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Sample records for degrade humic acid-sorbed

  1. 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

  2. Influence of humic acid on the trichloroethene degradation by Dehalococcoides-containing consortium

    International Nuclear Information System (INIS)

    Hu Miao; Zhang Ying; Wang Zhigang; Jiang Zhao; Li Juan

    2011-01-01

    By taking an anaerobic Dehalococcoides-containing consortium (designated UC-1) as the research object, the influence of humic acid on the degradation of TCE by UC-1 was examined. The results indicated that (i) TCE was more rapidly degraded in the presence of humic acid compared with the control and the TCE removal efficiencies increased with the increase of concentrations of humic acid; and (ii) at the end of experiments, in the presence of humic acid, much more ethene was produced compared with the control, whereas less VC was accumulated in the medium. Presumably, humic acid improves the activity of organisms in dechlorinating populations resulting in more ethene accumulated in the medium, and (iii) the degradation of TCE stimulated by humic acid by UC-1 might be a biotic process or an abiotic process. Thus, humic acid could influence the degradation of TCE by UC-1 directly via enhancing electron transfer between UC-1 and TCE. This work is a preliminary step for accelerating the degradation of TCE in the groundwater environment using a kind of natural organic matter - humic acid.

  3. TiO(2)-assisted photocatalytic degradation of humic acids: effect of copper ions.

    Science.gov (United States)

    Uyguner, C S; Bekbolet, M

    2010-01-01

    The present study investigated the removal efficiency of aqueous humic acid solutions by TiO(2) photocatalytic degradation in the presence of Cu(II) species. The pseudo-first-order kinetics revealed rate constants as 9.87 x 10(-3), 7.19 x 10(-3), 3.81 x 10(-3) min(-1) for Color(436), UV(254) and TOC, respectively. Comparatively, lower rate constants were attained with respect to photocatalytic degradation of humic acid. Considering the source-dependent diverse chemical and spectral characteristics of NOM, a particular interaction would be expected for humic acid with Cu(II) species (0.1 mg L(-1)). The presence of copper ions significantly altered the photocatalytic degradation kinetics of humic acids in relation to the concentration effects of humic acid as expressed by spectroscopic parameters and TOC. Batch equilibrium adsorption experiments revealed a distinct Langmuirian-type adsorptive behavior of humic acid onto TiO(2) both in terms of UV(254) and Color(436) and a C-type adsorption isotherm was attained for TOC. K(F) values displayed an inconsistent effect of Cu(II) species, while adsorption intensity factor 1/ncopper ions and humic molecular size fractions, spectroscopic techniques were also employed for the assessment of the adsorption as well as photocatalytic degradation efficiencies.

  4. Anaerobic degradation of benzene by enriched consortia with humic acids as terminal electron acceptors

    Energy Technology Data Exchange (ETDEWEB)

    Cervantes, Francisco J., E-mail: fjcervantes@ipicyt.edu.mx [Division de Ciencias Ambientales, Instituto Potosino de Investigacion Cientifica y Tecnologica (IPICyT), Camino a la Presa San Jose 2055, Col. Lomas 4a. Seccion, San Luis Potosi, SLP, 78216 Mexico (Mexico); Mancilla, Ana Rosa; Toro, E. Emilia Rios-del [Division de Ciencias Ambientales, Instituto Potosino de Investigacion Cientifica y Tecnologica (IPICyT), Camino a la Presa San Jose 2055, Col. Lomas 4a. Seccion, San Luis Potosi, SLP, 78216 Mexico (Mexico); Alpuche-Solis, Angel G.; Montoya-Lorenzana, Lilia [Division de Biologia Molecular, Instituto Potosino de Investigacion Cientifica y Tecnologica (IPICyT), Camino a la Presa San Jose 2055, Col. Lomas 4a. Seccion, San Luis Potosi, SLP, 78216 Mexico (Mexico)

    2011-11-15

    Highlights: {yields} Enriched consortia were able to couple the anaerobic degradation of benzene to the reduction of humic acids. {yields} Electron-equivalents derived from anaerobic benzene oxidation were highly recovered as reduced humic acids. {yields} Several species from classes {beta}-, {delta}- and {gamma}-Proteobacteria were enriched during the anaerobic degradation of benzene. - Abstract: The anaerobic degradation of benzene coupled to the reduction of humic acids (HA) was demonstrated in two enriched consortia. Both inocula were able to oxidize benzene under strict anaerobic conditions when the humic model compound, anthraquinone-2,6-disulfonate (AQDS), was supplied as terminal electron acceptor. An enrichment culture originated from a contaminated soil was also able to oxidize benzene linked to the reduction of highly purified soil humic acids (HPSHA). In HPSHA-amended cultures, 9.3 {mu}M of benzene were degraded, which corresponds to 279 {+-} 27 micro-electron equivalents ({mu}Eq) L{sup -1}, linked to the reduction of 619 {+-} 81 {mu}Eq L{sup -1} of HPSHA. Neither anaerobic benzene oxidation nor reduction of HPSHA occurred in sterilized controls. Anaerobic benzene oxidation did not occur in soil incubations lacking HPSHA. Furthermore, negligible reduction of HPSHA occurred in the absence of benzene. The enrichment culture derived from this soil was dominated by two {gamma}-Proteobacteria phylotypes. A benzene-degrading AQDS-reducing enrichment originated from a sediment sample showed the prevalence of different species from classes {beta}-, {delta}- and {gamma}-Proteobacteria. The present study provides clear quantitative demonstration of anaerobic degradation of benzene coupled to the reduction of HA.

  5. Anaerobic degradation of benzene by enriched consortia with humic acids as terminal electron acceptors

    International Nuclear Information System (INIS)

    Cervantes, Francisco J.; Mancilla, Ana Rosa; Toro, E. Emilia Rios-del; Alpuche-Solis, Angel G.; Montoya-Lorenzana, Lilia

    2011-01-01

    Highlights: → Enriched consortia were able to couple the anaerobic degradation of benzene to the reduction of humic acids. → Electron-equivalents derived from anaerobic benzene oxidation were highly recovered as reduced humic acids. → Several species from classes β-, δ- and γ-Proteobacteria were enriched during the anaerobic degradation of benzene. - Abstract: The anaerobic degradation of benzene coupled to the reduction of humic acids (HA) was demonstrated in two enriched consortia. Both inocula were able to oxidize benzene under strict anaerobic conditions when the humic model compound, anthraquinone-2,6-disulfonate (AQDS), was supplied as terminal electron acceptor. An enrichment culture originated from a contaminated soil was also able to oxidize benzene linked to the reduction of highly purified soil humic acids (HPSHA). In HPSHA-amended cultures, 9.3 μM of benzene were degraded, which corresponds to 279 ± 27 micro-electron equivalents (μEq) L -1 , linked to the reduction of 619 ± 81 μEq L -1 of HPSHA. Neither anaerobic benzene oxidation nor reduction of HPSHA occurred in sterilized controls. Anaerobic benzene oxidation did not occur in soil incubations lacking HPSHA. Furthermore, negligible reduction of HPSHA occurred in the absence of benzene. The enrichment culture derived from this soil was dominated by two γ-Proteobacteria phylotypes. A benzene-degrading AQDS-reducing enrichment originated from a sediment sample showed the prevalence of different species from classes β-, δ- and γ-Proteobacteria. The present study provides clear quantitative demonstration of anaerobic degradation of benzene coupled to the reduction of HA.

  6. Degradation of humic acid and formation of formaldehyde in PEROXONE processes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K.W.; Rhee, D.S. [Kangwon National University, Chunchon (Korea)

    2001-02-01

    This research was studied the action of the coupling ozone-hydrogen peroxide on aqueous humic acid. PEROXONE process is enhanced the generation of hydroxyl radicals which is effective for degradation of organic matters. Therefore the changes of UV{sub 254} and TOC were investigated through the change of concentrations, injection time of H{sub 2}O{sub 2}, initial pH of aqueous humic acid and concentrations of radical scavenger as HCO{sub 3}{sup -} in the PEROXONE processes. And the GC/ECD was used to detect the formaldehyde formed by ozonation of humic acid. From the experimental results, concentrations and injection time of H{sub 2}O{sub 2} and initial pH in solution in the PEROXONE processes were very important for enhancing the efficiency of degradation in humic acid. The results indicated that removal efficiency of TOC was the highest when concentration of H{sub 2}O{sub 2} was 5 mg/L, injection time of H{sub 2}O{sub 2} was 5 minutes and initial pH in solution was 10.5. And presence of alkalinity in solution was reduced the efficiency of treatment. The formaldehyde were formed less PEROXONE processes than only ozone. When initial pH in solution were changed from 3.5 to 10.5, the formaldehyde were formed the highest concentration at pH 5. (author). 18 refs., 12 figs.

  7. Influence of humic acid addition on the degradation of pharmaceuticals by biofilms in effluent wastewater

    DEFF Research Database (Denmark)

    Tang, Kai; Escola Casas, Monica; Ooi, Gordon Tze Hoong

    2017-01-01

    in relation to the biodegradation of pharmaceuticals by suspended biofilm carriers adapted to polishing effluent water from a tertiary sewage treatment plant. Twelve out of 22 investigated pharmaceuticals were significantly biodegradable. The biodegradation rate constants of ten of those compounds were......The degradation of organic micropollutants in wastewater treatment is suspected to depend on co-degradation i.e. be dependent on concentrations of substrate. This complicates predicting and modelling their fate. The effect of humic acid, as a model for complex organic substrate, was investigated...

  8. Enhanced degradation of metalaxyl in Gley Humic and Dark Red Latosol

    Directory of Open Access Journals (Sweden)

    S. Papini

    2000-06-01

    Full Text Available Enhanced degradation of the fungicide metalaxyl was investigated in two soils: a gley humic (GH and a Dark Red Latosol (LE, collected at sites never exposed to the fungicide. The soil samples were treated with successive applications of metalaxyl as a commercial formulation and 14C-metalaxyl in laboratory. Metalaxyl biodegradation was analyzed during 63 days by means of radiometric techniques to verify biomineralization and degradation product formation from the applied 14C-metalaxyl. Although biomineralization (maximum of 14 and 8% in the GH and LE soils, respectively, and partial degradation (about 32 and 48%, respectively were detected in both soils, enhanced degradation was verified only in the GH soil. Results proved that metalaxyl behaves differently in soils.

  9. 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.

  10. 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.

  11. Impact of humic acid on the degradation of levofloxacin by aqueous permanganate: Kinetics and mechanism.

    Science.gov (United States)

    Xu, Ke; Ben, Weiwei; Ling, Wencui; Zhang, Yu; Qu, Jiuhui; Qiang, Zhimin

    2017-10-15

    Levofloxacin (LF) is a frequently detected fluoroquinolone in surface water, and permanganate (MnO 4 - ) is a commonly used oxidant in drinking water treatment. This study investigated the impact of humic acid (HA) on LF degradation by aqueous MnO 4 - from both kinetic and mechanistic aspects. In the absence of HA, the second-order rate constant (k) of LF degradation by MnO 4 - was determined to be 3.9 M -1  s -1 at pH 7.5, which increased with decreasing pH. In the presence of HA, the pseudo-first-order rate constant (k obs ) of LF degradation at pH 7.5 was significantly increased by 3.8- and 2.8-fold at [HA] o :[KMnO 4 ] o (mass ratio) = 0.5 and 1, respectively. Secondary oxidant scavenging and electron paramagnetic resonance tests indicated that HA could form a complex with Mn(III), a strongly oxidative intermediate produced in the reaction of MnO 4 - with HA, to induce the successive formation of superoxide radicals (O 2 - ) and hydroxyl radicals (OH). The resulting OH primarily contributed to the accelerated LF degradation, and the complex [HA-Mn(III)] could account for the rest of acceleration. The degradation of LF and its byproducts during MnO 4 - oxidation was mainly through hydroxylation, dehydrogenation and carboxylation, and the presence of HA led to a stronger destruction of LF. This study helps better understand the degradation of organic micropollutants by MnO 4 - in drinking water treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Degradation of 14C-parathion 'in vitro' by microorganisms isolated from a gley humic soil

    International Nuclear Information System (INIS)

    Andrea, M.M. de; Ruegg, E.F.

    1982-01-01

    It was determined 'in vitro' the degradation of Parathion by a bacterium and a fungus isolated from a sample of Gley Humic soil previously treated with repeated applications of the insecticide. In a qualitative colorimetric assay hydrolisis of parathion to p-nitrophenol just the bacterium gave a positive answer. In quantitative assays of 14 C-parathion degradation in culture media containing both microorganisms, organic solvents extractions resulted in organic and aqueous phases, which were analysed by liquid scintillation counting and thin-layer chromatography. In a mineral salts medium plus buffer, the bacterium and the fungus behaved differently from the control, because part of the 14 C-insecticide was metabolized to, at least, one metabolite and besides, the microorganisms presented smaller percentages of total recovery. The largest percentage of the radio carbon recovery from the extracts of the medium containing the fungus plus extract of yeast, was obtained from the aqueous phase and the existence of other metabolite was demonstrated by chromatograms of the organic phase. (Author) [pt

  13. Effect of Dissolved Humic Substances on the Photochemical Degradation Rate of 1-Aminopyrene and Atrazine

    Directory of Open Access Journals (Sweden)

    Hongtao Yuzuri

    2002-10-01

    Full Text Available Abstract: Humic substances (HS are ubiquitous in the environment, and can act as photosensitizers in the redox reactions of some photochemical processes. The influence of HS in these reactions varies with the HS type and concentration. The total organic carbon content (TOC of some commercial HS (such as soil and river humic acid, and fulvic acid was studied. 1-Aminopyrene (1-AP and 1-hydoxypyrene (1-HP are carcinogenic and slightly water-soluble polycyclic aromatic hydrocarbons (PAH. The impact of PAH on natural environment is related to their photolysis rates and photoproducts; therefore, it is of interest to study the photolysis of these compounds. Our previous study showed that the photolysis rate of 1-HP was inhibited by HS. In this study, photolysis of 1-AP was conducted with pure water, natural river water, and pure water containing commercial HS. It was found that the photolysis rate of 1-AP can be inhibited or enhanced by HS, depending on the type and concentration. The first order photolysis rate constant of 1-AP (10 μM in phosphate buffer (pH 7.0, 1 mM containing a humic acid (20-80 ppm was enhanced by up to 5 folds. With a fulvic acid (20-80 ppm, it was enhanced by about 2 folds. With a soil humic acid, it was enhanced by about 2 folds at the concentration of 20 ppm and was inhibited by up to 4 folds at the concentration of 80 ppm. Atrazine (2-chloro-4-ethylamine-6-isopropylamino-s-triazine is a widely used herbicide. It is toxic, often bioaccumulative and persistent. In this study, the effect of HS on the photochemical fate of atrazine was also studied. The results showed that photolysis of atrazine can be enhanced by humic acid, depending on the type and concentration of humic acid. The fulvic acid has no effect on its photolysis within 10 days.

  14. Sequential photochemical and microbial degradation of organic molecules bound to humic acid

    International Nuclear Information System (INIS)

    Amador, J.A.; Zika, R.G.; Alexander, M.

    1989-01-01

    We studied the effects of photochemical processes on the mineralization by soil microorganisms of [2- 14 C]glycine bound to soil humic acid. Microbial mineralization of these complexes in the dark increased inversely with the molecular weight of the complex molecules. Sunlight irradiation of glycine-humic acid complexes resulted in loss of absorbance in the UV range and an increase in the amount of 14 C-labeled low-molecular-weight photoproducts and the rate and extent of mineralization. More than half of the radioactivity in the low-molecular-weight photoproducts appears to be associated with carboxylic acids. Microbial mineralization of the organic carbon increased with solar flux and was proportional to the loss of A 330 . Mineralization was proportional to the percentage of the original complex that was converted to low-molecular-weight photoproducts. Only light at wavelengths below 380 nm had an effect on the molecular weight distribution of the products formed from the glycine-humic acid complexes and on the subsequent microbial mineralization. Our results indicate that photochemical processes generate low-molecular-weight, readily biodegradable molecules from high-molecular-weight complexes of glycine with humic acid

  15. Humic substance-mediated reduction of iron(III) oxides and degradation of 2,4-D by an alkaliphilic bacterium, Corynebacterium humireducens MFC-5

    Science.gov (United States)

    Wu, Chun-yuan; Zhuang, Li; Zhou, Shun-gui; Yuan, Yong; Yuan, Tian; Li, Fang-bai

    2013-01-01

    With the use of an alkaliphilic bacterium, Corynebacterium humireducens MFC-5, this study investigated the reduction of goethite (α-FeOOH) and degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) mediated by different humic substances (humics) and quinones in alkaline conditions (pH of 9.0). The results indicated that (i) using sucrose as the electron donor, the strain MFC-5 was capable of reducing anthraquinone-2,6-disulfonic acid (AQDS), anthraquinone-2-disulfonic acid (AQS), anthraquinone-2-carboxylic acid (AQC), humic acid (HA) and fulvic acid (FA), and its reducing capability ranked as AQC > AQS > AQDS > FA > HA; (ii) the anaerobic reduction of α-FeOOH and 2,4-D by the strain was insignificant, while the reductions were greatly enhanced by the addition of quinones/humics serving as redox mediators; (iii) the Fe(III) reduction rate was positively related to the content of quinone functional groups and the electron-accepting capacities (EAC) of quinones/humics based on fourier-transform infrared spectroscopy (FT-IR) and electrochemical analyses; however, such a relationship was not found in 2,4-D degradation probably because quinone reduction was not the rate-limiting step of quinone-mediated reduction of 2,4-D. Using the example of α-FeOOH and 2,4-D, this study well demonstrated the important role of humics reduction on the Fe(III)/Fe(II) biogeochemical cycle and chlorinated organic compounds degradation in alkaline reducing environments. Funding Information This study was supported by the National Natural Science Foundation of China (Nos 41101211, 31070460, 41101477), and The Project Sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry. PMID:23217085

  16. Hybrid Processes Combining Photocatalysis and Ceramic Membrane Filtration for Degradation of Humic Acids in Saline Water

    Science.gov (United States)

    Song, Lili; Zhu, Bo; Gray, Stephen; Duke, Mikel; Muthukumaran, Shobha

    2016-01-01

    This study explored the combined effects of photocatalysis with ceramic membrane filtration for the removal of humic acid in the presence of salt; to simulate saline wastewater conditions. The effects of operating parameters, such as salinity and TiO2 concentration on permeate fluxes, total organic carbon (TOC), and UV absorbance removal, were investigated. The interaction between the humic acids and TiO2 photocatalyst played an important role in the observed flux change during ceramic membrane filtration. The results for this hybrid system showed that the TOC removal was more than 70% for both without NaCl and with the 500 ppm NaCl concentration, and 62% and 66% for 1000 and 2000 ppm NaCl concentrations. The reduction in UV absorbance was more complete in the absence of NaCl compared to the presence of NaCl. The operation of the integrated photoreactor-ceramic membrane filter over five repeat cycles is described. It can be concluded that the overall removal performance of the hybrid system was influenced by the presence of salts, as salt leads to agglomeration of TiO2 particles by suppressing the stabilising effects of electrostatic repulsion and thereby reduces the effective surface contact between the pollutant and the photocatalyst. PMID:26938568

  17. Hybrid Processes Combining Photocatalysis and Ceramic Membrane Filtration for Degradation of Humic Acids in Saline Water

    Directory of Open Access Journals (Sweden)

    Lili Song

    2016-03-01

    Full Text Available This study explored the combined effects of photocatalysis with ceramic membrane filtration for the removal of humic acid in the presence of salt; to simulate saline wastewater conditions. The effects of operating parameters, such as salinity and TiO2 concentration on permeate fluxes, total organic carbon (TOC, and UV absorbance removal, were investigated. The interaction between the humic acids and TiO2 photocatalyst played an important role in the observed flux change during ceramic membrane filtration. The results for this hybrid system showed that the TOC removal was more than 70% for both without NaCl and with the 500 ppm NaCl concentration, and 62% and 66% for 1000 and 2000 ppm NaCl concentrations. The reduction in UV absorbance was more complete in the absence of NaCl compared to the presence of NaCl. The operation of the integrated photoreactor-ceramic membrane filter over five repeat cycles is described. It can be concluded that the overall removal performance of the hybrid system was influenced by the presence of salts, as salt leads to agglomeration of TiO2 particles by suppressing the stabilising effects of electrostatic repulsion and thereby reduces the effective surface contact between the pollutant and the photocatalyst.

  18. Impact of humic acid on the photoreductive degradation of perfluorooctane sulfonate (PFOS) by UV/Iodide process.

    Science.gov (United States)

    Sun, Zhuyu; Zhang, Chaojie; Chen, Pei; Zhou, Qi; Hoffmann, Michael R

    2017-12-15

    Iodide photolysis under UV illumination affords an effective method to produce hydrated electrons (e aq - ) in aqueous solution. Therefore, UV/Iodide photolysis can be utilized for the reductive degradation of many recalcitrant pollutants. However, the effect of naturally occurring organic matter (NOM) such as humic and fulvic acids (HA/FA), which may impact the efficiency of UV/Iodide photoreduction, is poorly understood. In this study, the UV photoreductive degradation of perfluorooctane sulfonate (PFOS) in the presence of I - and HA is studied. PFOS undergoes a relatively slow direct photoreduction in pure water, a moderate level of degradation via UV/Iodide, but a rapid degradation via UV/Iodide/HA photolysis. After 1.5 h of photolysis, 86.0% of the initial [PFOS] was degraded in the presence of both I - and HA with a corresponding defluorination ratio of 55.6%, whereas only 51.7% of PFOS was degraded with a defluorination ratio of 4.4% via UV/Iodide illumination in the absence of HA. The relative enhancement in the presence of HA in the photodegradation of PFOS can be attributed to several factors: a) HA enhances the effective generation of e aq - due to the reduction of I 2 , HOI, IO 3 - and I 3 - back to I - ; b) certain functional groups of HA (i.e., quinones) enhance the electron transfer efficiency as electron shuttles; c) a weakly-bonded association of I - and PFOS with HA increases the reaction probability; and d) absorption of UV photons by HA itself produces e aq - . The degradation and defluorination efficiency of PFOS by UV/Iodide/HA process is dependent on pH and HA concentration. As pH increases from 7.0 to 10.0, the enhancement effect of HA improves significantly. The optimal HA concentration for the degradation of 0.03 mM PFOS is 1.0 mg L -1 . Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Synergy between surface adsorption and photocatalysis during degradation of humic acid on TiO2/activated carbon composites

    International Nuclear Information System (INIS)

    Xue Gang; Liu Huanhuan; Chen Quanyuan; Hills, Colin; Tyrer, Mark; Innocent, Francis

    2011-01-01

    A photocatalyst comprising nano-sized TiO 2 particles on granular activated carbon (GAC) was prepared by a sol-dipping-gel process. The TiO 2 /GAC composite was characterized by scanning electron microscopy (SEM), X-ray diffractiometry (XRD) and nitrogen sorptometry, and its photocatalytic activity was studied through the degradation of humic acid (HA) in a quartz glass reactor. The factors influencing photocatalysis were investigated and the GAC was found to be an ideal substrate for nano-sized TiO 2 immobilization. A 99.5% removal efficiency for HA from solution was achieved at an initial concentration of 15 mg/L in a period of 3 h. It was found that degradation of HA on the TiO 2 /GAC composite was facilitated by the synergistic relationship between surface adsorption characteristics and photocatalytic potential. The fitting of experimental results with the Langmuir-Hinshelwood (L-H) model showed that the reaction rate constant and the adsorption constant values were 0.1124 mg/(L min) and 0.3402 L/mg. The latter is 1.7 times of the calculated value by fitting the adsorption equilibrium data into the Langmuir equation.

  20. Degradation and structure change of humic acids corresponding to water decline in Zoige peatland, Qinghai-Tibet Plateau

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Xuejun, E-mail: guoxj21@yahoo.com.cn; Du, Wei; Wang, Xuan; Yang, Zhifeng, E-mail: zfyang@bnu.edu.cn

    2013-02-15

    As the largest plateau-type wetland in the world and the largest peat storage in China, Zoige wetland faces severe water decline, and consequently accelerated peat degradation and carbon emission. Here, a variety of characterization approaches, including elemental analysis, UV–vis spectra, FT-IR spectra, and solid state {sup 13}C NMR spectra were used to investigate the degradation and the structural shift of humic acids (HAs) in correspondence with serious water loss in Zoige peatland. Water loss derived from both natural slope and artificial drainage caused a substantial degradation of organic matter and HAs. Compared with the blocks immersed by free surface water, HAs extracted from the drier blocks had more pronounced signals of carboxyl and carbonyl groups, but carried lower content of methoxyl, carbohydrate, alcohol and ether groups. The total aliphatic carbon in HAs from natural-slope drier site decreased almost one half, but in the artificial-drained site, only slightly decreased. Correspondingly, the HA aromaticity substantially increased in the site undergoing the longer time of aerobic oxidation, whereas varied little in the site impacted by extensive water leaching. - Highlights: ► HAs were decomposed significantly due to water loss in Zoige peatland. ► Water loss induced a significant shift in FT-IR and {sup 13}C NMR spectra of HAs. ► The ratio of aliphatic to O-aliphatic carbon (A/O-A ratio) dramatically increased. ► The aromaticity of HAs increased with water loss in the higher-altitude site.

  1. Humic Acid Degradation via Solar Photo-Fenton Process in Aqueous Environment

    Directory of Open Access Journals (Sweden)

    Seyed Ali Sajjadi

    2015-08-01

    Full Text Available Control of mutagenic and carcinogenic disinfection by-products, particularly Trihalomethanes (THMs and Halo Acetic Acids (HAAs in water treatment process is critical, due to their adverse effects on human health. Generally, reducing the toxicity of these by-products hinges on prior removal of the precursor materials, such as Humic Acid (HA in drinking water. This study was conducted to investigate the role of some parameters that could affect the removal of HA, including HA (5 and 10 ppm and H2O2 (20, 40, 60, and 80 ppm initial concentrations, Iron (II, sulfate heptahydrate dosage (4, 8, 12, and 16 ppm, pH (2, 3, 4 and 5, Oxidation time (5, 10, 15 and 30 min, and Sunlight levels (322±13 kWm-2. To accelerate the process of HA removal, the Solar Photo-Fenton (SPF process was employed by direct irradiation of converged sunlight in a Parabolic Trough Collectors (PTC, with 3m2 effective area. HA levels were measured via quantifying Dissolved Organic Carbon (DOC concentrations by means of a TOC Analyzer method. The results showed that the SPF process is under control of the Fe & H2O2 ratio, the Fe2+ dosage and especially the pH quantity. In optimal condition, (pH: 4, oxidation time: 30min, initial HA levels: 50 ppm, H2O2 concentrations: 20 ppm Fe+2 levels: 4 ppm, the study found more than 98% DOC removal. In conclusion, the SPF, as an economically effective technique, could be applied for the removal of HA in aqueous environments.

  2. Potential effects of rainwater-borne H2O2on competitive degradation of herbicides and in the presence of humic acid.

    Science.gov (United States)

    Qin, Junhao; Li, Yongjun; Li, Shengan; Li, Huashou; Lin, Chuxia

    2017-03-01

    In a previous piece of work, we reported some preliminary experimental results showing that hydrogen peroxide at a concentration range frequently encountered in rainwater could lead to degradation of three common herbicides (diuron, butachlor and glyphosate). However, the work was limited to the observation on the effects of Fenton process on the individual herbicides. In field conditions, different types of herbicides along with other organic molecules may occur concurrently. It is unclear how different herbicides and various organic molecules compete for the available hydroxyl radical. In this study, further laboratory experiments were conducted to observe the changes in the herbicides in the scenarios where multiple herbicides or humic acid are present. The results show that humic acid impeded hydroxyl radical-driven degradation of the diuron and butachlor. However, humic acid had no significant effects on reducing glyphosate removal rate. Glyphosate could compete strongly with the humic acid for the available hydroxyl radical in the reaction systems. The reactivity of glyphosate with hydroxyl radical was much higher than those of diuron and butachlor due possibly to its relatively simpler chemical structure, as compared to either diuron or butachlor, which are aromatic compounds that have higher chemical stability. Butachlor degradation was much weaker in the combined diuron and butachlor system than in the combined glyphosate and butachlor system. In the glyphosate-butachlor system, the opposite was observed. The findings have moved another step forward to understanding the potential role of rainwater-borne H 2 O 2 in degrading herbicides in open water environments. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Synthesis, characterization and visible light photocatalytic activity of Cr 3+ , Ce 3+ and N co-doped TiO 2 for the degradation of humic acid

    KAUST Repository

    Rashid, S. G.

    2015-01-01

    The synthesis, characterization and photocatalytic activity of Cr3+ and Ce3+ co-doped TiON (N-doped TiO2) for the degradation of humic acid with exposure to visible light is reported. The synthesized bimetal (Cr3+ + Ce3+) modified TiON (Cr-Ce/TiON), with an evaluated bandgap of 2.1 eV, exhibited an enhanced spectral response in the visible region as compared to pure and Ce3+ doped TiON (Ce/TiON). The XRD analysis revealed the insertion of Cr3+ and Ce3+ in the crystal lattice along with Ti4+ and N that resulted in the formation of a strained TiON anatase structure with an average crystallite size of ∼10 nm. Raman analysis also supported the formation of stressed rigid structures after bimetal doping. HRTEM confirmed the homogeneous distribution of both the doped metallic components in the crystal lattice of TiON without the formation of surface oxides of either Cr3+ or Ce3+. Electron energy loss spectroscopy (EELS) analysis revealed no change in the oxidation of either Cr or Ce during the synthesis. The synthesized Cr-Ce/TiON catalyst exhibited appreciable photocatalytic activity for the degradation of humic acid on exposure to visible light. Additionally, a noticeable mineralization of carbon rich humic acid was also witnessed. The photocatalytic activity of the synthesized catalyst was compared with pristine and Ce3+ doped TiON. © The Royal Society of Chemistry 2015.

  4. Photodegradation of lambda-cyhalothrin and cypermethrin in aqueous solution as affected by humic acid and/or copper: intermediates and degradation pathways.

    Science.gov (United States)

    Xie, Jimin; Wang, Pingli; Liu, Jun; Lv, Xiaomeng; Jiang, Deli; Sun, Cheng

    2011-11-01

    The influence of coexisting humic acids (HA) or Cu²⁺ on the photodegradation of pesticides lambda-cyhalothrin (λ-CHT) and cypermethrin (CPM) in aqueous solution was studied under xenon lamp irradiation. The removal efficiency of pesticides λ-CHT and CPM were enhanced in the presence of either Cu²⁺ or HA but restrained in the presence of both Cu²⁺ and HA. The photodegradation of λ-CHT and CPM followed first-order reaction kinetics. The photodegradation intermediates of λ-CHT and CPM were determined using gas chromatography/mass spectrometry. Possible photodegradation pathways included decarboxylation, ester bond cleavage, dechlorination, and phenyl group removal. Copyright © 2011 SETAC.

  5. DOC removal paradigms in highly humic aquatic ecosystems.

    Science.gov (United States)

    Farjalla, Vinicius F; Amado, André M; Suhett, Albert L; Meirelles-Pereira, Frederico

    2009-07-01

    Dissolved humic substances (HS) usually comprise 50-80% of the dissolved organic carbon (DOC) in aquatic ecosystems. From a trophic and biogeochemical perspective, HS has been considered to be highly refractory and is supposed to accumulate in the water. The upsurge of the microbial loop paradigm and the studies on HS photo-degradation into labile DOC gave rise to the belief that microbial processing of DOC should sustain aquatic food webs in humic waters. However, this has not been extensively supported by the literature, since most HS and their photo-products are often oxidized by microbes through respiration in most nutrient-poor humic waters. Here, we review basic concepts, classical studies, and recent data on bacterial and photo-degradation of DOC, comparing the rates of these processes in highly humic ecosystems and other aquatic ecosystems. We based our review on classical and recent findings from the fields of biogeochemistry and microbial ecology, highlighting some odd results from highly humic Brazilian tropical lagoons, which can reach up to 160 mg C L(-1). Highly humic tropical lagoons showed proportionally lower bacterial production rates and higher bacterial respiration rates (i.e., lower bacterial growth efficiency) than other lakes. Zooplankton showed similar delta(13)C to microalgae but not to humic DOC in these highly humic lagoons. Thus, the data reviewed here do not support the microbial loop as an efficient matter transfer pathway in highly humic ecosystems, where it is supposed to play its major role. In addition, we found that some tropical humic ecosystems presented the highest potential DOC photo-chemical mineralization (PM) rates reported in the literature, exceeding up to threefold the rates reported for temperate humic ecosystems. We propose that these atypically high PM rates are the result of a joint effect of the seasonal dynamics of allochthonous humic DOC input to these ecosystems and the high sunlight incidence throughout the year

  6. Synergistic Removal of Humic Acid in Water by Coupling Adsorption and Photocatalytic Degradation Using TiO2/Coconut Shell Powder Composite

    Directory of Open Access Journals (Sweden)

    Jong Kyu Kim

    2016-01-01

    Full Text Available The feasibility of applying nanoscale TiO2/coconut shell powder (TCNSP composite to remove HA in aqueous solution was evaluated, and the optimization of the photocatalytic systems using newly developed TCNSP composite was performed. The developed TCNSP composite has high specific surface area (i.e., 454 m2/g and great porosity (i.e., 66.9% with pore size of less than 5 μm. High removal efficiencies (≥95% of HA were observed due to the significant synergistic effects by coupling adsorption and photocatalytic reaction of TCNSP composite. As the initial concentration of HA increased, the degradation rate (Kapp decreased due to HA sorption saturation to the surface of TCNSP composite and the photon interception by HA molecules in aqueous solution. Since the increased loading amount of TCNSP composite enhanced the number of active sites, Kapp values increased until the optimum loading amount of TCNSP composite. As pH values increased, HA removal efficiency decreased due to increasing electrostatic repulsion between HA and TCNSP composite. Based on the response surface methodology, higher HA removal efficiencies were obtained with acidic condition, longer reaction time, and appropriated loading amount of TCNSP. Further pilot-scale study is in progress using TCNSP composite combined with UVC to remove HA from large amounts of surface water (i.e., 200 m3/d.

  7. 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...

  8. Estudo da degradação do herbicida ácido 2,4- diclorofenoxiacético (2,4-D por meio da radiação gama do cobalto-60 em solução aquosa contendo ácido húmico Study of degradation of the herbicide 2,4- dichlorophenoxyacetic acid (2,4-d by gamma radiation from cobalto- 60 in aqueous solution containing humic acid

    Directory of Open Access Journals (Sweden)

    Sandro Xavier de Campos

    2002-07-01

    Full Text Available The use of pesticides in agriculture presents some problems to ecosytems as a consequence of their remaining in the environment. Conventional methods for environmental decontamination sometimes just transfer these residues from one place to another. The use of gamma radiation from cobalt-60 to induce 2,4-D degradation in aqueous solution containing humic acid was studied. Results show that the herbicide is completely degraded after treatment with a 30 kGy dose. There were decreases in the degradation of the 2,4-D when humic acid was added at all doses. Some radiolytic products are proposed. The 2,4-D radiolytic yields (G from 2,4-D were calculated.

  9. Humic Substances in waters for supply

    International Nuclear Information System (INIS)

    Camargo Valero, Miller; Cruz Torres, Luis Eduardo

    1999-01-01

    The humic substances make part of the degradation products of the organic matter of the soil and they are incorporate to the superficial waters for the action of laundry that they carry out by the superficial waters. These substances have been recognized as precursors in the formation of the disinfections sub-products, with free chlorine in treatment of drinkable water plants. The disinfections sub-product and the compound organic halogens, they have been classified potentially in human as cancerigenic substances, and therefore the interest in knowing more about the precursors substances, mechanisms of formation of disinfections sub-products, national situation and methods to diminish their formation

  10. Fractal nature of humic materials

    Science.gov (United States)

    Rice, J. A.; Lin, J. S.

    Fractals are geometric representatives of strongly disordered systems whose structure is described by nonintegral dimensions. A fundamental tenet of fractal geometry is that disorder persists at any characterization scale-length used to describe the system. The nonintegral nature of these fractal dimensions is the result of the realization that a disordered system must possess more structural detail than an ordered system with classical dimensions of 1, 2, or 3 in order to accommodate this 'disorder within disorder.' Thus from a fractal perspective, disorder is seen as an inherent characteristic of the system rather than as a perturbative phenomena forced upon it. Humic materials are organic substances that are formed by the profound alteration of organic matter in a natural environment. They can be operationally divided into 3 fractions; humic acid (soluble in base), fulvic acid (soluble in acid or base), and humin (insoluble in acid or base). Each of these fractions has been shown to be an extremely heterogeneous mixture. These mixtures have proven so intractable that they may represent the ultimate in molecular disorder. In fact, based on the characteristics that humic materials must possess in order to perform their functions in natural systems, it has been proposed that the fundamental chemical characteristic of a humic material is not a discrete chemical structure but a pronounced lack of order on a molecular level. If the fundamental chemical characteristic of a humic material is a strongly disordered nature, as has been proposed, then humic materials should be amenable to characterization by fractal geometry. The purpose of this paper is to test this hypothesis.

  11. 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.

  12. Effect of soil invertebrates on the formation of humic substances under laboratory conditions

    Science.gov (United States)

    Frouz, J.; Li, X.; Brune, A.; Pizl, V.; Abakumov, E. V.

    2011-08-01

    The complete polymerization of phenols and proteins (one of the processes involved in the formation of humic substances) was explained. It was shown that fly ( Bibio marci) larvae and earthworms ( Aporrectodea caliginosa) participate in the complete polymerization of phenols and proteins. In a laboratory experiment, invertebrates participated in the degradation of organic matter and the synthesis of humic substances, which was proved in experiments with 14C-labeled phenols and proteins. The same organic substances (phenols and proteins) without the impact of invertebrates were used as the control substances. The distributions of the 14C isotope in alkaline extracts separated by solubility in acids (humic and fulvic acids) was compared to those of the control substances. The portion of the 14C isotope in the humic acids in the excrements of Bibio marci was higher than that in the control substances. The content of 14C-labeled humic substances in the excrements of the earthworm Aporrectodea caliginosa exceeded the control values only in the experiment with proteins. When clay material was added to the organic substances, the portion of the 14C isotope in the humic acids increased in both experiments with phenols and proteins. When these substrates passed through the digestive tracts of the invertebrates, the polymerization of organic substances and the inclusion of proteins and phenols into humic acids occurred.

  13. Humic acid protein complexation

    Science.gov (United States)

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

    2008-04-01

    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 is relatively small and only significant at low and high pH. Next to the proton binding, the mass ratio PAHA/LSZ at the iso-electric point (IEP) of the complex at given solution conditions is measured together with the pH using the Mütek particle charge detector. From the pH changes the charge adaptation due to the interaction can be found. Also these measurements show that the net charge adaptation is weak for PAHA-LSZ complexes at their IEP. PAHA/LSZ mass ratios in the complexes at the IEP are measured at pH 5 and 7. At pH 5 and 50 mmol/L KCl the charge of the complex is compensated for 30-40% by K +; at pH 7, where LSZ has a rather low positive charge, this is 45-55%. At pH 5 and 5 mmol/L KCl the PAHA/LSZ mass ratio at the IEP of the complex depends on the order of addition. When LSZ is added to PAHA about 25% K + is included in the complex, but no K + is incorporated when PAHA is added to LSZ. The flocculation behavior of the complexes is also different. After LSZ addition to PAHA slow precipitation occurs (6-24 h) in the IEP, but after addition of PAHA to LSZ no precipitation can be seen after 12 h. Clearly, PAHA/LSZ complexation and the colloidal stability of PAHA-LSZ aggregates depend on the order of addition. Some implications of the observed behavior are discussed.

  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. 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

  16. 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

  17. The effect of humic acids on biodegradation of polycyclic aromatic hydrocarbons depends on the exposure regime

    International Nuclear Information System (INIS)

    Tejeda-Agredano, Maria-Carmen; Mayer, Philipp; Ortega-Calvo, Jose-Julio

    2014-01-01

    Binding of polycyclic aromatic hydrocarbons (PAHs) to dissolved organic matter (DOM) can reduce the freely dissolved concentration, increase apparent solubility or enhance diffusive mass transfer. To study the effects of DOM on biodegradation, we used phenanthrene and pyrene as model PAHs, soil humic acids as model DOM and a soil Mycobacterium strain as a representative degrader organism. Humic acids enhanced the biodegradation of pyrene when present as solid crystals but not when initially dissolved or provided by partitioning from a polymer. Synchronous fluorescence spectrophotometry, scintillation counting and a microscale diffusion technique were applied in order to determine the kinetics of dissolution and diffusive mass transfer of pyrene. We suggest that humic acids can enhance or inhibit biodegradation as a result of the balance of two opposite effects, namely, solubilization of the chemicals on the one hand and inhibition of cell adhesion to the pollutant source on the other. Highlights: • Humic acids can enhance the biodegradation of PAHs. • The enhancement depends on how the bacteria are exposed to PAHs. • Humic acids stimulate if PAHs are provided by dissolution form crystals. • An inhibition occurs if PAHs are provided by partitioning from a silicone. • The balance between enhanced dissolution and decreased adhesion is the cause. -- Humic acids cause opposite effects on biodegradation of PAHs depending on the exposure regime

  18. 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

  19. Novel humic acid-bonded magnetite nanoparticles for protein immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Bayrakci, Mevlut, E-mail: mevlutbayrakci@gmail.com [Ulukisla Vocational School, Nigde University, 51100 Ulukisla, Nigde (Turkey); Gezici, Orhan [Department of Chemistry, Nigde University, 51100 Nigde (Turkey); Bas, Salih Zeki; Ozmen, Mustafa; Maltas, Esra [Department of Chemistry, Selcuk University, 42031 Konya (Turkey)

    2014-09-01

    The present paper is the first report that introduces (i) a useful methodology for chemical immobilization of humic acid (HA) to aminopropyltriethoxysilane-functionalized magnetite iron oxide nanoparticles (APS-MNPs) and (ii) human serum albumin (HSA) binding to the obtained material (HA-APS-MNPs). The newly prepared magnetite nanoparticle was characterized by using Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and elemental analysis. Results indicated that surface modification of the bare magnetite nanoparticles (MNPs) with aminopropyltriethoxysilane (APS) and HA was successfully performed. The protein binding studies that were evaluated in batch mode exhibited that HA-APS-MNPs could be efficiently used as a substrate for the binding of HSA from aqueous solutions. Usually, recovery values higher than 90% were found to be feasible by HA-APS-MNPs, while that value was around 2% and 70% in the cases of MNPs and APS-MNPs, respectively. Hence, the capacity of MNPs was found to be significantly improved by immobilization of HA. Furthermore, thermal degradation of HA-APS-MNPs and HSA bonded HA-APS-MNPs was evaluated in terms of the Horowitz–Metzger equation in order to determine kinetic parameters for thermal decomposition. Activation energies calculated for HA-APS-MNPs (20.74 kJ mol{sup −1}) and HSA bonded HA-APS-MNPs (33.42 kJ mol{sup −1}) implied chemical immobilization of HA to APS-MNPs, and tight interactions between HA and HA-APS-MNPs. - Highlights: • A new magnetite nanoparticle based humic acid was prepared for the first time. • Protein binding studies of magnetite nanoparticle based humic acid were performed. • Kinetic parameters of protein and/or humic acid bonded nanoparticles were evaluated.

  20. 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 sh...

  1. A comprehensive structural evaluation of humic substances using several fluorescence techniques before and after ozonation. Part II: evaluation of structural changes following ozonation.

    Science.gov (United States)

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

    2014-04-01

    The main objective of this work (Part II) is to evaluate the usefulness of fluorescence techniques to monitor structural changes in humic substances produced by the ozonation treatment, using all the current fluorescence techniques: Emission scan fluorescence (ESF), synchronous fluorescence spectroscopy (SFS), total luminescence spectroscopy (TLS or EEM) through the use of both 2-D contour maps and 3-D plots, fluorescence index and the λ0.5 parameter. Four humic substances were studied in this work: three of them were provided by the International Humic Substances Society (Suwannee River Fulvic Acid Standard: SUFA, Suwannee River Humic Acid Standard: SUHA and Nordic Reservoir Fulvic Acid Reference: NOFA) and the other one was a commercial humic acid widely used as a surrogate for aquatic humic substances in various studies (Aldrich Humic Acid: ALHA). The lowest ozone dosage tested (0.25mg O3/mg TOC) caused no appreciable change in the different types of fluorescence spectra under study, therefore the structural change produced in the humic macromolecules may be considered of little significance. Concerning EEM and synchronous spectra, the two natural fulvic acids (SUFA and NOFA) showed a decrease in fluorescence intensity as ozone dosage increased, but the natural humic acid (SUHA) showed a different behaviour: an initial increase in fluorescence intensity at medium ozone dosages (1.5 mg O3/mg TOC) followed by an intensity decrease for the higher ozone dose (7.5 mg O3/mg TOC). Regarding synchronous spectra, the moderate dosage of 1.5 mg O3/mg TOC led to an increase in the fluorescence of the protein-like peak at λsyn=285 nm for the natural humic substances. The results obtained for the fluorescence index and λ0.5 may suggest that the greatest degradation of aromatic structures within the humic macromolecule occurs at high ozone dosages, whereas the predominant effect at moderate dosages would be the break-up of the humic macromolecule into lower molecular weight

  2. Biodegradation of dissolved humic substances by fungi.

    Science.gov (United States)

    Collado, Sergio; Oulego, Paula; Suárez-Iglesias, Octavio; Díaz, Mario

    2018-04-01

    Humic and fulvic acids constitute humic substances, a complex mixture of many different acids containing carboxyl and phenolate groups, which are not only the principal soil fertility factors but also the main pollutants present in landfill leachates or natural organic matter in water. Due to their low bacterial biodegradability, fungal biodegradation processes are key for their removal. The present study compiles and comments all the available literature on decomposition of aqueous humic substances by fungi or by their extracellular enzymes alone, focusing on the influence of the reaction conditions. The biodegradation extent mainly depends on the characteristics and concentration of the humic compounds, the type of microorganisms selected, the inoculation mode, the C and N sources, the presence of certain chemicals in the medium, the availability of oxygen, the temperature, and the pH.

  3. 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.

  4. Effects of humic substances on the migration of radionuclides: Complexation of actinides with humic substances

    International Nuclear Information System (INIS)

    Kim, J.I.; Rhee, D.S.; Wimmer, H.; Buckau, G.; Klenze, R.; Decambox, P.; Moulin, C.; Moulin, V.; Tits, J.; Marquardt, C.; Herrmann, G.; Trautmann, N.; Dierckx, A.; Vancluysen, J.; Maes, A.

    1992-09-01

    The aim of the present research programme is to study the complexation behaviour of actinide ions with humic substances in natural aquifer systems and hence to quantify the effect of humic substances on the actinide migration. Aquatic humic substances commonly found in all groundwaters in different concentrations have a strong tendency towards complexation with actinide ions. This is one of the major geochemical reactions but hitherto least quantified. Therefore, the effect of humic substances on the actinide migration is poorly understood. In the present research programme the complexation of actinide ions with humic substances will be described thermodynamically. This description will be based on a model being as simple as possible to allow an easy introduction of the resulting constants into geochemical modelling of the actinide migration. (orig.)

  5. Effects of humic substances on the migration of radionuclides: complexation of actinides with humic substances

    International Nuclear Information System (INIS)

    Kim, J.I.; Buckau, G.

    1993-01-01

    The aim of the present research programme is to study the complexation behaviour of actinide ions with humic substances in natural aquifer systems and hence to quantify the effect of humic substances on the actinide migration. Aquatic humic substances commonly found in all groundwaters in different concentrations have a strong tendency towards complexation with actinide ions. This is one of the major geochemical reactions but hitherto least quantified. Therefore, the effect of humic substances on the actinide migration is poorly understood. In the present research programme the complexation of actinide ions with humic substances will be described thermodynamically. This description will be based on a model being as simple as possible to allow an easy introduction of the resulting constants into geochemical modelling of the actinide migration. 13 refs

  6. Structure-reactivity relationships in the interactions between humic substances, pollutants from the nuclear cycle, and mineral surfaces

    International Nuclear Information System (INIS)

    Reiller, Pascal

    2015-01-01

    This document proposes an analysis of the structure-reactivity relationships in the interaction between humic substances, metallic pollutants from the nuclear cycle, and mineral surfaces. It composes the scientific document, which allowed the author to defend a Habilitation degree. It is mainly focused on the research works into which the author have been involved in on this particular thematic. Humic substances are issued from the degradation of the living. They have an important influence onto migration of metals in the environment. They are showing particular intrinsic physic and chemical, metal complexation, and adsorption onto mineral surfaces properties, which render the global comprehension of the different mechanisms somehow difficult. These three aspects are covered in this document. The first part is dedicated to the studies on composition, structure, and organization of humic substances, which cannot be considered as a well-defined type of chemical. They are a heterogeneous degradation product with a supramolecular organization, which is showing fractal properties from fractions up to several nanometers. Second part is on the complexation reactions. The different modelling strategies come from the difficulties on apprehending composition, structure, and organization of humic substances. The different models used are showing more or less strongly empiric characteristics. They can be derived from the mass action law, or explicitly account for heterogeneity, acid-basic, or ionic strength related parameters. The third and latter part covers the adsorption studies. The main property is adsorptive fractionation, which induces modification of chemical composition of humic substances between the surface and the solution. It also induces modification of complexation properties between the adsorbed and non-adsorbed fractions. Because of adsorptive fractionation, and the particular influence of ionic strength on humic substances, and of complexed metals, adsorption

  7. 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...

  8. Humic substances-mediated microbial reductive dehalogenation of triclosan

    Science.gov (United States)

    Wang, L.; Xu, S.; Yang, Y.

    2015-12-01

    The role of natural organic matter in regulating the redox reactions as an electron shuttle has received lots of attention, because it can significantly affect the environmental degradation of contaminants and biogeochemical cycles of major elements. However, up to date, limited studies examined the role of natural organic matter in affecting the microbial dehalogenation of emergent organohalides, a critical detoxification process. In this study, we investigated the humic substance (HS)-mediated microbial dehalogenation of triclosan, a widely used antimicrobial agent. We found that the presence of HS stimulated the microbial degradation of triclosan by Shewanella putrefaciens CN-32. In the absence of HS, the triclosan was degraded gradually, achieving 8.6% residual at 8 days. With HS, the residual triclosan was below 2% after 4 days. Cl- was confirmed by ion chromatography analysis, but the dehalogenation processes and other byproducts warrant further investigations. The impact of HS on the degradation of triclosan was highly dependent on the concentration of HS. When the HS was below 15 mg/L, the degradation rate constant for triclosan increased with the organic carbon concentration. Beyond that point, the increased organic carbon concentration decreased the degradation of triclosan. Microbially pre-reduced HS abiotically reduced triclosan, testifying the electron shuttling processes. These results indicate that dissolved organic matter plays a dual role in regulating the degradation of triclosan: it mediates electron transport and inhibits the bioavailability through complexation. Such novel organic matter-mediated reactions for organohalides are important for evaluating the natural attenuation of emergent contaminants and designing cost-effective engineering treatment.

  9. 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.

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

    African Journals Online (AJOL)

    FEA

    2014-02-24

    Feb 24, 2014 ... 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.

  11. Role of loosely bound humic substances and humin in the bioavailability of phenanthrene aged in soil.

    Science.gov (United States)

    Nam, K; Kim, J Y

    2002-01-01

    A study was conducted to determine a possible role of loosely bound humic substances (i.e., humic and fulvic acids) in bioavailability of aged phenanthrene with time. In this study, long-term residence of phenanthrene in soil is defined as aging or sequestration, and the effect was determined by the declined bioavailability to bacteria of the polycyclic aromatic hydrocarbon with increased residence time. After 1, 7, and 100 days of aging of phenanthrene in Lima loam, about 90-93% of initial phenanthrene was recovered from the humin-mineral fraction of Lima loam whereas less than 12% was found in humic and fulvic acids of the same soil. Mineralization rates of phenanthrene aged in the humin-mineral fraction significantly decreased with time by the test bacterium P5-2. In terms of extents of mineralization, the difference with time was not appreciable, but still significant at Phumin-mineral fraction, and probably humic and fulvic acids may act as a physico-chemical barrier to bacterial degradation so that the compound's bioavailability may be limited.

  12. Structure and dynamics of humic substances and model poly-electrolytes in solution

    International Nuclear Information System (INIS)

    Roger, G.

    2010-09-01

    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)

  13. Radiocarbon ages of humic substances in chernozems

    Science.gov (United States)

    Ivanov, I. V.; Khokhlova, O. S.

    2008-12-01

    Data on radiocarbon ages of different fractions of humus (humic acids, fulvic acids, and humin) in the profiles of chernozems are analyzed. A chronoecological grouping of humus in modern and buried (fossil) soils is suggested. An increase in the radiocarbon age of humic substances down the soil profile has a stepwise character. It is shown that the 14C content in chernozems decreases down the soil profile more somewhat slower than the 12C content. The dependence of a decrease in the humus content of buried soils on the age of burying is traced for a time span of 800 ka.

  14. 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...

  15. 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...

