aqueous ammonium sulphate droplets initiated by Humic Like Substances as a function of water activity

    Science.gov (United States)

    Rigg, Y. J.; Alpert, P. A.; Knopf, D. A.

    2013-02-01

    Immersion freezing of water and aqueous (NH4)2SO4 droplets containing Leonardite (LEO) and Pahokee peat (PP) serving as surrogates for Humic Like Substances (HULIS) has been investigated. Organic aerosol containing HULIS are ubiquitous in the atmosphere, however, their potential for ice cloud formation is uncertain. Immersion freezing has been studied for temperatures as low as 215 K and solution water activity, aw, from 0.85-1.0. The freezing temperatures of water and aqueous solution droplets containing LEO and PP are 5-15 K warmer than homogeneous ice nucleation temperatures. Heterogeneous freezing temperatures can be represented by a horizontal shift of the ice melting curve as a function of solution aw, Δaw, by 0.2703 and 0.2466, respectively. Corresponding heterogeneous ice nucleation rate coefficients, Jhet, are (9.6 ± 2.5)×104 and (5.4 ± 1.4)×104 cm-2 s-1 for LEO and PP containing droplets, respectively, and remain constant along freezing curves characterized by Δaw. Consequently predictions of freezing temperatures and kinetics can be made without knowledge of the solute type when relative humidity and IN surface areas are known. The acquired ice nucleation data are applied to evaluate different approaches to fit and reproduce experimentally derived frozen fractions. In addition, we apply a basic formulation of classical nucleation theory (α(T)-model) to calculate contact angles and frozen fractions. Contact angles calculated for each ice nucleus as a function of temperature, α(T)-model, reproduce exactly experimentally derived frozen fractions without involving free fit parameters. However, assigning the IN a single contact angle for entire population (single-α model) is not suited to represent the frozen fractions. Application of α-PDF, active sites, and deterministic model approaches to measured frozen fractions yield similar good representations. Thus, from fitting frozen fractions only, the underlying ice nucleation mechanism and nature of

  5. Forms and lability of phosphorus in humic and fulvic acids

    Science.gov (United States)

    Humic substances are involved in many biological and ecological processes in soils and natural waters. Characterization of phosphorus (P) associated with humic substances may shed light on the function of humic substances in P cycling and nutrition. In this chapter, we review and discuss the forms a...

  6. Selected pioneering works on humus in soils and sediments during the 20th century: A retrospective look from the International Humic Substances Society view

    Science.gov (United States)

    Feller, Christian; Brossard, Michel; Chen, Yona; Landa, Edward R.; Trichet, Jean

    Organic matter in general, and humic substances (HS) in particular, are involved in many processes in soils, sediments, rocks and natural waters. These include rock weathering, plant nutrition, pH buffering, trace metal mobility and toxicity, bioavailability, degradation and transport of hydrophobic organic chemicals, formation of disinfection by-products during water treatment, heterotrophic production in blackwater ecosystems and, more generally, the global carbon cycle. Before the 1970s, natural organic matter of different ecosystem pools ( i.e., soils, sediments, and natural waters) was often studied in isolation, although many similarities exist between them. This is particularly so for HS. In this historical context, a need appeared at the international level for bringing together environmental chemists, soil scientists, hydrologists, and geologists who were interested in HS to provide a forum for the exchange of ideas, to standardize analytical procedures and agree on definitions of HS. The International Humic Substances Society (IHSS) was founded in Denver, Colorado (USA) in 1981 with several objectives among them “to bring together scientists in the coal, soil, and water sciences with interests in humic substances” (home page of the IHSS web site: http://ihss.gatech.edu/ihss2/index.html). This paper presents selected pioneering works on humus in soils and sediments during the 20th century with a special focus on the links between the studies of soil HS and the formation, during early diagenesis, of the precursors of kerogens. Temporal coverage includes key contributions preceding the founding of the IHSS, and a brief history of the organization is presented.

  7. 13C-NMR chemical shift databases as a quick tool to evaluate structural models of humic substances

    DEFF Research Database (Denmark)

    Nyrop Albers, Christian; Hansen, Poul Erik

    2010-01-01

    Models for humic and fulvic acids are discussed based on 13C liquid state NMR spectra combined with results from elemental analysis and titration studies. The analysis of NMR spectra is based on a full reconstruction of the NMR spectrum done with help of 13C-NMR data bases by adding up chemical...

  8. Humic Substances-dependent Aggregation and Transport of Cerium Oxide Nanoparticles in Porous Media at Different pHs and Ionic Strengths

    Science.gov (United States)

    Mu, L.; Jacobson, A. R.; Darnault, C. J. G.

    2015-12-01

    Cerium oxide nanoparticles (CeO2 NPs) are commonly used in several fields and industries, such as chemical and pharmaceutical, due to both their physical and chemical properties. For example, they are employed in the manufacturing of catalysts, as fuel additives, and as polishing agents. The release and exposure to CeO2 NPs can occur during their fabrication, application, and waste disposal, as well as through their life-cycle and accidents. Therefore, the assessment of the dynamic nature of CeO2 NPs stability and mobilty in the environment is of paramount importance to establish the environmental and public health risks associated with their inevitable release in the environment. Humic substances are a key element of soils and have been revealed to possibly affect the fate and transport of nanoparticles in soils. Consequently, our present research aims at investigating the influence that different pHs, monovalent and divalent cations, Suwannee River humic acid, and Suwanee River fulvic acid have on the aggregation, transport, and deposition of CeO2 NPs. Batch studies performed with different concentrations of humic and fulvic acids associated with a wide spectrum of pHs and ionic strengths were examined. Key variables from these batch studies were then examined to simulate experimental conditions commonly encountered in the soil-water system to conduct column transport experiments in order to establish the fate and transport of CeO2 NPs in saturated porous media, which is a critical phase in characterizing the behavior of CeO2 NPs in subsurface environmental systems.

  9. The role of humic substances in the anaerobic reductive dechlorination of 2,4-dichlorophenoxyacetic acid by Comamonas koreensis strain CY01

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yibo [College of Life Sciences, South China Normal University, Guangdong Key Lab of Biotechnology for Plant Development, Guangzhou, 510631 (China)] [Guangdong Institute of Eco-environment and Soil Sciences, Guangzhou, 510650 (China)] [College of Life Science and Chemistry, Tianshui Normal University, Tianshui, 741000 (China); Wu Chunyuan [Guangdong Institute of Eco-environment and Soil Sciences, Guangzhou, 510650 (China); Wang Xiaojing, E-mail: wangyb02@163.com [College of Life Sciences, South China Normal University, Guangdong Key Lab of Biotechnology for Plant Development, Guangzhou, 510631 (China); Zhou Shungui, E-mail: sgzhou@soil.gd.cn [Guangdong Institute of Eco-environment and Soil Sciences, Guangzhou, 510650 (China)

    2009-05-30

    The role of the humic model compound, anthraquinone-2,6-disulfonate (AQDS), in the anaerobic reductive dechlorination of 2,4-dichlorophenoxyacetic acid (2,4-D) by the Fe(III)- and humic substances (HS)-reducing bacterium, Comamonas koreensis strain CY01 was investigated. The results taken as a whole indicated that (i) strain CY01 could couple glucose oxidation to 2,4-D reductive dechlorination; (ii) reductive dechlorination of 2,4-D by strain CY01 was greatly stimulated by the addition of AQDS; (iii) the transfer of electrons from biogenic AH{sub 2}QDS to 2,4-D was an abiotic process which can take place in the absence of microorganisms; and (iv) AH{sub 2}QDS was reoxidized during the chemical reaction, AQDS can serve again as electron acceptor for microorganisms, thus acting as electron shuttles. All the results suggested that 2,4-D reductive dechlorination by CY01 strain was a biochemical process that oxidizes the electron donors and transfers the electron to the acceptors through redox mediator, AQDS. We proposed the possible mechanism for the HS dependent reduction of 2,4-D. Our results suggested that microbial reduction of HS and subsequent chemical reduction of organic pollutants represent an important path of electron flow in anoxic natural environments. This work is a necessary preliminary step for better understanding the biodegradation of 2,4-D in subsurface soil.

  10. Characteristics of humic and fulvic acids in Arabian Sea sediments

    Digital Repository Service at National Institute of Oceanography (India)

    Sardessai, S.

    Humic and fulvic acids isolated from some of the shelf, slope and offshore sediments of the Arabian Sea were studied. The molecular weight, functional groups, elemental composition and infrared spectra were examined. Humic substances, dominated...

  11. Off-line TMAH-GC/MS and NMR characterization of humic substances extracted from river sediments of northwestern São Paulo under different soil uses

    Energy Technology Data Exchange (ETDEWEB)

    Tadini, Amanda Maria, E-mail: amandatadini@hotmail.com [Departamento de Química e Ciências Ambientais, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista “Júlio de Mesquita Filho”, R. Cristóvão Colombo 2265, 15054-000 São José do Rio Preto, SP (Brazil); Pantano, Glaucia; Toffoli, Ana Lúcia de [Departamento de Química e Ciências Ambientais, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista “Júlio de Mesquita Filho”, R. Cristóvão Colombo 2265, 15054-000 São José do Rio Preto, SP (Brazil); Fontaine, Barbara; Spaccini, Riccardo; Piccolo, Alessandro [Centro Interdipartimentale di Ricerca sulla Risonanza Magnetica Nucleare (NMR) per L' ambiente, l' Agro-Alimentare ed i Nuovi Materiali, CERMANU, Università di Napoli Federico II, Via Università 100, 80055 Portici (Italy); and others

    2015-02-15

    Humic substances (HS) vary according to the physical and chemical factors present in the environment. Thus, the characterization of HS is very important because it improves the understanding of the groups that comprise the chemical structure. Sediment HS were extracted from four locations representative of sugar cane cultivation, pasture, urban area and the impoundment of the Água Vermelha Hydroelectric Power Plant. Characterization using nuclear magnetic resonance (NMR) allowed us to infer that the HS from an area predominantly characterized by sugar cane cultivation (41.9%) and a typical rural area (35.0%) showed the highest aromaticity percentage. Using the off-line TMAH-thermochemolysis-GC-MS, we inferred that the HS of a typical rural area had a structure rich in plant waxes, plant biopolyester and a large amount of fatty acid methyl ester, which are related to the large amount of humic acid in the structure. The HS samples from the sugar cane cultivation area and the impoundment receiving all of the pollution load from the Turvo/Grande Hydrographic Basin (Bacia Hidrográfica do Turvo/Grande—BHTG) contained contributions from compounds rich in lipids and fatty acid methyl esters, highlighting the presence of the breakdown of petroleum-derived hydrocarbons in the area receiving the entire pollution load. We conclude that the HS extracted from the sediments of the Preto, Turvo and Grande rivers showed well-defined characteristics that varied depending on soil use and occupation, especially the HS extracted from sediments sampled in areas typically planted with sugar cane and rural areas, whose structures contained more aromatic groups. - Highlights: • The characterization of HS allows the understanding of the chemical structure. • HS of sediment in areas planted with sugar cane and rural areas contained more aromatic groups. • Influence of soil use and occupation on the chemical structure of the HS.

  12. The influence of aquatic humic substances characteristics on the coagulation efficiency using ferric chloride; Influencia das caracteristicas das substancias humicas aquaticas na eficiencia da coagulacao com o cloreto ferrico

    Energy Technology Data Exchange (ETDEWEB)

    Sloboda, Eliane; Vieira, Eny Maria [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Inst. de Quimica], e-mail: elisloboda@hotmail.com; Dantas, Angela Di Bernardo; Bernardo, Luiz Di [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Escola de Engenharia. Dept. de Hidraulica e Saneamento

    2009-07-01

    The aim of this study was to verify the influence of the apparent molecular size of aquatic humic substances on the effectiveness of coagulation with ferric chloride. Coagulation-filtration tests using jar test and bench-scale sand filters were carried out on samples of water with true color of approximately 100 Hazen units, prepared with aquatic humic substances of different molecular sizes (F{sub 1}: < 0.45 {mu}m, F{sub 2}: 100 kDa - 0.45 {mu}m, F{sub 3}: 30 - 100 kDa and F{sub 4}{sup '} : < 30 kDa). For the water samples with lower apparent molecular size fractions, greater dosages of coagulant was needed to remove the color around 5.0 Hanzen units, mainly because these water samples contain higher concentrations of fulvic acids, which exhibited a larger number of negatively-charged groups. (author)

  13. Stimulation of Tetrabromobisphenol A Binding to Soil Humic Substances by Birnessite and the Chemical Structure of the Bound Residues.

    Science.gov (United States)

    Tong, Fei; Gu, Xueyuan; Gu, Cheng; Xie, Jinyu; Xie, Xianchuan; Jiang, Bingqi; Wang, Yongfeng; Ertunc, Tanya; Schäffer, Andreas; Ji, Rong

    2016-06-21

    Studies have shown the main fate of the flame retardant tetrabromobisphenol A (TBBPA) in soils is the formation of bound residues, and mechanisms on it are less-understood. This study investigated the effect of birnessite (δ-MnO2), a naturally occurring oxidant in soils, on the formation of bound residues. (14)C-labeled TBBPA was used to investigate the pH dependency of TBBPA bound-residue formation to two soil humic acids (HAs), Elliott soil HA and Steinkreuz soil HA, in the presence of δ-MnO2. The binding of TBBPA and its transformation products to both HAs was markedly increased (3- to 17-fold) at all pH values in the presence of δ-MnO2. More bound residues were formed with the more aromatic Elliott soil HA than with Steinkreuz soil HA. Gel-permeation chromatography revealed a uniform distribution of the bound residues within Steinkreuz soil HA and a nonuniform distribution within Elliott soil HA. (13)C NMR spectroscopy of (13)C-TBBPA residues bound to (13)C-depleted HA suggested that in the presence of δ-MnO2, binding occurred via ester and ether and other types of covalent bonds besides HA sequestration. The insights gained in this study contribute to an understanding of the formation of TBBPA bound residues facilitated by δ-MnO2.

  14. Evaluation of humic substances during co-composting of food waste, sawdust and Chinese medicinal herbal residues.

    Science.gov (United States)

    Zhou, Ying; Selvam, Ammaiyappan; Wong, Jonathan W C

    2014-09-01

    Humification during co-composting of food waste, sawdust and Chinese medicinal herbal residues (CMHRs) was investigated to reveal its correlation with compost maturity. Food waste, sawdust and CMHRs were mixed at 5:5:1 and 1:1:1 (dry weight basis) while food waste:sawdust at 1:1 (dry wt. basis) served as control. Lime at 2.25% was added to all the treatments to alleviate low pH, and composted for 56 days. Humic acid/fulvic acid (HA/FA) ratio increased to 0.5, 2.0 and 3.6 in the control and treatment at 5:5:1, and 1:1:1 mixing ratio, respectively at the end of composting. The decrease in aliphatic organics in HA demonstrated the degradation of the readily available organics, while an increase in aromatic functional groups indicated the maturity of compost. Disappearance of hemicellulose and weak intensity of lignin in the CMHRs treatments indicated that the lignin provided the nucleus for HA formation; and the CMHRs accelerated the compost maturity. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. 13C NMR and ESR Characterization of Humic Substances Isolated from Soils of Two Siberian Arctic Islands

    Directory of Open Access Journals (Sweden)

    E. Abakumov

    2015-01-01

    Full Text Available Humic acids (HAs and fulvic acids (FAs of two Polar soils were investigated by 13C NMR and ESR spectroscopies, investigating the degree of humification and the molecular structure. One soil, from Bolshoi Lyakhovsky Island, contains two humus horizons: modern and buried. The other soil, from Wrangel Island, had only one modern humus horizon. The HAs and FAs of the two soils investigated show essential differences. The HAs show fewer oxygen-containing groups in comparison with the FAs, whereas the degree of aromaticity is two or three times higher in the HAs. The 13C NMR data also show that HAs are very different from FAs in terms of their molecular composition and hydrophobicity. Humification in the Arctic is limited by the very low content of lignin-derived compounds, due to the restricted vascular flora. As a result, the HAs, isolated from Polar soils, are more similar to the corresponding FAs than to the typical HAs of temperate soils. This was confirmed by ESR data, which show similar levels of free radical concentration for HAs and FAs and are related to the low level of aromaticity of both materials investigated. Apparently, the humification process in the soils of Polar Arctic deserts is in an initial stage.

  16. Competitive adsorption of PPCP and humic substances by carbon nanotube membranes: Effects of coagulation and PPCP properties.

    Science.gov (United States)

    Wang, Yifei; Yang, Qing; Dong, Junqing; Huang, Haiou

    2017-11-16

    Natural organic matter (NOM) and pharmaceuticals and personal care products (PPCP) are known to compete for adsorption sites on carbon nanotubes (CNT), resulting in decreasing PPCP adsorption onto CNT. In this study, four types of PPCP, as such acetaminophen (AAP), caffeine (CAF), triclosan (TCS), and carbendazim (CBD) were used to investigate the effects of PPCP properties and NOM coagulation on the competitive adsorption of PPCP and NOM. Coagulation preferentially removed HS from a natural surface water, thereby increasing adsorption of AAP, CAF, TCS and CBD by 19%, 13%, 17% and 11%, respectively. Similar trends were obtained with synthetic natural waters, for which the adsorption of AAP, CAF, TCS, and CBD increased by 29%, 7%, 44% and 69%, respectively, as humic acid (HA) concentration decreased from 10mgL-1 to 0mgL-1. Furthermore, PPCP properties also affected their competition with NOM for adsorption by CNT membranes Because CAF existed in cationic form at pH ranging from 7 to 8.3, its adsorption was less affected by the presence/coagulation of NOM than AAP, CBD, and TCS. Based upon these findings, coagulation has the potential to be integrated with CNT adsorption for the removal of PPCP compounds during advanced drinking water treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Copper binding to soil fulvic and humic acids

    NARCIS (Netherlands)

    Xu, Jinling; Tan, Wenfeng; Xiong, Juan; Wang, Mingxia; Fang, Linchuan; Koopal, Luuk K.

    2016-01-01

    Binding of Cu(II) to soil fulvic acid (JGFA), soil humic acids (JGHA, JLHA), and lignite-based humic acid (PAHA) was investigated through NICA-Donnan modeling and conditional affinity spectrum (CAS). It is to extend the knowledge of copper binding by soil humic substances (HS) both in respect of

  18. Effects of Fe(III) and quality of humic substances on As(V) distribution in freshwater: Use of ultrafiltration and Kohonen neural network.

    Science.gov (United States)

    Gontijo, Erik S J; Watanabe, Cláudia H; Monteiro, Adnívia S C; da Silva, Gilmare A; Roeser, Hubert M P; Rosa, Andre H; Friese, Kurt

    2017-12-01

    Humic substances (HS) are ubiquitous organic compounds able to affect mobility and availability of arsenic (As) in aquatic systems. Although it is known that associations between HS and As occur mainly via iron (Fe)-cationic bridges, the behaviour and distribution of this metalloid in HS- and Fe-rich environments is still not fully understood. In this paper, the quality of HS from different rivers in Brazil and Germany and its influence on the behaviour of As(V) under different Fe(III) concentrations were investigated. HS were extracted from four different rivers (Cascatinha, Holtemme, Selke and Warme Bode), characterised and fractionated into different molecular weight sizes (10, 5 and 1 kDa). Complexation tests were performed using an ultrafiltration system and 1 kDa membranes. All data was analysed using the Kohonen neural network (SOM - Self organising maps). All samples, except Selke, exhibited similar results of free As (plants) as precursor material. Most of the As and Fe was distributed in the fractions of higher (>10 kDa) and lower (<1 kDa) size. HS quality is an important factor to take into account when studying the behaviour of As in HS-rich environments. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Contribution of Quinones and Ketones/Aldehydes to the Optical Properties of Humic Substances (HS) and Chromophoric Dissolved Organic Matter (CDOM).

    Science.gov (United States)

    Del Vecchio, Rossana; Schendorf, Tara Marie; Blough, Neil V

    2017-11-20

    The molecular basis of the optical properties of chromophoric dissolved organic matter (CDOM) and humic substances (HS) remains poorly understood and yet to be investigated adequately. This study evaluates the relative contributions of two broad classes of carbonyl-containing compounds, ketones/aldehydes versus quinones, to the absorption and emission properties of a representative suite of HS as well as a lignin sample. Selective reduction of quinones to hydroquinones by addition of small molar excesses of dithionite to these samples under anoxic conditions produced small or negligible changes in their optical properties; however, when measurable, these changes were largely reversible upon exposure to air, consistent with the reoxidation of hydroquinones to quinones. With one exception, estimates of quinone content based on dithionite consumption by the HS under anoxic conditions were in good agreement with past electrochemical measurements. In contrast, reduction of ketones/aldehydes to alcohols employing excess sodium borohydride produced pronounced and largely, but not completely, irreversible changes in the optical properties. The results demonstrate that (aromatic) ketones/aldehydes, as opposed to quinones, play a far more prominent role in the optical absorption and emission properties of these HS, consistent with these moieties acting as the primary acceptors in charge-transfer transitions within these samples. As a method, anoxic dithionite titrations may further allow additional insight into the content and impact of quinones/hydroquinones on the optical properties of HS and CDOM.

  20. Changes in optical properties caused by UV-irradiation of aquatic humic substances from the amazon river basin: seasonal variability evaluation.

    Science.gov (United States)

    Rodríguez-Zúñiga, Ursula Fabiola; Milori, Débora Marcondes Bastos Pereira; da Silva, Wilson Tadeu Lopes; Martin-Neto, Ladislau; Oliveira, Luciana Camargo; Rocha, Julio Cesar

    2008-03-15

    Aquatic humic substances (AHS) isolated from two characteristic seasons of the Negro river, winter and summer corresponding to floody and dry periods, were structurally characterized by 13C nuclear magnetic ressonance. Subsequently, AHS aqueous solutions were irradiated with a polychromatic lamp (290-475 nm) and monitored by its total organic carbon (TOC) content, ultraviolet-visible (UV-vis) absorbance, fluorescence, and Fourier transformed infrared spectroscopy (FTIR). As a result, a photobleaching up to 80% after irradiation of 48 h was observed. Conformational rearrangements and formation of low molecular complexity structures were formed during the irradiation, as deduced from the pH decrement and the fluorescence shifting to lower wavelengths. Additionally a significant mineralization with the formation of CO2, CO, and inorganic carbon compounds was registered, as assumed by TOC losses of up to 70%. The differences in photodegradation between samples expressed by photobleaching efficiency were enhanced in the summer sample and related to its elevated aromatic content. Aromatic structures are assumed to have high autosensitization capacity effects mediated by the free radical generation from quinone and phenolic moieties.

  1. Influence of humic substances on the removal of pentachlorophenol by a biomimetic catalytic system with a water-soluble iron(III)-porphyrin complex.

    Science.gov (United States)

    Fukushima, Masami; Sawada, Akira; Kawasaki, Mikio; Ichikawa, Hiroyasu; Morimoto, Kengo; Tatsumi, Kenji; Aoyama, Masakazu

    2003-03-01

    To investigate some basic aspects of soil remediation using biomimetic catalysts, the effects of humic substances (HSs) on the removal of xenobiotics, such as pentachlorophenol (PCP), were investigated. The use of a biomimetic catalytic system using tetra(p-sulfophenyl)porphine-iron(III) (Fe(III)-TPPS) and potassium monopersulfate (KHSO5) resulted in the disappearance of PCP, accompanied by dechlorination. In addition, this process was enhanced by the presence of several types of HSs. The degrees of enhancement (% delta(PCP)60) achieved by the presence of HSs from peat and compost soils were larger than those in the presence of other types of HSs (tropical peat, brown forest, and ando soils). In control experiments, no PCP disappearance and dechlorination were observed in the presence of only KHSO5, only Fe(III)-TPPS, or combinations of HSs and either KHSO5 or Fe(III)-TPPS. To better understand the role of added HS in enhancing or inhibiting PCP disappearance, correlations between the chemical parameters of the HSs and % delta(PCP)60 were investigated. The most effective HSs had lower carboxylic acid contents and lower degrees of unsaturation. The carboxylic acid content and degree of unsaturation increase with the extent of humification. Therefore, HSs of a lower degree of humification would be predicted to be more useful in enhancing the disappearance of PCP in an Fe(III)-TPPS/KHSO5 system.

  2. Fluorescence of aqueous solutions of commercial humic products

    Science.gov (United States)

    Gosteva, O. Yu.; Izosimov, A. A.; Patsaeva, S. V.; Yuzhakov, V. I.; Yakimenko, O. S.

    2012-01-01

    We have studied the spectral luminescence characteristics of aqueous solutions of humic products obtained from different raw material sources, and their behavior as the excitation wavelength increases from 270 nm to 355 nm. We have identified differences in the spectral properties of industrial humic products from coalified materials, lignin-containing organic waste, and humic products from plant raw material (peat, sapropel, vermicompost). We have shown that humic products from plant raw material have spectral properties closer to those for humic substances in natural water or soil than humic products from coalified materials.

  3. Determination of humic and fulvic acids in commercial solid and liquid humic products by alkaline extraction and gravimetric determination

    Science.gov (United States)

    Increased use of humic substances in agriculture has generated intense interest among producers, consumers, and regulators for an accurate and reliable method for quantification of humic (HA) and fulvic acids (FA) in raw ores and products. Here we present a thoroughly validated method, the Humic Pro...

  4. Critical analysis of the data on complexation of lanthanides and actinides by natural organic matter: particular case of humic substances; Analyse critique des donnees de complexation des lanthanides et actinides par la matiere organique naturelle: cas des substances humiques

    Energy Technology Data Exchange (ETDEWEB)

    Reiller, P.

    2010-07-01

    This document proposes a critical analysis of the models that describe the actinides and lanthanides complexation by natural organic matter in general and by humic substances in particular. In order to better delimit the particular properties of these substances the most influent physical and chemical properties on complexation are recalled as a preamble. Models as well as data that has been used are reviewed, compiled, and eventually compared to independent data in order to identify (i) their application domain, (ii) the possible simplifications which permit to obtain operational models, (iii) the conditions in which simplifications cannot be ascertained yet, and (iv) the data or fields of knowledge which are still too uncertain. A comparison between the different models is proposed in order to adapt parameters from one model to another minimising the experimental acquisitions, or at least to focus on missing data. Usually, data on the complexation of free ions M{sup z+} are reliable; as soon as hydrolysis, or competition with another ligand in general, in at stake data are much less reliable. Predictions from models are much more uncertain: formation of mixed complexes with hydroxide or carbonate anions is not univocal whatever the modelling strategy. Hints for transfer functions between models which are believed to be incompatible could be explored in order to justify necessary simplifications for using operational modelling. Influence on the solubility of oxides could be quantified, but it is difficult to clearly separate it from colloidal particles stabilisation. The account of the competition between cations by the models has also been tested. In view of the small number of available experimental data there still lie some uncertainties especially for the media that are close to neutrality and in the case of competition with magnesium, but overall in the case of the competition with aluminium and iron. The influence of redox activity of humic substances is

  5. Using UV-vis absorbance spectral parameters to characterize the fouling propensity of humic substances during ultrafiltration.

    Science.gov (United States)

    Zhou, Minghao; Meng, Fangang

    2015-12-15

    Ultrafiltration (UF) can achieve excellent removal of natural organic matter (NOM), but the main challenge for this process is the limited understanding of membrane fouling. The objective of this study is to explore the potential of UV-vis spectroscopic analysis for the detection of membrane fouling caused by humic acids (HA) at different solution chemistries (i.e., calcium ions (Ca(2+)) and pH). In the presence of Ca(2+), several spectral parameters, including the DSlope(325-375) (the slope of the log-transformed absorbance spectra over 325-375 nm), S(275-295) (the slope of the absorption coefficient over 257-295 nm) and S(R) (the ratio of S(275-295) to S(350-400)) of various HA solutions, were correlated with the molecule aggregation and the membrane fouling potential. Interestingly, increased DSlope(325-375) and decreased S(275-295) and S(R) were observed for the HA-Ca(2+) interaction under alkaline conditions (i.e., pH = 9) relative to those in lower pH environments (i.e., pH = 7 or 6), suggesting that spectral parameters were able to predict HA-Ca(2+) interactions under varying pH conditions. The strong correlations between the spectral parameters and the unified membrane fouling index (UMFI) obtained from UF experiments further corroborated that the spectral parameters were able to predict the membrane fouling potential. Moreover, the spectral parameters were also found to well reveal the fouling extent of the mixture of HA and Suwannee River NOM (SRNOM) or the pure SRNOM added with varying calcium concentrations, implying that the spectroscopic analysis was also available for the indication of practical NOM fouling. In addition, the measurement of S(275-295) and S(R) of the permeate solution suggests an increasing proportion of small-molecule HA in the permeate during the UF process. This study not only expands our knowledge of NOM-Ca(2+) aggregates as well as their role in membrane fouling behavior but also provides an approach for the in situ

  6. Qualidade textural de tomates cultivados em substratos orgânicos submetidos à aplicação de substâncias húmicas Textural quality of tomatoes grown in organic substrates subjected to application of humic substances

    Directory of Open Access Journals (Sweden)

    Caroline Roberta Freitas Pires

    2009-11-01

    Full Text Available O objetivo deste trabalho foi avaliar os efeitos de substâncias húmicas e de diferentes substratos orgânicos na qualidade textural dos frutos do tomateiro híbrido Vênus, em ambiente protegido. Utilizaram-se, quatro tipos de substratos: fibra de coco; fibra de coco e casca de café carbonizada 1/3 (v/v; fibra de coco e casca de café carbonizada 2/3 (v/v; e casca de café carbonizada. As doses de substâncias húmicas (ácido húmico, 10% + ácido fúlvico 10,2% utilizadas foram 0, 20, 40 e 80 L ha-1, aplicadas ao substrato quinzenalmente, a partir do oitavo dia após o transplantio. O delineamento utilizado foi o de blocos ao acaso, em arranjo fatorial 4x4. Avaliaram-se firmeza dos frutos, percentagem de solubilização péctica e atividade enzimática (pectinametilesterase e poligalacturonase. Observou-se variação na atividade das enzimas pectinametilesterase e poligalacturonase, em consequência das doses de substâncias húmicas adicionadas, nos diferentes substratos. O efeito das doses de substâncias húmicas sobre a firmeza, solubilidade de pectinas e atividade enzimática, em frutos de tomate, depende do substrato utilizado. Frutos obtidos de plantas cultivadas em fibra de coco apresentaram aumento de firmeza e redução da percentagem de solubilização péctica com a aplicação de doses crescentes de substâncias húmicas.The objective of this work was to evaluate the effects of humic substances and of different organic substrates on the textural quality of tomato fruit of the Vênus hybrid, in a protected environment. Four types of substrates were used: coconut fiber; coconut fiber and carbonized coffee husk 1/3 (v/v; coconut fiber and carbonized coffee husk 2/3 (v/v; and carbonized coffee husk. The humic substances (humic acid, 10% + fulvic acid, 10,2% dosages of 0, 20, 40 and 80 L ha-1 were applied onto the substrates fortnightly from the eighth day after transplanting. The experimental design was in randomized block in a 4x4

  7. The improvement of multi-contaminated sandy loam soil chemical and biological properties by the biochar, wood ash, and humic substances amendments.

    Science.gov (United States)

    Pukalchik, Maria; Mercl, Filip; Panova, Maria; Břendová, Kateřina; Terekhova, Vera A; Tlustoš, Pavel

    2017-10-01

    Nowadays trace metal contamination of soils represents an important environmental hazard. Nevertheless, the use of some secondary waste products as amendments may restore the common soil functions. This paper focuses on the chemical and biological influence of wood biochar (BC), wood ash (WA) and humic substances (HS), alone and in the mixtures, on a heavily multi-contaminated sandy loam soil. The soil was amended by above-mentioned materials to follow a pH-increasing design (pH Ca from 6.0 to 6.5, 7.0 and 7.5); soil samples were analyzed after 3, 30, and 60 days using a set of variables, namely the plant-available trace element concentrations (Cu, Cd, and Zn), microbial biomass carbon (Cmic), and microbial quotient (qCO 2 ), as well as toxicity to Sinapis alba and Daphnia magna. Wood ash and WA + HS were the most efficient treatments to decrease mobile Cd and Zn concentrations in the soil, while HS, BC, and BC + HS combinations were the most effective in reducing the Cu mobility. The effect of BC and WA on the Cmic and qCO 2 was mostly negative, whereas adding HS markedly increased Cmic and reduced qCO 2 in soil. After amendment applications, the root elongation of mustard was significantly increased in HS and combined treatments (BC + HS, WA + HS). Additionally, BC + HS, WA + HS and WA 8.4% significantly decreased the toxicity of leachates to D. magna to the low-, or non-toxic levels. Our results suggest that the combination of amendments with HS can be a suitable remediation strategy for heavily contaminated soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Synthesis of model humic substances: a mechanistic study using controllable H/D exchange and Fourier transform ion cyclotron resonance mass spectrometry.

    Science.gov (United States)

    Zherebker, Alexander Ya; Airapetyan, David; Konstantinov, Andrey I; Kostyukevich, Yury I; Kononikhin, Alexey S; Popov, Igor A; Zaitsev, Kirill V; Nikolaev, Eugene N; Perminova, Irina V

    2015-07-07

    The products of the oxidative coupling of phenols are frequently used as synthetic analogues to natural humic substances (HS) for biomedical research. However, their molecular compositions and exact structures remain largely unknown. The objective of this study was to develop a novel approach for the molecular-level analysis of phenolic polymerisates that is capable of inventorying molecular constituents and resolving their distinct structural formulas. For this purpose, we have synthesized the model HS using the oxidative coupling of a specifically designed phenylpropanoic monomer, 3-(4-hydroxy-3-methoxyphenyl)-3-oxopropionic acid, to hydroquinone. We have characterized the synthesized model HS using high resolution Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS), (1)H NMR spectroscopy, and controllable hydrogen/deuterium (H/D) exchange. We succeeded in the molecular inventory of the model HS. The assigned molecular formulas occupied the substantial space of CHO compositions in the Van Krevelen diagram with a maximum density found in the regions of tannins and lignins, resembling those of natural HS. To identify the exact structural formulas of the individual constituents in the model HS, we have applied selective H/D exchange of non-labile backbone protons by a choice of basic or acidic catalytic conditions followed by FTICR MS. The determined formulas allowed us to verify the proposed pathways of hydroxylation and carboxylation in the course of the phenolic coupling and to identify the acetylation of aromatic rings as an important side reaction. We conclude that the proposed analytical approach may be used to identify the molecular carriers of biological activity within the phenolic polymerisates and eventually within natural HS.

  9. Microscopic and spectroscopic characterization of humic substances from a compost amended copper contaminated soil: main features and their potential effects on Cu immobilization.

    Science.gov (United States)

    Medina, Jorge; Monreal, Carlos; Chabot, Denise; Meier, Sebastián; González, María Eugenia; Morales, Esteban; Parillo, Rita; Borie, Fernando; Cornejo, Pablo

    2017-06-01

    We characterized humic substances (HS) extracted from a Cu-contaminated soil without compost addition (C) or amended with a wheat straw-based compost (WSC) (H1), co-composted with Fe 2 O 3 (H2), or co-composted with an allophane-rich soil (H3). Extracted HS were characterized under electron microscopy (SEM/TEM), energy-dispersive X-ray (X-EDS), and Fourier transform infrared (FTIR) spectroscopy. In addition, HS extracted from WSC (H4) were characterized at pH 4.0 and 8.0 with descriptive purposes. At pH 4.0, globular structures of H4 were observed, some of them aggregating within a large network. Contrariwise, at pH 8.0, long tubular and disaggregated structures prevailed. TEM microscopy suggests organo-mineral interactions at scales of 1 to 200 nm with iron oxide nanoparticles. HS extracted from soil-compost incubations showed interactions at nanoscale with minerals and crystal compounds into the organic matrix of HS. Bands associated to acidic functional groups of HS may suggest potential sorption interactions with transition metals. We conclude that metal ions and pH have an important role controlling the morphology and configuration of HS from WSC. Characterization of H4 extracted from WSC showed that physicochemical protection of HS could be present in composting systems treated with inorganic materials. Finally, the humified fractions obtained from compost-amended soils may have an important effect on metal-retention, supporting their potential use in metal-contaminated soils.

  10. New insights on humic-like substances associated with wintertime urban aerosols from central and southern Europe: Size-resolved chemical characterization and optical properties

    Science.gov (United States)

    Voliotis, Aristeidis; Prokeš, Roman; Lammel, Gerhard; Samara, Constantini

    2017-10-01

    Although Humic-LIke Substances (HULIS) are important contributors to the mass of organic aerosol in airborne particulate matter (PM), little is known about their chemical composition, while, their size-resolved optical properties have not been studied yet. Here, HULIS fractions were isolated from size-resolved aerosol samples (≤0.49, 0.49-0.95, 0.95-3 and 3-10 μm) collected in urban and suburban environments of four European cities during wintertime. The bulk (i.e., sum of all size fractions) concentration of HULIS ranged between 1.29 and 2.80 μg m-3 across sites with highest values in the ≤0.49 μm particle size fraction. The contribution of the carbon mass of HULIS (HULIS-C) to the water-soluble organic carbon content (WSOC) of PM was 32-43%, which is typical for urban sites affected by biomass burning. The Mass Absorption Efficiency (MAE), which characterizes the efficiency of absorbing solar energy per carbon mass of HULIS decreased with particle size, suggesting that the finest size fractions contain more light-absorbing chromophores, which could affect the light-absorbing ability of organic aerosols. The good correlation of HULIS with effective biomass tracers such as K+, as well as with secondary inorganic aerosol components, proposed that HULIS had both primary (i.e., biomass burning) and secondary sources. The Fourier Transfer Infrared coupled to Attenuation Total Reflectance (FTIR-ATR) spectra demonstrated prevalence of aromatic over carboxylic functional groups in most HULIS fractions, indicating contribution from coal combustion emissions in addition to fresh biomass burning aerosol. The new findings add to better understanding the sources and chemical structure of HULIS in urban and suburban environments.

  11. The effect of different replications of humic acid fertilization on yield ...

    African Journals Online (AJOL)

    Jane

    2011-06-22

    Jun 22, 2011 ... metabolism are less understood, but it seems that humic substances may influence both respiration and photosynthesis (Nardi et al., 2002). Humic substances have a very strong influence on the growth of plant roots. When humic and fulvic acids are applied on the soil, enhancement of root initiation and.

  12. Effect of some heavy metals and soil humic substances on the phytochelatin production in wild plants from silver mine areas of Guanajuato, Mexico.

    Science.gov (United States)

    Figueroa, Julio Alberto Landero; Wrobel, Katarzyna; Afton, Scott; Caruso, Joseph A; Corona Felix Gutierrez, J; Wrobel, Kazimierz

    2008-02-01

    Phytochelatins (PCs) were determined in the wild plants, focusing on their relationship with the levels of heavy metals and humic substances (HS) in soil. Ricinus communis and Tithonia diversifolia were collected from several sites in Guanajuato city (Mexico), which had long been the silver and gold mining center. The analysis of PCs in root extracts was carried out by liquid chromatography (derivatization with monobromobimane). Total Ag, Cd, Cu and Pb in plant roots and in soil samples, as well as soil HS were determined. The association of metals with HS in soils was evaluated by size exclusion chromatography (SEC) with UV and ICP-MS detection. The results obtained revealed the induction of PCs in R. communis but not in T. diversifolia. The levels of Cd and Pb in plant roots presented strong positive correlation with PC-2 (r=0.9395, p=0.005; r=0.9573, p=0.003, respectively), indicating that these two metals promote PCs induction in R. communis. On the other hand, the inverse correlation was found between soil HS and metal levels in roots of R. communis (Cu>Pb>Cd>Ag), in agreement with the decreasing affinity of these metals to HS. Importantly, the inverse correlation between soil HS and plant PC-2 was observed (r=-0.7825, p=0.066). These results suggest that metals strongly bound to HS could be less bioavailable to plants, which in turn would limit their role in the induction of PCs. Indeed, the SEC elution profiles showed Pb but not Cd association with HS and the correlation between metal in soil and PC-2 in plant was statistically significant only for Cd (r=0.7857, p=0.064). Based on these results it is proposed that the role of heavy metals in PCs induction would depend on their uptake by R. communis, which apparently is controlled by the association of metals with soil HS. This work provides further evidence on the role of environmental conditions in the accumulation of heavy metals and phytochelatin production in plants.

  13. Studies of metal complexation with humic and fulvic acid

    Energy Technology Data Exchange (ETDEWEB)

    King, S.J.; Warwick, P. [Loughborough Univ. (United Kingdom). Dept. of Chemistry

    1998-08-01

    The main objective of the project is to determine the influence of humic substances on the migration of radionuclides. One of the first steps taken in order to deepen this understanding was to investigate the complexation of Eu{sup 3+} with humic substances (Task 2). There is concern that after disposal in underground repositories radionuclides may eventually come into contact with groundwaters containing humic acids at elevated temperatures. Preliminary investigations have therefore been undertaken to determine the effect of temperature on the stability constants for europium binding to humic acid by a series of batch experiments. Eu is used as an analogue of trivalent actinides. (orig.)

  14. Substâncias húmicas de turfa: estudo dos parâmetros que influenciam no processo de extração alcalina Humic substances of peat: study of the parameters that influence on the process of alkaline e extraction

    Directory of Open Access Journals (Sweden)

    André Henrique Rosa

    2000-08-01

    Full Text Available This study reports the parameters which influence on extraction of humic substances (HS from peat. The yield, organic and inorganic contend, E4/E6 ratio and elemental composition (C,H,N of the extracted HS have been determined. The functional groups were identified by Fourier-transform infrared espectroscopy. The results showed influence of the extractor type, concentration, time, temperature and granular texture of the sample in the extraction. This work contributes to better understanding of the extraction process showing the necessity of the standard method to extract humic substances from soil

  15. Woodward Seminars

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 7. Woodward Seminars. Subramania Ranganathan. Think It Over Volume 19 Issue 7 July 2014 pp 654-657. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/019/07/0654-0657. Keywords. Reaction ...

  16. Determination of dynamic metal complexes and their diffusion coefficients in the presence of different humic substances by combining two analytical techniques.

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, P.; Manek, A.; Niyogi, S.; Hudson, J.

    . These discrepancies were caused by diffusion controlled metal flux (towards the binding resin gel) in the diffusive gel of DGT. The interactions of Cu and Ni with humic acids are stronger than their interactions with fulvic acid and natural organic matter. Changes...

  17. Interactions between radionuclides and organic colloids. Structure and reactivity of humic compounds; Interactions entre radionucleides et colloides organiques. Structure et reactivite des substances humiques

    Energy Technology Data Exchange (ETDEWEB)

    Plancque, G

    2001-09-01

    Humic compounds are the main organic colloids present in natural waters. These compounds can significantly modify the speciation of metals and control their properties, like migration, toxicity or bio-availability. It is thus important to study their speciation in conditions representative to those encountered in the natural environment. The aim of this work is to analyze the reactivity of these humic compounds. Two spectroscopic techniques have been used: the time-resolution laser spectro-fluorimetry, limited to the study of fluorescent elements, and the electro-spray source mass spectroscopy which requires the development of specific protocols for all elements of the periodic classification system. Europium, a fluorescent element analogue to trivalent actinides, has been chosen as test-metal for the intercomparison of both spectroscopic techniques. The first technique has permitted to determine the inorganic and organic speciation (spectra and lifetime of europium hydroxides and carbonates, and constants of interaction with humic acids, respectively). The limitations of this technique in the study of inorganic speciation has been evidenced. Humic compounds have a badly defined structure. The use of high-resolution mass spectroscopy has permitted to propose in a direct and experimental way, a molecular structure of aquatic fulvic acids in agreement with their known physico-chemical properties. (J.S.)