  16. 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

  17. 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. The less humified samples contain relatively more components having a relationship to lignin. The more humified samples are composed of relatively more molecular formulas in the CCAM and condensed aromatic regions and also contain relatively more carboxylated molecular formulas than the less humified samples. To explain the molecular formulas observed we propose a humification process that involves photo- or microbially-generated reactive oxygen species in soils which are responsible for transforming the materials supplied to soil as fresh organic matter, mainly lignin, to the molecules observed in ESI-FTICR-MS data. When plotted on the van Krevelen diagram, the H/C and O/C ratios of molecular formulas from humic acids predictably plot in the same regions as the newly produced formulas discovered by Chen, et al. (2014) when natural organic matter was photoirradiated or when lignin-derived humics were subjected to Fenton chemistry (Waggoner et al., 2015). References: Chen H., Abdulla H.A.N., Sanders R.L., Myneni S.C.B., Mopper K. and Hatcher P.G. (2014) Production of Black Carbon-like and Aliphatic Molecules from Terrestrial Dissolved Organic Matter in the Presence of Sunlight and Iron. Environmental Science & Technology Letters 1, 399-404. Waggoner D.C., Chen H., Willoughby A.S. and Hatcher P.G. (2015) Formation of black carbon-like and alicyclic aliphatic compounds by hydroxyl radical initiated degradation of lignin. Organic Geochemistry 82, 69-76.

  18. Binding of cationic surfactants to humic substances

    NARCIS (Netherlands)

    Ishiguro, M.; Tan, W.; Koopal, L.K.

    2007-01-01

    Commercial surfactants are introduced into the environment either through waste products or site-specific contamination. The amphiphilic nature of both surfactants and humic substances (HS) leads to their mutual attraction especially when surfactant and HS are oppositely charged. Binding of the

  19. Chromatography of humic substances on controlled pore glass

    International Nuclear Information System (INIS)

    Danneberg, O.H.

    1977-01-01

    To check the suitability of controlled pore glass (CPG) for the chromatography of humic substances, a soil extract from an Austrian chernozem and humic fractions prepared from the extract were chromatographed using a column filled with CPG of a pore diameter of 156A. The chromatograms obtained were reproducible, and showed the expected sequence of elution, grey humic acids (GHA) being eluted before brown humic acids (BHA) and fulvic acids (FA). Chromatograms of complex humic systems agreed well with the computed sums of the chromatograms of all its components. This means that all humic substances moved through the column independently of the presence or absence of others. From these findings, the suitability of CPG for chromatography of humic substances was concluded. A structural alteration of GHA during the preparation was detected. This was accompanied by a decrease in molecular weight and an increase in colour intensity. (author)

  20. [FTIR Spectroscopic Analysis of Humic-Like Substances Extracted from the Microbial Residues].

    Science.gov (United States)

    Wang, Shuai; Dou, Sen; Zhang, Xi; Cui, Yan-jie; Wang, Ting

    2015-12-01

    Drived by the soil microorganisms, the decomposition and transformation of cellulose plays an important role in the formation of humic substances. The techniques of infrared spectrum combining with element analysis were adopted to compare the structural differences of humic-like substances (HLA, humic-like acid; Hu, humin) extracted from the microbial residues formed in the liquid shake-flask culture (70 days), in which the single fungi (Trichoderma viride, Penicillium and Aspergillus niger) and mixed strains participated. The results showed that: (1) The combination of two techniques could clarify the molecu- lar structure of HLA extracted from the microbial residues, however, it remained to be further discussed in terms of analyzing the structures of Hu; (2) Trichoderma viride was beneficial to the condensation of HLA extracted from its microbial residue, but Penicillium was more favorable to the degradation of HLA. (3) The oxidative degradation of HLA fractions extracted the microbial residues was implemented by Penicillium and mixed strains. Both of the mixed strains and Aspergillus niger were helpful to transfer the inorganic N compounds from the culture media into the organic N components of HLA and Hu extracted from the microbial residues, simultaneously increase their amino C contents and then provide the indispensable N source for the humification process.

  1. Genome sequence of the button mushroom Agaricus bisporus reveals mechanisms governing adaptation to a humic-rich ecological niche

    Energy Technology Data Exchange (ETDEWEB)

    Morin, Emmanuelle; Kohler, Annegret; Baker, Adam R.; Foulongne-Oriol, Marie; Lombard, Vincent; Nagy, Laszlo G.; Ohm, Robin A.; Patyshakuliyeva, Aleksandrina; Brun, Annick; Aerts, Andrea L.; Bailey, Andrew M.; Billette, Christophe; Coutinho, Pedro M.; Deakin, Greg; Doddapaneni, Harshavardhan; Floudas, Dimitrios; Grimwood, Jane; Hilden, Kristiina; Kues, Ursula; LaButti, Kurt M.; Lapidus, Alla; Lindquist, Erika A.; Lucas, Susan M.; Murat, Claude; Riley, Robert W.; Salamov, Asaf A.; Schmutz, Jeremy; Subramanian, Venkataramanan; Wosten, Han A. B.; Xu, Jianping; Eastwood, Daniel C.; Foster, Gary D.; Sonnenberg, Anton S. M.; Cullen, Dan; de Vries, Ronald P.; Lundell, Taina; Hibbett, David S.; Henrissat, Bernard; Burton, Kerry S.; Kerrigan, Richard W.; Challen, Michael P.; Grigoriev, Igor V.; Martin, Francis

    2012-04-27

    Agaricus bisporus is the model fungus for the adaptation, persistence, and growth in the humic-rich leaf-litter environment. Aside from its ecological role, A. bisporus has been an important component of the human diet for over 200 y and worldwide cultivation of the button mushroom forms a multibillion dollar industry. We present two A. bisporus genomes, their gene repertoires and transcript profiles on compost and during mushroom formation. The genomes encode a full repertoire of polysaccharide-degrading enzymes similar to that of wood-decayers. Comparative transcriptomics of mycelium grown on defined medium, casing-soil, and compost revealed genes encoding enzymes involved in xylan, cellulose, pectin, and protein degradation are more highly expressed in compost. The striking expansion of heme-thiolate peroxidases and etherases is distinctive from Agaricomycotina wood-decayers and suggests a broad attack on decaying lignin and related metabolites found in humic acid-rich environment. Similarly, up-regulation of these genes together with a lignolytic manganese peroxidase, multiple copper radical oxidases, and cytochrome P450s is consistent with challenges posed by complex humic-rich substrates. The gene repertoire and expression of hydrolytic enzymes in A. bisporus is substantially different from the taxonomically related ectomycorrhizal symbiont Laccaria bicolor. A common promoter motif was also identified in genes very highly expressed in humic-rich substrates. These observations reveal genetic and enzymatic mechanisms governing adaptation to the humic-rich ecological niche formed during plant degradation, further defining the critical role such fungi contribute to soil structure and carbon sequestration in terrestrial ecosystems. Genome sequence will expedite mushroom breeding for improved agronomic characteristics.

  2. Contribution of bacterial cell nitrogen to soil humic fractions

    International Nuclear Information System (INIS)

    Knowles, R.; Barro, L.

    1981-01-01

    Living cells of Serratia marcescens, uniformly labelled with 15 N, were added to samples of maple (Acer saccharum) and black spruce (Picea mariana) forest soils. After different periods of incubation from zero time to 100 days, the soils were subjected to alkali-acid and phenol extraction to provide humic acid, fulvic acid, humin and 'humoprotein' fractions. Significant amounts of the cell nitrogen were recovered in the humic and fulvic acids immediately after addition. After incubation, less cell nitrogen appeared in the humic acid and more in the fulvic acid. The amount of cell nitrogen recovered in the humin fraction increased with incubation. Roughly 5 to 10 per cent of the added cell nitrogen was found as amino acid nitrogen from humoprotein in a phenol extract of the humic acid. The data are consistent with the occurrence of co-precipitation of biologically labile biomass nitrogen compounds with humic polymers during the alkaline extraction procedure involved in the humic-fulvic fractionation. (orig.)

  3. Characterization of reference and site specific humic acids

    International Nuclear Information System (INIS)

    Kim, J.I.; Buckau, G.

    1988-11-01

    As a contribution to the interlaboratory exercise for the complexation of humic acid and colloid generation (COCO-Club activities) in the CEC project MIRAGE-II, the characterization of selected humic acids have been carried out at TU Muenchen, regarding their elemental compositions, inorganic impurities, spectroscopic properties, size distributions and proton exchange capacities. The commercial humic acid (Na salt) from Aldrich Co. is purified to a protonated form and used as reference material. Furthermore two humic acids extracted from groundwaters from Gorleben (FRG) and Boom Clay (B) are purified to protonated forms and taken as site specific materials. These three humic acids, together with the original Na salt from Aldrich Co., are included in the present characterization exercise. The results of characterization provide basic knowledge supporting the forthcoming study of complexation of actinides and fission products with humic acid and their migration processes in the geosphere. (orig.)

  4. Effect of Humic Acids and pesticides on Agricultural Soil Structure and Stability and Its Implication on Soil Quality

    Science.gov (United States)

    Gaonkar, O. D.; Nambi, I. M.; G, S. K.

    2016-12-01

    The functional and morphological aspects of soil structure determine the soil quality. The dispersion of colloidal soil particles, especially the clay fraction and rupture of soil aggregates, both of which play an important role in soil structure development, lead to degradation of soil quality. The main objective of this work was to determine the effect of behaviour of soil colloids on the agricultural soil structure and quality. The effect of commercial humic acid, organophosphate pesticides and soil natural organic matter on the electrical and structural properties of the soil colloids was also studied. Agricultural soil, belonging to the sandy loam texture class from northern part of India was considered in this study. In order to understand the changes in the soil quality in the presence and absence of humic acids, the soil fabric and structure was analyzed by X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) Spectroscopy and Scanning Electron Microscopy (SEM). Electrical properties of natural soil colloids in aqueous suspensions were assessed by zeta potential measurements at varying pH values with and without the presence of humic acids and pesticides. The influence of natural organic matter was analyzed by oxidizing the natural soil organic matter with hydrogen peroxide. The zeta potential of the soil colloids was found to be negative in the pH range studied. The results indicated that hydrogen peroxide treatment lead to deflocculation of colloidal soil particles. In addition, the humic acids undergoes effective adsorption onto the soil surface imparting more negative zeta potential to the colloidal soil particles. The soil hydrophilicity decreased in the presence of humic acids which was confirmed by surface free energy determination. Thus, it can be concluded that the presence of humic acids altered the soil fabric and structure, thereby affecting the soil quality. This study assumes significance in understanding the soil aggregation and the

  5. Influence of vermicompost humic acid on chlorophyll content and ...

    African Journals Online (AJOL)

    S

    2016-11-23

    Nov 23, 2016 ... cattle used was fed mainly with grasses, and the manure was processed with African red worm. This vermicompost was used for the humic substances extraction according to International humic substances society (2008) with NaOH (0.1 mol L-1) in a proportion of 1:10 (mg of vermicompost: mL dissolution) ...

  6. Stability constant of the lanthanum complex with humic acid

    International Nuclear Information System (INIS)

    Jimenez R, M.; Solache R, M. J.

    2008-01-01

    The work described here is a study on the formation of trivalent lanthanum complex with humic acid. Commercial humic acid was purified and then characterized by various analytical techniques. The stability constant determined by a radiochemical method has a worth of log β La , AHA = 13.6. (Author)

  7. 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 ...

  8. 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

  9. 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.

  10. 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...

  11. Humic products in agriculture: Potential benefits and research challenges

    Science.gov (United States)

    Humic products have been used in cropland agriculture for several decades, but lack of widespread credibility has restricted their use to small proportions of farmers. To improve the credibility of humic products, we identify four knowledge gaps and propose pathways of future action to close these g...

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

    African Journals Online (AJOL)

    The mobility of a pesticide in soil is determined by the extent and strength of sorption, which is influenced by either the existing soil humus or exogenous humic substances. Exogenous humic acids (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 ...

  13. 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 ...

  14. 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.

  15. Effects of humic substances on the migration of radionuclides: Complexation of actinides with humic substances. 1. progress report

    International Nuclear Information System (INIS)

    Kim, J.I.; Buckau, G.; Klenze, R.; Rhee, D.S.; Wimmer, H.; Decambox, P.; Mauchien, P.; Moulin, C.; Moulin, V.; Tits, J.; Marquardt, C.; Riegel, J.; Sattelberger, P.; Herrmann, G.; Trautmann, N.; Diercks, A.; Vancluysen, J.; Maes, A.; Bidoglio, G.; Righetto, L.

    1992-02-01

    The aim of the present research programme is to study the complexation behaviour of actinide ions with humic substances in natural aquifer systems and hence to quantify the effect of humic substances on the actinide migration. Aquatic humic substances commonly found in all groundwaters in different concentrations have a strong tendency towards complexation with actinide ions. This is one of the major geochemical reactions but hitherto least quantified. Therefore, the effect of humic substances on the actinide migration is poorly understood. In the present research programme the complexation of actinide ions with humic substances will be described thermodynamically. This description will be based on a model being as simple as possible to allow an easy introduction of the resulting constants into geochemical modelling of the actinide migration. This programme is a continuation of the activities of the COCO group in the second phase of the CEC-MIRAGE project. (orig.)

  16. Effect of the use and the cover of the soil on the profile of polydispersity of humic acids extracted of an andisol from the department of Caldas, Colombia

    International Nuclear Information System (INIS)

    Avellaneda, Lizeth Manuela; Lozano de Yunda, Amanda; Zamudio, Adriana Mireya

    2005-01-01

    In order to know the possible effect of the use and the cover of soil, on the polydispersity profile of humic acids were analyzed the a horizon of three samples of an andisol (melanudand) from the department of Caldas, Colombia, that have presented different management and coverland as soils under forest of bamboo, coffee with somber of Guamo and under free exposition coffee. For this in the lower fraction to 50 μm, the sequential extraction of humic substances was carried out with solutions of sodium tetraborate (Na2B 4 O7 0.05 m), sodium pyrophosphate (Na4P 2 O7 0.025 m) and sodium hydroxide (NaOH 0.1m) and the later separation and purification of the respective humic acids. To obtain the polydispersity profiles were applied the exclusion chromatography separation by size technique utilizing sephadex g-75 and ultra centrifugation by gradient of density with sucrose and they devised graphics of distribution by size (absorbance (450 nm) vs. volume eluted). It was found that the humic acids extracted with sodium hydroxide presented smaller polydispersity, bigger size and molecular weight, as well as, degree of aromatic condensation. The results did not show drastic effect of the use and the cover land, on the polydispersity profile and the coefficient of sedimentation of the humic acids, which is related to the size, weight and molecular density of the same ones. Nevertheless, it was found that the humic acids of the samples of soil under coffee with somber of Guamo and free exposition coffee are very similar among it and different from the sample under forest of bamboo. This fact was associated with a beginning of the effect of the use and the cover of the soil on the size of the humic acids. It presumed that in the long term the effect is accentuated and eventually could be considered as indicator of degradation of the organic component of the soil

  17. Interaction of neptunium with humic acid and anaerobic bacteria

    International Nuclear Information System (INIS)

    Kubota, Takumi; Sasaki, Takayuki; Kudo, Akira

    2002-01-01

    Humic acid and bacteria play an important role in the migration of radionuclides in groundwaters. The interaction of neptunium with humic acid and anaerobic bacteria has been investigated by liquid/liquid and solid/liquid extraction systems. For liquid/liquid extraction, the apparent complex formation constant, β α was obtained from the distribution between two phases of neptunium. For solid/liquid extraction, the ratio of sorption to bacteria, K d , was measured. K d of humic acid can be evaluated from β α . The large value of β α and K d means strong interaction of neptunium with organisms. In order to examine the effect of the nature of organism on interaction, the interaction with humic acid was compared to that with non-sterilized or sterilized mixed anaerobic bacteria. The value of β α of humate depended on neptunium ion concentration as well as pH, which showed the effect of polyelectrolyte properties and heterogeneous composition of humic acid. The comparison of interaction with humic acid and bacteria indicated that the K d value of humic acid was larger than that of bacteria and more strongly depend on pH. (author)

  18. Neptunium speciation in humic acid - goethite system

    International Nuclear Information System (INIS)

    Kalmykov, St.; Khasanova, A.; Shcherbina, N.; Perminova, I.; Schafer, T.; Claret, F.; Teterin, Y.

    2007-01-01

    Full text of publication follows. Humic acids (HA) are known to have significant effect on metal ion speciation in the environment and may either enhance or depress their migration ability depending on geochemical conditions. This study deals with Np(V) behaviour in HA-goethite suspension at different pH values. The HA used in this study were enriched in hydroquinone group content that define their redox properties. The sorption of Np(V) by goethite in the presence of HA was studied in batch mode at pHs from 2.5 to 9. It was established that at low pH values the sorption of Np agrees with the sorption of HA by goethite and was significantly higher than in binary Np-goethite system. The scanning transmission X-ray microscopic (STXM) study done at National Synchrotron Light Source (BNL, USA) was used to characterize humic surface coatings on goethite. According to STXM, organic matter 'hot spots' were observed in the central region of goethite particles. These 'hot spots' revealed high amounts of C=C arom and aliphatic structures, whereas edge regions of goethite particles or the cloudy regions around this particle contained lower amounts of these organic functionalities. The particle edge structures and the surrounding of the particle were enriched in oxygen-containing functional groups. The enhanced Np sorption at low pH values was explained by its reduction to tetravalent state with formation of stable Np(IV) humates that was established by Vis-NIR spectrophotometry for binary Np(V)-HA solutions and XPS for ternary Np-HA-goethite system. At pH > 6 neptunium retention by HA-goethite suspension was slightly lower that in the absence of HA that is due to week Np(V) humic complexation in solution. According to STXM no detection of organics on goethite minerals by carbon K-edge measurements was possible and the results might be interpreted as an absence of organic matter sorption on the mineral phases under the conditions of batch-type studies. The absence of Np

  19. Characterisation of humic material for inter-laboratory comparison

    International Nuclear Information System (INIS)

    Peachy, D.; Bradley, A.D.; Davis, A.E.; Stuart, M.E.; Tait, B.A.R.; Vickers, B.P.; Williams, G.M.

    1988-01-01

    The characterisation and interlaboratory comparison of common humic materials by members of the European Commission's COCO group (set up to study complexes and colloids), forms part of a study of the effects of natural organic compounds in groundwater on the complexation and mobility of radionuclides. Three samples have been characterised: a sodium salt and a protonated form of the commercially available humic acid from Aldrich Chemicals; and a protonated humic acid from the Gorleben research site in Germany. Characterisation undertaken by BGS includes moisture content, elemental analysis, metal content, functional group analysis, infra-red spectroscopy, ultra-violet absorbance (E 4 /E 6 ratios), and ultra-filtration. (author)

  20. 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.

  1. Removal of 17β-estradiol in a Biological Active Carbon Reactor with Acetic Acid and Humic Acid.

    Science.gov (United States)

    Li, Zhongtian; Stenstrom, Michael K; Li, Xu

    2017-09-01

      The objective of this study is to characterize the removal of 17β-estradiol (E2) and the microbial community of a biologically active carbon (BAC) reactor under acetic acid or humic acid as the primary carbon source. Influent E2 concentration was maintained at 20 μg/L. Higher than 99% removal of E2 was achieved by the BAC reactor. The concentration of E2 increased from below detection limit (carbon source from acetic acid to humic acid in the reactor influent. Meanwhile, effluent estrone concentration increased from 50 ± 15 to 55 ± 15 ng/L after the switch of primary carbon source in the reactor influent. 17β-estradiol degrading bacteria were isolated. Microbial community structures under different nutrient conditions were revealed by high throughput sequencing. The presence of readily biodegradable carbon source such as acetic acid benefited E2 removal in the BAC reactor.

  2. Adsorption of humic acids and trace metals in natural waters

    Science.gov (United States)

    Leung, W. H.

    1982-01-01

    Studies concerning the interactions between suspended hydrous iron oxide and dissolved humic acids and trace metals are reported. As a major component of dissolved organic matters and its readiness for adsorption at the solid/water interface, humic acids may play a very important role in the organometallic geochemistry of suspended sediments and in determining the fate and distribution of trace metals, pesticides and anions in natural water systems. Most of the solid phases in natural waters contain oxides and hydroxides. The most simple promising theory to describe the interactions of hydrous iron oxide interface is the surface complex formation model. In this model, the adsorptions of humic acids on hydrous iron oxide may be interpreted as complex formation of the organic bases (humic acid oxyanions) with surface Fe ions. Measurements on adsorptions were made in both fresh water and seawater. Attempts have been made to fit our data to Langmuir adsorption isotherm. Adsorption equilibrium constants were determined.

  3. Characterization and complexation of humic acids. Part 1

    International Nuclear Information System (INIS)

    Kim, J.L.; Buckau, G.; Klenze, R.; Rhee, D.S.; Wimmer, H.

    1991-01-01

    This paper summarizes the research contributions to the CEC Mirage II project, particularly the research area on complexation and colloids (COCO). The first part of the paper comprises the characterization of humic and fulvic acids from different origins: a commercial product from the Aldrich Co. used as a reference humic acid and site-specific humic acids from Gorleben (Germany), Boom Clay (Belgium) and Fanay Augeres (France) aquifer systems. The second part includes the complexation of trivalent actinides: Am(III) and Cm(III) with various humic acids. A number of different methods have been applied for the complexation study: spectrophotometry, ultrafiltration, laser-induced photo-acoustic spectroscopy (LPAS) and time-resolved laser fluorescence spectroscopy (TRLFS). The evaluation process of complexation constant is discussed extensively and the well consolidated results are presented, which can be directly used for the geochemical modelling of the radionuclide migration

  4. 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.

    in Thin film) that these natural complexing agents do enter the gel layer, and that humic acids even appear to accumulate in the gel, with enrichment factors typicallyonthe order of 10. The results have consequences for the interpretation of DGT...

  5. Humic colloid-borne migration of uranium in sand columns

    International Nuclear Information System (INIS)

    Artinger, R.; Rabung, T.; Kim, J.I.; Sachs, S.; Schmeide, K.; Heise, K.H.; Bernhard, G.; Nitsche, H.

    2002-09-01

    Column experiments were carried out to investigate the influence of humic colloids on subsurface uranium migration. The columns were packed with well-characterized aeolian quartz sand and equilibrated with groundwater rich in humic colloids (dissolved organic carbon (DOC): 30 mg dm -3 ). U migration was studied under an Ar/1% CO 2 gas atmosphere as a function of the migration time, which was controlled by the flow velocity or the column length. In addition, the contact time of U with groundwater prior to introduction into a column was varied. U(VI) was found to be the dominant oxidation state in the spiked groundwater. The breakthrough curves indicate that U was transported as a humic colloid-borne species with a velocity up to 5% faster than the mean groundwater flow. The fraction of humic colloid-borne species increases with increasing prior contact time and also with decreasing migration time. The migration behavior was attributed to a kinetically controlled association/dissociation of U onto and from humic colloids and also a subsequent sorption of U onto the sediment surface. The column experiments provide an insight into humic colloid-mediated U migration in subsurface aquifers

  6. Fixation and transport of uranium by humic substances (1962)

    International Nuclear Information System (INIS)

    Martin, J.

    1962-03-01

    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) [fr

  7. Binding of ciprofloxacin by humic substances: a molecular dynamics study.

    Science.gov (United States)

    Aristilde, Ludmilla; Sposito, Garrison

    2010-01-01

    A comprehensive assessment of the potential impacts of antimicrobials released into the environment requires an understanding of their sequestration by natural particles. Of particular interest are the strong interactions of antimicrobials with natural organic matter (NOM), which are believed to reduce their bioavailability, retard their abiotic and biotic degradation, and facilitate their persistence in soils and aquatic sediments. Molecular dynamics (MD) relaxation studies of a widely used fluoroquinolone antibiotic, ciprofloxacin (Cipro), interacting with a model humic substance (HS) in a hydrated environment, were performed to elucidate the mechanisms of these interactions. Specifically, a zwitterionic Cipro molecule, the predominant species at circumneutral pH, was reacted either with protonated HS or deprotonated HS bearing Ca, Mg, or Fe(II) cations. The HS underwent conformational changes through rearrangements of its hydrophobic and hydrophilic regions and disruption of its intramolecular H-bonds to facilitate favorable intermolecular H-bonding interactions with Cipro. Complexation of the metal cations with HS carboxylates appeared to impede binding of the positively charged amino group of Cipro with these negatively charged HS complexation sites. On the other hand, an outer-sphere complex between Cipro and the HS-bound cation led to ternary Cipro-metal-HS complexes in the case of Mg-HS and Fe(II)-HS, but no such bridging interaction occurred with Ca-HS. The results suggested that the ionic potential (valence/ionic radius) of the divalent cation may be a determining factor in the formation of the ternary complex, with high ionic potential favoring the bridging interaction. Environ. Toxicol. Chem. 2010;29:90-98. (c) 2009 SETAC.

  8. Novel humic acid-bonded magnetite nanoparticles for protein immobilization.

    Science.gov (United States)

    Bayrakci, Mevlut; Gezici, Orhan; Bas, Salih Zeki; Ozmen, Mustafa; Maltas, Esra

    2014-09-01

    The present paper is the first report that introduces (i) a useful methodology for chemical immobilization of humic acid (HA) to aminopropyltriethoxysilane-functionalized magnetite iron oxide nanoparticles (APS-MNPs) and (ii) human serum albumin (HSA) binding to the obtained material (HA-APS-MNPs). The newly prepared magnetite nanoparticle was characterized by using Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and elemental analysis. Results indicated that surface modification of the bare magnetite nanoparticles (MNPs) with aminopropyltriethoxysilane (APS) and HA was successfully performed. The protein binding studies that were evaluated in batch mode exhibited that HA-APS-MNPs could be efficiently used as a substrate for the binding of HSA from aqueous solutions. Usually, recovery values higher than 90% were found to be feasible by HA-APS-MNPs, while that value was around 2% and 70% in the cases of MNPs and APS-MNPs, respectively. Hence, the capacity of MNPs was found to be significantly improved by immobilization of HA. Furthermore, thermal degradation of HA-APS-MNPs and HSA bonded HA-APS-MNPs was evaluated in terms of the Horowitz-Metzger equation in order to determine kinetic parameters for thermal decomposition. Activation energies calculated for HA-APS-MNPs (20.74 kJmol(-1)) and HSA bonded HA-APS-MNPs (33.42 kJmol(-1)) implied chemical immobilization of HA to APS-MNPs, and tight interactions between HA and HA-APS-MNPs. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Advanced oxidation treatment and photochemical fate of selected antidepressant pharmaceuticals in solutions of Suwannee River humic acid

    International Nuclear Information System (INIS)

    Santoke, Hanoz; Song, Weihua; Cooper, William J.; Peake, Barrie M.

    2012-01-01

    Highlights: ► We elucidate the photochemical degradation of three antidepressant pharmaceuticals. ► Hydroxyl radical is the most significant contributor to the degradation. ► Excited state dissolved organic matter also plays a significant role for duloxetine. ► Tentative reaction byproducts are identified. - Abstract: Antidepressant pharmaceuticals have recently been detected at low concentrations in wastewater and surface water. This work reports studies of the direct and indirect photochemical fate and treatment by advanced oxidation of three antidepressant compounds (duloxetine, venlafaxine and bupropion) in solutions of humic acid in order to elucidate their behavior in the natural environment prior to reaching a water treatment facility and potentially entering a potable water supply. Humic acid solution was prepared by adding to distilled water a known amount of organic matter as a photosensitizer. All three antidepressants react very rapidly with hydroxyl radicals (·OH) and hydrated electrons (e − aq ) with rate constants of ∼10 8 to 10 10 M −1 s −1 , but significantly slower with singlet oxygen ( 1 ΔO 2 ) (∼10 3 to 10 5 M −1 s −1 ). The steady-state concentrations of ·OH and 1 ΔO 2 , in a sample of humic acid solution were measured and used with the second order rate constants to show that the hydroxyl radical was an order of magnitude more effective than the singlet oxygen in the solar-induced photochemical degradation of the antidepressants. Excited state dissolved organic matter also accounted for a substantial portion of degradation of duloxetine, decreasing its half-life by 27% under solar irradiation. Several reaction pathways and by-products arising from the photodegradation were identified using gamma-irradiation followed by LC–MS analysis.

  10. Advanced oxidation treatment and photochemical fate of selected antidepressant pharmaceuticals in solutions of Suwannee River humic acid

    Energy Technology Data Exchange (ETDEWEB)

    Santoke, Hanoz, E-mail: hsantoke@uci.edu [Urban Water Research Center, Department of Civil and Environmental Engineering, University of California, Irvine, Irvine, CA 92697-2175 (United States); Song, Weihua, E-mail: wsong@uci.edu [Urban Water Research Center, Department of Civil and Environmental Engineering, University of California, Irvine, Irvine, CA 92697-2175 (United States); Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433 (China); Cooper, William J., E-mail: wcooper@uci.edu [Urban Water Research Center, Department of Civil and Environmental Engineering, University of California, Irvine, Irvine, CA 92697-2175 (United States); Peake, Barrie M., E-mail: bpeake@chemistry.otago.ac.nz [Chemistry Department, University of Otago, P.O. Box 56, Dunedin 9054 (New Zealand)

    2012-05-30

    Highlights: Black-Right-Pointing-Pointer We elucidate the photochemical degradation of three antidepressant pharmaceuticals. Black-Right-Pointing-Pointer Hydroxyl radical is the most significant contributor to the degradation. Black-Right-Pointing-Pointer Excited state dissolved organic matter also plays a significant role for duloxetine. Black-Right-Pointing-Pointer Tentative reaction byproducts are identified. - Abstract: Antidepressant pharmaceuticals have recently been detected at low concentrations in wastewater and surface water. This work reports studies of the direct and indirect photochemical fate and treatment by advanced oxidation of three antidepressant compounds (duloxetine, venlafaxine and bupropion) in solutions of humic acid in order to elucidate their behavior in the natural environment prior to reaching a water treatment facility and potentially entering a potable water supply. Humic acid solution was prepared by adding to distilled water a known amount of organic matter as a photosensitizer. All three antidepressants react very rapidly with hydroxyl radicals ({center_dot}OH) and hydrated electrons (e{sup -}{sub aq}) with rate constants of {approx}10{sup 8} to 10{sup 10} M{sup -1} s{sup -1}, but significantly slower with singlet oxygen ({sup 1}{Delta}O{sub 2}) ({approx}10{sup 3} to 10{sup 5} M{sup -1} s{sup -1}). The steady-state concentrations of {center_dot}OH and {sup 1}{Delta}O{sub 2}, in a sample of humic acid solution were measured and used with the second order rate constants to show that the hydroxyl radical was an order of magnitude more effective than the singlet oxygen in the solar-induced photochemical degradation of the antidepressants. Excited state dissolved organic matter also accounted for a substantial portion of degradation of duloxetine, decreasing its half-life by 27% under solar irradiation. Several reaction pathways and by-products arising from the photodegradation were identified using gamma-irradiation followed by LC

  11. Humic substances. Part 2: Interactions with organisms.

    Science.gov (United States)

    Steinberg, Christian E W; Meinelt, Thomas; Timofeyev, Maxim A; Bittner, Michal; Menzel, Ralph

    2008-03-01

    Freshwater bodies which chemistry is dominated by dissolved humic substances (HS) seem to be the major type on Earth, due to huge non-calcareous geological formations in the Northern Hemisphere and in the tropics. Based on the paradigm of the inertness of being organic, direct interactions of dissolved HS with freshwater organisms are mostly neglected. However, dissolved organic carbon, the majority of which being HS, are natural environmental chemicals and should therefore directly interact with organisms. Major results that widened our perspective on humic substance ecology come from experiments with the compost nematode, Caenorhabditis elegans, which behaved contradictorily to textbook knowledge and provoked an in-depth re-consideration of some paradigms. To overcome old paradigms on HS and their potential interactions with organisms, we reviewed recent international literature, as well as 'grey' literature. We also include results from own ongoing studies. This review focuses on direct interactions of dissolved HS with freshwater organisms and disregards indirect effects, such as under-water light quenching. Instead we show with some macrophyte and algal species that HS adversely interfere with photosynthesis and growth, whereby closely related algal species show different response patterns. In addition to this, HS suppress cyanobacteria more than eukaryotic algae. Quinones in the HS appear to be the effective structure. Furthermore, HS can modulate the offspring numbers in the nematode C. elegans and cause feminization of fish and amphibians--they possess hormone-like properties. The ecological consequences of this potential remain obscure at present. HS also have the potential to act as chemical attractants as shown with C. elegans and exert a mild chemical stress upon aquatic organisms in many ways: induction of molecular chaperons (stress proteins), induction and modulation of biotransformation and anti-oxidant enzymes. Furthermore, they produce an

  12. Effects of humic substances on the migration of radionuclides: Complexation of actinides with humic substances. 3. Progress report

    International Nuclear Information System (INIS)

    Kim, J.I.; Rhee, D.S.; Buckau, G.; Moulin, V.; Tits, J.; Decambox, P.; Franz, C.; Herrmann, G.; Trautmann, N.; Dierckx, A.; Vancluysen, J.; Maes, A.

    1993-03-01

    The aim of the present research programme is to study the complexation behaviour of actinide ions with humic substances in natural aquifer systems and hence to quantify the effect of humic substances on the actinide migration. Aquatic humic substances commonly found in all groundwaters in different concentrations have a strong tendency towards complexation with actinide ions. This is one of the major geochemical reactions but hitherto least quantified. Therefore, the effect of humic substances on the actinide migration is poorly understood. In the present research programme the complexation of actinide ions with humic substances will be described thermodynamically. This description will be based on a model being as simple as possible to allow an easy introduction of the resulting reaction constants into geochemical modelling of the actinide migration. This programme is a continuation of the activities of the COCO group in the second phase of the CEC-MIRAGE project. The programme consists of the following three main tasks: Task 1: Complexation reactions of actinide ions with well characterized reference and site-specific humic and fulvic acids; Task 2: Competition reactions with major cations in natural groundwaters; Task 3: Validation of the complexation data in natural aquatic systems by comparison of calculation with spectroscopic experiment. (orig./EF)

  13. Determination of microscopic interactions between actinides and humic substances

    International Nuclear Information System (INIS)

    Brunel, Benoit

    2015-01-01

    Large amount of plutonium has been introduced into the environment as a result of nuclear weapons testing, and nuclear power-plant accidents. Contaminated areas, which need a particular survey, have become a very interesting place to study and understand the plutonium behaviour in the environment. Until few years ago, it was admitted that plutonium introduced into subsurface environment is relatively immobile, owing to its low solubility in ground water and strong sorption onto rocks. However, studies of contaminated areas show that humic substances, which are ubiquitous in environment, can alter the speciation of metal ion, e.g. plutonium, and thus their migration. These humic substances are major components of the natural organic matter in soil and water as well as in geological organic deposits such as lake sediments, peats and brown coals. They are complex heterogeneous mixtures of polydisperse supra-molecules formed by biochemical and chemical reactions during the decay and transformation of plant and microbial remains. The knowledge of the impact of humic substances on the plutonium migration is required to assess their transport in natural systems. However, due to the complex and heterogeneous nature of humic substances, there are a lot of difficulties in the description of microscopic interactions. The aim of this PhD thesis is to evaluate as precisely as possible interactions between actinides and humic substances. This work is divided in two parts: on the one hand humic substances will be separated to identify each component, on the other hand the speciation of actinides with characterized humic substances will be studied. In the first part of this study, new methods are developed to study the speciation of actinides with humic substances using two kinds of mass spectrometers: an ICP-MS and a high resolution mass spectrometer using various ionization devices (ESI, APCI, DART, APPI) in order to determine all active molecules for the complexation. In the

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. Potentiometric titration and equivalent weight of humic acid

    Science.gov (United States)

    Pommer, A.M.; Breger, I.A.

    1960-01-01

    The "acid nature" of humic acid has been controversial for many years. Some investigators claim that humic acid is a true weak acid, while others feel that its behaviour during potentiometric titration can be accounted for by colloidal adsorption of hydrogen ions. The acid character of humic acid has been reinvestigated using newly-derived relationships for the titration of weak acids with strong base. Re-interpreting the potentiometric titration data published by Thiele and Kettner in 1953, it was found that Merck humic acid behaves as a weak polyelectrolytic acid having an equivalent weight of 150, a pKa of 6.8 to 7.0, and a titration exponent of about 4.8. Interdretation of similar data pertaining to the titration of phenol-formaldehyde and pyrogallol-formaldehyde resins, considered to be analogs for humic acid by Thiele and Kettner, leads to the conclusion that it is not possible to differentiate between adsorption and acid-base reaction for these substances. ?? 1960.

  19. INFLUENCE OF BORATE BUFFERS ON THE ELECTROPHORETIC BEHAVIOR OF HUMIC SUBSTANCES IN CAPILLARY ZONE ELECTROPHORESIS

    Science.gov (United States)

    The influence of tetrahydroxyborate ions on the electrophoretic mobility of humic acids was evaluated by capillary electrophoresis (CE). Depending on the molarity of borate ions in the separation buffer, the humic acids exhibit electropherograms with sharp peaks consistently exte...

  20. Acid dissociation characteristics of humic acids

    International Nuclear Information System (INIS)

    Tochiyama, Osamu; Sakakibara, Tetsuro; Inoue, Yasushi

    1995-01-01

    Based on the results from potentiometric titrations carried out on polyacrylic acid and some commercially available humic acids, the equation for the proton dissociation of weak polymeric acids is proposed to be K app (H + )α/(1-α) = K 1/2 {(1-α)/α}((Na + )/(Na + ) s ), where α is the degree of dissociation, K 1/2 is the dissociation constant at α = 1/2, and the brackets with subscript s denote the concentration at the surface of the polymer. This equation has been derived on the assumptions: (i) Each polymer molecule is a polybasic acid (H N R N ) having different acidic sites with K values from K 1 to K N . (ii) Binding energies of protons on these sites are all equal. (iii) The ratios of the dissociation constants of H N-i R N i- and H N-j R N j- is expressed by K i /K j = {(N-i+1)/i}/{(N-j+1)/j} since the probabilities to release or bind a proton are proportional to the numbers of protons or numbers of available anionic sites on the polymer. (iv) The effective concentration of protons at the surface of the polymer ((H + ) s ) is related by (H + ) s /(H + ) = (Na + ) s /(Na + ), where (Na + ) s can be estimated by the relation, (Na + ) s = (Cl - ) s + (R - ) s (where (R - ) s Σi(H N-i R N i- )). This leads to (Na + ) s ≅ (Cl - ) s , which in turn leads to (Na + ) s ≅ (Na + ) at high ionic strength and (Na + ) s ≅ (R - ) s = C R α at low ionic strength. (author)

  1. 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).

  2. 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.

  3. Influence of lysozyme complexation with purified Aldrich humic acid on lysozyme activity

    NARCIS (Netherlands)

    Li, Y.; Tan, W.F.; Wang, M.X.; Liu, F.; Weng, L.P.; Norde, W.; Koopal, L.K.

    2012-01-01

    Humic acid is an important component of dissolved organic matter and in two previous papers it has been shown that purified Aldrich humic acid (PAHA) forms strong complexes with the oppositely charged protein lysozyme (LSZ). The complexation and aggregation of enzymes with humic acids may lead to

  4. Yields of potato and alternative crops impacted by humic product application

    Science.gov (United States)

    Humic substance (HA—humic acid, fulvic acid, and humin) are a family of organic molecules made up of long carbon chains and numerous active functional groups such as phenols and other aromatics. Humic substances play dynamic roles in soil physical, chemical biological functions essential to soil he...

  5. Lead binding to soil fulvic and humic acids: NICA-Donnan modeling and XAFS spectroscopy

    NARCIS (Netherlands)

    Xiong, J.; Koopal, L.K.; Tan, W.; Fang, L.; Wang, W.; Zhao, W.; Liu, T.; Zhang, J.; Weng, L.

    2013-01-01

    Binding of lead (Pb) to soil fulvic acid (JGFA), soil humic acids (JGHA, JLHA), and lignite-based humic acid (PAHA) was investigated through binding isotherms and XAFS. Pb binding to humic substances (HS) increased with increasing pH and decreasing ionic strength. The NICA-Donnan model described Pb

  6. 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...

  7. 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

  8. Effects of humic acids on the growth of bacteria

    Science.gov (United States)

    Tikhonov, V. V.; Yakushev, A. V.; Zavgorodnyaya, Yu. A.; Byzov, B. A.; Demin, V. V.

    2010-03-01

    The influence of humic acids of different origins on the growth of bacterial cultures of different taxa isolated from the soil and the digestive tracts of earthworms ( Aporrectodea caliginosa)—habitats with contrasting conditions—was studied. More than half of the soil and intestinal isolates from the 170 tested strains grew on the humic acid of brown coal as the only carbon source. The specific growth rate of the bacteria isolated from the intestines of the earthworms was higher than that of the soil bacteria. The use of humic acids by intestinal bacteria confirms the possibility of symbiotic digestion by earthworms with the participation of bacterial symbionts. Humic acids at a concentration of 0.1 g/l stimulated the growth of the soil and intestinal bacteria strains (66 strains out of 161) on Czapek’s medium with glucose (1 g/l), probably, acting as a regulator of the cell metabolism. On the medium with the humic acid, the intestinal bacteria grew faster than the soil isolates did. The most active growth of the intestinal isolates was observed by Paenibacillus sp., Pseudomonas putida, Delftia acidovorans, Microbacterium terregens, and Aeromonas sp.; among the soil ones were the representatives of the Pseudomonas genus. A response of the bacteria to the influence of humic acids was shown at the strain level using the example of Pseudomonas representatives. The Flexom humin preparation stimulated the growth of the hydrocarbon-oxidizing Acinetobacter sp. bacteria. This effect can be used for creating a new compound with the elevated activity of bacteria that are destroyers of oil and oil products.

  9. Studies of the Tc oxidation states in humic acid solutions

    International Nuclear Information System (INIS)

    Wang Bo; Liu Dejun; Yao Jun

    2010-01-01

    The oxidation state is an important aspect of the speciation of Tc in groundwater that contained organic substances due to it control the precipitation, complexation, sorption and colloid formation behavior of the Tc under HWL geological disposal conditions. In present work, the oxidation states of Tc were investigated using the LaCl 3 coagulation method and solution extraction method in aqueous solutions in which the humic acid concentration range is from 0 to 20 mg L -1 and the Tc (Ⅶ) concentration range is about 10 -8 mol l -1 . The radiocounting of 99 Tc was determined using liquid scintillation spectrometry. The humic acid will influence the radiocounting ratio of 99 Tc apparently, however, the quenching effect can be restrained once keep the volume of the cocktail to about twenty times of the sample volume. The LaCl 3 coagulation methods were carried out for the investigation of Tc oxidation states in humic acid aqueous systems at about pH 8. The tetraphenylarsonium chloride (IPA)-chloroform extraction method was used also simultaneously to investigation the concentrations of Tc (Ⅳ) and Tc (Ⅶ) for the availability of the LaCl 3 precipitation method, and the experimental results demonstrate that tetravalent technetium and pertechnetate concentrations are well agreement with the LaCl 3 precipitation method. These two experimental results demonstrated that Tc (Ⅶ) is very stable in the Tc (Ⅶ)-humic acid system during a 350 days experimental period, and the Tc (Ⅳ) concentrations are very lower, that is indicate that there didn't oxidizing reactions between the Fluka humic acid and Tc (Ⅶ) in aqueous solutions under anaerobic conditions. That is means the presence of humic acids even in anaerobic groundwater is disadvantage for the retardance of radionuclides. (authors)

  10. Studies of Tc oxidation states in humic acid solutions

    International Nuclear Information System (INIS)

    Wang Bo; Liu Dejun; Yao Jun

    2011-01-01

    The oxidation state of Tc is an important aspect of the speciation in groundwater which contained organic substances due to it control the precipitation, complexation, sorption and colloid formation behavior of the Tc under HWL geological disposal conditions. In present work, the oxidation states of Tc were investigated using the LaCl 3 coagulation method and solution extraction method in aqueous solutions in which the humic acid concentration range is from 0 to 20 mg/L and the Tc (VII) concentration is about 10 -8 mol/L. The radiocounting of 99 Tc was determined using liquid scintillation spectrometry. The humic acid will influence the radiocounting ratio of 99 Tc apparently, however, the quenching effect can be restrained once keep the volume of the cocktail to about twenty times of the sample volume. The LaCl 3 coagulation method was carried out for the investigation of Tc oxidation states in humic acid aqueous systems at about pH 8. The tetraphenylarsonium chloride (TPA)-chloroform extraction method was used also simultaneously to investigation the concentrations of Tc (IV) and Tc (VII) for the availability of the LaCl 3 precipitation method, and the experimental results demonstrate that tetravalent technetium and pertechnetate concentration are well agreement with the LaCl 3 precipitation method. These two experimental results demonstrated that Tc (VII) is very stable in the Tc (VII)-humic acid system during a 350 days experimental period, and the Tc (IV) concentrations are very lower, that is indicate that there didn't oxidizing reactions between the Fluka humic acid and Tc (VII) in aqueous solutions under anaerobic conditions. That means the presence of humic acids even in anaerobic groundwater is disadvantage for the retardance of radionuclides. (authors)

  11. [Distribution behaviors of phenanthrene to humic fractions in natural soil].

    Science.gov (United States)

    Lin, Xiu-mei; Pan, Bo; Liu, Wen-xin; Yuan, Hui-shi; Zhang, Xian-ming; Zhang, Yan-xu; Xiao, Yang; Dai, Han-cheng; Tao, Shu

    2006-04-01

    After adsorption of phenanthrene by the natural soil under different concentrations initially added, the soil sample was extracted for humic acid fraction (including humic acid and fulvic acid), and the sorption amount of phenanthrene in humin fraction was calculated to investigate the adsorption/distribution kinetics in two soil organic fractions and the corresponding influence of original phenanthrene concentration. The experimental data were fitted using Freundlich equation. The results show that, distribution of phenanthrene in the soil exhibited a multi-stage property, i.e., from a first fast sorption to a breakthrough at about 48 h, then followed by a slow sorption procedure. In the fast sorption stage (before 48 h), there was an up-to-down fluctuation of phenanthrene sorption ratio (sorption amount/added amount) in humic acid fraction, possibly due to surface sorption by minerals and competitive sorption by humin fraction. In the slow sorption stage, variations in sorption ratio in humic acid fraction was very small, and the influence of original concentration of phenanthrene was slight; while for humin fraction, the sorption ratio of phenanthrene at lower initial concentration was significantly higher than at higher one, in addition, the sorption ratio showed a gradually increasing trend, indicated humin fraction as the main domain in charge of the slow sorption. The fitting results of model parameters demonstrated that, sorption nonlinearity of phenanthrene in the natural soil increased in the following order: humic acid fractionsoilhumin fraction, and enhanced gradually. Different characteristics of humic acid and humin fractions in the multi-stage kinetics of phenanthrene sorption/distribution further reflected the effects of heterogenerity of soil organic fractions on nonlinear sorption behaviors.

  12. Catalysis of PAH biodegradation by humic acid shown in synchrotron infrared studies

    Energy Technology Data Exchange (ETDEWEB)

    Holman, Hoi-Ying N.; Nieman, Karl; Sorensen, Darwin L.; Miller, Charles D.; Martin, Michael C.; Borch, Thomas; McKinney, Wayne R.; Sims, Ronald C.

    2001-09-26

    The role of humic acid (HA) in the biodegradation of toxic polycyclic aromatic hydrocarbons (PAHs) has been the subject of controversy, particularly in unsaturated environments. By utilizing an infrared spectromicroscope and a very bright, nondestructive synchrotron photon source, we monitored in situ and, over time, the influence of HA on the progression of degradation of pyrene (a model PAH) by a bacterial colony on a magnetite surface. Our results indicate that HA dramatically shortens the onset time for PAH biodegradation from 168 to 2 h. In the absence of HA, it takes the bacteria about 168 h to produce sufficient glycolipids to solubilize pyrene and make it bioavailable for biodegradation. These results will have large implications for the bioremediation of contaminated soils.

  13. Determination of the protonation enthalpy of humic acid by calorimetric titration technique

    International Nuclear Information System (INIS)

    Kimuro, Shingo; Kirishima, Akira; Sato, Nobuaki

    2015-01-01

    Graphical abstract: The thermodynamic quantities of protonation of humic acid were determined by the combination of potentiometric titration and calorimetric titration. It was observed that the protonation enthalpy and Gibbs free energy had been affected by pH of solution. As a result, the thermodynamics of the protonation reaction of humic acid is influenced by the polyelectrolyte effect and the heterogeneity. - Highlights: • We applied calorimetric titration technique to the protonation of humic acid. • The thermodynamic quantities of protonation of humic acid were determined. • The protonation enthalpy of humic acid is affected by the heterogeneity. • Gibbs free energy of the protonation is affected by the polyelectrolyte effect. - Abstract: In this study, the calorimetric titration technique was used to determine the protonation enthalpy of two reference humic acids and polyacrylic acid. First, we obtained the apparent protonation constant of two kinds of humic acid purchased from IHSS (International Humic Substances Society) and polyacrylic acid by potentiometric titration. Second, we obtained the protonation enthalpy of them by calorimetric titration. The protonation enthalpy of humic acid was affected by pH and the ionic strength of bulk solution. From the comparison of ΔH between humic acid and polyacrylic acid, it was concluded that the pH dependence of ΔH is attributed to the heterogeneity of humic acid. And ΔH of phenolic hydroxyl group in humic acid is strongly influenced by the electric double layer of humic acid’s surface. This is considered to be a reason of the ionic strength dependence of ΔH. On the other hand, Gibbs free energy of the protonation of humic acid is affected by the electrostatic attraction with the progress of dissociation of functional groups such as carboxyl group and phenolic hydroxyl group. Consequently, the thermodynamics of the protonation of humic acid is affected by the polyelectrolyte effect and the

  14. Isolation of humic acid from oxidized lignite and complexation with metal cations

    Directory of Open Access Journals (Sweden)

    Ćatović Benjamin

    2017-01-01

    Full Text Available Lignite is brown coal, which in its composition contains humic acids. Humic acids are produced by coal combustion, which leads to the enrichment of coal humic acids. Lignite, from the opet pit mine Šikulje, lignite ore „Kreka“, Bosnia and Herzegovina, was fragmented and sieved to the appropriate size and used as a base material. The isolation of humic acid was carried out from pre-oxidized and dried lignite after which it was refined. Identification thus obtained humic acids was carried out by FTIR spectroscopy and its characterization of UV analysis which is determined by optical density of isolated humic acid and its complexation with metal cations. Data obtained by FTIR spectroscopic analysis of isolated humic acids show no significant structural and chemical difference in relation to the spectrum obtained for standard humic acids (Sigma Aldrich. UV analysis showed that isolated and standard humic acid have E4/E6 ratio in an appropriate range of 3–5, which indicates the presence of a large number of aliphatic structure. Based on the degree of humification was found that the isolated humic acids belong to the type B standard while humic acids belong to type A. The most important property of the humic substances is the ability to interact with the metal ions forming soluble or insoluble complexes which possess different chemical and biological properties and stability. The nature of the complex between humic acid and metal cation derived from the heterogeneous, polyelectric and polydispersive character humic acids that occurs due to the presence of a large number of functional groups. Complexation of humic acid is carried out with different concentrations of metal nitrate solutions and at different pH values. Different amounts of humic acids were used for the complexation. The amount of the free metal ions was measured with the ICP-OES methode. The data were also statistically analyzed with ANOVA. The results showed that increasing the p

  15. 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.

  16. Attenuation of polychlorinated biphenyl sorption to charcoal by humic acids

    NARCIS (Netherlands)

    Koelmans, A.A.; Meulman, B.; Meijer, T.; Jonker, M.T.O.

    2009-01-01

    Strong sorption to black carbon may limit the environmental risks of organic pollutants, but interactions with cosorbing humic acid (HA) may interfere. We studied the attenuative effect of HA additions on the sorption of polychlorinated biphenyls (PCBs) to a charcoal. "Intrinsic" sorption to

  17. Can humic products become mainstream amendments for improving crop production?

    Science.gov (United States)

    Humic products have been used in cropland production for several decades but only by small numbers of farmers. Appreciable proportions of field studies demonstrate efficacy of the products for numerous crops, justifying their further evaluation. Their adoption by mainstream farmers could be accelera...

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

    African Journals Online (AJOL)

    The evaluation in root architecture change was performed by analyzing the main root axis length, lateral root length, density of lateral roots, fresh and dry mass weight of roots and estimated H+-ATPase activity by specific root acidification measurement. The results indicate that all humic materials extracted from mangrove ...

  19. Temperature Induced Aggregation and Clouding in Humic Acid Solutions

    Directory of Open Access Journals (Sweden)

    Leah Shaffer

    2015-01-01

    Full Text Available Humic acids in aqueous solution demonstrate inverse temperature-solubility relationships when solution conditions are manipulated to reduce coulombic repulsion among the humic polyanions. These effects were followed by dynamic light scattering (DLS measurements of the resulting aggregates, as well as the addition of a polarity sensitive fluorescent probe (pyrene. The humic solutions could be primed for temperature induced clouding by carefully lowering the pH to a point where hydration effects became dominant. The exact value of the cloud point (CP was a function of both pH and humate concentration. The CPs mostly lay in the range 50–90°C, but DLS showed that temperature induced aggregation proceeded from approximately 30°C onward. Similar effects could be achieved by adding multivalent cations at concentrations below those which cause spontaneous precipitation. The declouding of clouded humate solutions could be affected by lowering the temperature combined with mechanical agitation to disentangle the humic polymers.

  20. Coagulation of some humic acid solutions by Moringa oleifera Lam ...

    African Journals Online (AJOL)

    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. ... (coagulation of both surface water and distilled water containing a suspension of mineral particles) deal mainly with the effect of some ... metals, pesticides, etc.) inside the water [11, 12].

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

    African Journals Online (AJOL)

    The performance of each species was compared by examining spore production in oat medium, and the significant medium components and fermentation conditions were identified using Plackett and Burman statistical design. For both Trichoderma species, the results indicate that humic acids production can be enhanced ...