  18. Comprehensive characterization of humic-like substances in smoke PM2.5 emitted from the combustion of biomass materials and fossil fuels

    Science.gov (United States)

    Fan, Xingjun; Wei, Siye; Zhu, Mengbo; Song, Jianzhong; Peng, Ping'an

    2016-10-01

    Humic-like substances (HULIS) in smoke fine particulate matter (PM2.5) emitted from the combustion of biomass materials (rice straw, corn straw, and pine branch) and fossil fuels (lignite coal and diesel fuel) were comprehensively studied in this work. The HULIS fractions were first isolated with a one-step solid-phase extraction method, and were then investigated with a series of analytical techniques: elemental analysis, total organic carbon analysis, UV-vis (ultraviolet-visible) spectroscopy, excitation-emission matrix (EEM) fluorescence spectroscopy, Fourier transform infrared spectroscopy, and 1H-nuclear magnetic resonance spectroscopy. The results show that HULIS account for 11.2-23.4 and 5.3 % of PM2.5 emitted from biomass burning (BB) and coal combustion, respectively. In addition, contributions of HULIS-C to total carbon and water-soluble carbon in smoke PM2.5 emitted from BB are 8.0-21.7 and 56.9-66.1 %, respectively. The corresponding contributions in smoke PM2.5 from coal combustion are 5.2 and 45.5 %, respectively. These results suggest that BB and coal combustion are both important sources of HULIS in atmospheric aerosols. However, HULIS in diesel soot only accounted for ˜ 0.8 % of the soot particles, suggesting that vehicular exhaust may not be a significant primary source of HULIS. Primary HULIS and atmospheric HULIS display many similar chemical characteristics, as indicated by the instrumental analytical characterization, while some distinct features were also apparent. A high spectral absorbance in the UV-vis spectra, a distinct band at λex/λem ≈ 280/350 nm in EEM spectra, lower H / C and O / C molar ratios, and a high content of [Ar-H] were observed for primary HULIS. These results suggest that primary HULIS contain more aromatic structures, and have a lower content of aliphatic and oxygen-containing groups than atmospheric HULIS. Among the four primary sources of HULIS, HULIS from BB had the highest O / C molar ratios (0.43-0.54) and [H

  19. Comprehensive characterization of humic-like substances in smoke PM2.5 emitted from the combustion of biomass materials and fossil fuels

    Directory of Open Access Journals (Sweden)

    X. Fan

    2016-10-01

    Full Text Available Humic-like substances (HULIS in smoke fine particulate matter (PM2.5 emitted from the combustion of biomass materials (rice straw, corn straw, and pine branch and fossil fuels (lignite coal and diesel fuel were comprehensively studied in this work. The HULIS fractions were first isolated with a one-step solid-phase extraction method, and were then investigated with a series of analytical techniques: elemental analysis, total organic carbon analysis, UV–vis (ultraviolet–visible spectroscopy, excitation–emission matrix (EEM fluorescence spectroscopy, Fourier transform infrared spectroscopy, and 1H-nuclear magnetic resonance spectroscopy. The results show that HULIS account for 11.2–23.4 and 5.3 % of PM2.5 emitted from biomass burning (BB and coal combustion, respectively. In addition, contributions of HULIS-C to total carbon and water-soluble carbon in smoke PM2.5 emitted from BB are 8.0–21.7 and 56.9–66.1 %, respectively. The corresponding contributions in smoke PM2.5 from coal combustion are 5.2 and 45.5 %, respectively. These results suggest that BB and coal combustion are both important sources of HULIS in atmospheric aerosols. However, HULIS in diesel soot only accounted for  ∼  0.8 % of the soot particles, suggesting that vehicular exhaust may not be a significant primary source of HULIS. Primary HULIS and atmospheric HULIS display many similar chemical characteristics, as indicated by the instrumental analytical characterization, while some distinct features were also apparent. A high spectral absorbance in the UV–vis spectra, a distinct band at λex∕λem ≈  280∕350 nm in EEM spectra, lower H ∕ C and O ∕ C molar ratios, and a high content of [Ar–H] were observed for primary HULIS. These results suggest that primary HULIS contain more aromatic structures, and have a lower content of aliphatic and oxygen-containing groups than atmospheric HULIS. Among the four primary sources of HULIS

  20. Immersion Freezing of Water and Aqueous Ammonium Sulfate Droplets Initiated by Humic-Like Substances as a Function of Water Activity

    Science.gov (United States)

    Rigg, Y.; Alpert, P. A.; Knopf, D. A.

    2013-12-01

    Immersion freezing of water and aqueous (NH4)2SO4 droplets containing leonardite (LEO) and pahokee peat (PP) serving as surrogates for humic-like substances (HULIS) has been investigated. Organic aerosol containing HULIS are ubiquitous in the atmosphere; however, their potential for ice cloud formation is uncertain. Immersion freezing has been studied for temperatures as low as 215 K and solution water activity, aw, from 0.85 to 1.0. The freezing temperatures of water and aqueous solution droplets containing LEO and PP are 5-15 K warmer than homogeneous ice nucleation temperatures. Heterogeneous freezing temperatures can be represented by a horizontal shift of the ice melting curve as a function of solution aw and Δaw by 0.2703 and 0.2466, respectively. Corresponding heterogeneous ice nucleation rate coefficients, Jhet, are (9.6×2.5)x104 and (5.4×1.4)x104 cm-2 s-1 for LEO and PP containing droplets, respectively, and remain constant along freezing curves characterized by Δaw. Consequently predictions of freezing temperatures and kinetics can be made without knowledge of the solute type when relative humidity and ice nuclei (IN) surface areas are known. The acquired ice nucleation data are applied to evaluate different approaches to fit and reproduce experimentally derived frozen fractions. In addition, we apply a basic formulation of classical nucleation theory (α(T)-model) to calculate contact angles and frozen fractions. Contact angles calculated for each ice nucleus as a function of temperature, α(T)-model, reproduce exactly experimentally derived frozen fractions without involving free-fit parameters. However, assigning the IN a single contact angle for the entire population (single-α model) is not suited to represent the frozen fractions. Application of α-PDF, active sites, and deterministic model approaches to measured frozen fractions yield similar good representations. Furthermore, when using a single parameterization of α-PDF or active sites

  1. INFLUENCE OF HUMIC NATURE SUBSTANCES (LG ON THE POLYPEPTIDE POLYMORPHISMS OF SOME GLYCINE MAX L. SORTS WITH DIFFERENT RESISTANCE TO DROUGHT

    Directory of Open Access Journals (Sweden)

    Ana BIRSAN

    2013-12-01

    Full Text Available The content and quality of proteins are genetically determined characters. Individual complex of soybean proteins determines the economic values of the species. In order to identify the particularities of plant response to humic compounds, the polypeptide spectrum of soybean proteins extracted from seeds of two varieties with different drought resistant was analysed. The comparative analysis of protein spectra of extracted proteins from beans of the control plants highlighted the presence of common polypeptides to both studied sorts, and the presence of specific polypeptides for each genotype with a varying amount share appreciated through colorant intensity and band dimension. Protein spectra included polypeptide bands with molecular mass comprised between 106 and 20 kDa. Notable qualitative differences between polypeptide pattern of genotype with medium resistance to drought (Horboveanca and those resistant (S4-04 were detected at the polypeptide level with Mr 104, 60, 43 kDa, present in resistant genotype and absent in medium resistant. Under our previous research was established that treatment of seeds with humic compound (LG significantly increase productivity of soybean plants growing under field conditions, which determined substantial changes in the protein content and enhance grain biomass. From the reported data we conclude that the chemical compounds such as humic compounds may influence production potential of soybean and resulted substantial changes in the protein complex of the plant.

  2. Bioactivity of mangrove humic materials on Rizophora mangle and ...

    African Journals Online (AJOL)

    In this study, we observed the effect of humic substances, humic acids and fulvic acids isolated from sediments of a mangrove forest, sampled from the Municipal Ecological Station Ilha do Lameirão (EEMIL, located in Vitória, Espírito Santo State, Brazil), on the growth and root acidification of Rizophora mangle and ...

  3. Stocks of carbon, total nitrogen and humic substances in soil under different cropping systemsEstoques de carbono e nitrogênio totais nas substâncias húmicas do solo sob diferentes sistemas de manejo

    Directory of Open Access Journals (Sweden)

    Diovany Doffinger Ramos

    2013-10-01

    Full Text Available This study aimed to evaluate total carbon and nitrogen and stocks of the humic fractions of soil organic matter under different cropping systems at the experimental farm at the Federal University at Grande Dourados – UFGD. Soil samples were collected from two layers (0-10 and 10-20 cm from an oxisol with a clay texture. The systems studied were as follows: non-tillage (NTS, tillage (TS, eucalyptus and pasture. Natural vegetation from Dourados, Mato Grosso do Sul, Brazil was used for comparison. For statistical analysis of the C and N stocks, the model: Y = ? + Ai + rep (A ik + Eijk was used. The replacement of TN one for CT decreased the total organic carbon and C in the stocks of humic substances (fulvic acid, humic acid and humin in the soil just three years after adoption, especially in the 0-10 cm layer. However, soils under eucalyptus trees acquired increased carbon stock in the most active fractions, such as the fractions of fulvic and humic acids (0-20 cm layer. Regardless of the cropping system, the largest C and N stocks were measured for the humin fraction, followed by humic acid and fulvic acid. The total N and humic and fulvic acid levels under the conditions of maintenance of TN for 15 years increased when compared with CT, but not in soils under eucalyptus trees.O objetivo deste trabalho foi determinar os estoques de C e N totais nas frações húmicas da matéria orgânica, em diferentes sistemas de manejo do solo na fazenda experimental da Universidade Federal da Grande Dourados – UFGD. Para isso, foram coletadas amostras (0-10 e 10-20 cm em um Latossolo Vermelho distroférrico, textura argilosa, nos sistemas de plantio direto (SPD e convencional (SPC, e os solos cultivados com pastagem e com eucalipto, como referência foi utilizado solo coletado em área de floresta nativa, em Dourados-MS. Para análise estatística dos estoques de C e N foi utilizado o modelo estatístico: Y = ? + Ai + rep(Aik + Eijk. A substituição do

  4. Enzymatically mediated incorporation of 2-chlorophenol 4-chlorophenol into humic acids

    DEFF Research Database (Denmark)

    Lassen, P.; Randall, A.; Jørgensen, O.

    1994-01-01

    A possible route to chlorinated humic substances in the environment, is an indirect chlorination of humic material by enzymatically mediated incorporation of low molecular weight organo-chlorine compounds into the humic skeleton. The enzymatically mediated incorporation of 2-chlorophenol and 4-ch......-chlorophenol into humic acids by Horseradish Peroxidase is reported. The incorporation is accompanied by a significant polymerization of the chlorophenols. The stability of the chlorinated humic acids as well as the environmental implication are discussed.......A possible route to chlorinated humic substances in the environment, is an indirect chlorination of humic material by enzymatically mediated incorporation of low molecular weight organo-chlorine compounds into the humic skeleton. The enzymatically mediated incorporation of 2-chlorophenol and 4...

  5. Np(V) reduction by humic acid: Contribution of reduced sulfur functionalities to the redox behavior of humic acid

    Energy Technology Data Exchange (ETDEWEB)

    Schmeide, K., E-mail: k.schmeide@hzdr.de; Sachs, S.; Bernhard, G.

    2012-03-01

    The role of sulfur-containing functional groups in humic acids for the Np(V) reduction in aqueous solution has been studied with the objective to specify individual processes contributing to the overall redox activity of humic substances. For this, humic acid model substances type M1-S containing different amounts of sulfur (1.9, 3.9, 6.9 wt.%) were applied. The sulfur functionalities in these humic acids are dominated by reduced-sulfur species, such as thiols, dialkylsulfides and/or disulfides. The Np(V) reduction behavior of these humic acids has been studied in comparison to that of the sulfur-free humic acid type M1 at pH 5.0, 7.0 and 9.0 under anaerobic conditions by means of batch experiments. For Np redox speciation in solution, solvent extraction and ultrafiltration were applied. In addition, redox potentials of the sample solutions were monitored. At pH 5.0, both rate and extent of Np(V) to Np(IV) reduction were found to increase with increasing sulfur content of the humic acids. At pH 7.0 and 9.0, sulfur functional groups had only a slight influence on the reduction behavior of humic acid toward Np(V). Thus, in addition to quinoid moieties and non-quinoid phenolic OH groups, generally acknowledged as main redox-active sites in humic substances, sulfur functional groups have been identified as further redox-active moieties of humic substances being active especially in the slightly acidic pH range as shown for Np(V). Due to the low sulfur content of up to 2 wt.% in natural humic substances, their contribution to the total reducing capacity is smaller than that of the other redox-active functional groups. - Highlights: Black-Right-Pointing-Pointer Redox processes of humic substances control the speciation and mobility of metal ions in the environment. Black-Right-Pointing-Pointer Sulfur functional groups were identified as further redox-active sites in humic substances toward Np(V). Black-Right-Pointing-Pointer The specification of processes contributing to

  6. Investigation of the complexation and the migration of actinides and non-radioactive substances with humic acids under geogenic conditions. Complexation of humic acids with actinides in the ocidation state IV Th, U, Np

    Energy Technology Data Exchange (ETDEWEB)

    Sachs, S.; Schmeide, K.; Brendler, V.; Krepelova, A.; Mibus, J.; Geipel, G.; Heise, K.H.; Bernhard, G.

    2004-03-01

    Objective of this project was the study of basic interaction and migration processes of actinides in the environment in presence of humic acids (HA). To obtain more basic knowledge on these interaction processes synthetic HA with specific functional properties as well as {sup 14}C-labeled HA were synthesized and applied in comparison to the natural HA Aldrich. One focus of the work was on the synthesis of HA with distinct redox functionalities. The obtained synthetic products that are characterized by significantly higher Fe(III) redox capacities than Aldrich HA were applied to study the redox properties of HA and the redox stability of U(VI) humate complexes. It was confirmed that phenolic OH groups play an important role for the redox properties of HA. However, the results indicate that there are also other processes than the single oxidation of phenolic OH groups and/or other functional groups contributing to the redox behavior of HA. A first direct-spectroscopic proof for the reduction of U(VI) by synthetic HA with distinct redox functionality was obtained. The complexation behavior of synthetic and natural HA with actinides (Th, Np, Pu) was studied. Structural parameters of Pu(III), Th(IV), Np(IV) and Np(V) humates were determined by X-ray absorption spectroscopy (XAS). The results show that carboxylate groups dominate the interaction between HA and actinide ions. These are predominant monodentately bound. The influence of phenolic OH groups on the Np(V) complexation by HA was studied with modified HA (blocked phenolic OH groups). The blocking of phenolic OH groups induces a decrease of the number of maximal available complexing sites of HA, whereas complex stability constant and Np(V) near-neighbor surrounding are not affected. The effects of HA on the sorption and migration behavior of actinides was studied in batch and column experiments. Th(IV) sorption onto quartz and Np(V) sorption onto granite and its mineral constituents are affected by the pH value

  7. Distribuição e caracterização de substâncias húmicas em vermicompostos de origem animal e vegetal Distribution and characterization of humic substances in animal and plant vermicompost

    Directory of Open Access Journals (Sweden)

    Rosa Maria Vargas Castilhos

    2008-12-01

    residues to human health and soil. The stability and maturity degrees of a given vermicompost are usually inferred from the quantity and quality of the humic substances in the resulting compost. This study aimed to evaluate the quality and maturity of vermicomposts from six different residues: cattle manure (CM, sheep manure (SM, pig manure (PM, quail manure (QM, coffee dregs (CD and mate-tee dregs (MD, by determining the content of humic substances (humic, HA, and fulvic acids (FA and their chemical composition, after 70 days of composting. The humic substances were chemically fractionated according to their solubility in basic and acidic medium. The distribution of total C in the different humic fractions was determined, and the humification indices HA percentage and HA/FA ratio were calculated. The elemental composition (CHNO and chemical composition by infrared spectroscopy (IRSP were determined in the purified HA and FA. An aromaticity index (I1(630/I2920 was calculated based on the IRSP spectra. The vermicomposts differed in humic substance content (FA+HA, which decreased in the order CD > SM ≈ MD ≈ CM > PM > QM. The maturity degree was greater in the vermicomposts of vegetal residues (coffee and mate-tee dregs. The HA showed that the proportion of O containing functional groups and the aromatic degree were lowest in these two vermicomposts.

  8. Influência das características das substâncias húmicas na eficiência da coagulação com sulfato de alumínio The influence of humic substances characteristics on the coagulation efficiency using aluminum sulfate

    Directory of Open Access Journals (Sweden)

    Sandro Xavier Campos

    2005-09-01

    Full Text Available Neste trabalho foi estudada a influência das características das substâncias húmicas (SH, em especial a massa molar das moléculas, na eficiência da coagulação com o uso do sulfato de alumínio. Utilizando-se de água proveniente de poço profundo, foram preparadas quatro águas de estudo, todas com cor verdadeira de aproximadamente 100 uH. As SH foram extraídas de turfa e fracionadas em massas molares: i SH filtradas em membranas de 0,45 µm; ii SH filtradas em membranas de 0,45 µm e maiores que 100 kDa, iii SH com moléculas entre 30 e 100 kDa; iv SH com moléculas menores do que 30 kDa. Verificou-se que quanto maior a massa molar das SH maior foi a eficiência de remoção da cor aparente, com as menores dosagens de coagulante.O pH de coagulação ótimo, esteve entre 6,0 e 7,0, para todas as águas de estudo. Os estudos da porcentagem de ácido húmico (AH e ácido fúlvico (AF presentes em cada fração de diferente massa molar mostraram que quanto maior foi à porcentagem de AF presente, maior foi à dosagem de coagulante exigida para se obter os melhores resultados de remoção da cor aparente.The influence of the molecular weight of soil humic substances on the coagulation efficiency with aluminum sulfate was studied in this work. Four types of water were studied, with the same true color of approximately 100 HU, but prepared with different fractions of molecular weights: Water Type 1 (humic substances filtered in membrane of 0,45 µm; Water Type 2 (humic substances filtered in membrane of 0,45 µm and with molecular weight > 100 KDa; Water Type 3 (humic substances with molecular weight between 100 and 30 KDa; Water Type 4 (humic substances with molecular weight < 30 KDa. It was conclude that the higher the molecular weight of the molecules, the lower the coagulant dosages required for efficient coagulation, at the coagulation pH range 6 - 7. The types of water prepared with the fractions of humic substances containing higher

  9. Fruit production and quality of guava 'Paluma' as a function of humic ...

    African Journals Online (AJOL)

    The uses of humic substances and organic residues for soil mulching have been more common during last years. This way, an experiment was carried out to evaluate the fruit quality and yield of guava cv. Paluma as a function of humic substances and organic soil mulching in Brazil. The experiment was performed from ...

  10. Novel concepts for preparation of reference materials as whole water samples for priority substances at nanogram-per-liter level using model suspended particulate matter and humic acids.

    Science.gov (United States)

    Elordui-Zapatarietxe, Saioa; Fettig, Ina; Philipp, Rosemarie; Gantois, Fanny; Lalère, Béatrice; Swart, Claudia; Petrov, Panayot; Goenaga-Infante, Heidi; Vanermen, Guido; Boom, Gerard; Emteborg, Håkan

    2015-04-01

    One of the unresolved issues of the European Water Framework Directive is the unavailability of realistic water reference materials for the organic priority pollutants at low nanogram-per-liter concentrations. In the present study, three different types of ready-to-use water test materials were developed for polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs) and tributyltin (TBT) at nanogram-per-liter levels. The first type simulated the dissolved phase in the water and comprised of a solution of humic acids (HA) at 5 mg L(-1) dissolved organic carbon (DOC) and a spike of the target compounds. The second type of water sample incorporated the particulate phase in water. To this end, model suspended particulate matter (SPM) with a realistic particle size was produced by jet milling soil and sediments containing known amounts of PAHs, PBDEs and TBT and added as slurry to mineral water. The most complex test materials mimicked "whole water" consequently containing both phases, the model SPM and the HA solution with the target analytes strongly bound to the SPM. In this paper, the development of concepts, processing of the starting materials, characterisation of the HA and model SPMs as well as results for homogeneity and stability testing of the ready-to-use test materials are described in detail.

  11. Modified Sample Preparation Approach for the Determination of the Phenolic and Humic-Like Substances in Natural Organic Materials By the Folin Ciocalteu Method.

    Science.gov (United States)

    Pontoni, Ludovico; Panico, Antonio; Matanò, Alessia; van Hullebusch, Eric D; Fabbricino, Massimiliano; Esposito, Giovanni; Pirozzi, Francesco

    2017-12-06

    A novel modification of the sample preparation procedure for the Folin-Ciocalteu colorimetric assay for the determination of total phenolic compounds in natural solid and semisolid organic materials (e.g., foods, organic solid waste, soils, plant tissues, agricultural residues, manure) is proposed. In this method, the sample is prepared by adding sodium sulfate as a solid diluting agent before homogenization. The method allows for the determination of total phenols (TP) in samples with high solids contents, and it provides good accuracy and reproducibility. Additionally, this method permits analyses of significant amounts of sample, which reduces problems related to heterogeneity. We applied this method to phenols-rich lignocellulosic and humic-like solids and semisolid samples, including rice straw (RS), peat-rich soil (PS), and food waste (FW). The TP concentrations measured with the solid dilution (SD) preparation were substantially higher (increases of 41.4%, 15.5%, and 59.4% in RS, PS and FW, respectively) than those obtained with the traditional method (solids suspended in water). These results showed that the traditional method underestimates the phenolic contents in the studied solids.

  12. Electronic Science Seminar

    Directory of Open Access Journals (Sweden)

    Geidarov P.Sh.

    2015-09-01

    Full Text Available The structure of electronic scientific seminar, which provides a high level of quality of the objectivity in the evaluation of scientific papers, including dissertations, is described. Conditions for the implementation of electronic scientific seminar are also considered.

  13. Characterization of Humic Acid from the River Bottom Sediments of Burigonga: Complexation Studies of Metals with Humic Acid

    Directory of Open Access Journals (Sweden)

    Mohammad Arifur Rahman

    2010-06-01

    Full Text Available In order to characterize and study of the complexation of humic acid with metal ions, sediment samples were collected from five different places in the Buriganga River. The Humic Acids were extracted with the standard procedure provided by the International Humic Substance Society (IHSS. The extracted Humic Acids were characterized with FTIR, EDX and CHNS analyzer and a comparison between the standard and extracted HA was carried out. High C/N ratios (71.48-87.36 are observed in the CHNS analysis. A complexation study of the Humic Acid with iron (III and cadmium (II was also carried out using EDX, UV-Visible spectrophotometer and AAS techniques. The coagulation behavior was observed with Jar test. From the study, it was found that iron and cadmium could make a complex at pH 6.0 which was confirmed by EDX (Electron Dispersive x-ray.

  14. Oxidizable carbon and humic substances in rotation systems with brachiaria/livestock and pearl millet/no livestock in the Brazilian Cerrado

    Directory of Open Access Journals (Sweden)

    A. Loss

    2013-02-01

    Full Text Available The crop-livestock integration system significantly increases the carbon content in chemical fractions of soil organic matter (SOM. This study aimed to evaluate chemical indicators of SOM attributes for sites under brachiaria/livestock and pearl millet/no livestock in Goias, Brazil. A third area covered with natural Cerrado vegetation (Cerradão served as reference. Soil was randomly sampled at 0-5, 5-10, 10-20 and 20-40 cm. Total organic carbon stocks (TOC, oxidizable carbon fractions (OCF (F1>F2>F3>F4, carbon content in the humin (C-HUM, humic acid (C-HAF and fulvic acid (C-FAF fractions were evaluated. F1/F4, F1+F2/F3+F4, C-HAF/C-FAF and (C-HAF+C-FAF/C-HUM indices were calculated, as well as stocks chemical SOM fractions. Brachiaria/livestock produced greater TOC stocks than pearl millet/no livestock (0-5, 5-10 and 10-20 cm. In terms of OCF, brachiaria/livestock generally exhibited higher levels in F1, F2, F4 and F1/F4 than pearl millet/no livestock. C-HUM (0-10 cm and C-HAF (0-20 cm stocks were larger in brachiaria/livestock than pearl millet/no livestock. Compared to the Cerradão, brachiaria/livestock locations displayed higher values for TOC (5-10 and 10-20 cm, C-HAF and C-HAF/C-FAF (5-10 cm stocks. TOC, C-HAF stock and OCF show that land management with brachiaria/livestock was more efficient in increasing SOM than pearl millet/no livestock. Moreover, when compared with pearl millet/no livestock, brachiaria/livestock provided a more balanced distribution of very labile (F1 and recalcitrant (F4 carbon throughout soil layers, greater SOM humification. Brachiaria/livestock leads to higher values of F1 and F4 in depth when compared to pearl millet/livestock and provides a more homogeneous distribution of C-FAF and C-HAF in depth compared to Cerradão.

  15. Technical Training Seminar

    CERN Document Server

    2003-01-01

    Wednesday 19 November From 9:30 to 17:30 - IT Amphitheatre bldg.31 3-004 2003 Data Transmission Design Seminar - TEXAS INSTRUMENTS The one-day 2003 Data Transmission Design Seminar is part of a series of technical seminars produced by Texas Instruments. This series of seminars will introduce system solutions based on different standards according to their respective requirements. It will include topics containing a blend of basic principles and hands-on application examples, along with layout-guidelines. • Basics and Practical Examples of Data-Transmission • Low Voltage Differential Signaling (LVDS) • Connectivity and PC-based Links • Industrial Interfaces • Parallel Bus Systems and Clock-Distribution-Circuits (CDC) This Seminar will be of interest to hardware designers and system engineers dealing with the realization of system- or board-level interfaces based on various transmission standards. Language: English Free seminar, no registration Organiser: John ...

  16. Comparative study for separation of atmospheric humic-like substance (HULIS) by ENVI-18, HLB, XAD-8 and DEAE sorbents: elemental composition, FT-IR, 1H NMR and off-line thermochemolysis with tetramethylammonium hydroxide (TMAH).

    Science.gov (United States)

    Fan, Xingjun; Song, Jianzhong; Peng, Ping'an

    2013-11-01

    Humic-like substances (HULIS) are significant constituents of aerosols, and the isolation and characterization of HULIS by solid-phase extraction methods are dependent on the sorbents used. In this study, we used the following five methods: ENVI-18, HLB-M, HLB-N, XAD-8 and DEAE, to isolate atmospheric HULIS at an urban site. Then we conducted a comparative investigation of the HULIS chemical characteristics by means of elemental analysis, Fourier transform infrared spectroscopy, (1)H nuclear magnetic resonance spectroscopy and off-line thermochemolysis with tetramethylammonium hydroxide. The results indicate that HULIS isolated using different methods show many similarities in chemical composition and structure. Some differences were however also observed between the five isolated HULIS: HULISHLB-M contains a relatively high content of OCH group, compared to HULISENVI-18 and HULISXAD-8; HULISXAD-8 contains a relatively high content of hydrophobic and aromatic components, compared to HULISENVI-18 and HULISHLB-M; HULISDEAE contains the highest content of aromatic functional groups, as inferred by (1)H NMR spectra, but a great amount of salts generally present in the HULISDEAE and thereby limited the choices for characterizing the materials (i.e., elemental analysis and TMAH thermochemolysis); HULISHLB-N has relatively high levels of H and N, a high N/C atomic ratio, and includes N-containing functional groups, which suggests that it has been altered by 2% ammonia introduced in the eluents. In summary, we found that ENVI-18, HLB-M, and XAD-8 are preferable methods for isolation and characterization of HULIS in atmospheric aerosols. These results also suggest that caution is required when applying DEAE and HLB-N isolating methods for characterizing atmospheric HULIS. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Atmospheric HULIS: How humic-like are they? A comprehensive and critical review

    Directory of Open Access Journals (Sweden)

    E. R. Graber

    2006-01-01

    Full Text Available A class of organic molecules extracted from atmospheric aerosol particles and isolated from fog and cloud water has been termed HUmic-LIke Substances (HULIS due to a certain resemblance to terrestrial and aquatic humic and fulvic acids. In light of the interest that this class of atmospheric compounds currently attracts, we comprehensively review HULIS properties, as well as laboratory and field investigations concerning their formation and characterization in atmospheric samples. While sharing some important features such as polyacidic nature, accumulating evidence suggests that atmospheric HULIS differ substantially from terrestrial and aquatic humic substances. Major differences between HULIS and humic substances, including smaller average molecular weight, lower aromatic moiety content, greater surface activity, better droplet activation ability, as well as others, are highlighted. Several alternatives are proposed that may explain such differences: (1 the possibility that mono- and di-carboxylic acids and mineral acids abundant in the atmosphere prevent the formation of large humic 'supramolecular associations'; (2 that large humic macromolecules are destroyed in the atmosphere by UV radiation, O3, and OH- radicals; (3 that 'HULIS' actually consists of a complex, unresolved mixture of relatively small molecules rather than macromolecular entities; and (4 that HULIS formed via abiotic and short-lived oxidative reaction pathways differ substantially from humic substances formed over long time periods via biologically-mediated reactions. It should also be recalled that the vast majority of studies of HULIS relate to the water soluble fraction, which would include only the fulvic acid fraction of humic substances, and exclude the humic acid (base-soluble and humin (insoluble fractions of humic substances. A significant effort towards adopting standard extraction and characterization methods is required to develop a better and meaningful

  18. Influence of Soil Humic and Fulvic Acid on the Activity and Stability of Lysozyme and Urease

    NARCIS (Netherlands)

    Li, Yan; Tan, WenFeng; Koopal, Luuk K.; Wang, MingXia; Liu, Fan; Norde, Willem

    2013-01-01

    Humic substances (HS), including humic acids (HA) and fulvic acids (FA), are important components of soil systems. HS form strong complexes with oppositely charged proteins, which will lead to changes in the enzyme activity. The effect of soil HS on the activity and stability of two enzymes was

  19. Interpretation of humic acid coagulation and soluble soil organic matter using a calculated electrostatic potential

    NARCIS (Netherlands)

    Weng, L.P.; Temminghoff, E.J.M.; Riemsdijk, van W.H.

    2002-01-01

    The coagulation of humic substances and its role in controlling the solubility of organic matter in soils are not well understood. We therefore studied the physico-chemical behaviour of purified humic acid from forest soil coagulated with Na, Ca, Cu, Al at pH 4 and 6, and then modelled the behaviour

  20. Hollow fiber dead-end ultrafiltration: Axial transport variations during humic acid filtration

    NARCIS (Netherlands)

    van de Ven, W.J.C.; van 't Sant, K.; Punt, Ineke G.M.; Zwijnenburg, A.; Kemperman, Antonius J.B.; van der Meer, Walterus Gijsbertus Joseph; Wessling, Matthias

    2008-01-01

    This paper describes the dead-end ultrafiltration of humic substances with hollow fiber modules. We show that the resistance of a fouling layer decreases with increasing flux. The lower resistance of the fouling layer is caused by a loss in retention of the membrane for humic acid at these higher

  1. Influence of soil humic and fulvic acid on the activity and stability of lysozyme and urease

    NARCIS (Netherlands)

    Li, Y.; Tan, W.; Koopal, L.K.; Wang, M.; Liu, Fan; Norde, W.

    2013-01-01

    Humic substances (HS), including humic acids (HA) and fulvic acids (FA), are important components of soil systems. HS form strong complexes with oppositely charged proteins, which will lead to changes in the enzyme activity. The effect of soil HS on the activity and stability of two enzymes was

  2. Virtual Seminar Room

    DEFF Research Database (Denmark)

    Forchhammer, Søren Otto; Fosgerau, Anders; Hansen, Peter Søren Kirk

    1999-01-01

    The initial design considerations and research goals for an ATM network based virtual seminar room with 5 sites are presented.......The initial design considerations and research goals for an ATM network based virtual seminar room with 5 sites are presented....

  3. SEMINAR IN MUSIC EDUCATION.

    Science.gov (United States)

    PALISCA, CLAUDE V.

    A SEMINAR ON MUSIC EDUCATION WAS ORGANIZED TO BRING THE WIDEST POSSIBLE VARIETY OF MUSICAL COMPETENCE AND INTERESTS TO BEAR UPON PROBLEMS IN SCHOOL MUSIC. THE THREE CENTRAL PROBLEM AREAS PUT BEFORE THE SEMINAR WERE (1) DEVELOPMENT OF MUSICALITY THROUGH PLAYING, SINGING, AND CREATING MUSIC, AND THROUGH LISTENING AND EAR TRAINING, (2) CRITERIA FOR…

  4. Influence of different kind of peats on some physic-chemical properties, biochemical activity, the content of different forms of nitrogen and fractions of humic substances of The Great Vasyugan Mire

    Science.gov (United States)

    Inisheva, L. I.; Szajdak, L.

    2009-04-01

    Mires, or peatlands belong to the wetlands ecosystems where carbon is bounded in primary production and deposited as peat in water saturated, anoxic conditions. In those conditions, the rate of the supply of new organic matter has exceeded that the decomposition, resulting in carbon accumulation. Place of sampling belongs to an oligotrophic landscapes of the river Klyuch basin in spurs of Vasyugan mire. The catchment represents reference system for Bokchar swampy area (political district of Tomsk region). Landscape profile crosses main kinds of swampy biogeocoenosis (BGC) toward the mire center: paludal tall mixed forest, pine undershrub Sphagnum (high riam, trans-accumulative part of a profile, P2), pine-undershrub Sphagnum (low riam, transit part, P3), sedge-moss swamp (eluvial part, P5). The latter represents an eluvial part of a slope of watershed massif where it is accomplished discharge of excess, surface, soil-mire waters. The depth of peat deposit of sedge-moss swamp reaches 2,5m. To the depth of 0,6m there is a layer of Sphagnum raised bog peat, then it is a mesotrophic Scheuchzeria Sphagnum layer and at the bottom there is a thick layer of low-mire horsetail peat. The samples of peats were taken from two places (P2 and P3), both from the depth 0-75 cm of the great Vasyugan Mire. These materials represent (P2) Sphagnum fuscum peat (ash content ranged from 10.8 to 15.1%), but samples P3 belong to low-moor sedge peat (ash content ranged from 4.5-4.8%). The differences in water level, redox potential, pH, degree of degradation, bulk density, number of microorganisms, activity of enzymes, different kinds of nitrogen and humic substances were studied in two different peat soils characterized by different type of peat. In general in P2 the redox potential changed from 858 to /-140/ mV, higher activity of xanthine oxidase and peroxidase, different kinds of microorganisms (ammonifing bacteria and cellulose decomposing microorganisms) and different kinds of

  5. EUROTHERM Seminar No. 18

    CERN Document Server

    Heggs, Peter; Butterworth, David

    1992-01-01

    The Eurotherm Committee was created in 1986 from member countries of the European Community. It has the purpose of organising and coordinating scientific events such as seminars and conferences in the thermal sciences. The series of Eurotherm Seminars established by the Committee has become a popular forum for high-level scientific and technical interchange of ideas in a wide range of specialist topics. While the presentation and publication of papers at the Seminars are encouraged, the primary aim is to stimulate discussion and liaison between specialist groups. The present Chairman of Eurotherm is Professor C.J. Hoogendoorn of the Technical University, Delft (Fax [NL] 15, 783251). Information on Mure Seminars is available from the Secretary, Keith Cornwell, Heriot-Watt University, Edinburgh (Fax [UK] 31, 451, 3129). This particular Seminar No. 18 on the Design and Operation of Heat Exchangers was the first one on this topic and was held at the Universitat der Bundeswehr Hamburg (University of the Federal Ar...

  6. Seminar proceedings. Seminar on piping reliability

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-10-01

    The international seminar brought together the disciplines of probabilistic safety assessment and probabilistic fracture mechanics. The work performed by the joint Nordic Nuclear Safety Research Project NKS/RAK 1.2 and the SLAP project was presented the first day. The second was mainly devoted to the integration of the two disciplines. 11 contributions have been separately indexed.

  7. Comparison of some spectroscopic and physico-chemical properties of humic acids extracted from sewage sludge and bottom sediments

    Science.gov (United States)

    Polak, J.; Bartoszek, M.; Sułkowski, W. W.

    2009-04-01

    Comparison of the physico-chemical properties was carried out for humic acids extracted from sewage sludge and bottom sediments. The isolated humic acids were investigated by means of EPR, IR, UV/vis spectroscopic methods and elementary analysis AE. On the basis of earlier studies it was stated that humic acids extracted from sewage sludge can be divided into humic acids extracted from raw sewage sludge and from sewage sludge after the digestion process. The digestion process was found to have the most significant effect on the physico-chemical properties of humic acids extracted from sludge during sewage treatment. Humic acids extracted from sewage sludge had higher free radical concentration than humic acid extracted from bottom sediments. Values of the g-factor were similar for all studied samples. However, it is noteworthy that g-factor values for humic acid extracted from raw sewage sludge and from bottom sediments were lower in comparison to the humic acid extracted from sewage sludge after the fermentation processes. The IR spectra of all studied humic acids confirmed the presence of functional groups characteristic for humic substances. It was also observed that humic acids extracted from bottom sediments had a more aromatic character and contained less carbon, nitrogen and hydrogen than those extracted from the sewage sludge.

  8. Symmetric Cryptography (Dagstuhl Seminar 16021)

    OpenAIRE

    Armknecht, Frederik; Iwata, Tetsu; Nyberg, Kaisa; Preneel, Bart

    2016-01-01

    From 10.01.2016 to 15.01.2016, the Seminar 16021 in Symmetric Cryptography was held in Schloss Dagstuhl-Leibniz Center for Informatics. It was the fifth in the series of the Dagstuhl seminars "Symmetric Cryptography" held in 2007, 2009, 2012, and 2014. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations were given during the seminar. The first section describes the seminar topics and g...

  9. Sustainable roadway lighting seminar.

    Science.gov (United States)

    2014-07-01

    The objective of this project was to develop and conduct a half-day educational seminar on sustainable : roadway lighting at three locations within New York State: Rochester, New York City, and Albany. : Primary attendees were engineers from the New ...

  10. Characterization of the interaction of uranyl ions with humic acids by x-ray absorption spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Reich, T.; Denecke, M.A.; Pompe, S. [Inst. of Radiochemistry, Dresden (Germany)] [and others

    1995-11-01

    Humic substances are present throughout the environment in soil and natural water. They are organic macromolecules with a variable structural formula, molecular weight, and a wide variety of functional groups depending on their origin. In natural waters, humic substances represent the main component of the {open_quotes}dissolved organic carbon{close_quotes} (DOC). The DOC may vary considerably from 1 mg/L at sea water surfaces to 50 mg/L at the surface in dark water swamps. There is strong evidence that all actinides form complexes with humic substances in natural waters. Therefore, humic substances can play an important role in the environmental migration of radionuclides by enhancing their transport. Retardation through humic substance interaction may be also possible due to formation of precipitating agglomerates. For remediation and restoration of contaminated environmental sites and risk assessment of future nuclear waste repositories, it is important to improve the predictive capabilities for radionuclide migration through a better understanding of the interaction of radionuclides with humic substances.

  11. COMBINE 2 seminar

    DEFF Research Database (Denmark)

    Sørensen, Lars Schiøtt; Jacobsen, Kim

    1995-01-01

    A seminar about the COMBINE project was described. Further, the project was described in generel, i.e. the COMBINE´s data model (IDM), the data exchange system (DES) and the different I/O-systems included in COMBINE 2......A seminar about the COMBINE project was described. Further, the project was described in generel, i.e. the COMBINE´s data model (IDM), the data exchange system (DES) and the different I/O-systems included in COMBINE 2...

  12. Behaviour of humic-bentonite aggregates in diluted suspensions ...

    African Journals Online (AJOL)

    Processes of aggregate formation and disaggregation are common in both waters and soils and are widely used in different industries. Aggregates composed of clays and humic substances (HSs) are, either directly or indirectly, associated with almost all biological, chemical, and physical phenomena in waters and soils.

  13. Etiquette in Departmental Seminars

    Science.gov (United States)

    Ram Singh, Bal; Deck, Joseph C.

    1998-07-01

    Participation in seminars is a common form of communication within the scientific community and is being increasingly required in the undergraduate curriculum, either formally or informally, in many universities and colleges. Seminars can provide unique opportunities for both updating and learning new cutting-edge knowledge in different branches of chemistry. The interdisciplinary nature of the divisions of chemistry gives students the opportunity to see how much of the information learned in separate courses can be integrated to provide a deeper understanding of the discipline. However, required seminar attendance and participation often creates frustration, and even anger among students, especially if the topics are in areas for which they feel they have no background or if the seminar deliveries are presented at a level beyond their abilities to understand. There is an etiquette of seminar attendance that is worthy of presentation. A list of Do's and Don'ts along with some explanation is presented in this article, which is likely to benefit not only undergraduate and graduate students but also seminar speakers and conveners.

  14. Effects of peat fires on the characteristics of humic acid extracted from peat soil in Central Kalimantan, Indonesia.

    Science.gov (United States)

    Yustiawati; Kihara, Yusuke; Sazawa, Kazuto; Kuramitz, Hideki; Kurasaki, Masaaki; Saito, Takeshi; Hosokawa, Toshiyuki; Syawal, M Suhaemi; Wulandari, Linda; Hendri I; Tanaka, Shunitz

    2015-02-01

    When peat forest fires happen, it leads to burn soil and also humic acids as a dominant organic matter contained in peat soil as well as the forest. The structure and properties of humic acids vary depending on their origin and environment, therefore the transformation of humic acid is also diverse. The impacts of the peat fires on peat soil from Central Kalimantan, Indonesia were investigated through the characterization of humic acids, extracted from soil in burnt and unburnt sites. The characterization of humic acids was performed by elemental composition, functional groups, molecular weight by HPSEC, pyrolysate compounds by pyrolysis-GC/MS, fluorescence spectrum by 3DEEM spectrofluorometer, and thermogravimetry. The elemental composition of each humic substance indicated that the value of H/C and O/C of humic acids from burnt sites were lower than that from unburnt sites. The molecular weight of humic acids from burnt sites was also lower than that from unburnt sites. Pyrolysate compounds of humic acids from unburnt sites differed from those of humic acids from burnt soil. The heating experiment showed that burning process caused the significant change in the properties of humic acids such as increasing the aromaticity and decreasing the molecular weight.

  15. Direct solid surface fluorescence spectroscopy of standard chemicals and humic acid in ternary system.

    Science.gov (United States)

    Mounier, S; Nicolodelli, G; Redon, R; Milori, D M B P

    2017-04-15

    The front face fluorescence spectroscopy is often used to quantify chemicals in well-known matrices as it is a rapid and powerful technique, with no sample preparation. However it was not used to investigate extracted organic matter like humic substances. This work aims to fully investigate for the first time front face fluorescence spectroscopy response of a ternary system including boric acid, tryptophan and humic substances, and two binaries system containing quinine sulfate or humic substance in boric acid. Pure chemicals, boric acid, tryptophan, quinine sulfate and humic acid were mixed together in solid pellet at different contents from 0 to 100% in mass. The measurement of excitation emission matrix of fluorescence (3D fluorescence) and laser induced fluorescence were then done in the front face mode. Fluorescence matrices were decomposed using the CP/PARAFAC tools after scattering treatments. Results show that for 3D fluorescence there is no specific component for tryptophan and quinine sulfate, and that humic substances lead to a strong extinction effect for mixture containing quinine sulfate. Laser induced fluorescence gives a very good but non-specific related response for both quinine sulfate and tryptophan. No humic substances fluorescence response was found, but extinction effect is observed as for 3D fluorescence. This effect is stronger for quinine sulfate than for tryptophan. These responses were modeled using a simple absorbance versus emission model. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Direct solid surface fluorescence spectroscopy of standard chemicals and humic acid in ternary system

    Science.gov (United States)

    Mounier, S.; Nicolodelli, G.; Redon, R.; Milori, D. M. B. P.

    2017-04-01

    The front face fluorescence spectroscopy is often used to quantify chemicals in well-known matrices as it is a rapid and powerful technique, with no sample preparation. However it was not used to investigate extracted organic matter like humic substances. This work aims to fully investigate for the first time front face fluorescence spectroscopy response of a ternary system including boric acid, tryptophan and humic substances, and two binaries system containing quinine sulfate or humic substance in boric acid. Pure chemicals, boric acid, tryptophan, quinine sulfate and humic acid were mixed together in solid pellet at different contents from 0 to 100% in mass. The measurement of excitation emission matrix of fluorescence (3D fluorescence) and laser induced fluorescence were then done in the front face mode. Fluorescence matrices were decomposed using the CP/PARAFAC tools after scattering treatments. Results show that for 3D fluorescence there is no specific component for tryptophan and quinine sulfate, and that humic substances lead to a strong extinction effect for mixture containing quinine sulfate. Laser induced fluorescence gives a very good but non-specific related response for both quinine sulfate and tryptophan. No humic substances fluorescence response was found, but extinction effect is observed as for 3D fluorescence. This effect is stronger for quinine sulfate than for tryptophan. These responses were modeled using a simple absorbance versus emission model.

  17. Humic acid protein complexation

    OpenAIRE

    Tan, W.F.; Koopal, L.K.; Weng, L.P.; Riemsdijk, van, J.F.; Norde, W.

    2008-01-01

    Interactions of purified Aldrich humic acid (PAHA) with lysozyme (LSZ) are investigated. In solution LSZ is moderately positively and PAHA negatively charged at the investigated pH values. The proton binding of PAHA and of LSZ is determined by potentiometric proton titrations at various KCl concentrations. It is also measured for two mixtures of PAHA¿LSZ and compared with theoretically calculated proton binding assuming no mutual interaction. The charge adaptation due to PAHA¿LSZ interaction ...

  18. Interaction of Humic Acids with Organic Toxicants

    Science.gov (United States)

    Tchaikovskaya, O. N.; Yudina, N. V.; Maltseva, E. V.; Nechaev, L. V.; Svetlichnyi, V. A.

    2016-08-01

    Interaction of humic acids with polyaromatic hydrocarbons (PAH) (naphthalene and anthracene) and triazole series fungicides (cyproconazole (CC) and tebuconazole (TC)) is investigated by the method of fluorescence quenching depending on the concentration of substances in solutions and their structural features. Humic acids were modified by mechanochemical activation in a planetary mill. The complex character of intermolecular interactions between PAH and fungicides with humic acids, including donor-acceptor and hydrophobic binding, is established. Thermodynamically stable conformations of biocide molecules were estimated using ChemOffice CS Chem3D 8.0 by methods of molecular mechanics (MM2) and molecular dynamics. Biocide molecules with pH 7 are in energetically favorable position when the benzene and triazole rings are almost parallel to each other. After acidification of solutions to pH 4.5, the CC molecule retains the geometry for which donor-acceptor interactions are possible: the benzene ring in the molecule represents the electron donor, and triazole is the acceptor. In this case, the electron density in CC is redistributed easier, which is explained by a smaller number of carbon atoms between the triazole and benzene rings, unlike TC. As a result, the TC triazole ring is protonated to a greater degree, acquiring a positive charge, and enters into donoracceptor interactions with humic acid (HA) samples. The above-indicated bond types allow HA to participate actively in sorption processes and to provide their interaction with biocides and PAH and hence, to act as detoxifying agents for recultivation of the polluted environment.

  19. Recovery of humic-reducing bacteria from a diversity of environments.

    Science.gov (United States)

    Coates, J D; Ellis, D J; Blunt-Harris, E L; Gaw, C V; Roden, E E; Lovley, D R

    1998-04-01

    To evaluate which microorganisms might be responsible for microbial reduction of humic substances in sedimentary environments, humic-reducing bacteria were isolated from a variety of sediment types. These included lake sediments, pristine and contaminated wetland sediments, and marine sediments. In each of the sediment types, all of the humic reducers recovered with acetate as the electron donor and the humic substance analog, 2,6-anthraquinone disulfonate (AQDS), as the electron acceptor were members of the family Geobacteraceae. This was true whether the AQDS-reducing bacteria were enriched prior to isolation on solid media or were recovered from the highest positive dilutions of sediments in liquid media. All of the isolates tested not only conserved energy to support growth from acetate oxidation coupled to AQDS reduction but also could oxidize acetate with highly purified soil humic acids as the sole electron acceptor. All of the isolates tested were also able to grow with Fe(III) serving as the sole electron acceptor. This is consistent with previous studies that have suggested that the capacity for Fe(III) reduction is a common feature of all members of the Geobacteraceae. These studies demonstrate that the potential for microbial humic substance reduction can be found in a wide variety of sediment types and suggest that Geobacteraceae species might be important humic-reducing organisms in sediments.

  20. Sustaining an English Faculty Seminar.

    Science.gov (United States)

    Harrington, David V.

    1989-01-01

    Describes several aspects of English faculty seminars at Gustavus Adolphus College, including a description of scheduling procedures; advantages gained for both the department and college; the range of presentations encouraged; and problems solved in order to sustain the seminars. (MM)

  1. Preparation for Retirement Seminar

    CERN Multimedia

    HR Department

    2009-01-01

    The Human Resources Department is organizing a preparation for retirement seminar, which will take place on the afternoons of the 11, 13, 25 and 27 November 2009. Similar seminars in the past have always proved highly successful. Retirement marks the end of a person’s working life and the start of a new chapter. This period of transition is experienced differently from one individual to another. In all cases, being well-informed and prepared greatly facilitates the change in lifestyle. We would like to draw your attention to the following information: Staff concerned: All staff members aged 58 and above have been sent a personal invitation to attend. Spouses are welcome. Staff members below 58 who are interested in attending the seminar may also apply. Their applications will be accepted subject to availability of places. Registration: In view of the number of people concerned and the limited capacity of the main auditorium, you are requested to register in advance via ...

  2. Preparation for Retirement Seminar

    CERN Document Server

    HR Department

    2009-01-01

    The Human Resources Department is organizing a preparation for retirement seminar, which will take place in the afternoons of 11, 13, 25 and 27 November 2009. Similar seminars in the past have always proved highly successful. Retirement marks the end of a person’s working life and the start of a new chapter. This period of transition is experienced differently from one individual to another. In all cases, being well-informed and prepared greatly facilitates the change in lifestyle. We would like to draw your attention to the following information: Staff concerned: All staff members aged 58 and above have been sent a personal invitation to attend. Spouses are welcome. Staff members below 58 who are interested in attending the seminar may also apply. Their applications will be accepted subject to the availability of places. Registration: In view of the number of people concerned and the limited capacity of the Main Auditorium, you are requested to register in advance via Ind...

  3. Preparation for Retirement Seminar

    CERN Multimedia

    HR Department

    2009-01-01

    The Human Resources Department is organizing a preparation for retirement seminar, which will take place on the afternoons of the 11, 13, 25 and 27 November 2009. Similar seminars in the past have always proved highly successful. Retirement marks the end of a person’s working life and the start of a new chapter. This period of transition is experienced differently from one individual to another. In all cases, being well-informed and prepared greatly facilitates the change in lifestyle. We would like to draw your attention to the following information: Staff concerned: All staff members aged 58 and above have been sent a personal invitation to attend. Spouses are welcome. Staff members under the age of 58 who are interested in attending the seminar may also apply. Their applications will be accepted subject to the availability of places. Registration: In view of the number of people concerned and the limited capacity of the Main Auditorium, you are requested to register ...

  4. Preparation for Retirement Seminar

    CERN Multimedia

    HR Department

    2009-01-01

    The Human Resources Department is organizing a preparation for retirement seminar, which will take place on the afternoons of the 11, 13, 25 and 27 November 2009. Similar seminars in the past have always proved highly successful. Retirement marks the end of a person’s working life and the start of a new chapter. This period of transition is experienced differently from one individual to another. In all cases, being well-informed and prepared greatly facilitates the change in lifestyle. We would like to draw your attention to the following information: Staff concerned: All staff members aged 58 and above have been sent a personal invitation to attend. Spouses are welcome. Staff members below 58 who are interested in attending the seminar may also apply. Their applications will be accepted subject to the availability of places. Registration: In view of the number of people concerned and the limited capacity of the Main Auditorium, you are requested to register in advance ...

  5. HUMIC ACID ON GERMINATION AND VIGOR OF CORN SEEDS

    Directory of Open Access Journals (Sweden)

    LENNIS AFRAIRE RODRIGUES

    2017-01-01

    Full Text Available The development of technologies to increase stand establishment efficiency and seed vigor, as well as to maximize profits, is of fundamental importance for the sustainability of agriculture. Products based on humic substances, such as humic acids, have been recently used in Brazilian agriculture to produce seedlings with high vigor, which positively influences the establishment of the initial stand. Thus, this study aimed to evaluate the effect of treatment of corn seeds with a commercial humic acid-based product, Humykos® (18% of humic acid content, on germination and seedling vigor. The treatments consisted of six doses (0, 100, 200, 300, 400, and 500 mL 100 kg-1 seed of Humykos®, and the treated seeds were analyzed for germination and vigor (first count, emergence, emergence speed index, length, and dry mass of shoots and roots. Our results show that humic acid promotes greater seedling growth and increased shoot dry mass in corn; in addition, it has a positive influence on the emergence speed index up to a dose 158 mL 100 kg-1 seeds.

  6. TECHNICAL TRAINING SEMINAR

    CERN Multimedia

    Davide Vitè

    2002-01-01

    Wednesday 6 March TECHNICAL TRAINING SEMINAR from 9:30 to 16:45 - IT Amphitheatre - bldg. 31.3.004 Analog Devices DSP Day Thorsten Kistler (Application Engineer), Steffen Boerner (Product Specialist) / ANALOG DEVICES Munich Trying to meet your design challenges, Analog Devices compiles application information and offers chipsets, software, reference designs and mixed-signal, application specific DSPs, for a range of real-time signal processing applications. This seminar will present the latest 16bit fixed-point and 32bit floating-point DSPs (roadmaps; internal architectures, blocks, features benchmarks), with their software, development kits and emulators: Fixed-Point DSP-Family, ADSP-218x and ADSP-219x Blackfin DSP SHARC-Family, 2106x and 2116x TigerSHARC Industrial Contact: François Caloz, Sasco-Spoerle GmbH Language: English Free seminar, no registration Organiser: Davide Vitè / HR-TD / 75141 Davide.Vite@cern.ch Please read the full information on the Technical Training Seminars...

  7. Seminar on Nanobiotechnology

    Indian Academy of Sciences (India)

    user

    Thane, is organizing a one day National Level Seminar on 'Nanobiotechnology – The Big world of Small things', to be held on 10th January, 2009. Nanotechnology deals with the production of nanoscale particles/devices, which have tremendous potential for use in various fields, such as industry, medicine or environment.

  8. Humic first, A new theory on the origin of life

    Science.gov (United States)

    Daei, Mohammad Ali; Daei, Manijeh

    2016-04-01

    In 1953, Miller &Urey through a brilliant experiment demonstrated that the building blocks of life could evolve in primitive earth conditions1. In recent years scientists revealed that organic matters are not very rare compounds in comets, asteroids, and meteorites2. These facts show simple organic molecules on early earth could be quite enough to start development of life. But, how? Many theorists have tried to explain how life emerged from non life, but failed2. There is a huge gap between the simple building blocks, like amino acid, sugar, and lipid molecules, to a living cell with a very sophisticated structure and organization. Obviously, creation of a cell needed a qualified production line which had to be durable and active, can gather all biochemical ingredients, protect them from degradation, have catalyzing ability, provide numerous opportunities for interaction between basic molecules, and above all, have capability to react to different sources of energy. We are sure this perfect factory was available on primitive earth and is nothing except humic substance! At the moment, HS, are doing nearly all of these duties, among the others, under your feet in agricultural soils4. What are humic substances? According to IHSS definition "Humic substances (HS) are major components of the natural organic matter (NOM) in soil and water as well as in geological organic deposits such as lake sediments, peats, brown coals, and shales5." They come from polymerization of organic molecules, but looking at them like a simple aggregation of different organic molecules, is a huge mistake6! It seems they do not come together except for making a capable structure! HS are the first organic machinery which appeared in proplanetary disk, more than four billion years ago. Derived from simple inorganic molecules, humic substances construct a firm intermediate structure which connects none life to life. In other word, life road pass over the humic bridge. This does not mean that

  9. Reduction and Reoxidation of Humic Acid: Influence on Spectroscopic Properties and Proton Binding

    Energy Technology Data Exchange (ETDEWEB)

    Maurer, F.; Christl, I; Kretzschmar, R

    2010-01-01

    Previous studies on proton and metal binding to humic substances have not considered a potential influence of reduction and oxidation of functional groups. Therefore, we investigated how proton binding of a purified soil humic acid was affected by reduction. Reduction of the humic acid was carried out using an electrochemical cell that allowed us to measure the amounts of electrons and protons involved in reduction reactions. We further applied spectroscopic methods (UV-vis, fluorescence, FT-IR, C-1s NEXAFS) to detect possible chemical changes in the humic acid induced by reduction and reoxidation. The effect of reduction on proton binding was determined with acid-base titrations in the pH range 4-10 under controlled redox conditions. During reduction, 0.54 mol kg{sup -1} protons and 0.55 mol kg{sup -1} electrons were transferred to humic acid. NICA-Donnan modeling revealed an equivalent increase in proton-reactive sites (0.52 mol kg{sup -1}) in the alkaline pH-range. Our results indicate that reduction of humic acid increased the amount of proton-reactive sites by 15% compared to the untreated state. Spectroscopic differences between the untreated and reduced humic acid were minor, apart from a lower UV-vis absorption of the reduced humic acid between 400 and 700 nm.

  10. Impact of humic acids on EYL liposome membranes: ESR method

    Directory of Open Access Journals (Sweden)

    Pytel Barbara

    2015-07-01

    Full Text Available In this paper, the effects of model (commercial and natural (extracted from peat humic substances on the membrane of liposomes formed with egg yolk lecithin (EYL are presented. In our research, mass concentrations of fulvic and humic acids were used, which in relation to lecithin varied from 0% to 13%. To study membrane fluidity, electron spin resonance (EPR was used with two spin probes, penetrating various regions of the lipid bilayer. The effects of model and natural humic substances (humic acids – HAs and fulvic acids – FAs on the lipid membrane in different regions were researched: the lipid-water interphase, and in the middle of the lipid bilayer. It was shown that FA and HA impact the fluidity of liposome membranes in different ways. Increased mass concentrations of HAs decreased membrane fluidity in both acids: extracted from peat and the model. However, increased mass concentration of FAs extracted from peat, decreased membrane fluidity in the surface region, at the same time stiffening the central part of the bilayer. Increasing the concentration of FAs extracted from peat had the opposite effect when compared to model FA. This effect may be related to the complexation of xenobiotics present in the soil environment and their impact on biological membranes.

  11. Humic and fluvic acids and organic colloidal materials in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Gaffney, J.S.; Marley, N.A. [Argonne National Lab., IL (United States); Clark, S.B. [Univ. of Georgia, Aiken, SC (United States)

    1996-04-01

    Humic substances are ubiquitous in the environment, occurring in all soils, waters, and sediments of the ecosphere. Humic substances arise from the decomposition of plant and animal tissues yet are more stable than their precursors. Their size, molecular weight, elemental composition, structure, and the number and position of functional groups vary, depending on the origin and age of the material. Humic and fulvic substances have been studied extensively for more than 200 years; however, much remains unknown regarding their structure and properties. Humic substances are those organic compounds found in the environment that cannot be classified as any other chemical class of compounds. They are traditionally defined according to their solubilities. Fulvic acids are those organic materials that are soluble in water at all pH values. Humic acids are those materials that are insoluble at acidic pH values (pH < 2) but are soluble at higher pH values. Humin is the fraction of natural organic materials that is insoluble in water at all pH values. These definitions reflect the traditional methods for separating the different fractions from the original mixture. The humic content of soils varies from 0 to almost 10%. In surface waters, the humic content, expressed as dissolved organic carbon (DOC), varies from 0.1 to 50 ppm in dark-water swamps. In ocean waters, the DOC varies from 0.5 to 1.2 ppm at the surface, and the DOC in samples from deep groundwaters varies from 0.1 to 10 ppm. In addition, about 10% of the DOC in surface waters is found in suspended matter, either as organic or organically coated inorganic particulates. Humic materials function as surfactants, with the ability to bind both hydrophobic and hydrophyllic materials, making numic and fluvic materials effective agents in transporting both organic and inorganic contaminants in the environment.

  12. Fuel cells seminar

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-01

    This year`s meeting highlights the fact that fuel cells for both stationary and transportation applications have reached the dawn of commercialization. Sales of stationary fuel cells have grown steadily over the past 2 years. Phosphoric acid fuel cell buses have been demonstrated in urban areas. Proton-exchange membrane fuel cells are on the verge of revolutionizing the transportation industry. These activities and many more are discussed during this seminar, which provides a forum for people from the international fuel cell community engaged in a wide spectrum of fuel cell activities. Discussions addressing R&D of fuel cell technologies, manufacturing and marketing of fuel cells, and experiences of fuel cell users took place through oral and poster presentations. For the first time, the seminar included commercial exhibits, further evidence that commercial fuel cell technology has arrived. A total of 205 papers is included in this volume.

  13. Preparation for Retirement Seminar

    CERN Multimedia

    HR Department

    2007-01-01

    The Department of Human Resources is organising a preparation for retirement seminar which will take place on the four successive afternoons of 2 to 5 October 2007. Similar seminars in the past have always proved highly successful. Retirement marks the end of one’s working life and the start of a new period of life. This period of transition and change is experienced differently from one individual to another. In any case, being well-informed and prepared greatly facilitates the change in lifestyle. We would like to draw your attention to the following information: Staff concerned: All staff members aged 58 and above as well as those who have retired during the year have been sent a personal invitation to attend. Spouses are welcome. Staff members below 58 who are interested in attending the seminar may also apply. Their applications will be accepted subject to availability of places. Registration: In view of the number of people concerned and the limited capacity of th...

  14. Preparation for Retirement Seminar

    CERN Multimedia

    HR Department

    2011-01-01

    The Human Resources Department is organizing a Preparation for Retirement Seminar, which will take place on 18 and 21 October 2011 in the afternoon in the Main Auditorium and on 19 October and 15 and 16 November 2011 in the afternoon in the Council Chamber. Similar seminars in the past have always proved highly successful. Retirement marks the end of a person’s working life and the start of a new chapter. This period of transition is experienced differently from one individual to another. In all cases, being well-informed and prepared greatly facilitates the change in lifestyle. We would like to draw your attention to the following information: Staff concerned: All staff members aged 58 and above have been sent a personal invitation to attend. Spouses are welcome. Staff members under the age of 58 who are interested in attending the seminar may also apply. Their applications will be accepted subject to availability of places. Registration: In view of the number of people concerned, you are ...

  15. Preparation for retirement seminar

    CERN Multimedia

    HR Department

      The Human Resources Department is organizing a preparation for retirement seminar, which will take place on the afternoons of the 25 and 27 November 2009. Similar seminars in the past have always proved highly successful. Retirement marks the end of a person’s working life and the start of a new chapter. This period of transition is experienced differently from one individual to another. In all cases, being well-informed and prepared greatly facilitates the change in lifestyle. We would like to draw your attention to the following information: Staff concerned: All staff members aged 58 and above have been sent a personal invitation to attend. Spouses are welcome. Staff members under the age of 58 who are interested in attending the seminar may also apply. Their applications will be accepted subject to the availability of places. Registration: In view of the number of people concerned and the limited capacity of the Main Auditorium, you are requested to register in advance via Indico. &a...

  16. Preparation for Retirement Seminar

    CERN Multimedia

    HR Department

    2011-01-01

    The Human Resources Department is organizing a Preparation for Retirement Seminar, which will take place on 18 and 21 October 2011 in the afternoon in the Main Auditorium and on 19 October and 15 and 16 November 2011 in the afternoon in the Council Chamber. Similar seminars in the past have always proved highly successful. Retirement marks the end of a person’s working life and the start of a new chapter. This period of transition is experienced differently from one individual to another. In all cases, being well-informed and prepared greatly facilitates the change in lifestyle. We would like to draw your attention to the following information: Staff concerned: All staff members aged 58 and above have been sent a personal invitation to attend. Spouses are welcome. Staff members under the age of 58 who are interested in attending the seminar may also apply. Their applications will be accepted subject to availability of places. Registration: In view of the number of people concerned, you are r...

  17. TECHNICAL TRAINING SEMINAR

    CERN Multimedia

    Davide VITÈ

    2002-01-01

    Wednesday 6 March   from 9:30 to 16:45 - IT Auditorium - bldg. 31 3-004 Analog Devices DSP Day Thorsten Kistler (Application Engineer), Steffen Boerner (Product Specialist) / ANALOG DEVICES Munich Trying to meet your design challenges, Analog Devices compiles application information and offers chipsets, software, reference designs and mixed-signal, application specific DSPs, for a range of real-time signal processing applications. This seminar will present the latest 16bit fixed-point and 32bit floating-point DSPs (roadmaps; internal architectures, blocks, features benchmarks), with their software, development kits and emulators: Fixed-Point DSP-Family, ADSP-218x and ADSP-219x Blackfin DSP SHARC-Family, 2106x and 2116x TigerSHARC Industrial Contact: François Caloz, Sasco-Spoerle GmbH Language: English Free seminar, no registration Organiser: Davide Vitè / HR-TD / 75141 Davide.Vite@cern.ch Please read the full information on the Technical Training Seminars pages here or con...

  18. TECHNICAL TRAINING SEMINAR

    CERN Multimedia

    Davide Vitè

    2002-01-01

    Wednesday 6 March from 9:30 to 16:45 - IT Auditorium - bldg. 31 3-004 Analog Devices DSP Day Thorsten Kistler (Application Engineer), Steffen Boerner (Product Specialist) / ANALOG DEVICES Munich Trying to meet your design challenges, Analog Devices compiles application information and offers chipsets, software, reference designs and mixed-signal, application specific DSPs, for a range of real-time signal processing applications. This seminar will present the latest 16bit fixed-point and 32bit floating-point DSPs (roadmaps; internal architectures, blocks, features benchmarks), with their software, development kits and emulators: Fixed-Point DSP-Family, ADSP-218x and ADSP-219x Blackfin DSP SHARC-Family, 2106x and 2116x TigerSHARC Industrial Contact: François Caloz, Sasco-Spoerle GmbH Language: English Free seminar, no registration Organiser: Davide Vitè / HR-TD / 75141 Davide.Vite@cern.ch Please read the full information on the Technical Training Seminars pages here or contact the organiser.

  19. Estoque de carbono e quantificação de substâncias húmicas em Latossolo submetido a aplicação contínua de lodo de esgoto Organic carbon stock and quantification of humic substances of an oxisol under continuous sewage sludge application

    Directory of Open Access Journals (Sweden)

    Bruno de Oliveira Dias

    2007-08-01

    . The following accumulated SS doses (dry base were tested: 0, 30, 60, 120, and 240 Mg ha-1 and the treatments were: control without SS addition(L0; SS application to supply one (L1, two (L2, four (L4 and eight (L8 times the N corn requirement. Carbon contents and stocks were evaluated in the soil layers 0-10, 10-20, 20-40 and 40-60 cm, and the C associated to humic substances 0-10 cm deep. As the SS applications increased, the C content and stock rose in the 0-20 cm soil layer. Most soil C (50-66 % is associated to the humin pool, followed by fulvic acid fraction-C and then humic acid fraction-C. Sewage sludge applications result in higher contents of C-humic substances in soil, though the proportion of mineralized C in soil humus remained unchanged.

  20. Humic substances isolated from residues of sugar cane industry as root growth promoter Substâncias húmicas isoladas de resíduos da indústria da cana-de-açúcar como promotoras de crescimento radicular

    Directory of Open Access Journals (Sweden)

    Jader Galba Busato

    2010-04-01

    Full Text Available Plant growth promoting substances are widely used in modern agriculture. Several products in the market are humic substances isolated from different sources. The filter cake, a residue of sugar production, is a rich and renewable source of organic matter and these characteristics place the filter cake as a possible source of plant growth promoting substances. Humic acids (HA from filter cake were characterized, and their effects as root growth promoters were evaluated. Chemical features of the HA were evaluated through elemental composition, acidic functional groups, E4/E6 ratio and infrared spectroscopy analyzes. The biological activity of the HA was assessed using root architecture parameters and the P-type H+-ATPase activity. The lateral root development was directly related to the stimulation of plasma membrane ATPase activity. The ability of HA to promote root development indicate that HA from filter cake can be used as environmental plant growth stimulators.Substâncias promotoras do crescimento vegetal são amplamente utilizadas na agricultura moderna. Existem vários produtos no mercado, muitos dos quais são substâncias húmicas isoladas de diferentes fontes. A torta de filtro, um resíduo da produção do açúcar, é uma fonte rica e renovável de matéria orgânica e essas características a tornam uma possível fonte de substâncias promotoras do crescimento vegetal. Ácidos húmicos (AH da torta de filtro foram caracterizados, e foi avaliado seu efeito como promotor de crescimento radicular. As características químicas dos AH foram avaliadas por meio da composição elementar, grupos funcionais ácidos, relação E4/E6 e espectroscopia de infravermelho. A atividade biológica dos AH foi acessada avaliando-se a arquitetura radicular e a atividade da H+-ATPase de membrana plasmática. O desenvolvimento de raízes laterais foi diretamente relacionado ao estímulo da atividade da H+-ATPase. A habilidade dos AH em promover o

  1. Interaction of humic acids and humic-acid-like polymers with herpes simplex virus type 1

    Science.gov (United States)

    Klöcking, Renate; Helbig, Björn

    The study was performed in order to compare the antiviral activity against herpes simplex virus type 1 (HSV-1) of synthetic humic-acid-like polymers to that of their low-molecular-weight basic compounds and naturally occurring humic acids (HA) in vitro. HA from peat water showed a moderate antiviral activity at a minimum effective concentration (MEC) of 20 µg/ml. HA-like polymers, i.e. the oxidation products of caffeic acid (KOP), hydrocaffeic acid (HYKOP), chlorogenic acid (CHOP), 3,4-dihydroxyphenylacetic acid (3,4-DHPOP), nordihydroguaretic acid (NOROP), gentisinic acid (GENOP), pyrogallol (PYROP) and gallic acid (GALOP), generally inhibit virus multiplication, although with different potency and selectivity. Of the substances tested, GENOP, KOP, 3,4-DHPOP and HYKOP with MEC values in the range of 2 to 10 µg/ml, proved to be the most potent HSV-1 inhibitors. Despite its lower antiviral potency (MEC 40 µg/ml), CHOP has a remarkable selectivity due to the high concentration of this polymer that is tolerated by the host cells (>640 µg/ml). As a rule, the antiviral activity of the synthetic compounds was restricted to the polymers and was not preformed in the low-molecular-weight basic compounds. This finding speaks in favour of the formation of antivirally active structures during the oxidative polymerization of phenolic compounds and, indirectly, of corresponding structural parts in different HA-type substances.

  2. Effect of soil fulvic and humic acid on binding of Pb to goethite–water interface: Linear additivity and volume fractions of HS in the Stern layer

    NARCIS (Netherlands)

    Xiong, J.; Koopal, L.K.; Weng, L.; Wang, J.; Tan, W.

    2015-01-01

    The effects of soil fulvic (JGFA) and humic acid (JGHA) on Pb binding to goethite were investigated with batch experiments and modeling. The CD-MUSIC and NICA-Donnan model could describe the Pb binding to, respectively, the binary Pb–goethite and Pb–HS systems. The adsorption of humic substances

  3. Efeito de substâncias húmicas na cinética de absorção de potássio, crescimento de plantas e concentração de nutrientes em Phaseolus vulgaris L. Effect of humic-like substances on potassium uptake kinetics, plant growth and nutrient concentration in Phaseolus vulgaris L.

    Directory of Open Access Journals (Sweden)

    Carla Machado da Rosa

    2009-08-01

    Full Text Available As substâncias húmicas podem influenciar direta ou indiretamente o metabolismo das plantas, alterando assim o seu crescimento. O objetivo deste trabalho foi avaliar o efeito de substâncias húmicas (SH no crescimento e na concentração de nutrientes em plantas de feijão (Phaseolus vulgaris, L. e nos parâmetros cinéticos de absorção de K. O experimento foi realizado em bancada de laboratório, com luz artificial. As plantas cresceram em vasos contendo solução nutritiva completa acrescida de cinco doses (0; 2,5; 5; 10; e 20 mg L-1 de C de SH solúveis em meio alcalino (ácido húmico + ácido fúlvico, extraídos de amostra de carvão mineral da mina de Candiota, RS, da Companhia Riograndense de Mineração, num delineamento completamente ao acaso, com três repetições. Aos 28 dias de cultivo, foram avaliados parâmetros cinéticos de absorção de K, massa da parte aérea e da raiz seca, teores de N, P, K, Ca e Mg no tecido da parte área e as características morfológicas de raízes (comprimento, área e raio. Os resultados evidenciaram que a adição de SH extraída de carvão mineral estimulou o crescimento do feijão e afetou a cinética de absorção de K. A produção de massa da parte aérea seca das plantas mostrou resposta quadrática à adição de substâncias húmicas, atingindo valor máximo na dose equivalente a 11 mg L-1 de C, enquanto a massa das raízes secas aumentou linearmente em até 41 %, com as doses testadas. As características morfológicas de raiz e o estado nutricional das plantas não foram significativamente afetados pelas SH. Os parâmetros cinéticos de absorção de K, Imáx, Cmín e Km, decresceram linearmente com o aumento das doses de SH, causando redução na taxa de absorção de K nas concentrações deste nutriente na solução superiores a 10 μmol L-1.Humic substances can influence plant metabolism direct or indirectly, thus modifying its growth. The objective of this study was to evaluate

  4. Arbejdspapir til Thesis-seminar

    DEFF Research Database (Denmark)

    Damkjaer, Maja Sonne

    2014-01-01

    Arbejdspapir til Thesis-seminar afholdt ved Forskningsseminar i Forskningsprogrammet: Medier, Kommunikation og Samfund, Institut for Æstetik og Kommunikation, Aarhus Universitet. Afhandlingens teoretiske afsnit.......Arbejdspapir til Thesis-seminar afholdt ved Forskningsseminar i Forskningsprogrammet: Medier, Kommunikation og Samfund, Institut for Æstetik og Kommunikation, Aarhus Universitet. Afhandlingens teoretiske afsnit....

  5. Parenting Seminars for Divorcing Parents.

    Science.gov (United States)

    Frieman, Barry B.

    1995-01-01

    Profiles the parenting seminars and counseling services for divorcing parents offered by the Children of Separation and Divorce Center, a community service agency in Maryland. The seminars are designed to help parents adjust to divorce and understand the needs of their children during and after the divorce process. (MDM)

  6. Debating Technologies (Dagstuhl Seminar 15512)

    OpenAIRE

    Gurevych, Iryna; Hovy, Eduard H.; Slonim, Noam; Stein, Benno

    2016-01-01

    This report documents the program and the outcomes of Dagstuhl Seminar 15512 "Debating Technologies". The seminar brought together leading researchers from computational linguistics, information retrieval, semantic web, and database communities to discuss the possibilities, implications, and necessary actions for the establishment of a new interdisciplinary research community around debating technologies. 31 participants from 22 different institutions took part in sixteen sessions that includ...

  7. Algorithms seminars 1992-1993

    OpenAIRE

    Salvy, Bruno

    1993-01-01

    These seminar notes represent the proceedings (some in French) of a seminar devoted to the analysis of algorithms and related topics. The subjects covered include combinatorial models and random generation, symbolic computation, asymptotic analysis, average-case analysis of algorithms and data structures and some computational number theory.

  8. Seminar series on Safety matters

    CERN Multimedia

    HSE

    2010-01-01

    The HSE - Occupational Health & Safety and Environmental Protection - Unit is starting a seminar series on Safety matters. The aim is to invite colleagues from Universities, Industries or Government Agencies to share their experience. The seminars will take place in intervals of several months. Part of the Seminars will be held in the form of a Forum where participants can discuss and share views with persons who manage, teach or research Safety matters elsewhere. You are invited to the first Safety Seminar on 22nd September 2010 at 10h00 in building 40 S2 A1 "Salle Andersson" L’Ecole Polytechnique Fédérale de Lausanne (EPFL) will present the way safety is managed in their research institution. Some aspects of research in physics and chemical laboratories will also be presented. The seminar will be given by Dr Thierry Meyer, Head of OHS at FSB-EPFL and Dr Amela Groso, responsible for the safety of the physics institutes

  9. Interaction between humic acids and anthraquinone dyes

    Energy Technology Data Exchange (ETDEWEB)

    Shinozuka, N.; Lee, C. (The University of Tokyo, Tokyo (Japan). Institute of Industrial Science)

    1991-08-20

    Interactions between humic acids and anthraquinone disperse-dyes were studied. A humic acid extracted from a marine sediment and a commercial one were used to solubilized dyes sparingly soluble in water. The dye solubility in humic acid solution increases with humic acid concentration and enhancement was marked for solution of Aldrich humic acid. The addition of salts decreased the solubility of the dye. But the effects were complicated. Dye solubility increased with temperature. Especially, in the case of a 0.1% solution of marine humic acid at high temperature, the solubility increased. The spectrum of the dye were changed by solubilization in humic acid solution, and a twin peak characteristics of 1,4-isomers of polyaminoanthraquinone disappeared and a broad peak appeared. The dye solubilized by humic acid may thus possibly exist as a solid state as a deposit on quartz. 23 refs., 3 figs., 3 tabs.

  10. Substâncias húmicas e suas relações com o grau de subsidência em Organossolos de diferentes ambientes de formação no Brasil Humic substances and their relationship to the degree of subsidence of histosols in different formation environments in Brazil

    Directory of Open Access Journals (Sweden)

    Adierson Gilvani Ebeling

    2013-06-01

    of organic compounds. The objective of this study was to quantify and assess the distribution of humic fractions in histosols in different environments and regions of Brazil, relating them to the processes of subsidence. The carbon (C content in humic substances indicated a predominance of C from the humic-acid fraction (HAF-C of 22.1g kg-1 to 153.7g kg-1 in soils from high altitude mountainous regions and upland areas. Possibly the colder climate, coupled with improved fertility, favored the formation of this fraction at the expense of the fulvic acid and humin fractions. On the other hand, the higher humic-acid content makes organosols in these environments more susceptible to the processes of subsidence, especially when under agricultural management. Whereas in flood and coastal-plain environments, there was a greater formation of C from the humin fraction (HUM-C from 79.2 to 267.2g kg-1, being the fraction of humic substances most resistant to decomposition. The sum of the humic fractions represented 89% of the total carbon, these two variables being highly correlated. The relationship between alkaline extract and humin (AE / HUM groups classes of histosols by their formation environment, and is suggested as a diagnostic attribute at the lower levels of the Brazilian System for Soil Classification (SiBCS, allowing differentiation of the histosols as to their potential for subsidence.

  11. Preparation for retirement seminar

    CERN Multimedia

    HR Department

    2010-01-01

    (Health insurance and wealth and succession planning) During the preparation for retirement seminar in November 2009, the sessions on health insurance in Switzerland and in France unfortunately had to be postponed. Participants in the seminar also expressed interest in an information session on “How to manage your wealth and organize your succession”. The sessions on health insurance will be held on 16 March 2010 and those on managing wealth and succession on 18 March 2010. Programme for Tuesday 16 March 2010 (TH Theory Conference Room, Building 4/3-006): 09:00 Health insurance in Switzerland by Mr. Sandro Breitenstein, Service de l'Assurance Maladie du Canton de Genève 10:00 Coffee break 10:20 Health insurance in France by Mr. Dominique Curtiaud, Caisse Primaire d'Assurance Maladie de l'Ain Programme for Thursday 18 March 2010 (TH Theory Conference Room, Building 4/3-006): 09:00 How to manage your wealth and organize your succession in Switzerland by Mr. Jean-Marc W...

  12. Technical Training Seminar

    CERN Multimedia

    2003-01-01

    Thursday 4 September From 14:00 to 17:00 - Training Centre Auditorium bldg. 593, room 11 The Summit Design VisualElite 4.0 Release Jean Marie St Paul / SUMMIT DESIGN, Europe, Technical Manager Michel Delcroix / SUMMIT DESIGN, Southern Europe, Sales F-95015 CERGY PONTOISE, France Summit Design is an important EDA digital hardware design tool supplier, and the industry leader in the emerging Electronic System Level design domain. Its VisualElite program has been used at CERN for several years. This seminar will include the highlights of the program's latest release. It will be illustrated how Summit Design products can provide a high-level C/C++ and SystemC functional modelling design and verification environment, enabling engineers to analyse system concepts before the implementation stage. The seminar will show how mixed SystemC and HDL simulation can be done, along with solutions for hardware/software development. • HDL new features: Connectivity Table Editor. Xemacs full integration. New NCsi...

  13. Technical Training Seminar

    CERN Multimedia

    2003-01-01

    Thursday 4 September From 14:00 to 17:00 - Training Centre Auditorium bldg. 593, room 11 The Summit Design VisualElite 4.0 Release Jean Marie St Paul / SUMMIT DESIGN, Europe, Technical Manager Michel Delcroix / SUMMIT DESIGN, Southern Europe, Sales F-95015 CERGY PONTOISE, France Summit Design is an important EDA digital hardware design tool supplier, and the industry leader in the emerging Electronic System Level design domain. Its VisualElite program has been used at CERN for several years. This seminar will include the highlights of the program's latest release. It will be illustrated how Summit Design products can provide a high-level C/C++ and SystemC functional modelling design and verification environment, enabling engineers to analyse system concepts before the implementation stage. The seminar will show how mixed SystemC and HDL simulation can be done, along with solutions for hardware/software development. • HDL new features: Connectivity Table Editor. Xemacs full integration. New NCsim ...

  14. Effects of heating on composition, degree of darkness, and stacking nanostructure of soil humic acids.

    Science.gov (United States)

    Katsumi, Naoya; Yonebayashi, Koyo; Okazaki, Masanori

    2016-01-15

    Wildfires and prescribed burning can affect both the quality and the quantity of organic matter in soils. In this study, we investigated qualitative and quantitative changes of soil humic substances in two different soils (an Entisol from a paddy field and an Inceptisol from a cedar forest) under several controlled heating conditions. Soil samples were heated in a muffle furnace at 200, 250, or 300 °C for 1, 3, 5, or 12h. The humic acid and fulvic acid contents of the soil samples prior to and after heating were determined. The degree of darkness, elemental composition, carbon and nitrogen stable isotope ratios, (13)C nuclear magnetic resonance spectra, and X-ray diffraction patterns of humic acids extracted from the soils before and after heating were measured. The proportion of humic acids in total carbon decreased with increasing heating time at high temperature (300 °C), but increased with increasing heating time at ≤ 250 °C. The degree of darkness of the humic acids increased with increasing heating time and temperature. During darkening, the H/C atomic ratios, the proportion of aromatic C, and the carbon and nitrogen stable isotope ratios increased, whereas the proportions of alkyl C and O-alkyl C decreased. X-ray diffraction analysis verified that a stacking nanostructure developed by heating. Changes in the chemical structure of the humic acids from the heated soils depended on the type of soil. The major structural components of the humic acids from the heated Entisol were aromatic C and carboxylic C, whereas aliphatic C, aromatic C, and carboxylic C structural components were found in the humic acids from the heated Inceptisol. These results suggest that the heat-induced changes in the chemical structure of the humic acids depended on the source plant. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. TECHNICAL TRAINING SEMINAR

    CERN Multimedia

    Davide Vitè

    2002-01-01

    Wednesday 22 May From 14:00 to 17:00 - Training Centre Auditorium - bldg. 593, room 11 Reliability, Availability, Maintainability and Safety (RAMS) Philippe Galley, Vincent Brindejonc / LIGERON S.A., Saint Aubin, France This seminar will address Reliability, Availability, Maintainability and Safety (RAMS) engineering concepts to guarantee availability and safety of critical equipments, in particular in a high technology and R&D environment. Applications of these concepts will be presented. 14h00-14h30 Introduction to Reliability, Availability, Maintainability and Safety activities: general introduction to RAMS, basic definitions, integration of RAMS in a large project. 14h40-16h10 RAMS methodologies: Functional Analysis methodologies Preliminary Hazard Analysis Failure Mode Effects and Criticality Analysis (FMECA) Fault Tree Analysis Use of standards for Reliability predictions Reliability Block Diagrams for a system Advanced models, e.g. Markov's Graphs 16h30-17h00 Presentation of the activ...

  16. TECHNICAL TRAINING SEMINAR

    CERN Multimedia

    Davide Vitè

    2002-01-01

    Wednesday 15 May 14:00 to 16:00 - Training Centre Auditorium - bldg. 593, room 11 Testing Embedded Software and Systems Ian Smith / SEVEN LAYER COMMUNICATIONS LTD, Edinburgh, Scotland The growing use of embedded processors has resulted in considerable challenges for software and system developers, to ensure that the products they produce function as required, without error. The increasing complexity of these products, and the systems they operate in, adds to the difficulty in testing these products effectively. These challenges will apply to the development of equipment and software for use on the LHC project. This seminar is aimed at anyone involved in the development and/or in the verification of embedded hardware, software or systems at CERN. It will provide an introduction to testing embedded products, and some insights into ways to address the growing complexity of modern embedded products. It will also show some of the methods Seven Layer Communications Ltd. have applied in developing effective test fac...

  17. EUROTHERM Seminar No. 17

    CERN Document Server

    Lockwood, F; Taine, J

    1991-01-01

    This volume contains the selected papers presented at the EUROTHERM SEMINAR No. 17 - Heat Transfer in Radiating and Combusting Systems held at Cascais from October 8th- 10th, 1990. The EUROTHERM COMMITTEE was created by representatives of the member countries of the European Communities for the organization and coordination of European Scientific events in the field of thermal sciences and their applications. The book is focused on the integration of the heat transfer and combustion. These two subjects have traditionally been considered separate disciplines. In reality, the two are closely interwoven. The central purpose of the book is to generate an effective cross fertilisation of the two at both the fundamental and applied levels. The book reports on: mathematical simulations of heat transfer in reacting systems, new measurements of and measurement techniques for the radiation properties of the intervening medium, and data and theoretical analyses which clarify the physical nature of the complex interactio...

  18. Growth of silver catfish ( Rhamdia quelen exposed to acidic pH at different humic acid levels

    Directory of Open Access Journals (Sweden)

    Silvio Teixeira da Costa

    2016-06-01

    Full Text Available ABSTRACT: Humic substances are organic compounds that possess high molecular weight and are formed by the decomposition of plant materials. Humic substances comprise humic acids, fulvic acids and humin. Humic acids (HA have shown to be able to provide some protection to biological membranes of fish in water with low pH, replacing the protective action of Ca2+. Thus, this studyaimed to observe growth of silver catfish ( Rhamdia quelen juveniles exposed to pHs 5.5 and 6.5 and to different levels of HA: 0, 10, 25 and 50mg L-1. Results showed that, irrespective of pH, HA was highly detrimental to silver catfish growth, since the higher the concentration of HA, the lower the weight gain and feed intake, resulting in lower biomass and lower specific growth rate of juveniles. Hence, HA is extremely damaging to the performance of silver catfish juveniles in the tested concentrations.