  2. Fractionation of humic acid upon adsorption to goethite

    NARCIS (Netherlands)

    Qin, Xiaopeng; Liu, Fei; Wang, Guangcai; Hou, Hong; Li, Fasheng; Weng, Liping

    2015-01-01

    The fractionation and replacement of humic acid (HA) during its interactions with goethite (or goethite-coated sand) were conducted using batch and column experiments. The weight-average molecular weight (Mw) of HA in solutions was determined by a high performance size exclusion chromatography

  3. Humic acids of vermicompost as an ecological pathway to increase ...

    African Journals Online (AJOL)

    Humic acids of vermicompost as an ecological pathway to increase resistance of rice seedlings to water stress. ... Changes in plant anatomy and morphology before and after stress initiation were employed as biomarkers of plant response. The growth rate over time, water content, dry-mass content, leaf carbohydrates, ...

  4. Attenuation of polychlorinated biphenyl sorption to charcoal by humic acids.

    NARCIS (Netherlands)

    Koelmans, A.A.; Meulman, B.; Meijer, T.; Jonker, M.T.O.

    2009-01-01

    Strong sorption to black carbon may limit the environmental risks of organic pollutants, but interactions with cosorbing humic acid (HA) may interfere. We studied the attenuative effect of HA additions on the sorption of polychlorinated biphenyls (PCBs) to a charcoal. "Intrinsic" sorption to

  5. Determination of carboxyl groups in humic acids by FTIR spectrophotometry

    Czech Academy of Sciences Publication Activity Database

    Novák, František; Machovič, V.; Poledna, J.

    2005-01-01

    Roč. 1, č. 1 (2005), s. 141 ISSN 1336-7242. [Zjazd chemických spoločností /57./. 04.09.2005-08.09.2005, Tatranské Matliare] Institutional research plan: CEZ:AV0Z60660521 Keywords : carboxyl groups * humic acids * FTIR spectrophotometry Subject RIV: EH - Ecology, Behaviour

  6. Europium (III) and americium (III) stability constants with humic acid

    International Nuclear Information System (INIS)

    Torres, R.A.; Choppin, G.R.

    1984-01-01

    The stability constants for tracer concentrations of Eu(III) and Am(III) complexes with a humic acid extracted from a lake-bottom sediment were measured using a solvent extraction system. The organic extractant was di(2-ethylhexyl)-phosphoric acid in toluene while the humate aqueous phase had a constant ionic strength of 0.1 M (NaClO 4 ). Aqueous humic acid concentrations were monitored by measuring uv-visible absorbances at approx.= 380 nm. The total carboxylate capacity of the humic acid was determined by direct potentiometric titration to be 3.86 +- 0.03 meq/g. The humic acid displayed typical characteristics of a polyelectrolyte - the apparent pKsub(a), as well as the calculated metal ion stability constants increased as the degree of ionization (α) increased. The binding data required a fit of two stability constants, β 1 and β 2 , such that for Eu, log β 1 = 8.86 α + 4.39, log β 2 = 3.55 α + 11.06 while for Am, log β 1 = 10.58 α + 3.84, log β 2 = 5.32 α + 10.42. With hydroxide, carbonate, and humate as competing ligands, the humate complex associated with the β 1 constant is calculated to be the dominant species for the trivalent actinides and lanthanides under conditions present in natural waters. (orig.)

  7. Compost effect on soil humic acid: A NMR study.

    Science.gov (United States)

    Adani, Fabrizio; Genevini, Pierluigi; Tambone, Fulvia; Montoneri, Enzo

    2006-11-01

    The humic acid (HA) fraction of a food and vegetable residues compost (CM) was taken as indicator to trace the fate of CM organic matter in four years CM amended soil. (1)H and (13)C NMR spectroscopy were used to investigate the nature of the HA isolates from CM, control soil (S(4)) and amended soil. The result indicated a significant structural difference between CM HA and S(4) HA, and supported the presence of both HA fractions in soil at the end of the amendment trials. However, the nature and content of CM HA in soil did not fully explain the increase of soil cation exchange capacity (CEC) after amendment. All CM humic fractions (i.e., fulvic acid, humic acid and humin) were found to contribute to the change of the soil organic matter composition. It is concluded that although CM HA is a suitable indicator of the survival of compost organic matter in soil during amendment, all three humic fractions should be monitored and analyzed to fully understand changes in the composition and properties of amended soil.

  8. Adsorption of humic acid on acid-activated Greek bentonite.

    Science.gov (United States)

    Doulia, Danae; Leodopoulos, Ch; Gimouhopoulos, K; Rigas, F

    2009-12-15

    The adsorption of humic acid on bentonite from Milos Island (Greece) acid-treated with dilute H(2)SO(4) solutions over a concentration range between 0.25 and 13M has been studied. Bentonite activated with 3M sulfuric acid (AAS) showed a higher efficiency in removing humic acid from aqueous solutions and was selected for further investigation. The specific surface area of acid-activated bentonite was estimated using the methylene blue adsorption method. The morphology of untreated, activated, and HA-sorbed bentonite was studied under scanning electron microscope (SEM). The effects of contact time, adsorbate concentration, adsorbent dose, and temperature on the adsorption of humic acid onto bentonite activated with 3M H(2)SO(4) were studied using a batch adsorption technique. Acidic pH and high ionic strength proved to be favorable for the adsorption efficiency. Pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were used to describe the kinetic data and the rate constants were evaluated. The experimental isotherm data were analyzed using Langmuir, Freundlich, and Temkin equations and the isotherm constants were determined. Thermodynamic parameters (DeltaH(o), DeltaS(o), and DeltaG(o)) of adsorption of humic acid onto acid-activated bentonite with 3M sulfuric acid were also evaluated.

  9. Influence of vermicompost humic acid on chlorophyll content and ...

    African Journals Online (AJOL)

    Vermicompost humic acids (VHA) promote plants' growth because they have similar effects with auxins. The aim of this research was to evaluate the effect of VHA in some physiological indicators in the micropropagation and acclimatization phase of banana clone Enano Guantanamero. Six concentrations were used (0, 10, ...

  10. On the radiocesium behavior in a small humic lake (Lithuania)

    International Nuclear Information System (INIS)

    Tarasiuk, N.; Koviazina, E.; Karpicz, R.; Moisejenkova, A.; Astrauskiene, N.

    2009-01-01

    Peculiarities of radiocesium contamination of a small humic lake, which became meromictic some thirty-five years ago due to the inflow of a large amount of humic water, are presented. The lake consists of two separate water layers, which do not intermix. A lower water layer of the lake below some 3-m depth is stagnant and anaerobic, and radiocesium load of the sediments is mainly caused by nuclear weapons fallout. The radiocesium load of the sediments of the upper monomictic water layer is significantly larger due to additional contamination after the Chernobyl accident. Radiocesium activity concentrations in lake water increase with depth, and even in the surface layer, they are commonly the largest among the neighboring lakes with transparent water. It is shown that bottom areas of the monomictic part of the lake with the elevated radiocesium deepening into sediments are related to the favorite sites of the tench (Tinca tinca) winter torpor. Sediment bioturbation and redistribution due to tench activities distort naturally formed radiocesium vertical profiles and they cannot be used for estimations of sedimentation rates and sediment chronology. The studied lake can be useful as an analogous model in analyzing structural and radiological consequences of humic water inflows to closed lakes. Concerning extreme radiological situations in closed humic lakes related to their specific vertical structure, they may be treated as critical objects in assessing the risk to humans after radionuclide deposition events. (authors)

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

    African Journals Online (AJOL)

    leonardo

    Brasileira de Bioquímica e Biologia Molecular (SBBQ 2008). Águas de Lindóia, SP, Brasil. Anais, SBBQ 2008. CD-ROM. Dobbss LB, Canellas LP, Olivares FL, Aguiar NO, Peres LEP, Azevedo. M, Spaccini R, Piccolo A, Façanha AR (2010). Bioactivity of chemically transformed humic matter from vermicompost on plant.

  12. Can humic water discharge counteract eutrophication in coastal waters?

    Directory of Open Access Journals (Sweden)

    Agneta Andersson

    Full Text Available A common and established view is that increased inputs of nutrients to the sea, for example via river flooding, will cause eutrophication and phytoplankton blooms in coastal areas. We here show that this concept may be questioned in certain scenarios. Climate change has been predicted to cause increased inflow of freshwater to coastal areas in northern Europe. River waters in these areas are often brown from the presence of high concentrations of allochthonous dissolved organic carbon (humic carbon, in addition to nitrogen and phosphorus. In this study we investigated whether increased inputs of humic carbon can change the structure and production of the pelagic food web in the recipient seawater. In a mesocosm experiment unfiltered seawater from the northern Baltic Sea was fertilized with inorganic nutrients and humic carbon (CNP, and only with inorganic nutrients (NP. The system responded differently to the humic carbon addition. In NP treatments bacterial, phytoplankton and zooplankton production increased and the systems turned net autotrophic, whereas the CNP-treatment only bacterial and zooplankton production increased driving the system to net heterotrophy. The size-structure of the food web showed large variations in the different treatments. In the enriched NP treatments the phytoplankton community was dominated by filamentous >20 µm algae, while in the CNP treatments the phytoplankton was dominated by picocyanobacteria <5 µm. Our results suggest that climate change scenarios, resulting in increased humic-rich river inflow, may counteract eutrophication in coastal waters, leading to a promotion of the microbial food web and other heterotrophic organisms, driving the recipient coastal waters to net-heterotrophy.

  13. Fungal treatment of humic-rich industrial wastewater: application of white rot fungi in remediation of food-processing wastewater.

    Science.gov (United States)

    Zahmatkesh, Mostafa; Spanjers, Henri; van Lier, Jules B

    2017-11-01

    This paper presents the results of fungal treatment of a real industrial wastewater (WW), providing insight into the main mechanisms involved and clarifying some ambiguities and uncertainties in the previous reports. In this regard, the mycoremediation potentials of four strains of white rot fungi (WRF): Phanerochaete chrysosporium, Trametes versicolor, Pleurotus ostreatus and Pleurotus pulmonarius were tested to remove humic acids (HA) from a real humic-rich industrial treated WW of a food-processing plant. The HA removal was assessed by color measurement and size-exclusion chromatography (SEC) analysis. T. versicolor showed the best decolorization efficiency of 90% and yielded more than 45% degradation of HA, which was the highest among the tested fungal strains. The nitrogen limitation was studied and results showed that it affected the fungal extracellular laccase and manganese peroxidase (MnP) activities. The results of the SEC analysis revealed that the mechanism of HA removal by WRF involves degradation of large HA molecules to smaller molecules, conversion of HA to fulvic acid-like molecules and also biosorption of HA by fungal mycelia. The effect of HS on the growth of WRF was investigated and results showed that the inhibition or stimulation of growth differs among the fungal strains.

  14. Humic substances, their microbial interactions and effects on biological transformations of organic pollutants in water and soil: A review.

    Science.gov (United States)

    Lipczynska-Kochany, Ewa

    2018-03-17

    Depicted as large polymers by the traditional model, humic substances (HS) tend to be considered resistant to biodegradation. However, HS should be regarded as supramolecular associations of rather small molecules. There is evidence that they can be degraded not only by aerobic but also by anaerobic bacteria. HS presence alters biological transformations of organic pollutants in water and soil. HS, including humin, have a great potential for an application in aerobic and anaerobic wastewater treatment as well as in bioremediation. Black carbon materials, including char (biochar) and activated carbon (AC), long recognized effective sorbents, have been recently discovered to act as effective redox mediators (RM), which may significantly accelerate degradation of organic pollutants in a way similar to HS. Humic-like coating on the biochar surface has been identified. Explanation of mechanisms and possibility of applications of black carbon materials have only started to be explored. Results of many original and review papers, presented and discussed in this article, show an enormous potential for an interesting, multidisciplinary research as well as for a development of new, green technologies for biological wastewater treatment and bioremediation. Future research areas have been suggested. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. Processing of humic-rich riverine dissolved organic matter by estuarine bacteria: effects of predegradation and inorganic nutrients

    DEFF Research Database (Denmark)

    Asmala, E.; Autio, R.; Kaartokallio, H.

    2014-01-01

    inorganic nitrogen and phosphorus than without addition (on average 13.5 % and 9.0, respectively), but had no effect on the degradation of fresh, non-predegraded, DOC (%BDOC 12.0 %). Bacterial growth efficiency (BGE) was highest (65 ± 2 %) in the units with fresh DOM, and lowest in units with predegraded...... of predegradation and the inorganic nutrient status in the receiving estuary has consequences to carbon cycling and will determine the amount of terrestrial-derived DOC being ultimately assimilated into marine food webs......The bioavailability of predegraded dissolved organic matter (DOM) from a humic-rich, boreal river to estuarine bacteria from the Baltic Sea was studied in 39-day bioassays. The river waters had been exposed to various degrees of bacterial degradation by storing them between 0 and 465 days in dark...

  16. The Separation of Humic Substances by Membrane Polysulfone Method

    International Nuclear Information System (INIS)

    AW, Muhadi; Muzakky; PS, Diana

    2000-01-01

    The separation of humic substances by polysulfone has been done. Thisinvestigation aims at separating the humic substances contained in theestuary environment. Because of without sample pre-treatment, cheap and easythis method has been to choice. At preliminary study proved that byincreasing the pressure until 50 psia, the yield of flux was 13.5 l/m 2 .jamand the reject coefficient was 90.98%, so that polysulfone membrane isappropriate to be applied. More over the pressure could be increased morethan 50 psia. The feed concentration should be lower than 150 ppm, though thevolume should be greater. The pH condition should be alkaline (pH> 7), sinceat this condition the filtration process is easily conducted and the rejectcoefficient could reach 95.09%. (author)

  17. Reduced humic acid nanosheets and its uses as nanofiller

    Science.gov (United States)

    Duraia, El-shazly M.; Henderson, B.; Beall, Gary W.

    2015-10-01

    Leonardite is highly oxidized form of lignite coal and contains a number of carboxyl groups around the edges of a graphene-like core. A novel approach has been developed to synthesize graphene oxide-like nanosheets in large scale utilizing leonardite as a starting material. Humic acid extracted from leonardite has been reduced by performing a high pressure catalytic hydrogenation. The reaction was carried out inside a high pressure stirred reactor at 150 °C and 750 psi (~5.2×106 Pa). Morphology of the as-synthesized samples showed porous platy particles and EDAX analysis indicates the carbon and oxygen atomic ratios as 96:4-97:3%. The as-synthesized material has been used as nanofiller in polyurethane. The reduced humic acid-polyurethane nanocomposite showed over 250% increase of Young's modulus. This new approach provides a low cost and scalable source for graphene oxide-like nanosheets in nanocomposite applications.

  18. Structure and properties of natural humic substances of the oxyhumolite type

    Energy Technology Data Exchange (ETDEWEB)

    Vesela, L.; Kubal, M.; Kozler, J.; Innemanova, P. [Dekonta Co., Prague (Czech Republic). Division for Remedial & Environmental Projects

    2005-07-01

    Humic substances are naturally occurring organic compounds formed by decomposition of organic matter and by synthetic activities of microorganisms. Humic acids, fulvic acids and humin are major components of humic substances. Oxyhumolite (oxidised young lignite) is a natural, inert and non-toxic material, which can contain up to 90% of biochemically active humic substances. One of the top-quality oxyhumolites is in the Czech Republic. Some of the North-Bohemian oxyhumolites contain more than 80% of humic acids with low contents of bitumen (< 0.1 %) and inorganics. Due to their structure and suitable properties, these substances appear to be applicable in detoxication of contaminants present in the environment. Natural humic substances are suitable for sorption, ion exchange and biodegradation processes.

  19. Phenanthrene sorption to sequentially extracted soil humic acids and humins.

    Science.gov (United States)

    Kang, Seunghun; Xing, Baoshan

    2005-01-01

    Humic substances strongly influence the environmental fate of hydrophobic organic chemicals in soils and sediments. In this study, the sorption of phenanthrene by humic acids (HAs) and humins was examined. HAs were obtained from progressively extracting a soil, eight times with 0.1 M Na4P207 and two times with 0.1 M NaOH solution, and then the residue was separated into two humin fractions by their organic carbon contents. The chemical and structural heterogeneity of the HAs and humins were characterized by elemental analysis, ultraviolet-visible spectroscopy, diffuse reflectance infrared Fourier transform spectroscopy, and solid-state 13C NMR. There were significant chemical and structural differences among the HA fractions and humins; the later extracted HAs had relatively high aliphatic carbons content. All sorption data were fitted to a Freundlich equation, S = K(F)C(N), where S and C are the sorbed and solution-phase concentrations, respectively, and K(F) and N are constants. All of the phenanthrene sorptions were nonlinear, and the nonlinearity decreased with further extractions from 0.90 (first extracted HA) to 0.96 (ninth HA) and was the lowest (0.88) for the higher organic carbon content humin. Phenanthrene sorption coefficient by HAs significantly increased with progressive extractions, being the highest for the humins. For HAs isotherms, a positive trend was observed between the sorption coefficient and the aliphaticity, but a negative relation was shown between the nonlinearity and the aliphaticity and between the sorption capacity and polarity of HAs. Phenanthrene sorption was greatly affected by chemical structure and composition of humic substances, even from a same soil. In addition, polarity of humic substances seems to mainly regulate the magnitude of phenanthrene sorption rather than structure.

  20. Humic acids quality of Cambisols developed on gneiss and amphibolite

    Czech Academy of Sciences Publication Activity Database

    Pospíšilová, Ľ.; Žigová, Anna; Šťastný, Martin; Liptaj, T.

    2012-01-01

    Roč. 9, č. 4 (2012), s. 503-510 ISSN 1214-9705 R&D Projects: GA ČR GA526/08/0434 Institutional support: RVO:67985831 Keywords : Cambisols * parent material * arable soil, * grassland soil * X-ray diffraction * humic acids * SRATR FTIR and 13C NMR spectroscopy Subject RIV: DF - Soil Science Impact factor: 0.530, year: 2011 http://www.irsm.cas.cz/materialy/acta_content/2012_04/8.Pospisilova.pdf

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

    African Journals Online (AJOL)

    USER

    2010-03-29

    Mar 29, 2010 ... Imidacloprid sorption of the treated soils was studied at three pH levels (4.5, 6.0 and 7.5) and two temperatures (15 and 25°C). Soil imidacloprid adsorption was related to pH and the type and quantity of added HAs. Humic acid (HA) and fulvic acid (FA) derived from peat had different effects on adsorption.

  2. Formation of humic substances in weathered MSWI bottom ash.

    Science.gov (United States)

    Zhang, Haixia; Shimaoka, Takayuki

    2013-01-01

    The study aimed at evaluating the humic substances (HSs) content from municipal solid waste incinerator (MSWI) bottom ash and its variation with time and the effect of temperature on HSs formation. The process suggested by IHSS was applied to extract HSs from two different bottom ash samples, and the extracted efficiency with NaOH and Na4P2O7 was compared. MSWI bottom ash samples were incubated at 37°C and 50°C for 1 year. HSs and nonhumic substances were extracted from the bottom ash sample with different incubated period by 0.1 M NaOH/Na₄P₂O₇. Results show that the rate of humic acid formation increased originally with incubation time, reached a maximum at 12th week under 37°C and at 18th week under 50°C, and then decreased with time. More humic acid in MSWI bottom ash was formed under 50°C incubated condition compared with that incubated under 37°C. Also, the elemental compositions of HSs extracted from bottom ash are reported.

  3. 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.

  4. Formation of Humic Substances in Weathered MSWI Bottom Ash

    Directory of Open Access Journals (Sweden)

    Haixia Zhang

    2013-01-01

    Full Text Available The study aimed at evaluating the humic substances (HSs content from municipal solid waste incinerator (MSWI bottom ash and its variation with time and the effect of temperature on HSs formation. The process suggested by IHSS was applied to extract HSs from two different bottom ash samples, and the extracted efficiency with NaOH and Na4P2O7 was compared. MSWI bottom ash samples were incubated at 37∘C and 50∘C for 1 year. HSs and nonhumic substances were extracted from the bottom ash sample with different incubated period by 0.1 M NaOH/Na4P2O7. Results show that the rate of humic acid formation increased originally with incubation time, reached a maximum at 12th week under 37∘C and at 18th week under 50∘C, and then decreased with time. More humic acid in MSWI bottom ash was formed under 50∘C incubated condition compared with that incubated under 37∘C. Also, the elemental compositions of HSs extracted from bottom ash are reported.

  5. Sorption of tebuconazole onto selected soil minerals and humic acids.

    Science.gov (United States)

    Cadková, Eva; Komárek, Michael; Kaliszová, Regina; Koudelková, Věra; Dvořák, Jiří; Vaněk, Aleš

    2012-01-01

    The aim of the present study was to investigate tebuconazole sorption on common soil minerals (birnessite, ferrihydrite, goethite, calcite and illite) and humic acids (representing soil organic matter). Tebuconazole was used (i) in the commercial form Horizon 250 EW and (ii) as an analytical grade pure chemical. In the experiment with the commercially available tebuconazole, a significant pH-dependent sorption onto the oxides was observed (decreasing sorption with increasing pH). The highest sorption was found for ferrihydrite due to its high specific surface area, followed by humic acids, birnessite, goethite and illite. No detectable sorption was found for calcite. The sorption of analytical grade tebuconazole on all selected minerals was significantly lower compared to the commercial product. The sorption was the highest for humic acids, followed by ferrihydrite and illite and almost negligible for goethite and birnessite without any pH dependence. Again, no sorption was observed for calcite. The differences in sorption of the commercially available and analytical grade tebuconazole can be attributed to the additives (e.g., solvents) present in the commercial product. This work proved the importance of soil mineralogy and composition of the commercially available pesticides on the behavior of tebuconazole in soils.

  6. 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)

  7. Biotransformation of coal derived humic acids by Basidiomycetes

    Science.gov (United States)

    Klein, O. I.; Kulikova, N. A.; Stepanova, E. V.; Koroleva, O. V.

    2009-04-01

    Introduction Low energetic coals and wastes of coal industry are promising sources for biologically active compounds including humic acids (HA). Aside from evident advantages of biocatalytic approaches for coal slime conversion such as environmental safety and cost efficiency they also could be used for the improving of HAs biological activity [1, 2]. The aim of the present study was to provide molecular characterization of the HAs formed during biotransformation of coal slime by Basidiomycetes under different cultivation conditions. Materials and methods Biotransformation of brown coal from Solncevskoe deposit (Sakhalin, Russia) was performed by liquid surface cultivation of pure culture Coriolus hirsutus 075 (Wulf. Ex. Fr.) Quel. with rich (contained glucose as a carbon source) and poor (without readily available carbon source) nutrition medium. After 30 days of cultivation coal HAs were separated by alkaline extraction followed by dialysis desalting and drying at 50C. HAs derived were characterized using size-exclusion chromatography, Fourier transformed infrared (FTIR) and 13C NMR spectroscopy. Results and discussion Molecular weight distribution of HA was not significantly affected by Basidiomycetes under all cultivation conditions studied in comparison to HAs extracted from non-conversed coal. FTIR spectra of HA obtained were typical for HAs. Biotransformation of coal did not result in appearance of new functional groups. The exception was observed under rich media conditions where absorbance at 1700 cm-1 was determined related to carbonyl groups of carboxyl and ketonic fragments. Therefore, the revealed phenomena could be explained with additional formation of the above carbonyl groups in the course of biotransformation process. Quantification of 13C NMR spectra revealed decrease of aromatic structures in HA extracted from coal after biotransformation under poor media conditions. Also a significant increase in carboxylic fragments content was observed. So

  8. Acceleration on the Growth of Rubber Planting Materials by Using Foliar Application of Humic Acid

    OpenAIRE

    Cahyo, Andi Nur; Ardika, Risal; Saputra, Jamin; Wijaya, Thomas

    2014-01-01

    The best rubber planting materials are needed to build the best rubber plantation. Humic acids could be used to improve the growth of rubber planting materials. Humic acid plays a role as a hormone-like substance. This research was aimed to determine the optimal concentration of foliar application of humic acid in order to enhance the growth of rubber tree planting materials. This research was arranged in a completely randomized block design with five treatments and four replicates. The treat...

  9. Association constants of modified humic acids with biocides of the triazole series: Cyproconazole and tebuconazole

    Science.gov (United States)

    Mal'Tseva, E. V.; Yudina, N. V.; Chaikovskaya, O. N.; Nechaev, L. V.

    2011-09-01

    The interaction of humic acids with biocides of triazoles in dependence on the concentration of components in solutions was investigated by spectrofluorimetry. The complex behavior of intermolecular interactions between biocides and humic acids, including donor-acceptor and hydrophobic bonds, was established. The effect of conditions of mechanochemical modification of humic acids and pH on the efficiency of interaction with biocides is shown.

  10. Study on the Effects of Humic Acid on Germination of Four Wheat Cultivars (Triticun aestivum L.)

    OpenAIRE

    S Sabzevari; H Khazaie; M Kafi

    2011-01-01

    Abstract Humic acid is an organic acid without environmental destructive effects that is applied for increasing germination rate and wheat establishment. In order to evaluate effects of different levels of humic acid on germination of four wheat cultivars; an experiment was conducted in 2008 at Research Laboratory of Faculty of Agriculture, Ferdowsi University of Mashhad. A randomized completely block design with four replications used with factorial combination of humic acid concentrati...

  11. The effect of various chemical treatments on the pyrolytic pattern of peat humic acid

    Energy Technology Data Exchange (ETDEWEB)

    Almendros, G.; Martin, F.; Gonzalez-Vila, F.J.; Delrio, J.C. (CSIC, Madrid (Spain). Centro de Ciencies Medioambientales)

    1993-06-01

    The present study describes the pyrolytic patterns of a series of humic preparations obtained from a peat humic acid subjected to chemical modifications, such as methylation, oximation, sulphonation, nitration, amidation, ammonia fixation, acetylation, acid and alkaline hydrolysis, hydrogen peroxide treatment, etc. Some diagnostic pyrolysis compounds were found which can be useful in studying N speciation in humic substances. In addition, the noticeable differences in the distribution patterns of the alkeyl series released upon pyrolysis were interpreted in terms of the changes introduced in the structural arrangement of the humic macromolecules.

  12. The measurement of the molecular weight of humic acid by ultracentrifugation

    International Nuclear Information System (INIS)

    Gardner, M.P.

    1989-07-01

    This report is concerned with the application of ultracentrifuge methods to the determination of humic acid molecular weights. The work has been undertaken as part of the Co-Co club intercomparison exercise on humic acid characterisation. Knowledge of the molecular weight distribution of humic acid will be an important parameter in assessing the likely physical and chemical behaviour under the near-field environment. Molecular weights of a sample of purified Aldrich humic acid have been obtained by sedimentation velocity and sedimentation equilibrium studies using an analytical ultracentrifuge. The results have shown the material to be polydisperse with a weight average molecular weight in the region 2700 to 4000. (author)

  13. Humic acid provenance influence to the adsorption capacity in uranium and thorium removal

    Science.gov (United States)

    Prasetyo, E.

    2018-01-01

    It is common knowledge that humic acid is organic compound without certain chemical composition since it is derived from different organic materials. Further this raises question whether the different humic acid sample used could lead to different adsorbent properties e.g. adsorption capacity. To address the problem, this paper is aimed to clarify the relation between the provenances of humic acid and synthesized adsorbent properties especially adsorption capacities by quantitative and qualitative functional groups determination including discussion on their effect to the metal ion adsorption mechanism using three humic acid samples. Two commercial samples were derived from recent compost while the other extracted from tertiary carbonaceous mudstone strata.

  14. Effects of humic substances on the migration of radionuclides: Complexation of actinides with humic substances. 4. progress report

    International Nuclear Information System (INIS)

    Czerwinski, K.; Buckau, G.; Scherbaum, F.; Kim, J.I.; Moulin, V.; Decambox, P.; Moulin, C.; Marquardt, C.; Franz, C.; Herrmann, G.; Trautmann, N.; Dierckx, A.; Vancluysen, J.; Apers, K.; Maes, A.

    1993-09-01

    In this report a number of methodical developments are in progress. The effective ligand concentration is one of the important parameters for the evaluation of the metal ion complexation behaviour of bulk polyelectrolytes like humic or fulvic acids. Studies by KUL and TUM show that the effective ligand concentration of humic acid is related to the protonation of the ion exchanging groups. For a precise evaluation of the complexation reaction, however, a direct measurement of the effective ligand capacity under given experimental conditions is neccessary. The humate complexation has been studied for pentavalent neptunium (UM), hexavalent uranium (TUM) and trivalent lanthanide ions (CEA, UM and KUL) under different experimental conditions. The pH is varied between 3.0 and 9.0, the ionic strength between 0.01 and 0.1 M with metal ion concentrations between 10 -13 and 10 -5 mol/L. Competition of Al 3+ , [Co(NH 3 ) 6 ] 3+ , Ca 2+ , Cu 2+ , Fe 2+ and Na + on the Eu humate interaction is investigated by KUL. CEA-FAR has studied the influence of temperature on the Dy(III) humate complexation as well as the Dy(III) complexation with EDTA for the purpose of comparison. Studies by KUL on the influence of different competing ligands show that in such a ternary system (metal ion, humic acid and competing ligand) mixed complexes are generated. (orig.)

  15. 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

    , but also the plant type Environmentally stressful conditions, rather than the plant type, played a more prominent role in shaping the root growth response to HS. This finding is especially relevant to the agronomic use of HS, because soil degradation, climate change and diminishing water and nutrient resources are becoming increasingly important constraints to agriculture production, and recommendations for using HS are often directed at alleviating these stresses. Blanco-Canqui, H. and Lal R., Mechanisms of Carbon Sequestration in Soil Aggregates, Critical Reviews in Plant Sciences, 2004, 23 (6), 481-504 MacCarthy, Patrick, Soil Science, The Principles of Humic Substances, 2001, 166 (11), 738-751 Quilty J.R. and Cattle S.R., Use and understanding of organic amendments in Australian agriculture: a review, Soil Research, 2011, 49(1) 1-26

  16. 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

  17. Application of Spectroscopic Techniques (FT-IR, 13C NMR) to the analysis of humic substances in volcanic soils along an environmental gradient (Tenerife, Canary Islands, Spain)

    Science.gov (United States)

    Rodriguez Rodriguez, Antonio; María Armas Herrera, Cecilia; González Pérez, José Antonio; González-Vila, Francisco Javier; Arbelo Rodríguez, Carmen Dolores; Mora Hernández, Juan Luis; Polvillo Polo, Oliva

    2010-05-01

    Andosols and andic soils are considered as efficient C-sinks in terms of C sequestration. These soils are usually developed from volcanic materials, and are characterized by a predominance of short-range ordered minerals like allophanes, imogolite and other Fe and Al oxyhydroxides. Such materials occur commonly associated with organic compounds, thus generating highly stable organo-mineral complexes and leading to the accumulation of a high amount of organic carbon. Spectroscopic methods like FT-IR and 13C NMR are suitable for the analysis of the chemical structure of soil humic substances, and allow identifying distinct functional groups and protein, lipids, lignin, carbohydrate-derived fragments. In this work we study the structural features of four soils developed on Pleistocene basaltic lavae in Tenerife (Canary Island, Spain), distributed along an altitudinal climatic gradient. The soil sequence comprises soils with different degree of geochemical evolution and andic character, including a mineral ‘Hypersalic Solonchak' (Tabaibal de Rasca), a slightly vitric ‘Luvic Phaeozem' (Los Frailes), a degraded and shallow ‘Endoleptic, fulvic, silandic Andosol' (Siete Lomas), and a well-developed and deep ‘Fulvic, silandic, Andosol' (Ravelo). Samples of the raw soil and humic and fulvic acids isolated from the surface horizons were analyzed. The results show a low content of organic carbon in the mineral soil, the inherited humin predominating, and a very high content of humic and fulvic acids in Andosols. The FT-IR and 13C NMR spectra of the raw soil samples show a low resolution, related to interferences from mineral complexes signals, particularly in soils with lower organic carbon content. 13C NMR shows a predominance of O-alkyl carbon (derived of carbohydrates) in andic soils, whereas O-alkyl and aromatic fractions are most evident in the mineral soil. The humic acids spectra are characterized by a dominance of alkyl and aromatic fractions with a high degree

  18. Humic Haplustox under different land uses in a high altitude environment in the Agreste region of Pernambuco, Brazil

    Directory of Open Access Journals (Sweden)

    Jane Kelly Silva Araujo

    2014-08-01

    Full Text Available The Garanhuns Plateau in the Agreste region of the State of Pernambuco, Brazil is characterized by humid climatic conditions due to orographic rains, unlike the surrounding semiarid region. These soils are subjected to intense agricultural use and are extremely important for the regional economy. This study was carried out in the municipality of Brejão in the Agreste region with the aim of assessing changes in humic Haplustox soils subjected to different land uses. Four plots with different vegetation covers (native forest, secondary shrubby vegetation (capoeira, traditional cropping system, and planted pasture were selected, and samples were taken from a soil profile and four small pits surrounding it at each site. Physical and chemical properties were assessed, including aggregate stability, humic organic fractions, and a microbiological evaluation through determination of basal respiration, microbial biomass carbon, and metabolic quotient. The soils under study showed physical and chemical properties typical of a Haplustox, such as low nutrient content, low cation exchange capacity, and high levels of acidity and Al saturation. The total organic carbon (TOC contents were high regardless of the type of land use. Aggregates < 2 mm were dominant in all the conditions under study. The TOC content was higher in the soil under capoeira, 43.91 g kg-1 on the surface, while 34.36 and 33.43 g kg-1 of TOC were observed in the first layer of forest and pasture soils, respectively. While the microbial biomass C (MBC was greater than 700 mg kg-1 in the forest and pasture areas (in the 0-5 cm layer, and 588 mg kg-1 in the soil under capoeira, these numbers were not statistically different. In the cultivated soil area, there was a reduction of around 28 % in TOC and MBC contents. Agricultural activity contributed to degradation of the humic horizon, as can be seen from a significant decrease in the TOC and changes in the relative distribution of the humic

  19. 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.

  20. Decomposition characteristics of humic-like matters with the hollow ellipsoid structure sludge inoculated from decayed soil in mature landfill leachate.

    Science.gov (United States)

    Zhang, Jie; Lan, Sijie; Niu, Dongjie; Zhao, Youcai

    2016-01-01

    The organics in mature leachate are mainly humic-like matters, which account for over 80% weight of the total organics. In this work, the microorganisms in decayed soil were found to be capable of decomposing the humic-like matters evidently using an anaerobic-aerobic/anoxic bioprocess in two sequencing bio-reactors. The 3D excitation-emission matrix and Fourier transform infrared (FT-IR) were applied to characterize the variation of dissolved organic matters in mature leachate while sludge morphology was characterized by scanning electron microscopy. The intensities of fluorescence peaks A and C of leachate effluents were 71.66% and 48.75% lower than those of influents, respectively, which indicated the extraordinary degradation ability of microorganisms inoculated from the decayed soil. Meanwhile a kind of distinctive hollow ellipsoid structure sludge organized by tiny soil particles was observed, which might favour the humic-like matters' decomposition and has never been reported before as we know. The formation mechanisms of hollow ellipsoid structure sludge will need further study.

  1. Amide and Ester-Functionalized Humic Acid for Fuel Combustion Enhancement

    Science.gov (United States)

    Riggs, Mark

    Humic acid is a class of naturally occurring molecules composed of large sheet-like regions of cyclic aromatic hydrocarbon networks with surface and edge functional groups including phenols, carboxylic acids, and epoxides. These naturally occurring molecules are found in brown coal deposits near lignite formations. Humic acid has gained attention from the scientific community as a precursor for graphene. Graphene is a 2-dimensional honeycomb structure of fully unsaturated carbon atoms that has exceptional material properties and inherent aromaticity. Graphene's incredible properties are matched by the difficulty associated with reproducibly manufacturing it on a large scale. This issue has limited the use of graphene for commercial applications. The polar functional groups of humic acid contribute to the hydrophilic nature of the molecule, limiting its miscibility in any alkyl-based solvent. Surfactants containing long alkyl chains can affect the miscibility of the molecule in an organic solvent. Surfactants are often difficult to remove from the system. It is theorized that alkylation of the functional sites of humic acid can affect the hydrophilic nature of the molecule, and effectively enable its dispersion into organic solvents without simultaneous incorporation of surfactants. This dissertation investigated the amidation and esterification of humic acid molecules extracted from leonardite. The resulting change in the modified humic acid dispersibility in organic solvents and its potential usage as a fuel additive were evaluated. Butyl, hexyl, octyl, and decyl amide-modified and ester-modified humic acids were synthesized. These products were characterized to confirm successful chemical reaction through thermogravimetric analysis, Fourier-transform infrared spectroscopy, and scanning electron microscopy. The decyl-modified humic acids remained suspended in kerosene mixtures for longer than 1 week. Other organo-humic acids showed varying degrees of flocculation

  2. Optimized Extraction Method To Remove Humic Acid Interferences from Soil Samples Prior to Microbial Proteome Measurements.

    Science.gov (United States)

    Qian, Chen; Hettich, Robert L

    2017-07-07

    The microbial composition and their activities in soil environments play a critical role in organic matter transformation and nutrient cycling. Liquid chromatography coupled to high-performance mass spectrometry provides a powerful approach to characterize soil microbiomes; however, the limited microbial biomass and the presence of abundant interferences in soil samples present major challenges to proteome extraction and subsequent MS measurement. To this end, we have designed an experimental method to improve microbial proteome measurement by removing the soil-borne humic substances coextraction from soils. Our approach employs an in situ detergent-based microbial lysis/TCA precipitation coupled to an additional cleanup step involving acidified precipitation and filtering at the peptide level to remove most of the humic acid interferences prior to proteolytic peptide measurement. The novelty of this approach is an integration to exploit two different characteristics of humic acids: (1) Humic acids are insoluble in acidic solution but should not be removed at the protein level, as undesirable protein removal may also occur. Rather it is better to leave the humics acids in the samples until the peptide level, at which point the significant differential solubility of humic acids versus peptides at low pH can be exploited very efficiently. (2) Most of the humic acids have larger molecule weights than the peptides. Therefore, filtering a pH 2 to 3 peptide solution with a 10 kDa filter will remove most of the humic acids. This method is easily interfaced with normal proteolytic processing approaches and provides a reliable and straightforward protein extraction method that efficiently removes soil-borne humic substances without inducing proteome sample loss or biasing protein identification in mass spectrometry. In general, this humic acid removal step is universal and can be adopted by any workflow to effectively remove humic acids to avoid them negatively competing

  3. [Forming mechanism of humic acid-kaolin complexes and the adsorption of trichloroethylene].

    Science.gov (United States)

    Zhu, Xiao-jing; He, Jiang-tao; Su, Si-hui

    2015-01-01

    The interaction between soil organic components and mineral components was explored in this study. Humic acid and kaolin were used for the preparation of organic-mineral complexes with different contents of organic matter, for experimental study of the adsorption of trichloroethylene. The results showed that the adsorption of trichlorethylene fitted the Freundlich isotherm model. The existence of interaction between humic acid and kaolin was indicated by the significant difference between the actual value and the theoretically overlaid value of the adsorption capacity. With various characterizations, such as FTIR and surface area & pore analysis, the mechanism of interaction between humic acid and kaolin was suggested as follows. When their contents were low, humic acid molecules firstly loaded on the surface binding sites of kaolin. Then with the content increased, as O/M( organic-mineral mass ratio) was 0.02-0.04, some surface pores of kaolin were filled by part of the molecules. After reaching a relatively stable stage, as O/M was 0.04-0.08, humic molecules continued to load on the surface of kaolin and formed the first humic molecule-layer. With humic acid content continued increasing, as O/M was 0.08-0.10, more humic molecules attached to kaolin surface through the interaction with the first layer of molecules and then formed the second layer. O/M was 0.10-0.16 as the whole second layer stage, meanwhile the first layer was compressed. Then when O/M was 0.16-0.4, there were still some humic loadings onto the second layer as the third layer, and further compressed the inner humic acid layers. Besides, some humic acid molecules or aggregates might go on attaching to form as further outer layer.

  4. Chemical nature of humic substances in two typical Chinese soils (upland vs paddy soil): A comparative advanced solid state NMR study.

    Science.gov (United States)

    Xu, Jisheng; Zhao, Bingzi; Chu, Wenying; Mao, Jingdong; Zhang, Jiabao

    2017-01-15

    Knowledge of the structural features of humic substances (HSs) is essential for elucidating the mechanisms of humification in different soil environments and realizing their profound roles in environmental issues. The aim of this work was to investigate the chemical structures of fulvic acid (FA), humic acid (HA) and humin (HM) fractions isolated from an upland soil (Fluvisol) and a paddy soil (Anthrosol) typical in China using advanced solid-state 13 C nuclear magnetic resonance (NMR) techniques. The results revealed that there were great structural differences of HSs between the two soils. The two FAs showed distinct quantitative differences in aliphatics with more polysaccharides in the FA from the upland soil than from the paddy soil. The HM from the upland soil differed from the paddy soil HM in having more proteins/peptides (23% vs 20%), total aromatics (21% vs 12%) as well as fewer lipids (24% vs 35%) and polysaccharides (27% vs 31%). The HM fractions represented the most different components of organic matter between the two soils. The degree of difference between the two HAs fell in between that of FAs and HM fractions. In particular, the HA from the upland soil had relatively greater degree of aromaticity. Our study indicated that the upland soil exhibited a higher degree of humification compared with the paddy soil. Among the three humic fractions, the FAs featured COO/N-CO groups, and the HAs were more enriched in protonated aromatic C for both soils. In contrast, the two HM fractions contained more O-alkyl C and fewer aromatics than did the other humic fractions, being closer to the original organic materials in soils. We speculate that the evolutionary route of HSs is likely to be the transformation of original organic materials into HM, followed by increased degradation, further oxidization and conversion into HA, and then into FA. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Evaluation of the Efficiency of Electron Beam Irradiation for Removal of Humic Acid from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Mohammad hasan Ehrampoosh

    2017-05-01

    Full Text Available Background: Humic acids (HAs have adverse effects on the environment; therefore, they should be removed from the water and wastewater. The aim of this study was to evaluate the efficiency of the electron beam irradiation for removal of humic acid from aqueous solutions. Methods: Humic acid was purchased from Sigma-Aldrich Company. After preparation of stock solution in alkaline condition, different concentrations of humic acid (10, 25 and 50 mg were prepared. Study has done at pH= 8 and in different dose rates of 1, 3, 6, 9 and 15 kGy. Then initial absorption of samples was measured at 254 nm using UV-Visible spectrophotometer before and after the irradiation. Excel and SPSS Ver. 18 were used for analyzing the data and drawing graphs. Results: The results of this study showed that by increasing adsorbed dose from 1 to 15 kGy, the efficiency of HA removal increased and by increasing humic acid concentration from 10 to 50 mg/L, the removal efficiency of humic acid decreased. The results of the kinetic study showed that irradiation of humic acid followed pseudo second-order reaction. Conclusion: It can be concluded that electron beam irradiation can be a useful technology for the treatment of environmental samples contaminated by humic acid.

  6. Effects of Humic Acid on the Germination Traits of Pumpkin Seeds under Cadmium Stress

    Directory of Open Access Journals (Sweden)

    Maasoumeh ASADI

    2013-12-01

    Full Text Available The study tackled the effect of humic acid and cadmium concentrations on the pumpkin seed germination characteristics throughout were studied. Treatments were cadmium concentrations on three levels: 0, 100 and 200 ppm and humic acid concentration of 0, 100, 200, 300 and 400 mg lit-1. Results showed that interaction of humic acid and cadmium was not significant on germination traits, but there was a significant effect on seedling growth indexes. Radicle and plumule length increased by 86 and 192% in comparison with control, of the mixture of 200 ppm cadmium and 300 mg lit-1 of humic acid. Cadmium had stimulatory effect on radicle and cotyledon dry weight and the highest values obtained with 200 ppm in mixture with 200 mg lit-1 of humic acid. Also, maximum plumule dry weight was recorded in 200 ppm cadmium and 300 mg lit-1 of humic acid. The highest of indexes were observed of 200 ppm cadmium and 400 mg lit-1 humic acid. In conclusion, the humic acid had detoxifying effect on cadmium stress in the culture and responded antagonistically against cadmium, but it seems that these concentrations of cadmium are low for the pumpkin seed and can be increased in order to reach the toxicity level.

  7. Removal of Natural Organic Matter from Two Types of Humic Ground Waters by Nanofiltration

    DEFF Research Database (Denmark)

    Alborzfar, Maryam; Jonsson, Gunnar Eigil; Grøn, Christian

    1998-01-01

    The efficiency of nano filtration (NF) in producing drinking water from two types of humic ground waters was studied on site at a pilot scale in Denmark. At one site, the natural organic matter (NOM) consisted almost entirely of humic acids with a concentration of 20-22 mg C/l, a broad molecular...

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

    African Journals Online (AJOL)

    2016-08-17

    Aug 17, 2016 ... 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.

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

    African Journals Online (AJOL)

    Jane

    2011-06-22

    Jun 22, 2011 ... humic substances. Some researchers found that humic acid increased the yields in some plants. Studies have shown that this substance has caused yield increase of. 22 to 23% (Adani et al., 1998) and 36.3% (Togun and. Akanbi, 2003) in tomato, 32.5 to 42.5% in maize (Tan and Binger, 1986), 10 to 30% ...

  10. Organic carbon and humic acids in sediments of the Arabian Sea and factors governing their distribution

    Digital Repository Service at National Institute of Oceanography (India)

    Sardessai, S.

    Organic carbon and humic acids in the sediments of the Arabian Sea show distinct regional variations to the south and north of 15~'N latitude. Significant variations are also observed from the shelf to the slope regions. Organic carbon and humic...

  11. Simultaneous analysis of small organic acids and humic acids using high performance size exclusion chromatography

    NARCIS (Netherlands)

    Qin, X.P.; Liu, F.; Wang, G.C.; Weng, L.P.

    2012-01-01

    An accurate and fast method for simultaneous determination of small organic acids and much larger humic acids was developed using high performance size exclusion chromatography. Two small organic acids, i.e. salicylic acid and 2,3-dihydroxybenzoic acid, and one purified humic acid material were used

  12. 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

  13. 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

  14. Mitigation of Humic Acid Inhibition in Anaerobic Digestion of Cellulose by Addition of Various Salts

    NARCIS (Netherlands)

    Azman, S.; Khadem, A.F.; Zeeman, G.; Lier, van J.B.; Plugge, C.M.

    2015-01-01

    Humic compounds are inhibitory to the anaerobic hydrolysis of cellulosic biomass. In this study, the impact of salt addition to mitigate the inhibitory effects of humic compounds was investigated. The experiment was conducted using batch tests to monitor the anaerobic hydrolysis of cellulose in the

  15. Application of the NICADonnan model for proton, copper and uranyl binding to humic acid

    NARCIS (Netherlands)

    Saito, T.; Nagasaki, S.; Tanaka, S.; Koopal, L.K.

    2004-01-01

    Humic acids are natural organic materials that play an important role in the migration of heavy metal and actinide ions in aquatic and soil systems. In the present study, the binding of protons, copper ions and uranyl ions to the purified Aldrich humic acid (PAHA) is investigated and the results are

  16. Flow column experiments on the migration characteristics of dissolved humic acids in sediments of different grain size

    International Nuclear Information System (INIS)

    Klotz, D.

    2001-01-01

    Humic acids dissolved in water can be retained in sediments by sorption and filtration. The resulting retardation depends on the properties of the humic acids (composition, concentration) and sediments (specific surface, pore geometry). The deposition/solution of humic acids affects the pore geometry and thus the hydraulic characteristics of the sediments [de

  17. Carbon and Nitrogen Stocks and Humic Fractions in Brazilian Organosols

    Directory of Open Access Journals (Sweden)

    Gustavo Souza Valladares

    Full Text Available ABSTRACT Despite limited geographic expression of Organosols in Brazil, their high carbon storage capacity and natural environmental vulnerability justifies further studies on C and N stocks in these soils and their relationship to the nature of organic matter. Evaluation of physical and chemical properties of organic soils and their ability to store C is important so as to develop sustainable management practices for their preservation. The objectives of the study were to measure the total organic carbon stock (OCst, total nitrogen stock (Nst, and humic fractions in Organosols from different environments and regions of Brazil, and to correlate the data with soil chemical (pH, P, K, Ca2+, Mg2+, Al3+, H+Al, CEC, V and physical properties (soil bulk density, Bd; organic matter density, OMd; total pore space, TPS; minimum residue, MinR; and proportion of mineral matter, MM, and degree of organic matter decomposition (rubbed fiber content; pyrophosphate index, PyI; and von Post index. For that purpose, 18 Organosol profiles, in a total of 49 horizons, were sampled under different land usage and plant coverage conditions. The profiles were located in the following Brazilian states - Alagoas, Bahia, Distrito Federal, Espírito Santo, Mato Grosso do Sul, Minas Gerais, Paraná, Rio de Janeiro, Rio Grande do Sul, Santa Catarina, and São Paulo. The OCst and Nst varied significantly among horizons and profiles. The Organosols exhibited, on average, 203.59 Mg ha-1 OCst and 8.30 Mg ha-1 Nst, and the highest values were found in profiles with pasture usage. The content of the humic fraction (humin, HUM; fulvic acid, FAF; and humic acid, HAF and C storage varied in the soil horizons and profiles according to the degree of decomposition and other factors of soil formation. The OCst, Nst, OMd and the C stocks in the humic fractions were positively correlated. The values of acidity were lower in the soils with higher contents of mineral material, and low p

  18. Effects on humic substances on the migration of radionuclides: Complexation of actinides with humic substances in natural aquatic systems. Appendix IV

    International Nuclear Information System (INIS)

    Dierckx, A.; Vancluysen, J.; Maes, A.

    1994-01-01

    In this working period, we focused mainly on a possible influence of competing cations on the Eu 3+ -humic acid interaction. Two scenario's were considered. Firstly, the humic acid is fully occupied by the competing cation. From this type of experiments, it became clear that upon coagulation the ensuing kinetics become very important. Experiments concerning this behaviour are running and will be reported later. Furthermore, it can be concluded that the order of influence of the competing cations on the Eu 3+ -humic acid interaction, follows the order of interaction strength of the competing cation with the humic acid (Na + 3 ) 6 ) 3+ 2+ 2+ 3+ ∼Cu 2+ ∼Al 3+ ). Secondly, a novel method was tested to investigate the influence of competing cation concentrations, not sufficient to fully occupy the humic acid. An 'indifferent' cation (Co(NH 3 ) 6 ) 3+ , was used to coagulate the humic acid in order to hinder its diffusion through the membrane. The results obtained in presence and in absence of (Co(NH 3 ) 6 ) 3+ agree with each other but are too preliminary to publish in this progress report. (orig.)

  19. 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

  20. Pine Harvest Impact on Soil Structure of a Dystric Cambisol (Humic

    Directory of Open Access Journals (Sweden)

    Adriano da Costa

    2016-01-01

    Full Text Available ABSTRACT Traffic of heavy machinery at harvest and log extraction causes structural degradation of the soil, but studies on the effects of forest harvesting on soils with high organic matter content and exchangeable Al are scarce. The objective of this study was to evaluate the effect of mechanized forest harvesting operations on a Dystric Cambisol (Humic with high organic matter (more 50 g kg1 content and exchangeable Al (more 6,0 cmolc kg-1, reforested with Pinus taeda L. The evaluated harvesting system were the whole-tree, in which the feller-buncher cuts and lays the trees down in bundles; the skidder drags the tree bundles up near a road; and the harvester delimbs and cuts the trees into short logs, stacking them on the roadside to be loaded onto trucks. The areas were evaluated for soil conditions at pre-harvest, prior to harvest, and at post-harvest, consisting of areas of low disturbance, high disturbance, forest residues and log yards. The effects of compaction after forest harvesting are observed by the decrease in total porosity (especially biopores and macropores, soil saturated hydraulic conductivity, and stability of aggregates. After forest harvesting, soil compaction was observed in all evaluated situations, but with different depths depending on operation type and the intensity of traffic carried in each area.

  1. Atrazine biodegradation modulated by clays and clay/humic acid complexes

    International Nuclear Information System (INIS)

    Besse-Hoggan, Pascale; Alekseeva, Tatiana; Sancelme, Martine; Delort, Anne-Marie; Forano, Claude

    2009-01-01

    The fate of pesticides in the environment is strongly related to the soil sorption processes that control not only their transfer but also their bioavailability. Cationic (Ca-bentonite) and anionic (Layered Double Hydroxide) clays behave towards the ionisable pesticide atrazine (AT) sorption with opposite tendencies: a noticeable sorption capacity for the first whereas the highly hydrophilic LDH showed no interactions with AT. These clays were modified with different humic acid (HA) contents. HA sorbed on the clay surface and increased AT interactions. The sorption effect on AT biodegradation and on its metabolite formation was studied with Pseudomonas sp. ADP. The biodegradation rate was greatly modulated by the material's sorption capacity and was clearly limited by the desorption rate. More surprisingly, it increased dramatically with LDH. Adsorption of bacterial cells on clay particles facilitates the degradation of non-sorbed chemical, and should be considered for predicting pesticide fate in the environment. - The biodegradation rate of atrazine was greatly modulated by adsorption of the pesticide and also bacterial cells on clay particles.