  19. Electromagnetic Simulation Seminar and Opera/Tosca update Seminar

    CERN Multimedia

    IT Department

    2012-01-01

    9 May 2012 Kjell Johnsen Auditorium – Room 30-7-018 Electromagnetic Simulation Seminar & Opera/Tosca update Seminar By Cobham Technical Services – Vector Fields Software Virtual prototyping using electromagnetic simulation software plays an important role in the design stage of many devices and the Opera software has been in use for this purpose at CERN for over a decade. A technical seminar will take place concerning the latest developments in electromagnetic design, analysis and multi-physics applications for large scientific experiments.  Information will be presented on applications such as superconducting magnets and ion-beam sources. The seminar will be presented by engineers/physicists from Cobham Technical Services – Vector Fields Software who develop the Opera program.  It is FREE to attend and is open to both current Opera software users and also those who wish to expand their knowledge and understand better the capabilities on offer. Prog...

  20. Ultrafiltration technique in conjunction with competing ligand exchange method for Ni–humics speciation in aquatic environment

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, P.; Boissel, M.; Reuillon, A.; Babu, P.V.R.; Parthiban, G.

    much attention in recent years since the fate and transport of trace metals are found to be partially controlled by the size/molecular weight of dissolved organics [7-9]. Humic substances (mainly composed by humic and fulvic acid), predominant... attraction) and these aggregates are able to disaggregate/reaggregate, depending on the nature and concentration of humics and pH of the medium [12–16]. The stability, lability and mobility of metal-humate complexes in natural environments are dependent...

  1. [Effects of different managements on soil humic acid structural features in chestnut soil on typical Leymus chinensis steppe, Inner Mongolia, China].

    Science.gov (United States)

    Li, Guang-Jun; Lü, Yi-Zhong; Li, Bao-Guo

    2009-06-01

    Grazing has a lot of effects on grassland soil properties. The objective of the present study is to investigate the effects of different managements on soil humic acids. Soil samples were collected from the surface soil of four adjacent plots ( I , II , III and IV) at a long-term experiment site of the Inner Mongolia Grassland Ecosystem Research Station (IMGERS), the Chinese Academy of Sciences. The structure features of humic acids were investigated by cross-polarization magic angle spinning 13C-nuclear magnetic resonance spectroscopy (CP/MAS 13C-NMR), FTIR and elemental analysis. The results indicated that the humic acid extracted from the grazing plots were characterized by a higher degree of humification, including loss of polysaccharides, decrease in lignin content and increase in aromaticity. Compared with the humic substances from the grazing plots, the humic substances from fenced plots showed a lower degree of humification and were considerably more aliphatic in nature.

  2. Effects of heating on composition, degree of darkness, and stacking nanostructure of soil humic acids

    Energy Technology Data Exchange (ETDEWEB)

    Katsumi, Naoya, E-mail: n-katsu@ishikawa-pu.ac.jp; Yonebayashi, Koyo; Okazaki, Masanori

    2016-01-15

    Wildfires and prescribed burning can affect both the quality and the quantity of organic matter in soils. In this study, we investigated qualitative and quantitative changes of soil humic substances in two different soils (an Entisol from a paddy field and an Inceptisol from a cedar forest) under several controlled heating conditions. Soil samples were heated in a muffle furnace at 200, 250, or 300 °C for 1, 3, 5, or 12 h. The humic acid and fulvic acid contents of the soil samples prior to and after heating were determined. The degree of darkness, elemental composition, carbon and nitrogen stable isotope ratios, {sup 13}C nuclear magnetic resonance spectra, and X-ray diffraction patterns of humic acids extracted from the soils before and after heating were measured. The proportion of humic acids in total carbon decreased with increasing heating time at high temperature (300 °C), but increased with increasing heating time at ≤ 250 °C. The degree of darkness of the humic acids increased with increasing heating time and temperature. During darkening, the H/C atomic ratios, the proportion of aromatic C, and the carbon and nitrogen stable isotope ratios increased, whereas the proportions of alkyl C and O-alkyl C decreased. X-ray diffraction analysis verified that a stacking nanostructure developed by heating. Changes in the chemical structure of the humic acids from the heated soils depended on the type of soil. The major structural components of the humic acids from the heated Entisol were aromatic C and carboxylic C, whereas aliphatic C, aromatic C, and carboxylic C structural components were found in the humic acids from the heated Inceptisol. These results suggest that the heat-induced changes in the chemical structure of the humic acids depended on the source plant. - Highlights: • Darkness of humic acids increased with increasing heating time and temperature. • Aromatic carbon content increased during darkening. • Carbon and nitrogen stable isotope

  3. Immersive Analytics (Dagstuhl Seminar 16231)

    OpenAIRE

    Dwyer, Tim; Henry Riche, Nathalie; Klein, Karsten; Stuerzlinger, Wolfgang; Thomas, Bruce

    2016-01-01

    This report documents the program and the outcomes of Dagstuhl Seminar 16231 "Immersive Analytics". Close to 40 researchers and practitioners participated in this seminar to discuss and define the field of Immersive Analytics, to create a community around it, and to identify its research challenges. As the participants had a diverse background in a variety of disciplines, including Human-Computer-Interaction, Augmented and Virtual Reality, Information Visualization, and Visual Analytics, the ...

  4. Bioactivity of chemically transformed humic matter from vermicompost on plant root growth.

    Science.gov (United States)

    Dobbss, Leonardo Barros; Pasqualoto Canellas, Luciano; Lopes Olivares, Fábio; Oliveira Aguiar, Natália; Peres, Lázaro Eustáquio Pereira; Azevedo, Mariana; Spaccini, Riccardo; Piccolo, Alessandro; Façanha, Arnoldo R

    2010-03-24

    Chemical reactions (hydrolysis, oxidation, reduction, methylation, alkyl compounds detachment) were applied to modify the structure of humic substances (HS) isolated from vermicompost. Structural and conformational changes of these humic derivatives were assessed by elemental analyses, size exclusion chromatography (HPSEC), solid-state nuclear magnetic resonance ((13)C CPMAS-NMR), and diffusion ordered spectroscopy (DOSY-NMR), whereas their bioactivity was evaluated by changes in root architecture and proton pump activation of tomato and maize. All humic derivatives exhibited a large bioactivity compared to original HS, both KMnO(4)-oxidized and methylated materials being the most effective. Whereas no general relationship was found between bioactivity and humic molecular sizes, the hydrophobicity index was significantly related with proton pump stimulation. It is suggested that the hydrophobic domain can preserve bioactive molecules such as auxins in the humic matter. In contact with root-exuded organic acids the hydrophobic weak forces could be disrupted, releasing bioactive compounds from humic aggregates. These findings were further supported by the fact that HS and all derivatives used in this study activated the auxin synthetic reporter DR5::GUS.

  5. Formation of aryl-chlorinated aromatic acids and precursors for chloroform in chlorination of humic acid

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Leer, E.W.B. de; Galan, L.

    1985-01-01

    The formation of chloroform when humic substances are chlorinated is well known. Other chlorinated products that may be formed are chloral, di- and trichloroacetic acid, chlorinated C-4 diacids, and α-chlorinated aliphatic acids. Several of these compounds are formed in molar yields comparable

  6. Measurement of humic and fulvic acid concentrations and dissolution properties by a rapid batch procedure.

    NARCIS (Netherlands)

    Zomeren, van A.; Comans, R.N.J.

    2007-01-01

    Although humic substances (HS) strongly facilitate the transport of metals and hydrophobic organic contaminants in environmental systems, their measurement is hampered by the time-consuming nature of currently available methods for their isolation and purification. We present and apply a new rapid

  7. The role of humic and fulvic acids in the phototransformation of phenolic compounds in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Calza, P., E-mail: paola.calza@unito.it; Vione, D.; Minero, C.

    2014-09-15

    Humic substances (HS) are known to act as photosensitizers toward the transformation of pollutants in the surface layer of natural waters. This study focused on the role played by HS toward the transformation of xenobiotics in seawater, with the purpose of assessing the prevailing degradation routes. Phenol was chosen as model xenobiotic and its transformation was investigated under simulated sunlight in the presence of terrestrial or marine humic and fulvic acids, in pure water at pH 8, artificial seawater (ASW) or natural seawater (NSW). The following parameters were determined: (1) the phenol degradation rate; (2) the variation in HS concentration with irradiation time; (3) the production of transformation products; (4) the influence of iron species on the transformation process. Faster transformation of phenol was observed with humic acids (HA) compared to fulvic acids (SRFA), and transformation induced by both HA and SRFA was faster in ASW than that in pure water. These observations can be explained by assuming an interplay between different competing and sometimes opposite processes, including the competition between chloride, bromide and dissolved oxygen for reaction with HS triplet states. The analysis of intermediates formed in the different matrices under study showed the formation of several hydroxylated (hydroquinone, 1,4-benzoquinone, resorcinol) and condensed compounds (2,2′-bisphenol, 4,4′-bisphenol, 4-phenoxyphenol). Although 1,4-benzoquinone was the main transformation product, formation of condensed molecules was significant with both HA and SRFA. Experiments on natural seawater spiked with HS confirmed the favored formation of condensed products, suggesting a key role of humic matter in dimerization reactions occurring in saline water. - Highlights: • Phenol transformation in seawater can be photosensitized by humic substances. • Dimeric species are peculiar intermediates formed in the process. • Phenol degradation occurred faster with

  8. TECHNICAL TRAINING SEMINAR

    CERN Multimedia

    Davide VITÈ

    2002-01-01

    Wednesday 27 February   from 9:00 to 12:00, LHC Auditorium, bldg. 33 7-018 LabVIEW Real-Time National Instruments, Ennetbaden, Switzerland With LabVIEW Real-Time, you can choose from a variety of RT Series hardware. Add a real-time data acquisition component into a larger measurement and automation system or create a single stand-alone real-time solution with data acquisition, signal conditioning, motion control, RS-232, GPIB instrumentation, and Ethernet connectivity. With the various hardware options, you can create a system to meet your precise needs today, while the modularity of the system means you can add to the solution as your system requirements grow. If you are interested in Reliable and Deterministic systems for Measurement and Automation, you will profit from this seminar. Agenda: Real-Time Overview LabVIEW RT Hardware Platforms - Linux on PXI Programming with LabVIEW RT Real-Time Operating Systems concepts Timing Applications Data Transfer Industrial Contact: Pierre-Andr&ea...

  9. TECHNICAL TRAINING SEMINAR

    CERN Multimedia

    2004-01-01

    Tuesday 3 February 2004 From 09:00 to 13:30 - Training Centre Auditorium - bldg. 593, room 11 USB (Universal Serial Bus) CYPRESS Seminar Claudia Colombini, Field Application Engineer CYPRESS ActiveComp Electronic GmbH D-85077 MANCHING, Germany As a pioneer in USB, CYPRESS sets the standard for cost-effective solutions without sacrificing functionality, performance or reliability. Having shipped over 200 million USB devices, Cypress is the undisputed market leader and demonstrate unmatched USB expertise. With the industry's broadest selection of USB solutions, Cypress has the right silicon, software and support for every USB application, from Low-speed to High-Speed and USB On-The-Go (OTG). • 9:00 - 10:30 Overview of USB systems. USB CYPRESS product overview. Peripherals: Low Speed, Full Speed, High Speed (1.1 and 2.0). Hub Solutions, Embedded Host Solutions, On-The-Go (OTG) and wireless USB. USB Development Tools (first part) • 10:30 - 10:45 coffee • 10:45 - 13:00 (second part)...

  10. TECHNICAL TRAINING SEMINAR

    CERN Multimedia

    2004-01-01

    Tuesday 3 February 2004 From 09:00 to 13:30 - Training Centre Auditorium - bldg. 593, room 11 USB (Universal Serial Bus) CYPRESS Seminar Claudia Colombini, Field Application Engineer CYPRESS ActiveComp Electronic GmbH D-85077 MANCHING, Germany As a pioneer in USB, CYPRESS sets the standard for cost-effective solutions without sacrificing functionality, performance or reliability. Having shipped over 200 million USB devices, Cypress is the undisputed market leader and demonstrate unmatched USB expertise. With the industry's broadest selection of USB solutions, Cypress has the right silicon, software and support for every USB application, from Low-speed to High-Speed and USB On-The-Go (OTG). • 09:00 - 10:30 Overview of USB systems. USB CYPRESS product overview. Peripherals: Low Speed, Full Speed, High Speed (1.1 and 2.0). Hub Solutions, Embedded Host Solutions, On-The-Go (OTG) and wireless USB. USB Development Tools (first part) • 10:30 - 10:45 coffee • 10:45 - 13:00 (second part)...

  11. TECHNICAL TRAINING SPECIAL SEMINAR

    CERN Multimedia

    Technical Training; Tel. 74924

    2001-01-01

    Wednesday 21 November From 9:00 hrs - bldg. 593 R-010 Linear Design Seminar James Bryant, Eberhard Brunner / ANALOG DEVICES Munich James Bryant, one of the well-known Analog Devices speakers, will present the reasons to use components based on new design processes. Among industrial and high speed applications, a particular focus will be given to single supply and low voltage applications. Eberhard Brunner is the specialist of RF products by Analog Devices. After several years in the US in the component design sector for these products, he will give a tutorial for communication and wireless, and applications based on high speed linear components. 09.00-10.15 Low voltage processes and high precision design techniques; AC and DC signal handling with low voltage and high speed products. 10.30-12.15 How to optimise high speed single supply applications; Single supply products in precision applications; Digital isolation, decoupling and grounding in high speed applications. 13.30-15.15 Communications and wireless, ...

  12. TECHNICAL TRAINING SPECIAL SEMINAR

    CERN Multimedia

    Technical Training; Tel.74924

    2001-01-01

    Wednesday 21 November From 9:00 hrs - Training Centre Auditorium room 11, bldg. 593 Linear Design Seminar James Bryant, Eberhard Brunner / ANALOG DEVICES Munich James Bryant, one of the well-known Analog Devices speakers, will present the reasons to use components based on new design processes. Among industrial and high speed applications, a particular focus will be given to single supply and low voltage applications. Eberhard Brunner is the specialist of RF products by Analog Devices. After several years in the US in the component design sector for these products, he will give a tutorial for communication and wireless, and applications based on high speed linear components. 09.00-10.15 Low voltage processes and high precision design techniques; AC and DC signal handling with low voltage and high speed products. 10.30-12.15 How to optimise high speed single supply applications; Single supply products in precision applications; Digital isolation, decoupling and grounding in high speed applications. 13.30-15.15...

  13. Interaction and transport of actinides in natural clay rock with consideration of humic substances and clay organics. Characterization and quantification of the influence of clay organics on the interaction and diffusion of uranium and americium in the clay. Joint project

    Energy Technology Data Exchange (ETDEWEB)

    Bernhard, Gert [Helmholtz-Zentrum Dresden-Rossendorf e.V. (Germany). Inst. of Radiochemistry; Schmeide, Katja; Joseph, Claudia; Sachs, Susanne; Steudtner, Robin; Raditzky, Bianca; Guenther, Alix

    2011-07-01

    The objective of this project was the study of basic interaction processes in the systems actinide - clay organics - aquifer and actinide - natural clay - clay organics - aquifer. Thus, complexation, redox, sorption and diffusion studies were performed. To evaluate the influence of nitrogen, phosphorus and sulfur containing functional groups of humic acid (HA) on the complexation of actinides in comparison to carboxylic groups, the Am(III) and U(VI) complexation by model ligands was studied by UV-Vis spectroscopy and TRLFS. The results show that Am(III) is mainly coordinated via carboxylic groups, however, probably stabilized by nitrogen groups. The U(VI) complexation is dominated by carboxylic groups, whereas nitrogen and sulfur containing groups play a minor role. Phosphorus containing groups may contribute to the U(VI) complexation by HA, however, due to their low concentration in HA they play only a subordinate role compared to carboxylic groups. Applying synthetic HA with varying sulfur contents (0 to 6.9 wt.%), the role of sulfur functionalities of HA for the U(VI) complexation and Np(V) reduction was studied. The results have shown that sulfur functionalities can be involved in U(VI) humate complexation and act as redox-active sites in HA for the Np(V) reduction. However, due to the low content of sulfur in natural HA, its influence is less pronounced. In the presence of carbonate, the U(VI) complexation by HA was studied in the alkaline pH range by means of cryo-TRLFS (-120 C) and ATR FT-IR spectroscopy. The formation of the ternary UO{sub 2}(CO{sub 3}){sub 2}HA(II){sup 4-} complex was detected. The complex formation constant was determined with log {beta}{sub 0.1} M = 24.57 {+-} 0.17. For aqueous U(VI) citrate and oxalate species, luminescence emission properties were determined by cryo-TRLFS and used to determine stability constants. The existing data base could be validated. The U(VI) complexation by lactate, studied in the temperature range 7 to 65 C

  14. [Apply fourier transform infrared spectra coupled with two-dimensional correlation analysis to study the evolution of humic acids during composting].

    Science.gov (United States)

    Bu, Gui-jun; Yu, Jing; Di, Hui-hui; Luo, Shi-jia; Zhou, Da-zhai; Xiao, Qiang

    2015-02-01

    The composition and structure of humic acids formed during composting play an important influence on the quality and mature of compost. In order to explore the composition and evolution mechanism, municipal solid wastes were collected to compost and humic and fulvic acids were obtained from these composted municipal solid wastes. Furthermore, fourier transform infrared spectra and two-dimensional correlation analysis were applied to study the composition and transformation of humic and fulvic acids during composting. The results from fourier transform infrared spectra showed that, the composition of humic acids was complex, and several absorbance peaks were observed at 2917-2924, 2844-2852, 2549, 1662, 1622, 1566, 1454, 1398, 1351, 990-1063, 839 and 711 cm(-1). Compared to humic acids, the composition of fulvci acids was simple, and only three peaks were detected at 1725, 1637 and 990 cm(-1). The appearance of these peaks showed that both humic and fulvic acids comprised the benzene originated from lignin and the polysaccharide. In addition, humic acids comprised a large number of aliphatic and protein which were hardly detected in fulvic acids. Aliphatic, polysaccharide, protein and lignin all were degraded during composting, however, the order of degradation was different between humic and fulvci acids. The result from two-dimensional correlation analysis showed that, organic compounds in humic acids were degraded in the following sequence: aliphatic> protein> polysaccharide and lignin, while that in fulvic acids was as following: protein> polysaccharide and aliphatic. A large number of carboxyl, alcohols and ethers were formed during the degradation process, and the carboxyl was transformed into carbonates. It can be concluded that, fourier transform infrared spectra coupled with two-dimensional correlation analysis not only can analyze the function group composition of humic substances, but also can characterize effectively the degradation sequence of these

  15. Chemistry of metal-humic complexes contained in Megalopolis lignite and potential application in modern organomineral fertilization

    Energy Technology Data Exchange (ETDEWEB)

    Chassapis, Konstantinos; Roulia, Maria; Tsirigoti, Dimitra [Inorganic Chemistry Laboratory, Department of Chemistry, University of Athens, Panepistimiopolis 157 71, Athens (Greece)

    2009-06-01

    Lignite samples from two deposits located in the Megalopolis Basin, Southern Greece, were evaluated for their potential applicability as raw materials for the production of organomineral fertilizers. Fundamental chemical analyses were carried out to demonstrate high humic substances and metal contents. To determine their relative distribution in the Megalopolis lignite extract, eight elements, namely Na, K, Cd, Mn, Mg, Pb, Zn, and Cu, were studied both in H{sub 2}O and in Na{sub 4}P{sub 2}O{sub 7}/NaOH solutions. The behavior of these metals showed significant variations; Zn, Pb, Cd, and Cu associate mostly to the humic substances and proved scarce in the water extract. Contrarily, K and Mg gave a significantly low total yield in the Na{sub 4}P{sub 2}O{sub 7}/NaOH solution, while Mn was classified among the least extracted elements. Further enrichment of Megalopolis humic substances in these metals was achieved; Pb and Mg proved the most and least retained metal, respectively. Decomplexation titration curves of humic matter saturated with these metal ions demonstrated that novel organomineral fertilizing materials may develop based on optimized metal ion and humate contents, which can retain metals in a soluble form within a wide pH range. Formation of complexes between humic substances and Zn, Cd, and Mg was clearly indicated. (author)

  16. Factors Influencing Seminar Learning and Academic Achievement.

    Science.gov (United States)

    Spruijt, Annemarie; Leppink, Jimmie; Wolfhagen, Ineke; Bok, Harold; Mainhard, Tim; Scherpbier, Albert; van Beukelen, Peter; Jaarsma, Debbie

    2015-01-01

    Many veterinary curricula use seminars, interactive educational group formats in which some 25 students discuss questions and issues relating to course themes. To get indications on how to optimize the seminar learning process for students, we aimed to investigate relationships between factors that seem to be important for the seminar learning process, and to determine how these seminar factors account for differences in students' achievement scores. A 57-item seminar evaluation (USEME) questionnaire was administered to students right after they attended a seminar. In total, 80 seminars distributed over years 1, 2, and 3 of an undergraduate veterinary medicine curriculum were sampled and 988 questionnaires were handed in. Principal factor analysis (PFA) was conducted on 410 questionnaires to examine which items could be grouped together as indicators of the same factor, and to determine correlations between the derived factors. Multilevel regression analysis was performed to explore the effects of these seminar factors and students' prior achievement scores on students' achievement scores. Within the questionnaire, four factors were identified that influence the seminar learning process: teacher performance, seminar content, student preparation, and opportunities for interaction within seminars. Strong correlations were found between teacher performance, seminar content, and group interaction. Prior achievement scores and, to a much lesser extent, the seminar factor group interaction appeared to account for differences in students' achievement scores. The factors resulting from the present study and their relation to the method of assessment should be examined further, for example, in an experimental setup.

  17. SOIL POLLUTION OF SELECTED PAHS AS A FACTOR AFFECTING THE PROPERTIES OF HUMIC ACIDS

    OpenAIRE

    Bożena Dębska; Magdalena Banach-Szott; Ewa Rosa

    2014-01-01

    It is well-known that the properties of humus soil substances (including humic acids) are soil-type-specific. However, one shall consider the fact that properties of organic matter of soil can be modified by farming system (crop rotation, fertilisation) as well as other external factors, including pollutants; PAHs. The objective of the paper is to determine the effect of a single-time pollution of soils with high rates of PAHs on the properties of humic acids. The research was performed with ...

  18. The use of total luminescence spectroscopy in the investigation of the effects of different rice management practices on humic substances of a planosol Uso da técnica de luminescência total na investigação dos efeitos de diferentes manejos do solo para arroz sobre as substâncias húmicas de um planossolo

    Directory of Open Access Journals (Sweden)

    Rodrigo Nogueira Olendzki

    2009-10-01

    Full Text Available In the Earth's carbon cycle, C stocks in the soil are higher than in vegetation and atmosphere. Maintaining and conserving organic C concentrations in the soil by specific management practices can improve soil fertility and productivity. The aim of this study was to evaluate the impact of agricultural management techniques and influence of water regime (flooded or drained on the structure of humic substances by excitation/emission matrix fluorescence. Six samples of a Planosol (Planossolo by the Brazilian System of Soil Classification were collected from a rice field. Humic substances (HS were extracted from flooded and drained soil under different agricultural management techniques: conventional tillage, reduced tillage and grassland. Two peaks at a long emission wavelength were observed in the EEM spectra of HA whereas those of the corresponding FA contained a unique fluorophore at an intermediate excitation/emission wavelength pair (EEWP value. The fluorescence intensity measured by total luminescence (FI TL of HA was lower than that of the corresponding FA. A comparison of all samples (i.e., the HA values compared to each other revealed only slight differences in the EEWP position, but the FI TL values were significantly different. In this soil, anoxic conditions and reduced tillage (little plowing seem to favor a higher degree of humification of the soil organic matter compared with aerated conditions and conventional tillage.No ciclo do carbono terrestre, o solo contém maiores estoques de carbono que a vegetação e a atmosfera. Manter e conservar as concentrações de carbono orgânico no solo usando práticas de manejo pode aumentar sua fertilidade e produtividade. Por meio da espectroscopia de fluorescência pelo método da matriz excitação/emissão, avaliou-se o impacto de técnicas de manejo agrícolas e a influência do regime (inundado e drenado sobre a estrutura das substâncias húmicas do referido solo. Seis amostras de um

  19. Replenishing Humic Acids in Agricultural Soils

    Directory of Open Access Journals (Sweden)

    Michael Susic

    2016-09-01

    Full Text Available For many decades, it was commonly believed that humic acids were formed in soils by the microbial conversion of plant lignins. However, an experiment to test whether these humic acids were formed prior to plant matter reaching the soil was never reported until the late 1980s (and then only as a side issue, even though humic acids were first isolated and reported in 1786. This was a serious omission, and led to a poor understanding of how the humic acid content of soils could be maintained or increased for optimum fertility. In this study, commercial sugar cane mulch and kelp extracts were extracted with alkali and analyzed for humic acid content. Humic acids in the extracts were positively identified by fluorescence spectrophotometry, and this demonstrated that humic acids are formed in senescent plant and algal matter before they reach the soil, where they are then strongly bound to the soil and are also resistant to microbial metabolism. Humic acids are removed from soils by wind and water erosion, and by water leaching, which means that they must be regularly replenished. This study shows that soils can be replenished or fortified with humic acids simply by recycling plant and algal matter, or by adding outside sources of decomposed plant or algal matter such as composts, mulch, peat, and lignite coals.

  20. Preparing for retirement - new seminars

    CERN Multimedia

    Human Resources Department

    2015-01-01

    We would like to take the opportunity to inform you about a new programme related to retirement, organised by the Human Resources Department. Retirement marks the end of a career and the start of a new chapter in life.  In all cases, being well-informed and prepared is necessary to cope successfully with this transition. The programme has been developed for staff members and consists of two seminars: Leaving CERN (half day seminar): short presentations by internal speakers, focusing on what options CERN offers at the end of your career: organised once per year, next session scheduled on 24 November 2015, in the afternoon, enrolment and more information on Indico.   Preparation for retirement (2-day seminar): interactive workshop (in small groups) delivered by external experts, focusing on how to prepare psychologically as well as practically to cope with all the changes retirement brings: organised regularly in 2016, in English or ...

  1. Composição lignocelulósica e isótopica da vegetação e da matéria orgânica do solo de uma turfeira tropical: II - substâncias húmicas e processos de humificação Lignocellulosic and isotopic composition of vegetation and soil organic matter of a tropical peat: II humic substances and humification processes

    Directory of Open Access Journals (Sweden)

    Alexandre Christofaro Silva

    2013-02-01

    sob a FES, em relação ao CLU. O δ13C da lignina apresenta similaridade elevada em relação ao δ13C da humina, dos ácidos húmicos e dos ácidos fúlvicos. As variações na composição lignocelulósica das espécies que colonizam o CLU e a FES promovem diferenças nas taxas e nos produtos da humificação da MOS.Much of the organic matter of a typical peat consists of humic substances, mainly formed via humification of organic residues, decomposed by soil microorganisms, and by the polymerization of organic compounds to functional macromolecules, which are normally more resistant to degradation. The fundamental pathways governing the humification of soil organic matter (SOM are not well understood so far, and most available data about the identified chemical precursors of humic substances and the main chemical routes by which they are transformed in the peat environment are still poorly understood. What is clear is that all routes involve lignin as a chemical intermediate. Stable isotopes (δ13C, δ15N can be used to trace humification processes of the soil organic matter (SOM, by identifying their precursors. The purpose of this study was to compare the isotopic composition of vegetation materials from the two bog vegetation types that colonize a tropical highland peatland: moist grassland (CLU and semideciduous forest (FES, based on the isotopic composition of humic substances of SOM. The whole area of the studied peatland occupies 81.75 ha. To identify the isotopic and lignocellulosic vegetation composition, materials of the dominant species of each vegetation type were sampled. Soil samples were collected from three representative sites per vegetation type, at intervals of 5 cm from the surface down to a depth of 50 cm. The humic substances were isolated from these samples; signals of δ13C and δ15N were determined for the humic fractions. The lignin and and δ13C values were higher in vegetation and SOM under FES than in SOM under CLU. Humin contents were

  2. Israel Seminar 2002-2003

    CERN Document Server

    Milman, Vitali D

    2004-01-01

    The Israeli GAFA seminar (on Geometric Aspect of Functional Analysis) during the years 2002-2003 follows the long tradition of the previous volumes. It reflects the general trends of the theory. Most of the papers deal with different aspects of the Asymptotic Geometric Analysis. In addition the volume contains papers on related aspects of Probability, classical Convexity and also Partial Differential Equations and Banach Algebras. There are also two expository papers on topics which proved to be very much related to the main topic of the seminar. One is Statistical Learning Theory and the other is Models of Statistical Physics. All the papers of this collection are original research papers.

  3. Impacto da conversão floresta - pastagem nos estoques e na dinâmica do carbono e substâncias húmicas do solo no bioma Amazônico Impact of forest-pasture conversion on stocks and dynamics of soil carbon and humic substances in the Amazon

    Directory of Open Access Journals (Sweden)

    Edson Alves de Araújo

    2011-03-01

    of Rio Branco and comprises an area of bamboo- and palm-dominated open forest with two B. brizantha pastures of 3 and 10 years old. The second site, dominated by a dystrophic Red Yellow Latosol (Oxisol, is located in the municipality of Senador Guiomard and comprises an area of dense forest and a 20-year old B. brizantha pasture. In each site soil samples were collected in triplicate at depths of 0-5, 5-10, 10-20 and 20-40 cm. Samples were evaluated for physical and chemical characteristics, C of humic substances and light organic matter, and the isotopic composition of soil and its organic fractions to 1 m depth, determining the percentage of C derived of both grassland and forest. There were increases in stocks of soil C and δ13C soil with the time of grazing in both sites. The percentage of C derived from pasture was much higher in the surface layer of the Senador Guiomard site following 20 years of grazing, with proportions that reached 70% of the total C. δ13C values for the humic acids ranged from -12.19 to -17.57 ‰, indicating a higher proportion of C derived from pasture. The MOS structural stability inferred by the relationship of the humin with both fulvic acid and humic acid fractions (HUM / FAF + FAH tended to decrease in grassland ecosystems when compared with native forests.

  4. Promoção de enraizamento de microtoletes de cana-de-açúcar pelo uso conjunto de substâncias húmicas e bactérias diazotróficas endofíticas Rooting of micro seed pieces by combined use of humic substances and endophytic diazotrophic bacteria in sugar cane

    Directory of Open Access Journals (Sweden)

    Roberto Batista Marques Júnior

    2008-06-01

    éficos da inoculação de estirpes selecionadas de H. seropedicae, já para ácidos húmicos, as respostas positivas independem da termoterapia. A promoção do crescimento radicular por AH e a fixação biológica de N2 podem representar uma estratégia inovadora para produção sustentada em sistemas agrícolas.Besides the direct nutritional effect of mineralization of organic matter or by biological nitrogen fixation activity, the humic substances and endophytic diazotrophic bacteria can directly influence plant metabolism, modifying plant growth and development patterns. The purpose of this study was to evaluate the effect of the combined use of humic acid (HA and Herbaspirillum seropedicae, an endophytic nitrogen-fixing bacteria, on the root growth of seed pieces - heat-treated or not - of the sugarcane variety RB 72 454. After hot water treatment, the cane cuttings were immersed for 12 hours as follows: in water (control plant, in HA solution (20 mg L-1 of C from vermicompost, in bacterial inoculant of H. seropedicae, strain HRC54 (10(8 cells mL-1, and in a combination of bacteria and HA. Root growth was improved by 60 to 118 % in length and from 33 % to 233 % in surface area on sugarcane plant treatments compared to control, with more pronounced effect in plants under heat treatment. Likewise, the positive effect of the combinded treatment (bacteria inoculation and humic acid on shoot and root biomass was significant compared to the control with heat-treated cuts. For non-heated seed pieces, bacteria inoculation did not result in a positive plant growth effect, but only in the presence of humic acid. The combined or isolated use of both HA and bacteria did not significantly modify the bacteria population in the root tissue of heat-untreated sugarcane. For heat-treated cuts, bacteria inoculation, combined or not with HA, increased the size of diazotrophic bacteria population on roots. The results highlight the importance of thermotherapy to increase the positive

  5. Variability of humic acid properties depending on their precursor material: a study of peat profiles

    Science.gov (United States)

    Klavins, Maris; Purmalis, Oskars

    2015-04-01

    Analysis of variation of peat composition, presence of trace elements in the peat and HSs within peat profiles can give information on the character of transformation of organic matter, important for C biogeochemical cycling, but also about impacts of climate change and human activities. In peat the transformation and decay process of living organic matter (humification) is retarded by the acidic and anaerobic environment, but at the same time the peat can provide information on environmental and paleo-environmental conditions of the past. The aim of the present study is to analyze the elemental and functional composition, spectral characteristics of humic acids isolated from a well characterized raised bog peat profiles to evaluate the impact of the character of humification processes on the peat HA properties. A comparative and complex characterization of humic acids (HAs) isolated from peat profiles of different origin in Latvia was carried out. Elemental and functional analysis of the isolated HAs was done, their acidity and molecular weights estimated. Spectral characterization included UV-Vis, IR, and electron spin resonance and fluorescence spectra. Structural characterization of HAs was by both 1H and 13C nuclear magnetic resonance spectra. Comparison of position of studied humic acids in the Van Krevelen graph was done, thus locating them in the biogeochemical transformation processes of organic matter. Properties of HAs isolated from the Latvian peat were compared with HA from other sources (soil, water, coal and synthetic humic substances). Major properties of peat HAs depended on their origin, indicating the importance of humification processes. HAs isolated from peat of more recent origin were more similar to soil HAs, but from older sources there was a greater degree of humification. Changes of surface tension of solutions of humic acids stress the differences in aggregation character - ability to form supramacromolecular complexes of humic substances

  6. Isotherm, kinetic and thermodynamics study of humic acid removal process from aquatic environment by chitosan nano particle

    Directory of Open Access Journals (Sweden)

    Maryam Ghafoori

    2016-09-01

    Full Text Available Background and Aim: Humic substances include natural organic polyelectrolyte materials that formed most of the dissolved organic carbon in aquatic environments. Reaction between humic substances and chlorine leading to formation of disinfection byproducts (DBPs those are toxic, carcinogenic and mutagenic. The aim of this study was investigation of isotherms, kinetics and thermodynamics of humic acid removal process by nano chitosan from aquatic environment. Materials and Methods: This practical research was an experimental study that performed in a batch system. The effect of various parameters such as pH, humic acid concentration, contact time, adsorbent dosage, isotherms, thermodynamics and Kinetics of humic acid adsorption process were investigated. Humic acid concentration measured using spectrophotometer at wave length of 254 nm. Results: The results of this research showed that maximum adsorption capacity of nanochitosan that fall out in concentration of 50 mg/l and contact time of 90 minutes was 52.34 mg/g. Also, the maximum adsorption was observed in pH = 4 and adsorbent dosage 0.02 g. Laboratory data show that adsorption of humic acid by nanochitosan follow the Langmuir isotherm model. According to result of thermodynamic study, entropy changes (ΔS was equal to 2.24 J/mol°k, enthalpy changes (ΔH was equal to 870 kJ/mol and Gibbs free energy (ΔG was negative that represent the adsorption process is spontaneous and endothermic. The kinetics of adsorption has a good compliant with pseudo second order model. Conclusion: Regarding to results of this study, nano chitosan can be suggested as a good adsorbent for the removal of humic acids from aqueous solutions.

  7. SOIL POLLUTION OF SELECTED PAHS AS A FACTOR AFFECTING THE PROPERTIES OF HUMIC ACIDS

    Directory of Open Access Journals (Sweden)

    Bożena Dębska

    2014-01-01

    Full Text Available It is well-known that the properties of humus soil substances (including humic acids are soil-type-specific. However, one shall consider the fact that properties of organic matter of soil can be modified by farming system (crop rotation, fertilisation as well as other external factors, including pollutants; PAHs. The objective of the paper is to determine the effect of a single-time pollution of soils with high rates of PAHs on the properties of humic acids. The research was performed with the samples of soils representative for the Kujawy and Pomorze Region (Phaeozems, Luvisol, Haplic Arenosols, Fluvisols. Soil samples were polluted with selected PAHs; fluorene, anthracene, pyrene and chrysene at the amount corresponding to 100 mg PAHs · kg-1. Treatments, i.e., soils + PAHs, were incubated for 180 and 360 days at the temperature of 20–25 ºC and at constant moisture of 50 % of field water capacity. Humic acids were extracted from the soil samples prior to and after 180 and 360 days of incubation. The following analyses were performed for separating humic acids: elemental composition, UV-VIS and IR spectrophotometric analyses, susceptibility to oxidation. Results demonstrated that a single introduction of fluorene, anthracene, pyrene and chrysene at very high rates into soils affects the properties of humic acids. There was mostly recorded a decrease in coefficients of absorbance A2/6 and A4/6, an increase in the parameter defining the susceptibility of humic acids to oxidation. There were also noted changes in the pattern of spectra in infrared and the values of the parameter defining the degree of internal oxidation of the humic acids molecules.

  8. Chemical immobilisation of humic acid on silica

    NARCIS (Netherlands)

    Koopal, L.K.; Yang, Y.; Minnaard, A.J.; Theunissen, P.L.M.; Riemsdijk, W.H. van

    1998-01-01

    Immobilisation of purified Aldrich humic acid (PAHA) on aminopropyl silica and glutaraldehyde-activated aminopropyl silica has been investigated. In general the humic acid is bound to the solid by both physical and chemical bonds. The physically adsorbed HA can be released to a large extent at high

  9. Seminar on Usher's Syndrome: Proceedings.

    Science.gov (United States)

    Rochester School for the Deaf, NY.

    Summarized are the presentation of M. Vernon and the Comments of primary panelists from a seminar on Usher's Syndrome, a genetic disease involving congenital deafness and progressive loss of vision due to retinitis pigmentosa. The following topics are addressed: genetics today, nature of Usher's Syndrome, symptoms, prevalence, lay diagnosis for…

  10. Music, Art, Drama, Civilization Seminar.

    Science.gov (United States)

    Hampton City School Board, VA.

    This 1-year elective seminar for high school students is to be taught in five units--Introduction, the Ancient World, the Medieval World, the Renaissance, and the Modern World--with emphasis on four basic themes expressed creatively throughout western history: (1) the common man, (2) the individual, (3) religion, and (4) conflict. Instruction on a…

  11. Israel Seminar 1989-90

    CERN Document Server

    Milman, Vitali

    1991-01-01

    The scope of the Israel seminar in geometric aspects of functional analysis during the academic year 89/90 was particularly wide covering topics as diverse as: Dynamical systems, Quantum chaos, Convex sets in Rn, Harmonic analysis and Banach space theory. The large majority of the papers are original research papers.

  12. Seminar with Jean Claude Galey

    OpenAIRE

    Galey, Jean Claude

    2004-01-01

    A talk for one hour, and then questions and discussion for one hour, chaired by Alan Macfarlane. Seminar and questions with Jean Claude Galey, the director of the Center of South Asiian Studies, Paris, on the organization of French academic research, in particular in the social sciences.

  13. International Seminar in Mathematics Education

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 7; Issue 12. International Seminar in Mathematics Education. Shailesh A Shirali. Information and Announcements Volume 7 Issue 12 December 2002 pp 95-96. Fulltext. Click here to view fulltext PDF. Permanent link:

  14. Seminar on Nano-biotechnology

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 12. Seminar on Nano-biotechnology. Information and Announcements Volume 13 Issue 12 December 2008 pp 1191-1191. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/013/12/1191-1191 ...

  15. Humic acid from Shilajit – a physico-chemical and spectroscopic characterization

    Directory of Open Access Journals (Sweden)

    SURAJ P. AGARWAL

    2010-03-01

    Full Text Available Shilajit is a blackish–brown exudation, consisting of organic substances, metal ions and minerals, from different formations, commonly found in the Himalayan region (1000–3000 m from Nepal to Kashmir. Shilajit can also be collected throughout the mountain regions in Afghanistan, Bhutan, China, Bajkal, throughout Ural, Caucasus and Altai mountains also, at altitudes between 1000 to 5000 m. The major physiological action of shilajit has been attributed to the presence of bioactive dibenzo-α-pyrones together with humic and fulvic acids, which act as carrier molecules for the active ingredients. In this work, the aim was to extract humic acid from Shilajit from various sources and characterised these humic acids based on their physicochemical properties, elemental analysis, UV/Vis and FTIR spectra, X-ray diffraction pattern and DSC thermograms. The spectral features obtained from UV/Vis, FTIR, XRD and DSC studies for samples of different origins showed a distinct similarity amongst themselves and in comparison to soil humic acids. The surfactant properties of the extracted fulvic acids were investigated by determining the effect of increasing concentration on the surface tension of water. The study demonstrated that humic acids extracted from shilajit indeed possessed surfactant properties.

  16. ORGANIC MATTER AND HUMIC FRACTIONS OF A HAPLIC ACRISOL AS AFFECTED BY COMPOSTED PIG SLURRY

    Directory of Open Access Journals (Sweden)

    Ana Cristina Lüdtke

    2016-01-01

    Full Text Available The goal of this study was to investigate the effect of composted pig slurry (PS on the organic matter concentration and distribution of humic acid (HA, fulvic acid (FA and humin (HU fractions. The fractions were quantified following the addition of composted PS to the soil, which was produced with no acidification (T2 or with acidification with H3PO4 (T3; and in soil without compost addition (T1. The HA chemical composition was analyzed by FTIR spectroscopy. The addition of the two composts did not change the soil carbon concentration but affected the distribution of the humic fractions. For the three treatments, the carbon concentration of humic substances increased until 52 days following compost addition, with more pronounced increases with the addition of non-acidified PS compost (14.5 g kg-1 and acidified PS compost (15.1 g kg-1. This increase was reflected in both the FA and HA concentrations. The addition of compost with PS acidification resulted in the formation of larger humic micelles (HA with higher aromatic content and fewer functional groups than the non-acidified PS compost. These findings, together with a lower proportion of carbohydrate-type structures, indicated the presence of more stable humic micelles in the soil treated with acidified PS compost.

  17. Spectroscopic studies of humic acids from subsurface sediment samples collected across the Aegean Sea

    Directory of Open Access Journals (Sweden)

    F. SAKELLARIADOU

    2006-12-01

    Full Text Available 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.

  18. Iodine binding to humic acid

    OpenAIRE

    Bowley, Hannah E.; Young, Scott D.; Ander, E. Louise; Crout, Neil J.M.; Crout, N.M.J.; Watts, Michael J.; Bailey, Elizabeth H.

    2016-01-01

    The rate of reactions between humic acid (HA) and iodide (I-) and iodate (IO3-) have been investigated in suspensions spiked with 129I at concentrations of 22, 44 and 88 µg L-1 and stored at 10oC. Changes in the speciation of 129I-, 129IO3- and mixed (129I-+129IO3-) spikes were monitored over 77 days using liquid chromatography inductively coupled plasma mass spectrometry (LC-ICP-MS). In suspensions spiked with 129I- 25% of the added I- was transformed into organic iodine (Org-129I) within...

  19. Technical Training seminar: Texas Instruments

    CERN Multimedia

    2006-01-01

    Monday 6 November TECHNICAL TRAINING SEMINAR 14:00 to 17:30 - Training Centre Auditorium (bldg. 593) Texas Instruments Technical Seminar Michael Scholtholt, Field Application Engineer / TEXAS INSTRUMENTS (US, D, CH) POWER - A short approach to Texas Instruments power products Voltage mode vs. current mode control Differentiating DC/DC converters by analyzing control and compensation schemes: line / load regulation, transient response, BOM, board space, ease-of-use Introduction to the SWIFT software FPGA + CPLD power solutions WIRELESS / CHIPCON Decision criteria when choosing a RF platform Introduction to Texas Instruments wireless products: standardized platforms proprietary platforms ( 2.4 GHz / sub 1 GHz) development tools Antenna design: example for 2.4 GHz questions, discussion Industrial partners: Robert Medioni, François Caloz / Spoerle Electronic, CH-1440 Montagny (VD), Switzerland Phone: +41 24 447 0137, email: RMedioni@spoerle.com, http://www.spoerle.com Language: English. Free s...

  20. Technical Training: Technical Training Seminar

    CERN Multimedia

    2004-01-01

    TECHNICAL TRAINING Monique Duval tel. 74924 technical.training@cern.ch Monday 9 February 2004 From 10:00 to 12:00 - IT Auditorium - bldg. 31, 3rd floor ANSOFT High-Frequency Seminar David Prestaux, Application Engineer, ANSOFT F-78535 BUC, France This Technical Training seminar will present two Ansoft application products: Ansoft HFSS and Ansoft Designer. Ansoft HFSS makes use of the Finite Element Method (FEM) to calculate field solutions from first principles. It can accurately predict all high-frequency behaviours such as dispersion, mode conversion, and losses due to materials and radiation. Ansoft Designer is a suite of design tools to fully integrate high-frequency, physics-based electromagnetic simulations into a seamless system-level simulation environment. Ansoft Designer uses a simple interface to give complete control over every design task, by a method allowing multiple solvers, Solver on Demand. • Introduction • Overview of the Ansoft Total solution • Ansoft HFSS 9...

  1. Technical Training: Technical Training Seminar

    CERN Multimedia

    2004-01-01

    Tuesday 30 March TECHNICAL TRAINING SEMINAR From 9:00 to 12:00 and from 13:00 to 16:00 hrs - Council Chamber, Salle B, Salle des Pas Perdus National Instruments (NI) on Tour 2004 Claudia Jüngel, Evrem Yarkin, Joel Clerc, Hervé Baour / NATIONAL INSTRUMENTS The special event NI on Tour 2004, run in Germany, Austria and Switzerland, will be at CERN on March 30. Technical seminars and free introductory courses will be offered all day long in the Council Chamber, Salle B, and Salle des Pas Perdus (buildings 61 and 503). Technical conferences: 09:00 - 12:00 Data acquisition systems on PCs. Industrial measurement and control techniques. 13:00 - 16:00 Advanced LabVIEW software and PXI instrumentation. Measuring instruments and system components for teststand automation. Introductory courses: 09:00 - 12:00 DIAdem: Data analysis and presentation 13:00 - 16:00 Data acquisition with LabVIEW Language: English and French Free special seminar. Registration is recommended with National Instruments Switzerland (please sp...

  2. Technical Training: Technical Training Seminar

    CERN Multimedia

    2004-01-01

    Tuesday 30 March TECHNICAL TRAINING SEMINAR From 9:00 to 12:00 and from 13:00 to 16:00 hrs - Council Chamber, Salle B, Salle des Pas Perdus National Instruments (NI) on Tour 2004 Claudia Jüngel, Evrem Yarkin, Joel Clerc, Hervé Baour / NATIONAL INSTRUMENTS The special event NI on Tour 2004, run in Germany, Austria and Switzerland, will be at CERN on March 30. Technical seminars and free introductory courses will be offered all day long in the Council Chamber, Salle B, and Salle des Pas Perdus (buildings 61 and 503). Technical conferences: 09:00 - 12:00 Data acquisition systems on PCs. Industrial measurement and control techniques. 13:00 - 16:00 Advanced LabVIEW software and PXI instrumentation. Measuring instruments and system components for teststand automation. Introductory courses: 09:00 - 12:00 DIAdem: Data analysis and presentation 13:00 - 16:00 Data acquisition with LabVIEW Language: English and French Free special seminar. Registration is recommended with National Instruments Swi...

  3. Humic Acid-Like and Fulvic Acid-Like Inhibition on the Hydrolysis of Cellulose and Tributyrin

    NARCIS (Netherlands)

    Fernandes, Tania V.; van Lier, Jules B.; Zeeman, Grietje

    2015-01-01

    Enzymatic hydrolysis of complex wastes is a critical step for efficient biogas production in anaerobic digesters. Inhibition of this hydrolytic step was studied by addition of humic acid-like (HAL) and fulvic acid-like (FAL) substances, extracted from maize silage and fresh cow manure, to batch

  4. Humic Acid-Like and Fulvic Acid-Like Inhibition on the Hydrolysis of Cellulose and Tributyrin

    NARCIS (Netherlands)

    Fernandes, T.V.; Lier, van J.B.; Zeeman, Grietje

    2015-01-01

    Enzymatic hydrolysis of complex wastes is a critical step for efficient biogas production in anaerobic digesters. Inhibition of this hydrolytic step was studied by addition of humic acid-like (HAL) and fulvic acid-like (FAL) substances, extracted from maize silage and fresh cow manure, to batch

  5. Extracellular polymeric substances act as transient media in extracellular electron transfer of Shewanella oneidensis MR-1

    DEFF Research Database (Denmark)

    Xiao, Yong; Zhang, Jingdong; Ulstrup, Jens

    It is well known that microorganism is surrounded by extracellular polymeric substances (EPS) which include polysaccharides, proteins, glycoproteins, nucleic acids, phospholipids, and humic acids. However, previous studies on microbial extracellular electron transfer (EET) are conducted on cells...

  6. Potential origin and formation for molecular components of humic acids in soils

    Science.gov (United States)

    Hatcher, Patrick; DiDonato, Nicole; Waggoner, Derek

    2016-04-01

    Humification is defined as the process by which plant and microbial debris are transformed in to humic substances. Proposed pathways for the formation of humic substances, include the lignin and lignin decomposition theories, the lignin-polyphenol theory as well as the melanoidin pathway. It is generally accepted that a combination of several of these pathways with some modifications may be responsible for producing humic substances. The current study examines humic acids from numerous soil samples to demonstrate their molecular composition. In addition we provide an explanation for the formation of these molecules that introduces a new perspective of the humification process. Our work utilizes advanced analytical techniques such as ESI-FTICR-MS and solid state NMR to more completely characterize humic acids at the molecular level. Methods Humic acids were extracted from soils using 0.5 M NaOH followed by treatment with a Dowex™ ion-exchange resin to remove sodium ions. Solid State 13C NMR spectra were obtained on a Bruker 400 MHz Avance II spectrometer equipped with a 4 mm solid state MAS probe. ESI-FTICR-MS analysis was conducted in the negative ion mode on a Bruker Daltonics 12 Tesla Apex Qe FTICR-MS instrument equipped with an Apollo II ESI source. Results: Soil humic acids from numerous soils were investigated in this study. The molecular formulas calculated from ultrahigh resolution mass spectra of well humified soils fall clearly into two predominant regions consisting of condensed aromatic molecules as well as high H/C, low O/C carboxyl-containing aliphatic molecules (CCAM). In contrast, the spectral data for humic acids from a poorly humified spodosol soil show a less dramatic separation of these regions, with relatively more molecular formula plotting in the lignin-like region and relatively fewer condensed aromatic molecules. From the mass spectral observations made for the humic acids, we can readily discern a relationship based on degree of

  7. BORON CONCENTRATION IN HUMIC AND FULVIC ACID EXTRACTS OF SOIL EPIPEDON IN SAN VITALE PINEWOOD (RAVENNA, ITALY

    Directory of Open Access Journals (Sweden)

    Maddalena Pennisi

    2010-08-01

    Full Text Available Humified Soil Organic Matter (SOM plays a crucial role in the assessment of soil quality since it makes up a significant part of the total organic carbon and nitrogen in soils. High concentrations of humic and fulvic acids may be presents in soils and subordinately in sediments. These substances can potentially act as a significant reservoir of adsorbed boron as well as a source of this element to soil solution, rivers, and lakes. The aim of this study was to investigate boron in humic substances (e.g. humic and fulvic acids of soil epipedon. The San Vitale pinewood was selected as the study site and three samples - classified as Sodic Psammaquents and Typic Psammaquants - of the A1-horizon epipedon were analyzed for humic and fulvic acids and boron contents. The knowledge of the mechanisms of boron interaction with SOM is important for a better understanding of the water/rock interaction in the superficial soil environment, and to envisage the application of the blending of boron into humic acid granules in agricultural practices.

  8. Buffer capacity of humic acid: thermodynamic approach.

    Science.gov (United States)

    Pertusatti, Jonas; Prado, Alexandre G S

    2007-10-15

    Commercial humic acid was dialyzed and characterized by infrared, UV/vis spectroscopy, (13)C NMR spectrometry, thermogravimetry, and elemental analysis. The dialyzed humic acid was titrated with HNO(3) and NaOH in order to obtain the buffer capacity value (beta). The humic acid presented buffer behavior by base and acid addition, and moreover, an excellent buffer capacity by addition of NaOH. Humic acid showed buffer action between pH 5.5 and 8.0, and a maximum buffer capacity at pH 6.0. The same study was followed calorimetrically to determinate the enthalpy of interaction between H(+)/OH(-) and buffer, which resulted in a maximum enthalpy of -38.49 kJ mol(-1) at pH 6.0. This value suggests that the buffer activity is based on chemisorption of proton and hydroxyl.

  9. Imidacloprid adsorption by soils treated with humic substances ...

    African Journals Online (AJOL)

    USER

    2010-03-29

    Mar 29, 2010 ... (HAs) were added to soil to enhance the amount of soil organic carbon (SOC) by 2.5, 5.0 and 10.0 g kg-1. Imidacloprid sorption of the treated ... are the dominant organic components in soils (Stevenson,. 1994) and generally comprise more than ..... Fungicides and insecticides applied to pelleted sugar-beet ...

  10. Characterization of humic-like substances in Arctic aerosols

    DEFF Research Database (Denmark)

    Nguyen, Quynh T.; Kristensen, Thomas Bjerring; Hansen, Anne Maria K.

    2014-01-01

    -Arctic atmosphere, focusing on the chemical characterization and mass contribution of HULIS to the total suspended particle (TSP) mass using weekly aerosol samples collected at Station Nord, northeast Greenland every fourth week during 2010. Average HULIS-C concentration was 11ng C m(-3) during the darker months...... (November-April) and 4ng C m(-3) during the other months (May-October) with an annual mass concentration of 0.020.01 mu gm(-3). HULIS-C contributed to 3-16% of water-soluble organic carbon (WSOC), whereas HULIS accounted for 0.7-4.1% of TSP mass, with TSP typically below 1.0 mu gm(-3). Concentrations of OC...

  11. Usage of humic materials for formulation of stable microbial inoculants

    Science.gov (United States)

    Kydralieva, K. A.; Khudaibergenova, B. M.; Elchin, A. A.; Gorbunova, N. V.; Muratov, V. S.; Jorobekova, Sh. J.

    2009-04-01

    of the product. It is known that humic substances can increase of live organism resistance to stress loads, in particular to chemical stress, low and high temperature. Spray- and fluidized-bed drying and addition of humate-based drying protectants were evaluated for the development of dry formulations of biocontrol and plant growth promoting rhizobacteria. The drying protectants - humic acids and sodium humate gave the highest initial survival rates and the most stable formulations, without significant losses of viability after storage for 1 month at 30oC. As a result, the specific plant growth promoting effect is retained. Thus, humic materials have an unfulfilled potential for biotechnology industries based on such applications. Acknowledgement. This research was supported by the grant of ISTC KR-993.2.

  12. 33. MPA seminar 2007. Proceedings; 33. MPA Seminar 2007. Vortraege

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    In a single PDF file, the CD-ROM contains all papers presented at the 33. MPA Seminar in Stuttgart. Subjects: Life management of nuclear facilities: Materials, integrity analysis, fracture mechanics; Behaviour of welds; Material development and qualification for power plants with enhanced steam parameters; monitoring concepts (e.g. state monitoring of components, test concepts); Design of pipelines with flanged joints; Assembly and joining technology for flanged joints; Non-destructive testing in plant engineering; Materials for new nuclear reactors. Many of the papers are available as separate items in this database. [German] In einer einzigen PDF-Datei sind auf der CD-ROM alle Vortraege enthalten, die auf dem 33. MPA-Seminar in Stuttgart gehalten wurden. Die Themenschwerpunkte sind: Lebensdauermanagement kerntechnischer Anlagen - Werkstoffverhalten, Integritaetsanalyse, Bruchmechanik; Verhalten von Schweissverbindungen; Werkstoffentwicklung und -qualifizierung fuer Kraftwerke mit erhoehten Dampfparametern; Ueberwachungskonzepte (z.B. Zustandsueberwachung von Komponenten, Pruefkonzepte); Auslegung von Rohrleitungen mit Flanschverbindungen; Montage- und Dichtungstechnik fuer Flanschverbindungen; Zerstoerungsfreie Pruefung in der Anlagentechnik; Werkstoffe fuer neue Kernreaktoren. Ein grosser Teil der Vortraege wurde separat aufgenommen.

  13. Thermodynamic Characterization of Humic Acid-surfactant Interaction: New Insights into the Characteristics and Structure of Humic Acids

    Directory of Open Access Journals (Sweden)

    Leonardus Vergütz

    2015-12-01

    Full Text Available ABSTRACT Humic acids (HA are a component of humic substances (HS, which are found in nearly all soils, sediments, and waters. They play a key role in many, if not most, chemical and physical properties in their environment. Despite the importance of HA, their high complexity makes them a poorly understood system. Therefore, understanding the physicochemical properties and interactions of HA is crucial for determining their fundamental role and obtaining structural details. Cationic surfactants are known to interact electrostatically and hydrophobically with HA. Because they are a very well-known and characterized system, they offer a good choice as molecular probes for studying HA. The objective of this study was to evaluate the interaction between cationic surfactants and HA through isothermal titration calorimetry in a thermodynamic manner, aiming to obtain information about the basic structure of HA, the nature of this interaction, and if HA from different origins show different basic structures. Contrary to what the supramolecular model asserts, HA structure is not loosely held, though it may separate depending on the conditions the HA are subjected to in their milieu. It did not show any division or conformational change when interacting with surfactants. The basic structure of the HA remains virtually the same regardless of the different sources and compositions of these HA.

  14. Israel Seminar 2001-2002

    CERN Document Server

    Schechtman, Gideon

    2003-01-01

    The proceedings of the Israeli GAFA seminar on Geometric Aspect of Functional Analysis during the years 2001-2002 follow the long tradition of the previous volumes. They continue to reflect the general trends of the Theory. Several papers deal with the slicing problem and its relatives. Some deal with the concentration phenomenon and related topics. In many of the papers there is a deep interplay between Probability and Convexity. The volume contains also a profound study on approximating convex sets by randomly chosen polytopes and its relation to floating bodies, an important subject in Classical Convexity Theory. All the papers of this collection are original research papers.

  15. Israel Seminar 1996–2000

    CERN Document Server

    Schechtman, Gideon

    2000-01-01

    This volume of original research papers from the Israeli GAFA seminar during the years 1996-2000 not only reports on more traditional directions of Geometric Functional Analysis, but also reflects on some of the recent new trends in Banach Space Theory and related topics. These include the tighter connection with convexity and the resulting added emphasis on convex bodies that are not necessarily centrally symmetric, and the treatment of bodies which have only very weak convex-like structure. Another topic represented here is the use of new probabilistic tools; in particular transportation of measure methods and new inequalities emerging from Poincaré-like inequalities.

  16. International Seminar on Gasification 2008

    Energy Technology Data Exchange (ETDEWEB)

    Held, Joergen (ed.)

    2008-11-15

    In total 20 international and national experts were invited to give presentations (The PPT-presentations are collected in this volume).The seminar was divided into three parts: Production technologies; Applications - Gas turbines and gas Engines - Biomethane as vehicle fuel- Syngas in industrial processes; Strategy, policy and vision. Production of synthetic fuels through gasification of biomass is expected to develop rapidly due to political ambitions related to the strong fossil fuel dependency, especially within the transportation sector, security of supply issues and the growing environmental concern. Techniques that offer a possibility to produce high quality fuels in an efficient and sustainable way are of great importance. In this context gasification is expected to play a central part. The indirect gasification concept has been further developed in recent years and there are now pilot and demonstration plants as well as commercial plants in operation. The RandD activities at the semi-industrial plant in Guessing, Austria have resulted in the first commercial plant, in Oberwart. The design data is 8.5 MW{sub th} and 2.7 MW{sub e} which gives an electric efficiency of 32 % and the possibility to produce biomethane. In this scale conventional CHP production based on combustion of solid biomass and the steam cycle would result in a poor electric efficiency. Metso Power has complemented the 12 MW{sub th} CFB-boiler at Chalmers University of Technology, Gothenburg, Sweden with a 2 MW{sub th} indirect gasifier. The gasifier is financed by Gothenburg Energy and built for RD purposes. Gothenburg Energy in collaboration with E.ON Sweden will in a first stage build a 20 MW plant for biomethane production (as vehicle fuel and for grid injection) in Gothenburg based on the indirect gasification technology. The plant is expected to be in operation in 2012. The next stage involves an 80 MW plant with a planned start of operation in 2015. Indirect gasification of biomass

  17. Factors Influencing Seminar Learning and Academic Achievement

    NARCIS (Netherlands)

    Spruijt, Annemarie; Leppink, Jimmie; Wolfhagen, Ineke; Bok, Harold; Mainhard, Tim; Scherpbier, Albert; van Beukelen, Peter; Jaarsma, Debbie

    2015-01-01

    Many veterinary curricula use seminars, interactive educational group formats in which some 25 students discuss questions and issues relating to course themes. To get indications on how to optimize the seminar learning process for students, we aimed to investigate relationships between factors that

  18. Factors influencing seminar learning and academic achievement

    NARCIS (Netherlands)

    Spruijt, Annemarie; Leppink, Jimmie; Wolfhagen, Ineke; Bok, Harold; Mainhard, Tim; Scherpbier, Albert; Van Beukelen, Peter; Jaarsma, Debbie

    2015-01-01

    Many veterinary curricula use seminars, interactive educational group formats in which some 25 students discuss questions and issues relating to course themes. To get indications on how to optimize the seminar learning process for students, we aimed to investigate relationships between factors that

  19. Public-Key Cryptography (Dagstuhl Seminar 16371)

    OpenAIRE

    Fischlin, Marc; May, Alexander; Pointcheval, David; Rabin, Tal

    2017-01-01

    This report documents the program and results of Dagstuhl seminar 16731 “Public-Key Cryptography” which took place September 11th -16th, 2016. The goal of the seminar was to bring together different sub areas from public-key cryptography and to promote research among these areas.

  20. Proceedings of the third NUCEF seminar

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-06-01

    The Third NUCEF Seminar was held at JAERI Tokai Establishment on 24 February 1998. This seminar was planned by researchers in JAERI for effective research promotion and cooperation, and researchers from both the inside and outside of JAERI presented one plenary session and 12 papers in the following three technical sessions: Criticality Safety, Reprocessing and Partitioning, and Radioactive Waste Management. (J.P.N.)

  1. Sorption mechanisms of phenanthrene, lindane, and atrazine with various humic acid fractions from a single soil sample.

    Science.gov (United States)

    Wang, Xilong; Guo, Xiaoying; Yang, Yu; Tao, Shu; Xing, Baoshan

    2011-03-15

    The sorption behavior of organic compounds (phenanthrene, lindane, and atrazine) to sequentially extracted humic acids and humin from a peat soil was examined. The elemental composition, XPS and (13)C NMR data of sorbents combined with sorption isotherm data of the tested compounds show that nonspecific interactions govern sorption of phenanthrene and lindane by humic substances. Their sorption is dependent on surface and bulk alkyl carbon contents of the sorbents, rather than aromatic carbon. Sorption of atrazine by these sorbents, however, is regulated by polar interactions (e.g., hydrogen bonding). Carboxylic and phenolic moieties are key components for H-bonding formation. Thermal analysis reveals that sorption of apolar (i.e., phenanthrene and lindane) and polar (i.e., atrazine) compounds by humic substances exhibit dissimilar relationships with condensation and thermal stability of sorption domains, emphasizing the major influence of domain spatial arrangement on sorption of organic compounds with distinct polarity. Results of pH-dependent sorption indicate that reduction in sorption of atrazine by the tested sorbents is more evident than phenanthrene with increasing pH, supporting the dependence of organic compound sorption on its polarity and structure. This study highlights the different interaction mechanisms of apolar and polar organic compounds with humic substances.

  2. A study of metal complexation with humic and fulvic acid: the effect of temperature on association and dissociation

    Energy Technology Data Exchange (ETDEWEB)

    King, S.J.; Warwick, P. [Loughborough Univ. of Technology (United Kingdom). Dept. of Chemistry; Bryan, N. [RMC Ltd., Abingdon (United Kingdom); Manchester Univ. (United Kingdom). Dept. of Chemistry

    1999-06-01

    The main objective of the project is to determine the influence of humic substances on the migration of radionuclides. One of the first steps taken in order to deepen this understanding was to investigate the complexation of Eu{sup 3+} and UO{sub 2}{sup 2+} with humic substances (Task 2). There is concern that after disposal in underground repositories radionuclides may eventually come into contact with groundwaters containing humic substances at elevated temperatures. Investigations have therefore been undertaken to determine the temperature dependence of the stability constants for europium and uranium binding to humic and fulvic acid by a series of batch experiments. The rate at which these complexes dissociate may be a significant factor in understanding the radionuclide transportation in the environment and has been investigated over a range of environmental parameters. The derived binding strengths, enthalpies and entropies of reaction and dissociation rate constants have been used for the mechanistic modelling of metal-humate interactions by Bryan et al in this volume. (orig.)

  3. Properties of the humic-like material arising from the photo-transformation of L-tyrosine

    Energy Technology Data Exchange (ETDEWEB)

    Berto, Silvia, E-mail: silvia.berto@unito.it [Università di Torino, Dipartimento Chimica, via P. Giuria, 7, 10125 Torino (Italy); De Laurentiis, Elisa; Tota, Tiziana; Chiavazza, Enrico; Daniele, Pier Giuseppe; Minella, Marco [Università di Torino, Dipartimento Chimica, via P. Giuria, 7, 10125 Torino (Italy); Isaia, Marco [Università di Torino, Dipartimento di Scienze della Vita e Biologia dei Sistemi, Via Accademia Albertina 13, Torino 10123 (Italy); Brigante, Marcello [Clermont Université, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, BP 10448, F-63000 Clermont-Ferrand (France); CNRS, UMR 6296, ICCF, BP 80026, F-63177 Aubière (France); Vione, Davide, E-mail: davide.vione@unito.it [Università di Torino, Dipartimento Chimica, via P. Giuria, 7, 10125 Torino (Italy)

    2016-03-01

    The UVB photolysis of L-tyrosine yields species with fluorescence and absorption spectra that are very similar to those of humic substances. By potentiometric measurements, chemical modeling and the application of NMR, mass spectrometry and laser flash photolysis, it was possible to get insights into the structural and chemical properties of the compounds derived by the L-tyrosine phototransformation. The photolytic process follows aromatic-ring hydroxylation and dimerization. The latter is presumably linked with the photoinduced generation of tyrosyl (phenoxy-type) radicals, which have a marked tendency to dimerize and possibly oligomerize. Interestingly, photoinduced transformation gives compounds with protogenic and complexation capabilities similar to those of the humic substances that occur naturally in surface waters. This finding substantiates a new and potentially important abiotic (photolytic) pathway for the formation of humic compounds in surface-water environments. - Highlights: • Tyrosine photolysis proceeds through deamination, hydroxylation and dimerization. • Dimerization could be linked to the photoinduced formation of tyrosyl radicals. • New protogenic sites are formed by irradiation, compared to the parent amino acid. • The irradiated material has higher copper complexation capacity than tyrosine. • Humic-like substances derived from tyrosine could complex Cu in surface waters.

  4. Prophylactic effects of humic acid AND#8211; glucan combination against experimental liver injury

    Directory of Open Access Journals (Sweden)

    Vaclav Vetvicka

    2015-09-01

    Full Text Available Aim: Despite intensive research, liver diseases represent a significant health problem and current medicine does not offer a substance able to significantly inhibit the hepatotoxicity leading to various stages of liver disease. Based on our previously published studies showing the protective effects of a glucan-humic acid combination, we focused on the hypothesis that combination of these two natural molecules can offer prophylactic protection against experimentally induced hepatotoxicity. Methods: lipopolysaccharide (LPS, carbon tetrachloride (CCl4 and ethanol were used to experimentally damage the liver. Levels of aspartate aminotransferase (AST, alanine transaminase (ALT, alkaline phosphatase (ALP, glutathione (GSH, superoxide dismutase (SOD and malondialdehyde (MDA, known to correspond to the liver damage, were assayed. Results: Using three different hepatotoxins, we found that in all cases, some samples of humic acid and most of all the glucan-humic acid combination, offer strong protection against liver damage. Conclusion: glucan-humic acid combination is a promising agent for use in liver protection. [J Intercult Ethnopharmacol 2015; 4(3.000: 249-255

  5. Separation of Gd-humic complexes and Gd-based magnetic resonance imaging contrast agent in river water with QAE-Sephadex A-25 for the fractionation analysis.

    Science.gov (United States)

    Matsumiya, Hiroaki; Inoue, Hiroto; Hiraide, Masataka

    2014-10-01

    Gadolinium complexed with naturally occurring, negatively charged humic substances (humic and fulvic acids) was collected from 500 mL of sample solution onto a column packed with 150 mg of a strongly basic anion-exchanger (QAE-Sephadex A-25). A Gd-based magnetic resonance imaging contrast agent (diethylenetriamine-N,N,N',N″,N″-pentaacetato aquo gadolinium(III), Gd-DTPA(2-)) was simultaneously collected on the same column. The Gd-DTPA complex was desorbed by anion-exchange with 50mM tetramethylammonium sulfate, leaving the Gd-humic complexes on the column. The Gd-humic complexes were subsequently dissociated with 1M nitric acid to desorb the humic fraction of Gd. The two-step desorption with small volumes of the eluting agents allowed the 100-fold preconcentration for the fractionation analysis of Gd at low ng L(-1) levels by inductively coupled plasma-mass spectrometry (ICP-MS). On the other hand, Gd(III) neither complexed with humic substances nor DTPA, i.e., free species, was not sorbed on the column. The free Gd in the effluent was preconcentrated 100-fold by a conventional solid-phase extraction with an iminodiacetic acid-type chelating resin and determined by ICP-MS. The proposed analytical fractionation method was applied to river water samples. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Geneva University - Particle Physics Seminars

    CERN Multimedia

    Université de Genève

    2010-01-01

    GENEVA UNIVERSITY École de physique Département de physique nucléaire et corspusculaire 24, quai Ernest-Ansermet 1211 GENÈVE 4 Tél. (022) 379 62 73 Fax: (022) 379 69 92 Wednesday 13 October 2010 PARTICLE PHYSICS SEMINAR at 17.00 hrs – Stückelberg Auditorium Exotic hadrons, Light Higgs and Dark Forces at BABAR Dr. Bertrand Echenard / California Institute of Technology From spectroscopy to search new physics, B-factories have explored many exciting topics besides establishing CP-violation in B decays. We will review recent results on spectroscopy, exotic hadrons and search for light Higgs. Current searches for dark forces and GeV-scale dark matter particles will also be discussed. Information : http://dpnc.unige.ch/seminaire/annonce.html Organizer : G. Pasztor Wednesday 20 October 2010 PARTICLE PHYSICS SEMINAR at 17.00 hrs – Stückelberg Auditorium The MINOS Experiment, Results and Future Plans Pro...

  7. PREPARATION FOR RETIREMENT - AVS SEMINAR

    CERN Multimedia

    Social Service

    2001-01-01

    The 500 or so participants in the fifth Preparation for Retirement seminar held at the end of March were unfortunately deprived of the planned session on the AVS due to the unavailability of the Director of the Caisse Cantonale Genevoise de Compensation (CCGC). We have since had formal confirmation that because of an extra workload due to important changes in the Swiss tax and social legislation and the implementation this summer of the maternity insurance in Geneva, the CCGC has suspended its participation in preparation for retirement seminars in the international organisations for the time being. Conscious of the necessity of offering a session dedicated to the AVS, it is with pleasure that we can inform you that one of our legal advisers, Mr Lorenz Stampfli, has accepted to lead this session. In order to allow for adequate preparation we have reserved the following date: Wednesday 26 September from 14.00 to 16.00 in the Main Amphitheatre The session will be open to all people already registered and any o...

  8. TECHNICAL TRAINING SEMINAR: National Instruments

    CERN Multimedia

    Monique Duval

    2004-01-01

    From 9:30 to 12:00 and from 13:00 to 16:00 hrs - Council Chamber, Salle B, Salle des Pas Perdus National Instruments (NI) on Tour 2004 Claudia Jüngel, Evrem Yarkin, Joel Clerc, Hervé Baour / NATIONAL INSTRUMENTS The special event NI on Tour 2004, run in Germany, Austria and Switzerland, will be at CERN on March 30. Technical seminars and free introductory courses will be offered all day long in the Council Chamber, Salle B, and Salle des Pas Perdus (buildings 61 and 503). Data acquisition systems on PCs, industrial measurement and control techniques, advanced LabVIEW software and PXI instrumentation, and system components for tests and automation will be presented. Walk-in courses will address DIAdem, LabVIEW and data acquisition. Language: English and French Free seminars and courses, no registration Organisers: Rolf Stampfli / IT-CO / 78102 & 160367 / Rolf.Stampfli@cern.ch Davide Vitè / HR-PMD-ATT / 75141 Davide.Vite@cern.ch For more information and the complete event programme, please visit the...

  9. Seminar

    African Journals Online (AJOL)

    abp

    8 mai 2015 ... Yamamoto T1, Ozono K, Kasayama S, Yoh K, Hiroshima K,. Takagi M, et al. Increased IL-6 production by cells isolated from the fibrous bone dysplasia tissues in patients with. McCune-Albright syndrome. J Clin Invest. 1996; 98:30-. 5. PubMed | Google Scholar. 10. Corsi A, Collins MT, Riminucci M, Howell ...

  10. Seminar

    African Journals Online (AJOL)

    abp

    incontinence anale peut être classée selon l'atteinte de l'une ou de l'autre des composantes sphinctérienne. Dans les différentes causes d'incontinence anale, ces lésions s'associent à des degrés divers. (rupture sphinctérienne ...

  11. Seminar

    African Journals Online (AJOL)

    abp

    borderline" breast lesions. Pathol Biol (Paris). 1990 Oct;38(8):776-7. PubMed | Google · Scholar. 6. Sickles EA. The subtle and atypical mammographic features of invasive lobular carcinoma. Radiology. 1991 Jan;178(1):25-6.

  12. Seminar

    African Journals Online (AJOL)

    abp

    6 mai 2014 ... sensible pour la mise en évidence de ces lésions et qui est devenue un examen de pratique courante dans le carcinome lobulaire du sein. ..... Joan E Etzell, Sandy Devries, Chew K, Florendo C, et al. Loss of. Chromosome 16q in Lobular Carcinoma In Situ. Human. Pathology. 2001 March; 32(3): 247-355.

  13. Seminar

    African Journals Online (AJOL)

    abp

    8 mai 2015 ... début de la prise en charge pour dépister l'ensemble des lésions osseuses de la DF, les lésions dysplasiques ... recommandations dans le diagnostic et la prise en charge de la DF. En générale, le diagnostic de la DF doit .... Page number not for citation purposes. 6 traitement de la polyarthrite rhumatoïde.

  14. Preparation of fulvic acid and low-molecular organic acids by oxidation of weathered coal humic acid

    Energy Technology Data Exchange (ETDEWEB)

    Shinozuka, T.; Ito, A.; Sasaki, O.; Yazawa, Y.; Yamaguchi, T. [Chiba Institute of Technolgy, Chiba (Japan). Dept. of Industrial Chemistry

    2002-07-01

    Weathered coal contains much humic acid and a little fulvic acid. Therefore, the production of fulvic acid, the most valuable humic substance because of its water-solubility, was examined by ozone and hydrogen peroxide oxidation of humic acid extracted form Xinjiang (China) weathered coal. The resulting products of the oxidation were water soluble fulvic acid and organic acids, mainly formic acid and oxalic acid. The product yield of fulvic acid was 20 (C%) and that of organic acids were 39 (C%) for formic and acid 13 (C%) for oxalic acid. The formed fulvic acid showed a higher content of oxygen and carboxyl groups, than those of the extracted one from the original weathered coal.

  15. Copper(II and lead(II complexation by humic acid and humic-like ligands

    Directory of Open Access Journals (Sweden)

    IVANA KOSTIĆ

    2011-09-01

    Full Text Available The stability of metal–humate complexes is an important factor determining and predicting speciation, mobility and bioavailability of heavy metals in the environment. A comparative investigation of the complexation of Cu(II and Pb(II with humic acid and humic-like ligands, such as benzoic and salicylic acid, was performed. The analysis was realized at pH 4.0, a temperature of 25 °C and at an ionic strength of 0.01 mol dm-3 (NaCl using the Schubert ion-exchange method and its modified form. The stability constants were calculated from the experimental data by the Schubert method for complexes with benzoic and humic acid. A modified Schubert method was used for the determination of the stability constants of the complexes with salicylic acid. It was found that Cu(II and Pb(II form mononuclear complexes with benzoic and humic acid while with salicylic acid both metals form polynuclear complexes. The results indicate that Pb(II has a higher binding ability than Cu(II to all the investigated ligands. The Cu(II–salicylate and Pb(II–salicylate complexes showed noticeable higher stability constants compared with their complexes with humic acid, while the stabilities of the complexes with benzoic acid differed less. Salicylic and benzoic acids as humic-like ligands can be used for setting the range of stability constants of humic complexes with Cu(II and Pb(II.

  16. Comparison of humic acids production by Trichoderma viride and ...

    African Journals Online (AJOL)

    The remarkable properties of humic acids have generated a broad spectrum of applications in pharmaceutical, cosmetic and agricultural fields, and encouraged fermentation studies focusing on humic acids production. This work compares the humic acids production of Trichoderma (viride and reesei) species using empty ...

  17. Spectral Study of Modified Humic Acids from Lignite

    Science.gov (United States)

    Zherebtsov, Sergey; Malyshenko, Natalya; Bryukhovetskaya, Ludmila; Ismagilov, Zinfer

    2017-11-01

    The IR-Fourier, ESR and solid-state 13C NMR analysis are used for investigation of unmodified and modified humic acids obtained from Tisul lignite (the Kansko-Achinsk Basin). Treatment with Hydrogen peroxide used for modification of humic acids and it changes the functionalgroup composition of the humic acids and increases the sorptional capacity

  18. Humic derivatives as promising hormone-like materials

    Science.gov (United States)

    Koroleva, R. P.; Khudaibergenova, E. M.; Kydralieva, K. A.; Jorobekova, Sh. J.

    2009-04-01

    The aim of this research is to prepare novel bio-inoculants derived from coal humic substances (HS) using bio-solubilization technique. This approach can be considered to some extent as model for supply plants with available nutrients throw the mineralisation of organic matter in soils by bacteria and fungi. Screening for the stable and active microorganisms' strains possessing ability to degrade humic substances was performed. The following subjects were examined using different isolation methods: natural microbial population from city soil, wood rot of Ulmis Pamila and biohumus of vermiculture of Eisenia foetida. Approaches for monitoring the humics-solubilizing fungi growth under liquid surface conditions in the presence of HS, proper conditions of bio-solubilization technique were elaborated. Coal humic acids (HA) from oxidized brown coal (Kyrgyz deposits) were isolated and added to a Czapek nutrient broth which was used either in full strength or without nitrogen source. The individual flasks were inoculated with natural microbial populations of corresponding cultivated soil, biohumus and wood rot samples for 12 months. Evaluation of phyto-hormonal activity of the produced HS and their derivatives in respect to higher plants with auxine and gibberellic tests was performed. To characterize structure of the biopreparations obtained, an experimental approach was undertaken that implies application of different complementary techniques for the structural analysis of biopreparations. As those were used: elemental and functional analysis, FTIR and 1H, 13C NMR spectroscopy and size-exclusion chromatography. According to the elemental composition of HS recovered from microbial cultures, a decrease in carbon and a significant increase of nitrogen in HS reisolated from the full strength broth inoculated with wood-decay microorganisms has been found. If biohumus microorganisms were used as inoculum, only minor changes were detected in the elemental composition of HS. A

  19. Induction Seminars as Professional Learning Communities for Beginning Teachers

    Science.gov (United States)

    Fresko, Barbara; Nasser-Abu Alhija, Fadia

    2015-01-01

    This paper explores the operation and contribution of induction seminars operated as learning communities for new teachers. Mixed methods were used: 378 new teachers and 29 seminar leaders completed questionnaires, 16 new teachers and 14 seminar leaders were interviewed, and 20 seminar meetings were observed. Findings showed that seminar…

  20. Increasing Effectiveness of Strategic Planning Seminars through Learning Style

    Science.gov (United States)

    Yildirim, Nail

    2010-01-01

    This research tests the effectiveness of taking learning style variables from the Kolb learning model in designing strategic planning seminars. We observe in our research that the participants in the seminar--school principals--positively judge the effectiveness of the seminar. The research also tests the seminar's effectiveness in terms of the…

  1. Discourse domination? The role of gender in seminar interaction ...

    African Journals Online (AJOL)

    This paper focuses on the effect of the gender of participants on the discourse patterns of university seminars, and compares the interaction patterns in two undergraduate seminars with those in two post-graduate seminars at Rhodes University. In the undergraduate seminars, two different groups of students at first year ...

  2. Quantitative evaluation of noncovalent interactions between polyphosphate and dissolved humic acids in aqueous conditions.

    Science.gov (United States)

    Fang, Wei; Sheng, Guo-Ping; Wang, Long-Fei; Ye, Xiao-Dong; Yu, Han-Qing

    2015-12-01

    As one kind of phosphorus species, polyphosphate (poly-P) is ubiquitous in natural environments, and the potential interactions between poly-P and humic substances in the sediments or natural waters would influence the fate of poly-P in the environments. However, the mechanism of the interactions has not yet been understood clearly. In this work, the characteristics and mechanisms of the interactions between humic acids (HA) and two model poly-P compounds with various chain lengths have been investigated. Results show that a stable polyphosphate-HA complex would be formed through the noncovalent interactions, and hydrogen bond might be the main driving force for the binding process, which might be formed between the proton-accepting groups of poly-P (e.g., PO and P-O(-)) and the oxygen containing functional groups in HA. Our findings implied that the presence of humic substances in natural waters, soils and sediments would influence the potential transport and/or mobility of environmental poly-P. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Iodine binding to humic acid.

    Science.gov (United States)

    Bowley, H E; Young, S D; Ander, E L; Crout, N M J; Watts, M J; Bailey, E H

    2016-08-01

    The rate of reactions between humic acid (HA) and iodide (I(-)) and iodate (IO3(-)) have been investigated in suspensions spiked with (129)I at concentrations of 22, 44 and 88 μg L(-1) and stored at 10 °C. Changes in the speciation of (129)I(-), (129)IO3(-) and mixed ((129)I(-) + (129)IO3(-)) spikes were monitored over 77 days using liquid chromatography inductively coupled plasma mass spectrometry (LC-ICP-MS). In suspensions spiked with (129)I(-) 25% of the added I(-) was transformed into organic iodine (Org-(129)I) within 77 days and there was no evidence of (129)IO3(-) formation. By contrast, rapid loss of (129)IO3(-) and increase in both (129)I(-) and Org-(129)I was observed in (129)IO3(-)-spiked suspensions. However, the rate of Org-(129)I production was greater in mixed systems compared to (129)IO3(-)-spiked suspensions with the same total (129)I concentration, possibly indicating IO3(-)I(-) redox coupling. Size exclusion chromatography (SEC) demonstrated that Org-(129)I was present in both high and low molecular weight fractions of the HA although a slight preference to bond with the lower molecular weight fractions was observed indicating that, after 77 days, the spiked isotope had not fully mixed with the native (127)I pool. Iodine transformations were modelled using first order rate equations and fitted rate coefficients determined. However, extrapolation of the model to 250 days indicated that a pseudo-steady state would be attained after ∼200 days but that the proportion of (129)I incorporated into HA was less than that of (127)I indicating the presence of a recalcitrant pool of (127)I that was unavailable for isotopic mixing. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Israel Seminar 2004-2005

    CERN Document Server

    Schechtman, Gideon

    2007-01-01

    This collection of original papers related to the Israeli GAFA seminar (on Geometric Aspects of Functional Analysis) during the years 2004-2005 follows the long tradition of the previous volumes that reflect the general trends of the Theory and are a source of inspiration for research. Most of the papers deal with different aspects of the Asymptotic Geometric Analysis, ranging from classical topics in the geometry of convex bodies, to inequalities involving volumes of such bodies or, more generally, log-concave measures, to the study of sections or projections of convex bodies. In many of the papers Probability Theory plays an important role; in some limit laws for measures associated with convex bodies, resembling Central Limit Theorems, are derive and in others probabilistic tools are used extensively. There are also papers on related subjects, including a survey on the behavior of the largest eigenvalue of random matrices and some topics in Number Theory.

  5. Israel Seminar 2014-2016

    CERN Document Server

    Milman, Emanuel

    2017-01-01

    As in the previous Seminar Notes, the current volume reflects general trends in the study of Geometric Aspects of Functional Analysis, understood in a broad sense. A classical theme in the Local Theory of Banach Spaces which is well represented in this volume is the identification of lower-dimensional structures in high-dimensional objects. More recent applications of high-dimensionality are manifested by contributions in Random Matrix Theory, Concentration of Measure and Empirical Processes. Naturally, the Gaussian measure plays a central role in many of these topics, and is also studied in this volume; in particular, the recent breakthrough proof of the Gaussian Correlation Conjecture is revisited. The interplay of the theory with Harmonic and Spectral Analysis is also well apparent in several contributions. The classical relation to both the primal and dual Brunn-Minkowski theories is also well represented, and related algebraic structures pertaining to valuations and valent functions are discussed. All co...

  6. Israel Seminar 2011-2013

    CERN Document Server

    Milman, Emanuel

    2014-01-01

    As in the previous Seminar Notes, the current volume reflects general trends in the study of Geometric Aspects of Functional Analysis. Most of the papers deal with different aspects of Asymptotic Geometric Analysis, understood in a broad sense; many continue the study of geometric and volumetric properties of convex bodies and log-concave measures in high-dimensions and in particular the mean-norm, mean-width, metric entropy, spectral-gap, thin-shell and slicing parameters, with applications to Dvoretzky and Central-Limit-type results. The study of spectral properties of various systems, matrices, operators and potentials is another central theme in this volume. As expected, probabilistic tools play a significant role and probabilistic questions regarding Gaussian noise stability, the Gaussian Free Field and First Passage Percolation are also addressed. The historical connection to the field of Classical Convexity is also well represented with new properties and applications of mixed-volumes. The interplay be...