  2. Effect of humic acid on photocatalytic activity of ZnO nanoparticles.

    Science.gov (United States)

    Chandran, Preethy; Netha, Suhas; Sudheer Khan, S

    2014-09-05

    Zinc oxide nanoparticles (ZnO NPs) are widely used in consumer products including sunscreens, textiles and paints. The indiscriminate use of such materials may leads to its release into the environment. The present study evaluated the photocatalytic effect of ZnO NPs in presence of humic acid (HA), which is an important factor present largely in the environment. ZnO NPs were characterized by using UV-visible spectrophotometer, scanning electron microscopy, particle size analyzer and X-ray diffraction analysis. The mean diameter of the particles was found to be 55±2.1 nm. The XRD patterns exhibited hexagonal structure for ZnO NPs. The photocatalytic activity of ZnO NPs was evaluated based on the change in UV-visible absorption spectra of the methylene blue solution as a function of reaction time under visible light source. The rate of photocatalytic degradation of methylene blue was decreased with increase in HA concentration. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Effects of Soil Management Practices on Water Erosion under Natural Rainfall Conditions on a Humic Dystrudept

    Directory of Open Access Journals (Sweden)

    Vinicius Ferreira Chaves de Souza

    Full Text Available ABSTRACT Water erosion is the main cause of soil degradation and is influenced by rainfall, soil, topography, land use, soil cover and management, and conservation practices. The objective of this study was to quantify water erosion in a Humic Dystrudept in two experiments. In experiment I, treatments consisted of different rates of fertilizer applied to the soil surface under no-tillage conditions. In experiment II, treatments consisted of a no-tillage in natural rangeland, burned natural rangeland and natural rangeland. Forage turnip, black beans, common vetch, and corn were used in rotation in the treatments with crops in the no-tillage during study period. The treatments with crops and the burned rangeland and natural rangeland were compared to a bare soil control, without cultivation and without fertilization. Increasing fertilization rates increased organic carbon content, soil resistance to disintegration, and the macropore volume of the soil, due to the increase in the dry mass of the crops, resulting in an important reduction in water erosion. The exponential model of the ŷ = ae-bx type satisfactorily described the reduction in water and soil losses in accordance with the increase in fertilization rate and also described the decrease in soil losses in accordance with the increase in dry mass of the crops. Water erosion occurred in the following increasing intensity: in natural rangeland, in cultivated natural rangeland, and in burned natural rangeland. Water erosion had less effect on water losses than on soil losses, regardless of the soil management practices.

  4. Effect of humic acids on electricity generation integrated with xylose degradation in microbial fuel cells

    DEFF Research Database (Denmark)

    Huang, Liping; Angelidaki, Irini

    2008-01-01

    to controls where HAs were not added, addition of commercial HA resulted in increase of power density and coulombic efficiency, which ranged from 7.5% to 67.4% and 24% to 92.6%, respectively. Digested manure wastewater (DMW) was tested as potential mediator for power generation due to its content of natural...... HA, and although it could produce higher coulombic efficiency namely 32.2% than the control of 18.3%, showed lower power density which was approx. 57 mW/m2 in comparison to power density of the control which was 69 mW/m2. Presence of commercial HA or DMW in the anode chamber resulted in faster xylose...... feedstocks for MFCs, containing both mediators and substrates, such as lignocellulose hydrolysates should be considered for their applicability in MFCs. Biotechnol. Bioeng. 2008;100: 413-422. © 2008 Wiley Periodicals, Inc....

  5. Humic and hymatomelanic acids interaction with lanthanide ions

    Science.gov (United States)

    Jerzykiewicz, Maria

    2012-10-01

    The interactions of lanthanide ions, REE(III), with semiquinone radicals naturally occurring in humic (HA) and hymatomelanic (HY) acids of different origin were studied mainly by EPR spectroscopy. Quantitative EPR analysis proved that only the semiquinone free radical concentration in both, HA and HY, was affected by interaction with some of the lanthanide ions, whereas the EPR g parameters of the formed radical-REE(III) complexes remained unchanged. The radical concentration was practically unaffected by the REE(III) ions with 4f1-4f6 electron configurations and in some degree increased by REE(III) ions with 4f8-4f14 configuration. The lanthanide playing an exceptional role was Gd(III) (4f7), which diminished strongly the free radicals concentration. The quenching ability of Gd(III) was stronger towards the radicals provided by HA than by HY, what was assigned to higher content in HA of both, oxygen-containing functional groups and conjugated aromatic rings, leading to more efficient Gd(III)-radical interaction. The semiquinone free radicals of HA and HY originated from the compost were more reactive than those from peat, as the humic acids from mature compost with less bulk density have more accessible functional groups.

  6. Phenanthrene sorption to soil humic acid and different humin fractions.

    Science.gov (United States)

    Wen, Bei; Zhang, Jing-Jing; Zhang, Shu-Zhen; Shan, Xiao-Quan; Khan, Shahamat U; Xing, Baoshan

    2007-05-01

    This study was undertaken to provide an insight into the effect of heterogeneous soil organic matter (SOM) on the sorption of phenanthrene. Humic acid (HA) and humin were extracted from a peat soil. Humin was further fractionated into bound-humic acid (BHA), lipid, and insoluble residue (IR) fractions. Heterogeneous natures of these fractions were characterized by elemental analysis, ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, and solid-state 13C NMR. Aliphaticity of the fractions followed the order lipid >BHA > HA > IR, while the polarity order was IR > BHA> HA > lipid. Sorption of phenanthrene on these fractions fitted the Freundlich equation, suggesting that phenanthrene sorption isotherms of lipid were almost linear (N = 0.993), while those of HA, BHA, and IR were nonlinear, with N values ranging from 0.723 to 0.910. The N values followed the order lipid > HA > BHA > IR and were significantly correlated inversely with their polarities (p Organic carbon-normalized sorption coefficients (K(FOC)) were independent of aliphatic or aromatic contents of the SOM fractions. The results suggested that SOM, especially for the humin fractions, was highly heterogeneous in terms of elemental composition, structure, and polarity. Such heterogeneity was considered to be responsible forthe nonlinear sorption of phenanthrene.

  7. Radiation decomposition of humic substances in landfill disposal leachate

    International Nuclear Information System (INIS)

    Sawai, Takeshi; Sawai, Teruko; Shimokawa, Toshinari

    1979-01-01

    The leachate generated from landfill contains humic substances such as humic acid and fluvic acid. It shows, in general, high chemical oxygen demand (COD) and biological oxygen demand (BOD), and colors in dark brown. When the leachate collected on the No. 15 landfill in Tokyo Bay was irradiated by γ-rays from a 60 Co source in bubbling air, the total organic carbon (TOC) decreased with increasing dose and the brown color was bleached. The effects of pH, flow rate, and dose rate on the decrease of TOC, the variations of UV spectrum, and the formation of carbon dioxide by the irradiation were examined. The decreasing rate of TOC increased with an increase of the flow rate up to -- 11/min and showed a maximum value in the region of pH 4 - 6. It was also dependent on the dose rate and increased with a decrease of the dose rate. The radiation chemical yield, G(-TOC), reached 162 at low dose rate of 1.3 x 10 4 rad/h. This result suggests that a radiation-induced chain reaction occurred. The amount of TOC decreased was almost equal to that of carbon dioxide formed. This result shows that the organic substances were decomposed by irradiation to carbon dioxide as a final product and it was ejected from the solution. (author)

  8. Properties and structure of raised bog peat humic acids

    Science.gov (United States)

    Klavins, Maris; Purmalis, Oskars

    2013-10-01

    Humic substances form most of the organic components of soil, peat and natural waters, and their structure and properties differ very much depending on their source. The aims of this study are to characterize humic acids (HAs) from raised bog peat, to evaluate the homogeneity of peat HAs within peat profiles, and to study peat humification impact on properties of HAs. A major impact on the structure of peat HAs have lignin-free raised bog biota (dominantly represented by bryophytes of different origin). On diagenesis scale, peat HAs have an intermediate position between the living organic matter and coal organic matter, and their structure is formed in a process in which more labile structures (carbohydrates, amino acids, etc.) are destroyed, while thermodynamically more stable aromatic and polyaromatic structures emerge as a result of abiotic synthesis. However, in comparison with soil, aquatic and other HAs, aromaticity of peat HAs is much lower. Comparatively, the raised bog peat HAs are at the beginning of the transformation process of living organic matter. Concentrations of carboxyl and phenolic hydroxyl groups change depending on the peat age and decomposition degree from where HAs have been isolated, and carboxylic acidity of peat HAs increases with peat depth and humification degree.

  9. 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.

  10. 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.

  11. Increased Electron-Accepting and Decreased Electron-Donating Capacities of Soil Humic Substances in Response to Increasing Temperature.

    Science.gov (United States)

    Tan, Wenbing; Xi, Beidou; Wang, Guoan; Jiang, Jie; He, Xiaosong; Mao, Xuhui; Gao, Rutai; Huang, Caihong; Zhang, Hui; Li, Dan; Jia, Yufu; Yuan, Ying; Zhao, Xinyu

    2017-03-21

    The electron transfer capacities (ETCs) of soil humic substances (HSs) are linked to the type and abundance of redox-active functional moieties in their structure. Natural temperature can affect the chemical structure of natural organic matter by regulating their oxidative transformation and degradation in soil. However, it is unclear if there is a direct correlation between ETC of soil HS and mean annual temperature. In this study, we assess the response of the electron-accepting and -donating capacities (EAC and EDC) of soil HSs to temperature by analyzing HSs extracted from soil set along glacial-interglacial cycles through loess-palaeosol sequences and along natural temperature gradients through latitude and altitude transects. We show that the EAC and EDC of soil HSs increase and decrease, respectively, with increasing temperature. Increased temperature facilitates the prevalence of oxidative degradation and transformation of HS in soils, thus potentially promoting the preferentially oxidative degradation of phenol moieties of HS or the oxidative transformation of electron-donating phenol moieties to electron-accepting quinone moieties in the HS structure. Consequently, the EAC and EDC of HSs in soil increase and decrease, respectively. The results of this study could help to understand biogeochemical processes, wherein the redox functionality of soil organic matter is involved in the context of increasing temperature.

  12. THE EFFECT OF FORMULATION HUMIC SUBSTANCE AND Trichoderma sp TO INCREASE PRODUCTION AND GROWTH OF CORN (Zea Mays,L

    Directory of Open Access Journals (Sweden)

    Ruly Eko Kusuma Kurniawan

    2017-06-01

    Full Text Available Research to determine of formulation humic subtance and Trichoderma sp to increase the production and growth of corn (zea mays,L. This research was conducted by extracting humic substance with fractionation organic matter method from cattle manure organic material. Trichoderma sp grow on corn medium and harvested after reaching a density of 1015 cfu. Created this compound formulation with mixing humic substance and Trichoderma sp. Indicator plant with F1 sweet corn Jago varieties. Aplication used humic substance in range 8%, 16%, and 32% on the recommended use NPK fertilizer for corn, as well as control without humic substance. The result showed application use 8% humic substance most good for plant growth and harvest. Additionally, nutrient uptake NPK fertilizer efficiency is increased and more effective than control and use of the formulation 16% and 32% humic substance.

  13. Peat humic acids and their complex forming properties as influenced by peat humification

    Science.gov (United States)

    Dudare, D.; Klavins, M.

    2012-04-01

    To study paleoenvironmental changes of importance is understanding of processes of organic matter diagenesis, especially changes of refractory part of natural organic substances - humic substances. Studies of the living organic matter humification process are also essential for understanding of the carbon biogeochemical cycle. The aim of this study was to analyze peat organic matter diagenesis: changes of properties of humic acids, relations between the humification process, properties of peat, peat humic acids, their ability to interact with metal ions, as well ability to accumulate metals. The analysis were carried out on samples of humic substances preparatively extracted from three ombrotrophic bog peat profiles to identify the links between peat age, decomposition and humification degree, botanical composition and properties of peat humic acids elemental (C, H, N, O), functional (-COOH, -OH) composition, structural characteristics - UV, fluorescence, FTIR. The found variability of peat properties is less significant than differences in the properties of peat-forming living matter, thus revealing the dominant impact of humification process on the properties of peat. Correspondingly, composition of peat humic acids is little affected by differences in the properties of precursor living organic material, and such indicators as decomposition degree, humification degree, humic acid elemental ratio and concentrations of acidic functional groups are the best descriptors of changes in organic matter during the process of organic matter diagenesis and humification. Peat ability to accumulate major and trace elements depends on the character of element supply, potency of metal ions to bind functionalities in the peat, with an emphasis on the structure of peat humic acid, pH reaction, oxygen presence, presence of complexing compounds, inorganic ions and many other factors. Major and trace element presence in peat is of importance as an indicator of peat genesis and

  14. ACCELERATION ON THE GROWTH OF RUBBER PLANTING MATERIALS BY USING FOLIAR APPLICATION OF HUMIC ACID

    Directory of Open Access Journals (Sweden)

    Andi Nur Cahyo

    2014-06-01

    Full Text Available The best rubber planting materials are needed to build the best rubber plantation. Humic acids could be used to improve the growth of rubber planting materials. Humic acid plays a role as a hormone-like substance. This research was aimed to determine the optimal concentration of foliar application of humic acid in order to enhance the growth of rubber tree planting materials. This research was arranged in a completely randomized block design with five treatments and four replicates. The treatments were the concentrations of humic acids, i. e. 0; 250; 500; 750; and 1,000 ppm. Observations were made on rubber tree diameter, plant height, shoot and root biomass, and nutrient content of leaves and the stem. The results showed that foliar application of 1,000 ppm of humic acids could enhance the growth of rubber tree planting materials. Foliar application of 500 – 1,000 ppm of humic acids could increase K content of the stem. The effects of foliar application of humic acids were more apparent in the root part than in the shoot part.

  15. Determination of humic acid in alkali leaching solution of uranium by spectophotrometry-COD method

    International Nuclear Information System (INIS)

    Feng Yu; An Wei; Chen Shusen

    2014-01-01

    It is one of the main causes of extraction emulsification or resin toxicosis during alkali leaching process in uranium metallurgy which organic matters including humic acid exist in lixiviums. In order to study the effect of humic acid in uranium metallurgy, a method for determination of content of humic acid in aqueous solution need to be established. Spectrophotometry is a simple and convenient method in humic acid analysis. However, accuracy of spectrophotometry can be reduced greatly because of interference of uranium and other elements in the humic acid solutions. Although chemical oxygen demand (COD) method is a common analysis way of organic matters in aqueous solutions, the concentration of humic acid cannot be directly measured. In this paper, COD method is related with spectrophotometry to avoid the interference of uranium and ensure the accurate analysis of humic acid. The results showed that the detection limit of the method was 1.78 mg/L and the recovery rate was 101.2%. (authors)

  16. Humic acids: Their detergent qualities and potential uses in pollution remediation

    Directory of Open Access Journals (Sweden)

    von Wandruszka Ray

    2000-04-01

    Full Text Available Humic acids are amphiphilic species whose behavior in aqueous solution suggests that they form pseudomicelles–aggregates akin to the micelles familiar from synthetic surfactant chemistry. It is thought that humic pseudomicelles can be formed by both intramolecular coiling and intermolecular association, depending on the molecular weight, structural characteristics, and polydispersity of the humic acid in question. The process does not feature a critical micelle concentration. Experimental evidence indicates that metal ions enhance the detergent character of dissolved humic acid by facilitating the coiling and folding of the polymer chains. A recently conceived alternative model suggests that humic acids consist of relatively small subunits that associate through weak molecular interactions. This view appears to run counter to certain experimental observations, but deserves careful attention. The strong association between metal ions and solid humic acid makes it possible to use an inexpensive commercial grade for the decontamination of polluted water. A continuous elution process through a column packed with humic acid allows for the removal of both heavy metals and organic xenobiotics from aqueous solution.

  17. Mitigation of Humic Acid Inhibition in Anaerobic Digestion of Cellulose by Addition of Various Salts

    Directory of Open Access Journals (Sweden)

    Samet Azman

    2015-03-01

    Full Text Available Humic compounds are inhibitory to the anaerobic hydrolysis of cellulosic biomass. In this study, the impact of salt addition to mitigate the inhibitory effects of humic compounds was investigated. The experiment was conducted using batch tests to monitor the anaerobic hydrolysis of cellulose in the presence of humic acid. Sodium, potassium, calcium, magnesium and iron salts were tested separately for their efficiency to mitigate humic acid inhibition. All experiments were done under mesophilic conditions (30 °C and at pH 7. Methane production was monitored online, using the Automatic Methane Potential Test System. Methane production, soluble chemical oxygen demand and volatile fatty acid content of the samples were measured to calculate the hydrolysis efficiencies. Addition of magnesium, calcium and iron salts clearly mitigated the inhibitory effects of humic acid and hydrolysis efficiencies reached up to 75%, 65% and 72%, respectively, which were similar to control experiments. Conversely, potassium and sodium salts addition did not mitigate the inhibition and hydrolysis efficiencies were found to be less than 40%. Mitigation of humic acid inhibition via salt addition was also validated by inductively coupled plasma atomic emission spectroscopy analyses, which showed the binding capacity of different cations to humic acid.

  18. Effect of Humic Acid on some Agronomic Characters of some Varieties of Alfalfa (Medicago sativa L.

    Directory of Open Access Journals (Sweden)

    Ali Tadayyon

    2016-10-01

    Full Text Available To evaluate the effect of humic acid on some cultural characters of some alfalfa varieties, a field experiment was conducted as factorial split plot based on RCBD design with three replications in 2014. In this experiment, 5 varieties of alfalfa (Yazdi, Hamedani, Baghdadi, Bami and Ranger and three levels of humic acid (5 and 10 lha-1 and without humic acid, as control were considered as the first factor and harvest time was as the second factor. Result indicated that except plant height, other characteristics such as dry weight yield, dry weight per plant, root and shoot dry weight per plant, number of leaves and stem diameter were affected by triple interaction effect of harvest time×variety×humic acid. Plant height was affected by double interaction effect of variety×humic acid and also harvest time×variety. Yazdi and Bami had the highest and Ranger had the least values of traits under study in two cuttings, respectively. Also in the between of humic acid treatments, 10 lha-1 treatment produced highest traits measured as compared to control and 5 lha-1 treatment. Bami, Ranger and Yazdi varieties with 10 lha-1of humic acid in two cuttings produced the highest dry weight yield (3.64, 3.55 and 3.26 t.ha-1 respectively in this experiment.

  19. Effects of humic acid on adsorption of actinide elements on rocks and others

    Energy Technology Data Exchange (ETDEWEB)

    Ohashi, Masakazu; Sato, Seichi; Ohashi, Hiroshi [Hokkaido Univ., Sapporo (Japan). Faculty of Engineering; Sakamoto, Yoshiaki; Nagao, Seiya; Onuki, Toshihiko; Senoo, Muneaki

    1996-01-01

    Since the transfer rates of radionuclides are reduced by their adsorption to rocks and soils, it is essential to elucidate the adsorption process for safety assessment of their geological disposal. In this study, adsorption of Np(V) to goethite, one of the widely distributed minerals was investigated as functions of pH and humic acid concentration. The surface charge density of goethite was determined and the zero charge point was 6.2 for synthesized and 6.4 for natural goethite. Since the point for humic acid was 4.5, adsorption sites for humic acid were reduced as the increase of negative charge density above pH6, resulting in a decrease in its adsorption rate. Np(V) adsorption to goethite was raised by the presence of humic acid in the range of 0-10ppm because the surface charge on the rock was shifted to negative by the adsorption of humic acid, resulting in easy adsorption of NpO{sub 2}{sup +}, which is stable in the condition below pH 9.5. On the other hand, humic acid adsorption was saturated at a concentration higher than 50 ppm, but its content in the solution would increase. Thus, it was thought that Np(V)-humic acid complex becomes more stable, resulting in the decrease in Np(V) adsorption rate. (M.N.)

  20. Stabilization of polynuclear plutonium(IV) species by humic acid

    Science.gov (United States)

    Marsac, Rémi; Banik, Nidhu Lal; Marquardt, Christian Michael; Kratz, Jens Volker

    2014-04-01

    Although the formation of tetravalent plutonium (Pu(IV)) polymers with natural organic matter was previously observed by spectroscopy, there is no quantitative evidence of such reaction in batch experiments. In the present study, Pu(IV) interaction with humic acid (HA) was investigated at pH 1.8, 2.5 and 3, as a function of HA concentration and for Pu total concentration equal to 6 × 10-8 M. The finally measured Pu(IV) concentrations ([Pu(IV)]eq) are below Pu(IV) solubility limit. Pu(IV)-HA interaction can be explained by the complexation of Pu(IV) monomers by HA up to [Pu(IV)]eq ∼ 10-8 M. However, the slope of the log-log Pu(IV)-HA binding isotherm changes from ∼0.7 to ∼3.5 for higher [Pu(IV)]eq than ∼10-8 M and at any pH. This result suggests the stabilization of hydrolyzed polymeric Pu(IV) species by HA, with a 4:1 Pu:HA stoichiometry. This confirms, for the first time, previous observations made by spectroscopy in concentrated systems. The humic-ion binding model, Model VII, was introduced into the geochemical speciation program PHREEQC and was used to simulate Pu(IV) monomers binding to HA. The simulations are consistent with other tetravalent actinides-HA binding data from literature. The stabilization of a Pu tetramer (Pu4(OH)88+) by HA was proposed to illustrate the present experimental results for [Pu(IV)]eq > 10-8 M. Predictive simulations of Pu(IV) apparent solubility due to HA show that the chosen Pu(IV)-polymer has no impact for pH > 4. However, the comparison between these predictions and recent spectroscopic results suggest that more hydrolyzed polymeric Pu(IV) species can be stabilized by HA at pH > 4. Polymeric Pu(IV)-HA species might significantly enhance Pu(IV) apparent solubility due to humics, which support a colloid-facilitated transport of this low solubility element.

  1. Pyrolysis-mass spectrometry/pattern recognition on a well-characterized suite of humic samples

    Science.gov (United States)

    MacCarthy, P.; DeLuca, S.J.; Voorhees, K.J.; Malcolm, R.L.; Thurman, E.M.

    1985-01-01

    A suite of well-characterized humic and fulvic acids of freshwater, soil and plant origin was subjected to pyrolysis-mass spectrometry and the resulting data were analyzed by pattern recognition and factor analysis. A factor analysis plot of the data shows that the humic acids and fulvic acids can be segregated into two distinct classes. Carbohydrate and phenolic components are more pronounced in the pyrolysis products of the fulvic acids, and saturated and unsaturated hydrocarbons contribute more to the humic acid pyrolysis products. A second factor analysis plot shows a separation which appears to be based primarily on whether the samples are of aquatic or soil origin. ?? 1985.

  2. Оptimization of humic acids extraction from coal of Oy-karagay field

    Directory of Open Access Journals (Sweden)

    Zhaksyntay Kairbekov

    2012-12-01

    Full Text Available Optimum conditions of extraction of humic acids from brown coal of a domestic Oy-Karagay field using the  method of experiment planning were defined: extraction temperature – 80 оC; duration of experiment – 45 minutes; concentration of alkali – 1,0 %; ratio of coal and alkali solution equal 1:25. The experiment realized in these conditions is coordinated with sampled data. The  composition of the humic acids extracted after alkaline processing of brown coal have been  investigated by  IR-spectroscopy. IR spectrum of humic acids contains a band due to the active acidic groups.

  3. 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

  4. Interaction between pesticides and humic substances from tropical coastal lagoons

    International Nuclear Information System (INIS)

    Gonzalez-Farias, F.; Carvalho, F.P.; Fowler, S.W.; Cotret, O.

    1999-01-01

    The HS that enter the lagoons with freshwater runoff tend to precipitate with salinity. Experiments were done in laboratory to determine the effect of HS (isolated from coastal lagoons) and humic acids (HA) (Aldrich) on the partition of selected pesticides between water and sediment phases. Due to the accurate results obtained with radio-labelled compounds, 14 C-labelled pesticides were used for the experiments. The selected pesticides were: chlorpyrifos (o,o-di-[1- 14 C]ethyl o-3,5,6-trichloro-2-pyridil phosphorotioate), DDT (1,1,1-trichloro-2,2-bis(p-chloro-[ring-U- 14 C]-phenyl)ethane) and parathion (o,o-diethyl o-4-nitro-[ring-U- 14 C]-phenyl phosphorotioate)

  5. A new technique for tritium labeling of humic substances

    Energy Technology Data Exchange (ETDEWEB)

    Badun, G.A.; Chernysheva, M.G.; Tyasto, Z.A. [Lomonosov Moscow State University, Moscow (Russian Federation). Radiochemistry Division, Chemistry Department; Kulikova, N.A. [Lomonosov Moscow State University, Moscow (Russian Federation). Department of Soils; Kudryavtsev, A.V.; Perminova, I.V. [Lomonosov Moscow State University, Moscow (Russian Federation). Organic Chemistry Division, Chemistry Department

    2010-07-01

    Humic substances (HS) of different origins have been labeled with tritium by the thermal activation method. Specific radioactivity of labeled HS ({sup 3}H-HS) was sufficiently high and varied from 0.14 to 0.6 TBq/g. Parent HS and {sup 3}H-HS were analyzed by size exclusion chromatography with radioactivity and UV detection. The results allowed concluding that (1) neither partial decomposition nor polymerization of HS occurred during labeling and (2) tritium labeled molecules have a regular distribution among HS fractions of different molecular weights. The performed correlation analysis revealed that there was no significant relationship between HS properties and specific radioactivity of the obtained {sup 3}H-HS. Thus universality of the developed technique for radioactive labeling of HS with tritium could be demonstrated. (orig.)

  6. Removal of humic substances for coagulation with Alum

    International Nuclear Information System (INIS)

    Camargo Valero, Miller; Cruz Torres, Luis Eduardo

    1999-01-01

    In the search of better conditions to remove precursory material in the formation of disinfections sub-products with free chlorine, was found that the absorbance to the ultraviolet to 254 nm (AUV 254 nm) it is a parameter that can be used as non-specific measure, to estimate concentrations of precursory material, specifically humic substances, and also, like control instrument in the operations and previous processes to the disinfections with free chlorine. The study tries the importance so that in the handling essays of potable water is included the AUV 254 nm like control parameter. In essays of coagulation with alum was found that the removal of these substances depends on the dose of coagulation and the pH of coagulation

  7. 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.

  8. Interaction between uranium and humic acid (II): complexation, precipitation and migration behavior of U(VI) in the presence of humic substances

    International Nuclear Information System (INIS)

    Liao Jiali; Li Bing; Yang Yuanyou; Jin Jiannan; Liu Ning; Wen Wei; Zhang Dong; Kang Houjun; Yang Yong

    2013-01-01

    The complexation, precipitation, and migration behavior of uranium in the presence of humic acid (HA) or fulvic acid (FA) were investigated by cation exchange, ultrafiltration and dynamic experiment, respectively. The results showed that (i) complex equilibrium between the uranium and humic substances was achieved at approximately 72 h, (ii) the coordination number varied from 1:1 to 1:2 (U(VI): humic acid) as pH increased from 3 to 6; and (iii), while the complex stability constant decreased when temperature increased, but increased with pH value. We found that the precipitation of uranyl could only be observed in presence of HA, and the precipitation was influenced by conditions, such as pH, uranium concentration, temperature, and the HA concentration. The maximum precipitation proportion up to 60% could be achieved in the condition of 40 mg/L HA solution at pH 6. We further observed that the migration behavior of uranium in soil in the presence of humic acid (HA) or fulvic acid (FA) was different from that in the presence of inorganic colloid, and the effect of humic substances (HS) was limited. (authors)

  9. Electrocoagulation treatment of peat bog drainage water containing humic substances.

    Science.gov (United States)

    Kuokkanen, V; Kuokkanen, T; Rämö, J; Lassi, U

    2015-08-01

    Electrocoagulation (EC) treatment of 100 mg/L synthetic wastewater (SWW) containing humic acids was optimized (achieving 90% CODMn and 80% DOC removal efficiencies), after which real peat bog drainage waters (PBDWs) from three northern Finnish peat bogs were also treated. High pollutant removal efficiencies were achieved: Ptot, TS, and color could be removed completely, while Ntot, CODMn, and DOC/TOC removal efficiencies were in the range of 33-41%, 75-90%, and 62-75%, respectively. Al and Fe performed similarly as the anode material. Large scale experiments (1 m(3)) using cold (T = 10-11 °C) PBDWs were also conducted successfully, with optimal treatment times of 60-120 min (applying current densities of 60-75 A/m(2)). Residual values of Al and Fe (complete removal) were lower than their initial values in the EC-treated PBDWs. Electricity consumption and operational costs in optimum conditions were found to be low and similar for all the waters studied: 0.94 kWh/m(3) and 0.15 €/m(3) for SWW and 0.35-0.70 kWh/m(3) and 0.06-0.12 €/m(3) for the PBDWs (large-scale). Thus, e.g. solar cells could be considered as a power source for this EC application. In conclusion, EC treatment of PBDW containing humic substances was shown to be feasible. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Photocatalytic degradation of Congo Red by hydrothermally synthesized nanocrystalline TiO2 and identification of degradation products by LC-MS

    International Nuclear Information System (INIS)

    Erdemoglu, Sema; Aksu, Songuel Karaaslan; Sayilkan, Funda; Izgi, Belgin; Asiltuerk, Meltem; Sayilkan, Hikmet; Frimmel, Fritz; Guecer, Seref

    2008-01-01

    Degradation of Congo Red (CR) dye in aqueous solutions was investigated by means of photocatalysis of TiO 2 which was hydrothermally synthesized at 200 deg. C in 2 h, in anatase phase with 8 nm crystallite size. Efficiency of TiO 2 in photocatalytic degradation under visible irradiation was studied by investigating the effects of amount of TiO 2 , irradiation time, initial CR concentration and pH. It was found that complete decolorization is achieved within 30 min of irradiation. Effects of nitrate and sulphate ions and humic acid on the degradation were also tested. The results were compared with Degussa P-25 TiO 2 at the same degradation conditions. Degradation products were detected using LC-MS technique. The probable pathways for the formation of degradation products were proposed

  11. Improvement of Sweet Potato Production as Affected by Potassium and Humic Acids Using 15N Isotopic Dilution Technique

    International Nuclear Information System (INIS)

    Soliman, M.S.; Abdel Aziz, H.A.; Moursy, A.A.

    2014-01-01

    Field experiment was conducted to trace the effects of potassium fertilizer and different levels of humic acid on yield production of sweet potato grown on sandy soil under drip irrigation system. Different characteristics of sweet potato growth i.e. vegetative parameter (Vine, tuber dry matter yield) and quality of tuber constitutes (nutrients uptake) were determined. Results showed that application of 100% potassium fertilizer with humic 2 (contented 70% Humic and 15% Fulvic) induced higher tuber yield than 50% potassium fertilizer and unfertilized treatment. The most effective treatments (H 2 , H 3 and H 0 ) under 100% potassium fertilizer reflected higher tuber dry weight as compared to unfertilized treatment (1.3 kg plot -1 ).The addition of humic 2 had increased N uptake by tuber over those recorded with the other treatments. In this regards, humic 2 , humic 3 , humic 1 and humic 0 accumulated 27.7, 23.4, 19.8g N plot -1 , respectively against 18.4 g N plot -1 for control. Under rate of 100% potassium fertilizer, the effect of humic treatments on N uptake by vine could be arranged as following: H 3 > H 1 > H 2 > H 0 . Potassium uptake by tuber has the same trend where H 2 resulted is the best value among the other humic treatments. It seems that N content of tuber was lower than those of vine. Reversible trend was noticed with K uptake where its content in tuber was higher than vine. This holds true with all humic and non-humic treatments. In general, the percentage fertilizer use efficiency (%FUE) was enhanced by application of humic acid with varying extent

  12. Evaluation of humic fractions potential to produce bio-oil through catalytic hydroliquefaction.

    Science.gov (United States)

    Lemée, L; Pinard, L; Beauchet, R; Kpogbemabou, D

    2013-12-01

    Humic substances were extracted from biodegraded lignocellulosic biomass (LCBb) and submitted to catalytic hydroliquefaction. The resulting bio-oils were compared with those of the initial biomass. Compared to fulvic and humic acids, humin presented a high conversion rate (74 wt.%) and the highest amount of liquid fraction (66 wt.%). Moreover it represented 78% of LCBb. Humin produced 43 wt.% of crude oil and 33 wt.% of hexane soluble fraction containing hydrocarbons which is a higher yield than those from other humic substances as well as from the initial biomass. Hydrocarbons were mainly aromatics, but humin produces the highest amount of aliphatics. Considering the quantity, the quality and the molecular composition of the humic fractions, a classification of the potential of the latter to produce fuel using hydroliquefaction process can be assess: Hu>AF>AH. The higher heating value (HHV) and oxygen content of HSF from humin were fully compatible with biofuel characteristics. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. A study of the chemical composition of peat humic acids by adsorption liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Platonov, V.V.; Proskuryakov, V.A.; Surasinkha, S.; Platonova, M.V.; Taran, N.A. [Lev Tolstoi State Pedagogical University, Tula (Russian Federation)

    1998-12-01

    The chemical composition of peat humic acids was studied in detail by IR and UV spectroscopy, elemental, emission spectral X-ray fluorescence, and structural-group analyses, cryoscopy, and capillary gas chromatography.

  14. Photodegradation of bisphenol A in simulated lake water containing algae, humic acid and ferric ions

    International Nuclear Information System (INIS)

    Peng Zhang'e; Wu Feng; Deng Nansheng

    2006-01-01

    The photodegradation of bisphenol A (BPA), a suspected endocrine disruptor (ED), in simulated lake water containing algae, humic acid and Fe 3+ ions was investigated. Algae, humic acid and Fe 3+ ions enhanced the photodegradation of BPA. Photodegradation efficiency of BPA was 36% after 4 h irradiation in the presence of 6.5 x 10 9 cells L -1 raw Chlorella vulgaris, 4 mg L -1 humic acid and 20 μmol L -1 Fe 3+ . The photodegradation efficiency of BPA was higher in the presence of algae treated with ultrasonic than that without ultrasonic. The photodegradation efficiency of BPA in the water only containing algae treated with ultrasonic was 37% after 4 h irradiation. The algae treated with heating can also enhance the photodegradation of BPA. This work helps environmental scientists to understand the photochemical behavior of BPA in lake water. - Algae, humic acid and ferric ions can induce the photodegradation of bisphenol A in an aqueous environment

  15. Characterization of the coal derived humic acids from Mukah, Sarawak as soil conditioner

    Directory of Open Access Journals (Sweden)

    Fong Sim Siong

    2006-01-01

    Full Text Available In Malaysia, abundant coal resources were found in Sarawak and Sabah. The utilization of coal resources, to date, is emphasized on the energy productions. The non-energy utilization as soil conditioner is unexplored. Therefore, this study attempted to characterize the coal humic acids extracted from Mukah coal and to evaluate its properties as soil conditioner. The coal humic acids from the regenerated sample were also assessed. The results revealed that different extractants and concentrations influenced the properties of humic acids. The extraction with KOH at 0.5 mol L-1 produced humic acids with low ash content and high acidic functional groups, which are substantial as soil conditioner. However, the yield was low. Regeneration of coal sample with 10% nitric acids improved the yield to an average of 83.45%. The acidic functional groups of nitrohumic acids were improved with the ash content remained at a low level.

  16. Assessing the Effect of Humic Acids on Germinating a Native American Plant

    National Research Council Canada - National Science Library

    Nicola, Senesi

    2004-01-01

    ... (HAs) in Idaho soils on seed germination and seedling early-growth of slickspot peppergrass, and their possible relations to the compositional, structural and functional characteristics of humic acids...

  17. 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.

    Interactions of mercury (Hg) with different molecular weight fractions of humic substances (HS) play an important role in controlling distribution, diffusion, speciation, and bioavailability of Hg in natural systems. This study suggests that Hg...

  18. Humic acids enhance the microbially mediated release of sedimentary ferrous iron.

    Science.gov (United States)

    Chang, Chun-Han; Wei, Chia-Cheng; Lin, Li-Hung; Tu, Tzu-Hsuan; Liao, Vivian Hsiu-Chuan

    2016-03-01

    Iron (Fe) is an essential element for many organisms, but high concentrations of iron can be toxic. The complex relation between iron, arsenic (As), bacteria, and organic matter in sediments and groundwater is still an issue of environmental concern. The present study addresses the effects of humic acids and microorganisms on the mobilization of iron in sediments from an arsenic-affected area, and the microbial diversity was analyzed. The results showed that the addition of 50, 100, and 500 mg/L humic acids enhanced ferrous iron (Fe(II)) release in a time-dependent and dose-dependent fashion under anaerobic conditions. A significant increase in the soluble Fe(II) concentrations occurred in the aqueous phases of the samples during the first 2 weeks, and aqueous Fe(II) reached its maximum concentrations after 8 weeks at the following Fe(II) concentrations: 28.95 ± 1.16 mg/L (original non-sterilized sediments), 32.50 ± 0.71 mg/L (50 mg/L humic acid-amended, non-sterilized sediments), 37.50 ± 1.85 mg/L (100 mg/L humic acid-amended, non-sterilized sediments), and 39.00 ± 0.43 mg/L (500 mg/L humic acid-amended, non-sterilized sediments). These results suggest that humic acids can further enhance the microbially mediated release of sedimentary iron under anaerobic conditions. By contrast, very insignificant amounts of iron release were observed from sterilized sediments (the abiotic controls), even with the supplementation of humic acids under anaerobic incubation. In addition, the As(III) release was increased from 50 ± 10 μg/L (original non-sterilized sediments) to 110 ± 45 μg/L (100 mg/L humic acid-amended, non-sterilized sediments) after 8 weeks of anaerobic incubation. Furthermore, a microbial community analysis indicated that the predominant class was changed from Alphaproteobacteria to Deltaproteobacteria, and clearly increased populations of Geobacter sp., Paludibacter sp., and Methylophaga sp. were found after adding humic acids

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

    Directory of Open Access Journals (Sweden)

    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.

  20. Proton resonance spectra of humic acids from the solum of a podzol

    International Nuclear Information System (INIS)

    Lentz, H.; Luedemann, H.-D.; Ziechmann, W.

    1977-01-01

    The proton resonance spectra at 100 MHz are reported for humic acids extracted from A and B horizons of an Erica Podzol at pH = 4.5, 7, and 14. The spectra were taken of 5% w/w solutions in 0.1 N sodium deuterooxide in heavy water. Differences between humic acids from the A and B horizons can be quantitatively measured by proton resonance spectra

  1. Effects of humic and fulvic acids on release of fixed potassium

    International Nuclear Information System (INIS)

    Tan, K.H.

    1978-01-01

    Release of potassium fixed by expanding silicate clays is considered of practical importance in soil fertility. Humic and fulvic acids are expected to play a definite role in liberating this fixed K, because of their chelating power, but not much is known in this respect. This investigation was conducted to study release of fixed K by montmorillonite and illite, using humic and fulvic acids isolated from the surface horizon of a Cecil soil (Typic Hapludult, Red Yellow Podzolic soil) as extractants. (Auth.)

  2. 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.

  3. 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....

  4. Identification of bound alcohols in soil humic acids by gas chromatography-mass spectrometry

    OpenAIRE

    Berthier , Gersende; Dou , Sen; Peakman , Torren; Lichtfouse , Eric

    2000-01-01

    International audience; Humic acids are complex, partly macromolecular, yellow-brownish substances occurring in soils, waters and sediments. In order to shed some light on their molecular structure, crop humic acids were cleaved by alkaline hydrolysis (KOH). The products were fractionated by thin layer chromatography to give mono-alcohols which were analysed as acetate derivatives by gas chromatography coupled to mass spectrometry. Linear alcohols, sterols, stanols and plant-derived triterpen...

  5. Mechanism of the toxicity induced by natural humic acid on human vascular endothelial cells

    OpenAIRE

    Kihara, Yusuke; Yustiawati; Tanaka, Masato; Gumiri, Sulmin; Ardianor; Hosokawa, Toshiyuki; Tanaka, Shunitz; Saito, Takeshi; Kurasaki, Masaaki

    2012-01-01

    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 c...

  6. Evaluation of NaOH leaching techniques to extract humic acids from palaeosols

    Energy Technology Data Exchange (ETDEWEB)

    Head, M.J. E-mail: john_head@uow.edu.au; Zhou, W.J

    2000-10-01

    It can be shown quite conclusively that the often used technique (AAA) of leaching palaeosol samples with hot or boiling dilute HCl solution, followed by treatment with up to 2% NaOH solution and a further treatment with dilute HCl solution may not remove all of the so-called humic acids from palaeosol samples. In fact, in many cases it does not remove any of the humic acids, only carbohydrates, amino acids and other organic compounds. This can be shown by examination of the visible spectrum (400-700 nm) of the 'humic acid' extract in alkaline solution. Hence, many of the reported {sup 14}C results from the 'humin' fraction of palaeosols are actually from the humic acid fraction which is tightly bound to the clay component of the palaeosol. The NaOH leach also has the potential to introduce carboxylic acid groups from atmospheric CO{sub 2} into phenol groups. A reevaluation of humic acid extracts of palaeosols collected from the Loess Plateau in China has been made, with analyses comparing the properties of the various organic extracts. Also, an extraction technique based on recommendations from the International Humic Substances Society, incorporating removal of impurities by chromatography plus a decarboxylation step is proposed.

  7. 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.

  8. 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.

  9. Transformation of Flame Retardant Tetrabromobisphenol A by Aqueous Chlorine and the Effect of Humic Acid.

    Science.gov (United States)

    Gao, Yuan; Pang, Su-Yan; Jiang, Jin; Ma, Jun; Zhou, Yang; Li, Juan; Wang, Li-Hong; Lu, Xue-Ting; Yuan, Li-Peng

    2016-09-06

    In this work, it was found that the most widely used brominated flame retardant tetrabromobisphenol A (TBrBPA) could be transformed by free chlorine over a wide pH range from 5 to 10 with apparent second-order rate constants from 138 to 3210 M(-1)·s(-1). A total of eight products, including one quinone-like compound (i.e., 2,6-dibromoquinone), two dimers, and several simple halogenated phenols (e.g., 4-(2-hydroxyisopropyl)-2,6-dibromophenol, 2,6-dibromohydroquinone, and 2,4,6-tribromophenol), were detected by high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) using a novel precursor ion scan (PIS) approach. A tentative reaction pathway was proposed: chlorine initially oxidized TBrBPA leading to the formation of a phenoxy radical, and then this primary radical and its secondary intermediates (e.g., 2,6-dibromo-4-isopropylphenol carbocation) formed via beta-scission subsequently underwent substitution, dimerization, and oxidation reactions. Humic acid (HA) considerably inhibited the degradation rates of TBrBPA by chlorine even accounting for oxidant consumption. A similar inhibitory effect of HA was also observed in permanganate and ferrate oxidation. This inhibitory effect was possibly attributed to the fact that HA competitively reacted with the phenoxy radical of TBrBPA and reversed it back to parent TBrBPA. This study confirms that chlorine can transform phenolic compounds (e.g., TBrBPA) via electron transfer rather than the well-documented electrophilic substitution, which also have implications on the formation pathway of halo-benzoquinones during chlorine disinfection. These findings can improve the understanding of chlorine chemistry in water and wastewater treatment.

  10. Cathode degradation

    Energy Technology Data Exchange (ETDEWEB)

    Shores, D.A.; Selman, J.R.; Ong, E.T.

    1989-12-01

    This report describes the results of a three-year study of cathode degradation in molten carbonate fuel cells involving both experimental and theoretical work. A keystone of the study is the development of a mathematical model, which describes cathode degradation in terms of the fundamental processes of a fluxing mechanism, i.e., dissolution, transport and precipitation. New fundamental data have been obtained on the solubility of NiO, especially on the effect of water vapor, and on the kinetics of NiO dissolution in (Li{sub 0.62}K{sub 0.38}){sub 2}CO{sub 3}, and these data have been incorporated in the model. Laboratory cell testing in 3 cm{sup 2} cells has been carried out to obtain experimental data on degradation rates for direct comparison with the calculated results from the model. These comparisons have helped to verify several aspects of the model. For example, the model predicts with fair accuracy the location of the Ni deposit in the tile and the deposition rate. It is also fair to point out that the model is a relatively simple representation of complex processes, and it does not answer all questions about cathode degradation. Further work is needed. Because of its fundamental basis, the model can readily be upgraded and extended when further experimental data become available. The solubility studies, modeling efforts and cell testing have interacted iteratively to optimize progress. 94 figs., 24 tabs.

  11. 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.

  12. Physiological effect of natural humic acid during pregnancy on fetuses and maternal alterations induced by irradiation in rats

    International Nuclear Information System (INIS)

    Abdel gawad, I.I.; Badar, H.M.; Shabon, M.H.

    2005-01-01

    Humic acid is a mixture of macromolecular heterogeneous substances which have high molecular weight. Humic acid is a soil constituent, playing an important role in forming and transferring the nutrients from the soil to the living organism to perform many physiological processes. Thus, the current study was performed to study the chemical characteristics of extracted humic acid (soil constituent in Egypt) and evaluate its physiological effects on irradiated pregnant rats and some maternal biochemical parameter humic acid extract was obtained from the fine fraction of Egyptian soil (undersize 12 mesh sieve). The chemical characters were evaluated by means of IR, ESR, elemental and chemical analyses. It was found to contain all functional groups characterize natural humic acids but it contains high concentration of free radicals (73 x 1018 spin /g). Humic acid was supplemented daily to rats at two separate doses (150 mg and 300 mg/kg) during the interval 1st to 13 th day of gestation. Irradiation (2.5 Gy) was applied one hour post the last dose of humic acid. Experimental investigations were performed on the day 21 of gestation. The results showed that supplementation of rats with humic acid at a dose of 150 mg/kg increased the number of fetuses and placental weight as well as fetal measurement. These morphological effects were paralleled with some biochemical effects in justifying the radioprotective potency of humic acid. Also, the humic acid given at the same dose improved the radiation induced disturbances in serum progesterone, calcium, phosphorus, calcitonin, total proteins and albumin levels whereas administration of humic acid at the high dose (300 mg/kg) induced harmful effect on most of the studied parameters and did not show any protective role against gamma irradiation. It could be concluded that administration of humic acid at the dose of 150 mg/kg during pregnancy of rats exerted a beneficial radioprotective effects on the tested physiological and

  13. 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

  14. Comparison between humic substances from soil and peats using TMAH and TEAAc thermochemolysis

    Energy Technology Data Exchange (ETDEWEB)

    Deport, C.; Lemee, L.; Ambles, A. [UMR-CNRS, Poitiers (France). Laboratoire de Synthese et Reactivite des Substances Naturelles

    2006-06-15

    Humic substances, mainly humic acids and humin, from a calcic peat (MP), an acid peat (CAL) and a calcic soil (MAT) were investigated. Important differences in the relative abundance of the various organic fractions were observed between the four samples. As shown by the HU/FA + HA ratio, the calcic peat contains the most humified organic matter, the degree of humification decreasing with pH. The organic matter in MAT was much less humified due to cultivation. Bulk information from spectroscopy showed similarities between the various humic acids and the various humins in the four samples: the presence of ester and ether groups, a marked aliphatic character and the presence of aromatic moieties. The major products of TMAH thermochemolysis were aromatic compounds derived from lignin, tannins and bark, and fatty acids of bacterial or plant origin, as the methyl esters (FAMEs). The compounds were mainly incorporated via ester or ether bonds and n-alkene/n-alkane doublets in the pyrolysate of CAL arose from resistant aliphatic biopolymers. The study of FAME distributions indicated that the bacterial contribution was higher in humic acids than in humin for all the samples. This contribution was much higher in MAT, as shown by prominent iso- and anteiso-C{sub 15} carboxylic acids and the presence of {alpha}-hydroxyacids. Bifunctional linear dicarboxylic acids were also incorporated into the humic structure (MAT and CAL), contributing to alkyl bridges. The C{sub 21}-C{sub 33} n-alkanes with a Gaussian distribution found in MAT and MP samples were initially retained in the humic structure via non-covalent bonds. TEAAc thermochemolysis showed that a fraction of the aliphatic acids (with a different distribution) was not covalently bound, having been sterically trapped in the humic structure. Trapped fatty acid methyl esters were minor. (author)

  15. Phytoremediation of Cu and Zn by vetiver grass in mine soils amended with humic acids.

    Science.gov (United States)

    Vargas, Carmen; Pérez-Esteban, Javier; Escolástico, Consuelo; Masaguer, Alberto; Moliner, Ana

    2016-07-01

    Phytoremediation of contaminated mine soils requires the use of fast-growing, deep-rooted, high-biomass, and metal-tolerant plants with the application of soil amendments that promote metal uptake by plants. A pot experiment was performed to evaluate the combined use of vetiver grass (Chrysopogon zizanioides) and humic acid for phytoremediation of Cu and Zn in mine soils. Vetiver plants were grown in soil samples collected from two mine sites of Spain mixed with a commercial humic acid derived from leonardite at doses of 0, 2, 10, and 20 g kg(-1). Plant metal concentrations and biomass were measured and metal bioavailability in soils was determined by a low molecular weight organic acid extraction. Results showed that humic acid addition decreased organic acid-extractable metals in soil. Although this extraction method is used to estimate bioavailability of metals, it was not a good estimator under these conditions due to competition with the strong chelators in the added humic acid. High doses of humic acid also promoted root growth and increased Cu concentrations in plants due to formation of soluble metal-organic complexes, which enhanced removal of this metal from soil and its accumulation in roots. Although humic acid was not able to improve Zn uptake, it managed to reduce translocation of Zn and Cu to aerial parts of plants. Vetiver resulted unsuitable for phytoextraction, but our study showed that the combined use of this species with humic acid at 10-20 g kg(-1) could be an effective strategy for phytostabilization of mine soils.

  16. 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.

  17. Humic substances in natural waters and their complexation with trace metals and radionuclides: a review

    International Nuclear Information System (INIS)

    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

  18. 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.

  19. Effect of humic substances on phosphorus removal by struvite precipitation.

    Science.gov (United States)

    Zhou, Zhen; Hu, Dalong; Ren, Weichao; Zhao, Yuzeng; Jiang, Lu-Man; Wang, Luochun

    2015-12-01

    Humic substances (HS) are a major fraction of dissolved organic matters in wastewater. The effect of HS on phosphorus removal by struvite precipitation was investigated using synthetic wastewater under different initial pH values, Mg/P molar ratios and HS concentrations. The composition, morphology and thermal properties of harvested precipitates were analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM) and thermo-gravimetric analysis (TGA), respectively. It showed that inhibition effect of HS reached its maximum value of 48.9% at pH 8.0, and decreased to below 10% at pH>9.0. The increase of Mg/P ratio enhanced phosphorus removal efficiency, and thus reduced the influence of HS on struvite precipitation. At pH 9.0, the inhibitory effect of initial HS concentration matched the modified Monod model with half maximum inhibition concentration of 356mgL(-1), and 29% HS was removed in conjunction with struvite crystallisation. XRD analysis revealed that the crystal form of struvite precipitates was changed in the presence of HS. The morphology of harvested struvite was transformed from prismatic to pyramid owing to the coprecipitation of HS on crystal surface. TGA results revealed that the presence of HS could compromise struvite purity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Effect of humic acid (HA) on sulfonamide sorption by biochars

    International Nuclear Information System (INIS)

    Lian, Fei; Sun, Binbin; Chen, Xi; Zhu, Lingyan; Liu, Zhongqi; Xing, Baoshan

    2015-01-01

    Effect of quantity and fractionation of loaded humic acid (HA) on biochar sorption for sulfonamides was investigated. The HA was applied in two different modes, i.e. pre-coating and co-introduction with sorbate. In pre-coating mode, the polar fractions of HA tended to interact with low-temperature biochars via H-bonding, while the hydrophobic fractions were likely to be adsorbed by high-temperature biochars through hydrophobic and π-π interactions, leading to different composition and structure of the HA adlayers. The influences of HA fractionation on biochar sorption for sulfonamides varied significantly, depending on the nature of interaction between HA fraction and sorbate. Meanwhile, co-introduction of HA with sulfonamides revealed that the effect of HA on sulfonamide sorption was also dependent on HA concentration. These findings suggest that the amount and fractionation of adsorbed HA are tailored by the surface properties of underlying biochars, which differently affect the sorption for organic contaminants. - Highlights: • Effect of quantity and fractionation of coated HA on sorption of sulfonamides by BC was studied. • Fractionation of coated HA is tailored by surface properties of BC. • Roles of HA in BC sorption depend on interaction between HA adlayer and sorbate. • Roles of HA in sulfonamide sorption by BC also depend on HA aqueous concentration. - The quantity and fractionation of adsorbed HA play a major role in sulfonamide sorption by biochars

  1. Interaction of Cocos nucifera cream casein with humic acid suspensions.

    Science.gov (United States)

    Fatombi, J K; Aminou, T; Lartiges, B; Topanou, N; Josse, R G

    2012-01-01

    Two caseins labelled as CaSMG (casein without fats) and CaMG (casein with fats) were extracted from coconut cream. Both caseins were used as coagulants for the aggregation of humic acid (HA) particles in synthetic water at pH = 6 during the jar-test essays. The optimum dosage of CaMG or CaSMG and the residual turbidities of treated water obtained depend on the type of used casein (CaMG or CaSMG) and the concentration of particles in solution. The optimal doses of CaMG and CaSMG are respectively 280 and 180 mg/L for solution S(1) (HA aqueous solution at 15 mg/L), and then 340 and 240 mg/L for solution S(2) (HA aqueous solution at 25 mg/L). The residual turbidities of treated water are respectively 6.88 and 3.85 NTU for solution S(1) and 4.52 and 2.53 NTU for solution S(2). The collected sediment volumes are respectively 1.2 and 1.5 mL for solutions S(1) and S(2). The electrophoretic mobility measurement and transmission electron microscopy images of flocs formed during the flocculation essays suggest that both caseins operate through both mechanisms (charge neutralisation and bridging process mechanism), this last one seems to be predominant. The aggregates formed are the large clusters and result from adsorption of HA particles by the casein molecules.