  7. Israel Seminar 2006–2010

    CERN Document Server

    Mendelson, Shahar; Milman, Vitali

    2012-01-01

    This collection of original papers related to the Israeli GAFA seminar (on Geometric Aspects of Functional Analysis) from the years 2006 to 2011 continues the long tradition of the previous volumes, which reflect the general trends of Asymptotic Geometric Analysis, understood in a broad sense, and are a source of inspiration for new research. Most of the papers deal with various aspects of the theory, including classical topics in the geometry of convex bodies, inequalities involving volumes of such bodies or more generally, logarithmically-concave measures, valuation theory, probabilistic and isoperimetric problems in the combinatorial setting, volume distribution on high-dimensional spaces and characterization of classical constructions in Geometry and Analysis (like the Legendre and Fourier transforms, derivation and others). All the papers here are original research papers.

  8. Lectures Abandoned: Active Learning by Active Seminars

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak; Corry, Aino Vonge

    2012-01-01

    Traditional lecture-based courses are widely criticised for be- ing less eective in teaching. The question is of course what should replace the lectures and various active learning tech- niques have been suggested and studied. In this paper, we report on our experiences of redesigning a software ......- tive seminars as a replacement of traditional lectures, an activity template for the contents of active seminars, an ac- count on how storytelling supported the seminars, as well as reports on our and the students' experiences....

  9. Proceedings of the fifth NUCEF seminar

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-12-01

    The Fifth NUCEF Seminar was held at Tokai Research Establishment, JAERI on February 27, 2001. The NUCEF Seminar aims at the promotion of effective researches and encouragement of research cooperation through the discussions and information exchanges by researchers in the field of the nuclear fuel cycle back-end. This seminar was divided into the following sessions: TRU Chemistry, Radioactive Waste Management, Criticality Safety and Partitioning/Reprocessing. At the panel discussion, important issues connected with the safety research for radioactive waste management were discussed among five speakers from the relevant organization in Japan. The 36 of the presented papers are indexed individually. (J.P.N.)

  10. Metalion-humic acid nanoparticle interactions

    DEFF Research Database (Denmark)

    Town, Raewyn M.; van Leeuwen, Herman P.

    2016-01-01

    Purely Donnan type models for electrostatic binding by humic acid (HA) nanoparticles are shown to be physically incomplete. To describe the extent of ion binding by HA, such models need to invoke parameters that are not consistent with experimental observations. These disparate parameters include...... binding by humic acid nanoparticles. The extent of Ca2+-HA association can be adequately described solely in terms of electrostatics only, including counterion condensation in the intraparticulate double layer in addition to Donnan partitioning in the remainder of the particle body. The binding of Cd...

  11. MOBRAL--Seminario Interamericano de Educacion de Adultos (MOBRAL--Interamerican Seminar on Adult Education). Final Report.

    Science.gov (United States)

    Ministerio da Educacao e Cultura, Rio de Janeiro (Brazil). Movimento Brasileiro de Alfabetizacao.

    The report contains the substance of the MOBRAL (Movimento Brasileiro de Alfabetizacao)--Interamerican Seminar on Adult Education held in Rio de Janeiro from April 9th to 18th, 1973, for invited representatives from 21 Latin America and Caribbean countries. The object was to make a contribution to the collective task of identifying, defining, and…

  12. Effect of compost and humic acid in mobility and concentration of cadmium and chromium in soil and plant

    Directory of Open Access Journals (Sweden)

    A. Chaab

    2016-12-01

    Full Text Available The effect of compost and humic acid in mobility and concentration of cadmium and chromium in contaminated soil were investigated. Experiment was carried out with three levels of soil cadmium and chromium and two organic matters (compost and humic acid. The study was performed in a randomized complete block design with 3 replicates. Results indicated that application of organic substances enhanced movement of cadmium and chromium in soil column. Humic acid is more effective than compost on the mobility of cadmium and chromium in soil. Mobility of cadmium and chromium in the lower depths of soil column were increased. Cadmium and chromium concentration in shoots and roots enhanced due to increasing those concentration in soil and application of organic substances. Increase in cadmium in shoots can be attributed to the high mobility of this element in maize plant. Maize root chromium concentration was greater than shoot chromium concentration. Humic acid was more effective than compost as cadmium and chromium concentration in root and shoot was concerned. Low mobility of chromium in plant and accumulation of chromium in roots can be reasons of decreasing of chromium concentration in shoot of plant and its bioaccumulation.

  13. Phosphorus in chronosequence of burnt sugar cane in Brazilian cerrado: humic acid analysis by {sup 31}P NMR; Fosforo em cronossequencia de cana-de-acucar queimada no cerrado goiano: analise de acidos humicos por RMN de {sup 31}P

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, Celeste Q.; Pereira, Marcos G.; Garcia, Andreas C., E-mail: mgervasiopereira@gmail.com [Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropedica, RJ (Brazil). Dept. de Solos; Perin, Adriano; Gazolla, Paulo R. [Instituto Federal de Educacao, Ciencia e Tecnologia Goiano, Rio Verde, GO (Brazil); Gonzalez, Antonio P. [Universidade de Coruna, ES (Spain). Faculdad de Ciencias

    2013-10-01

    The aim of this study was to identify, with the use of {sup 31}P NMR spectroscopy, organic P species in humic acids (HA) in samples from Oxisol cultivated in chronosequence with sugar cane, pasture and Cerrado. The main forms of P-type found were orthophosphate, monoester-P (phosphate sugars) and P-diester (orthophosphate). The {sup 31}P NMR technique proved capable of identifying changes in the areas studied as a function of sugar cane burning time. In areas with 1 and 5 years of burnt cane, a decrease in recalcitrant organic P in humic acids indicated the need for use of P-humic substances for plant nutrition (author)

  14. Visits Service Launches New Seminar Series

    CERN Multimedia

    2001-01-01

    The CERN Visits Service is launching a new series of seminars for guides, and they are open to everyone. The series kicks off next week with a talk by Konrad Elsener on the CERN neutrinos to Gran Sasso, CNGS, project.

  15. Group Therapy Graduate Seminar: A Developmental Perspective.

    Science.gov (United States)

    Geller, Shulamit; Shadach, Eran

    2015-07-01

    Teaching group therapy is an essential aspect of graduate studies within the helping professions. Existing models discuss four basic elements required for such training: experience, observation, supervised practice, and theory. The present paper offers a model for a group therapy seminar based on these four elements and organized along developmental concepts. Clinical observations of 120 psychology students who participated in the seminar were gathered over a five-year period. Teaching techniques included supervised observation, fish-bowl, one-way mirror, and a final paper integrating theory and practice. The seminar enabled students to practice and to theorize about group processes, both as participants and as co-leaders. Seminar outcomes and conclusions are discussed.

  16. IFLA pimedate raamatukogude sektsiooni seminar / Marja Kivihall

    Index Scriptorium Estoniae

    Kivihall, Marja, 1975-

    2008-01-01

    27.-28. veebruaril 2008 toimus Horvaatia pealinnas Zagrebis IFLA pimedate raamatukogude sektsiooni ja DAISY Konsortsiumi seminar "Putting libraries for the blind and print disabled on the agenda", kus artikli autor Marja Kivihall esines ettekandega Eesti Pimedate Raamatukogust

  17. Computer Science Meets Ecology (Dagstuhl Seminar 17091)

    OpenAIRE

    Camps-Valls, Gustau; Hickler, Thomas; König-Ries, Birgitta

    2017-01-01

    This report summarizes the program and main outcomes of the Dagstuhl Seminar 17091 entitled ``Computer Science Meets Ecolog''. Ecology is a discipline that poses many challenging problems involving big data collection, provenance and integration, as well as difficulties in data analysis, prediction and understanding. All these issues are precisely the arena where computer science is concerned. The seminar motivation was rooted in the belief that ecology could largely benefit from modern compu...

  18. 2015 Cross-Domain Deterrence Seminar Bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Juarez, Anthony [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-02-04

    In November 2015, the Center for Global Security Research, NSO, and Global Security program jointly sponsored a seminar investigating questions related to cross-domain deterrence at Lawrence Livermore National Laboratory. At the seminar, experts were asked to moderate discussion based on the four topics below. For each of these topics, we have compiled a short list of literature that will help analysts develop a baseline understanding of the issue.

  19. Chemical and spectroscopic characteristics of humic acids

    NARCIS (Netherlands)

    Ferreira, F.; Vidal-Torrado, P.; Otero, X.L.; Buurman, P.

    2013-01-01

    To characterise soil humic acids (HAs) extracted from Spanish marshes formed under different vegetation types (Spartina maritima (GSp), Juncus maritimus (GJc), Phragmites australis (GPh), and Scirpus maritimus (VSc)), soil depths (0-20, 20-40 and 40-60 cm), physiographic position (low and high

  20. Seminars: didactic proposal for teaching Genetics

    Directory of Open Access Journals (Sweden)

    Cibele Marli Cação Paiva Gouvêa

    2015-12-01

    Full Text Available The aim of this work was to use seminars taught by a group of students of the Biological Sciences of the Federal University of Alfenas and compare with a group that did not taught seminars, showing that the strategy has contributed to the teaching/learning process of the first group, in addition to other skills. The seminars focused on topics from Genetics, were chosen, prepared and presented by students, under the guidance of the professor in charge of the discipline. The seminar presentations were opened to the entire academic community and were followed by discussion with the participants. The results of this study showed that students who presented the seminars have obtained better grades in Genetics than the students that have not presented the seminars, indicating better Genetics knowledge fixation, in addition to Genetics knowledge dissemination to the participant public. The action has promoted the development of skills such as the autonomy of thought and action, the ability to integrate new and old elements of the diverse knowledge areas, the group working and problem solving.

  1. Experimental Seminar on Nuclear Energy for Teachers

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-02-01

    `Experimental Seminar on Nuclear Energy for Teachers` was conducted and sponsored by the Science and Technology Agency. And in order to understand nuclear energy properly through lectures and experiments with good results inclass, the seminar carried out for teachers of high schools and junior high schools by the Nuclear Technology and Education Center (NuTEC), Japan Atomic Energy Research Institute in 1990 FY to 1997 FY. In this report, details of the seminars in the above period are described and No.1 to 17 of Communication Letters of Experimental Seminar on Nuclear Energy` started at 1992 FY are described also. These letters were prepared for attendant follow-up program. And programs of recent seminars, future`s seminars, impressions and comments from attendants, reports from actual classes and others are described in these letters and they are very useful for educational classes on nuclear energy by other teachers. Therefore contents of the letters are listed and easy to refer. A part of this educational task was transferred to the Radiation Application Development Association in 1997 FY and other parts were transferred in 1998 FY. (author)

  2. Humic Acid Complexation of Th, Hf and Zr in Ligand Competition Experiments: Metal Loading and Ph Effects

    Science.gov (United States)

    Stern, Jennifer C.; Foustoukos, Dionysis I.; Sonke, Jeroen E.; Salters, Vincent J. M.

    2014-01-01

    The mobility of metals in soils and subsurface aquifers is strongly affected by sorption and complexation with dissolved organic matter, oxyhydroxides, clay minerals, and inorganic ligands. Humic substances (HS) are organic macromolecules with functional groups that have a strong affinity for binding metals, such as actinides. Thorium, often studied as an analog for tetravalent actinides, has also been shown to strongly associate with dissolved and colloidal HS in natural waters. The effects of HS on the mobilization dynamics of actinides are of particular interest in risk assessment of nuclear waste repositories. Here, we present conditional equilibrium binding constants (Kc, MHA) of thorium, hafnium, and zirconium-humic acid complexes from ligand competition experiments using capillary electrophoresis coupled with ICP-MS (CE- ICP-MS). Equilibrium dialysis ligand exchange (EDLE) experiments using size exclusion via a 1000 Damembrane were also performed to validate the CE-ICP-MS analysis. Experiments were performed at pH 3.5-7 with solutions containing one tetravalent metal (Th, Hf, or Zr), Elliot soil humic acid (EHA) or Pahokee peat humic acid (PHA), and EDTA. CE-ICP-MS and EDLE experiments yielded nearly identical binding constants for the metal- humic acid complexes, indicating that both methods are appropriate for examining metal speciation at conditions lower than neutral pH. We find that tetravalent metals form strong complexes with humic acids, with Kc, MHA several orders of magnitude above REE-humic complexes. Experiments were conducted at a range of dissolved HA concentrations to examine the effect of [HA]/[Th] molar ratio on Kc, MHA. At low metal loading conditions (i.e. elevated [HA]/[Th] ratios) the ThHA binding constant reached values that were not affected by the relative abundance of humic acid and thorium. The importance of [HA]/[Th] molar ratios on constraining the equilibrium of MHA complexation is apparent when our estimated Kc, MHA values

  3. Comparison of Chemical Structure of Alginite Humic Acids Isolated with Two Different Procedures with Soil Humic Acids

    Directory of Open Access Journals (Sweden)

    Barančíková Gabriela

    2016-12-01

    Full Text Available The different origin of alginite and soil organic matter may be the reason of differences in their humic acids (HA chemical structure. One of the aims of this article is to compare the chemical composition of alginite HA and HA isolated from different soil types. Another aim of this article is to compare the chemical structure of humic acids of alginite isolated with two different procedures: modified IHSS (International Humic Substances Society method and simplified extraction method. The modified IHSS method was applied for the isolation of alginite and soil HA. To obtain sufficient amount of alginate HA for biological experiments, simplified extraction method suited for large volumes of HA was applied. The differences in elemental analysis and ash proportion in HA extracted by modified IHSS method (C = 35.4, H = 43 atomic%, ash content = 0.08% and simplified extraction method (C = 31, H = 31 atomic%, ash content = 7.42% can be caused by different concentration of extraction solution and also differences in purification of HA. The differences in chemical structure between alginate HA and HA isolated from different soil types according to the data of elemental analysis (C content of alginite HA = 35.4 atomic%, C content in soils HA = 38.2‒49.1 atomic% and 13C nuclear magnetic resonance (NMR spectra (degree of aromaticity of alginite HA = 24.4% and soil HA= 35.9‒53% were found. Results of 13C NMR show that the content of aromatic carbon was decreasing in the following order: Haplic Chernozem HA > Andic Cambisol HA > Haplic Cambisol HA > alginite HA. Based on the obtained results, it can be concluded that the differences in the chemical structure of alginite and soil HA can be explained by the difference in the origin of organic matter in alginite and soil samples. The source of organic matter in alginite is mainly type II kerogen from algae and that of soil is lignin and cellulose (type III kerogen of higher plants.

  4. Geneva University - Particle Physics seminar

    CERN Multimedia

    Université de Genève

    2011-01-01

    UNIVERSITE DE GENEVE Ecole de physique Département de physique nucléaire et corspusculaire 24, quai Ernest-Ansermet 1211 Geneva 4 Tel. (022) 379 62 73 Fax (022) 379 69 92 Wednesday 8 June 2011 PARTICLE PHYSICS SEMINAR at 17.00 hrs – Stückelberg Auditorium A Novel Experiment for the Search muon -> eee Prof. Andre Schoening, University of Heidelberg The absence of lepton-flavor changing processes, like the non-observation of the radiative decay mu -> e gamma, has been a miracle since the dawn of the Standard Model of Particle Physics and lead to the introduction of the concept of lepton family numbers. Several experiments in the last decade have shown clear evidence for neutrino oscillations. The neutrino mixing angles measured are known to be large. However, the discovery of lepton flavor violating (LFV) effects in the charged lepton sector is yet owing. After motivating the search for LFV in general I will discuss the physics potential of a search m...

  5. Technical Training: Technical Training Seminar

    CERN Multimedia

    2004-01-01

    TECHNICAL TRAINING Monique Duval tel. 74924 technical.training@cern.ch Tuesday 3 February 2004 From 09:00 to 13:30 - Training Centre Auditorium - bldg. 593, room 11 USB (Universal Serial Bus) CYPRESS Seminar Claudia Colombini, Field Application Engineer CYPRESS ActiveComp Electronic GmbH D-85077 MANCHING, Germany As a pioneer in USB, CYPRESS sets the standard for cost-effective solutions without sacrificing functionality, performance or reliability. Having shipped over 200 million USB devices, Cypress is the undisputed market leader and demonstrates unmatched USB expertise. With the industry's broadest selection of USB solutions, Cypress has the right silicon, software and support for every USB application, from Low-speed to High-Speed and USB On-The-Go (OTG). 9:00 - 10:30 Overview of USB systems. USB CYPRESS product overview. Peripherals: Low Speed, Full Speed, High Speed (1.1 and 2.0). Hub Solutions, Embedded Host Solutions, On-The-Go (OTG) and wireless USB. USB Development Tools (first part) 10:30 -...

  6. Balint seminars: the transatlantic experience through videoconference.

    Science.gov (United States)

    Antoun, Jumana; Romani, Maya; Johnson, Alan; Brock, Clive; Hamadeh, Ghassan

    2014-12-01

    The Balint seminar is used in many family medicine residencies to improve and strengthen the patient-doctor relationship: to make better doctors. Given the lack of Balint leaders in developing countries, the family medicine department at the American University of Beirut (AUB) decided to collaborate with the Medical University of South Carolina (MUSC)-with more than 30 years of experience-to start Balint seminars through videoconferencing. Evaluate the feasibility and effectiveness of Balint seminars conducted through videoconference. A qualitative research using focus group and leaders' feedback to evaluate feasibility of delivery of Balint seminars through videoconference. A Polycom videoconference was set up between residents at AUB and two credentialed Balint leaders at MUSC. The videoconference was composed of two parts: (i) MUSC faculty facilitating Balint seminars; and (ii) MUSC and AUB faculty debriefing following each Balint session. Twenty-six videoconferences were conducted from 15 February 2013 to 31 March 2014. Four themes emerged: technology and connectivity issues, administrative issues, coordination among different time zones and cultural/contextual issues. The videoconferencing with family medicine residents at AUB seemed quite natural and very familiar to the Balint leaders at MUSC. The seminars encouraged the residents to see things from the patients' perspective, inspiring new thoughts and ideas on how to deal with troubling patients. Videoconference Balint seminars offer a promising way to extend the activity to health care providers in other disciplines, states and countries. Moreover, this format has the potential to increase the number of trained Balint leaders. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  7. Effect of Coated Urea with Humic-Calcium on Transformation of Nitrogen in Coastal Sandy Soil: A Soil Column Method

    Directory of Open Access Journals (Sweden)

    Sulakhudin

    2010-01-01

    Full Text Available Effect of Coated Urea with Humic-Calcium on Transformation of Nitrogen in Coastal Sandy Soil: A Soil ColumnMethod (Sulakhudin, A Syukur, D Shiddieq and T Yuwono: In coastal sandy soil, mainly nitrogen losses due toleaching resulted to low fertilizer efficiency. Slow-release N fertilizers are proposed to minimize these losses, andhumic-calcium coated urea has been examined. A soil column method was used to compare the effects of coated ureawith humic-calcium on transformation and leaching loss of N in coastal sandy soil. The experiment aid to compare twokinds sources of humic substances (cow manure and peat which mixed with calcium as coated urea on transformation,vertical distribution and leaching N in coastal sandy soil. The concentration of humic-calcium coated urea i.e.1%, 5%and 10% based on their weight. The results showed that urea coated with humic-calcium from cow manure (UCHMand humic-calcium from peat (UCHP increased the N total and available N in the soil and decreased leaching loss ofN from the soil column. Compared to UCHP, UCHM in all concentration showed N-nitrate higher than N-ammonium onincubation length 2, 4 and 6 weeks. The N leached from a costal sandy soil with application coated urea with UCHMranged from 21.18% to 23.72% of the total N added as fertilizer, for coated urea with UCHP they ranged between21.44% and 23.25%, whereas for urea (control reached 29.48%. Leaching losses of mineral N were lower when ureacoated with UCHM compared to urea coated with UCHP or urea fertilizer. The study concluded that the UCHM isbetter than UCHP in decreasing N leached from coastal sandy soil

  8. Freshman Seminars: Interdisciplinary Engagements in Astronomy

    Science.gov (United States)

    Hemenway, M. K.

    2006-08-01

    The Freshman Seminar program at the University of Texas is designed to allow groups of fifteen students an engaging introduction to the University. The seminars introduce students to the resources of the university and allow them to identify interesting subjects for further research or future careers. An emphasis on oral and written communication by the students provides these first-year students a transition to college-level writing and thinking. Seminar activities include field trips to an art museum, a research library, and the Humanities Research Center rare book collection. This paper will report on two seminars, each fifteen weeks in length. In "The Galileo Scandal" students examine Galileo's struggle with the church (including a mock trial). They perform activities that connect his use of the telescope and observations to astronomical concepts. In "Astronomy and the Humanities" students analyze various forms of human expression that have astronomical connections (art, drama, literature, music, poetry, and science fiction); they perform hands-on activities to reinforce the related astronomy concepts. Evaluation of the seminars indicates student engagement and improvement in communication skills. Many of the activities could be used independently to engage students enrolled in standard introductory astronomy classes.

  9. Conductivity-Dependent Flow Field-Flow Fractionation of Fulvic and Humic Acid Aggregates

    Directory of Open Access Journals (Sweden)

    Martha J. M. Wells

    2015-09-01

    Full Text Available Fulvic (FAs and humic acids (HAs are chemically fascinating. In water, they have a strong propensity to aggregate, but this research reveals that tendency is regulated by ionic strength. In the environment, conductivity extremes occur naturally—freshwater to seawater—warranting consideration at low and high values. The flow field flow fractionation (flow FFF of FAs and HAs is observed to be concentration dependent in low ionic strength solutions whereas the corresponding flow FFF fractograms in high ionic strength solutions are concentration independent. Dynamic light scattering (DLS also reveals insight into the conductivity-dependent behavior of humic substances (HSs. Four particle size ranges for FAs and humic acid aggregates are examined: (1 <10 nm; (2 10 nm–6 µm; (3 6–100 µm; and (4 >100 µm. Representative components of the different size ranges are observed to dynamically coexist in solution. The character of the various aggregates observed—such as random-extended-coiled macromolecules, hydrogels, supramolecular, and micellar—as influenced by electrolytic conductivity, is discussed. The disaggregation/aggregation of HSs is proposed to be a dynamic equilibrium process for which the rate of aggregate formation is controlled by the electrolytic conductivity of the solution.

  10. Nanoparticle-assisted photo-Fenton reaction for photo-decomposition of humic acid

    Science.gov (United States)

    Banik, Jhuma; Basumallick, Srijita

    2017-11-01

    We report here the synthesis of CuO-doped ZnO composite nanomaterials (NMs) by chemical route and demonstrated for the first time that these NMs are efficient catalysts for H2O2-assisted photo-decomposition (photo-Fenton type catalyst) of humic acid, a natural pollutant of surface water by solar irradiation. This has been explained by faster electron transfer to OH radical at the p-n hetero-junction of this composite catalyst. Application of this composite catalyst in decomposing humus substances of local pond water by solar energy has been demonstrated.

  11. Adsorption of humic acid from landfill leachate by nitrogen-containing activated carbon

    Science.gov (United States)

    Qin, Hangdao; Meng, Jianling; Chen, Jing

    2017-01-01

    Humic substances are the major contaminants in the landfill leachate, while activated carbon adsorption is an effective treatment method. AC was modified with nitric acid, ammonium hydroxide and urea, which introduced functional groups onto AC surface. The adsorption capacity of HA on AC were investigated. ACN showed the highest HA adsorption capacity, increasing more than 20% compared to the parent one. The results indicated that the mesoporous structure favored HA adsorption and the nitrogen-containing basic groups played an important role in the adsorption of HA.

  12. Action of humic acid on promotion of cucumber shoot growth involves nitrate-related changes associated with the root-to-shoot distribution of cytokinins, polyamines and mineral nutrients.

    Science.gov (United States)

    Mora, Verónica; Bacaicoa, Eva; Zamarreño, Angel-Maria; Aguirre, Elena; Garnica, Maria; Fuentes, Marta; García-Mina, José-Maria

    2010-05-15

    Numerous studies have reported the ability of humic substances to increase shoot growth in different plant species cultivated under diverse growth conditions. However, the mechanism responsible for this effect of humic substances is poorly understood. It is possible that the shoot promoting effect of humic substances involves a primary effect on root H(+)-ATPase activity and nitrate root-shoot distribution that, in turn, causes changes in the root-shoot distribution of certain cytokinins, polyamines and abscisic acid, thus affecting shoot growth. We investigated this hypothesis in the present study. The results showed that the root application of a purified humic acid causes a significant increase in shoot growth that is associated with an enhancement in root H(+)-ATPase activity, an increase in nitrate shoot concentration, and a decrease in roots. These effects were associated with significant increases in the shoot concentration of several cytokinins and polyamines (principally putrescine), concomitant with decreases in roots. Likewise, these changes in the root-shoot distribution of diverse active cytokinins correlated well to significant changes in the root-shoot distribution of several mineral nutrients. These results, taken together, indicate that the beneficial effects of humic substances on shoot development in cucumber could be directly associated with nitrate-related effects on the shoot concentration of several active cytokinins and polyamines (principally putrescine). (c) 2010 Elsevier GmbH. All rights reserved.

  13. Metalion-humic acid nanoparticle interactions

    OpenAIRE

    Town, Raewyn M.; Leeuwen, van, M.G.A.

    2016-01-01

    Purely Donnan type models for electrostatic binding by humic acid (HA) nanoparticles are shown to be physically incomplete. To describe the extent of ion binding by HA, such models need to invoke parameters that are not consistent with experimental observations. These disparate parameters include anomalously high Donnan potentials, as well as intrinsic affinity constants for electrostatically associating ions such as Ca2+. In contrast, the recently introduced counterion condensation-Donnan mo...

  14. Coating of AFM probes with aquatic humic and non-humic NOM to study their adhesion properties.

    Science.gov (United States)

    Aubry, Cyril; Gutierrez, Leonardo; Croue, Jean Philippe

    2013-06-01

    Atomic force microscopy (AFM) was used to study interaction forces between four Natural Organic Matter (NOM) samples of different physicochemical characteristics and origins and mica surface at a wide range of ionic strength. All NOM samples were strongly adsorbed on positively charged iron oxide-coated silica colloidal probe. Cross-sectioning by focused ion beam milling technique and elemental mapping by energy-filtered transmission electron microscopy indicated coating completeness of the NOM-coated colloidal probes. AFM-generated force-distance curves were analyzed to elucidate the nature and mechanisms of these interacting forces. Electrostatics and steric interactions were important contributors to repulsive forces during approach, although the latter became more influential with increasing ionic strength. Retracting force profiles showed a NOM adhesion behavior on mica consistent with its physicochemical characteristics. Humic-like substances, referred as the least hydrophilic NOM fraction, i.e., so called hydrophobic NOM, poorly adsorbed on hydrophilic mica due to their high content of ionized carboxyl groups and aromatic/hydrophobic character. However, adhesion force increased with increasing ionic strength, suggesting double layer compression. Conversely, polysaccharide-like substances showed high adhesion to mica. Hydrogen-bonding between hydroxyl groups on polysaccharide-like substances and highly electronegative elements on mica was suggested as the main adsorption mechanism, where the adhesion force decreased with increasing ionic strength. Results from this investigation indicated that all NOM samples retained their characteristics after the coating procedure. The experimental approach followed in this study can potentially be extended to investigate interactions between NOM and clean or fouled membranes as a function of NOM physicochemical characteristics and solution chemistry. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Coating of AFM probes with aquatic humic and non-humic NOM to study their adhesion properties

    KAUST Repository

    Aubry, Cyril

    2013-06-01

    Atomic force microscopy (AFM) was used to study interaction forces between four Natural Organic Matter (NOM) samples of different physicochemical characteristics and origins and mica surface at a wide range of ionic strength. All NOM samples were strongly adsorbed on positively charged iron oxide-coated silica colloidal probe. Cross-sectioning by focused ion beam milling technique and elemental mapping by energy-filtered transmission electron microscopy indicated coating completeness of the NOM-coated colloidal probes. AFM-generated force-distance curves were analyzed to elucidate the nature and mechanisms of these interacting forces. Electrostatics and steric interactions were important contributors to repulsive forces during approach, although the latter became more influential with increasing ionic strength. Retracting force profiles showed a NOM adhesion behavior on mica consistent with its physicochemical characteristics. Humic-like substances, referred as the least hydrophilic NOM fraction, i.e., so called hydrophobic NOM, poorly adsorbed on hydrophilic mica due to their high content of ionized carboxyl groups and aromatic/hydrophobic character. However, adhesion force increased with increasing ionic strength, suggesting double layer compression. Conversely, polysaccharide-like substances showed high adhesion to mica. Hydrogen-bonding between hydroxyl groups on polysaccharide-like substances and highly electronegative elements on mica was suggested as the main adsorption mechanism, where the adhesion force decreased with increasing ionic strength. Results from this investigation indicated that all NOM samples retained their characteristics after the coating procedure. The experimental approach followed in this study can potentially be extended to investigate interactions between NOM and clean or fouled membranes as a function of NOM physicochemical characteristics and solution chemistry. © 2013 Elsevier Ltd.

  16. 19th International Seminar on High Energy Physics

    CERN Document Server

    2016-01-01

    "Quarks-2016" is the nineteenth in the series of seminars taking place biennially since 1980 in the Soviet Union and since 1992 in various historical and cultural places of Russia; the previous seminar, "Quarks-2014", was held in Suzdal.

  17. PROGRAMME OF SEMINARS MARCH TO JUNE 2004

    CERN Multimedia

    Nathalie Dumeaux

    2004-01-01

    Situation : 09.03.2004 Dates Days Places Available* Bilingual seminars Communication Techniques-1 16, 17, 18 March 3 no Project Management 17, 18, 19 March 3 yes Introduction to Management 23, 24, 25 March 3 yes Communication Techniques-1 8, 9, 10 June 3 yes Quality Management 5, 6, 7 may 3 yes Introduction to Management - Follow-up 22, 23 June 1,5 yes Seminars in English Making Presentations 22, 23 March & 1 April 3 yes Stress Management 22, 23 April 2 yes Chairing or participating in meetings 11, 12, 13 May 3 yes *If you are interested in a seminar where there are no places available, please fill in an application form and we will contact you as soon as a new session is organised. MANAGEMENT & COMMUNICATION Nathalie Dumeaux tel. 781 44 management.communication@cern.ch

  18. Reliability centered maintenance mini-seminar

    Energy Technology Data Exchange (ETDEWEB)

    Laakso, K.; Simola, K. (eds.) [VTT Automation, Espoo (Finland)

    2000-10-01

    In the Earlier NKS-project RAK-1 (1994-1997), the sub-project RAK-1.4, 'Maintenance Strategies and Ageing' focused on development of methodologies and tools for improving maintenance strategies. In the NKS/SOS-2 project (1998-2001), the maintenance related Nordic co-operation is continued. For exchange of information and as background and for discussions related to maintenance decisions in the NKS/SOS-2 project, a mini-seminar on maintenance strategies with an emphasis on reliability centred maintenance (RCM) approaches was arranged 14.10.1999. The report summarises the topics of the presentations and discussions at the seminar. The transparencies presented at the mini-seminar are enclosed in this report. (au)

  19. Effects of standard humic materials on relative bioavailability of NDL-PCBs in juvenile swine.

    Directory of Open Access Journals (Sweden)

    Matthieu Delannoy

    Full Text Available Young children with their hand-to-mouth activity may be exposed to contaminated soils. However few studies assessing exposure of organic compounds sequestrated in soil were realized. The present study explores the impact of different organic matters on retention of NDL-PCBs during digestive processes using commercial humic substances in a close digestive model of children: the piglet. Six artificial soils were used. One standard soil, devoid of organic matter, and five amended versions of this standard soil with either fulvic acid, humic acid, Sphagnum peat, activated carbon or a mix of Sphagnum peat and activated carbon (95∶5 (SPAC were prepared. In order to compare the different treatments, we use spiked oil and negative control animals. Forty male piglets were randomly distributed in 7 contaminated and one control groups (n = 5 for each group. During 10 days, the piglets were fed artificial soil or a corn oil spiked with 19,200 ng of Aroclor 1254 per g of dry matter (6,000 ng.g⁻¹ of NDL-PCBs to achieve an exposure dose of 1,200 ng NDL-PCBs.Kg⁻¹ of body weight per day. NDL-PCBs in adipose tissue were analyzed by GC-MS. Fulvic acid reduced slightly the bioavailability of NDL-PCBs compared to oil. Humic acid and Sphagnum peat reduced it significantly higher whereas activated carbon reduced the most. Piglets exposed to soil containing both activated carbon and Shagnum peat exhibited a lower reduction than soil with only activated carbon. Therefore, treatment groups are ordered by decreasing value of relative bioavailability as following: oil ≥ fulvic acid>Sphagnum peat ≥ Sphagnum peat and activated carbon ≥ Humic acid>>activated carbon. This suggests competition between Sphagnum peat and activated carbon. The present study highlights that quality of organic matter does have a significant effect on bioavailability of sequestrated organic compounds.

  20. L. D. Faddeev's seminar on mathematical physics

    CERN Document Server

    Semenov-Tian-Shansky, Michael

    2000-01-01

    Professor L. D. Faddeev's seminar at Steklov Mathematical Institute (St. Petersburg, Russia) has a record of more than 30 years of intensive work which has helped to shape modern mathematical physics. This collection, honoring Professor Faddeev's 65th anniversary, has been prepared by his students and colleagues. Topics covered in the volume include classical and quantum integrable systems (both analytic and algebraic aspects), quantum groups and generalizations, quantum field theory, and deformation quantization. Included is a history of the seminar highlighting important developments, such a

  1. Seminar Users in the Arabic Twitter Sphere

    OpenAIRE

    Darwish, Kareem; Alexandrov, Dimitar; Nakov, Preslav; Mejova, Yelena

    2017-01-01

    We introduce the notion of "seminar users", who are social media users engaged in propaganda in support of a political entity. We develop a framework that can identify such users with 84.4% precision and 76.1% recall. While our dataset is from the Arab region, omitting language-specific features has only a minor impact on classification performance, and thus, our approach could work for detecting seminar users in other parts of the world and in other languages. We further explored a controver...

  2. X International Poultry ASPA Seminar 2012

    Directory of Open Access Journals (Sweden)

    Fabio Cárdenas

    2012-06-01

    Full Text Available On 30, May 31 and June 1, 2012 was held the X International Poultry seminar held at the convention center Julio Cesar Turbay Ayala city of Cartagena de Indias, an event which is organized every year by the association Santander academic avian pathology (ASPA, within the framework of the celebration of the 30th anniversary of its official establishment as a partnership, where the directives made ​​in recognition of the principals who have gone through the association and launched the magazine "fuss "make it count and illustration of their history, creation, boards, regional and international seminars have been conducted and also pay homage to the deceased members.

  3. Fourth international seminar on horizontal steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Tuomisto, H. [ed.] [IVO Group, Vantaa (Finland); Purhonen, H. [ed.] [VTT, Espoo (Finland); Kouhia, V. [ed.] [Lappeenranta Univ. of Technology (Finland)

    1997-12-31

    The general objective of the International Seminars of Horizontal Steam Generator Modelling has been the improvement in understanding of realistic thermal hydraulic behaviour of the generators when performing safety analyses for VVER reactors. The main topics presented in the fourth seminar were: thermal hydraulic experiments and analyses, primary collector integrity, feedwater distributor replacement, management of primary-to-secondary leakage accidents and new developments in the VVER safety technology. The number of participants, representing designers and manufacturers of the horizontal steam generators, plant operators, engineering companies, research organizations, universities and regulatory authorities, was 70 from 10 countries.

  4. Copper(II) and lead(II) complexation by humic acid and humic-like ligands

    OpenAIRE

    IVANA KOSTIĆ; TATJANA ANĐELKOVIĆ; RUŽICA NIKOLIĆ; ALEKSANDAR BOJIĆ; MILOVAN PURENOVIĆ; SRĐAN BLAGOJEVIĆ; DARKO ANĐELKOVIĆ

    2011-01-01

    The stability of metal–humate complexes is an important factor determining and predicting speciation, mobility and bioavailability of heavy metals in the environment. A comparative investigation of the complexation of Cu(II) and Pb(II) with humic acid and humic-like ligands, such as benzoic and salicylic acid, was performed. The analysis was realized at pH 4.0, a temperature of 25 °C and at an ionic strength of 0.01 mol dm-3 (NaCl) using the Schubert ion-exchange method and its modified form....

  5. Seminar for Master's Thesis Projects: Promoting Students' Self-Regulation

    Science.gov (United States)

    Miedijensky, Shirley; Lichtinger, Einat

    2016-01-01

    This study presents a thesis seminar model aimed at promoting students' self-regulation. Students' perceptions regarding the contribution of the seminar to their learning process were characterized and the seminar's effect upon their self-regulation expressions was examined. Data was collected using questionnaires and analyzed thematically. The…

  6. (Eds.). Resource-bounded problem solving (Dagstuhl Seminar 14341)

    NARCIS (Netherlands)

    Haxhimusa, Y.; Rooij, I.J.E.I. van; Varma, S.; Wareham, H.T.

    2014-01-01

    This report documents the program and the outcomes of Dagstuhl Seminar 14341 'Resource-bounded Problem Solving'. This seminar is a successor to Dagstuhl Seminar 11351: 'Computer Science & Problem Solving: New Foundations', held in August 2011, which was the first Dagstuhl event to bring together

  7. Effect of humic acid on sorption of technetium by alumina

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S.; Rawat, N.; Kar, A.S. [Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085, Maharastra (India); Tomar, B.S., E-mail: bstomar@barc.gov.in [Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085, Maharastra (India); Manchanda, V.K. [Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085, Maharastra (India)

    2011-09-15

    Highlights: {yields} Tc sorption on alumina has been studied under aerobic as well anaerobic condition over pH 3-10. {yields} Effect of humic acid on sorption of Tc by alumina has been investigated. {yields} Linear additive modeling and surface complexation modeling were carried out to delineate the role of humic acid in Tc(IV) sorption in ternary system of Tc(IV)-humic acid-alumina. {yields} Sorption of humic acid onto alumina and strong complexation of Tc(IV) with humic acid were found to govern the sorption of Tc(IV) in the ternary system. - Abstract: Sorption of technetium by alumina has been studied in absence as well as in presence of humic acid using {sup 95}Tc{sup m} as a tracer. Measurements were carried out at fixed ionic strength (0.1 M NaClO{sub 4}) under varying pH (3-10) as well as redox (aerobic and reducing anaerobic) conditions. Under aerobic conditions, negligible sorption of technetium was observed onto alumina both in absence and in presence of humic acid. However, under reducing conditions (simulated with [Sn(II)] = 10{sup -6} M), presence of humic acid enhanced the sorption of technetium in the low pH region significantly and decreased at higher pH with respect to that in absence of humic acid. Linear additive as well as surface complexation modeling of Tc(IV) sorption in presence of humic acid indicated the predominant role of sorbed humic acid in deciding technetium sorption onto alumina.

  8. Humic First Theory: A New Theory on the Origin of Life

    Science.gov (United States)

    Daei, Mohammad Ali; Daei, Manijeh; Daei, Bijan

    2017-04-01

    organic matter like modern "humic substances" could perform this great and complicated duty. A mass of warm, wet clay mixed with enough humic substances (HS) in suitable PH, could provide all above requirements, and promote biochemical evolution step by step toward a functional primitive cell. HS are fluorescent compounds and could transform UV radiation to usable light. In addition these protective materials could provide chemical energy plus balanced minerals and organic molecules. While everything in non living world is reducing energy, HS can collect more and more material and energy like a living organism. Fortunately, there are reliable evidences that HS could be accessible on ancient Earth. In fact Ziechman et al [7], in 1994 by finding humic material in Miller's experimental vessels proved that humic substances could be generated on early Earth conditions by polymerizing simple organic molecules. Our investigations show elemental selection and also chairal selection for life are proportionately tailored to Humic materials. For example nearly all heavy metals make insoluble compounds with HS, hence omitted from life processes. In contrast all essential elements have appropriate affinity and workability with HS. There is reliable evidence that shows HS prefer left amino acids and right sugars. As you see many signs and symptoms are referring to "humic substances" as the mother of life, at least on this planet.

  9. Formação de subprodutos orgânicos halogenados nas operações de pré-oxidação com cloro, ozônio e peroxônio e pós-cloração em água conténdo subtância húmica Formation of halogenated organic byproducts using preoxidation with chlorine, ozone and peroxone and post-chlorination of water containing humic substances

    Directory of Open Access Journals (Sweden)

    Cristina Filomena Pereira Rosa Paschoalato

    2008-09-01

    Full Text Available Dentre os compostos orgânicos halogenados que podem ser encontrados na água distribuída à população, destacam-se: trialometanos, ácidos haloacéticos, haloaldeídos, halocetonas, halofenóis e halopicrinas. O presente trabalho teve como objetivo avaliar o efeito da formação de 22 subprodutos com a utilização dos pré-oxidantes: cloro, ozônio e peroxônio. A formação de subprodutos foi observada em água preparada com adição de substâncias húmicas extraídas de solo turfoso, por meio do uso da pré-oxidação, presença e ausência de coagulação, filtração e pós-cloração. Os subprodutos foram quantificados por cromatografia gasosa com detetor de captura de elétrons. Os resultados obtidos mostraram que o uso de pré-oxidantes alternativos, ozônio e peroxônio, associados à coagulação, filtração e pós-cloração, formam quantidades pequenas de subprodutos.When chlorine is used as preoxidant, the formation of halogenated organic byproducts found in water treated and distriduted to the population, are: trihalometane, haloacetic acids, haloaldehyde, haloketone, halophenol and halopicrin. This research was performed to evaluate the formation potential of 22 byproducts using the following preoxidants: chlorine, ozone and peroxone. The formation of byproducts was simulated in water prepared with the addition of humic substances extracted from peat soil by the use of preoxidants, coagulation, filtration, and post-chlorination. Byproducts have quantified by gas chromatography with electron capture detector. The results obtained showed that the use of alternative preoxidants, such as ozone and peroxone, associated with coagulation, filtration, and post-chlorination form a low concentration of byproducts.

  10. REMINDER PREPARATION FOR RETIREMENT PROGRAMME - AVS SEMINAR

    CERN Multimedia

    Social Service

    2001-01-01

    The AVS seminar, which had to be cancelled in March this year, will be held on: Wednesday 26 September from 14:00 to 16:00 in the Main Amphitheatre The session will be led by Mr. Lorenz STAMPFLI. The session is open to all people already registered and any other person who is interested, without the need to register.

  11. REMINDER Preparation for Retirement Programme - AVS Seminar

    CERN Multimedia

    Social Service

    2001-01-01

    The AVS seminar, which had to be cancelled in March this year, will be held on: Wednesday 26 September from 14:00 to 16:00 in the Main Amphitheatre The session will be led by Mr. Lorenz STAMPFLI. The session is open to all people already registered and any other person who is interested, without the need to register.

  12. Third international seminar on horizontal steam generators

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    The Third International Seminar on Horizontal Steam Generators held on October 18-20, 1994 in Lappeenranta, consisted of six sessions dealing with the topics: thermal hydraulic experiments and analyses, primary collector integrity, management of primary-to-secondary leakage accidents, feedwater collector replacement and discussion of VVER-440 steam generator safety issues.

  13. Video Conferencing for a Virtual Seminar Room

    DEFF Research Database (Denmark)

    Forchhammer, Søren; Fosgerau, A.; Hansen, Peter Søren K.

    2002-01-01

    A PC-based video conferencing system for a virtual seminar room is presented. The platform is enhanced with DSPs for audio and video coding and processing. A microphone array is used to facilitate audio based speaker tracking, which is used for adaptive beam-forming and automatic camera-control...

  14. Aggregates dynamic in contrasting soils with different fertilizations and role of humic carbon as binding agent

    Science.gov (United States)

    Lugato, E.; Simonetti, G.; Nardi, S.; Berti, A.; Giardini, L.; Morari, F.