  2. Photodegradation of chlorpyrifos with humic acid-bound suspended matter.

    Science.gov (United States)

    Amarathunga, A A D; Kazama, F

    2014-09-15

    Land exploitation in several developing countries, including tropical areas, has caused a rapid change of the landscape, from forest to farms. This has led to an increase of pesticide use and concentration of suspended matter in river waters, which may cause soil erosion of these areas. Humic acid (HA), one of the main components in the soil particulate organic matter, has a positive effect on the photodegradation of organic matter in water; however, the efficiency of HA-bound suspended matter (HABSM) for pesticide photodegradation is not known. The aim of this study is to clarify the effect of HABSM on the photodegradation of chlorpyrifos employed in artificial soil particulate covered with HA. Experiments were carried out in liquid HA phase, with/without HABSM phase and HABSM with additional LHA phase under light. The adsorption procedure of the pesticide on HABSM was also studied. Our results reveal that adsorption takes place within a short time period on HABSM and that photodegradation is successfully achieved. The additional LHA+HABSM phase have not demonstrated any significant effect of HA concentration to photodegradation of chlorpyrifos. For instance, when 2.0mg/L chlorpyrifos was used in the experiments, concentration reductions caused by adsorption, photodegradation under suspended matter and HABSM were found to be 19.3, 17.7, and 61.7% respectively. This finding suggests that HABSM can be considered as a potential catalyst for pesticide photodegradation under sunlight. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Kinetics of adsorption of uranium from seawater by humic acids

    International Nuclear Information System (INIS)

    Heitkamp, D.; Wagener, K.

    1990-01-01

    The kinetics of the adsorption of uranium from seawater by humic acids fixed onto a polymer matrix was measured in a fluidized bed as a function of the grain size of the adsorbent and the flow velocity of the seawater. The adsorption rate was found to be governed by the diffusion of the uranium ions through the hydrodynamic surface layer of the adsorbent which is always formed in laminar flows of liquids. The measured rate constants are interpreted in terms of effective diffusion coefficients of 3.6 x 10 -5 cm 2 /s for uranyl ions and 1.8 x 10 -5 cm 2 /s for tricarbonatouranate ions in the surface layer. As a consequence of this kinetic behavior, the geometry of the adsorbent as well as the velocity of the water flow are relevant parameters for the amount of adsorbent needed for a projected extraction rate. This conclusion applies to all adsorption processes where diffusion through the hydrodynamic layer is the rate-determining kinetic step

  4. Ultraviolet irradiated water containing humic substances inhibits bacterial metabolism

    International Nuclear Information System (INIS)

    Lund, V.; Hongve, D.

    1994-01-01

    Disinfection of drinking water by u.v. irradiation has been observed to reduce the biofilm formation in the pipes in a pilot plant. An apparently inhibitory effect that persists in the water after the u.v. treatment has been studied in the laboratory. Reduced numbers of viable bacteria and reduced bacterial metabolism were observed when irradiated waters were inoculated with fresh bacteria. Approximately 60% of the heterotrophic bacteria in the water samples were inactivated within a 1 h contact time with freshly u.v. disinfected water. The uptake rates of labelled tracer substances were significantly reduced when the bacteria were exposed to irradiated water. The inhibitory effect seems to last for at least 1 week. High concentrations of organic matter seem to counteract the inhibitory effect. No relationship was found between u.v. dose and effect within the dose range tested. The observed effects may be explained by the action of oxidizing reagents such as hydroxyl radicals, produced in photochemical reactions between u.v. irradiation and humic substances in the water. (author)

  5. Influence of humic acids on the migration behavior of radioactive and non-radioactive substances under conditions close to nature. Synthesis, radiometric determination of functional groups, complexation

    International Nuclear Information System (INIS)

    Pompe, S.; Bubner, M.; Schmeide, K.; Heise, K.H.; Bernhard, G.; Nitsche, H.

    2000-04-01

    The interaction behavior of humic acids with uranium(VI) and the influence of humic substances on the migration behavior of uranium was investigated. A main focus of this work was the synthesis of four different humic acid model substances and their characterization and comparison to the natural humic acid from Aldrich. A radiometric method for the determination of humic acid functional groups was applied in addition to conventional methods for the determination of the functionality of humic acids. The humic acid model substances show functional and structural properties comparable to natural humic acids. Modified humic acids with blocked phenolic OH were synthesized to determine the influence of phenolic OH groups on the complexation behavior of humic acids. A synthesis method for 14 C-labeled humic acids with high specific activity was developed. The complexation behavior of synthetic and natural humic acids with uranium(VI) was investigated by X-ray absorption spectroscopy, laser-induced fluorescence spectroscopy and FTIR spectroscopy. The synthetic model substances show an interaction behavior with uranium(VI) that is comparable to natural humic acids. This points to the fact that the synthetic humic acids simulate the functionality of their natural analogues very well. For the first time the influence of phenolic OH groups on the complexation behavior of humic acids was investigated by applying a modified humic acid with blocked phenolic OH groups. The formation of a uranyl hydroxy humate complex was identified by laserspectroscopic investigations of the complexation of Aldrich humic acid with uranium(VI) at pH7. The migration behavior of uranium in a sandy aquifer system rich in humic substances was investigated in column experiments. A part of uranium migrates non-retarded through the sediment, bound to humic colloids. The uranium migration behavior is strongly influenced by the kinetically controlled interaction processes of uranium with the humic colloids

  6. Humic substances can modulate the allelopathic potential of caffeic, ferulic, and salicylic acids for seedlings of lettuce (Lactuca sativa L.) and tomato (Lycopersicon esculentum Mill.).

    Science.gov (United States)

    Loffredo, Elisabetta; Monaci, Linda; Senesi, Nicola

    2005-11-30

    The capacity of a leonardite humic acid (LHA), a soil humic acid (SHA), and a soil fulvic acid (SFA) in modulating the allelopathic potential of caffeic acid (CA), ferulic acid (FA), and salicylic acid (SA) on seedlings of lettuce (Lactuca sativa L.) and tomato (Lycopersicon esculentum Mill.) was investigated. Lettuce showed a sensitivity greater than that of tomato to CA, FA, and SA phytotoxicity, which was significantly reduced or even suppressed in the presence of SHA or SFA, especially at the highest dose, but not LHA. In general, SFA was slightly more active than SHA, and the efficiency of the action depended on their concentration, the plant species and the organ examined, and the allelochemical. The daily measured residual concentration of CA and FA decreased drastically and that of SA slightly in the presence of germinating seeds of lettuce, which were thus able to absorb and/or enhance the degradation of CA and FA. The adsorption capacity of SHA for the three allelochemicals was small and decreased in the order FA > CA > SA, thus suggesting that adsorption could be a relevant mechanism, but not the only one, involved in the "antiallelopathic" action.

  7. 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.

  8. Effects of humic substances on the migration of radionuclides: Complexation of actinides with humic substances. (6th progress report, project summary). Period covered: January 1994 - July 1994

    International Nuclear Information System (INIS)

    Czerwinski, K.R.; Rhee, D.S.; Scherbaum, F.; Buckau, G.; Kim, J.I.; Moulin, V.; Tits, J.; Laszak, I.; Moulin, C.; Decambox, P.; Ruty, O. de; Marquardt, C.; Franz, C.; Herrmann, G.; Trautmann, N.; Dierckx, A.; Vancluysen, J.; Maes, A.; Bidoglio, G.; Eliet, V.; Grenthe, I.

    1995-03-01

    The goal of the research project is to examine the complexation behaviour of actinide ions with humic substances and thermodynamically describe the binding based upon a simple complexation model. This program is a continuation of the activities of the colloid and complexation group (COCO) in the second phase of the EC-MIRAGE project. A number of different experimental methods are used to determine speciation. The metal ions examined are the trivalent lanthanides, UO 2 2+ , NpO 2 + , Am 3+ , and Cm 3+ . The project is divided into three tasks: Task 1: complexation reactions of actinide ions with well characterized reference and site-specific humic and fulvic acids, Task 2: complexation reactions with major cations in natural groundwaters; Task 3: validation of the complexation data in natural aquatic systems by comparison of calculation with spectroscopic experiment. Five European community laboratories participated in the program: Technische Universitaet Muenchen, Commissariat a l'Energie Atomique Fontenay-Aux-Roses and Saclay, Universitaet Mainz, Katolieke Universiteit Leuven, and Joint Research Centre, Ispra. The evaluated stability constants are similar for all laboratories when the same humic substance complexation model is applied. Humic acid is shown to reduce NpO 2 + to Np 4+ , while no reduction of UO 2 2+ is observed. Temperature effects are seen on the Np humate complex. Competition is observed between NpO 2 + and Ca 2+ , but not between the trivalent lanthanides and Ca 2+ . No influence of humic acid purification on the evaluated stability constants is seen. Using the evaluated constants, calculations are conducted for natural water systems which indicate the trivalent actinide humate complex to be an important species. (orig.)

  9. Humic substances in the Suwannee River, Georgia; interactions, properties, and proposed structures

    Science.gov (United States)

    Averett, R.C.; Leenheer, J.A.; McKnight, Diane M.; Thorn, K.A.

    1989-01-01

    Humic substances as a collective term and humic and fulvic acids as specific terms are not household words. For about a century, these terms belonged to the domain of the soil scientist. Even^though their chemical structures remained elusive, they were recognized as important entities in soil. During the past decade or so, there has been a renewed interest in humic substances in soil and water. Such interest has been the result of improved analytical instrumentation, and by a need to understand the structure and function of natural organic substances in water.A responsibility of the U.S. Geological Survey is to assess the Nation's water resources; this includes water quality, which is the study of material in water. Such material may be suspended, colloidal, or in true solution. Because humic substances are a major carbon source in water, they have received attention by Geological Survey scientists. This attention has been a major focus by members of the Geological Survey's organic-chemistry group. For more than a decade, this group has collected samples, made analyses, and worked toward determining the structures and function of humic substances in water. Their work has brought worldwide recognition to the field, and in 1981, through Geological Survey support, they helped organize the International Humic Substances Society, which held its first meeting in Estes Park, Colorado, in August 1983.At the second meeting of the Society in Birmingham, England, in August 1984, it became apparent that Geological Survey scientists were rapidly advancing the study of the chemistry of humic substances. It seemed appropriate, therefore, to publish this Open-File report on humic and fulvic acids from the Suwannee River in Georgia. The results represent our most definitive findings to date (1986). Though this work is not conclusive, it is state-of-the-science. Hopefully, our reporting on this work will aid in moving the science of humic substances forward as others read of our

  10. An estimation of influence of humic acid and organic matter originated from bentonite on samarium solubility

    International Nuclear Information System (INIS)

    Kanaji, Mariko; Sato, Haruo; Sasahira, Akira

    1999-10-01

    Organic acids in groundwater are considered to form complexes and increase the solubility of radionuclides released from vitrified waste in a high-level radioactive waste (HLW) repository. To investigate whether the solubility of samarium (Sm) is influenced by organic substances, we measured Sm solubility in the presence of different organic substances and compared those values with results from thermodynamic predictions. Humic acid (Aldrich) is commercially available and soluble organic matter originated from bentonite were used as organic substances in this study. Consequently, the solubility of Sm showed a tendency to apparently increase with increasing the concentration of humic acid, but in the presence of carbonate, thermodynamic predictions suggested that the dominant species are carbonate complexes and that the effect of organic substances are less than that of carbonate. Based on total organic carbon (TOC), the increase of Sm solubility measured with humic acid (Aldrich) was more significant than that in the case with soluble organic matter originated from bentonite. Since bentonite is presumed to include also simple organic matters of which stability constant for forming complexes is low, the effect of soluble organic matter originated from bentonite on the solubility of Sm is considered to be less effective than that of humic acid (Aldrich). Experimental values were compared with model prediction, proposed by Kim, based on data measured in a low pH region. Tentatively we calculated the increase in Sm solubility assuming complexation with humic acid. Trial calculations were carried out on the premise that the complexation reaction of metal ion with humic acid is based on neutralization process by 1-1 complexation. In this process, it was assumed that one metal ion coordinates with one unit of complexation sites which number of proton exchange sites is equal to ionic charge. Consequently, Kim's model indicated that carbonate complexes should be dominant

  11. Perspectives of humic substances application in remediation of highly heavy metals contaminated soils in Kola Subarctic

    Science.gov (United States)

    Tregubova, Polina; Turbaevskaya, Valeria; Zakharenko, Andrey; Kadulin, Maksim; Smirnova, Irina; Stepanov, Andrey; Koptsik, Galina

    2016-04-01

    Northwestern part of Russia, the Kola Peninsula, is one of the most heavy metals (HM) contaminated areas in the northern hemisphere. The main polluters, mining-and-metallurgical integrated works "Pechenganikel" and "Severonikel", are surrounded by heavily damaged barren lands that require remediation. The main contaminating metals are Ni and Cu. Using of exogenous humic substances could be possible effective and cost-efficient solution of HM contamination problem. Rational application of humates (Na-K salts of humic acids) can result in improvement of soil properties, localization of contamination and decreasing bioavailability through binding HM in relatively immobile organic complexes. Our research aim was to evaluate the influence of increasing doses of different origin humates on i) basic properties of contaminated soils; ii) mobility and bioavailability of HMs; iii) vegetation state and chemistry. In summer 2013 a model field experiment was provided in natural conditions of the Kola Peninsula. We investigated the Al-Fe-humus abrazem, soil type that dominates in technogenic barren lands around the "Severonikel" work. These soils are strongly acid: pHH2O was 3.7-4.1; pHKCl was 3.4-4.0. The exchangeable acidity is low (0.8-1.6 cmol(+)/kg) due to the depletion of fine particles and organic matter, being the carriers of exchange positions. The abrazems of barrens had lost organic horizon. 12 sites were created in 1 km from the work. In those sites, except 2 controls, various amendments were added: i) two different by it's origin types of humates: peat-humates and coal-humates, the last were in concentrations 0.5% and 1%; ii) lime; iii) NPK-fertilizer; iv) biomates (organic degradable cover for saving warm and erosion protection). As a test-culture a grass mixture with predominance of Festuca rubra and Festuca ovina was sowed. As a result we concluded that humates of different origin have unequal influence on soil properties and cause decreasing as well as

  12. Structure-Property-Function Relationship in Humic Substances to Explain the Biological Activity in Plants

    Science.gov (United States)

    García, Andrés Calderín; de Souza, Luiz Gilberto Ambrosio; Pereira, Marcos Gervasio; Castro, Rosane Nora; García-Mina, José María; Zonta, Everaldo; Lisboa, Francy Junior Gonçalves; Berbara, Ricardo Luis Louro

    2016-02-01

    Knowledge of the structure-property-function relationship of humic substances (HSs) is key for understanding their role in soil. Despite progress, studies on this topic are still under discussion. We analyzed 37 humic fractions with respect to their isotopic composition, structural characteristics, and properties responsible for stimulating plant root parameters. We showed that regardless of the source of origin of the carbon (C3 or C4), soil-extracted HSs and humic acids (HAs) are structurally similar to each other. The more labile and functionalized HS fraction is responsible for root emission, whereas the more recalcitrant and less functionalized HA fraction is related to root growth. Labile structures promote root stimulation at lower concentrations, while recalcitrant structures require higher concentrations to promote a similar stimulus. These findings show that lability and recalcitrance, which are derived properties of humic fractions, are related to the type and intensity of their bioactivity. In summary, the comparison of humic fractions allowed a better understanding of the relationship between the source of origin of plant carbon and the structure, properties, and type and intensity of the bioactivity of HSs in plants. In this study, scientific concepts are unified and the basis for the agronomic use of HSs is established.

  13. Characteristics of Soil Humic Substances as Determined by Conventional and Synchrotron Fourier Transform Infrared Spectroscopy

    Science.gov (United States)

    Wang, S.; Song, X. Y.; Wang, N.; Li, C. X.; Wang, W.; Zhang, J. J.

    2014-11-01

    Humic substances (HS) play an important role in soil fertility and carbon sequestration in soil. The structural characteristics of soil HS, extracted from two natural soils and a laboratory-incubated soil, were investigated by conventional beamline-based Fourier transform infrared radiation (CB-FTIR), a common FTIR technique based on a conventional thermal source, and synchrotron radiation-based (SR-FTIR) spectroscopy. The relative area of absorbance peaks that appeared at 2930, 2860, 1711, and 1635 cm-1 were calculated to make a comparison of the absorbance intensities. The absorption of aromatic functional groups of HS was stronger in SR-FTIR spectroscopy than in CB-FTIR spectroscopy. Compared with humic acid extracted with a 0.1 mol/l Na4P2O7 solution, the level of aliphaticity in humic acid extracted with a 0.1 mol/l NaOH solution was higher. The aliphaticity of humin associated with clay (HMc) was higher than that of humin associated with iron (HMi). These results suggest that SR-FTIR spectroscopy is a useful and nondestructive technique to study the structural characteristics of soil humic substances. Sequential extraction of soil humic substances with NaOH and Na4P2O7 solutions may be helpful in providing additional information in cases where differences in the material obtained from different extraction solutions occur. The aliphaticity and complexity of HMc were higher than those of HMi.

  14. Behavior of aluminum adsorption in different Compost-Derived humic acids

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yong-Hong; Su, Po-Hsin [Kaohsiung District Agricultural Research and Extension Station, Pingtung (China)

    2010-10-15

    Humic acid plays an important role in the distribution of heavy metals in the environment. The aims of this study were conducted to evaluate the spectroscopic characteristics and aluminum (Al) adsorption of humic acids which were extracted from four composts. The functional groups were determined by Fourier transform infrared spectroscopy (FTIR) and solid-state {sup 13}C nuclear magnetic resonance spectroscopy ({sup 13}C-NMR). The results showed that the aromatic groups were all found in the humic acids of the four composts, and the surface of humic acids included carboxylic group, hydroxylic group, and amino group. The experiment of Al adsorption was described by Freundlich equation. It showed that the adsorption of Al by humic acid from compost of cattle manure was higher, but that from the compost of pig manure, lemon manure, tea manure in equal preparation was lower. The adsorptive behavior was different due to the interaction by functional groups (-OH and -COOH) with Al. These results can describe the fate and transportation of Al in the soil of different organic fertilizer. (Copyright copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. 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.

  16. Mechanisms for the suppression of methane production in peatland soils by a humic substance analog

    Science.gov (United States)

    Ye, R.; Keller, J. K.; Jin, Q.; Bohannan, B. J. M.; Bridgham, S. D.

    2014-01-01

    Methane (CH4) production is often impeded in many northern peatland soils, although inorganic terminal electron acceptors (TEAs) are usually present in low concentrations in these soils. Recent studies suggest that humic substances in wetland soils can be utilized as organic TEAs for anaerobic respiration and may directly inhibit CH4 production. Here we utilize the humic analog anthraquinone-2, 6-disulfonate (AQDS) to explore the importance of humic substances, and their effects on the temperature sensitivity of anaerobic decomposition, in two peatland soils. In a bog peat, AQDS was not instantly utilized as a TEA, but greatly inhibited the fermentative production of acetate, carbon dioxide (CO2), and hydrogen (H2), as well as CH4 production. When added together with glucose, AQDS was partially reduced after a lag period of 5 to 10 days. In contrast, no inhibitory effect of AQDS on fermentation was found in a fen peat and AQDS was readily reduced as an organic TEA. The addition of glucose and AQDS to both bog and fen peats caused complicated temporal dynamics in the temperature sensitivity of CH4 production, reflecting temporal changes in the temperature responses of other carbon processes with effects on methanogenesis. Our results show that the humic analog AQDS can act both as an inhibitory agent and a TEA in peatland soils. The high concentrations of humic substances in northern peatlands may greatly influence the effect of climate change on soil carbon cycling in these ecosystems.

  17. The effects of humic acid on nutrient status yield and quality of tomato

    Directory of Open Access Journals (Sweden)

    Elif Işıl DEMİRTAŞ

    2014-06-01

    Full Text Available In order to increase organic matter content of soil, humic acid application is the most economic and fast method. In this study, the effects of humic acid and their dosages (0, 4, 8, 12, 16 and 20 L da-1 on nutritional, status of tomato and yield-quality were investigated. During the growing period, a dose of NPK was applied through drip irrigation. The experiment was carried out according to randomized complete block design with four replications under greenhouse conditions in 2011-2013 autumn tomato growing season. In order to determine effects of humic acid, plant and leaves fruit were analyzed during the experiment. The results of analysis showed that increases of N, P, K, Fe, Cu content of tomato leaves was found important whereas Ca, Mg, Mn, Zn and B content was not important statistically. The effect of humic acid+NPK applications on fruit quality of tomato was positive. Fruit yield was increased by humic acid applications compared to control.

  18. Degraded Crater

    Science.gov (United States)

    2004-01-01

    21 October 2004 Near the center of this Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image lies the degraded remnants of an old meteor impact crater. The terrain in which it occurs is a heavily eroded, north middle-latitude surface. The image is located in the fretted terrains north of Arabia Terra near 41.3oN, 305.8oW. The image covers an area about 3 km (1.9 mi) wide and sunlight illuminates the scene from the lower left.

  19. Sorption of tylosin and sulfamethazine on solid humic acid.

    Science.gov (United States)

    Guo, Xuetao; Tu, Bei; Ge, Jianhua; Yang, Chen; Song, Xiaomei; Dang, Zhi

    2016-05-01

    Tylosin (TYL) and sulfamethazine (SMT) are ionizable and polar antimicrobial compounds, which have seeped into the environment in substantial amounts via fertilizing land with manure or sewage. Sorption of TYL and SMT onto humic acid (HA) may affect their environmental fate. In this study, the sorption of TYL and SMT on HA at different conditions (pH, ionic strength) was investigated. All sorption isotherms fitted well to the Henry and Freundlich models and they were highly nonlinear with values of n between 0.5 and 0.8, which suggested that the HA had high heterogeneity. The sorption of TYL and SMT on HA decreased with increasing pH (2.0-7.5), implying that the primary sorption mechanism could be due to cation exchange interactions between TYL(+)/SMT(+) species and the functional groups of HA. Increasing ionic strength resulted in a considerable reduction in the Kd values of TYL and SMT, hinting that interactions between H bonds and π-π EDA might be an important factor in the sorption of TYL and SMT on HA. Results of Fourier transform infrared (FT-IR) and (13)C-nuclear magnetic resonance (NMR) analysis further demonstrated that carboxyl groups and O-alkyl structures in the HA could interact with TYL and SMT via ionic interactions and H bonds, respectively. Overall, this work gives new insights into the mechanisms of sorption of TYL and SMT on HA and hence aids us in assessing the environmental risk of TYL and SMT under diverse conditions. Copyright © 2015. Published by Elsevier B.V.

  20. Stability constant of the lanthanum complex with humic acid; Constante de estabilidad del complejo de lantano con acido humico

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez R, M.; Solache R, M. J. [ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico)

    2008-07-01

    The work described here is a study on the formation of trivalent lanthanum complex with humic acid. Commercial humic acid was purified and then characterized by various analytical techniques. The stability constant determined by a radiochemical method has a worth of log {beta}{sub La},{sub AHA} = 13.6. (Author)

  1. Comparative study of humic and fulvic substances in groundwaters. Pt. 3

    International Nuclear Information System (INIS)

    Higgo, J.J.W.; Davis, J.; Smith, B.

    1992-01-01

    Humic and fulvic acids were extracted from large volumes of three different groundwaters. After purification they were characterised in terms of proton-binding properties, molecular weight, UV spectra and trace impurities. Conditional stability constants were measured for fulvic and humic binding with cobalt, nickel, calcium and uranium. From these, intrinsic binding constants were calculated using Humic Ion-Binding Model V which was found to describe the dependence of binding strength on pH and ionic strength reasonably well. Species distributions in the groundwaters were calculated and the effects of competition with alkali earths are discussed. All the experimental data are reported in a separate volume (Appendix A and B) so that they are available for testing other models. (author)

  2. Structural relationship between humic fractions from peat and lignites from the Miocene Granada basin

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Vila, F.J.; Rio, J.C. del; Almendros, G.; Martin, F. [Instituto de Recursos Naturales y Agrobiologia de Sevilla, Sevilla (Spain)

    1994-02-01

    Fulvic acids, humic acids and humins, isolated from two closely situated peat and lignite deposits, have been examined by solid-state {sup 13}C n.m.r. and analytical pyrolysis. No marked structural differences were found between the humic fractions from the various deposits, suggesting a common origin. Within each deposit some distinguishing structural characteristics were observed between the humic fractions. The differences observed showed that the loss of carbohydrate and lignin during the early coalification process led to the accumulation of a predominantly polyalkyl, kerogen-like residue. The humin fractions from both materials contain the greatest amount of aromatic structures, although they also present high proportions of aliphatic components. Thus, their n.m.r. spectra consist almost exclusively of alkyl and aromatic hydrocarbon entities. This agreed with the results of pyrolysis, which reflected the presence in humins of condensed alkyl material. 42 refs., 3 figs., 3 tabs.

  3. Methodology to extract of humic substances of lombricompost and evaluation of their performance

    International Nuclear Information System (INIS)

    Torrente Trujillo, Armando; Gomez Zambrano, Jairo

    1995-01-01

    The present works was developed at the facultad de ciencias agropecuarias of the Universidad Nacional de Colombia, located in Palmira City Valle del Cauca. The research consisted in the development of the appropriate methodology to extract humic substances contained in lombricompost and on the other hand to evaluate the performance in organic carbon of the fulvic and humic acids. The lombricompost source consisted in organic matter such as: dug cow, filter press cake, coffee pulp and Paspalum notatum with and without application of lime. The results showed sixteen steps, which are completely described in the work, obtain the proposal methodology. By the other hand this method showed that humic acids in the lombricompost are richer than fulvic ones; besides among the four sources used in the experiment the filter press cake was different and higher in carbon yield than coffee pulp and Paspalum notatum

  4. Humic acid batteries derived from vermicomposts at different C/N ratios

    Science.gov (United States)

    Shamsuddin, R. M.; Borhan, A.; Lim, W. K.

    2017-06-01

    Humic acid is a known fertilizer derived from decomposed organic matters. Organic wastes are normally landfilled for disposal which had contributed negatively to the environment. From waste-to-wealth perspective, such wastes are potential precursors for compost fertilizers. When worms are added into a composting process, the process is termed as vermicomposting. In this work, humic acid from vermicompost derived from campus green wastes was developed into a battery. This adds value proposition to compost instead of being traditionally used solely as soil improver. This research work aimed to study the correlation between electrical potential generated by humic acid at different Carbon to Nitrogen (C/N) ratios of vermicompost at 20, 25, 30 and 35. The temperature and pH profiles of composting revealed that the compost was ready after 55 days. The humic acid was extracted from compost via alkaline extraction followed by precipitation in a strong acid. The extracted humic acid together with other additives were packed into a compartment and termed as vermibattery. Another set of battery running only on the additives was also prepared as a control. The net voltage produced by a single vermibattery cell with Zn and PbO electrodes was in the range of 0.31 to 0.44 V with compost at C/N ratio of 30 gave the highest voltage. The battery can be connected in series to increase the voltage generation. Quality assessment on the compost revealed that the final carbon content is between 16 to 23 wt%, nitrogen content of 0.4 to 0.5 wt%, humic acid yield of 0.7 to 1.5 wt% and final compost mass reduction of 10 to 35 wt%. Composting campus green wastes carries multi-fold benefits of reducing labour requirement, generating fertilizer for campus greenery and green battery construction.

  5. Removal of Radium-226 from Radium-Contaminated Soil using Distilled Water and Humic Acid: Effect of pH

    International Nuclear Information System (INIS)

    Phillips, E.; Muhammad Samudi Yasir; Muhamat Omar

    2011-01-01

    Effect of washing solutions' pH removal of radium-226 from radium-contaminated soil using distilled water and humic acid extracted from Malaysian peat soil was studied by batch washing method. The study encompassed the extraction of humic acid and the washing of radium-contaminated soil using distilled water and humic acid solutions of 100 ppm, both with varying pHs in the range of 3 to 11. The radioactivity concentration of radium-226 was determined by gamma spectrometer.The removal of radium-226 was greater when humic acid solutions were used compared to distilled water at the pH range studied and both washing solutions showed greater removal of radium-226 when basic solutions were used. Nevertheless, comparable removal efficiencies were observed when neutral and highly basic humic acid solutions were used. (author)

  6. Formation of N-nitrosodimethylamine (NDMA) from humic substances in natural water.

    Science.gov (United States)

    Chen, Zhuo; Valentine, Richard L

    2007-09-01

    N-nitrosodimethylamine (NDMA)formation in chloraminated Iowa River water (IRW) is primarily attributed to reactions with natural organic matter (NOM) generally classified as humic substances. Experiments were conducted to determine the contribution of various NOM humic fractions to the NDMA formation potential (NDMA FP) in this drinking water source. NOM was concentrated by reverse osmosis (RO) and humic fractions were obtained by a series of resin elution procedures. Mass balances showed that nearly 90% of the NDMA formation potential could be recovered in the NOM concentrate and in water reconstituted using additions of the various humic fractions. Generally, the hydrophilic fractions tended to form more NDMA than hydrophobic fractions, and basic fractions tend to form more NDMA than acid fractions when normalized to a carbon basis. Overall, the hydrophobic acid fraction was the dominant source of NDMA when both formation efficiency and water composition were considered. The amount of NDMA formed in a sample was found to correlate linearly with an oxidation-induced decrease in specific UV absorbance (SUVA) value at 272 nm. This is consistent with a mechanism in which precursors are formed as the direct consequence of the oxidation of NOM. The NDMA FP estimated using the slope of this relationship and the initial SUVA value compared closely to the value obtained by measuring the NDMA formed in solutions dosed with excess concentrations of monochloramine that presumably exhaust all potential precursor sources. However, the NOMA FP could not be correlated to the SUVA value of the individual humic fractions indicating that the relationship of the NDMA FP to SUVA value is probably a water-specific parameter dependent on the exact composition of humic fractions. It is hypothesized that either specific NDMA precursors are distributed among the various humic fractions or that the humic material itself represents a "generic" nonspecific precursor source that requires some

  7. 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.

  8. Hydroxypropyl-β-cyclodextrin extractability and bioavailability of phenanthrene in humin and humic acid fractions from different soils and sediments.

    Science.gov (United States)

    Gao, Huipeng; Ma, Jing; Xu, Li; Jia, Lingyun

    2014-01-01

    Organic matter (OM) plays a vital role in controlling polycyclic aromatic hydrocarbon (PAH) bioavailability in soils and sediments. In this study, both a hydroxypropyl-β-cyclodextrin (HPCD) extraction test and a biodegradation test were performed to evaluate the bioavailability of phenanthrene in seven different bulk soil/sediment samples and two OM components (humin fractions and humic acid (HA) fractions) separated from these soils/sediments. Results showed that both the extent of HPCD-extractable phenanthrene and the extent of biodegradable phenanthrene in humin fraction were lower than those in the respective HA fraction and source soil/sediment, demonstrating the limited bioavailability of phenanthrene in the humin fraction. For the source soils/sediments and the humin fractions, significant inverse relationships were observed between the sorption capacities for phenanthrene and the amounts of HPCD-extractable or biodegradable phenanthrene (p humin fractions, with both slopes close to 1. On the other hand, in the case of phenanthrene contained in HA, a poor relationship was observed between the amount of phenanthrene extracted by HPCD and the amount degraded, with the former being much less than the latter. The results revealed the importance of humin fraction in affecting the bioavailability of phenanthrene in the bulk soils/sediments, which would deepen our understanding of the organic matter fractions in affecting desorption and biodegradation of organic pollutants and provide theoretical support for remediation and risk assessment of contaminated soils and sediments.

  9. Combined photo-Fenton and biological treatment for Diuron and Linuron removal from water containing humic acid

    International Nuclear Information System (INIS)

    Farre, Maria Jose; Domenech, Xavier; Peral, Jose

    2007-01-01

    A combined chemical (photo-Fenton) and biological treatment has been proposed for Diuron and Linuron degradation in water containing natural dissolved organic matter (DOM). Humic acid (HA) was used to simulate the DOM. During the photo-Fenton process ([Fe(II)]=15.9mgL -1 , [H 2 O 2 ]=202mgL -1 , 60min of UVA irradiation time), the chemical oxygen demand (COD), total organic carbon (TOC), toxicity (EC 50 15 ) and biodegradability (BOD 5 /COD) of the generated intermediates were assessed. A reduction of photo-Fenton efficiency was observed when HA was present in solution. This effect has been explained as the result of a UVA light screening as well as a OH? radical quenching process by the HA. After the photo-Fenton process, the initial toxic and non-biodegradable herbicides were transformed into intermediates suitable for a subsequent aerobic biological treatment that was performed in a sequencing batch reactor (SBR). Complete elimination of the intermediates in presence of HA was reached at the end of the chemical-biological coupled system. Biosorption of HA onto the aerobic biomass was characterized. The results indicate that the Freundlich model adequately describes the adsorption of HA, a phenomena that follows a pseudo second-order adsorption kinetic model

  10. Combined photo-Fenton and biological treatment for Diuron and Linuron removal from water containing humic acid

    Energy Technology Data Exchange (ETDEWEB)

    Farre, Maria Jose [Departament de Quimica, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Domenech, Xavier [Departament de Quimica, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Peral, Jose [Departament de Quimica, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain)]. E-mail: jose.peral@uab.es

    2007-08-17

    A combined chemical (photo-Fenton) and biological treatment has been proposed for Diuron and Linuron degradation in water containing natural dissolved organic matter (DOM). Humic acid (HA) was used to simulate the DOM. During the photo-Fenton process ([Fe(II)]=15.9mgL{sup -1}, [H{sub 2}O{sub 2}]=202mgL{sup -1}, 60min of UVA irradiation time), the chemical oxygen demand (COD), total organic carbon (TOC), toxicity (EC{sub 50}{sup 15}) and biodegradability (BOD{sub 5}/COD) of the generated intermediates were assessed. A reduction of photo-Fenton efficiency was observed when HA was present in solution. This effect has been explained as the result of a UVA light screening as well as a OH? radical quenching process by the HA. After the photo-Fenton process, the initial toxic and non-biodegradable herbicides were transformed into intermediates suitable for a subsequent aerobic biological treatment that was performed in a sequencing batch reactor (SBR). Complete elimination of the intermediates in presence of HA was reached at the end of the chemical-biological coupled system. Biosorption of HA onto the aerobic biomass was characterized. The results indicate that the Freundlich model adequately describes the adsorption of HA, a phenomena that follows a pseudo second-order adsorption kinetic model.

  11. Influence of Biogenically Produced Fe(II) and Humic Acid Analogs on the Fate of 2,4,6-Trinitrotoluene (TNT)

    Science.gov (United States)

    Borch, T.; Gerlach, R.; Cunningham, A. B.; Peyton, B. M.; Apel, W. A.

    2002-12-01

    Pollution of soil and groundwater with explosives, such as TNT, is a well-known environmental problem. Obviously, a precise risk assessment and evaluation of appropriate remediation strategies of TNT require a fundamental understanding of the processes that govern the transformation of TNT in the subsurface. Recently a number of novel Gram positive metal-reducing bacteria were isolated from enrichments of subsurface soils from Cr(VI) contaminated and uncontaminated zones at the US Department of Energy's Hanford site. In contrast to most known metal-reducing bacteria such as Geobacter spp. and Shewanella spp. the isolates were predominantly Gram-positive and 16S rDNA and phospholipid analysis indicated that the isolates predominantly belonged to commonly observed soil bacteria of the genus Cellulomonas. These isolates proved to be capable of Cr(VI), U(VI), dissolved Fe(III), goethite, maghemite, magnetite, hematite, and hydrous ferric oxide (HFO) reduction. Reduced solid phase iron can mediate the degradation of nitroaromatics, halogenated solvents, azo compounds, arsenate, and other important contaminants. Consequently, batch experiments were conducted with Fe(III) minerals (namely, HFO and Magnetite) to investigate the impact of biogenically produced Fe(II) on the fate of TNT. The humic acid analog anthraquinone-2,6-disulfonate (AQDS), can be reduced by Cellulomonas spp. and was included in these studies because of its ability to function as an electron shuttle between the Fe(III) minerals and the bacterial cell during microbial iron reduction. The work to be presented systematically investigates how different factors control the rate and extent of TNT reduction reactions as well as the mechanisms involved. Anaerobic batch studies show the fastest and most complete reduction of TNT in the presence of HFO and the humic analog AQDS. However, we also observe TNT removal by Cellulomonas in the absence of HFO and AQDS with similar TNT reduction rates but with the

  12. Title: Effects of supplementing humic/fulvic acid on rumen ...

    African Journals Online (AJOL)

    Casey McMurphy

    , N.A., Galyean, M.L., Duff, G.C., Cole, N.A. & Rivera, J.D., 2004. Effects of crude protein concentration and degradability on performance, carcass characteristics, and serum urea nitrogen concentrations in finishing beef steers. J. Anim. Sci.

  13. Radiolytic degradation of malathion and lindane in aqueous solutions

    International Nuclear Information System (INIS)

    Mohamed, K.A.; Basfar, A.A.; Al-Kahtani, H.A.; Al-Hamad, K.S.

    2009-01-01

    Degradation of malathion and lindane pesticides present in an aqueous solution was investigated on a laboratory scale upon gamma-irradiation from a 60 Co source. The effects of pesticide group, presence of various additives and absorbed dose on efficiency of pesticide degradation were investigated. Gamma-irradiation was carried out in distilled water solutions (malathion and lindane) and in combination with humic solution (HS), nitrous oxide (N 2 O) and HS/N 2 O (lindane) over the range 0.1-2 kGy (malathion) and 5-30 kGy (lindane). Malathion was easily degraded at low absorbed doses compared to lindane in distilled water solutions. Absorbed doses required to remove 50% and 90% of initial malathion and lindane concentrations in distilled water solutions were 0.53 and 1.77 kGy (malathion) and 17.97 and 28.79 kGy (lindane), respectively. The presence of HS, N 2 O and HS/N 2 O additives in aqueous solutions, significantly improved the effectiveness of radiolytic degradation of lindane. Chemical analysis of the pesticides and the by-products resulted from the radiolytic degradation were made using a gas chromatography associated with mass spectrometry (GC-MS). Additionally, the final degradation products of irradiation as detected by ion chromatography (IC) were acetic acid and traces of some anions (phosphate and chloride).

  14. Complexation behavior of Np(IV) and humic acid

    International Nuclear Information System (INIS)

    Iijima, Kazuki; Tobitsuka, Sachiko; Kohara, Yukitoshi

    2004-04-01

    Complexation behavior between humic acid (HA), which is one of the natural organic matter in groundwater, and tetravalent neptunium (Np(IV)) was investigated by batch type complexation experiments and solvent extraction by TTA xylene, focused on the effect of concentration and molecular weight of HA. In addition, proton dissociation behavior from HA was evaluated by acid-base titration and its results was used for the calculation of stability constant of Np(IV) and HA complex. The results of titration of HA was analysed based on NICA-Donnan model and parameters used for evaluation of proton dissociation behavior were calculated. The charge density of HA in pH 8, which is necessary for calculation of stability constant, was evaluated as -4.35 meq/g. The complexation experiments were carried out under the conditions as follows; 1x10 -5 mol/l of initial Np concentration, from 5 to 500 mg/l of HA concentration, pH 8, in the 0.1 mol/l NaClO 4 , and 0.05 mol/l Na 2 S 2 O 4 as reductant to keep Np as tetravalent. As a result, in the presence of 5 mg/l of HA, total concentration of Np was increased at least one order of magnitude higher than in the case without HA. All added Np existed as soluble species in the presence of more than 50 mg/l of HA. Np in the solution was fractionated by solvent extraction using TTA-xylene as follows; 1) extractable Np into the organic phase, 2) non-extractable Np remained in the inorganic phase, and 3) precipitated Np. These were considered as 1) free Np(VI) or weakly binded Np(IV) and 3) strongly binded Np(IV), while 2) Np(IV)-fulvic acid complex could be suggested. Consequently, stability constant, log β α =26.31, was obtained. In addition, compared with Am(III) or Np(V), accessible site in the HA for Np(IV) seems to be quite limited. (author)

  15. Degradation of bisphenol-A using ultrasonic irradiation assisted by low-concentration hydrogen peroxide.

    Science.gov (United States)

    Zhang, Kejia; Gao, Naiyun; Deng, Yang; Lin, Tsair Fuh; Ma, Yan; Li, Lei; Sui, Minghao

    2011-01-01

    This study investigated the degradation of bisphenol-A (BPA) by ultrasonic irradiation in the presence of different additives (H2O2, air bubbles and humic acid) under various operating conditions, i.e., ultrasonic frequency, power intensity and power density. The results demonstrated that the BPA degradation followed pseudo first-order kinetics under different experimental conditions. The optimum power intensities were 0.9, 1.8, and 3.0 W/cm2 at the frequencies of 400, 670, and 800 kHz, respectively. At the fixed frequency (800 kHz), the degradation rate of BPA was shown proportional to the increase of power density applied. With this manner, the BPA sonolysis could be facilitated at H2O2 dosage being lower than 0.1 mmol/L; while BPA degradation was hindered at H2O2 concentration in excess of 1 mmol/L. Additionally, BPA removal was shown to be inhibited by the presence of aeration and humic acid during ultrasonic irradiation. The present study suggested that the degradation rate of BPA assisted by ultrasonic irradiation was influenced by a variety of factors, and high BPA removal rate could be achieved under appropriate conditions.

  16. Humic acid and enzymes in canola-based broiler diets: Effects on ...

    African Journals Online (AJOL)

    Gross lesion analysis displayed high prevalence of rickets in boilers fed CMEnz diet compared with all other dietary treatments. Intestinal morphometric parameters demonstrated some dietary differences in the height and width of the intestinal villi and intestinal crypts. In conclusion, inclusion of humic acid in canola-based ...

  17. Humic acid as a model for natural organic matter (NOM) in the ...

    African Journals Online (AJOL)

    Current practices in some water-treatment facilities have reported that natural organic matter (NOM) blocks the adsorption sites of activated carbon resulting in lower geosmin and 2-methylisoborneol (2-MIB) removal. Humic acid has been reported to compete with geosmin and 2-MIB removal in the same way. The removal ...

  18. CHARACTERIZATION OF SOIL HUMIC SUBSTANCES BY ULTRAVIOLET-VISIBLE AND SYNCHRONOUS FLUORESCENCE SPECTROSCOPY

    Directory of Open Access Journals (Sweden)

    NADĚŽDA FASUROVÁ

    2011-01-01

    Full Text Available We focused our study on ultraviolet-visible and synchronous fluorescence spectra and indexes of humic subctances isolated from five Czech soil samples: Haplic Chernozem, Luvic Chernozem, Gleyic Luvisol, Haplic Cambisol and Leptic Cambisol. Results indicated the following HS quality: Haplic Chernozem > Luvic Chernozem > Gleyic Luvisol > Haplic Cambisol > Leptic Cambisol. Humic acids and fulvic acids ratios (HA/FA were increasing together with decreasing values of Q4/6 measured in visible spectral range. Highest absorbance in visible spectral range was detected in Haplic Chernozem and Luvic Chernozem. Maximum relative fluorescence was found in Haplic Chernozem. SFS spectra (in emission mode at Δλ=20 nm showed five main fluorophore peaks at: 360, 470, 488, 502 and 512 nm. Fluorescence behaviour of studied samples was compared with Elliot soil humic acid standard (IHSS. Correlation between fluorescence indexes (F and humification degree (HD R2= 0.88 and between calculated humification degree (HD* and humic acids content (HA sum R2=0.84 and between fluorescence indexes F and HA/FA ratios (R2=0.88 were found.

  19. 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.

  20. Surfactive stabilization of multi-walled carbon nanotube dispersions with dissolved humic substances

    Energy Technology Data Exchange (ETDEWEB)

    Chappell, Mark A. [Environmental Laboratory, Engineering Research and Development Center, US Army Corps of Engineers, 3909 Halls Ferry Road, Vicksburg, MS 39180 (United States)], E-mail: mark.a.chappell@usace.army.mil; George, Aaron J.; Dontsova, Katerina M.; Porter, Beth E. [SpecPro, Inc., 4815 Bradford Drive, Suite 201, Huntsville, AL 35805 (United States); Price, Cynthia L. [Environmental Laboratory, Engineering Research and Development Center, US Army Corps of Engineers, 3909 Halls Ferry Road, Vicksburg, MS 39180 (United States); Zhou Pingheng; Morikawa, Eizi [J. Bennett Johnston Sr. Center for Advanced Microstructures and Devices, Louisiana State University, 6980 Jefferson Highway, Baton Rouge, LA 70806 (United States); Kennedy, Alan J.; Steevens, Jeffery A. [Environmental Laboratory, Engineering Research and Development Center, US Army Corps of Engineers, 3909 Halls Ferry Road, Vicksburg, MS 39180 (United States)

    2009-04-15

    Soil humic substances (HS) stabilize carbon nanotube (CNT) dispersions, a mechanism we hypothesized arose from the surfactive nature of HS. Experiments dispersing multi-walled CNT in solutions of dissolved Aldrich humic acid (HA) or water-extractable Catlin soil HS demonstrated enhanced stability at 150 and 300 mg L{sup -1} added Aldrich HA and Catlin HS, respectively, corresponding with decreased CNT mean particle diameter (MPD) and polydispersivity (PD) of 250 nm and 0.3 for Aldrich HA and 450 nm and 0.35 for Catlin HS. Analogous trends in MPD and PD were observed with addition of the surfactants Brij 35, Triton X-405, and SDS, corresponding to surfactant sorption maximum. NEXAFS characterization showed that Aldrich HA contained highly surfactive domains while Catlin soil possessed a mostly carbohydrate-based structure. This work demonstrates that the chemical structure of humic materials in natural waters is directly linked to their surfactive ability to disperse CNT released into the environment. - Suspensions of multi-walled carbon nanotubes are stabilized by relatively low concentrations of dissolved humic substances in solution through surfactive mechanisms.

  1. Response of sugar beet to humic substances and foliar fertilization with potassium

    Directory of Open Access Journals (Sweden)

    Edward Wilczewski

    2018-03-01

    Full Text Available Sugar beet (Beta vulgaris L. requires fertile soils with high biological activity, rich in minerals and organic nutrients. Biological properties of soil, such as enzymatic and microbial activity, can be effectively improved through the application of humic substances. This enables an increase in growth dynamics and, consequently, in the yield. The aim of this study was to assess sugar beet germination, depending on the soil application of the humic preparation Humistar (12% of humic acids, 3% of fulvic acids as well as to assess the yield of sugar beet storage roots and the content of sugar in these storage roots, depending on soil applications of Humistar and/or foliar application of potassium fertilizer Drakar (31% K2O, 3% N. The field experiment was conducted in the soil classified as Mesic Typic Hapludalfs. Soil application of Humistar contributed to a reduction in sugar beet germination, measured as % of plants germinated within 14 days after sowing. However, the growth of plants in soil with Humistar was more intensive than in the control. A significant, positive influence of Humistar and Drakar on the yield of sugar beet roots has been found. Application of the two treatments did not produce better results than the use of each of them separately. Sugar content in roots was not affected by experimental factor. The study showed that both soil application of humic substances and the use of foliar potassium fertilizer can improve the yield of sugar beet and, consequently, increase the biological yield of sugar from storage roots.

  2. Effects of extraction period on yield of rice straw compost humic acids

    African Journals Online (AJOL)

    ... terms of chemical and spectral characteristics. HA from rice straw compost can be extracted within 24 h and purification can be done in relatively short time without changing their chemical and spectral properties to produce K-humate. Key words: Humic acids, rice straw compost, spectral characteristics, extraction period, ...

  3. Ultraviolet-visible absorptive features of water extractable and humic fractions of animal manure and compost

    Science.gov (United States)

    UV-vis spectroscopy is a useful tool for characterizing water extractable or humic fractions of natural organic matter (WEOM). Whereas the whole UV-visible spectra of these fractions are more or less featureless, the specific UV absorptivity at 254 and 280 nm as well as spectral E2/E3 and E4/E6 rat...

  4. Interactions between radionuclides and organic colloids. Structure and reactivity of humic compounds

    International Nuclear Information System (INIS)

    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.)

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

    African Journals Online (AJOL)

    Fruit production and quality of guava 'Paluma' as a function of humic substances and soil mulching. Leonardo Fonseca da Rocha, Lourival Ferreira Cavalcante, Járisson Cavalcante Nunes, Antônio Gustavo de Luna Souto, Alian Cássio Pereira Cavalcante, Ítalo Herbert Lucena Cavalcante, Walter Esfrain Pereira ...

  6. Influence of Humic Acid on the Transport and Deposition of Colloidal Silica under Different Hydrogeochemical Conditions

    Directory of Open Access Journals (Sweden)

    Jingjing Zhou

    2016-12-01

    Full Text Available The transport and deposition of colloids in aquifers plays an important role in managed aquifer recharge (MAR schemes. Here, the processes of colloidal silica transport and deposition were studied by displacing groundwater with recharge water. The results showed that significant amounts of colloidal silica transport occurred when native groundwater was displaced by HA solution. Solution contains varying conditions of ionic strength and ion valence. The presence of humic acid could affect the zeta potential and size of the colloidal silica, which led to obvious colloidal silica aggregation in the divalent ion solution. Humic acid increased colloidal silica transport by formation of non-adsorbing aqueous phase silica–HA complexes. The experimental and modeling results showed good agreement, indicating that the essential physics were accurately captured by the model. The deposition rates were less than 10−8 s−1 in deionized water and monovalent ion solution. Moreover, the addition of Ca2+ and increase of IS resulted in the deposition rates increasing by five orders of magnitude to 10−4 s−1. In all experiments, the deposition rates decreased in the presence of humic acid. Overall, the promotion of humic acid in colloidal silica was strongly associated with changes in water quality, indicating that they should receive greater attention during MAR.

  7. Characterization of aquatic humic substances to DBPs formation in advanced treatment processes for conventionally treated water.

    Science.gov (United States)

    Kim, Hyun-Chul; Yu, Myong-Jin

    2007-05-08

    An advanced water treatment demonstration plant consisted of ozone/granular activated carbon processes was operated to study feasibility of the processes. Natural organic matter (NOM) from raw and process waters at the demonstration plant was isolated into humic and non-humic fractions by physicochemical fractionation method to investigate characteristics of humic fraction (i.e., humic substances, HS) as a predominant haloform reactant. Ozone did not significantly oxidize the carboxylic fraction (from 39.1 to 35.9%), while GAC removed some of the carboxylic fraction (from 35.9 to 29.1%). Formation potential of trihalomethanes (THMs) as compared to haloacetic acids formation potential (HAAFP) was highly influenced by HS. Higher yields of THMs resulted from chlorination of HS with a higher phenolic content and phenolic fraction in the HS gradually decreased from 60.5% to 15.8% through the water treatment. The structural and functional changes of HS were identified by elemental, Fourier-transform infrared (FT-IR) and proton nuclear magnetic resonance ((1)H NMR) analyses, and these results were mutually consistent. The functional distribution data obtained by using A-21 resin could be used to support the interpretation of data obtained from the spectroscopic analyses. Decreases in ratio of UV absorbance at 253 nm and 203 nm (A(253)/A(203)) and DBPFPs/DOC showed consistent trends, therefore, A(253)/A(203) ratio may be a good indicator for the disinfection by-product formation potentials (DBPFPs).

  8. 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

  9. Proton binding properties of humic substances originating from natural and contaminated materials

    NARCIS (Netherlands)

    Zomeren, van A.; Costa, A.; Pinheiro, J.P.; Comans, R.N.J.

    2009-01-01

    Humic substances (HS) are ubiquitous organic constituents in soil and water and can strongly adsorb metal contaminants in natural and waste environments. Therefore, understanding and modeling contaminant-HS interactions is a key issue in environmental risk assessment. Current binding models for HS,

  10. Isotope exchange study of the dissociation of metal - humic substance complexes

    Czech Academy of Sciences Publication Activity Database

    Mizera, J.; Jansová, A.; Hvoždová, I.; Beneš, P.; Novák, František

    2003-01-01

    Roč. 53, A (2003), s. A97-A101 ISSN 0011-4626 Institutional research plan: CEZ:AV0Z6066911; CEZ:MSM 210000019 Keywords : isotope exchange * dissociation of metal * humic substance complexes Subject RIV: EH - Ecology, Behaviour Impact factor: 0.263, year: 2003

  11. Bacterial growth in humic waters exposed to UV-radiation and simulated sunlight

    DEFF Research Database (Denmark)

    Corin, N.; Backlund, P.; Wiklund, T.

    1998-01-01

    Sterile filtered (0.45 mu m) humic lake water was exposed to simulated sunlight (300-800 nm) or W-radiation (254 run)for various periods of times and the dissolved organic carbon content, absorbance at 254 and 460 nm and PH were recorded. The irradiated water was inoculated with a natural bacterial...

  12. Impact of the application of humic acid and sodium nitroprusside on ...

    African Journals Online (AJOL)

    Nickel (Ni) is an essential micronutrient for plants but in high concentrations may turn toxic. This paper discusses the potential role of humic acid (HA) and sodium nitroprusside in modulating or preventing oxidative stress in rice plants. Three genes [superoxide dismutase (SOD) glutathione reductase (GR) and ascorbate ...

  13. Effect of compost amendment on soil organic matter and humic substances

    Science.gov (United States)

    Roca-Pérez, L.; Gil, C.; Jurado, M.; Pons, V.; Boluda, R.

    2009-04-01

    Organic soil amendments are increasingly being examined for their potential use to improve soil functions and quality. We studied the effect of compost amendment on soil organic matter (SOM) and humic substances. The study was carried out on Luvic Calcisol in the Valencian Community (East Spain) used as a citrus fruit orchard. Four plots were amended at dose 0, 6, 12 and 36 Mg ha-1 of rice residue and sewage sludge compost. Seven soil samples for each treatment at depths of 0-10 and 10-20 cm were taken in the first seven months after application. Soil characteristics, SOM, mineral nitrogen, total nitrogen, NH4+-N, and fulvic and humic acids were determined. The results demonstrated that the use of organic compost considerably increases SOM, total nitrogen and the humic substances such as the applied dose. The level of humic substances remained without significant variations during the experimental period. The dose of 36 Mg ha-1 proved the most efficient. We would like to thank Spanish government-MICINN for partial funding and support (MIMAN project 4.3-141/2005/3-B and MICINN project CGL2006-09776).

  14. Bioremoval of humic acid from water by white rot fungi: exploring the removal mechanisms

    NARCIS (Netherlands)

    Zahmatkesh, M.; Spanjers, H.L.F.M.; Toran, M. J.; Blánquez, P.; van Lier, J.B.

    2016-01-01

    © 2016, The Author(s).Twelve white rot fungi (WRF) strains were screened on agar plates for their ability to bleach humic acid (HA). Four fungal strains were selected and tested in liquid media for removal of HA. Bioremediation was investigated by HA color removal and changes in the concentration

  15. Phenoloxidase-mediated interactions of phenols and anilines with humic materials

    Energy Technology Data Exchange (ETDEWEB)

    Dec, J.; Bollag, J.M.

    2000-06-01

    Phenoloxidases present in terrestrial systems may contribute to the formation of humus through random coupling of a variety of aromatic compounds, including xenobiotic chemicals. Because of their structural similarity to natural substrates originating mainly from lignin decomposition, xenobiotic phenols and anilines can be readily incorporated into the soil organic matter, a phenomenon referred to as binding. The underlying mechanism of binding involves oxidation of the xenobiotic substrates to free radicals or quinone products that subsequently couple directly to humus or to naturally occurring phenols that also are subject to oxidation. The oxidation can be mediated by soil phenoloxidases as well as by abiotic catalysts. The ability of the enzymes to mediate the oxidation was demonstrated in a number of model studies, in which selected pollutants were incubated with humic monomers or natural humic acids in the presence of different phenoloxidases (laccase, peroxidase, tyrosinase). Analysis of the formed complexes by mass spectrometry and {sup 13}C nuclear magnetic resonance (NMR) spectroscopy left no doubt about the formation of covalent bonds between the pollutants and humic materials. Some bonds were formed at the chlorinated sites, leading to partial dehalogenation of the aromatic contaminants. Experimental data indicated that bound phenols and anilines were unlikely to adversely affect the environment; their release from humic complexes by soil microorganisms was very limited and once released, they were subjected to mineralization. For those reasons, phenoloxidases, which proved capable of mediating the underlying reaction, are currently considered as a tool for enhancing immobilization phenomena in soil.

  16. The effect of humic substances on germination and early growth of Lamb's Quarters (Chenopodium album agg.)

    Czech Academy of Sciences Publication Activity Database

    Šerá, Božena; Novák, František

    2011-01-01

    Roč. 66, č. 3 (2011), s. 470-476 ISSN 0006-3088 Institutional research plan: CEZ:AV0Z60870520; CEZ:AV0Z60660521 Keywords : Chenopodium album * growth stimulation * humic substance * lignite * seed germination Subject RIV: EH - Ecology, Behaviour Impact factor: 0.557, year: 2011

  17. Photodegradation of bisphenol A in simulated lake water containing algae, humic acid and ferric ions

    Energy Technology Data Exchange (ETDEWEB)

    Peng Zhang' e [School of Resources and Environmental Science, Wuhan University, Wuhan 430079 (China)]. E-mail: zhepeng@126.com; Wu Feng [School of Resources and Environmental Science, Wuhan University, Wuhan 430079 (China)]. E-mail: fengwu@whu.edu.cn; Deng Nansheng [School of Resources and Environmental Science, Wuhan University, Wuhan 430079 (China)]. E-mail: nsdengwhu@163.com

    2006-12-15

    The photodegradation of bisphenol A (BPA), a suspected endocrine disruptor (ED), in simulated lake water containing algae, humic acid and Fe{sup 3+} ions was investigated. Algae, humic acid and Fe{sup 3+} ions enhanced the photodegradation of BPA. Photodegradation efficiency of BPA was 36% after 4 h irradiation in the presence of 6.5 x 10{sup 9} cells L{sup -1} raw Chlorella vulgaris, 4 mg L{sup -1} humic acid and 20 {mu}mol L{sup -1} Fe{sup 3+}. The photodegradation efficiency of BPA was higher in the presence of algae treated with ultrasonic than that without ultrasonic. The photodegradation efficiency of BPA in the water only containing algae treated with ultrasonic was 37% after 4 h irradiation. The algae treated with heating can also enhance the photodegradation of BPA. This work helps environmental scientists to understand the photochemical behavior of BPA in lake water. - Algae, humic acid and ferric ions can induce the photodegradation of bisphenol A in an aqueous environment.

  18. Aqueous photocatalytic oxidation of lignin and humic acids with supported TiO2

    Directory of Open Access Journals (Sweden)

    Elina Portjanskaja

    2006-01-01

    Full Text Available The photocatalytic oxidation (PCO of UV-irradiated aqueous solutions containing humic acids and lignin was studied. The photocatalyst TiO2 was attached to buoyant hollow glass microspheres and glass plates. A maximum oxidation efficiency as low as 1.1 and 2.54 mg W−1h−1 for humic acids and lignin, respectively, was achieved in neutral and alkaline media with 25 gm−2 of the buoyant catalyst. In acidic media, efficiency was even lower. The photocatalytic efficiency with the photocatalyst attached to glass plates was about 3 to 4 times higher than that for the buoyant catalyst. Ferrous ions added to acidic solutions did not increase the rate of PCO of humic acids. However the addition of Fe2+ ions, up to 0.05 mM, to the lignin solution leads to a dramatic increase, about 25%, in PCO efficiency. A further increase in ferrous ion concentration results in a decrease in the PCO efficiency of lignin. Proceeding most likely by a radical mechanism, the efficiency of PCO of humic acids did not benefit from an excessive presence of hydroxyl radical promoters, such as hydrogen peroxide, although the reaction rate increased. However, PCO of lignin in the acidic medium, where OH.-radical formation is suppressed, benefited from the introduction of hydrogen peroxide due to promoted radical formation.

  19. Aqueous photocatalytic oxidation of lignin and humic acids with supported TiO 2

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available The photocatalytic oxidation (PCO of UV-irradiated aqueous solutions containing humic acids and lignin was studied. The photocatalyst TiO 2 was attached to buoyant hollow glass microspheres and glass plates. A maximum oxidation efficiency as low as 1.1 and 2.54 mg W −1 h −1 for humic acids and lignin, respectively, was achieved in neutral and alkaline media with 25 gm −2 of the buoyant catalyst. In acidic media, efficiency was even lower. The photocatalytic efficiency with the photocatalyst attached to glass plates was about 3 to 4 times higher than that for the buoyant catalyst. Ferrous ions added to acidic solutions did not increase the rate of PCO of humic acids. However the addition of Fe 2+ ions, up to 0.05 mM, to the lignin solution leads to a dramatic increase, about 25%, in PCO efficiency. A further increase in ferrous ion concentration results in a decrease in the PCO efficiency of lignin. Proceeding most likely by a radical mechanism, the efficiency of PCO of humic acids did not benefit from an excessive presence of hydroxyl radical promoters, such as hydrogen peroxide, although the reaction rate increased. However, PCO of lignin in the acidic medium, where OH.-radical formation is suppressed, benefited from the introduction of hydrogen peroxide due to promoted radical formation.

  20. Impact of the application of humic acid and sodium nitroprusside on ...

    African Journals Online (AJOL)

    Daniel

    agricultural production, the use of humic acid can also accelerate remediation of contaminated soil by heavy metals (Xu et al., 2010). In the case of the SNP the number of studies that have examined the exogenous NO effects on reducing heavy metal toxicity in plants has increased. Application of SNP under different heavy ...

  1. Humic Acid-Like Material from Sewage Sludge Stimulates Culture Growth of Ectomycorrhizal Fungi in Vitro

    Czech Academy of Sciences Publication Activity Database

    Hršelová, Hana; Soukupová, Lucie; Gryndler, Milan

    2007-01-01

    Roč. 52, č. 6 (2007), s. 627-630 ISSN 0015-5632 R&D Projects: GA ČR GA526/06/0540 Institutional research plan: CEZ:AV0Z50200510 Keywords : ectomycorrhizal basidiomycetes * sewage sludge * humic-acid-like materials Subject RIV: EE - Microbiology, Virology Impact factor: 0.989, year: 2007

  2. Preparative yield and properties of humic acids obtained by sequential alkaline extractions

    Science.gov (United States)

    Kholodov, V. A.; Yaroslavtseva, N. V.; Konstantinov, A. I.; Perminova, I. V.

    2015-10-01

    The preparative yield, composition, and structure of humic acids obtained by sequential alkaline extractions from two soils (a soddy-podzolic soil under forest and a typical chernozem in treatment with permanent black fallow of a long-term experiment since 1964) have been studied. The preparative yield of humic acids from the first extraction is 0.40 and 0.94% for the soddy-podzolic soil (Retisols) and the chernozem, respectively. The preparative yield from the second extraction is lower by several times, and the yield from the third extraction is lower by an order of magnitude. The study of the obtained preparations by elemental analysis, gel-permeation chromatography, and 13C NMR spectroscopy has shown insignificant changes in the elemental, molecular-weight, and structural-group composition of humic acids among the extractions. It has been supposed that this is related to the soil features: typical climatic factors for the formation of soil subtype in the case of soddy-podzolic soil and the land use in the long-term experiment in the case of typical chernozem. It has been concluded that that a single extraction is sufficient for the separation of humic acids and the preparation of a representative sample.

  3. Influence of humic acid on algal uptake and toxicity of ionic silver.

    Science.gov (United States)

    Chen, Zhongzhi; Porcher, Céline; Campbell, Peter G C; Fortin, Claude

    2013-08-06

    The biogeochemical cycle of silver has been profoundly disturbed by various anthropogenic activities. To better understand the relationship among silver speciation, bioavailability, and toxicity in freshwaters, we have studied the short-term uptake of silver by two species of green algae, Chlamydomonas reinhardtii and Pseudokirchneriella subcapitata, in the presence or absence of a well-characterized humic acid (Suwannee River Humic Acid, SRHA). The free Ag(+) concentrations in the exposure solutions were determined using an equilibrium ion-exchange technique. According to the biotic ligand model, for a given free metal ion concentration, metal uptake should remain the same in the presence or absence of humic acid. However, short-term silver uptake in the presence of SRHA was greater than anticipated on the basis of free Ag(+) concentration. Subsequent determination of silver subcellular distribution revealed that significantly more silver was present in the "cell debris" fraction (known to contain the cell wall and fragmented membranes) in the presence of SRHA than in its absence. Finally, this increase in silver uptake in the presence of humic acid did not result in decreased algal growth. These results suggest that the increase in silver uptake observed in the presence of SRHA is surface-bound, not truly internalized.

  4. Fluorescence spectroscopy: a tool to characterize humic substances in soil colonized by microorganisms?

    Czech Academy of Sciences Publication Activity Database

    Řezáčová, Veronika; Gryndler, Milan

    2006-01-01

    Roč. 51, č. 3 (2006), s. 215-221 ISSN 0015-5632 R&D Projects: GA ČR GA526/03/0188 Institutional research plan: CEZ:AV0Z50200510 Keywords : fluorescence spectroscopy * humic substances * microorganism Subject RIV: EE - Microbiology, Virology Impact factor: 0.963, year: 2006

  5. Effects of calcium and humic acid treatment on the growth and ...

    African Journals Online (AJOL)

    Humic acid (HA) may facilitate plant growth by improving the nutrient uptake as well as through hormonal effects. Studies were conducted to investigate the effect of a mixture of calcium and HA on Oriental lily, which is sensitive to calcium deficiency. Two levels of Ca (3.5 and 7.0 meq/L) were combined with 500 mg/L HA ...

  6. A facile disposal of Bayer red mud based on selective flocculation desliming with organic humics.

    Science.gov (United States)

    Huang, Yanfang; Han, Guihong; Liu, Jiongtian; Wang, Wenjuan

    2016-01-15

    Humics flocculant was applied in the disposal of Bayer red mud based on selective flocculation desliming process. The parameters affecting selective flocculation behavior such as flocculant dosage, slurry pH and agitation intensity were studied. For flocculating mechanism analysis, the iron mineral and the flocs product were characterized by ζ-potential testing, settling experiments, optical microscope and SEM imaging. The results show that humics exhibits a good selective flocculation performance in the high alkaline pH range. With an optimal condition of 2% solid density, flocculant dosage 30 mg L(-1), Na2SiO3 dosage 200 mg L(-1), slurry pH 10.0 and agitation speed 1000 rpm, the recovery of iron minerals of 86.25±1.31%, the iron grade of concentrate of 61.12±0.10%, the separation index of 0.69±0.02 can be obtained in the selective flocculation. It is found that the adsorption bridging of humics polymer dominates the selectively flocculating the iron minerals. Large flocs or aggregates with a better settling capacity are generated because of humics occurring. The maximum settling velocity of 38.23±1.51 m h(-1) is reached at pH 10. This work brings the easiness in directly recovering fine particle size of iron-bearing minerals from red mud. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Generic NICA-Donnan model parameters for metal-ion binding by humic substances

    NARCIS (Netherlands)

    Milne, C.J.; Kinniburgh, D.G.; Riemsdijk, van W.H.; Tipping, E.

    2003-01-01

    A total of 171 datasets of literature and experimental data for metal-ion binding by fulvic and humic acids have been digitized and re-analyzed using the NICA-Donnan model. Generic parameter values have been derived that can be used for modeling in the absence of specific metal-ion binding

  8. Interaction between Humic Acid and Lysozyme, Studied by Dynamic Light Scattering and Isothermal Titration Calorimetry

    NARCIS (Netherlands)

    Tan, Wen Feng; Koopal, Luuk K.; Norde, Willem

    2009-01-01

    Interactions of purified Aldrich humic acid (PAHA) with the protein lysozyme (LSZ) are studied with dynamic light scattering and isothermal titration calorimetry by mixing LSZ and PAHA at various mass ratios. In solution LSZ is positive and PAHA is negative at the investigated pH values. Up to

  9. Study of Metal-Humic Catalysts before and After the Gas Desulphurization Process Using Thermal Analysis

    Science.gov (United States)

    Szyszka, Danuta; Wieckowska, Jadwiga

    2017-12-01

    The study of metal-humic catalysts before and after the SO2 conversion has been carried out using thermal analysis. The thermogravimetric analysis and differential thermal analysis has been carried out using Perkin-Elmer TGA 7 and DTA 7 equipment in an argonic atmosphere. The heating rate of samples in the DTA was 10 °C/min., and in the TGA 40 °C/min. The following catalysts have been chosen for analysis: H-Pb2+/450 °C, H-B/450 °C, H-Sn2+/450 °C, H-Ce 4+. The study of metal-humic catalysts using thermal analysis has shown that, in the DTA curves of studied catalysts before SO2 conversion, endothermic peaks related to decomposition of metal carbonates, melting of metals or decomposition of metal-humic bonding. In the DTA curves after the SO2 conversion process, there are additional endothermic peaks related to the presence of sulphur in the metal-humic compounds and to thermal decomposition of those bonds.

  10. Agronomic performance and soil chemical attributes in a banana tree orchard fertigated with humic substances

    Directory of Open Access Journals (Sweden)

    Diego Magalhães de Melo

    2016-12-01

    Full Text Available Fertigation with humic substances products has been adopted in commercial banana tree plantations. However, there are few studies on the procedure to confirm its technical feasibility. This study aimed at assessing the effects of fertigation with humic substances on the chemical attributes of a Dystric Densic Xantic Ferralsol cultivated with the 'BRS Princesa' banana tree cultivar and on the agronomic performance of the orchard. The experiment was conducted using a randomized blocks design, with six treatments and four replications. Treatments consisted of a monthly application of humic substances doses based on the commercially recommended reference dose for the banana plantation (12.09 kg ha-1 cycle-1. The doses used were equivalent to percentages of the reference dose (100 %, 150 %, 200 %, 250 % and 300 %, in addition to the control. No significant effects of the fertigation with humic substances that could justify the use of the product at the doses assessed were observed on the soil chemical attributes, banana growth and yield.

  11. Humic acid and enzymes in canola-based broiler diets: Effects on ...

    African Journals Online (AJOL)

    NWUUser

    2017-10-17

    Oct 17, 2017 ... Abstract. The objective of the study was to investigate the effects of dietary inclusion of humic acid and enzymes on bone development, histomorphology of internal organs and the incidence of rickets in broiler chickens fed canola-based diets. In the study, Cobb 500 broiler chicks were used and the ...

  12. Application of HPLC capacity coefficients to characterize the sorption of polycyclic aromatic compounds to humic acid

    DEFF Research Database (Denmark)

    Nielsen, T.; Helweg, C.; Siigur, K.

    1997-01-01

    The sorption coefficients to humic acid of 46 PAC having a wide range in polarity were compared with the capacity coefficients of the PAC to a non-polar HPLC column material (ODS) and a polar one (Diol). It is shown that polar interactions contribute to the sorption of polar PAC in addition...

  13. Molecular Features of Humic Acids and Fulvic Acids from Contrasting Environments

    NARCIS (Netherlands)

    Schellekens, Judith; Buurman, Peter; Kalbitz, Karsten; Zomeren, van Andre; Vidal-Torrado, Pablo; Cerli, Chiara; Comans, Rob N.J.

    2017-01-01

    Insight in the molecular structure of humic acid (HA) and fulvic acid (FA) can contribute to identify relationships between their molecular properties, and further our quantitative abilities to model important organic matter functions such as metal complexation and association with mineral

  14. Humification and Humic Acid Composition of Suspended Soil in Oligotrophous Environments in South Vietnam

    Directory of Open Access Journals (Sweden)

    E. V. Abakumov

    2018-01-01

    Full Text Available Humification is considered to be a global process that is implemented in soils and organic sediments and also in natural water and air. The term “suspended soils” has become increasingly common in recent years. Suspended soils are defined as the part of the organic matter that has not undergone the full decomposition process and has not turned into the humus of terrestrial soils. Suspended soils were shown to contain higher total nitrogen, phosphorus, and potassium contents than the forest soil, but the moisture content in suspended soils was significantly lower. Our study of the structural composition of humic substances in suspended soils was conducted with an aim of evaluating the humification rates and structural composition of humic acids in the suspended soil in tropical forests of South Vietnam. Soil samples from three selected areas were investigated: the soil under phorophytes (mineral soil presented by samples of topsoil of the typical dry savanna landscape and two soils from epiphytous formations. Samples were collected from savanna-type sparse communities, located on oligotrophous plains in Phú Quốc Island (South Vietnam in 2015. General properties of the soil and the elemental composition of suspended soils were determined, and the humic substance chemical composition was evaluated using solid state 13C-NMR. Data obtained showed that the pH of the soils under phorophytes was higher than in the suspended soils; basal respiration did not tend to change indices between soils under phorophytes and suspended soils, but the suspended soil was less enriched by nitrogen than the soil under phorophytes. This can be related to the total amount of organic matter exposed to humification in various soils and to the presence of an essential portion of mineral particles in the soil under phorophytes. Data on elemental composition of the humic acids (HAs indicated that one method of humification is implemented in all three soils that were

  15. Influence of humic substances on plant-microbes interactions in the rhizosphere

    Science.gov (United States)

    Puglisi, Edoardo; Pascazio, Silvia; Spaccini, Riccardo; Crecchio, Carmine; Trevisan, Marco; Piccolo, Alessandro

    2013-04-01

    Humic substances are known to play a wide range of effects on the physiology of plant and microbes. This is of particular relevance in the rhizosphere of terrestrial environments, where the reciprocal interactions between plants roots, soil constituents and microorganisms strongly influence the plants acquisition of nutrients. Chemical advances are constantly improving our knowledge on humic substances: their supra-molecular architecture, as well as the moltitude of their chemical constituents, many of which are biologically active. An approach for linking the structure of humic substances with their biological activity in the rhizosphere is the use of rhizoboxes, which allow applying a treatment (e.g., an amendment with humic substances) in an upper soil-plant compartment and take measurements in a lower isolated rhizosphere compartment that can be sampled at desired distances from the rhizoplane. This approach can be adopted to assess the effects of several humic substances, as well as composted materials, on maize plants rhizodeposition of carbon, and in turn on the structure and activity of rhizosphere microbial communities. In order to gain a complete understanding of processes occurring in the complex soil-plant-microorganisms tripartite system, rhizobox experiments can be coupled with bacterial biosensors for the detection and quantification of bioavailable nutrients, chemical analyses of main rhizodeposits constituents, advanced chemical characterizations of humic substances, DNA-fingerprinting of microbial communities, and multivariate statistical approaches to manage the dataset produced and to infer general conclusions. By such an approach it was found that humic substances are significantly affecting the amount of carbon deposited by plant roots. This induction effect is more evident for substances with more hydrophobic and complex structure, thus supporting the scientific hypothesis of the "microbial loop model", which assumes that plants feed

  16. Effect of Lime, Humic Acid and Moisture Regime on the Availability of Zinc in Alfisol

    Directory of Open Access Journals (Sweden)

    Sushanta Kumar Naik

    2007-01-01

    Full Text Available Lime and humic acid application can play an important role in the availability of zinc in paddy soils. We conducted laboratory incubation experiments on a rice growing soil (Alfisol to determine the effect of lime, humic acid and different moisture regimes on the availability of Zn. Addition of half doses of liming material (powdered lime stone recorded highest values of DTPA-Zn followed by no lime and 100% of lime requirement throughout the incubation period. With the progress of incubation, DTPA-Zn increased slightly during the first week and then decreased thereafter. The highest DTPA-extractable Zn content of 2.85 mg/kg was found in the treatment Zn10 L1/2 at 7 days of incubation, showing 17.3 % increase in DTPA-Zn content over its corresponding treatment of Zn alone (Zn10L0. The DTPA-Zn concentration increased with the application of humic acid compared with no humic acid throughout 35 days of the incubation period and the peak value obtained was 3.12 mg/kg in the treatment Zn10 HA2 at 14 days after incubation, showing 50 % increase in Zn content over its corresponding treatment of Zn alone (Zn10HA0. The application of 0.2% humic acid compared with 0.1% resulted in greater increase in DTPA-Zn concentration in soil application. During the 35 days of incubation, highest values of DTPA-Zn were recorded in soil maintained at saturated compared to water logged conditions. However, under alternate wetting and drying condition the DTPA-Zn content gradually decreased up to 21 days and thereafter increased slowly.

  17. Cross polarization, magic-angle spinning /sup 13/C nuclear magnetic resonance spectroscopy of soil humic fractions

    Energy Technology Data Exchange (ETDEWEB)

    Saiz-Jimenez, C.; Hawkins, B.L.; Maciel, G.E.

    1986-01-01

    Cross polarization, magic-angle spinning /sup 13/C nuclear magnetic resonance spectroscopy was used to characterize humic fractions isolated from different soils. The humic acid fractions are more aromatic than the humin fractions, probably due to the higher polysaccharide content of humins. However, fulvic acid fractions are more aromatic than the corresponding humic acid and humin fractions. These results can be interpreted in terms of the isolation procedure, because the high affinity of Polyclar AT for phenols results in higher aromaticities as compared with other isolation methods (e.g. charcoal).

  18. 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

  19. 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.

  20. Dissolved particulate and sedimentary humic acids in the mangroves and estuarine ecosystem of Goa, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Sardessai, S.

    Highest concentration of humic acids in all the three forms (dissolved, particulate and sedimentary) was found in the monsoon (June-September) when the salinity was minimum while the lowest concentrations was observed in the premonsoon (February...

  1. Decolorization of humic acids and alkaline lignin derivative by an anamorphic Bjerkandera adusta E59 strain isolated from soil

    Energy Technology Data Exchange (ETDEWEB)

    Kornillowicz-Kowalska, T.; Ginalska, G.; Belcarz, A.; Iglik, H. [University of Life Sciences, Lublin (Poland). Dept. of Microbiology

    2008-07-01

    An anamorphic Bjerkandera adusta R59 strain, isolated from soil, was found to decolorize post-industrial lignin alkaline fraction, humic acids isolated from two kinds of soil and from brown coal. The drop of methoxyphenolic compound levels in liquid B. adusta cultures containing lignin or humic acids was correlated with decolorization of studied biopolymers, which suggests their partial biodegradation. It was shown that this process was Coupled with the induction of secondary metabolism (idiophase), and highest peroxidase activity in culture medium and appearance of aerial mycelium. Decolorization of lignin and humic acids from lessive soil and brown coal depended on glucose presence (cometabolism). Decolorization of humic acid from chernozem was related partially to adsorption by fungal mycelium.

  2. 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.

    The combination of ultrafiltration technique with competing ligand exchange method provides a better understanding of interactions between Ni and different molecular weight fractions of humic acid (HA) at varying pH in aquatic environment...

  3. Assessing the Effects of Soil Humic and Fulvic Acids on Germination and Early Growth of Native and Introduced Grass Varieties

    National Research Council Canada - National Science Library

    Senesi, Nicola

    2007-01-01

    The presence of humic acid (HA) generally affects positively and at various extent the germination and early growth of all varieties examined but in some cases negative effects are measured on the early growth...

  4. 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...

  5. Influence of littoral periphyton on whole-lake metabolism relates to littoral vegetation in humic lakes.

    Science.gov (United States)

    Vesterinen, Jussi; Devlin, Shawn P; Syväranta, Jari; Jones, Roger I

    2017-12-01

    The role of littoral habitats in lake metabolism has been underrated, especially in humic lakes, based on an assumption of low benthic primary production (PP) due to low light penetration into water. This assumption has been challenged by recent recognition of littoral epiphyton dominance of whole-lake PP in a small highly humic lake and of epiphyton as an important basal food source for humic lake biota. However, as these studies have mostly concerned single lakes, there is a need to test their wider generality. We studied the whole-lake PP and community respiration (CR) in eight small humic lakes in southern Finland during July 2015 using 14 C incorporation to measure pelagic PP and the changes in dissolved inorganic carbon in light and dark in situ incubations to measure CR and littoral PP by epiphyton. Changes in O 2 concentration in both pelagic and littoral surface water were measured periodically from each lake and, additionally, continuously with a data logger from one lake during the study period. The results revealed that the littoral dominated whole-lake net primary production (NPP) in five of the eight lakes, which was supported by observed O 2 supersaturation in the littoral surface water in most of the lakes. Calculated pelagic:littoral ratios by area correlated negatively with both littoral NPP and littoral contribution to whole-lake NPP. Moreover, there was a significant positive relationship between littoral proportion of whole-lake NPP and the fraction of lake surface area covered by littoral aquatic vegetation. This demonstrates that increased aquatic littoral vegetation cover increases the overall importance of the littoral to whole-lake PP in highly humic lakes. Littoral NPP also correlated strongly with littoral O 2 saturation, and the continuously measured O 2 revealed substantial temporal variation in O 2 saturation, particularly in the littoral zone. Whole-lake gross primary production:community respiration (GPP:CR) ratios revealed that

  6. 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

  7. Organic Matter Fractions and Quality of the Surface Layer of a Constructed and Vegetated Soil After Coal Mining. I - Humic Substances and Chemical Characterization

    Directory of Open Access Journals (Sweden)

    Otávio dos Anjos Leal

    2015-06-01

    Full Text Available After open coal mining, soils are “constructed”, which usually contain low levels and quality of organic matter (OM. Therefore, the use of plant species for revegetation and reclamation of degraded areas is essential. This study evaluated the distribution of carbon (C in the chemical fractions as well as the chemical characteristics and humification degree of OM in a soil constructed after coal mining under cultivation of perennial grasses. The experiment was established in 2003 with the following treatments: Hemarthria altissima (T1, Paspalum notatum (T2, Cynodon dactilon (T3, Urochloa brizantha (T4, bare constructed soil (T5, and natural soil (T6. In 2009, soil samples were collected from the 0.00-0.03 m layer and the total organic carbon stock (TOC and C stock in the chemical fractions: acid extract (CHCl, fulvic acid (CFA, humic acid (CHA, and humin (CHU were determined. The humic acid (HA fraction was characterized by infrared spectroscopy and the laser-induced fluorescence index (ILIF of OM was also calculated. After six years, differences were only observed in the CHA stocks, which were highest in T1 (0.89 Mg ha-1 and T4 (1.06 Mg ha-1. The infrared spectra of HA in T1, T2 and T4 were similar to T6, with greater contribution of aliphatic organic compounds than in the other treatments. In this way, ILIF decreased in the sequence T5>T3>T4>T1>T2>T6, indicating higher OM humification in T3 and T5 and more labile OM in the other treatments. Consequently, the potential of OM quality recovery in the constructed soil was greatest in treatments T1 and T4.

  8. 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.

  9. 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...... side missing structural elements in the models can be suggested. A number of proposed structures for humic and fulvic acids are discussed based on the above analysis....

  10. Effects of humic acid-based buffer + cation on chemical characteristics of saline soils and maize growth

    Directory of Open Access Journals (Sweden)

    W. Mindari

    2014-10-01

    Full Text Available Humic acid is believed to maintain the stability of the soil reaction, adsorption / fixation / chelate of cation, thereby increasing the availability of water and plant nutrients. On the other hand, the dynamics of saline soil cation is strongly influenced by the change of seasons that disrupt water and plant nutrients uptake. This experiment was aimed to examine the characteristics of the humic acid from compost, coal, and peat and its function in the adsorption of K+ and NH4+ cations, thus increasing the availability of nutrients and of maize growth. Eighteen treatments consisted of three humic acid sources (compost, peat and coal, two cation additives (K+ and NH4+, and three doses of humic acid-based buffer (10, 20, and 30 g / 3kg, were arranged in a factorial completely randomized with three replicates. The treatments were evaluated against changes in pH, electric conductivity (EC, cation exchange capacity (CEC, chlorophyll content, plant dry weight and plant height. The results showed that the addition of K+ and NH4+ affected pH, CEC, K+, NH4+, and water content of the buffer. Application of humic acid-based buffer significantly decreased soil pH from > 7 to about 6.3, decreased soil EC to 0.9 mS / cm, and increased exchangeable Na from 0.40 to 0.56 me / 100g soil, Ca from 15.57 to 20.21 me/100 g soil, Mg from 1.76 to 6.52 me/100 g soil, and K from 0.05-0.51 me / 100g soil. Plant growth (plant height, chlorophyll content, leaf area, and stem weight at 35 days after planting increased with increasing dose of humic acid. The dose of 2.0g peat humic acid + NH4+ / 3 kg of soil or 30g peat humic acid + K+ / 3 kg of oil gave the best results of maize growth.

  11. 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.

  12. Removal of 2,4-dichlorophenoxyacetic acid in aqueous solution by pulsed corona discharge treatment: Effect of different water constituents, degradation pathway and toxicity assay.

    Science.gov (United States)

    Singh, Raj Kamal; Philip, Ligy; Ramanujam, Sarathi

    2017-10-01

    A multiple pin-plane corona discharge reactor was used to generate plasma for the degradation of 2,4 dichlorophenoxyacetic acid (2,4-D) from the aqueous solution. The 2,4-D of concentration 1 mg/L was completely removed within 6 min of plasma treatment. Almost complete mineralization was achieved after the treatment time of 14 min for a 2,4-D concentration of 10 mg/L. Effects of different water constituents such as carbonates, nitrate, sulphate, chloride ions, natural organic matter (humic acids) and pH on 2,4-D degradation was studied. A significant antagonistic effect of carbonate and humic acid was observed, whereas, the effects of other ions were insignificant. A higher first order rate constant of 1.73 min -1 was observed, which was significantly decreased in the presence of carbonate ions and humic acids. Also, a higher degradation of 2,4-D was observed in acidic pH conditions. Different 2,4-D intermediates were detected and the degradation pathway of 2,4-D in plasma treatment process was suggested. The toxicity of 10 mg/L 2,4-D was completely eradicated after 10 min of plasma treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. The Effect of Mycorrhizal Fungi and Humic Acid on Yield and Yield Components of Sunflower

    Directory of Open Access Journals (Sweden)

    Hamideh Veysi

    2017-08-01

    Full Text Available Introduction Cultivated sunflower is one of the largest oilseed crops in the world. Sunflower seed is the third largest source of vegetable oil worldwide, following soybean and canola. Nitrogen is one of the most important elements for crops to achieve optimum yields and quality. Phosphorus (P, next to nitrogen, is often the most limiting nutrient for crop and forage production. Phosphorus availability is controlled by three primary factors: soil pH, amount of organic matter and plant species (Reddy et al., 2003. Arbuscular mycorrhizal fungi are one of the most important microorganisms in majority of the undamaged soils so that about 70% of the soil microbial biomass is formed by the mycelium of these fungi. Mycorrhizal association promotes plant absorption of scarce or immobile minerals, especially phosphorus, resulting in enhanced plant growth. Humic acids are dark brown to black, and are soluble in waterunder neutral and alkaline conditions. They are complex aromatic macromolecules with amino acid, amino sugar, peptide and aliphatic compounds linked to the aromatic groups. Humic acid contains nitrogen, phosphorous, calcium, magnesium, sulphur, copper and zinc (Subramanian et al., 2009. Materials and methods Experiment was conducted as split plot factorial based on randomized block design with three replications in 2011-2012. The main plots consisted of nitrogen and phosphorus application levels (zero percent or no chemical fertilizer application, 50% equivalent to 37.5 kg.ha-1 urea + 25 kg.ha-1 super phosphate triple and 100% equivalent to 75 kg.ha-1 urea + 25 kg.ha-1 super phosphate triple. Two species of mycorrhizal include (G. mosseae and (G. interaradices with three levels of humic acid (0, 8 and 16 kg.ha-1 were placed in subplots. The measured traits were: plant height, seed number per head, head diameter, seed oil content, thousand seed weight and seed yield. The data were analyzed using the Mstat-C statistical software. Mean comparison

  14. The Effect of Mycorrhizal Fungi and Humic Acid on Yield and Yield Components of Sunflower

    Directory of Open Access Journals (Sweden)

    Hamideh Veysi

    2017-03-01

    Full Text Available Introduction Cultivated sunflower is one of the largest oilseed crops in the world. Sunflower seed is the third largest source of vegetable oil worldwide, following soybean and canola. Nitrogen is one of the most important elements for crops to achieve optimum yields and quality. Phosphorus (P, next to nitrogen, is often the most limiting nutrient for crop and forage production. Phosphorus availability is controlled by three primary factors: soil pH, amount of organic matter and plant species (Reddy et al., 2003. Arbuscular mycorrhizal fungi are one of the most important microorganisms in majority of the undamaged soils so that about 70% of the soil microbial biomass is formed by the mycelium of these fungi. Mycorrhizal association promotes plant absorption of scarce or immobile minerals, especially phosphorus, resulting in enhanced plant growth. Humic acids are dark brown to black, and are soluble in waterunder neutral and alkaline conditions. They are complex aromatic macromolecules with amino acid, amino sugar, peptide and aliphatic compounds linked to the aromatic groups. Humic acid contains nitrogen, phosphorous, calcium, magnesium, sulphur, copper and zinc (Subramanian et al., 2009. Materials and methods Experiment was conducted as split plot factorial based on randomized block design with three replications in 2011-2012. The main plots consisted of nitrogen and phosphorus application levels (zero percent or no chemical fertilizer application, 50% equivalent to 37.5 kg.ha-1 urea + 25 kg.ha-1 super phosphate triple and 100% equivalent to 75 kg.ha-1 urea + 25 kg.ha-1 super phosphate triple. Two species of mycorrhizal include (G. mosseae and (G. interaradices with three levels of humic acid (0, 8 and 16 kg.ha-1 were placed in subplots. The measured traits were: plant height, seed number per head, head diameter, seed oil content, thousand seed weight and seed yield. The data were analyzed using the Mstat-C statistical software. Mean comparison

  15. The Investigation of Electron Beam Catalytical Oxidation Process Efficiency with Potassium Persulfate in Removal Humic Acid from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    MT Ghaneian

    2015-05-01

    Results: Based on the results, changes in pH had little effect on the Humic acid removal efficiency. The average, with increasing of pH from 4 to 10, the removal efficiency of humic acid from 72.59% to 73.36% increased, respectively. The results showed that increasing of the dose from 1 to 15 kGy, humic acid removal efficiency increases. Based on results by increasing of persulfate concentration, the removal efficiency increased so that with increasing of concentration of potassium persulfate from 0.1 to 0.5 mmol/100cc, removal efficiency from 69.43% to 83.82% was increased. Kinetic experiments showed that the decomposition of humic acid by electron beam radiation followed the second-order kinetic. Conclusion: The data from this study showed that the aqueous solution containing acid Humic is decomposed effectively by electron beams irradiation. Addition of potassium persulfate can be have significant improvements in removal efficiency of humic acid in the presence of electron beam.

  16. Structure and catalytic activities of ferrous centers confined on the interface between carbon nanotubes and humic acid

    Science.gov (United States)

    Wang, Bing; Zhou, Xiaoyan; Wang, Dongqi; Yin, Jun-Jie; Chen, Hanqing; Gao, Xingfa; Zhang, Jing; Ibrahim, Kurash; Chai, Zhifang; Feng, Weiyue; Zhao, Yuliang

    2015-01-01

    Preparation of heterogeneous catalysts with active ferrous centers is of great significance for industrial and environmental catalytic processes. Nanostructured carbon materials (NCM), which possess free-flowing π electrons, can coordinate with transition metals, provide a confinement environment for catalysis, and act as potential supports or ligands to construct analogous complexes. However, designing such catalysts using NCM is still seldom studied to date. Herein, we synthesized a sandwich structured ternary complex via the coordination of Fe-loaded humic acid (HA) with C&z.dbd;C bonds in the aromatic rings of carbon nanotubes (CNTs), in which the O/N-Fe-C interface configuration provides the confinement environment for the ferrous sites. The experimental and theoretical results revealed octahedrally/tetrahedrally coordinated geometry at Fe centers, and the strong hybridization between CNT C π* and Fe 3d orbitals induces discretization of the atomic charges on aromatic rings of CNTs, which facilitates O2 adsorption and electron transfer from carbon to O2, which enhances O2 activation. The O2 activation by the novel HA/Fe-CNT complex can be applied in the oxidative degradation of phenol red (PR) and bisphenol A (BPA) in aqueous media.Preparation of heterogeneous catalysts with active ferrous centers is of great significance for industrial and environmental catalytic processes. Nanostructured carbon materials (NCM), which possess free-flowing π electrons, can coordinate with transition metals, provide a confinement environment for catalysis, and act as potential supports or ligands to construct analogous complexes. However, designing such catalysts using NCM is still seldom studied to date. Herein, we synthesized a sandwich structured ternary complex via the coordination of Fe-loaded humic acid (HA) with C&z.dbd;C bonds in the aromatic rings of carbon nanotubes (CNTs), in which the O/N-Fe-C interface configuration provides the confinement environment for the

  17. Effect of exposure to sunlight and phosphorus-limitation on bacterial degradation of coloured dissolved organic matter (CDOM) in freshwater

    DEFF Research Database (Denmark)

    Kragh, Theis; Søndergaard, Morten; Tranvik, Lars

    2008-01-01

    This study reports on the interacting effect of photochemical conditioning of dissolved organic matter and inorganic phosphorus on the metabolic activity of bacteria in freshwater. Batch cultures with lake-water bacteria and dissolved organic carbon (DOC) extracted from a humic boreal river were...... to calculate bacterial growth efficiency (BGE). Bacterial degradation of DOC increased with increasing exposure to simulated sunlight and availability of phosphorus and no detectable growth occurred on DOC that was not pre-exposed to simulated sunlight. The outcome of photochemical degradation of DOC changed...

  18. Distribution of sorbed phenanthrene and pyrene in different humic fractions of soils and importance of humin.

    Science.gov (United States)

    Pan, B; Xing, B S; Liu, W X; Tao, S; Lin, X M; Zhang, X M; Zhang, Y X; Xiao, Y; Dai, H C; Yuan, H S

    2006-09-01

    Contributions of fulvic-humic acids (FA/HA) and humin (HM) to sorption of phenanthrene (PHE) and pyrene (PYR) in a soil were differentiated using a humic separation procedure after multi-concentration sorption experiments. It was found that the amount of solutes in FA/HA did not change significantly after 48 h, while that in HM increased continuously and slowly up to the end of the experimental period (720 h), indicating that HM was the main region for slow sorption. Based on the fitting results using Freundlich equation, it was found that nonlinearity of both solutes was greater in HM than in FA/HA, consistent with the sorption characteristics of individually extracted HA and HM in a separate experiment. The observed nonlinearity of the solute distribution was confirmed by using three other soil samples with organic carbon contents ranging from 0.7 to 7.9%. Distribution dynamics of PHE and PYR among various fractions were also discussed.

  19. Carbon humic acids and their use. Ugleguminovyye kisloty i ikh ispol'zovaniye

    Energy Technology Data Exchange (ETDEWEB)

    Zabramnyy, D.T.; Pobedonosteva, O.I.; Pobedonostseva, N.I.; Umarov, T.Z.

    1980-01-01

    This monograph gives the results of research into the molecular structure of humic acids; certain issues are examined of an applied nature; the data from experimental industrial tests are generalized. Data are generalized which involve questions of the use of humic acids in the form of multiple-ton product. In agriculture, they are used for producing final complex fertilizers and plant growth stimulators; in drilling technology, for improving drilling muds; in the cement industry, for lowering the moisture content of cement raw material sludges. Methods of modifying humates by sulfomethylation are described, and a method for producing coal-alkali reagents directly at drilling and cement firms, based on intensifying the process of interaction of coals with alkali solutions.

  20. Contributions of humic substances to the dissolved organic carbon pool in wetlands from different climates.

    Science.gov (United States)

    Watanabe, Akira; Moroi, Kunio; Sato, Hiromu; Tsutsuki, Kiyoshi; Maie, Nagamitsu; Melling, Lulie; Jaffé, Rudolf

    2012-08-01

    Wetlands are an important source of DOM. However, the quantity and quality of wetlands' DOM from various climatic regions have not been studied comprehensively. The relationship between the concentrations of DOM (DOC), humic substances (HS) and non-humic substances (NHS) in wetland associated sloughs, streams and rivers, in cool temperate (Hokkaido, Japan), sub-tropical (Florida, USA), and tropical (Sarawak, Malaysia) regions was investigated. The DOC ranged from 1.0 to 15.6 mg CL(-1) in Hokkaido, 6.0-24.4 mg CL(-1) in Florida, and 18.9-75.3 mg CL(-1) in Sarawak, respectively. The relationship between DOC and HS concentrations for the whole sample set was regressed to a primary function with y-intercept of zero (Pwetland soils, whereas the rate of the increase in the NHS supply has an upper limit which may be controlled by primary productivity. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. A multi-proxy study of sedimentary humic substances in the salt marsh of the Changjiang Estuary, China

    Science.gov (United States)

    Zhang, Yaoling; Du, Jinzhou; Zhao, Xin; Wu, Wangsuo; Peng, Bo; Zhang, Jing

    2014-12-01

    To better understand the origin, composition, and reactivity of sedimentary humic substances (HSs) in salt marshes in the Changjiang Estuary, HS samples were isolated from a sediment core that was collected from the Eastern Chongming salt marsh. Chemical and spectroscopic methods were used to analyze the features of these HSs. The results indicate that the studied HSs in the salt marsh sediments are mainly terrestrial-derived and that the sedimentary organic matter (SOM) in the top layer may contain more organic matter from marine sources and/or autochthonous materials due to the dramatic decreasing of the sediment supply as a result of damming. The degradation of labile carbohydrates and proteins and the preservation of refractory lignin components dominate the early diagenetic reactions of SOM in the salt marsh area. The average contents of the carboxylic groups in FAs and HAs are 11.64 ± 1.08 and 7.13 ± 0.16 meq/gC, and those of phenolic groups are 1.95 ± 0.13 and 2.40 ± 0.44 meq/gC, respectively. The content of carboxylic groups increased with increasing depth, while there were no obvious changes in the content of phenolic groups. The average concentration of total proton-binding sites is approximately 12.5 μmol/g sediment for the studied HSs. These values may provide insight into the migration and fate of HS-bound contaminants in sediments and the overlying sea water in the salt marsh areas of the Changjiang Estuary.

  2. Charge characteristics of humic and fulvic acids: comparative analysis by colloid titration and potentiometric titration with continuous pK-distribution function model.

    Science.gov (United States)

    Bratskaya, S; Golikov, A; Lutsenko, T; Nesterova, O; Dudarchik, V

    2008-09-01

    Charge characteristics of humic and fulvic acids of a different origin (inshore soils, peat, marine sediments, and soil (lysimetric) waters) were evaluated by means of two alternative methods - colloid titration and potentiometric titration. In order to elucidate possible limitations of the colloid titration as an express method of analysis of low content of humic substances we monitored changes in acid-base properties and charge densities of humic substances with soil depth, fractionation, and origin. We have shown that both factors - strength of acidic groups and molecular weight distribution in humic and fulvic acids - can affect the reliability of colloid titration. Due to deviations from 1:1 stoichiometry in interactions of humic substances with polymeric cationic titrant, the colloid titration can underestimate total acidity (charge density) of humic substances with domination of weak acidic functional groups (pK>6) and high content of the fractions with molecular weight below 1kDa.

  3. Sorption of metal ions on lignite and the derived humic substances

    Czech Academy of Sciences Publication Activity Database

    Havelcová, Martina; Mizera, Jiří; Sýkorová, Ivana; Pekař, M.

    2009-01-01

    Roč. 161, č. 1 (2009), s. 559-564 ISSN 0304-3894 R&D Projects: GA ČR GA105/05/0404 Institutional research plan: CEZ:AV0Z30460519; CEZ:AV0Z10480505 Keywords : lignite * humic substances * heavy metals Subject RIV: DH - Mining, incl. Coal Mining Impact factor: 4.144, year: 2009 www.elsevier.com/locate/hazmat

  4. 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.

  5. 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 ...

  6. Radiotracer study of europium interaction with humic acid using electrophoresis, ultrafiltration, and dialysis

    Czech Academy of Sciences Publication Activity Database

    Mizera, Jiří; Mizerová, Gabriela; Beneš, P.

    2005-01-01

    Roč. 263, č. 1 (2005), s. 75-80 ISSN 0236-5731. [International Conference on Methods and Applications of Radioanalytical Chemistry, MARC VI. Kailua-Kona, Hawaii, 07.04.2003-11.04.02003] Institutional research plan: CEZ:AV0Z10480505 Keywords : humic substances * europium * radiotracer technique Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.460, year: 2005

  7. 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.

  8. Study of humic acids by small-angle X-ray and neutron scattering

    International Nuclear Information System (INIS)

    Timchenko, A.; Trubetskaya, O.; Kihara, H.

    1999-01-01

    Humic acids are an important component of natural ecological system and represent a polydisperse complex of natural biopolymers with molecular masses from several to hundreds kilodaltons. They are both a source of organic compounds and a protector against anthropogenic pollutions of biosphere. The aim of the report is to underline some possibilities of small-angle X-ray and neutron scattering to study HA and their fractions. (author)

  9. Isotope evidence for soil organic carbon pools with distinct turnover rates—II. Humic substances

    OpenAIRE

    Lichtfouse, Eric; Dou, Sen; Houot, Sabine; Barriuso, Enrique

    1995-01-01

    International audience; Two experiments using 13C-enriched substrates have been undertaken to evaluate the relative turnover rates of the main pools of soil organic carbon namely bulk organic carbon, humin and humic acids. Firstly, soil organic matter was labelled naturally during a 5 year field experiment by cultivating Zea mays, a C4 plant, on a soil that had previously grown isotopically distincts C3 plants, e.g. wheat. Secondly, soil organic matter was labelled artificially with either Im...

  10. EFFECT OF HUMIC SUBSTANCES AND PROBIOTICS ON GROWTH PERFORMANCE AND MEAT QUALITY OF RABBITS

    Directory of Open Access Journals (Sweden)

    Vladimír Parkányi

    2012-04-01

    Full Text Available Normal 0 21 false false false MicrosoftInternetExplorer4  The aim of this work was determined effect of supplemental humic substances and probiotics on growth performance and meat quality of rabbits.  The growth performances were observed on two hundred and twelve growing rabbits assigned randomly by weight to two treatments. The treatments included: 1 Control group: in this group were rabbits fed with basal diet during all experiment (35th – 77th day, 2 experimental group: the animals were fed with basal diet+3kg/t humic substances – Humac Nature during whole experiment.  In this group was during fattening period (35th – 49th and 63rd – 70th days of age added to feed the probiotic preparation – Propoul (Lactobacillus fermentum CCM 7158 1x108 CFU 2 g per ten pieces. Body weight and feed intake were measured weekly in order to determine the average daily gain, average daily feed intake and gain/feed. The characteristics of meat quality were determined on twelve rabbit males at the age of 77 days, when the rabbits achieved average slaughter weight 2500g. Results of the whole experimental period showed that addition humic substances and probiotic preparation to the diet had positive effect (not significantly on intensity of growth live weight in the last phase of fattening period. The results of this study suggest that humic substances with probiotics might be utilized as a feed additive in the rabbit diet. It could not significantly improve growth performance and meat quality of rabbits.doi:10.5219/192 

  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. Distribution of sorbed phenanthrene and pyrene in different humic fractions of soils and importance of humin

    Energy Technology Data Exchange (ETDEWEB)

    Pan, B. [Laboratory for Earth Surface Processes, College of Environmental Sciences, Peking University, Beijing 100871 (China); Xing, B.S. [Department of Plant, Soil and Insect Sciences, University of Massachusetts, Stockbridge Hall, Amherst MA 01003-7245 (United States); Liu, W.X. [Laboratory for Earth Surface Processes, College of Environmental Sciences, Peking University, Beijing 100871 (China); Tao, S. [Laboratory for Earth Surface Processes, College of Environmental Sciences, Peking University, Beijing 100871 (China)]. E-mail: taos@urban.pku.edu.cn; Lin, X.M. [Laboratory for Earth Surface Processes, College of Environmental Sciences, Peking University, Beijing 100871 (China); Zhang, X.M. [Laboratory for Earth Surface Processes, College of Environmental Sciences, Peking University, Beijing 100871 (China); Zhang, Y.X. [Laboratory for Earth Surface Processes, College of Environmental Sciences, Peking University, Beijing 100871 (China); Xiao, Y. [Laboratory for Earth Surface Processes, College of Environmental Sciences, Peking University, Beijing 100871 (China); Dai, H.C. [Laboratory for Earth Surface Processes, College of Environmental Sciences, Peking University, Beijing 100871 (China); Yuan, H.S. [Laboratory for Earth Surface Processes, College of Environmental Sciences, Peking University, Beijing 100871 (China)

    2006-09-15

    Contributions of fulvic-humic acids (FA/HA) and humin (HM) to sorption of phenanthrene (PHE) and pyrene (PYR) in a soil were differentiated using a humic separation procedure after multi-concentration sorption experiments. It was found that the amount of solutes in FA/HA did not change significantly after 48 h, while that in HM increased continuously and slowly up to the end of the experimental period (720 h), indicating that HM was the main region for slow sorption. Based on the fitting results using Freundlich equation, it was found that nonlinearity of both solutes was greater in HM than in FA/HA, consistent with the sorption characteristics of individually extracted HA and HM in a separate experiment. The observed nonlinearity of the solute distribution was confirmed by using three other soil samples with organic carbon contents ranging from 0.7 to 7.9%. Distribution dynamics of PHE and PYR among various fractions were also discussed. - Humic fractionation after sorption experiment revealed that humin fraction is the main region for slow and nonlinear sorption of phenanthrene and pyrene.

  13. Enhanced PCBs sorption on biochars as affected by environmental factors: Humic acid and metal cations

    International Nuclear Information System (INIS)

    Wang Yu; Wang Lei; Fang Guodong; Herath, H.M.S.K.; Wang Yujun; Cang Long; Xie Zubin; Zhou Dongmei

    2013-01-01

    Biochar plays an important role in the behaviors of organic pollutants in the soil environment. The role of humic acid (HA) and metal cations on the adsorption affinity of polychlorinated biphenyls (PCBs) to the biochars in an aqueous medium and an extracted solution from a PCBs-contaminated soil was studied using batch experiments. Biochars were produced with pine needles and wheat straw at 350 °C and 550 °C under anaerobic condition. The results showed that the biochars had high adsorption affinity for PCBs. Pine needle chars adsorbed less nonplanar PCBs than planar ones due to dispersive interactions and separation. Coexistence of HA and metal cations increased PCBs sorption on the biochars accounted for HA adsorption and cation complexation. The results will aid in a better understanding of biochar sorption mechanism of contaminants in the environment. - Highlights: ► Application of the biochars for PCBs sorption was a new and effective way. ► The biochars had higher adsorption affinity for PCBs in the soil extracted solution. ► Pine needle chars adsorbed less nonplanar PCBs than planar ones. ► Coexisting humic acid or metal cations increased PCBs sorption on the biochars. - The biochars had higher adsorption affinity for PCBs in the extracted soil solution because coexisting humic acid and metal cations increased their sorption.

  14. 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.