    2009-04-01

    In the last years aggregates fractionation has become a very common approach to study the close linkage between aggregate formation and SOM turnover. According to the hierarchical theory microaggregates are assumed to be stabilized by persisting binding agents whereas macroaggregates by transient or temporary organic materials. Humic substances, considered to be recalcitrant, should likely act as persistent binding agents but their role, also because of their heterogeneity and discussed origin, is still unclear. In a long-term experiment established in the early 1960s in north-eastern Italy, we wet-sieved large macroaggregates to separate three aggregate sizes (2000-250 mm, 250-53 mm and clay, sandy and peaty), fertilized with manure and mineral fertilizers. We analysed organic (OC) and humic (HC) carbon of each aggregate fraction, also investigating the molecular weight of the humic substances extracted (>60 KDa,60-30 KDa, organic matter distribution and investigate the composition and role of HC as binding agent. The results evidenced that the addition of manure significantly increased the proportion of macroaggregates respect to the mineral fertilization but only in the clay soil. Aggregate hierarchy, according to which SOC concentration increase with increasing aggregates size, was generally supported by our data. The HC values followed the same pattern of the OC, with a very high correlation between these parameters (r >0.95). The HC/OC ratio, ranging narrowly among the aggregates fractions, indicated no hierarchical role of HC as persisting binding agents. However HC extracted in the silt-clay fraction showed higher proportion of low molecular weight fraction in peaty and clay soil, respect to HC of larger aggregates.

  15. Trace metals in humic acids and their hydrolysis products

    Energy Technology Data Exchange (ETDEWEB)

    Huljev, D.J.

    1986-04-01

    The role of humic acids in the transport of trace elements in the Sava river biocycle (near Zagreb, Yugoslavia) has been investigated by means of neutron activation analysis. Humic acids can accumulate certain trace elements, but little is known about their selectivity under certain physicochemical conditions. Humic acids isolated from Sava river sediments were hydrolized to their main components, namely to amino acids (proteins), phenols (and phenolic acids), carbohydrates, polycyclic aromatics, and metals. Degradation of humic acids in the environment occurs by the action of microorganisms, and during this step, certain trace metals become available to Sava river animals through standard physiological processes. In this work neutron activation analysis was applied to the quantitative and qualitative determination of trace metals in humic acids of Sava river origin, and in their hydrolysis products. The trace metals measured were Ag, Fe, Co, Cs, Eu, Sb, Sc, Se, and Sr. The concentrations obtained ranged from 0.05 to 2730 ..mu..g of a certain microconstituent per gram of sample. The experimental data are compared with laboratory experiments on the determination of stability constants for metal complexes of humic acids and their hydrolysis product. From these data it is possible to suggest the ecological importance of trace metals bonded to humic acids in a certain region. The results concerning the role of humic acids in the cycle of trace elements in Sava river biocycle are discussed.

  16. Accumulation of humic acid in DET/DGT gels

    Digital Repository Service at National Institute of Oceanography (India)

    Van der Veeken, P.L.R.; Chakraborty, P.; Van Leeuwen, H.P.

    effects of humic and fulvic acids on the DGT detection of metal species have been observed, the gel permeation properties of the actual humic and fulvic acid compounds themselves have not been analyzed thus far. Here we show with DET (Diffusive Equilibrium...

  17. Amino acids in the sedimentary humic and fulvic acids

    Digital Repository Service at National Institute of Oceanography (India)

    Sardessai, S.

    Humic and fulvic acids isolated from a few sediment samples from Arabian Sea and Bay of Bengal were analysed for total hydrolysable amino acids concentration and their composition. The amono acids content of fulvic acids was higher than in the humic...

  18. Coagulation of some humic acid solutions by Moringa oleifera Lam ...

    African Journals Online (AJOL)

    ABSTRACT. Experiments were carried out to study humic acid solutions and surface waters coagulation by Moringa oleifera Lam seeds aqueous extract. High amounts of such extract (up to. 10 g/L) were required to clarify humic acid solutions whereas 0.5 g/L were used to remove 90% of initial turbidity of a surface water.

  19. Phosphorus and humic acid application alleviate salinity stress of ...

    African Journals Online (AJOL)

    Humic acid is a commercial product that contains many elements which improve the soil fertility and increase the availability of nutrient elements. It consequently affects plant growth and yield and ameliorates the deleterious effects of salt stress. The objective of the study was to determine the effect of humic acids and ...

  20. DEVELOPMENT OF HUMICS-BASED DETOXICANTS OF COMPLEX EFFECT

    Directory of Open Access Journals (Sweden)

    S.P Li.

    2012-06-01

    Full Text Available This research demonstrated development and properties of detoxicants of integrated effect based on humic derivatives. Set of samples of humic-based derivatives including carbonylated, hydrophobizated, oxygenated, cryodestructed and biosolubilized have been synthesized. It has been demonstrated that all the produced detoxicants possessed plant growth promoting activity and detoxifying potential in relation to heavy metals.

  1. Interaction of metals with humic acid isolated from oxidized coal

    Energy Technology Data Exchange (ETDEWEB)

    Erdogan, S.; Baysal, A.; Akba, O.; Hamamci, C. [Dicle University, Diyarbakir (Turkey)

    2007-07-01

    The sorption behaviour of divalent cations M{sup 2+} (Cu, Pb and Zn) and trivalent cations M{sup 2+} (Fe, Al) with humic acid isolated from oxidized coal (Hazro, SE Anatolia,Turkey) was followed in aqueous solution. Coal humic acid and metal ion interaction was investigated with special emphasis on the effects of pH, metal ion concentration and humic acid concentration. It has been found that the interaction of humic acid with metal ions in solution increases with pH, decreases with metal ion concentration and increases with humic acid concentration. The differences in sorption ability of particular metal ions on oxidized coal-derived humic acid are Fe> Pb> Cu> Al> Zn and Fe> Pb> Al> Cu> Zn at pH 2.5 and 3.5, respectively, while they are Fe=Pb=Cu=Al> Zn at both pH 4.5 and 5.5. The interaction of some trivalent (Fe, Al) and divalent (Cu, Pb, Zn) metal ions with humic acid prepared from coal was also studied using FTIR spectroscopy. This has proven helpful with respect to metal binding to understand better the potential sites of binding within the humic acid. Infrared spectroscopy showed the participation of COOH and OH groups in binding to the metal ions.

  2. Characterization of metal/humic acid systems by Capillary Electrophoresis

    NARCIS (Netherlands)

    Staden JJ van; Hoop MAGT van den; Cleven R; LAC

    2000-01-01

    Metal-humic acid systems have been characterised applying Capillary Electrophoresis (CE). Appropriate experimental conditions with respect to carrier electrolyte, pH range, salt concentration, humic acid concentration and the applied potential, have been optimised. The influence of multivalent metal

  3. Sorption of curium by silica colloids: Effect of humic acid

    Energy Technology Data Exchange (ETDEWEB)

    Kar, Aishwarya Soumitra; Kumar, Sumit [Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Tomar, B.S., E-mail: bstomar@barc.gov.in [Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Manchanda, V.K. [Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

    2011-02-28

    Sorption of curium by silica colloids has been studied as a function of pH and ionic strength using {sup 244}Cm as a tracer. The sorption was found to increase with increasing pH and reach a saturation value of {approx}95% at pH beyond 5.3. The effect of humic acid on the sorption of {sup 244}Cm onto silica was studied by changing the order of addition of the metal ion and humic acid. In general, in the presence of humic acid (2 mg/L), the sorption increased at lower pH (<5) while it decreased in the pH range 6.5-8 and above pH 8, the sorption was found to increase again. As curium forms strong complex with humic acid, its presence results in the enhancement of curium sorption at lower pH. At higher pH the humic acid present in the solution competes with the surface sites for curium thus decreasing the sorption. The decrease in the Cm sorption in presence of humic acid was found to be less when humic acid was added after the addition of curium. Linear additive model qualitatively reproduced the profile of the Cm(III) sorption by silica in presence of humic acid at least in the lower pH region, however it failed to yield quantitative agreement with the experimental results. The results of the present study evidenced the incorporation of Cm into the silica matrix.

  4. Phosphorus and humic acid application alleviate salinity stress of ...

    African Journals Online (AJOL)

    ONOS

    2010-09-06

    Sep 6, 2010 ... Humic acids may stimulate shoot and root growth, and improve resistance to environmental stress in plant, but the physiological mechanism has not been well established (Delfine et al., 2005). Türkmen et al. (2005) suggested that humic acid may promote much growth of pepper seedlings in salty condition.

  5. Accessibility of humic-associated Fe to a microbial siderophore: implications for bioavailability.

    Science.gov (United States)

    Kuhn, Keshia M; Maurice, Patricia A; Neubauer, Elisabeth; Hofmann, Thilo; von der Kammer, Frank

    2014-01-21

    Microorganisms in aerobic, circum-neutral environments are challenged to acquire sufficient nutrient Fe due to low solubilities of Fe oxides. To overcome this challenge, many aerobic microbes produce low molecular weight (MW) organic ligands, or siderophores, with extremely high Fe-binding affinities. This research expands the existing understanding of siderophore-mediated Fe acquisition from minerals by examining the effects of the siderophore desferrioxamine B (DFOB) on Fe removal from aquatic humic substances (XAD-8-isolated) and other organic matter (OM) isolates (reverse osmosis, RO; and "transphilic", XAD-4) from several rivers including the Suwannee River (GA, USA). Analysis of samples by asymmetrical flow field-flow fractionation (AsFlFFF) with in-line ICP-MS and UV-vis detectors showed that Fe was naturally abundant and primarily associated with intermediate to high MW OM. An excess of DFOB (relative to naturally present Fe) removed ∼ 75% of Fe and shifted the OM MW distribution to lower MWs, perhaps due to removal of "bridging" Fe, although additional mechanistic study of MW shifts is needed. Removal of other OM-associated metals (e.g., Al, Cu, Zn) by DFOB was minimal for all but a few samples. Fe bound to humic substances and other more "transphilic" organic components therefore should be considered readily bioavailable to aerobic, siderophore-producing microorganisms.

  6. [Influence of straw manuring on the qualitative properties of the organic soil substances of a Lehm-Braunschwarzerde (author's transl)].

    Science.gov (United States)

    Heisig, W; Müller, G; Lingner, D

    1980-01-01

    It is reported on the influence of a long-term field trial with straw manuring at different terms and different nitrogen fertilization steps on the qualitative properties of the organic soil substance. Straw manuring in autumn increased the carbon content in the soil. Increasing amounts of nitrogen intensified this effect. Straw manuring in spring only with simultaneously applied quantities of 100 and 200 kg N/ha, respectively, brought about an increased content of organic substances in soil. With straw manuring in autumn, fractionation of the organic substance in soil showed a smaller amount of humic acids. Increasing nitrogen addition reduced this amount still more than in the plots with straw manuring in spring. The quota of fulvic acids increased. Therefore, the higher content of organic substances, obtained with straw manuring in autumn, is based on an increase of the pre-stages of humic acids and non-humic matter.

  7. MODELING LANTHANIDE BINDING SITES ON HUMIC ACID

    OpenAIRE

    Pourret, Olivier; Martinez, Raul,

    2009-01-01

    International audience; Lanthanide (Ln) binding to humic acid (HA) has been investigated by combining ultrafiltration and ICP-MS techniques. A Langmuir sorption isotherm metal complexation model was used in conjunction with a linear programming method (LPM) to fit experimental data representing a wide range of experimental conditions both in HA/Ln ratio (varying between 5 and 20) and in pH range (from 2 to 10) with a ionic strength of 10-3 mol L-1. The LPM approach, not requiring prior knowle...

  8. Rare earth elements complexation with humic acid

    OpenAIRE

    Pourret, Olivier; Davranche, Mélanie; Gruau, Gérard; Dia, Aline

    2007-01-01

    The binding of rare earth elements (REE) to humic acid (HA) was studied by combining ultrafiltration and Inductively Coupled Plasma Mass Spectrometry techniques. REE­HA complexation experiments were performed at various pH conditions (ranging from 2 to 10.5) using a standard batch equilibration method. Results show that the amount of REE bound to HA strongly increases with increasing pH. Moreover, a Middle-REE (MREE) downward concavity is evidenced by REE distribution patterns at acidic pH. M...

  9. Lability of copper bound to humic acid

    OpenAIRE

    Mao, Lingchen; Young, Scott D.; Bailey, Liz

    2015-01-01

    Geochemical speciation models generally include the assumption that all metal bound to humic acid and fulvic acid (HA, FA) is labile. However, in the current study, we determined the presence of a soluble ‘non-labile’ Cu fraction bound to HA extracted from grassland and peat soils. This was quantified by determining isotopically-exchangeable Cu (E-value) and EDTA-extraction of HA-bound Cu, separated by size-exclusion chromatography (SEC) and assayed by coupled ICP-MS. Evidence of time-depend...

  10. Removal of humic acid from peat soils by using AlCl3 prior to DNA extraction

    Science.gov (United States)

    Mustafa, Irfan; Hadiatullah, Sustiyah

    2017-05-01

    The amplification of environmental DNA is one of the main steps in microbial diversity profiling of environmental samples. To represent the microbial community in the soil, DNA extraction is initially needed. The major inhibitor in the soil is a humic acid which greatly inhibits the ability of enzymes to amplify DNA. The protocol provided with the commercial kit was not able to resolve the problem. We, therefore, introduced a modification for soil sample treatment with AlCl3 as a flocculating agent that is capable of removing the humic substance contained in peat soil. This technique was superior to the original instruction for extracting DNA with the FastDNA® Spin Kit for Soil (MP Bio, USA).

  11. Successions and diversity of humic-reducing microorganisms and their association with physical-chemical parameters during composting.

    Science.gov (United States)

    Xi, Beidou; Zhao, Xinyu; He, Xiaosong; Huang, Caihong; Tan, Wenbing; Gao, Rutai; Zhang, Hui; Li, Dan

    2016-11-01

    Humic-reducing microorganisms (HRMs) could utilize humic substances (HS) as terminal electron mediator to promote the biodegradation of recalcitrant pollutants. However, the dynamics of HRMs during composting has not been explored. Here, high throughput sequencing technology was applied to investigate the patterns of HRMs during three composting systems. A total of 30 main genera of HRMs were identified in three composts, with Proteobacteria being the largest phylum. HRMs were detected with increased diversity and abundance and distinct patterns during composting, which were significantly associated with dissolved organic carbon, dissolved organic nitrogen and germination index. Regulating key physical-chemical parameters is a process control of HRMs community composition, thus promoting the redox capability of the compost. The redox capability of HRMs were strengthened during composting, suggesting that HRMs of the compost may play an important role on pollutant degradation of the compost or when they are applied to the contaminated soils. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Impact of Humic Acid on Yield and Quality of Sugar Beet (Beta vulgaris L. Grown on Calcareous Soil

    Directory of Open Access Journals (Sweden)

    Ghorbanali RASSAM

    2015-09-01

    Full Text Available A field experiment was performed to determine the effects of using humic acid with irrigation on quantitative and qualitative yield traits of sugar beet grown on calcareous soils in Esfaraen, located in the North-East of Iran. Treatments consisted of three levels of humic acid concentration (zero or control, 2.5 and 5 L ha-1 and the number of applications (once 45 days after planting; twice, 45 and 75 days after planting; three times, respectively 45, 75 and 105 days after planting. The effect of the two experimental factors on sugar beet yield traits such as the content of sucrose, refined sugar, molasses forming substances, root yield and refined sugar yield were evaluated. The results proved the existence of a significant interaction between humic acid concentration and the number of applications on all parameters under study. The application of humic acid caused a significant increase of sucrose, refined sugar, root yield and refined sugar yield and a reduction in molasses forming substances content, compared to the control. The increased amount of sucrose and refined sugar content in all applications in concentration of 2.5 L ha-1 humic acid was more than with 5 L ha-1. Similarly, the content of molasses forming substances showed more reduction in 2.5 L ha-1 than in 5 L ha-1 treatment. However, the results revealed that the highest root yield and refined sugar yield, as the main qualitative and quantitative parameters of sugar beet yield, were achieved by three times application of 5 L ha-1 that had 24 and 37% increase compared to control.

  13. Precipitation of humic acid with divalent ions

    DEFF Research Database (Denmark)

    Andersen, Niels Peder Raj; Mikkelsen, Lene Haugaard; Keiding, Kristian

    2001-01-01

    The aim of this study is to investigate precipitation proper-ties of humic acid (HA). This is done by studying a commercial available humic acid salt (HA) from which a phase diagram is established by adding various amounts of BaCl2 to different concentrations of HA at pH 5.5. The phase diagram...... shows tree characteristic regions with markedly different precipitation courses: region I at HA concentration below 0.15g/l, region H at HA concentration between 0.15 and similar to2g/l and rgeion IV at HA concentration above 3.5g/l. Furthermore, a forth intermediate region M is observed between similar...... to2 and 3.5g/l. In order to understand these measurements and precipitation behaviour a phase diagram model is constructed using a simple thermodynamic approach. The result of this analysis shows that precipitation in region I and U can be explained by a simple equilibrium reaction between the HA...

  14. The stabilization of tannery sludge and the character of humic acid-like during low temperature pyrolysis.

    Science.gov (United States)

    Ma, Hongrui; Gao, Mao; Hua, Li; Chao, Hao; Xu, Jing

    2015-11-01

    Tannery sludge contained plenty of organic matter, and the organic substance stability had direct impact on its derived chars' utilization. In this paper, the stabilization of tannery sludge and the variation of humic acid-like (HAL) extracted by different methods were investigated in a magnetic stirring reactor under low temperature pyrolysis of 100-400 °C. Results showed that the aromatic structure of pyrolysis chars increased with the increase of temperature and time. The char contained highly aromatic structure and relatively small dissolved organic matters (DOM) at 300 °C. The similar behaviors appeared in two HAL series by different extraction methods. The N content, H/C value, and aliphatic structures of HAL decreased with the increase of pyrolysis temperature, while the C/N value and aromatic structures increased with the rise of pyrolysis temperature. The composition and functional groups of HAL were similar with the purchased humic acid (HA). The fluorescence spectra revealed that two main peaks were found at Ex/Em = 239/363-368 nm and 283/359-368 nm in each HAL series from raw and 100 °C pyrolysis tannery sludge, representing a protein-like matter. The new peak appeared at Ex/Em = 263-283/388 nm in each HAL series from 200 °C pyrolysis tannery sludge-represented humic acid-like matter. The fluorescence intensity increased strongly compared to the other two peak intensity. Therefore, the humification of organic matter was increased by pyrolyzing. Notably, the HAL from 200 °C pyrolysis tannery sludge contained simple molecular structure, and the polycondensation increased but with a relative lower humification degree compared to soil HAL and purchased HA. Therefore, the sludge needs further oxidation. The humic substance was negligible by direct extraction when the temperature was 300 and 400 °C.

  15. Effect of probiotics and humic acid on egg production and internal quality parameters of laying hens eggs

    Directory of Open Access Journals (Sweden)

    Henrieta Arpášová

    2016-10-01

    Full Text Available The aim of our experiment was to evaluate the influence of probiotic preparation based on lactobacillus, probiotic preparation based on enterococci or humic acid on egg production and selected internal egg quality parameters of laying hens hybrid Lohman Brown Lite. For housing hens (n ​​= 60 three storey enriched battery cage was used in which hens were divided in groups (n = 15. In the control group of hens complete feed mixtures without any additions were fed. In the first experimental group complete feed mixture was enriched with probiotic lactobacilli based preparation in a dose of 0.5 g.kg-1. In the second experimental group probiotic enterococci based preparation was added to the feed mixture at a dose of 0.5 g.kg-1. The third experimental group was enriched with 0.5% concentration of humic acid. All groups were fed ad libitum. Egg production and egg weight were recorded daily. Complete analysis of the table egg quality was used to evaluate quality parameters: yolk weight (g, yolk index, yolk colour (°HLR, albumen weight (g, Haugh Units (HU, albumen index. The results show that supplementation of feed mixture with both kind probiotics as well as humic acid increased egg production (P>0.05 (values of average intensity of laying in the order of the groups: 90.5; 91.9; 91.6 and 92.3 %. The addition of probiotics also positively influenced egg weight (P>0.05. The qualitative parameters of egg internal content were with probiotics or humic acids addition insignificantly influenced (P>0.05. Doses of supplements used in this study did not significant negatively influenced monitored egg quality parameters. Based on these findings and the beneficial effects of substances on the poultry health confirmed by other authors we recommend use of these substances as supplements to the feed mixtures for laying hens.

  16. Effects of Salicylic acid and Humic acid on Vegetative Indices of Periwinkle (Catharanthus roseusL.

    Directory of Open Access Journals (Sweden)

    E. Chamani

    2016-07-01

    Full Text Available Introduction: Vinca flower (Catharanthus roseus L. is one of the most important medicinal plants of Apocynaceae (31, 27. Tropical plant native to a height of 30 to 35 centimeters (9 and a perennial shrub which is grown in cold areas for one year (27.One of the plants in the world today as a medicinal plant used the periwinkle plant. Among the 130 indole – terpenoids alkaloids which have been identified in the plant periwinkle vinca alkaloids vincristine and vinblastin are the most important component is used to treat a variety of cancers. Including therapies that are used for a variety of cancer, chemotherapy to help Vinca alkaloids collection (including vincristine and…. Vinblastin as effective member of this category, due to the low percentage of venom and effects at very low doses, is widely used today. These materials are generally formed as inhibitors of mitotic spindle in dividing cells have been identified. Vinblastin with these structural changes in connection kinotokor - microtubules and centrosomes in a dividing cell, the mitotic spindle stop (45.Salicylic acid belongs to a group of phenolic compounds found in plants, and today is widely regarded as a hormone-like substance. These classes of compounds act as growth regulators. Humic substances are natural organic compounds that contain 50 to 90% of organic matter, peat, charcoal, rotten food and non-living organic materials are aquatic and terrestrial ecosystems (2. Materials and Methods: In this experiment, vinca F2 seeds in the mixed 4: 1 perlite and peat moss to the planting trays were sown. The seedlings at the 6-leaf stage were transfered to the main pot (pot height 30 and 25 cm diameter The pots bed soil mix consisting of 2 parts soil to one part sand and one part peat moss (v / v were used and after the establishment of seedlings in pots every two weeks with. Salicylic acid and humic acid concentrations 0 (control, 10, 100, 500 and 1000 mg were treated as a foliar spray

  17. Clean coal technologies---An international seminar: Seminar evaluation and identification of potential CCT markets

    Energy Technology Data Exchange (ETDEWEB)

    Guziel, K.A.; Poch, L.A.; Gillette, J.L.; Buehring, W.A.

    1991-07-01

    The need for environmentally responsible electricity generation is a worldwide concern. Because coal is available throughout the world at a reasonable cost, current research is focusing on technologies that use coal with minimal environmental effects. The United States government is supporting research on clean coal technologies (CCTs) to be used for new capacity additions and for retrofits to existing capacity. To promote the worldwide adoption of US CCTs, the US Department of Energy, the US Agency for International Development, and the US Trade and Development Program sponsored a two-week seminar titled Clean Coal Technologies -- An International Seminar. Nineteen participants from seven countries were invited to this seminar, which was held at Argonne National Laboratory in June 1991. During the seminar, 11 US CCT vendors made presentations on their state-of-the-art and commercially available technologies. The presentations included technical, environmental, operational, and economic characteristics of CCTs. Information on financing and evaluating CCTs also was presented, and participants visited two CCT operating sites. The closing evaluation indicated that the seminar was a worthwhile experience for all participants and that it should be repeated. The participants said CCT could play a role in their existing and future electric capacity, but they agreed that more CCT demonstration projects were needed to confirm the reliability and performance of the technologies.

  18. Programme of Seminars January to March 2004

    CERN Multimedia

    2004-01-01

    If you wish to participate in one of the following courses, please discuss with your supervisor and apply electronically directly from the course description pages that can be found on the Web at: http://www.cern.ch/Training/ or fill in an "application for training" form available from your Divisional Secretariat or from your DTO (Divisional Training Officer). Applications will be accepted in the order of their receipt. MANAGEMENT & COMMUNICATION Nathalie Dumeaux tel. 78144 management.communication@cern.ch Situation : 20.01.2004 DatesDaysPlaces Available** Bilingual seminars Communication Techniques-1/Techniques de communication-1 16, 17, 18 March 3 non Project Management/Gestion de projet 17, 18, 19 March 3 oui Seminars in English Communicating effectively 22, 23 January & 19, 20 February 4 yes Performance Appraisal MAPS 4, 5, 6 February 3 yes Performance Appraisal -MAPS 11, 12, 13 February 3 yes Séminaires en Français Formation à l'entreti...

  19. Micro-organization of humic acids in aqueous solutions

    Science.gov (United States)

    Klučáková, Martina; Věžníková, Kateřina

    2017-09-01

    The methods of dynamic light scattering and micro-rheology were used to investigate the molecular organization of humic acids in solutions. The obtained results were supplemented by ultraviolet/visible spectrometry and measurement of the zeta potential. Particle tracking micro-rheology was used for the first time as a novel method in humic research. Solutions of humic acids were prepared in three different mediums: NaOH, NaCl, and NaOH neutralized by HCl after dissolution of the humic sample. The molecular organization of humic acids was studied over a wide concentration range (0.01-10 g dm-3). Two breaks were detected in the obtained concentration dependencies. The rearrangements were observed at concentrations around 0.02 g dm-3 and 1 g dm-3. Changes in the measured values observed at around 0.02 g dm-3 were less noticeable and were related to the formation of particles between 100 and 1000 nm in size and the strong bimodal character of humic systems diluted by NaCl. The ;switch-over point; at around 1 g dm-3 indicated changes in the secondary structure of humic acids connected with the increase in colloidal stability (decrease of zeta potential), the decrease in polydispersity, and minimal values of viscosity.

  20. Seminar: Music Therapy in Dementia Care

    DEFF Research Database (Denmark)

    Ridder, Hanne Mette Ochsner

    2009-01-01

    This seminar presents music therapy in person centered dementia care. In the first part focus is on research and documentation. How can short term music therapy document changes in symptoms of depression? Is Dementia Care Mapping a valid assessment tool for documenting group music therapy......? In the next part focus is on clinical music therapy – in group work as well as in individual work – and how the music therapist works in the interdisciplinary field....

  1. Computational Mass Spectrometry (Dagstuhl Seminar 13491)

    OpenAIRE

    Aebersbold, Ruedi; Kohlbacher, Oliver; Vitek, Olga

    2014-01-01

    The last decade has brought tremendous technological advances in mass spectrometry, which in turn have enabled new applications of mass spectrometry in the life sciences. Proteomics, metabolomics, lipidomics, glycomics and related fields have gotten a massive boost, which also resulted in vastly increased amount of data produced and increased complexity of these data sets. An efficient and accurate analysis of these data sets has become the key bottleneck in the field. The seminar 'Com...

  2. Unleashing Operational Process Mining (Dagstuhl Seminar 13481)

    OpenAIRE

    Accorsi, Rafael; Damiani, Ernesto; van der Aalst, Wil

    2014-01-01

    This report documents the program and the outcomes of Dagstuhl Seminar 13481 "Unleashing Operational Process Mining". Process mining is a young research discipline connecting computational intelligence and data mining on the one hand and process modeling and analysis on the other hand. The goal of process mining is to discover, monitor, diagnose and improve real processes by extracting knowledge from event logs readily available in today's information systems. Process mining bridges the gap b...

  3. High temperature electronics and instrumentation seminar proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Veneruso, A.F.; Arnold, C.; Simpson, R.S. (eds.)

    1980-05-01

    This seminar was tailored to address the needs of the borehole logging industry and to stimulate the development and application of this technology, for logging geothermal, hot oil and gas, and steam injection wells. The technical sessions covered the following topics: hybrid circuits, electronic devices, transducers, cables and connectors, materials, mechanical tools and thermal protection. Thirty-eight papers are included. Separate entries were prepared for each one. (MHR)

  4. 1990 fuel cell seminar: Program and abstracts

    Energy Technology Data Exchange (ETDEWEB)

    1990-12-31

    This volume contains author prepared short resumes of the presentations at the 1990 Fuel Cell Seminar held November 25-28, 1990 in Phoenix, Arizona. Contained herein are 134 short descriptions organized into topic areas entitled An Environmental Overview, Transportation Applications, Technology Advancements for Molten Carbonate Fuel Cells, Technology Advancements for Solid Fuel Cells, Component Technologies and Systems Analysis, Stationary Power Applications, Marine and Space Applications, Technology Advancements for Acid Type Fuel Cells, and Technology Advancement for Solid Oxide Fuel Cells.

  5. Seminar at the University of Texas

    CERN Document Server

    Rosenthal, Haskell

    1988-01-01

    The articles in this volume are based on talks given in a seminar at Austin during 1986-87. They range from those dealing with fresh research and discoveries to exposition and new proofs of older results. The main topics and themes include geometric and analytic properties of infinite-dimensional Banach spaces and their convex subsets as well as some aspects of Banach spaces associated with harmonic analysis and Banach algebras.

  6. Seminar on waste treatment and disposal

    Energy Technology Data Exchange (ETDEWEB)

    Sneve, Malgorzata Karpow; Snihs, Jan Olof

    1999-07-01

    Leading abstract. A seminar on radioactive waste treatment and disposal was held 9 - 14 November 1998 in Oskarshamn, Sweden. The objective of the seminar was to exchange information on national and international procedures, practices and requirements for waste management. This information exchange was intended to promote the development of a suitable strategy for management of radioactive waste in Northwest Russia to be used as background for future co-operation in the region. The seminar focused on (1) overviews of international co-operation in the waste management field and national systems for waste management, (2) experiences from treatment of low- and intermediate-level radioactive waste, (3) the process of determining the options for final disposal of radioactive waste, (4) experiences from performance assessments and safety analysis for repositories intended for low- and intermediate level radioactive waste, (5) safety of storage and disposal of high-level waste. The seminar was jointly organised and sponsored by the Swedish Radiation Protection Institute (SSI), the Norwegian Radiation Protection Authority (NRPA), the Nordic Nuclear Safety Research (NKS) and the European Commission. A Russian version of the report is available. In brief, the main conclusions are: (1) It is the prerogative of the Russian federal Government to devise and implement a waste management strategy without having to pay attention to the recommendations of the meeting, (2) Some participants consider that many points have already been covered in existing governmental documents, (3) Norway and Sweden would like to see a strategic plan in order to identify how and where to co-operate best, (4) There is a rigorous structure of laws in place, based on over-arching environmental laws, (5) Decommissioning of submarines is a long and complicated task, (6) There are funds and a desire for continued Norway/Sweden/Russia co-operation, (7) Good co-operation is already taking place.

  7. Application of humic compounds for remediation of soils contaminated with heavy metals: the benefits and risks

    Science.gov (United States)

    Motuzova, Galina; Barsova, Natalia; Stepanov, Andrey; Kiseleva, Violetta; Kolchanova, Ksenia; Starkova, Irina; Karpukhin, Mikhail

    2015-04-01

    Applicability of humic compound (HC) "Extra" (potassium humate produced from coal) was studied to remediate soils contaminated with copper in model experiments. Field experiments were carried out in 10-litter plastic containers. The upper layer was prepared as a mixture of loam (pH=5.3), sand (pH=7.4) and peat(pH=5.5). It was underlain consequently by loam and gravel. To study water migration we installed lysimeters. The experiment was conducted in 3 variants: 1) control, 2) control+Cu, 3) control+Cu+HC. Copper was applied in the form of dry powder (CuSO4*5H2O) over the upper layer of the soil column in a concentration of copper equaling to 1000 mg/kg. Total concentration of copper was determined by ICP AAS, its free ions was measured with the help of ion-selective electrode. Humic compound was sprayed on the surface in liquid form. The vessels stayed outdoors from July to October 2014 with additional watering in dry periods. Analysis of lysimetric waters obtained from this model field experiment revealed significant impact of pH. Application of the humic compound produces almost 5 times higher content of soluble organic substances than in the variant without it, and in the first portions of lysimetric waters the difference is 20-fold. Generation of extra organic content in soluble form was accompanied by the 2-6 times increase of the water soluble copper yield. However the content of the free copper ions in lysimetric waters in case of addition of the potassium humate was negligible, because almost all copper was bounded with water-soluble organic substances. The copper content in water extract from the top layer of soil in the variant with HC was about 1 mg/l, that was 2 times higher than without HC. The content of water-soluble organic carbon in HC variant was 100 mg/L, and without HC was 10 times lower (10 mg/l). The water extract from soils enriched in HC was passed through a column filled with weakly basic anion exchange resin DEAE (Cl-form), the eluate was

  8. Golden Years or Financial Fears? Decision Making After Retirement Seminars

    OpenAIRE

    Allen, Steven G.; Clark, Robert L.; Jennifer Maki; Melinda Sandler Morrill

    2013-01-01

    Many organizations provide retirement planning seminars to their employees as a benefit to help them make better informed retirement decisions. This study examines the participants in 85 seminars conducted by five companies in 2008 and 2009 to determine how much learning takes place and whether employees adjust retirement plans. Using surveys conducted before and after the seminars, we find that financial literacy and knowledge of retirement program parameters are significantly higher after t...

  9. Report of the European Energy Law seminar 2011; Verslag European Energy Law seminar 2011

    Energy Technology Data Exchange (ETDEWEB)

    Holwerda, J.M.; Mueller, H.K. [Groningen Centre of Energy Law, Rijksuniversiteit Groningen RUG, Groningen (Netherlands); Mutsaers, A. [De Brauw Blackstone Westbroek, Amsterdam (Netherlands)

    2011-10-15

    The 24th European Energy Law Seminar was held in Noordwijk aan Zee, Netherlands, 11-12 April 2011. The first day attention was paid to the liberalization of the energy markets, the climate and energy. The second day was dedicated to energy security, the upstream sector and development of energy infrastructure. [Dutch] Op 11 en 12 april 2011 vond te Noordwijk aan Zee wederom het jaarlijkse - 24ste - European Energy Law Seminar plaats. De eerste dag stond in het teken van de liberalisering van de energiemarkten en klimaat- en energie, terwijl de tweede dag gewijd was aan energievoorzieningszekerheid, de upstream sector en ontwikkeling van de energie-infrastructuur.

  10. Spectroscopic and conformational properties of size-fractions acid separated from a lignite humic

    Energy Technology Data Exchange (ETDEWEB)

    Conte, P.; Spaccini, R.; Smejkalova, D.; Nebbioso, A.; Piccolo, A. [University of Naples Federico 2, Portici (Italy)

    2007-10-15

    A lignite humic acid (HA) was fractionated by preparative high performance size-exclusion chromatography (HPSEC) in seven different size-fractions. The size-fractions were characterized by cross polarization (CP) magic angle spinning (MAS) {sup 13}C NMR spectroscopy and a further analytical HPSEC elution under UV and fluorescence detection. The alkyl hydrophobic components mainly distributed in the largest molecular-size-fraction, whereas the amount of oxidized carbons increased with decreasing size of fractions. Cross polarization time (T{sub CH}) and proton spin-lattice relaxation time in the rotating frame (T{sub 1p}(H)) were measured from variable contact time (VCT) experiments. The bulk HA was characterized by the shortest T{sub CH} values and the longest T{sub 1p}(H) values which suggested, respectively, one, an aggregation of components in a large conformation that favored a fast H-C cross polarization, and, two, consequent steric hindrances that prevented fast local molecular motions and decreased proton relaxation rates. Conversely, the separated size-fractions showed longer T{sub CH} values and shorter T{sub 1p}(H) values than the bulk HA, thereby indicating that they were constituted by a larger number of mobile molecular conformations. The UV and fluorescence absorptions were both low in the large size-fractions that mainly contained alkyl carbons, whereas they increased in the olephinic- and aromatic-rich fractions with intermediate molecular-size, and decreased again in the smaller fractions which were predominantly composed by oxidized carbons. These results support the supramolecular structure of humic Substances and indicate that the observed variation in conformational distribution in humic association may be used to explain environmental processes with additional precision.

  11. Acid-base properties of humic and fulvic acids formed during composting.

    Science.gov (United States)

    Plaza, César; Senesi, Nicola; Polo, Alfredo; Brunetti, Gennaro

    2005-09-15

    The soil acid-base buffering capacity and the biological availability, mobilization, and transport of macro- and micronutrients, toxic metal ions, and xenobiotic organic cations in soil are strongly influenced by the acid-base properties of humic substances, of which humic and fulvic acids are the major fractions. For these reasons, the proton binding behavior of the humic acid-like (HA) and fulvic acid-like (FA) fractions contained in a compost are believed to be instrumental in its successful performance in soil. In this work, the acid-base properties of the HAs and FAs isolated from a mixture of the sludge residue obtained from olive oil mill wastewater (OMW) evaporated in an open-air pond and tree cuttings (TC) at different stages of composting were investigated by a current potentiometric titration method and the nonideal competitive adsorption (NICA)-Donnan model. The NICA-Donnan model provided an excellent description of the acid-base titration data, and pointed out substantial differences in site density and proton-binding affinity between the HAs and FAs examined. With respect to FAs, HAs were characterized by a smaller content of carboxylic- and phenolic-type groups and their larger affinities for proton binding. Further, HAs featured a greater heterogeneity in carboxylic-type groups than FAs. The composting process increased the content and decreased the proton affinity of carboxylic- and phenolic-type groups of HAs and FAs, and increased the heterogeneity of phenolic-type groups of HAs. As a whole, these effects indicated that the composting process could produce HA and FA fractions with greater cation binding capacities. These results suggest that composting of organic materials improves their agronomic and environmental value by increasing their potential to retain and exchange macro- and micronutrients, and to reduce the bioavailability of organic and inorganic pollutants.

  12. Comprehensive comparison of the chemical and structural characterization of landfill leachate and leonardite humic fractions.

    Science.gov (United States)

    Tahiri, Abdelghani; Richel, Aurore; Destain, Jacqueline; Druart, Philippe; Thonart, Philippe; Ongena, Marc

    2016-03-01

    Humic substances (HS) are complex and heterogeneous mixtures of organic compounds that occur everywhere in the environment. They represent most of the dissolved organic matter in soils, sediments (fossil), water, and landfills. The exact structure of HS macromolecules has not yet been determined because of their complexity and heterogeneity. Various descriptions of HS are used depending on specific environments of origin and research interests. In order to improve the understanding of the structure of HS extracted from landfill leachate (LHS) and commercial HS from leonardite (HHS), this study sought to compare the composition and characterization of the structure of LHS and HHS using elemental composition, chromatographic (high-performance liquid chromatography (HPLC)), and spectroscopic techniques (UV-vis, FTIR, NMR, and MALDI-TOF). The results showed that LHS molecules have a lower molecular weight and less aromatic structure than HHS molecules. The characteristics of functional groups of both LHS and HHS, however, were basically similar, but there was some differences in absorbance intensity. There were also less aliphatic and acidic functional groups and more aromatic and polyphenolic compounds in the humic acid (HA) fraction than in the fulvic acid (FA) and other molecules (OM) fractions of both origins. The differences between LHS and HHS might be due to the time course of humification. Combining the results obtained from these analytical techniques cold improve our understanding of the structure of HS of different origins and thus enhance their potential use.

  13. Effect of long-term fertilization on humic redox mediators in multiple microbial redox reactions.

    Science.gov (United States)

    Guo, Peng; Zhang, Chunfang; Wang, Yi; Yu, Xinwei; Zhang, Zhichao; Zhang, Dongdong

    2018-03-01

    This study investigated the effects of different long-term fertilizations on humic substances (HSs), humic acids (HAs) and humins, functioning as redox mediators for various microbial redox biotransformations, including 2,2',4,4',5,5'- hexachlorobiphenyl (PCB 153 ) dechlorination, dissimilatory iron reduction, and nitrate reduction, and their electron-mediating natures. The redox activity of HSs for various microbial redox metabolisms was substantially enhanced by long-term application of organic fertilizer (pig manure). As a redox mediator, only humin extracted from soils with organic fertilizer amendment (OF-HM) maintained microbial PCB 153 dechlorination activity (1.03 μM PCB 153 removal), and corresponding HA (OF-HA) most effectively enhanced iron reduction and nitrate reduction by Shewanella putrefaciens. Electrochemical analysis confirmed the enhancement of their electron transfer capacity and redox properties. Fourier transform infrared analysis showed that C=C and C=O bonds, and carboxylic or phenolic groups in HSs might be the redox functional groups affected by fertilization. This research enhances our understanding of the influence of anthropogenic fertility on the biogeochemical cycling of elements and in situ remediation ability in agroecosystems through microorganisms' metabolisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Gladiolus development in response to bulb treatment with different concentrations of humic acids

    Directory of Open Access Journals (Sweden)

    Marihus Altoé Baldotto

    2013-02-01

    Full Text Available Gladiolus is an ornamental species produced for cut flowers and propagated by corms. The early flowering and increase in the number of flower buds, besides the production of commercial corms are constant challenges to be addressed in the crop improvement. Commercial production of ornamentals is technologically accelerated by means of growth regulators. Among them, the auxins stand out for their key role in the adventitious rooting and cell elongation. Alternatively, the humic substances present in the organic matter also have biostimulating effect, which is very similar to the auxinic effect. Therefore, this work aimed to study the growth and development of gladiolus in response to application of different concentrations of humic acids (HA isolated from vermicompost. Corms were soaked for 24 hours in solutions containing 0, 10, 20, 30 and 40 mmol L-1 of C from HA. The corms were planted in 10-dm³ plastic bags filled with substrate and kept in a greenhouse. Growth of shoots and roots was evaluated. The results showed that the use of HA accelerates growth, and anticipates and increases flowering of Gladiolus.

  15. Label Distribution in Tissues of Wheat Seedlings Cultivated with Tritium-Labeled Leonardite Humic Acid

    Science.gov (United States)

    Kulikova, Natalia A.; Abroskin, Dmitry P.; Badun, Gennady A.; Chernysheva, Maria G.; Korobkov, Viktor I.; Beer, Anton S.; Tsvetkova, Eugenia A.; Senik, Svetlana V.; Klein, Olga I.; Perminova, Irina V.

    2016-06-01

    Humic substances (HS) play important roles in the biotic-abiotic interactions of the root plant and soil contributing to plant adaptation to external environments. However, their mode of action on plants remains largely unknown. In this study the HS distribution in tissues of wheat seedlings was examined using tritium-labeled humic acid (HA) derived from leonardite (a variety of lignites) and microautoradiography (MAR). Preferential accumulation of labeled products from tritiated HA was found in the roots as compared to the shoots, and endodermis was shown to be the major control point for radial transport of label into vascular system of plant. Tritium was also found in the stele and xylem tissues indicating that labeled products from tritiated HA could be transported to shoot tissues via the transpiration stream. Treatment with HA lead to an increase in the content of polar lipids of photosynthetic membranes. The observed accumulation of labeled HA products in root endodermis and positive impact on lipid synthesis are consistent with prior reported observations on physiological effects of HS on plants such as enhanced growth and development of lateral roots and improvement/repairs of the photosynthetic status of plants under stress conditions.