  15. 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.

  16. 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.

  17. Modification of soil humic matter after 4 years of compost application.

    Science.gov (United States)

    Adani, Fabrizio; Genevini, Pierluigi; Ricca, Giuliana; Tambone, Fulvia; Montoneri, Enzo

    2007-01-01

    Two soil plots, 1 ha each, were amended yearly for 4 years, respectively, with 35.8 and 71.6 Mg ha(-1) yr(-1) of mature compost (CM) obtained from food and vegetable residues. The compost, amended soils, and a control soil plot after 4 years (S4), were analyzed for humin (HUC), humic acid (HAC), fulvic acid (FAC), and non-humic carbon (NHC) content. Compared to S4, the amended soil contained more humified C (HAC, FAC and HUC) and less NHC. Further evidence of the effect of compost on soil organic matter was obtained by the analysis of the humic acid (HA) fractions isolated from both the compost and the soils. These were characterized by elemental analyses and Diffuse Reflectance Infrared Fourier Transformed spectroscopy. The HAs isolated from CM and from S4 were significantly different. The HAs isolated from the amended plots were more similar to HA isolated from CM than to HA isolated from S4. The experimental data of this work indicate that the compost application may affect significantly the soil organic matter composition, and that the approach used in this work allows one to trace the fate of compost organic matter in soil.

  18. Covalent bonding of chloroanilines to humic constituents: Pathways, kinetics, and stability

    International Nuclear Information System (INIS)

    Kong, Deyang; Xia, Qing; Liu, Guoqiang; Huang, Qingguo; Lu, Junhe

    2013-01-01

    Covalent coupling to natural humic constituents comprises an important transformation pathway for anilinic pollutants in the environment. We systematically investigated the reactions of chlorine substituted anilines with catechol and syringic acid in horseradish peroxidase (HRP) catalyzed systems. It was demonstrated that although nucleophilic addition was the mechanism of covalent bonding to both catechol and syringic acid, chloroanilines coupled to the 2 humic constituents via slightly different pathways. 1,4-addition and 1,2-addition are involved to catechol and syringic acid, respectively. 1,4-addition showed empirical 2nd order kinetics and this pathway seemed to be more permanent than 1,2-addition. Stability experiments demonstrated that cross-coupling products with syringic acid could be easily released in acidic conditions. However, cross-coupling with catechol was relatively stable at similar conditions. Thus, the environmental behavior and bioavailability of the coupling products should be carefully assessed. -- Highlights: •Chloroanilines covalently coupled to humic constituents in HRP catalyzed processes, which facilitated their transformation. •MS technique was employed to analyze the coupling products and therefore elucidate the reaction pathways. •Chloroanilines couple to catechol and syringic acid via 1,4- and 1,2-nucleophilic addition pathways, respectively. •Cross-coupling products formed via 1,4-nucleophilic addition pathway were more stable than those via 1,2-addition pathway. -- Bound residues of chloroanilines formed via 1,2- and 1,4-nucleophilic addition pathways showed different stability

  19. Fouling of enhanced biological phosphorus removal-membrane bioreactors by humic-like substances.

    Science.gov (United States)

    Poorasgari, Eskandar; König, Katja; Fojan, Peter; Keiding, Kristian; Christensen, Morten Lykkegaard

    2014-12-01

    Fouling by free extracellular polymeric substances was studied in an enhanced biological phosphorus removal-membrane bioreactor. It was demonstrated that the free extracellular polymeric substances, primarily consisting of humic-like substances, were adsorbed to the membrane used in the enhanced biological phosphorus removal-membrane bioreactor plant. Infrared analyses indicated the presence of the humic-like substances on the membrane's active surface after filtration of the free extracellular polymeric substances suspension. Scanning electron microscopy showed the presence of a gel layer on the membrane surface after filtration of the free extracellular polymeric substances suspension. The gel layer caused a significant decline in water flux. This layer was not entirely removed by a backwashing, and the membrane's water flux could not be re-established. The membrane used in the enhanced biological phosphorus removal-membrane bioreactor plant showed infrared spectra similar to that fouled by the free extracellular polymeric substances suspension in the laboratory. Thus, the results of this study show the importance of humic-like substances in irreversible fouling of enhanced biological phosphorus removal-membrane bioreactor systems. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. 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.

  1. Thorium - humic compound interaction in the water of Morro do Ferro (Pocos de Caldas, MG, Brazil)

    International Nuclear Information System (INIS)

    Kuechler, I.L.

    1986-01-01

    Experimental procedures and results are presented on the determination of thorium and organic dissolved carbon (DOC) in natural waters (bore hole and surface waters) from the Morro de Ferro, a thorium - rare earth occurrence situated in the Pocos de Caldas Plateau in Minas Gerais (Brazil). A positive correlation between Th-232 and humic compounds content was abserved. Utilizing ultrafiltration techniques with Amicon membranes (XM-300, PM-10, UM-10 and YM-2), organic compounds with molecular weights above 1000 units were separated and concentrated from waters. Percolation waters rich in organic material concentrate DOC and Th-232 in the high molecular weight fractions ( > 10.000 MW units). Humic acid was separated from a percolation water sample and characterized by elemental and infrared spectroscopic analysis. The distribution coefficient of Th-232 between water and sediment was shown to be inversely correlated to DOC concentration, as reported by other authors for different environments. These results were also confirmed by laboratory experiments, which indicated additionally that low concentrations of humic acid ( [pt

  2. Effect of rhizobacteria inoculation and humic acid application on canola (Brassica napus L.) crop

    International Nuclear Information System (INIS)

    Ahmad, S.; Duar, I.; Solaimani, S.G.A.; Mahmood, S.

    2016-01-01

    This study investigated eco-friendly approach of utilizing plant growth promoting rhizobacteria (PGPR) and humic acid (HA) as bio-stimulants to improve the growth, yield and nutrition of canola (Brassica napus L.). In this study, we isolated 20 indigenous rhizobacterial strains that were subsequently screened and characterized for their plant growth promoting traits. After that one promising PGPR strain identified as Acinetobacter pittii by 16S rRNA gene sequencing was selected for field trial. The field experiment was conducted using RCB design with split-plot arrangement that was replicated four times. Three levels of humic acid (0, 10 and 20 kg ha-1) as main plot factor and two treatments of PGPR (with and without PGPR) as sub-plot factor were used. Data was recorded on plant height (cm), root dry matter plant-1, number of lateral root plant-1, number of pods plant-1, number of seeds pod-1, 1000 seed weight (g), seed yield(kg ha-1), oil content (%), nitrogen (N), phosphorus (P) and potassium (K) contents and uptake. For most of the above mentioned parameters, significant enhancement was observed with the increment of humic acid, and also PGPR treatments were better than their respective control treatments. Maximum values of these parameters were recorded for the interaction of 20 kg HA ha-1 with the PGPR strain. It can be concluded that integrated application of HA and PGPR is a better strategy to improve nutrition and yield of canola. (author)

  3. 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.

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

    International Nuclear Information System (INIS)

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

    2015-01-01

    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., P=O 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. - Highlights: • Noncovalent interactions between polyphosphate and HA were quantitatively evaluated. • Hydrogen bonding was the main driving force in the interaction between HA and poly-P. • The association played important roles in the environmental fate of poly-P in waters. - Stable polyP-HA complex would be formed through the noncovalent interactions and thus influence the poly-P fates in the natural environments.

  5. 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

  6. Reduction of Pu(V) and Np(V) by leonardite humic acids and their quinonoid-enriched derivatives

    International Nuclear Information System (INIS)

    Shcherbina, N.S.; Kalmykov, St.N.; Perminova, I.V.; Kovalenko, A.N.

    2005-01-01

    Full text of publication follows: Humic substances (HS) are natural poly-electrolytes ubiquitous in aquatic environment responsible for complexation of metal ions. The presence of phenolic and quinonoid moieties in the structure of HS provide for their ability to take part in redox interactions. Capability of HS to reduce plutonium from higher oxidation states (Pu(V) and Pu(VI)) to tetravalent state was reported in several studies. However, the disparate results were reported for Np(V). The contradicting results on the redox behavior of HS could originate from the structural differences of the humic materials tested, in particular, from varying content of the redox-active quinonoid moieties. To test this hypothesis, the goal of this research was to evaluate reducing performance of leonardite humic acids and of their quinonoid-enriched derivatives with respect to Pu(V) and Np(V). The quinonoid-enriched humic derivatives were obtained using the reaction of formaldehyde co-poly-condensation between parent humic material - leonardite humic acid - and model dihydroxybenzenes - hydroquinone, catechol and 1,4-benzoquinone. The humic material: quinonoid monomer ration of 1 g per 250 mg was used. The reduction of Np(V) was studied at micro- and macro-concentration level: 10 -7 M and 10 -4 M, respectively. In case of Pu(V) the concentration was about 10 -10 M. The HS concentrations varied from 1 to 100 ppm, while ionic strength was zero. All experiments were conducted in anaerobic conditions and in the darkness. The kinetics of Pu(V) reduction was studied using solvent extraction (TTA in toluene); to monitor Np(V) reduction two independent techniques were used: solvent extraction and VIS-NIR spectrophotometry. The latter allows measuring absorbance of NpO 2 + and Np-humate complexes at 981.3 and 987.4 nm, respectively. Fast reduction of Pu(V) by the parent humic material was observed and the reduction rate increased with a decrease in pH. In case of Np(V), there was no

  7. Removal of humic acid by a new type of electrical hollow-fiber microfiltration (E-HFMF)

    Science.gov (United States)

    Shang, Ran; Deng, Hui-ping; Hu, Jing-yi

    2010-11-01

    Low pressure membrane filtration, such as microfiltration, was widely used in the field of drinking water purification in the past few decades. Traditional microfiltration membranes are not efficient enough in the removal of natural organic matters (NOM) from raw water. Moreover, they tend to be fouled by the NOM and the filtration age of the membranes is thus shrinked. To tackle these problems, a new type of electrical hollow-fiber microfiltration module (E-HFMF) was designed. In the E-HFMF module, the hollow-fiber microfiltration membranes were placed into the radialized electrical field which functioned from the centre to the exterior of the cylindrical cavity. The main goal of the present study was to evaluate the efficiency of E-HFMF to remove the humic acid (HA, one of the main components of NOM). According to the parallel tests compared with the traditional microfiltration, the removal rate of humic acid was raised to 70%˜85% in terms of UV-254 and to 60%˜75% in terms of DOC when filtrating with the E-HFMF, while the removal rates of humic acid were 10%˜20% and 1%˜10% respectively when filtrating with the traditional microfiltration. The negative charged humic acid moved to the anode because of the electrophoresis, so few humic acid could be able to permeate through the membrane. The electrophoresis mobility of the humic acid permeating through the traditional microfiltration decreased by 19%, while the same index from the E-HFMF decreased by 75%. This indicated that the electrophoresis played a significant role on removing the humic acid. According to the gel permeate chromatograph analysis, humic acid aggregated in an electric field and thus forms loose and permeable cake layer on the membrane surface, which also relieved membrane fouling. Meanwhile, the negative charged humic acid migrating to the anode at the center minimized the deposition onto the membrane surface, and eliminated the membrane fouling as a result. During the E-HFMF filtration, the

  8. Speciation of aquatic Hg{sup 2+} in humic substances by time differential perturbed angular correlation

    Energy Technology Data Exchange (ETDEWEB)

    Franke, K.; Kupsch, H. [Universitat Leipzig, (Germany). Institut fuer Geophysik and Geologie; Troger, W.; Butz, T. [Universitat Leipzig, (Germany). Institut fuer Experimentelle Physik II

    1997-10-01

    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 that the natural heavy metal abundance (i.e. 10{sup -10} molar). This serious limitation can be overcome by the use of suitable radioisotope 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 quadrupole interaction (NQI)of the short-lived radioisotopes {sup 111m}Cd ({tau}{sub l/2} = 49 min) and {sup 199m}Hg ({tau}{sub 1/2} = 43 min) supplied by ISOLDE via {gamma}-{gamma} -TDPAC and compared the {sup 111m}Cd/{sup 199m}Hg-NQIs in humic substances with the known NQI of model compounds (i.e. metal proteins, organometallic compounds). At lowest Hg(II) concentrations (10{sup -10} molar) only linear Hg(ll) coordinations with nitrogen and/or sulfur were observed, with increasing Hg(II) concentration additional distorted trigonal (at 2.5.10{sup -10} molar) and tetrahedral coordinations (at 2.5.10{sup -8} molar) with various ligands show up and start to become dominant at Hg(II) concentrations of 10{sup -7} molar and higher. Contrary to Hg(II), we observed unspecific binding for Cd(lI) in the {sup 111m}Cd-TDPAC experiments only, even in the 10{sup -10} molar concentration range 21 refs., 3 tabs.,3 figs.

  9. Preparation and adsorption behavior for metal ions and humic acid of chitosan derivatives crosslinked by irradiation

    International Nuclear Information System (INIS)

    Zhao Long; Mitomo, H.; Yoshii, F.

    2006-01-01

    Introduction: Removing metal ions and humic acid from water in water treatment has attracted much environment and health interests. Adsorbents, derived from a nature polymer, are desired in the viewpoints of environment-conscious technologies. Recently, some nature materials such as chitin, chitosan and their derivatives have been identified as an attractive option due to their distinctive properties. For an insoluble adsorbent based on these polymers to be obtained over a broad pH range, modification through crosslinking is required. Crosslinking agents such as glutaric dialdehyde and ethylene glycol diglycidyl ether are frequently used for modification. However, these crosslinking agents are not preferred because of their physiological toxicity. Radiation-crosslinking without any additive in the fabrication process results in a high-purity product. In a previous work, we applied ionizing radiation to induce the crosslinking of carboxymethylchitosan under highly concentrated paste-like conditions. The aim of this study is to investigate the adsorption behavior of metal ions, humic acid on irradiation-crosslinked carboxymethylchitosan. Experimental: Irradiation of chitosan samples at paste-like state was done with an electron beam. The solubility test of these crosslinked materials were investigated in acidic, alkaline media, and some organic solvents. Swelling and charged characteristic analyses demonstrated typically pH-sensitive properties of these crosslinked materials. Scanning electron microscopic images showed that the crosslinked samples possessed porous morphological structure. The adsorption studies were carried out by the batch method at room temperature. Adsorption of heavy metal ions (such as Cu 2+ , Cd 2+ ) and humic acid onto crosslinked samples was found to be strongly pH-dependent. Adsorption kinetic studies indicated the rapid removal of metal ions, and humic acid from the aqueous solutions. Also, isothermal adsorption data revealed that Cu 2

  10. Uranium accumulation in Brassica rapa L. and effect of citric acid and humic acids as chelating agents

    International Nuclear Information System (INIS)

    Lopez del R, H.; Perez C, G. A.; Davila R, J. I.; Mireles G, F.; Rodriguez H, G.

    2016-09-01

    Phyto extraction is a technique that makes use of plants for the remediation of soils contaminated with heavy metals. In this study the uranium incorporation in the Brassica rapa L. species was evaluated, in artificially contaminated inert soils with 40 mg U/kg, and the effect of adding of the natural chelating agents citric acid and humic acids in the accumulation of uranium was analyzed. Soil free of organic matter and biologically inert was obtained by controlled calcination s of natural soil. Cultures in the prepared soil consisted of five growth treatments: 1) cultivation without uranium or additives; 2) cultivation in the uranium presence; 3) cultivation with uranium and citric acid (2 g/kg); 4) cultivation with uranium and humic acids (10 g/kg); 5) uranium cultivation and combination of citric and humic acids at the same concentrations. There was no adverse effect on plant growth with the presence of uranium at the given concentration. Regarding the controls, the total biomass in the presence of uranium was slightly higher, while the addition of humic acids significantly stimulated the production of biomass with respect to the citric acid. The combined action of organic acids produced the highest amount of biomass. The efficiency of phyto extraction followed the order Humic acids (301 μg U/g) > Non-assisted (224 μg U/g) >> Citric acid + Humic acids (68 μg U/g) > Citric acid (59 μg U/g). The values of uranium concentration in the total biomass show that the species Brassica rapa L. has the capacity of phyto extraction of uranium in contaminated soils. The addition of humic acids increases the uranium extraction while the addition of citric acid disadvantages it. (Author)

  11. Effect of humic-plant feed preparations on biochemical blood parameters of laying hens in deep litter housing system.

    Science.gov (United States)

    Bubel, F; Dobrzański, Z; Gaweł, A; Pogoda-Sewerniak, K; Grela, E R

    2015-01-01

    An influence of various humic-plant feed additives based on some herbs (nettle, chamomile, yarrow, perforatum), lucerne and humic materials on biochemical indices of Lohmann Brown (LB) layers blood plasma was estimated. Hens were housed in deep litter system, 20 birds in a group. Four groups were formed: control (C - standard feeding), and experimental, supplemented with prepara- tions: E-1 herbal-humic, E-2 humic-herbal and E-3--humic-lucerne. Hens were placed in the pens on the 16th week of life, addition of preparations with standard food mixture started at the 22nd wk and lasted until 66th wk of life. Blood for analyses was collected four times in the following periods: 27, 37, 54 and 65th wk of life. The applied humic-plant preparations to a limited degree affected the values of examined biochemical parameters in serum: total protein (TP), albumins (Albs), glucose (Glu), urea, triacylglycerols (TAG), total cholesterol (TCh), alanine aminotransferase (ALT), aspartate aminot- ransferase (AST) and alkaline phosphatase (ALP). It is difficult to determine based on these study, which preparation is one the most active biologically, however is seems that humic-lucerne prepara- tion affected the examined blood parameters to the highest degree. The reference values ranges in hens blood serum LB hens were proposed for: TP (43-65 g/l), Albs (15-22 g/l), urea (0.5-1.2 mmol/l), Glu 10-15 mmol/l), TCh (2.2-4.5 mmol/l), TAG (10-24 mmol/l), AST (4-12 U/l), ALT (150-280 mmol/l) and ALP (190-350 U/l).

  12. Kinetic behavior of Fe(o,o-EDDHA)-humic substance mixtures in several soil components and in calcareous soils.

    Science.gov (United States)

    Cerdán, Mar; Alcañiz, Sara; Juárez, Margarita; Jordá, Juana D; Bermúdez, Dolores

    2007-10-31

    Ferric ethylenediamine- N, N'-bis-(o-hydroxyphenylacetic)acid chelate (Fe(o, o-EDDHA)) is one of the most effective Fe fertilizers in calcareous soils. However, humic substances are occasionally combined with iron chelates in drip irrigation systems in order to lower costs. The reactivity of iron chelate-humic substance mixtures in several soil components and in calcareous soils was investigated through interaction tests, and their behavior was compared to the application of iron chelates and humic substances separately. Two commercial humic substances and two Fe(o, o-EDDHA) chelates (one synthesized in the laboratory and one commercial) were used to prepare iron chelate-humic substance mixtures at 50% (w/w). Various soil components (calcium carbonate, gibbsite, amorphous iron oxide, hematite, tenorite, zincite, amorphous Mn oxide, and peat) and three calcareous soils were shaken for 15 days with the mixtures and with iron chelate and humic substance solutions. The kinetic behavior of Fe(o, o-EDDHA) and Fe non-(o,o-EDDHA) (Fe bonded to (o,p-EDDHA) and other polycondensated ligands) and of the different nutrients solubilized after the interaction assay was determined. The results showed that the mixtures did not significantly reduce the retention of Fe(o, o-EDDHA) and Fe non-(o,o-EDDHA) in the soil components and the calcareous soils compared to the iron chelate solutions, but they did produce changes in the retention rate. Moreover, the competition between humic substances and synthetic chelating agents for complexing metal cations limited the effectiveness of the mixtures to mobilize nutrients from the substrates. The presence of Fe(o, p-EDDHA) and other byproducts in the commercial iron chelate had an important effect on the evolution of Fe(o, o-EDDHA) and the nutrient solubilization process.

  13. Coagulation of humic substances and dissolved organic matter with a ferric salt: an electron energy loss spectroscopy investigation.

    Science.gov (United States)

    Jung, A-V; Chanudet, V; Ghanbaja, J; Lartiges, B S; Bersillon, J-L

    2005-10-01

    Transmission electron microscopy (TEM) coupled with electron energy loss spectroscopy (EELS) and energy dispersive X-ray spectroscopy (EDXS) was used to investigate the coagulation of natural organic matter with a ferric salt. Jar-test experiments were first conducted with a reconstituted water containing either synthetic or natural extracts of humic substances, and then with a raw water from Moselle River (France). The characterization of the freeze-dried coagulated sediment by EELS in the 250-450 eV range, showed that Fe-coagulant species predominantly associate with the carboxylic groups of organic matter, and that this interaction is accompanied by a release of previously complexed calcium ions. The variation of Fe/C elemental ratio with iron concentration provides insightful information into the coagulation mechanism of humic substances. At acid pH, Fe/C remains close to 3 over the whole range of iron concentrations investigated, while a much lower atomic ratio is expected from the value of optimal coagulant dosage. This suggests that a charge neutralization/complexation mechanism is responsible for the removal of humic colloids, the aggregates being formed with both iron-coagulated and proton-neutralized organic compounds. At pH 8, the decrease in Fe/C around optimal coagulant concentration is interpreted as a bridging of stretched humic macromolecules by Fe-hydrolyzed species. Aggregation would then result from a competition between reconformation of humic chains around coagulant species and collision of destabilized humic material. EELS also enabled a fingerpriting of natural organic substances contained in the iron-coagulated surface water, N/C elemental analyses revealing that humic colloids are removed prior to proteinic compounds.

  14. 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.

  15. Quantification and prediction of the detoxifying properties of humic substances related to their chemical binding to polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Perminova, I V; Grechishcheva, N Y; Kovalevskii, D V; Kudryavtsev, A V; Petrosyan, V S; Matorin, D N

    2001-10-01

    Effects of 27 different humic materials on the toxicity of polycyclic aromatic hydrocarbons (PAH) were studied for crustacean Daphnia magna. Sources included isolated humic acids, fulvic acids, and their combination from soil, peat, and freshwater. The PAH used were pyrene, fluoranthene, and anthracene. The observed reduction in toxicity of PAH in the presence of humic substances (HS) was shown to be a result of the detoxification effect caused by the chemical binding of PAH to HS and of the direct effect of HS on D. magna. An approach was developed to quantify the detoxifying impact of humic materials related to their chemical binding to PAH with a use of the "constant of detoxification" or "toxicological partition coefficient" K(oc)D. The latter was proposed to determine by fitting the experimental relationships of the detoxification effect versus concentration of HS. The obtained K(oc)D values were well tracked by the corresponding partition coefficients determined by the fluorescence quenching technique (K(oc)fq): K(oc)D=b x K(oc)fq, b (mean+/-Cl, n=26, P=95%)=2.6+/-0.3, 4.6+/-0.6, and 6.0+/-1.4 for pyrene, fluoranthene, and anthracene, respectively. The predictive relationships between the structure and detoxifying properties of humic materials in relation to PAH were developed. It was shown that the magnitude of the K(oc)D values correlated closely with the aromaticity of humic materials characterized with the 13C NMR descriptors (sigma(C)Ar, sigma(C)Ar/sigma(C)Alk) and atomic H/C ratio. The obtained relationships showed the highest detoxifying potential of the humic materials enriched with aromatics and allowed a conclusion on the chemical binding as the governing mechanism of the mitigating action of HS on the toxicity of PAH.

  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. Degradation of trinitrotoluene in contaminated soils as affected by its initial concentrations and its binding to soil organic matter fractions.

    Science.gov (United States)

    Singh, Neera; Hennecke, Dieter; Hoerner, Jennifer; Koerdel, Werner; Schaeffer, Andreas

    2008-03-01

    Trinitrotoluene (TNT), a nitroaromatics, is a major pollutant in explosive contaminated soils. Present study reports the effect of initial concentration of TNT on its degradation kinetics in soils. Soils from two contaminated sites viz. Clausthal and Elsnig, Germany, were mixed with an uncontaminated reference soil to get different initial concentrations (mg/kg) viz Clausthal-1 (54.29), Clausthal-2 (30.86), Clausthal-3 (7.05) Elsnig-1 (879.67), Elsnig-2 (86.43); Elsnig-3 (8.16) and Elsnig-4 (0.99) and were spiked with ring UL-(14)C-TNT (100KBq/50g soil). Except Elsnig-1 and Elsnig-2 soils, TNT degraded at same rate in all the soils. Higher persistence of TNT in Elsnig-1 and Elsnig-2 soils appears to be due to higher initial concentrations of nitroaromatics which may be toxic to soil microorganisms. 2-Amino-4,6-dinitrotoluene (2-ADNT) and 4-amino-2,6-dinitrotoluene (4-ADNT) were recovered as major metabolites of TNT. Distribution of bound (14)C-activity in different soil organic matter (SOM) fractions (humic acid, fulvic acid and humin) was assayed by alkali extraction of solvent extracted Clausthal-1 and Elsnig-1 soils. Results indicate that humic acid accounted for maximum bound activity followed by fulvic acid and humin fractions. Expressing (14)C-activity bound/unit weight of organic carbon content of SOM fractions showed that 3 times more (14)C-activity was bound to Elsnig humic acid than Clausthal humic acid. Similarly, activity associated with Elsnig fulvic acid was 7 times higher than that of Clausthal fulvic acid suggesting that chemical nature of SOM fractions plays a significant role in binding of contaminants.

  18. PEM fuel cell degradation

    Energy Technology Data Exchange (ETDEWEB)

    Borup, Rodney L [Los Alamos National Laboratory; Mukundan, Rangachary [Los Alamos National Laboratory

    2010-01-01

    The durability of PEM fuel cells is a major barrier to the commercialization of these systems for stationary and transportation power applications. While significant progress has been made in understanding degradation mechanisms and improving materials, further improvements in durability are required to meet commercialization targets. Catalyst and electrode durability remains a primary degradation mode, with much work reported on understanding how the catalyst and electrode structure degrades. Accelerated Stress Tests (ASTs) are used to rapidly evaluate component degradation, however the results are sometimes easy, and other times difficult to correlate. Tests that were developed to accelerate degradation of single components are shown to also affect other component's degradation modes. Non-ideal examples of this include ASTs examining catalyst degradation performances losses due to catalyst degradation do not always well correlate with catalyst surface area and also lead to losses in mass transport.

  19. 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

  20. Immobilized humic substances as redox mediator for the simultaneous removal of phenol and Reactive Red 2 in a UASB reactor.

    Science.gov (United States)

    Martínez, Claudia M; Celis, Lourdes B; Cervantes, Francisco J

    2013-11-01

    The present study reports a novel treatment concept combining the redox-mediating capacity of immobilized humic substances with the biodegrading activity of anaerobic sludge for the simultaneous removal of two representative pollutants of textile wastewaters (e.g., phenol and Reactive Red 2 (RR2)) in a high-rate anaerobic reactor. The use of immobilized humic substances (1 g total organic carbon (TOC) L(-1), supported on an anion exchange resin) in an upflow anaerobic sludge blanket (UASB) reactor increased the decolorization efficiency of RR2 (~90 %), extent of phenol oxidation (~75 %), and stability as compared to a control UASB reactor operated without immobilized humic substances, which collapsed after 120 days of dye introduction (50-100 mg L(-1)). Increase in the concentration of immobilized humic substances (2 g TOC L(-1)) further enhanced the stability and efficiency of the UASB reactor. Detection of aniline in the effluent as RR2 reduction product confirmed that reduction of RR2 was the major mechanism of dye removal. This is the first demonstration of immobilized humic substances serving as effective redox mediators for the removal of recalcitrant pollutants from wastewater in a high-rate anaerobic bioreactor. The novel treatment concept could also be applicable to remove a wide variety of contaminants susceptible to redox conversion, which are commonly found in different industrial sectors.

  1. Effect of Humic Acid and Phosphorus on the Quantity and Quality of Marigold (Calendula officinalis L. Yield

    Directory of Open Access Journals (Sweden)

    A.A Farjami,

    2014-03-01

    Full Text Available To evaluate the effect of humic acid and phosphorus on the quantity and quality of marigold yield an experiment was conducted at Research Field of Islamic Azad University, Mashhad Branch, Mashhad, Iran, in cropping season 2010-2011. The experiment was in split plot based on randomized complete block design, with four replications. The main plots were humic acid in four levels (0, 5, 10 and 15 kg/ha and sub plots were phosphorus (P2O5 in three levels (40, 60 and 80 kg/ha. The result showed that the highest dry flower yield (158.4 g/m2, flower number (1356 per m2, essential oil (0.55%, active ingredient of flower (0.31%, obtained in humic acid (10 kg/ha and phosphorus (60kg/ha. The results also revalued that highest grain yield (133.8 g/m2 and seed oil (0.41% obtained when (5 kg/ha humic acid and 80kg/ha phosphorus were used. Based on this study, humic acid (10 kg/ha and phosphorus (60kg/ha may result in higher yield.

  2. Effects of humic acids from landfill leachate on plants: An integrated approach using chemical, biochemical and cytogenetic analysis.

    Science.gov (United States)

    Morozesk, Mariana; Bonomo, Marina Marques; Souza, Iara da Costa; Rocha, Lívia Dorsch; Duarte, Ian Drumond; Martins, Ian Oliveira; Dobbss, Leonardo Barros; Carneiro, Maria Tereza Weitzel Dias; Fernandes, Marisa Narciso; Matsumoto, Silvia Tamie

    2017-10-01

    Biological process treatment of landfill leachate produces a significant amount of sludge, characterized by high levels of organic matter from which humic acids are known to activate several enzymes of energy metabolism, stimulating plant growth. This study aimed to characterize humic acids extracted from landfill sludge and assess the effects on plants exposed to different concentrations (0.5, 1, 2 and 4 mM C L -1 ) by chemical and biological analysis, to elucidate the influence of such organic material and minimize potential risks of using sludge in natura. Landfill humic acids showed high carbon and nitrogen levels, which may represent an important source of nutrients for plants. Biochemical analysis demonstrated an increase of enzyme activity, especially H + -ATPase in 2 mM C L -1 landfill humic acid. Additionally, cytogenetic alterations were observed in meristematic and F 1 cells, through nuclear abnormalities and micronuclei. Multivariate statistical analysis provided integration of physical, chemical and biological data. Despite all the nutritional benefits of humic acids and their activation of plant antioxidant systems, the observed biological effects showed concerning levels of mutagenicity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. 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.

  4. Evaluation of Mycorrhizal Fungi, Vermicompost and Humic Acid on Essence Yield and Root Colonization of Fennel

    Directory of Open Access Journals (Sweden)

    I. Akbari

    2016-02-01

    Full Text Available Introduction The main objective of sustainable agriculture is to decrease the off-farm inputs such as chemical fertilizers, increased farm nutrient cycle through reduced tillage and the use of biological and organic fertilizers. Studies on medicinal plants indicates that the use of sustainable farming systems provide the best conditions for the production of these plants. Mycorrhizal fungi, vermicompost and humic acid are samples of biological and organic fertilizer that can be used, to eliminate or substantially reduce the use of chemical inputs in order to increase the quantity, quality and stability of the products. Mycorrhizal fungi are one of the most important rhizosphere microorganisms which have symbiotic relation with root of most crops. Mycorrhizal symbiosis improves the soil physical (through expansion of hyphae of fungus, chemical (through increased absorption of nutrients and biological (the soil food web quality. These fungus increased nutrient uptake, such as phosphorus and some micronutrients, water uptake, reducing the negative effects of environmental stress and increase resistance to pathogens and improve the quality of their host plants. Fennel (Foeniculum vulgare Mill is one of the most important medicinal plants, as the essential oil from the seeds used in a variety of industries, pharmaceutical, food and cosmetic use. Anethole is important component of the essential oil of fennel seed. Materials and Methods This experiment was conducted as a factorial based on randomized complete block design in order to evaluate the effects of vermicompost application, humic acid and mycorrhizal fungi on quantitative and qualitative aspects of fennel yield at experimental farm of Shahrood University during growing season of 1391-92. This experiment includes 12 treatments and 3 applications. Vermicompost levels include: v1 (no application v2 (4 ton ha-1 v3 (8 ton ha-1. Mycorrhizal fungi include: m1 (no inoculation and m2 (inoculation and

  5. The humic matter as natural inhibitor of CaCO{sub 3} in cooling water system; Las sustancias humicas como inhibidores naturales del CaCO{sub 3}, en sistemas de enfriamiento

    Energy Technology Data Exchange (ETDEWEB)

    Celada Murillo, Ana Teresa [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    2000-07-01

    Important problems are presented in cooling water systems by the formation of mineral deposits on the heat transference equipment. Calcium carbonate (CaCO{sub 3}) is one of the minerals that more deposits produces. The CaCO{sub 3} scale is controlled by the addition of sulfuric acid and chemical inhibitors with phosphates (among the most utilized). These chemicals bring an environmental impact because they are associate with eutrophication of water bodies. In order to contribute to the decrease of the use of these chemical additives, this investigation proposes the utilization of humic matter as natural inhibitor of CaCO{sub 3}, precipitation. Humic matter is a complex organic molecule present in water-and soils by the degradation of plants and animals dead. Humic matter participates in ionic interchange complex and adsorption reactions with metallic ions. Inhibition of CaCO{sub 3} precipitation was observed in synthetic and naturals water solutions (well water, river water and treated wastewater). These solutions contained typical concentrations of calcium and alkalinity of makeup and circulation water of cooling systems in electrical power plants in Mexico. The CaCO{sub 3} precipitation in these solutions was induced by the addition of NaOH 0.1 N in continuos form (pH critical method), in absence and presence of humic matter. Time and NaOH volume were registered. Increase of CaCO{sub 3} nucleation time was evident in presence of humic matter. In the synthetic solutions, the nucleation time was increased 30-40%; while in the natural watery solutions (well water) the humic inhibited the CaCO{sub 3} precipitation during 120 minutes of experimentation. [Spanish] En la instalacion de sistemas solares para enfriamiento que emplean agua se presentan problemas importantes por la formacion de depositos minerales sobre equipos de transferencia de calor. El carbonato de calcio (CaCO{sub 3}) es uno de los minerales que mas depositos produce. Con el fin de disminuir su

  6. Effects of soil organic matter on the development of the microbial polycyclic aromatic hydrocarbons (PAHs) degradation potentials.

    Science.gov (United States)

    Yang, Y; Zhang, N; Xue, M; Lu, S T; Tao, S

    2011-02-01

    The microbial activity in soils was a critical factor governing the degradation of organic micro-pollutants. The present study was conducted to analyze the effects of soil organic matter on the development of degradation potentials for polycyclic aromatic hydrocarbons (PAHs). Most of the degradation kinetics for PAHs by the indigenous microorganisms developed in soils can be fitted with the Logistic growth models. The microbial activities were relatively lower in the soils with the lowest and highest organic matter content, which were likely due to the nutrition limit and PAH sequestration. The microbial activities developed in humic acid (HA) were much higher than those developed in humin, which was demonstrated to be able to sequester organic pollutants stronger. The results suggested that the nutrition support and sequestration were the two major mechanisms, that soil organic matter influenced the development of microbial PAHs degradation potentials. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. Targeting proteins for degradation.

    Science.gov (United States)

    Schrader, Erin K; Harstad, Kristine G; Matouschek, Andreas

    2009-11-01

    Protein degradation plays a central role in many cellular functions. Misfolded and damaged proteins are removed from the cell to avoid toxicity. The concentrations of regulatory proteins are adjusted by degradation at the appropriate time. Both foreign and native proteins are digested into small peptides as part of the adaptive immune response. In eukaryotic cells, an ATP-dependent protease called the proteasome is responsible for much of this proteolysis. Proteins are targeted for proteasomal degradation by a two-part degron, which consists of a proteasome binding signal and a degradation initiation site. Here we describe how both components contribute to the specificity of degradation.

  8. 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

  9. 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.

  10. Effect of humic acid on water chemistry, bioavailability and toxicity of aluminium in the freshwater snail, Lymnaea stagnalis, at neutral pH

    Energy Technology Data Exchange (ETDEWEB)

    Dobranskyte, A. [Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester M13 9PT (United Kingdom); Jugdaohsingh, R. [Gastrointestinal Laboratory, Rayne Institute, St Thomas' Hospital, London SE1 7EH (United Kingdom); McCrohan, C.R. [Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester M13 9PT (United Kingdom); Stuchlik, E. [Hydrobiological Station, Institute for Environmental Studies, Charles University, Prague (Czech Republic); Powell, J.J. [MRC Human Nutrition Research, Elsie Widdowson Laboratory, Fulbourn Road, Cambridge CB1 9NL (United Kingdom); White, K.N. [Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester M13 9PT (United Kingdom)]. E-mail: keith.white@manchester.ac.uk

    2006-03-15

    The influence of humic acid on the water chemistry of environmentally relevant concentrations of Al at neutral pH was studied, together with its effect on the bioavailability and toxicity of Al in Lymnaea stagnalis. Humic acid significantly reduced the loss of Al from the water and increased the fraction of filterable Al, although this was a relatively small fraction of total Al. Filterable Al concentration in the presence or absence of humic acid was independent of initial Al concentration. Humic acid only partly reduced toxicity, as observed by a reduction in behavioural suppression, and had no effect on the level of Al accumulated in tissues. These results suggest that humic acid maintains Al in a colloidal form that is bioavailable to L. stagnalis. However, these colloidal Al-humic acid species were less toxic since behavioural toxicity was reduced. Humic acid may play an important role in limiting the toxicity of Al to freshwater organisms. - Humic acid reduces aluminium toxicity in freshwater snails.

  11. Molecular chemistry in humic Ferralsols from Brazilian Cerrado and forest biomes indicates a major contribution from black carbon in the subsoil

    NARCIS (Netherlands)

    Marques, F.A.; Buurman, P.; Schellekens, J.; Vidal-Torrado, P.

    2015-01-01

    Soil organic matter (OM) stability plays an important role in the global carbon cycle. The molecular characterisation of soil OM may contribute to an understanding of the feedback mechanisms between soil OM and climate. Umbric Ferralsols with humic properties (humic Ferralsols) are characterised by

  12. 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

  13. Humic substances and its distribution in coffee crop under cover crops and weed control methods

    Directory of Open Access Journals (Sweden)

    Bruno Henrique Martins

    2016-08-01

    Full Text Available ABSTRACT Humic substances (HS comprise the passive element in soil organic matter (SOM, and represent one of the soil carbon pools which may be altered by different cover crops and weed control methods. This study aimed to assess HS distribution and characteristics in an experimental coffee crop area subjected to cover crops and cultural, mechanical, and chemical weed control. The study was carried out at Londrina, in the state of Paraná, southern Brazil (23°21’30” S; 51°10’17” W. In 2008, seven weed control/cover crops were established in a randomized block design between two coffee rows as the main-plot factor per plot and soil sampling depths (0-10 cm, 10-20 cm, 20-30 cm and 30-40 cm as a split-plot. HS were extracted through alkaline and acid solutions and analyzed by chromic acid wet oxidation and UV-Vis spectroscopy. Chemical attributes presented variations in the topsoil between the field conditions analyzed. Cover crop cutting and coffee tree pruning residues left on the soil surface may have interfered in nutrient cycling and the humification process. Data showed that humic substances comprised about 50 % of SOM. Although different cover crops and weed control methods did not alter humic and fulvic acid carbon content, a possible incidence of condensed aromatic structures at depth increments in fulvic acids was observed, leading to an average decrease of 53 % in the E4/E6 ratio. Humin carbon content increased 25 % in the topsoil, particularly under crop weed-control methods, probably due to high incorporation of recalcitrant structures from coffee tree pruning residues and cover crops.

  14. Hygroscopic growth of common organic aerosol solutes, including humic substances, as derived from water activity measurements

    Science.gov (United States)

    Zamora, Idania R.; Tabazadeh, Azadeh; Golden, David M.; Jacobson, Mark Z.

    2011-12-01

    Studies have shown that organic matter often constitutes up to 50% by mass of tropospheric aerosols. These organics may considerably affect the water uptake properties of these aerosols, impacting Earth's climate and atmosphere. However, considerable uncertainties still exist about hygroscopic properties of organic carbon (OC) in particles. In this study, we have assembled an apparatus to measure equilibrium water vapor pressure over bulk solutions. We used these results to calculate the hygroscopic growth curve and deliquescence relative humidity (DRH) of representative compounds in three OC categories: saccharides, mono/dicarboxylic acids, and HULIS (Humic-Like Substances). To our knowledge, this is the first study to examine the hygroscopic growth of HULIS by means of a bulk method on representative compounds such as fulvic and humic acids. We also explored the temperature effect on hygroscopic growth within the 0°C-30°C temperature range and found no effect. The DRH and hygroscopic growth obtained were in excellent agreement with published tandem differential mobility analyzer (TDMA), electrodynamic balance, and bulk data for sodium chloride, ammonium sulfate, d-glucose, levoglucosan, succinic acid, and glutaric acid. However, we found a hygroscopic growth factor of 1.0 at a relative humidity of 90% for phthalic, oxalic, humic, and two fulvic acids; these results disagree with various TDMA studies. The TDMA is used widely to study water uptake of organic particles but can be affected by particle microstructural arrangements before the DRH and by the inability to fully dry particles. Thus, in the future it will be important to confirm TDMA data for nondeliquescent organic particles with alternate methods.

  15. 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.

  16. The effect of the humic acid and herbal additive supplement on production parameters of broiler chicken

    Directory of Open Access Journals (Sweden)

    Veronika Pistová

    2016-10-01

    Full Text Available In this study the effect of humic acids and dietary herbal additive (clove (Syzygium aromaticum, lavender (Lavendula angustifolia and black pepper (Piper nigrum L. on production parameters of broiler chicken were studied.  A total of 60 Ross 308 broiler chicken were divided into 3 treatments (n=20. The control group of chickens was fed with complete feed mixtures without any additives. Chicken in treatment T1 were fed a diet containing 1% of humic acid and drank a water containing 150 mg/l of herbal additive. Chicken in treatment T2 were fed with complete feed mixture without any additives and drank a water containing 150 mg/l of herbal additive. The body weight, feed intake and feed conversion were evaluated. The results shout that the body weight was significantly higher (P≤0.05 in treatments groups compared to the control group (the order of the groups: 1796.4±188.1; 2052.9±197.9 and 2140.4±300.4 g±SD. The feed intake was in the control group 3.11 kg, in the treatment T1 3.00 kg and in the treatment T2 3.12 kg. Feed conversion for the entire fattening period was in control group 2.19 kg/kg complete feed mixture, in the treatment T1 1.83 kg/kg complete feed mixture and in the treatment T2 1.84 kg/kg complete feed mixture with no significant different (P≥0.05 compared to control group. In conclusion, supplement by humic acid and herbal additive can improve production parameters of broiler chicken.

  17. An innovative zinc oxide-coated zeolite adsorbent for removal of humic acid

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lingling, E-mail: lasier_wang@hotmail.com [College of Chemical Engineering and Materials, Quanzhou Normal University, Quanzhou 362000, Fujian (China); Environmental Engineering and Science Program, 705 Engineering Research Center, University of Cincinnati, Cincinnati, OH 45221-0012 (United States); Han, Changseok [ORISE Post-doctoral Fellow, The U.S. Environmental Protection Agency, ORD, NRMRL, STD, CPB, 26 W. Martin Luther King Jr. Drive, Cincinnati, OH 45268 (United States); Nadagouda, Mallikarjuna N. [The U.S. Environmental Protection Agency, ORD, NRMRL, WSWRD, WQMB, 26 W. Martin Luther King Jr. Drive, Cincinnati, OH 45268 (United States); Dionysiou, Dionysios D., E-mail: dionysios.d.dionysiou@uc.edu [Environmental Engineering and Science Program, 705 Engineering Research Center, University of Cincinnati, Cincinnati, OH 45221-0012 (United States); Nireas-International Water Research Centre, School of Engineering, University of Cyprus, PO Box 20537, 1678, Nicosia (Cyprus)

    2016-08-05

    Highlights: • An innovative adsorbent was successfully synthesized to remove humic acid. • The adsorbent possessed high adsorption capacity for humic acid. • The adsorption capacity remarkably increased after an acid modification. • The adsorption capacity was proportional to the amount of ZnO coated on zeolite. • Electrostatic interactions are a major factor at the first stage of the process. - Abstract: Zinc oxide (ZnO)-coated zeolite adsorbents were developed by both nitric acid modification and Zn(NO{sub 3}){sub 2}·6H{sub 2}O functionalization of zeolite 4A. The developed adsorbents were used for the removal of humic acid (HA) from aqueous solutions. The synthesized materials were characterized by porosimetry analysis, scanning electron microscopy, X-Ray diffraction analysis, and high resolution transmission electron microscopy. The maximum adsorption capacity of the adsorbents at 21 ± 1 °C was about 60 mgC g{sup −1}. The results showed that the positive charge density of ZnO-coated zeolite adsorbents was proportional to the amount of ZnO coated on zeolite and thus, ZnO-coated zeolite adsorbents exhibited a greater affinity for negatively charged ions. Furthermore, the adsorption capacity of ZnO-coated zeolite adsorbents increased markedly after acid modification. Adsorption experiments demonstrated ZnO-coated zeolite adsorbents possessed high adsorption capacity to remove HA from aqueous solutions mainly due to strong electrostatic interactions between negative functional groups of HA and the positive charges of ZnO-coated zeolite adsorbents.

  18. The effect of humic acid on uranyl sorption onto bentonite at trace uranium levels.

    Science.gov (United States)

    Ivanov, Peter; Griffiths, Tamara; Bryan, Nick D; Bozhikov, Gospodin; Dmitriev, Serguei

    2012-11-01

    The effect of humic acid (HA) on U(VI) sorption on bentonite was studied in batch experiments at room temperature and ambient atmosphere at a (237)U(VI) concentration of 8.4 × 10(-11) M and HA concentration of 100 mg L(-1). The distribution of U(VI) between the liquid and solid phases was studied as a function of pH and ionic strength both in the absence and presence of HA. It was shown that the uranyl sorption on bentonite is strongly dependent on pH and the presence of humics, and the effect of the addition order was negligible. In the absence of HA an enhancement in the uptake with increasing pH was observed and a sharp sorption edge was found to take place between pH 3.2 and 4.2. The presence of HA slightly increases uranium(VI) sorption at low pH and curtails it at moderate pH, compared to the absence of HA. In the basic pH range for both the presence and absence of HA the sorption of uranium is significantly reduced, which could be attributed to the formation of soluble uranyl carbonate complexes. The influence of ionic strength on U(VI) and HA uptake by bentonite were investigated in the range of 0.01-1.0 M, and while there was an enhancement in the sorption of humic acid with increasing ionic strength, no significant effect of the ionic strength on the U(VI) sorption was observed in both the absence and presence of HA.

  19. Carbon in Humic Fractions of Organic Matter in Soil Treated with Organic Composts under Mango Cultivation

    Directory of Open Access Journals (Sweden)

    Joyce Reis Silva

    2016-01-01

    Full Text Available ABSTRACT Soil organic matter (SOM plays a key role in maintaining the productivity of tropical soils, providing energy and substrate for the biological activity and modifying the physical and chemical characteristics that ensure the maintenance of soil quality and the sustainability of ecosystems. This study assessed the medium-term effect (six years of the application of five organic composts, produced by combining different agro-industrial residues, on accumulation and chemical characteristics of soil organic matter. Treatments were applied in a long-term experiment of organic management of mango (OMM initiated in 2005 with a randomized block design with four replications. Two external areas, one with conventional mango cultivation (CMM and the other a fragment of regenerating Caatinga vegetation (RCF, were used as reference areas. Soil samples were collected in the three management systems from the 0.00-0.05, 0.05-0.10, and 0.10-0.20 m layers, and the total organic carbon content and chemical fractions of organic matter were evaluated by determining the C contents of humin and humic and fulvic acids. Organic compost application significantly increased the contents of total C and C in humic substances in the experimental plots, mainly in the surface layer. However, compost 3 (50 % coconut bagasse, 40 % goat manure, 10 % castor bean residues significantly increased the level of the non-humic fraction, probably due to the higher contents of recalcitrant material in the initial composition. The highest increases from application of the composts were in the humin, followed by the fulvic fraction. Compost application increased the proportion of higher molecular weight components, indicating higher stability of the organic matter.

  20. 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

  1. 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...... shifts of all substructures from the proposed models. A full reconstruction makes sure that all carbons are accounted for and enables on the negative side to discuss structural elements identified from recorded spectra of humic substances that cannot be observed in the simulated spectrum. On the positive...... side missing structural elements in the models can be suggested. A number of proposed structures for humic and fulvic acids are discussed based on the above analysis....

  2. The thermodynamic stability of hydrogen bonded and cation bridged complexes of humic acid models-A theoretical study

    International Nuclear Information System (INIS)

    Aquino, Adelia J.A.; Tunega, Daniel; Pasalic, Hasan; Haberhauer, Georg; Gerzabek, Martin H.; Lischka, Hans

    2008-01-01

    Hydrogen bonded and cation bridged complexation of poly(acrylic acid) oligomers, representing a model compound for humic acids, with acetic acid and the herbicide (4-chloro-2-methylphenoxy) acetic acid (MCPA) have been studied by means of density functional theory. Solvation effects were computed by means of a combination of microsolvation (explicit insertion of water molecules) and global solvation (polarizable continuum approach). The stability of hydrogen bonded complexes in solution is characterized by a strong competition between solute and solvent molecules. The cation bridged complexes of the negatively charged (deprotonated) ligands were found to be strongly favored explaining the capability of humic acids to fixate anionic species from soil solutions and the ability to form cross-linking structures within the humic acid macromolecules

  3. Effect of Humic Acid and Organic Manure Tea on Plant Physiology and Fruit Characteristics of Pepino

    Directory of Open Access Journals (Sweden)

    Jamal Javanmardi

    2017-02-01

    Full Text Available Introduction Pepino (SolanummuricatumAit., a Solanaceous vegetable fruit has been recently introduced to Iran markets. Organic farming is currently the fastest growing agricultural sector worldwide. Although several investigations are available on chemical fertilization of pepino, the knowledge of organic fertilization ismostly lacking. Therefore, at the beginning of introducing pepino plant to Iranian farmers it worth to evaluate the impact of organic fertilization on the productivity, profitability, acceptability and sustainability of farming systemsto this plant. High chemical fertilization of pepinoincreases the vegetative growth over the generative and fruit production. The aim of this investigation was to introduce the possibility of organic production of pepino. Materials and Methods.A two-year experiment was carried out to assess the possibility of organic production of pepino using organic fertilizers. Humistar® organic fertilizer (containing 8.6% humic acid at 50 L/ha and sheep or cow manure teas at 1:10 and 1:5 ratios were used for production of pepino cv. Kanseola to evaluate their effects on the physiology of reproductive stage and some fruit quality characteristics. The experiments were arranged as factorial in a randomized complete block design comprised of 3 replications, each of which 10 plants. Mother plants were obtained from Mashhad Ferdowsi University and incubated in a greenhouse (mean temperature of 25 °C and 60-70% relative humidity for 1 month to proliferate. Cuttings with 2-3 leaves at the top, 3-5 healthy buds and 20 cm length were rooted for 14 days in a rooting media, ( 1:1:2 of field soil, composted leaf and perlite, respectively. Plants were transplanted into the field in 100 × 75 cm spacing after the danger of frost was over. Treatments consisted of two levels of 1:5 and 1:10 (w:w cow or sheep manure teas in combination with two levels of Humistar® organic fertilizer as 0 and 50L/ha levels. Control plants

  4. Mobilization of arsenic and heavy metals from polluted soils by humic acid

    Science.gov (United States)

    Reyes, Arturo; Fuentes, Bárbara; Letelier, María Victoria; Cuevas, Jacqueline

    2017-04-01

    The existence of soils contaminated with harmful elements by mining activities is a global environmental concern. The northern part of Chile has several heavy metal contaminated sites due to former copper and gold artisanal mining activities. Therefore, a complete characterization of abandoned sites and the implementation of remediation technologies are of interest for regulators, the industry, and the population. The objective of the study was to test the use of humic acid as a washing treatment to reduce the heavy metal concentration of soil samples impacted by mine waste material. A stratified random sampling was conducted on the target site to determine the physical and chemical composition of mine waste and soil material. The sampling consisted of taking 37 samples at 0-20 cm depths in a 10,000 square-meter area. The samples were dried and sieved at 2 mm. The batch washing experiments were conducted in triplicate at pH 7.0. A 1:10 solid to liquid ratio and three humic acid dose (0, 50, and 100 mg/l) were used. After shaking (24 h, room temperature) and subsequently filtration (0.22 μm), the supernatants were analyzed for heavy metals, redox potential and pH. The heavy metals mobility was assessed using extraction methods before and after treatments. The soils had alkaline pH values, conductivity ranged between 8 and 35 mS/cm, with low organic matter. Total concentrations of Vanadium (V) (10.80 to 175.00 mg/kg), Lead (Pb) (7.31 to 90.10 mg/kg), Antimonium (Sb) (0.83 to 101.00 mg/kg), and Arsenic (As) (9.53 to 2691.00 mg/kg) exceeded several times the EPA`s recommended values for soils. At 100 mg/L HA the removal efficiencies for V, Pb, Sb, and As were 32, 68, 77, and 82% respectively. According to the extraction procedure V, Pb, Sb, and As species are mainly as oxidizable and residual fractions. According to the results, the target mine site is contaminated with harmful elements. It can be concluded that the use of humic acid is a good alternative as a

  5. 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.