  16. Mechanism of the toxicity induced by natural humic acid on human vascular endothelial cells.

    Science.gov (United States)

    Kihara, Yusuke; Yustiawati; Tanaka, Masato; Gumiri, Sulmin; Ardianor; Hosokawa, Toshiyuki; Tanaka, Shunitz; Saito, Takeshi; Kurasaki, Masaaki

    2014-08-01

    Humic acid (HA), a group of high-molecular weight organic compounds characterized by an ability to bind heavy metals, is normally found in natural water. Although the impairment of vascular endothelial cells in the presence of humic substances has been reported to be involved in some diseases, the mechanisms responsible for this involvement remain unclear. In this study, we examined the cytotoxicity of HA obtained from peatland in Central Kalimantan, Indonesia, to human vascular endothelial cells, as well as the mechanisms behind these effects. It was found that 50 mg/L HA showed cytotoxicity, which we considered to be mediated by apoptosis through the mitochondrial pathway because of an increase in the expression of caspases 6 and 9 in response to HA administration. In addition, this cytotoxicity was enhanced when cells in this experimental system were exposed to oxidative stress, while it was decreased by the addition of vitamin C. Thus, we conclude that the apoptosis induced by HA depends upon oxidative stress. Furthermore, an iron chelator, DFO, showed a tendency to decrease HA-induced cytotoxicity, suggesting that iron may potentially mediate HA-induced oxidative stress. In conclusion, long-term consumption of HA-rich water obtained from our study area may cause damage to endothelial cells and subsequent chronic health problems. Copyright © 2012 Wiley Periodicals, Inc., a Wiley company.

  17. Measurement of humic and fulvic acid concentrations and dissolution properties by a rapid batch procedure

    Energy Technology Data Exchange (ETDEWEB)

    Van Zomeren, A.; Comans, R.N.J. [ECN Biomass, Coal and Environmental Research, Petten (Netherlands)

    2007-08-29

    Although humic substances (HS) strongly facilitate the transport of metals and hydrophobic organic contaminants in environmental systems, their measurement is hampered by the time-consuming nature of currently available methods for their isolation and purification. We present and apply a new rapid batch method to measure humic (HA) and fulvic (FA) acid concentrations and dissolution properties in both solid and aqueous samples. The method is compared with the conventional procedures and is shown to substantially facilitate HS concentration measurements, particularly for applications such as geochemical modeling where HS purification is not required. The new method can be performed within 1.5-4 h per sample and multiple samples can be processed simultaneously, while the conventional procedures typically require approximately 40 h for a single sample. In addition, specific dissolution properties of HS are identified and are consistent with recent views on the molecular structure of HS that emphasize molecular interactions of smaller entities over distinct macromolecular components. Because the principles of the new method are essentially the same as those of generally accepted conventional procedures, the identified HA and FA properties are of general importance for the interpretation of the environmental occurrence and behavior of HS.

  18. Kinetics of rapid covalent bond formation of aniline with humic acid: ESR investigations with nitroxide spin labels

    Science.gov (United States)

    Glinka, Kevin; Matthies, Michael; Theiling, Marius; Hideg, Kalman; Steinhoff, Heinz-Jürgen

    2016-04-01

    Sulfonamide antibiotics used in livestock farming are distributed to farmland by application of slurry as fertilizer. Previous work suggests rapid covalent binding of the aniline moiety to humic acids found in soil. In the current work, kinetics of this binding were measured in X-band EPR spectroscopy by incubating Leonardite humic acid (LHA) with a paramagnetic aniline spin label (anilino-NO (2,5,5-Trimethyl-2-(3-aminophenyl)pyrrolidin-1-oxyl)). Binding was detected by a pronounced broadening of the spectral lines after incubation of LHA with anilino-NO. The time evolution of the amplitude of this feature was used for determining the reaction kinetics. Single- and double-exponential models were fitted to the data obtained for modelling one or two first-order reactions. Reaction rates of 0.16 min-1 and 0.012 min-1, were found respectively. Addition of laccase peroxidase did not change the kinetics but significantly enhanced the reacting fraction of anilino-NO. This EPR-based method provides a technically simple and effective method for following rapid binding processes of a xenobiotic substance to humic acids.

  19. Aggregation and disaggregation of ZnO nanoparticles: influence of pH and adsorption of Suwannee River humic acid.

    Science.gov (United States)

    Mohd Omar, Fatehah; Abdul Aziz, Hamidi; Stoll, Serge

    2014-01-15

    The surface charge and average size of manufactured ZnO nanoparticles (NPs) were studied as a function of pH to understand the aggregation behavior and importance of the electrostatic interactions in solution. The interactions between ZnO and Suwannee River humic acid (SRHA) were then investigated under a range of environmentally relevant conditions with the ZnO nanoparticles pHPZC as the point of reference. The anionic charges carried by aquatic humic substances were found to play a major role in the aggregation and disaggregation of ZnO nanoparticles. At low concentrations of SRHA (<0.05 mg/L) and below the pHPZC, anionic SRHA was rapidly adsorbed onto the positively charged ZnO NPs hence promoting aggregation. With similar SHRA concentrations, at pHPZC, SRHA was able to control the suspension behavior of the ZnO and promote partial disaggregation in small volumes. This was more distinguishable when the pH was greater than pHPZC as SRHA formed a surface coating on the ZnO nanoparticles and enhanced stability via electrostatic and steric interactions. In most cases, the NP coating by SRHA induced disaggregation behavior in the ZnO nanoparticles and decreased the aggregate size in parallel to increasing SRHA concentrations. Results also suggest that environmental aquatic concentration ranges of humic acids largely modify the stability of aggregated or dispersed ZnO nanoparticles. © 2013.

  20. Fractionation of Suwannee River Fulvic Acid and Aldrich Humic Acid on α-Al2O3: Spectroscopic Evidence

    Energy Technology Data Exchange (ETDEWEB)

    Claret, F.; Schäfer, T; Brevet, J; Reiller, P

    2008-01-01

    Sorptive fractionation of Suwannee River Fulvic Acid (SRFA) and Purified Aldrich Humic Acid (PAHA) on a-Al2O3 at pH 6 was probed in the supernatant using different spectroscopic techniques. Comparison of dissolved organic carbon (DOC) analysis with UV/vis spectrophotometric measurements at 254 nm, including specific UV absorbance (SUVA) calculation, revealed a decrease in chromophoric compounds for the nonsorbed extracts after a 24 h contact time. This fractionation, only observable below a certain ratio between initial number of sites of humic substances and of a-Al2O3, seems to indicate a higher fractionation for PAHA. C(1s) near-edge X-ray absorption fine structure spectroscopy (NEXAFS) confirmed this trend and points to a decrease in phenolic moieties in the supernatant and to an eventual increase in phenolic moieties on the surface. Time-resolved luminescence spectroscopy (TRLS) of Eu(III) as luminescent probe showed a decrease in the ratio between the 5D0?7F2 and 5D0?7F1 transitions for the fractionated organic matter (OM) that is thought to be associated with a lower energy transfer from the OM to Eu(III) due to the loss of polar aromatics. These modifications in the supernatant are a hint for the modification of sorbed humic extracts on the surface.

  1. Reduction of Ammonia Volatilization through Mixing Urea with Humic and Fulvic Acids isolated from Palm Oil Mill Effluent Sludge

    OpenAIRE

    Shamsuddin Rosliza; Osumanu H. Ahmed; Nik M.A. Majid; Mohamadu B. Jalloh

    2009-01-01

    Problem statement: Ammonia volatilization from surface-applied urea may be substantial but it is possible to control it by mixing urea with acidic substances such as Humic Acids (HA) and Fulvic Acids (FA). The objective of this study was to compare the effects of urea-HA, urea-FA, urea-acidified (HA+FA) mixtures on ammonia loss, soil pH, soil exchangeable ammonium and available nitrate accumulation compared to urea alone. Approach: The effects of urea amended with or without HA and FA were ev...

  2. Nordic seminar on biomass gasification and combustion

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-12-31

    The report comprises a collection of papers from a seminar arranged as a part of the Nordic Energy Research Program. The aim of this program is to strengthen the basic competence in the energy field at universities and research organizations in the Nordic countries. In the program 1991-1994 six areas are selected for cooperation such as energy and society, solid fuels, district heating, petroleum technology, bioenergy and environment, and fuel cells. The topics deal both with biomass combustion and gasification, and combustion of municipal solid waste (MSW) and refuse derived fuel (RDF). A number of 11 papers are prepared. 97 refs., 91 figs., 11 tabs.

  3. Fuel Cell Seminar, 1992: Program and abstracts

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-31

    This year`s theme, ``Fuel Cells: Realizing the Potential,`` focuses on progress being made toward commercial manufacture and use of fuel cell products. Fuel cell power plants are competing for market share in some applications and demonstrations of market entry power plants are proceeding for additional applications. Development activity on fuel cells for transportation is also increasing; fuel cell products have potential in energy and transportation industries, with very favorable environmental impacts. This Seminar has the purpose of fostering communication by providing a forum for the international community interested in development, application, and business opportunities related fuel cells. Over 190 technical papers are included, the majority being processed for the data base.

  4. All India Seminar on Biomedical Engineering 2012

    CERN Document Server

    Bhatele, Mukta

    2013-01-01

    This book is a collection of articles presented by researchers and practitioners, including engineers, biologists, health professionals and informatics/computer scientists, interested in both theoretical advances and applications of information systems, artificial intelligence, signal processing, electronics and other engineering tools in areas related to biology and medicine in the All India Seminar on Biomedical Engineering 2012 (AISOBE 2012), organized by The Institution of Engineers (India), Jabalpur Local Centre, Jabalpur, India during November 3-4, 2012. The content of the book is useful to doctors, engineers, researchers and academicians as well as industry professionals.

  5. Glasses and grains : Poincaré seminar

    CERN Document Server

    Rivasseau, Vincent; Duplantier, Bertrand

    2011-01-01

    This tenth volume in "The Poincare Seminar Series" describes recent developments at one of the most challenging frontiers in statistical physics - the deeply related fields of glassy dynamics, especially near the glass transition, and of the statics and dynamics of granular systems. These fields are marked by a vigorous interchange between experiment, theory, and numerical studies, all of which are well represented by the leading experts who have contributed articles to this volume. These articles are also highly pedagogical, as befits their origin in lectures to a broad scientific a

  6. Psychotoxic Substances

    Science.gov (United States)

    1964-11-16

    substances, such as chlorpromazine , reserpine, meprobamate, and 1,2,3,4-tetrahydro-9-amino- acridine. From the results which have been arrived at up... synthesis - 32 - of structural and functional elements, such as proteins, lipids, or trans- mitter substances. Table 28/6 Influence of the Replacement

  7. 77 FR 24613 - Significant New Use Rules on Certain Chemical Substances

    Science.gov (United States)

    2012-04-25

    ...). Recommended testing: EPA has determined that the results of a fish acute toxicity mitigated by humic acid test... the PMN substance. PMN Number P-05-714 Chemical name: Polyether ester acid compound with a polyamine... Number P-07-537 Chemical name: Alkanenitrile, bis(cyanoalkyl)amino (generic). CAS number: Not available...

  8. Strategies and Tactics for Community Mobilization. 1981 Latin America Seminars.

    Science.gov (United States)

    Dobson, John R. A.

    Three seminars examined strategies and tactics for community mobilization in Latin America. The sessions--which were held in Bogota, Columbia; Quito, Ecuador; and Recife, Brazil--involved a total of 75 participants from 27 organizations. Addressed during the seminars were development, leadership, mobilization, and learning in the context of…

  9. Algorithmic Methods for Optimization in Public Transport (Dagstuhl Seminar 16171)

    OpenAIRE

    Kroon, Leo G.; Schöbel, Anita; Wagner, Dorothea

    2016-01-01

    This report documents the talks and discussions at the Dagstuhl seminar 16171 “Algorithmic Methods for Optimization in Public Transport”. The seminar brought together researchers from algorithm, algorithm engineering, operations research, mathematical optimization and engineering, all interested in algorithms in public transportation. Also several practitioners were able to join the group and brought valuable insights on current practice and challenging problems.

  10. 2015 Cross-Domain Deterrence Seminar Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Juarez, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-01-11

    Lawrence Livermore National Laboratory (LLNL) hosted the 2nd Annual Cross-Domain Deterrence Seminar on November 17th, 2015 in Livermore, CA. The seminar was sponsored by LLNL’s Center for Global Security Research (CGSR), National Security Office (NSO), and Global Security program. This summary covers the seminar’s panels and subsequent discussions.

  11. Organizing a Campus Seminar on Careers in Entertainment.

    Science.gov (United States)

    Walt Disney Productions, Anaheim, CA.

    Developed by Walt Disney Productions as part of a project granted by the Career Education Program of the Office of Education, this handbook is designed to help college and university fine arts departments in planning and carrying out an on-campus seminar on careers in entertainment. Sections include Why Hold a Seminar on Careers in Entertainment?,…

  12. A Course in Heterogeneous Catalysis Involving Video-Based Seminars.

    Science.gov (United States)

    White, Mark G.

    1984-01-01

    A video-based format was used during a graduate seminar course designed to educate students on the nature of catalysis, to help transfer information among students working on similar problems, and to improve communication skills. The mechanics of and student reaction to this seminar course are discussed. (JN)

  13. Teaching Controversy by Seminar: An Example in Quaternary Geomorphology.

    Science.gov (United States)

    Harwood, Doug

    1987-01-01

    Describes how seminar work can be structured to help students develop skills of critical thinking and expression when discussing controversial issues in their chosen subject. Particular emphasis is given to methods of organizing instructional materials and appropriate roles for seminar leaders. The debate surrounding the existence of a prehistoric…

  14. Impressions from the 3rd Nordcode Seminar & Workshop

    DEFF Research Database (Denmark)

    Lenau, Torben Anker; Boelskifte, Per; Hansen, Claus Thorp

    2005-01-01

    This paper summarises the purpose and contents of the 3rd Nordcode Seminar and Workshop. First, the workshop assignments are described. Second, the paper briefly presents the topics of the keynote speeches and all presentations of the working papers that took place in the seminar....

  15. Interaction and Collective Movement Processing : Report from Dagstuhl Seminar 14132

    NARCIS (Netherlands)

    2014-01-01

    This report documents the program and the outcomes of Dagstuhl Seminar 14132 “Interaction and Collective Movement Processing”. This seminar brought together a group of 30 scientists with varied backgrounds, but with a shared interest in computations involved in the processing of moving entity data,

  16. Correct and efficient accelerator programming (Dagstuhl Seminar 13142)

    NARCIS (Netherlands)

    Cohen, Albert; Donaldson, Alistair F.; Huisman, Marieke; Katoen, Joost P.

    2013-01-01

    This report documents the program and the outcomes of Dagstuhl Seminar 13142 “Correct and Efficient Accelerator Programming”. The aim of this Dagstuhl seminar was to bring together researchers from various sub-disciplines of computer science to brainstorm and discuss the theoretical foundations,

  17. Correct and Efficient Accelerator Programming (Dagstuhl Seminar 13142)

    NARCIS (Netherlands)

    Cohen, A.; Donaldson, A.F.; Huisman, Marieke; Katoen, Joost P.

    2013-01-01

    This report documents the program and the outcomes of Dagstuhl Seminar 13142 “Correct and Efficient Accelerator Programming‿. The aim of this Dagstuhl seminar was to bring together researchers from various sub-disciplines of computer science to brainstorm and discuss the the- oretical foundations,

  18. Proceedings of the Twenty Second Nordic Seminar on Computational Mechanics

    DEFF Research Database (Denmark)

    This book contains the proceedings of the Twenty Second Nordic Seminar on Computational Mechanics (NSCM22), taking event 22-23 October 2009 at Aalborg University, Denmark. The papers presented at the Optimization Seminar in Honour of Niels Olhoff, held 21 October 2009 at Aalborg University, Denmark......, are included at the end of the proceedings....

  19. Characterization of competitive binding of Eu(III)/Cu(II) and Eu(III)/Ca(II) to Gorleben humic acid

    Energy Technology Data Exchange (ETDEWEB)

    Marang, L.; Reiller, P.E. [CEA Saclay, Lab Speciat Radionucledies and Mol, DEN, DANS, DPC, SECR, 91 - Gif sur Yvette (France); Marang, L.; Benedetti, M.F. [Univ Paris Diderot, Lab Geochim Eaux, IPGP, F-75251 Paris 05 (France); Marang, L.; Benedetti, M.F. [CNRS, UMR 71574, F-75251 Paris 05 (France); Eidner, S.; Kumke, M. [Univ Potsdam, Inst Chem, D-14476 Potsdam (Germany)

    2009-06-15

    Complete text of publication follows: In an area that contains high concentrations of natural organic matter, it is expected to play an important role on the speciation of trivalent radionuclides. Competitive interactions with H{sup +} and major cations, e.g. Ca{sup 2+} or Mg{sup 2+}, could influence these metals transport and bioavailability. Competitive experiments between Eu{sup 3+} and cations which can bind differently to humic substances, would bring an improved understanding of the competitive mechanisms. The aim of this study is to acquire data for Eu(III)/Cu(II) and Eu(III)/Ca(II) competitive binding to a sedimentary-originated humic acid (Gorleben, Germany). The NICA-Donnan parameters [1] for Ca(II), Cu(II), and Eu(III) obtained from competitive binding experiments using Ca{sup 2+} or Cu{sup 2+} ion selective electrodes (ISE), were used to model time-resolved luminescence spectroscopy (TRLS) measurements. Then the TRL spectra and decay times were interpreted to check the consistency of the modelling. From ISE data, Eu(III) and Cu(II) are in direct competition for the same type of sites, whereas Ca(II) has an indirect influence through electrostatic binding. The spectroscopic interpretation of the competition experiments showed two strikingly different environments for the Eu(III)/Cu(II) and Eu(III)/Ca(II) systems. Cu(II) seems to expel more effectively Eu(III) into an aqueous like environment within the humic acid structure, i.e., the Donnan phase, and to the aqueous phase as free Eu{sup 3+}. This is evidenced both from the spectra as well as from the decrease in the luminescence decay times. Moreover, Ca(II) causes a slighter modification of the chemical environment of the humic-complexed Eu(III). [1] Kinniburgh et al. (1999) Colloids Surf. A 151, 147-166

  20. Effect of humic acid source on humic acid adsorption onto titanium dioxide nanoparticles.

    Science.gov (United States)

    Erhayem, Mohamed; Sohn, Mary

    2014-02-01

    In many studies, different humic acid (HA) sources are used interchangeably to evaluate the effect of organic matter on geochemical processes in the environment. This research looks more specifically at the effect of HA source on HA adsorption onto nano-TiO2 and how HA adsorption affects the fate and transport of nano-TiO2. In this study, six humic acids (HAs) were studied which were derived from soils (SLHA), or from sediments (SDHA) all originating from the state of Florida. Humic acid adsorption onto titanium dioxide nanoparticles (nano-TiO2) and the sedimentation of HA-coated and uncoated nano-TiO2 were monitored by Ultraviolet-visible (UV-vis) spectroscopy. Synchronous scan fluorescence (SSF) spectroscopy was used to complement the study of HA adsorption onto nano-TiO2. Phosphate buffer was found to reduce the amount of HA adsorbed onto nano-TiO2 relative to solutions of NaCl of the same pH and ionic strength. Adsorption constant values (Kads) for HAs varied in the order SLHA>FSDHA (freshwater sedimentary HA)>ESDHA (estuarine sedimentary HA). SSF results suggested that the more highly conjugated fractions of HA, which are more prevalent in SLHAs versus SDHAs, were preferentially adsorbed. In order to better understand the relationship between adsorption and aggregation, sedimentation studies were conducted and it was found that the percentage of nano-TiO2 sedimentation was preferentially enhanced in the order of the presence of SLHA>FSDHA>ESDHA. The extent of nano-TiO2 sedimentation was decreased with increasing HA concentration. TEM imaging of nano-TiO2 confirmed that nano-TiO2 was aggregated in the presence of HAs. The findings in this study suggest that HAs from different sources influence the fate and transport of nano-TiO2 in the environment differently. © 2013.

  1. A seminar course on contemporary pharmacy issues.

    Science.gov (United States)

    Poirier, Therese I

    2008-04-15

    To implement and evaluate an innovative approach to a pharmacy seminar course intended to develop students' presentation skills and encourage them to think critically about contemporary pharmacy issues. The instructor provided lectures intended to prepare students for their presentations. These lectures included tips on writing abstracts, learning objectives, use of visual aids, and presentation delivery. Pairs of students chose a pharmacy issue, researched their topic including identifying various strengths of evidence to support a perspective, wrote an abstract and learning objectives, prepared their visual aids, and delivered a pro/con perspective. Students also provided peer evaluations for these presentations. A personal response system was used to provide class input on the presentations. Ninety-five percent of the peer evaluations of the presentations were good to excellent. The overall course evaluations indicated achievement of course goals. A pharmacy seminar course intended to develop student presentation skills and critical thinking about contemporary pharmacy issues was demonstrated to be successful. The "taking sides" format was an effective design for accomplishing these objectives.

  2. Geneva University - Next Particle Physics Seminars

    CERN Multimedia

    Université de Genève

    2010-01-01

    GENEVA UNIVERSITY École de physique Département de physique nucléaire et corspusculaire 24, quai Ernest-Ansermet 1211 GENEVA 4 Tel. (022) 379 62 73 Fax (022) 379 69 92 Wednesday 17 November 2010 PARTICLE PHYSICS SEMINAR at 17-00 hrs – Stückelberg Auditorium Results on CP-Violation in The B_s and B_d systems at the Tevatron Dr. Iain Bertram, Lancaster Results will be presented from the investigation of CP-violation in B mesons at the Tevatron. The evidence for an anomalous likes-sign dimuon charge asymmetry will be presented, along with the latest results on CP violation in the Bs -> J/Psi Phi system. The implications of these results and the possibility of confirming them in the future will also be discussed. Information : http://dpnc.unige.ch/seminaire/annonce.html Organizer : G. Pasztor Wednesday 1st December 2010 PARTICLE PHYSICS SEMINAR at 17-00 hrs – Stückelberg Auditorium PAMELA - A COSMIC RAY OBSERVATO...

  3. Programme of Seminars September to December 2003

    CERN Multimedia

    2003-01-01

    Dates Jours/ Days Places Disponibles*/ Places Available* Séminaires bilingues/Bilingual seminars Gestion de la qualité/Quality Management 10, 11, 12 November 3 oui Managing a CERN unit - to be a Manager/ Gérer une unité au CERN - Etre Manager (Module 3) 11, 12 November 2 non Gestion des risques /Risk Management 11, 12 December 2 oui Seminars in English Communicating effectively in your team 19, 20 November 2 yes Performance Appraisal Training MAPS 26, 27, 28 November 3 yes Managing by Project 3, 4 December 3 no Making Presentations 1, 2 December & 12 January 2004 3 yes Performance Appraisal Training MAPS 8, 9, 10 December 3 no Séminaires en Français Formation à l'entretien d'appréciation MAPS 26, 27, 28 novembre 3 non Formation à l'entretien d'appréciation MAPS 8, 9, 10 décembre 3 oui Animer ou participer à une ré...

  4. Wind Turbine Tribology Seminar - A Recap

    Energy Technology Data Exchange (ETDEWEB)

    Errichello, R.; Sheng, S.; Keller, J.; Greco, A.

    2012-02-01

    Tribology is the science and engineering of interacting surfaces in relative motion. It includes the study and application of the principles of friction, lubrication, and wear. It is an important phenomenon that not only impacts the design and operation of wind turbine gearboxes, but also their subsequent maintenance requirements and overall reliability. With the major growth and increasing dependency on renewable energy, mechanical reliability is an extremely important issue. The Wind Turbine Tribology Seminar was convened to explore the state-of-the-art in wind turbine tribology and lubricant technologies, raise industry awareness of a very complex topic, present the science behind each technology, and identify possible R&D areas. To understand the background of work that had already been accomplished, and to consolidate some level of collective understanding of tribology by acknowledged experts, the National Renewable Energy Laboratory (NREL), Argonne National Laboratory (ANL), and the U.S. Department of Energy (DOE) hosted a wind turbine tribology seminar. It was held at the Renaissance Boulder Flatiron Hotel in Broomfield, Colorado on November 15-17, 2011. This report is a summary of the content and conclusions. The presentations given at the meeting can be downloaded. Interested readers who were not at the meeting may wish to consult the detailed publications listed in the bibliography section, obtain the cited articles in the public domain, or contact the authors directly.

  5. Seminar on Detectors and measurements techniques

    Energy Technology Data Exchange (ETDEWEB)

    Holm, E. (ed.) [Risoe National Lab., Roskilde (Denmark)

    2002-07-01

    A Nordic Seminar on detectors and radionuclide measurement techniques was held in Lund, Sweden, May 3-4, 2001. The objective was to highlight recent progress and problems for techniques to study environmental radioactivity. It covered the aspect of detector sample geometry's and methods for evaluation of gamma gamma pulse height distributions. Within the field of alpha-spectrometric techniques gridded ionisation chambers, semiconductor detectors and a general description for analysis of alpha-particle-spectra were presented. Recent development in mass spectrometric techniques, AMS (Accelerator Mass Spectrometry) and ICPMS (Inductively Coupled Plasma mass Spectrometry) for long-lived radionuclides was described. Principles for analysis of beta particle emitters, especially by liquid scintillation were presented. The seminar also covered radiochemistry such advantages and disadvantages between ion exchange, solvent extraction and extraction chromatography. The use of controlled laboratory conditions for discerning the dynamics of accumulation in organisms was demonstrated. Other techniques such as neutron activation were also shown to be useful analytical tool for certain long-lived radionuclides. The results of the intercalibration exercises within the Nordic countries showed the importance of such analytical quality control. (au)

  6. Monitoring patient rights--a clinical seminar.

    Science.gov (United States)

    Shalev, Carmel; Freiman, Efrat

    2002-01-01

    Israel enacted the Patient Rights Law in 1996. The Law embodies a movement from paternalism to autonomy in doctor-patient relations. The following year, law students at the Israeli Centre for Academic Studies participated in a clinical seminar designed to measure internalisation ofthe Law, through personal interviews with hospitalized patients. The seminar can be adapted for medical students. The methodology is taken from human rights field work. The objective is to use patient rights as indicators of quality of care in medical settings. Students studied the text and principles of the Law in light of personal testimonies taken from relatives and friends. They developed an open-structured questionnaire, and were trained in interviewing with due respect for the patients' dignity and privacy, and the need to obtain their free and informed consent to the interview. The interviews were conducted in Hadassah Hospital, Jerusalem, after receiving approval of the Helsinki Committee. The findings, though in no way statistically valid, are nonetheless interesting. Students received training in listening and advocacy skills. The approach is conciliatory rather than adversarial. The thesis is that respect for patient rights is an efficient tool for quality control, risk management, conflict resolution and prevention of litigation.

  7. [Adsorption characteristics and mechanism of atrazine on three types of humic acid].

    Science.gov (United States)

    Chang, Chun-ying; Zheng, Yin-tian; Lü, Yi-zhong

    2010-10-01

    This study mainly researched the adsorption properties and adsorption mechanism of atrazine on three different types of humic acids: the black soil humic acid, the chestnut soil humic acid and the humic acid purchased. After the extraction of humic acid from the two different types of soil, the black soil and chestnut soil, adsorption experiments were carried out using the batch equilibrium techniques. Then FTIR and ESR spectral analysis methods were employed to explain the functional mechanism between atrazine and humic acid. The results showed that the sorption of humic acid on atazine was very fast at the beginning, then went to slower and finally came to equilibrium. The relationship between the amount of atrazine sorbed by the three humic acids and reaction time all fitted logarithmic and hyperbolic equations well. Adsorption isotherms of atrazine on the three humic acids all are L-type and in accordance with the linear model and the Freundlich model. Because of the different structure, there is significant difference between the adsorption isotherm of atrazine on purchased humic acid and extract humic acid. The interactions between humic acid and atrazine are mostly weak forces, such as the H-bond, proton transfer, charge transfer, van der Waals force and so on. In addition, ESR analysis proved that charge transfer exists between humic acid and atrazine during the process of adsorption.

  8. Formulation of humic-based soil conditioners

    Science.gov (United States)

    Amanova, M. A.; Mamytova, G. A.; Mamytova, B. A.; Kydralieva, K. A.; Jorobekova, Sh. J.

    2009-04-01

    The goal of the study is to prepare soil conditioners (SC) able to carry out the following functions: (i) the chemical conditioning of soil mainly comprising the adjustment of pH, (ii) the balancing of inorganic nutrients, (iii) the physical conditioning of soil mainly comprising the improvement of water permeability, air permeability and water retention properties, and (iv) improvement of the ecological system concerning of useful microorganisms activity in the soil. The SC was made of a mixture of inorganic ingredients, a chemical composition and physical and chemical properties of which promoted improvement of physical characteristic of soil and enrichment by its mineral nutritious elements. In addition to aforesaid ingredients, this soil conditioner contains agronomical-valued groups of microorganisms having the function promoting the growth of the crop. As organic component of SC humic acids (HA) was used. HA serve many major functions that result in better soil and plant health. In soil, HA can increase microbial and mycorrhizal activity while enhancing nutrient uptake by plant roots. HA work as a catalyst by stimulating root and plant growth, it may enhance enzymatic activity that in turn accelerates cell division which can lead to increased yields. HA can help to increase crop yields, seed germination, and much more. In short, humic acids helps keep healthy plants health. The first stage goal was to evaluate mineral and organic ingredients for formulation of SC. Soil conditioners assessed included ash and slag. The use of slags has been largelly used in agriculture as a source of lime and phosphoric acid. The silicic acid of slags reduces Al-acitivity thus, promoting a better assimilation of P-fertilizer by plants. Additionally, silicic acid is also known to improve soil moisture capacity, thus enhancing soil water availability to plants. Physico-chemical characteristics of ash and slag were determined, as a total - about 20 samples. Results include

  9. Luminescence from {gamma}-irradiated humic acid

    Energy Technology Data Exchange (ETDEWEB)

    Goraczko, Wieslaw [Faculty of Chemical Technology, Radio- and Photochemistry Department, Poznan University of Technology, ul. Piotrowo 3, 60-965 Poznan (Poland)], E-mail: wieslaw.goraczko@put.poznan.pl; Slawinski, Janusz [Institute of Ecotechnology, State Higher Vocational School, ul. Ks. Kard. S.Wyszynskiego 38, 62-200 Gniezno (Poland)

    2008-07-15

    This study was conducted to investigate the ultraweak delayed radiochemiluminescence (RCL) spectra, kinetics and spectroscopic properties of humic acids (HAs) after {gamma}-radiation exposure (absorbed doses of 1-10 kGy, Co-60) in model systems. The kinetics and spectral distribution of RCL (340-650 nm) were measured using the single photon counting (SPC) method and cut-off filters. The intensity of fluorescence ({lambda}{sub ex}=390, 440, 490 and 540 nm) covering the spectral range 400-580 nm was heavily dependent on the {lambda}{sub ex} and slightly increased with the absorbed dose of {gamma}-radiation. Absorption spectra (the range 240-800 nm) and color coefficients E{sub 2.6/4} and E{sub 4/6} of irradiated solutions indicated that post-radiative degradation/polymerization processes take place in the HA, changing their macromolecule size or properties. Comparison of FTIR spectra and elemental analysis proved an increased O and decreased C atoms in irradiated samples. The data indicate on the radiolysis-induced degradation of native HA into fulvic-like acids with higher hydrophilicity and lower molecular size.

  10. Seminar on waste treatment and disposal; Seminar po obrashcheniyu s otkhodami i ikh utilizatsii

    Energy Technology Data Exchange (ETDEWEB)

    Sneve, Malgorzata Karpow; Snihs, Jan Olof

    1999-07-01

    A seminar on radioactive waste treatment and disposal was held 9 - 14 November 1998 in Oskarshamn, Sweden. The objective of the seminar was to exchange information on national and international procedures, practices and requirements for waste management. This information exchange was intended to promote the development of a suitable strategy for management of radioactive waste in Northwest Russia to be used as background for future co-operation in the region. The seminar focused on (1) overviews of international co-operation in the waste management field and national systems for waste management, (2) experiences from treatment of low- and intermediate-level radioactive waste, (3) the process of determining the options for final disposal of radioactive waste, (4) experiences from performance assessments and safety analysis for repositories intended for low- and intermediate level radioactive waste, (5) safety of storage and disposal of high-level waste. The seminar was jointly organised and sponsored by the Swedish Radiation Protection Institute (SSI), the Norwegian Radiation Protection Authority (NRPA), the Nordic Nuclear Safety Research (NKS) and the European Commission. In brief, the main conclusions are: (1) It is the prerogative of the Russian federal Government to devise and implement a waste management strategy without having to pay attention to the recommendations of the meeting, (2) Some participants consider that many points have already been covered in existing governmental documents, (3) Norway and Sweden would like to see a strategic plan in order to identify how and where to co-operate best, (4) There is a rigorous structure of laws in place, based on over-arching environmental laws, (5) Decommissioning of submarines is a long and complicated task, (6) There are funds and a desire for continued Norway/Sweden/Russia co-operation, (7) Good co-operation is already taking place.

  11. Chemical modeling of boron adsorption by humic materials using the constant capacitance model

    Science.gov (United States)

    The constant capacitance surface complexation model was used to describe B adsorption behavior on reference Aldrich humic acid, humic acids from various soil environments, and dissolved organic matter extracted from sewage effluents. The reactive surface functional groups on the humic materials wer...

  12. Seminar on building codes and standards

    Energy Technology Data Exchange (ETDEWEB)

    1980-01-01

    A seminar was conducted for state building code officials and state energy officials to discuss the following: status of the states regulatory activities for energy conservation standards for buildings; the development, administration, and enforcement processes for energy conservation standards affecting new construction; lighting and thermal standards for existing buildings; status of the development and implementation of the Title III Program, Building Energy Performance Standards (BEPS); and current status of the State Energy Conservation Program. The welcoming address was given by John Wenning and the keynote address was delivered by John Millhone. Four papers presented were: Building Energy Performance Standards Development, James Binkley; Lighting Standards in Existing Buildings, Dorothy Cronheim; Implementation of BEPS, Archie Twitchell; Sanctions for Building Energy Performance Standards, Sue Sicherman.

  13. Biological Physics : Poincaré seminar

    CERN Document Server

    Bio-physique : séminaire Poincaré

    2011-01-01

    This new volume in the Poincaré Seminar Series, describing recent developments at the interface between physics and biology, is directed towards a broad audience of physicists, biologists, and mathematicians. Both the theoretical and experimental aspects are covered, and particular care is devoted to the pedagogical nature of the presentations. The first survey article, by Jean-Francois Joanny and Jacques Prost, describes the theoretical advances made in the study of "active gels", with applications to liquid crystals and cell motility. Jasper van der Gucht and Cécile Sykes then report on recent advances made with biomimetic model systems in the understanding of cytokinesis. The next article, by Jonathon Howard, presents several molecular models for motor proteins, which are compared with experimental results for kinesin. David Lacoste and Kirone Mallick then show theoretically that similar ratchet models of motor proteins naturally satisfy a fundamental time-reversal symmetry, the Gallavotti-Cohen fluctuat...

  14. 17th Poincaré Seminar 2013

    CERN Document Server

    Duplantier, Bertrand; Raimond, Jean-Michel; Rivasseau, Vincent

    2016-01-01

    This fourteenth volume in the Poincaré Seminar Series is devoted to Niels Bohr, his foundational contributions to understanding atomic structure and quantum theory and their continuing importance today. This book contains the following chapters: - Tomas Bohr, Keeping Things Open; - Olivier Darrigol, Bohr's Trilogy of 1913; -John Heilbron, The Mind that Created the Bohr Atom; - Serge Haroche & Jean-Michel Raimond, Bohr's Legacy in Cavity QED; - Alain Aspect, From Einstein, Bohr, Schrödinger to Bell and Feynman: a New Quantum Revolution?; - Antoine Browaeys, Interacting Cold Rydberg Atoms: A Toy Many-Body System; - Michel Bitbol & Stefano Osnaghi, Bohr´s Complementarity and Kant´s Epistemology. Dating from their origin in lectures to a broad scientific audience these seven chapters are of high educational value. This volume is of general interest to physicists, mathematicians and historians.

  15. The role of humic acids and biochar as specific sorbents of pesticides in soil

    Science.gov (United States)

    Ćwieląg-Piasecka, Irmina; Dębicka, Magdalena; Medyńska-Jureszek, Agnieszka; Weber, Jerzy; Jamroz, Elżbieta

    2017-04-01

    Pesticides are widely used in agriculture to prevent or control different pests and increase yield as well as products quality. Despite of the strict regulations concerning sustainable use of plant protection products, their residues are very often present in soil. Depending on their chemical and physical properties, they undergo various transformations in the soil. This results in their retention on different sorbents, degradation by microorganisms or leaching to the groundwater. Biochar is a carbon-rich byproduct of thermal biomass conversion, and due to its high sorption properties can be an efficient sorbent for pesticides in soil. The aim of the research was to compare the effect of two types of organic sorbents - humic acids (HA) and biochar (BC) - in sorption-desorption processes of different pesticides, which residues are commonly present in arable soils and thus are potentially harmful for the environment. The humic acids were extracted from topsoil horizon of arable cambisoil derived from loam (Lower Silesia, Poland) by Shnitzer's method, then purified using XAD resin and freeze-dried. Biochar was produced from wheat straw in gasification process at 550˚C, remaining 30 minutes in the reactor. Investigated pesticides belong to three different chemical classes: carbamates (carbaryl and carbofuran), phenoxyacetic acids (2,4-D and MCPA) and aniline derivatives (metolachlor), and are active substances of commonly used plant protection products in agriculture. To obtain the experimental goal the sorption experiment was conducted. To the investigated organic matter samples (HA or BC) aliquots of pesticides solutions in 10M CaCl2 were added and the mixtures were shaken for 24h. Afterwards the samples were centrifuged and supernatants analyzed by LC-MS/MS for the pesticides content. After that the same samples were refilled with CaCl2 and analyzed in the same way for desorption studies. Humic acids exhibited strong affinity for the ionic substances (2,4-D, MCPA

  16. Chlorination of humic materials: Byproduct formation and chemical interpretations

    Science.gov (United States)

    Reckhow, D.A.; Singer, P.C.; Malcolm, R.L.

    1990-01-01

    Ten aquatic humic and fulvic acids were isolated and studied with respect to their reaction with chlorine. Yields of TOX, chloroform, trichloroacetic acid, dichloroacetic acid, dichloroacetonitrile, and 1,1,1-trichloropropanone were measured at pH 7 and 12. Humic acids produced higher concentrations than their corresponding fulvic acids of all byproducts except 1,1,1-trichloropropanone. Chlorine consumption and byproduct formation were related to fundamental chemical characteristics of the humic materials. A statistical model was proposed for activated aromatic content based on 13C NMR and base titration data. The values estimated from this model were found to be well correlated with chlorine consumption. Specific byproduct formation was related to UV absorbance, nitrogen content, or the activated aromatic content. ?? 1990 American Chemical Society.

  17. Thermodynamics of Molybdate Binding to Humic Acid

    Science.gov (United States)

    Thalhammer, K.; Gilbert, B.

    2016-12-01

    Molybdenum is an essential nutrient for diazotrophic bacteria that use nitrogenase I to fix atmospheric nitrogen in soils into bioavailable forms such as ammonia. This metalloid is released during rock weathering processes and at neutral pH it exists primarily as the soluble oxyanion molybdate, MoO42-. It has been established that molybdate mobility and bioavailability in soils is influenced by sorption to mineral surfaces and complexation by natural organic matter (NOM). The molybdate ion is readily bound by ortho dihydroxybenzene molecules such as catechol and catechol groups in siderophores. Humic acids (HA) found in NOM contain abundant phenolic groups and extended X-ray absorption fine structure (EXAFS) spectroscopy demonstrated that molybdate is bound by catechol-containing molecules in soil organic matter1. However, to our knowledge no quantitative determination of the affinity of molybdate to HA has been reported. We studied the interactions of molybdate with Suwannee River HA using ultraviolet-visible (UV-vis) absorption spectroscopy and isothermal titration calorimetry (ITC) to determine the conditional equilibrium constant for complexation at neutral pH. We further used ITC to investigate the thermodynamic contributions to complexation and the interaction kinetics. Addition of molybdate to HA caused the formation of complexes with UV-vis absorption spectra in good agreement with molybdate-catechol species indicating catechol groups to be the primary ligands in HA. ITC data revealed that binding enthalpies and kinetics were strongly influenced by ionic strength, suggesting a role for macromolecular reorganization driven by metalloid addition. 1. Wichard et al., Nature Geoscience 2, 625 - 629 (2009).

  18. Possibilities of using humic acid in diets for Saanen goats

    Directory of Open Access Journals (Sweden)

    Taskin Degirmencioglu

    2012-12-01

    Full Text Available This study was carried out to determine the effect of diets containing humic acid at different levels on some blood and milk components in Saanen goats. Saanen goats (2 years old, 52 kg live body weight were fed three diets, containing 0 g kg-1 humic acid (T1, 1 g kg-1 humic acid (T2 and 3 g kg-1 humic acid (T3 in a 3x3 Latin square design experiment. Compared to the control group, T1 - treated group produced more milk/day (P<0.05; 2.45 vs. 2.11 kg d-1 and this yield was similar to that of T2 - treated group. The fat (3.55, 3.67 and 3.58 %, non-fat solids (SNF (8.41, 8.30 and 8.58 %, protein (3.73, 3.60 and 3.92 % and lactose percentages of milk (3.82, 3.83 and 3.77 were similar for T1, T2 and T3 groups. Humic acid administration significantly reduced total cholesterol in blood (P<0.05; 124.1, 100.8 and 102.2 mg dL-1 for T1, T2 and T3, respectively. The LDL cholesterol levels in blood serum of T1, T2 and T3 groups were 23.49, 15.14 and 16.19 mg dL-1, respectively (P<0.05. Further investigation is required to elucidate the effects of humic acid on goat performance.

  19. Isolation and characterization of aquatic humic acid and fulvic acid

    Energy Technology Data Exchange (ETDEWEB)

    Rhee, D.S. [Kangwon National University, Chunchon (Korea)

    2002-02-01

    The dissolved organic carbon extracted from groundwater is separated into humic acid and fulvic acid. They are characterized for their chemical composition, spectroscopic characteristics using UV/VIS, IR and solid state {sup 13}C-NMR spectroscopy, proton exchange capacity and molecular size distribution. The results are comparable with the literature data. The study explains that the aquatic humic and fulvic acid in this experiment are site-specipic and polydisperse natural organic matter with considerable proton exchange capacity. (author). 16 refs., 5 tabs., 4 figs.

  20. Adsorption of humic acid and Eu(III) to multi-walled carbon nanotubes. Effect of pH, ionic strength and counterion effect

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Q.H. [Chinese Academy of Sciences, Hefei (China). Key Lab. of Novel Thin Film Solar Cell; Lanzhou Univ. (China). Radiochemistry Lab.; Shao, D.D.; Hu, J.; Chen, C.L.; Wang, X.K. [Chinese Academy of Sciences, Hefei (China). Key Lab. of Novel Thin Film Solar Cell; Wu, W.S. [Lanzhou Univ. (China). Radiochemistry Lab.

    2009-07-01

    Carbon nanotubes (CNTs) have come under intense multidisciplinary study because of their unique physicochemical properties. Understanding adsorptive interactions of simultaneous humic substances (HS) and radionuclides on CNTs is critical to understand the pollution of radionuclides and the assessment of potential impact of CNTs on the behavior of HS and radionuclides. In this paper, the adsorption of humic acid (HA) and Eu(III) on multi-walled carbon nanotubes (MWCNTs) are studied as a function of pH and ionic strength. The results indicate that the adsorption of Eu(III) and HA on MWCNTs is strongly dependent on pH and ionic strength, and the presence of HA enhances Eu(III) adsorption to HA-MWCNT hybrids. The XPS analysis indicates that the functional groups of HA contribute to Eu(III) adsorption to MWCNTs. (orig.)