  6. Characterization of commercial humic acid samples and their impact on growth of fungi and plants

    Directory of Open Access Journals (Sweden)

    Asma Lodhi, Shermeen Tahir, Zafar Iqbal, Ansar Mahmood, Muhammad Akhtar, Tariq Mahmood Qureshi, Muhammad Yaqub and Asif Naeem

    2013-05-01

    Full Text Available Naturally occurring humates like leonardite and brown coal or lignite are marketed under different brand names e.g. Pak Humates, Humate Fertilizer, Pak Humax, Humkara and Humide etc. However, their efficacy is needed to be confirmed before their use. Different studies were conducted for the comparison of four commercial humates for their physico-chemical, optical properties, plant growth promoting ability in terms of seed germination and seedling vigour in wheat (cv Sehr, mung bean (Mung-54, maize (C-12 and sesbania and their effect on growth of some fungi. Moisture content of four humates varied from 0.52 to 71.11%, while solubility in water varied from 30.2 to 98.2% and density differed from 1.67 to 4.17. A 2% solution of humates had pH and EC varying from 5.39 to 10.11 and 3.140 to 1.143 mS cm-1, respectively. Carbon and nitrogen concentrations varied from 22.95 to 36.56% and 0.658 to 1.183, respectively with a C/N ratio of 30.91 to 44.16. Humates dissolved in 0.1N NaOH were partitioned into humic acid and fulvic acid fractions. Of the total C in humates, 40.3 to 77.5% was ranged in humic acid and 22.5 to 59.7% in fulvic acid fraction. The HA was also studied for optical properties at 400, 500, 600, and 700 nm besides that at 465 and 665 to calculate E4/E6 (extinction coefficient; the later varied between 3.64 and 5.48. Optical density of the humic acid decreased at increasing wavelength and was correlated significantly with the carbon contents of humic compounds. Three fungi, Trichoderma harzianum, T. hamatum and Alternaria alternata showed maximum growth at 0.025% HA in the growth medium on the basis of colony diameter. Humates inhibited seed germination in wheat, maize and mung bean except for sesbania. Root length and shoot dry matter increased in wheat and maize but no effect was found in mung bean and sesbania. The studies revealed that humates available in the market vary widely and therefore some sort of quality monitoring is required

  7. Nano-MnO2-mediated transformation of triclosan with humic molecules present: kinetics, products, and pathways.

    Science.gov (United States)

    Sun, Kai; Li, Shunyao; Waigi, Michael Gatheru; Huang, Qingguo

    2018-03-10

    It has been shown that manganese dioxide (MnO 2 ) can mediate transformation of phenolic contaminants to form phenoxyl radical intermediates, and subsequently, these intermediates intercouple to form oligomers via covalent binding. However, the reaction kinetics and transformation mechanisms of phenolic contaminants with humic molecules present in nano-MnO 2 -mediated systems were still unclear. In this study, it was proven that nano-MnO 2 were effective in transforming triclosan under acidic conditions (pH 3.5-5.0) during manganese reduction, and the apparent pseudo first-order kinetics rate constants (k = 0.0599-1.5314 h -1 ) increased as the pH decreased. In particular, the transformation of triclosan by nano-MnO 2 was enhanced in the presence of low-concentration humic acid (1-10 mg L -1 ). The variation in the absorption of humic molecules at 275 nm supported possible covalent binding between humic molecules and triclosan in the nano-MnO 2 -mediated systems. A total of four main intermediate products were identified by high-resolution mass spectrometry (HRMS), regardless of humic molecules present in the systems or not. These products correspond to a suite of radical intercoupling reactions (dimers and trimers), ether cleavage (2,4-dichlorophenol), and oxidation to quinone-like products, triggered by electron transfer from triclosan molecules to nano-MnO 2 . A possible reaction pathway in humic acid solutions, including homo-coupling, decomposition, oxidation, and cross-coupling, was proposed. Our findings provide valuable information regarding the environmental fate and transformation mechanism of triclosan by nano-MnO 2 in complex water matrices.

  8. Criterious preparation and characterization of earthworm-composts in view of animal waste recycling. Part I. Correlation between chemical, thermal and FTIR spectroscopic analyses of four humic acids from earthworm-composted animal manure

    Directory of Open Access Journals (Sweden)

    Mangrich Antonio S.

    2000-01-01

    Full Text Available Humic acids (HA were extracted from sheep (SH, cow (CO, goat (GO and rabbit (RA manures which were vermicomposted with the earthworm Eisenia foetida. HA DSC curves showed well-defined thermal events indicative of intramolecular bonds (300 ºC and intermolecular organo-mineral linkages (500 ºC. All samples showed high nitrogen contents (from peptide chains and probably N-heterocycles and aromatic and/or unsaturated aliphatic conjugated structures, as well as a low carboxylic functionality content. The SH-HA was the most similar to a medium soil HA and the RA-HA being the least similar. The results show that it is possible to prepare distinct worm-composts to solve specific problems of degraded soils.

  9. Selectivity and efficiency of three extracting agents in the extraction of humic substances in amazonic soils, Colombia

    International Nuclear Information System (INIS)

    Barragan, C; Uribe, M; Correa, A; Castrillon W

    2001-01-01

    The study of the soil humic substances requires its separation from the mineral fraction. To accomplish this diverse methods and procedures based specially on the extractant efficiency have been used. Different results have been obtained according to the method used. In order to know the efficiency and selectivity of extraction of the humic substances, successive extractions with sodium tetraborate, sodium pyrophosphate and sodium hydroxide, in comparison to the sodium hydroxide used as only extractant were carried out. The study was performed in the Oa horizons of two argillaceous soils: typical paleudults and typical Dystrudepts and in the Oi, Oe, Oa and Ch horizons of a sandy soil classified as typical quartzipsamments, all located in the Lomerio in the Amazon Department, Colombia. The results indicated greater rate of carbon extraction and greater selectivity by means of the successive extractions than the obtained with the sodium hydroxideas only extractant. The highest rate of total extraction was obtained in sandy soils T. Quartzipsamments. The E4/E6 ratios values of the obtained extracts, allowed to state minor degree of condensation of humic acids of the typical quartzipsamments than those of argillaceous: T Dystrudepts, Typic Paleudults and Ch horizons T. Quartzipsamments. The highest value of total acidity was found in the Typical Quartzipsamments using NaOH in successive extractions after sodium tetraborate and sodium pyrophosphate; this amount was minor when this extractant was used alone. There were greater differences of total acidity obtained humic substances by means of the successive extraction, in relation to the obtained one with NaOH like only extractant, but was not seen definite tendency the selective extractions with the acidity. Among the humic substances obtained by means of successive extraction there were greater differences of total acidity values than among the humic substances obtained using NaOH as only extractant. However a defined

  10. Kinetics of the oxidative hydroxylation of tetraphosphorus in the presence of copper(II) chloride modified by humic (fulvo-) acid

    OpenAIRE

    Zhaksyntay Kairbekov; Dina Akbayeva; Zh. Eshova

    2012-01-01

    It was established that in mild conditions (50-70 oC, РО2= 1 atm) white phosphorus effectively is oxidized by oxygen in water-toluene solutions of copper(II) chloride modified by humic (fulvo-) acid to give mainly phosphoric acid. Humic (fulvo-) acid was extracted from brown coal of domestic deposit Kiyakty. For determination of optimum parameters of fulvo-acid extraction the laboratory experiments were carried out using the method of experiment planning. The kinetics, intermediate and final ...

  11. Effects of soil organic matter on the development of the microbial polycyclic aromatic hydrocarbons (PAHs) degradation potentials

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Y.; Zhang, N.; Xue, M.; Lu, S.T. [Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871 (China); Tao, S., E-mail: taos@urban.pku.edu.c [Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871 (China)

    2011-02-15

    The microbial activity in soils was a critical factor governing the degradation of organic micro-pollutants. The present study was conducted to analyze the effects of soil organic matter on the development of degradation potentials for polycyclic aromatic hydrocarbons (PAHs). Most of the degradation kinetics for PAHs by the indigenous microorganisms developed in soils can be fitted with the Logistic growth models. The microbial activities were relatively lower in the soils with the lowest and highest organic matter content, which were likely due to the nutrition limit and PAH sequestration. The microbial activities developed in humic acid (HA) were much higher than those developed in humin, which was demonstrated to be able to sequester organic pollutants stronger. The results suggested that the nutrition support and sequestration were the two major mechanisms, that soil organic matter influenced the development of microbial PAHs degradation potentials. - Research highlights: PAH degradation kinetics obey Logistic model. Degradation potentials depend on soil organic carbon content. Humin inhibits the development of PAH degradation activity. Nutrition support and sequestration regulate microbial degradation capacity. - Soil organic matter regulated PAH degradation potentials through nutrition support and sequestration.

  12. Effects of soil organic matter on the development of the microbial polycyclic aromatic hydrocarbons (PAHs) degradation potentials

    International Nuclear Information System (INIS)

    Yang, Y.; Zhang, N.; Xue, M.; Lu, S.T.; Tao, S.

    2011-01-01

    The microbial activity in soils was a critical factor governing the degradation of organic micro-pollutants. The present study was conducted to analyze the effects of soil organic matter on the development of degradation potentials for polycyclic aromatic hydrocarbons (PAHs). Most of the degradation kinetics for PAHs by the indigenous microorganisms developed in soils can be fitted with the Logistic growth models. The microbial activities were relatively lower in the soils with the lowest and highest organic matter content, which were likely due to the nutrition limit and PAH sequestration. The microbial activities developed in humic acid (HA) were much higher than those developed in humin, which was demonstrated to be able to sequester organic pollutants stronger. The results suggested that the nutrition support and sequestration were the two major mechanisms, that soil organic matter influenced the development of microbial PAHs degradation potentials. - Research highlights: → PAH degradation kinetics obey Logistic model. → Degradation potentials depend on soil organic carbon content. → Humin inhibits the development of PAH degradation activity. → Nutrition support and sequestration regulate microbial degradation capacity. - Soil organic matter regulated PAH degradation potentials through nutrition support and sequestration.

  13. Hierarchically multifunctional K-OMS-2/TiO2/Fe3O4 heterojunctions for the photocatalytic oxidation of humic acid under solar light irradiation.

    Science.gov (United States)

    Zhang, Tong; Yan, Xiaoli; Sun, Darren Delai

    2012-12-01

    A multifunctional heterojunctioned K-OMS-2/TiO(2)/Fe(3)O(4) (KTF) nanocomposite was successfully synthesized using a combination of hydrothermal and co-precipitation techniques. The resultant sample was characterized by XRD, FESEM, TEM, N(2) adsorption, XPS and VSM. Its photocatalytic activity was demonstrated in the photocatalytic degradation of humic acid (HA). Morphology characterization showed the hierarchical structure of the synthesized material, and XRD results revealed that both the rutile and anatase TiO(2) structures are present in the sample. The average pore diameters and BET surface area of the synthesized KTF heterojunctions were 40 nm and 134.42 m(2)/g, respectively. XPS spectra confirmed the presence of Fe(3)O(4) and TiO(2) in the synthesized material, and the valences of Mn were kept at +3 and +4 after the grafting of Fe(3)O(4) and TiO(2). The synthesized material showed good magnetic response and photocatalytic activity under simulated solar light irradiation, and 85.7% of HA was decomposed after 120 min in the presence of KTF nanocomposites. The reusability study suggested that the magnetic recovered material was stable enough for multiple recycling usages, verifying its potential application in water purification. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. The Effects of Drought Stress and Humic Acid on Morphological Traits, Yield and Anthocyanin of Roselle (Hibiscus sabdariffa L.

    Directory of Open Access Journals (Sweden)

    mojgan sanjarimijani

    2017-01-01

    Full Text Available Introduction Roselle (Hibiscus sabdariffa L. as a medicinal plant belongs to the Malvacea family. Their active ingredient increases under water stress. Humic acid bacteria derived from humus and other natural resources have hormonal effects and can improve nutrient absorption to enhance performance especially under stress conditions . Materials and methods This experiment was conducted in the research of agricultural education centre Jiroft in 2013. Field experiment was carried out as split plot design with three replications. Water deficit stress set as main factor with three levels (A1= Irrigation after 50, A2= 100 and A3= 150 mm evaporation from pan class A and humic acid was in four manners (B1= non humic acid, B2= once with Irrigation, B3= once with Irrigation + Once spraying, B4= once with Irrigation + twice Spraying. Humic acid was used to form Irrigation spray in order to arrange with compactness (10 kg.ha-1, (250 ml/100L. In late September, which coincides with the end of the heading, plant height, inflorescence length, number of branches, stem diameter, fresh and dry weight of plant, fresh and dry weight of sepals, were examined. Wagner method was used to measure anthocyanin content sepals (Wagner, 1979. Finally, data was analyzed using SAS 9.1 and means were compared by Duncan’s multiple range test at 5% level of probability. Results and discussion The analysis of variance showed that drought stress and humic acid had significant effect on growth parameters, vegetative and generative yield and anthocyanin. Drought stress decreased plant height, inflorescence length, stem diameterand fresh and dry weight sepals. The highest values of these traits was obtained in the first level of stress (50 mm evaporation from pan class A. Due to the reduction in mentioned properties, reducing the pressure tolerance and the subsequent reduction in drought conditions was considered as division and cell enlargement. The reduction in growth parameters

  15. The Effects of Drought Stress and Humic Acid on Morphological Traits, Yield and Anthocyanin of Roselle (Hibiscus sabdariffa L.

    Directory of Open Access Journals (Sweden)

    mojgan sanjarimijani

    2017-08-01

    Full Text Available Introduction Roselle (Hibiscus sabdariffa L. as a medicinal plant belongs to the Malvacea family. Their active ingredient increases under water stress. Humic acid bacteria derived from humus and other natural resources have hormonal effects and can improve nutrient absorption to enhance performance especially under stress conditions . Materials and methods This experiment was conducted in the research of agricultural education centre Jiroft in 2013. Field experiment was carried out as split plot design with three replications. Water deficit stress set as main factor with three levels (A1= Irrigation after 50, A2= 100 and A3= 150 mm evaporation from pan class A and humic acid was in four manners (B1= non humic acid, B2= once with Irrigation, B3= once with Irrigation + Once spraying, B4= once with Irrigation + twice Spraying. Humic acid was used to form Irrigation spray in order to arrange with compactness (10 kg.ha-1, (250 ml/100L. In late September, which coincides with the end of the heading, plant height, inflorescence length, number of branches, stem diameter, fresh and dry weight of plant, fresh and dry weight of sepals, were examined. Wagner method was used to measure anthocyanin content sepals (Wagner, 1979. Finally, data was analyzed using SAS 9.1 and means were compared by Duncan’s multiple range test at 5% level of probability. Results and discussion The analysis of variance showed that drought stress and humic acid had significant effect on growth parameters, vegetative and generative yield and anthocyanin. Drought stress decreased plant height, inflorescence length, stem diameterand fresh and dry weight sepals. The highest values of these traits was obtained in the first level of stress (50 mm evaporation from pan class A. Due to the reduction in mentioned properties, reducing the pressure tolerance and the subsequent reduction in drought conditions was considered as division and cell enlargement. The reduction in growth parameters

  16. Laccase-mediated transformation of triclosan in aqueous solution with metal cations and humic acid.

    Science.gov (United States)

    Sun, Kai; Kang, Fuxing; Waigi, Michael Gatheru; Gao, Yanzheng; Huang, Qingguo

    2017-01-01

    Triclosan (TCS) is a broad-spectrum antimicrobial agent that is found extensively in natural aquatic environments. Enzyme-catalyzed oxidative coupling reactions (ECOCRs) can be used to remove TCS in aqueous solution, but there is limited information available to indicate how metal cations (MCs) and natural organic matter (NOM) influence the environmental fate of TCS during laccase-mediated ECOCRs. In this study, we demonstrated that the naturally occurring laccase from Pleurotus ostreatus was effective in removing TCS during ECOCRs, and the oligomerization of TCS was identified as the dominant reaction pathway by high-resolution mass spectrometry (HRMS). The growth inhibition studies of green algae (Chlamydomonas reinhardtii and Scenedesmus obliquus) proved that laccase-mediated ECOCRs could effectively reduce the toxicity of TCS. The presence of dissolved MCs (Mn 2+ , Al 3+ , Ca 2+ , Cu 2+ , and Fe 2+ ions) influenced the removal and transformation of TCS via different mechanisms. Additionally, the transformation of TCS in systems with NOM derived from humic acid (HA) was hindered, and the apparent pseudo first-order kinetics rate constants (k) for TCS decreased as the HA concentration increased, which likely corresponded to the combined effect of both noncovalent (sorption) and covalent binding between TCS and humic molecules. Our results provide a novel insight into the fate and transformation of TCS by laccase-mediated ECOCRs in natural aquatic environments in the presence of MCs and NOM. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. 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.

  18. Combining spectroscopic and potentiometric approaches to characterize competitive binding to humic substances

    International Nuclear Information System (INIS)

    Marang, L.; Reiller, P.E.; Marang, L.; Benedetti, M. F.; Marang, L.; Eidner, S.; Kumke, M.

    2008-01-01

    In an area that contains high concentrations of natural organic matter, it is expected that it plays an important role on the behavior of rare earth elements (REE), like europium, and of trivalent actinides. Competitive interactions with H + , inorganic species, major cations, e.g. Ca(II) or Mg(II), could influence these metals transport and bioavailability. Competitive experiments between cations, which can bind differently to humic substances and Eu 3+ , will 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 for Ca 2+ , Cu 2+ , and Eu 3+ obtained from competitive binding experiments using Ca 2+ or Cu 2+ ion selective electrodes were used to model time-resolved laser fluorescence spectroscopy (TRLFS) measurements. Eu 3+ and Cu 2+ are in direct competition for the same type of sites, whereas Ca 2+ has an indirect influence through electrostatic binding. (authors)

  19. Effects of humic acid on the interactions between zinc oxide nanoparticles and bacterial biofilms.

    Science.gov (United States)

    Ouyang, Kai; Yu, Xiao-Ying; Zhu, Yunlin; Gao, Chunhui; Huang, Qiaoyun; Cai, Peng

    2017-12-01

    The effects of humic acid (HA) on interactions between ZnO nanoparticles (ZnO NPs) and Pseudomonas putida KT2440 biofilms at different maturity stages were investigated. Three stages of biofilm development were identified according to bacterial adenosine triphosphate (ATP) activity associated with biofilm development process. In the initial biofilm stage 1, the ATP content of bacteria was reduced by more than 90% when biofilms were exposed to ZnO NPs. However, in the mature biofilm stages 2 and 3, the ATP content was only slightly decreased. Biofilms at stage 3 exhibited less susceptibility to ZnO NPs than biofilms at stage 2. These results suggest that more mature biofilms have a significantly higher tolerance to ZnO NPs compared to young biofilms. In addition, biofilms with intact extracellular polymeric substances (EPS) showed higher tolerance to ZnO NPs than those without EPS, indicating that EPS play a key role in alleviating the toxic effects of ZnO NPs. In both pure ZnO NPs and ZnO-HA mixtures, dissolved Zn 2+ originating from the NPs significantly contributed to the overall toxicity. The presence of HA dramatically decreased the toxicity of ZnO NPs due to the binding of Zn 2+ on HA. The combined results from this work suggest that the biofilm maturity stages and environmental constituents (such as humic acid) are important factors to consider when evaluating potential risks of NPs to ecological systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. How many carboxyl groups does an average molecule of humic-like substances contain?

    Directory of Open Access Journals (Sweden)

    I. Salma

    2008-10-01

    Full Text Available The carboxyl groups of atmospheric humic-like substances (HULIS are of special interest because they influence the solubility in water, affect the water activity and surface tension of droplets in the air, and allow formation of chelates with biologically active elements. Experimentally determined abundances of the carboxyl group within HULIS by functional group analysis are consistent with our knowledge on the average molecular mass of HULIS if the number of dissociable carboxyl groups is assumed to be rather small. The best agreement between the average molecular mass derived from the existing abundance data and the average molecular mass published earlier occurs for assuming approximately one dissociable carboxyl group only. This implies that HULIS can not be regarded as polycarboxilic acid in diluted solutions. The average molecular mass of HULIS derived from our electrochemical measurements with the assumption of one dissociable carboxyl group or equivalently, one dissociable sulphate ester per molecule ranges from 250 to 310 Da. It was concluded that HULIS are a moderately strong/weak acid with a dissociation constant of about pK=3.4, which fits well into the interval represented by fulvic and humic acids. The mean number of dissociable hydrogen (i.e. of carboxyl groups and sulphate esters jointly in HULIS molecules was refined to be between 1.1 and 1.4 in acidic solutions.

  1. A comparative chemical-structural study of fossil humic acids and those extracted from urban wastes

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, C.; Hernandez, T.; Costa, F.; Ceccanti, B.; Polo, A. (Centro de Edafologia y Biologia Aplicada del Segura, Murcia (Spain))

    1992-05-01

    Chemical-structural features of commercial humic acids (HAs) from leonardite or lignite were studied and the data obtained were compared with those of humic acids extracted from composted urban wastes. The greatest differences showed by the elemental analysis between the three HAs were in N and H contents, both of which diminished with the oxidation degree of the starting materials. FTIR spectra did not show differences between HAs from evolved materials such as leonardite or lignite. However, differences were found between these HAs and those extracted from composts of urban wastes, which showed a greater aliphatic character and a more pronounced peak in the absorption band attributed to secondary amides and in that of carbohydrates. The {sup 13}C-NMR spectra were similar for both HAs from leonardite regardless of their oxidation degree. The percentage of aromaticity of these HAs was 45%. The spectra of compost HAs showed a low aromaticity degree for these HAs as a consequence of the pronounced peak appearing at 73 ppm corresponding to carbon of carbohydrates and/or polyalcohols and aminoacids. Py-GC revealed a high content of benzene and toluene in all the commercial HAs. The values of these fragments as well as those of the ratios between pyrolitic fragments, used as humification index for soils, were the highest in the HA extracted from the more oxidized leonardite. 17 refs., 1 fig., 5 tabs.

  2. SOLUBILIZATION OF POTASSIUM FROM ALTERNATIVE ROCKS BY HUMIC AND CITRIC ACIDS AND COFFEE HUSK

    Directory of Open Access Journals (Sweden)

    Rodrigo Souza Pessoa

    2015-12-01

    Full Text Available ABSTRACT Brazil imports most of the potassium that it consumes in agriculture, however, such huge external dependence can be minimized with the use of alternative local K bearing rocks. This experiment was conducted with the objective of evaluating the solubility of nepheline syenite and glauconite as a function of three organic matrices, humic acid, citric acid and coffee husk. Incubation of low grade K rocks and organic matrices were done in laboratory conditions, in a completely randomized design. Each rock was mixed with five different doses of each organic matrix and the potassium solubilized was measured periodically, during 180 days. Regardless of the organic matrix and its dose investigated, nepheline syenite samples released more K than the modified glauconite. Soluble K increased as the incubation time increased and its release was greater as the organic matrix dose increased. There was more soluble K when the coffee husk was mixed with the potassic rocks, in relation to the humic and citric acids.

  3. Humic acids: Structural properties and multiple functionalities for novel technological developments.

    Science.gov (United States)

    de Melo, Bruna Alice Gomes; Motta, Fernanda Lopes; Santana, Maria Helena Andrade

    2016-05-01

    Humic acids (HAs) are macromolecules that comprise humic substances (HS), which are organic matter distributed in terrestrial soil, natural water, and sediment. HAs differ from the other HS fractions (fulvic acid and humins) in that they are soluble in alkaline media, partially soluble in water, and insoluble in acidic media. Due to their amphiphilic character, HAs form micelle-like structures in neutral to acidic conditions, which are useful in agriculture, pollution remediation, medicine and pharmaceuticals. HAs have undefined compositions that vary according to the origin, process of obtainment, and functional groups present in their structures, such as quinones, phenols, and carboxylic acids. Quinones are responsible for the formation of reactive oxygen species (ROS) in HAs, which are useful for wound healing and have fungicidal/bactericidal properties. Phenols and carboxylic acids deprotonate in neutral and alkaline media and are responsible for various other functions, such as the antioxidant and anti-inflammatory properties of HAs. In particular, the presence of phenolic groups in HAs provides antioxidant properties due to their free radical scavenging capacity. This paper describes the main multifunctionalities of HAs associated with their structures and properties, focusing on human health applications, and we note perspectives that may lead to novel technological developments. To the best of our knowledge, this is the first review to address this topic from this approach. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Natural organochlorine in humic soils. GC and GC/MS studies of soil pyrolysates

    Science.gov (United States)

    de Lijser, H. J. Peter; Erkelens, Corrie; Knol, Adri; Pool, Wim; de Leer, Ed W. B.

    Organic Halogen (OX) matter of natural origin in soils forms an integral part of the macromolecular humic materials and, therefore, it cannot be removed by simple washing and extracting processes. In this study pyrolysis at 400°C in a nitrogen atmosphere was used to break down the humic macromolecules to gas chromatographable compounds, which were collected in a cold trap system. According to coulorimetric analysis, 10-60% of the original soil OX was removed by the pyrolysis process but only a small part of the OX removed (2-40%) was collected in the cold trap system. The bulk of the OX was found in a precipitate that was formed between the furnace and the cold trap system. Analysis of the pyrolysates with GC/ECD indicated the presence of organohalogen compounds. GC/MS-NCI/SIM gave evidence for the presence of at least 20 different organochlorine compounds. Identification of individual organochlorine compounds with GC/MS and GC/MS-SIM was not successful, possibly due to the relatively low concentrations of these compounds and the overlap with other major non-chlorinated components. GC/MS-CNL indicated the presence of dichloropropane or chlorobenzene, and chlorophenol as of several unidentified chloroalkanes and/or chloroalkenes.

  5. Chemistry and transport of soluble humic substances in forested watersheds of the Adirondack Park, New York

    Science.gov (United States)

    Cronan, C.S.; Aiken, G.R.

    1985-01-01

    Studies were conducted in conjunction with the Integrated Lake-Watershed Acidification Study (ILWAS) to examine the chemistry and leaching patterns of soluble humic substances in forested watersheds of the Adirondack region. During the summer growing season, mean dissolved organic carbon (DOC) concentrations in the ILWAS watersheds ranged from 21-32 mg C l-1 in O/A horizon leachates, from 5-7 mg C l-1 in B horizon leachates, from 2-4 mg C l-1 in groundwater solutions, from 6-8 mg C l-1 in first order streams, from 3-8 mg C l-1 in lake inlets, and from 2-7 mg C l-1 in lake outlets. During the winter, mean DOC concentrations dropped significantly in the upper soil profile. Soil solutions from mixed and coniferous stands contained as much as twice the DOC concentration of lysimeter samples from hardwood stands. Results of DOC fractionation analysis showed that hydrophobia and hydrophilic acids dominate the organic solute composition of natural waters in these watersheds. Charge balance and titration results indicated that the general acid-base characteristics of the dissolved humic mixture in these natural waters can be accounted for by a model organic acid having an averagepKa of 3.85, an average charge density of 4-5 ??eq mg-1 C at ambient pH, and a total of 6-7 meq COOH per gram carbon. ?? 1985.

  6. Isotopic variations in the nitrogen of natural humic and bituminous organic substances

    International Nuclear Information System (INIS)

    Stiehl, G.; Lehmann, M.

    1980-01-01

    delta 15 N-values and nitrogen contents of a series of humic and bituminous organic sediments of different ranks were determined. The change of the isotopic abundance of nitrogen was investigated during heating in model experiments, using a gas flame coal. In the case of humic carbon coals the relative nitrogen contents vary from 0.8 to 1.4% and the delta 15 N-values from + 3.5 to + 6.3 parts per thousand increasing from the brown coal to anthracite ranks. During the coalification process both the delta 15 N-values and the relative nitrogen contents do not vary continuously with the rank, but pass through maxima and minima. Model experiments using a gas flame coal show the same trend. Nitrogen with delta 15 N-values of + 2.8 or -7 parts per thousand was released in pyrolysis experiments, applying a gas flame coal and a steam coal at temperatures of 650 and 1000 0 C, respectively. The investigated bituminous sediments yielded relative amounts of 0.1 to 0.8% with delta 15 N-values of + 4.2 to + 10.7 parts per thousand. The obtained results are discussed with respect to the elucidation of nitrogen genesis in natural gas deposits. (author)

  7. 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.

  8. HPLC studies of aquatic humic compounds and complexes from the Drigg Research Site, Cumbria

    International Nuclear Information System (INIS)

    Smith, B.

    1991-01-01

    This report describes an investigation into the applicability of high performance liquid chromatographic techniques for the separation of the complex mixtures of organic acids commonly found in groundwaters. This work has shown that reverse phase ion-pair chromatography using a large pore stationary phase can be successfully applied to humic material in both natural and concentrated groundwater from the Drigg Research Site. The methodology separates the organic species into a number of well resolved components the majority of which have a molecular weight of greater than 500 Dalton. Separations obtained have been qualitatively and quantitatively analysed using a Diode array spectrophotometer. The components in excess of 500 Dalton show UV absorption spectra similar to humic and fulvic acids where as the component with a molecular weight of less than 500 Dalton shows a sharp UV absorption cutoff at 230 nm. It was noted that this component was not removed by passage through DEAEA cellulose. Reverse phase HPLC was also investigated, and results were found to be consistent with a separation based on an ion-repulsion/size exclusion mechanism. It was concluded that any separation based on this mechanism is likely to suffer from poor inter run reproducibility and must therefore be discounted as a suitable method. Similarly, ion-suppression reverse phase was shown to be equally impracticable, requiring a mobile phase pH of less than 2 to obtain separation (this low pH renders a silica based stationary phase unstable). (author)

  9. Extraction Kinetics and Molecular Size Fractionation of Humic Substances From Two Brazilian Soils

    Directory of Open Access Journals (Sweden)

    Dick Deborah Pinheiro

    1999-01-01

    Full Text Available In the present study, the extraction behaviour of humic substances (HS from an Oxisol and a Mollisol from South Brazil, by using 0.1 and 0.5 mol L-1 NaOH and 0.15 mol L-1 neutral pyrophosphate solutions, respectively, was systematically studied. The kinetics and efficiency of HS extraction were evaluated by means of UV/Vis spectroscopy. The isolated humic acids (HA and fulvic acids (FA were size-classified by multistage ultrafiltration (six fractions in the molecular weight range of 1 to 100 kDa. The obtained data show that the HS extraction yield depended not only on the extractant, but also on the soil type. Within 3 h approximately 90% of the soluble HS could be extracted following complex extraction kinetics by both methods and none or little structural modification was verified as observed from their stable extinction ratio E350/E550. In the Mollisol the pyrophosphate extraction was more effective, suggesting that a great part of HS occurred as macromolecules bonded to clay minerals and aggregated between themselves through cationic bridges. In the Oxisol a higher HS yield was verified with the alkaline method, presumably due to HS fixation onto the oxide surface by H-bonds and/or surface complexation reactions. In general, HS extracted by the pyrophosphate procedure showed higher molecular weights than those extracted by NaOH.

  10. Alleviation of iron toxicity in Schinus terebinthifolius Raddi (Anacardiaceae) by humic substances.

    Science.gov (United States)

    Dobbss, Leonardo Barros; Dos Santos, Tamires Cruz; Pittarello, Marco; de Souza, Sávio Bastos; Ramos, Alessandro Coutinho; Busato, Jader Galba

    2018-01-19

    One of the industrial pillars of Espírito Santo state, South East of Brazil, is iron-mining products processing. This activity brings to a high level of coastal pollution due to deposition of iron particulate on fragile ecosystems as mangroves and restinga. Schinus therebinthifolius (aroeira) is a widespread restinga species. This work tested iron toxicity alleviation by vermicompost humic substances (HS) added to aroeira seedlings in hydroponic conditions. Catalase, peroxidase, and ascorbate peroxidase are antioxidant enzymes that work as reactive oxygen species (ROS) scavengers: they increase their activity as an answer to ROS concentration rise that is the consequence of metal accumulation or humic substance stimulation. S. terebinthifolius seedlings treated with HS and Fe augmented their antioxidant enzyme activities significantly less than seedlings treated separately with HS and Fe; their significantly lower Fe accumulation and the slight increase of root and leaf area confirm the biostimulating effect of HS and their role in blocking Fe excess outside the roots. The use of HS can be useful for the recovery of areas contaminated by heavy metals.

  11. 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.

  12. Study of stability of humic acids from soil and peat irradiated by gamma rays

    International Nuclear Information System (INIS)

    Silva, Wilson Tadeu Lopes da

    1995-01-01

    Humic acids samples (one deriving from a sedimentary soil and other from a peat), in aqueous media, were irradiated with gamma rays, in doses of 10, 50 and 100 kGy, in order to understand their chemical behavior after the irradiation. The material, before and after irradiation, was analyzed by Elemental Analysis, Functional Groups (carboxylic acids and phenols), UV/Vis Spectroscopy (E 4 /E 6 ratio), IR spectroscopy, CO 2 content and Gel permeation Chromatography (GPC) ). The Elemental Analysis showed the humic acid derived from a peat had a most percentage quantity of Carbon and Hydrogen than the material from a sedimentary soil. From the UV/Vis Spectroscopy, it was observed a decrease of E 4 /E 6 ratio with an increase of the applied dose. The data from GPC are in agreement with this. The results showed that the molecular weight of the material increased by exposing it to a larger radiolitical dose. The peat material was less affected by the gamma radiation than the soil material. The carboxylic groups were responsible by radiochemical behavior of the material. (author)

  13. The Infrared Spectrum Analysis on Compound Urea with Humic Acid Extracted from Weathered Coal

    Directory of Open Access Journals (Sweden)

    LIU Zeng-bing

    2014-10-01

    Full Text Available After treated with alkaline solution and then centrifuged, weathered coal was divided into water-soluble humic acid and deposi- tion. Then as the urea synergist materials, weathering coal, humic acid and deposition were respectively mixed with melted urea according to different proportion to produce three kinds of compound urea. The infrared spectrum analysis(IRof above synergist materials and products found that after being treated with alkaline, weathered coal was reduced carbon-carbon bond amount and its carbon chain became shorten,more active functional group happened to the HA extracts. While the FR deposition showed carbon-carbon bond reduced and parts of amine or amide structure were formed. Additionally, the IR also found that during the compound of urea with the synergists, the formation of carbon-carbon triple bond, the broken of accumulated double bonds, the shorten of carbon chain, and the formation of more double bond and stablestructure were observed. However, the different synergists mixed with urea brought out different IR characters.

  14. Binding of polycyclic aromatic hydrocarbons by humic acids formed during composting

    International Nuclear Information System (INIS)

    Plaza, Cesar; Xing Baoshan; Fernandez, Jose M.; Senesi, Nicola; Polo, Alfredo

    2009-01-01

    Binding of two model polycyclic aromatic hydrocarbons (PAHs), phenanthrene and pyrene, by humic acids (HAs) isolated from an organic substrate at different stages of composting and a soil was investigated using a batch fluorescence quenching method and the modified Freundlich model. With respect to soil HA, the organic substrate HA fractions were characterized by larger binding affinities for both phenanthrene and pyrene. Further, isotherm deviation from linearity was larger for soil HA than for organic substrate HAs, indicating a larger heterogeneity of binding sites in the former. The composting process decreased the binding affinity and increased the heterogeneity of binding sites of HAs. The changes undergone by the HA fraction during composting may be expected to contribute to facilitate microbial accessibility to PAHs. The results obtained also suggest that bioremediation of PAH-contaminated soils with matured compost, rather than with fresh organic amendments, may result in faster and more effective cleanup. - Composting of organic materials decreases the binding affinity of the humic acid fraction for polycyclic aromatic hydrocarbons

  15. [The investigation of humic acid by surface-enhanced Raman spectroscopy].

    Science.gov (United States)

    Zhang, Wen-Juan; Li, Ying; Guo, Jin-Jia; Xiao, Qiong; Yu, Li

    2013-05-01

    Humic acid (HA), which are organic compounds widely existing in the oceans, rivers and soil, has important significance for the environmental monitoring of soil and water. In this paper, ai ming at the problem of Surface-enhanced Raman Spectroscopy (SERS) applying for HA detection in water, the characteristics of the humic acid on silver colloids was studied by means of SERS. The influence of laser irradiation time, HA concentrations and pH value on the surface-enhanced effects of HA were investigated. The experimental results show that the SERS spectra of HA is ideal when the laser irradiation time between 20-30 min. The SERS of different HA concentrations was detected. It was found that the relative intensity at 1 379 cm(-1) increased as a linear function of the concentration of HA with correlation coefficient R2 of 0.993. The SERS of HA was found to be very sensitive to pH, the SERS spectra of HA was very weak at neutral pH, but at acidic pH and alkaline pH a remarkable increase of SERS intensity occurred. The SERS of HA in running water was detected too. The experimental results show that it is feasible to detect HA in natural water by means of surface-enhanced Raman spectroscopy.

  16. Spectroscopy study of silver nanoparticles fabrication using synthetic humic substances and their antimicrobial activity

    Science.gov (United States)

    Litvin, Valentina A.; Minaev, Boris F.

    2013-05-01

    In this present study, silver nanoparticles were synthesized using synthetic humic substances (HSs) as reducing and stabilizing agents. Preference of synthetic HSs over natural humic matter is determined by a standardization problem resolution of the product due to the strict control of conditions of the synthetic HSs formation. It allows to receive the silver nanoparticles with the standardized biologically-active protective shell that is very important for their use, mainly in medicine. The concentration of sodium hydroxide, synthetic HSs, silver nitrate and temperature employed in the synthesis process are optimized to attain better yield, controlled size and stability by means of UV-visible technique. In the optimal reaction conditions the concentrated silver colloids (55 mM) with 99.99% yield are obtained which were stable for more than 1 year under ambient conditions. The received silver nanoparticles are characterized by UV-visible spectroscopy, X-ray diffraction (XRD), FT-IR spectroscopy and transmission electron microscopy (TEM). The antimicrobial activity of silver nanoparticles against fungal and bacterial strains is also shown.

  17. Effects of supplemental humic acid on ruminal fermentation and blood variables in rams

    Directory of Open Access Journals (Sweden)

    Nurten Galip

    Full Text Available In this study, we particularly aimed to research the effect of supplemental humic acid on ruminal fermentation and blood variables in rams. A trial was conducted to evaluate the effect of humic acid (HA on protozoa count, percentages of different protozoa types and blood parameters. Three male Kivircik rams with ruminal cannula were used in a Latin square design, during 22 days periods (15 days for adaptation, 7 days for collection. They received 0 control group (CG, 5 g/day or 10 g/day of HA (HA5, HA10, assay groups. HA were added to the ration with grain diet. Ration was consisted of 5% grain diet and 95 % alfalfa hay. Rumen contents collected before, 3h and 6h after morning feeding on days 1 and 7 in each collection period were analyzed. Blood samples were also collected the same days. No significant difference in biochemical and hematological parameters (except eosinophils levels, P<0.05, variables of ruminal fluid (except sodium levels before feeding and species of rumen protozoa organism (except the percentage Epidinium spp. were evidenced with the addition of HA. In conclusion, we think that they might have been true the widely use in animal food of humates which don’t have any negative effect on biochemical and hematological parameters in particular.

  18. Reducing capacities and redox potentials of humic substances extracted from sewage sludge.

    Science.gov (United States)

    Yang, Zhen; Du, Mengchan; Jiang, Jie

    2016-02-01

    Humic substances (HS) are redox active organic materials that can be extracted from sewage sludge generated in wastewater treatment processes. Due to the poor understanding of reducing capacity, redox potentials and redox active functional groups of HS in sewage sludge, the potential contribution of sludge HS in transformation of wastewater contaminants is unclear. In the present study, the number of electrons donated or accepted by sewage sludge HS were quantified before and after reduction by iron compounds that possess different redox potentials and defined as the reducing capacity of the sewage sludge. In contrast to previous studies of soil and commercial humic acids (HA), reduced sludge HA showed a lower reducing capacity than that of native HA, which implies formation of semiquinone radicals since the semiquinone radical/hydroquinone pair has a much higher redox potential than the quinone/hydroquinone pair. It is novel that reducing capacities of sludge HA were determined in the redox potential range from -314 to 430 mV. The formation of semiquinone radicals formed during the reduction of quinone moieties in sludge HA is shown by three-dimensional excitation/emission matrix fluorescence spectroscopies information, increasing fluorescence intensities and blue-shifting of the excitation/emission peak of reduced sludge HA. Knowledge of sludge HS redox potentials and corresponding reducing capacities makes it possible to predict the transformation of redox active pollutants and facilitate manipulation and optimization of sludge loading wastewater treatment processes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Using Spectrophotometric Titrations To Characterize Humic Acid Reactivity at Environmental Concentrations

    International Nuclear Information System (INIS)

    Janot, N.; Benedetti, M. F.; Janot, N.; Reiller, P. E.; Korshin, G. V.

    2010-01-01

    Potentiometric titration is a common method to characterize dissolved organic matter (DOM) reactivity. Because of the sensitivity of pH electrodes, it is necessary to work with very high DOM (≥1 g/L) concentrations that are unrealistic compared to those found in natural waters (0. 1 to 100 mg/L). To obtain proton binding data for concentrations closer to environmental values, spectroscopic titration methodology is a viable alternative to traditional potentiometric titrations. Spectrophotometric titrations and UV visible spectra of a diluted solution of purified Aldrich humic acid (5 mg(DOC)/L) are used to estimate changes in proton binding moieties as function of pH and ionic strength after calculation of differential absorbance spectra variations. After electrostatic correction of spectrophotometric data, there is a linear operational correlation between spectrophotometric and potentiometric data which can be used as a transfer function between the two properties. Spectrophotometric titrations are then used to determine the changes of humic acid protonation after adsorption onto alpha-alumina. (authors)

  20. Aggregate Stability in Soil with Humic and Histic Horizons in a Toposequence under Araucaria Forest

    Directory of Open Access Journals (Sweden)

    Daniel Hanke

    Full Text Available ABSTRACT Aggregate stability is one of the most important factors in soil conservation and maintenance of soil environmental functions. The objective of this study was to investigate the aggregate stability mechanisms related to chemical composition of organic matter in soil profiles with humic and histic horizons in a toposequence under Araucaria moist forest in southern Brazil. The soils sampled were classified as Humic Hapludox (highest position, Fluvaquentic Humaquepts (lowest slope position, and Typic Haplosaprists (floodplain. The C and N contents were determined in bulk soil samples. The chemical composition of soil organic matter was evaluated by infrared spectroscopy. Aggregate stability was determined by applying increasing levels of ultrasound energy. Carbon content increased from the top of the slope to the alluvial plain. Higher ultrasonic energy values for clay dispersion were observed in the C-rich soils in the lower landscape positions, indicating that organic compounds play an important role in the structural stabilization of these profiles. Both aliphatic and carbohydrate-like structures were pertinent to aggregate stability. In the Oxisol, organo-mineral interaction between carbohydrates and the clay mineral surface was the most important mechanism affecting aggregation. In soils with a higher C content (Humaquepts and Haplosaprists, stabilization is predominantly conferred by the aliphatic groups, which is probably due to the structural protection offered by these hydrophobic organic groups.

  1. Effects of supplemental humic acid on ruminal fermentation and blood variables in rams

    Directory of Open Access Journals (Sweden)

    Umit Polat

    2010-11-01

    Full Text Available In this study, we particularly aimed to research the effect of supplemental humic acid on ruminal fermentation and blood variables in rams. A trial was conducted to evaluate the effect of humic acid (HA on protozoa count, percentages of different protozoa types and blood parameters. Three male Kivircik rams with ruminal cannula were used in a Latin square design, during 22 days periods (15 days for adaptation, 7 days for collection. They received 0 control group (CG, 5 g/day or 10 g/day of HA (HA5, HA10, assay groups. HA were added to the ration with grain diet. Ration was consisted of 5 % grain diet and 95 % alfalfa hay. Rumen contents collected before and, 3h and 6h after morning feeding on days 1 and 7 in each collection period were analyzed. Blood samples were also collected the same days. No significant difference in biochemical and hematological parameters (except eosinophils levels, P, variables of ruminal fluid (except sodium levels before feeding and species of rumen protozoa organism (except the percentage Epidinium spp. were evidenced with the addition of HA. In conclusion, we think that they might have been true the widely use in animal food of humates which don’t have any negative effect on biochemical and hematological parameters in particular. 

  2. Multi-walled carbon nanotube dispersion by the adsorbed humic acids with different chemical structures.

    Science.gov (United States)

    Zhang, Di; Pan, Bo; Cook, Robert L; Xing, Baoshan

    2015-01-01

    Dissolved humic acid (disHA) is effective for suspending carbon nanotubes (CNTs), but the suspending mechanism is still unclear. This study used bleached and hydrolyzed humic acids as suspending agents to investigate effects of chemical structures on CNTs suspension. The adsorption of aromatic moieties enriched disHA to CNTs was lower than aliphatic components-enriched disHA, but the former was better at suspending CNTs. These findings led to the development of a model, in which disHA with aromatic structures results in stable suspension of CNTs due to stronger steric hindrance. Because of their flexible structures, aliphatic components-enriched disHA molecules easily conformed to CNTs leading to higher adsorption to CNTs but weaker steric hindrance between CNTs. Therefore, the bridging and less suspension of CNTs was observed. This study emphasizes that suspending CNTs by disHA is not only controlled by the adsorbed amount of disHA, but also the chemical nature of disHA.

  3. Use of biochar as bulking agent for the composting of poultry manure: effect on organic matter degradation and humification.

    Science.gov (United States)

    Dias, Bruno O; Silva, Carlos A; Higashikawa, Fábio S; Roig, Asunción; Sánchez-Monedero, Miguel A

    2010-02-01

    The aim of this study was to evaluate the use of biochar (produced by slow pyrolysis of Eucalyptus grandis biomass) as bulking agent for the composting of poultry manure. Three composting mixtures were prepared by the turned-pile system by mixing poultry manure with different organic wastes used as bulking agent (biochar, coffee husk and sawdust) in a proportion of 1:1 (fresh weight). Despite the inert nature of biochar, the composting mixture prepared with biochar underwent an organic matter degradation of 70% of the initial content. The organic matter of the poultry manure-biochar mixture was characterised by a high polymerisation degree of the humic-like substances, with a relative high proportion of humic acids in relation to fulvic acids. At the end of the composting process, the humic acid fraction represented more than 90% of the alkali extractable fraction, reflecting the intense humification of this material. Enrichment of poultry manure with biochar reduced the losses of nitrogen in the mature composts, although the use of sawdust would be more efficient in preserving the organic matter and nitrogen in the mature compost.

  4. - and Cross-Polarization 13C NMR Evidence of Alterations in Molecular Composition of Humic Substances Following Afforestation with Eucalypt in Distinct Brazilian Biomes

    Science.gov (United States)

    Silva, I. R.; Soares, E. M.; Schmidt-Rohr, K.; Novais, R.; Barros, N.; Fernandes, S.

    2010-12-01

    The effect of planting fast growing tree species on SOM quality in tropical regions has been overlooked. In the present study 13C-NMR approaches were used to evaluate the impact of eucalypt cultivation on humic and fulvic acids molecular composition. The results indicate that the replacement of native vegetation by eucalypt plantations increased the relative contribution of aliphatic groups in HA from soils previously under Atlantic Forest, Grassland, and the Cerrado (Curvelo site only). The same trend was observed for FA, except in the Curvelo site. A trend for degradation and smaller contribution of O-alkyl C (carbohydrates) in HA was observed in soils under eucalyptus in Atlantic Forest and Cerrado. For FA such decreases were seen in Cerrado and Grassland biomes after eucalypt planting. In the area cultivated with pasture in the Atlantic Forest biome and in the Grassland soil, the largest contributions of lignin-derived compounds were detected in HA. The HA from the Cerrado at the Curvelo site, where the woody vegetation is virtually devoid of grassy species, showed the lowest intensity of lignin signal then those from the Cerrado sensu stricto in Itacambira, where grass species are more abundant. At our study sites, charred material are most likely derived from burning of the native vegetation, as naturally occurs in the Cerrado region, or anthropogenic fires in the Grassland biome. Burning of harvest residues in eucalypt fields was also a common practice in the early rotations. The replacement of native vegetation by eucalypt plantations increases the relative contribution of nonpolar alkyl groups in HA from soils previously under Atlantic Forest, Grassland, and the Cerrado (Curvelo site only) biomes. There is evidence of substantial contribution of lignin-derived C to HA and FA, especially in sites planted with Brachiaria sp pastures. Eucalypt introduction decreases the relative contribution of carbohydrates in HA and FA. 13C DP/MAS NMR functional groups in

  5. Structural changes of humic acids from sinking organic matter and surface sediments investigated by advanced solid-state NMR: Insights into sources, preservation and molecularly uncharacterized components

    Science.gov (United States)

    Mao, Jingdong; Tremblay, Luc; Gagné, Jean-Pierre

    2011-12-01

    Knowledge of the structural changes that particulate organic matter (POM) undergoes in natural systems is essential for determining its reactivity and fate. In the present study, we used advanced solid-state NMR techniques to investigate the chemical structures of sinking particulate matter collected at different depths as well as humic acids (HAs) extracted from these samples and underlying sediments from the Saguenay Fjord and the St. Lawrence Lower Estuary (Canada). Compared to bulk POM, HAs contain more non-polar alkyls, aromatics, and aromatic C-O, but less carbohydrates (or carbohydrate-like structures). In the two locations studied, the C and N contents of the samples (POM and HAs) decreased with depth and after deposition onto sediments, leaving N-poor but O-enriched HAs and suggesting the involvement of partial oxidation reactions during POM microbial degradation. Advanced NMR techniques revealed that, compared to the water-column HAs, sedimentary HAs contained more protonated aromatics, non-protonated aromatics, aromatic C-O, carbohydrates (excluding anomerics), anomerics, OC q, O-C q-O, OCH, and OCH 3 groups, but less non-polar alkyls, NCH, and mobile CH 2 groups. These results are consistent with the relatively high reactivity of lipids and proteins or peptides. In contrast, carbohydrate-like structures were selectively preserved and appeared to be involved in substitution and copolymerization reactions. Some of these trends support the selective degradation (or selective preservation) theory. The results provide insights into mechanisms that likely contribute to the preservation of POM and the formation of molecules that escape characterization by traditional methods. Despite the depletion of non-polar alkyls with depth in HAs, a significant portion of their general structure survived and can be assigned to a model phospholipid. In addition, little changes in the connectivities of different functional groups were observed. Substituted and copolymerized

  6. Microwave-Enhanced Photolysis of Norfloxacin: Kinetics, Matrix Effects, and Degradation Pathways.

    Science.gov (United States)

    Liao, Wenchao; Sharma, Virender K; Xu, Su; Li, Qingsong; Wang, Lei

    2017-12-14

    Degradation of norfloxacin (NOR) was studied using a combination of microwave and UV irradiation methods (MW/UV process). Remarkable synergistic effect was found between MW and UV light. The removal rate with the MW/UV process was much faster than that with UV light irradiation only. Degradation of NOR followed second-order kinetics and ~72% of NOR could be removed in the first 5 min of MW/UV reaction. Influence of inorganic ions (cations (K⁺, Mg 2+ , Ca 2+ , Cu 2+ ) and anions (Cl - , SO₄ 2- , NO₃ - , CO₃ 2- )), humic acid (HA) and surfactants (cation, anion, and non-ionic) on the degradation of NOR by the MW/UV process was investigated. Among the ions, Cu 2+ and NO₃ - ions inhibited the degradation of NOR. The presence of HA and surfactants in water showed a slight inhibition on the NOR removal. Furthermore, the NOR degradation in the MW/UV process was primarily caused by the ·OH-photosensitization steps. Seven intermediates formed by the oxidation of NOR were identified and three reaction pathways were proposed. Removals of NOR in tap water (TW), synthetic wastewater (WW), river water (RW), and seawater (SW) were also studied, which demonstrated that the MW/UV process was an effective oxidation technology for degrading fluoroquinolone antibiotics in different water matrices.

  7. Microwave-Enhanced Photolysis of Norfloxacin: Kinetics, Matrix Effects, and Degradation Pathways

    Directory of Open Access Journals (Sweden)

    Wenchao Liao

    2017-12-01

    Full Text Available Degradation of norfloxacin (NOR was studied using a combination of microwave and UV irradiation methods (MW/UV process. Remarkable synergistic effect was found between MW and UV light. The removal rate with the MW/UV process was much faster than that with UV light irradiation only. Degradation of NOR followed second-order kinetics and ~72% of NOR could be removed in the first 5 min of MW/UV reaction. Influence of inorganic ions (cations (K+, Mg2+, Ca2+, Cu2+ and anions (Cl−, SO42−, NO3−, CO32−, humic acid (HA and surfactants (cation, anion, and non-ionic on the degradation of NOR by the MW/UV process was investigated. Among the ions, Cu2+ and NO3− ions inhibited the degradation of NOR. The presence of HA and surfactants in water showed a slight inhibition on the NOR removal. Furthermore, the NOR degradation in the MW/UV process was primarily caused by the ·OH-photosensitization steps. Seven intermediates formed by the oxidation of NOR were identified and three reaction pathways were proposed. Removals of NOR in tap water (TW, synthetic wastewater (WW, river water (RW, and seawater (SW were also studied, which demonstrated that the MW/UV process was an effective oxidation technology for degrading fluoroquinolone antibiotics in different water matrices.

  8. Evaluation of the interactions between chitosan and humics in media for the controlled release of nitrogen fertilizer.

    Science.gov (United States)

    Araújo, Bruno R; Romão, Luciane P C; Doumer, Marta E; Mangrich, Antonio S

    2017-04-01

    The aim of this study was to evaluate the interactions of peat, humic acids, and humin with urea dispersed in chitosan, in systems intended for the controlled release of urea. Spheres of chitosan with humic material and urea intentionally added to the media were prepared and characterized by means of elemental analysis (CHN), electron paramagnetic resonance (EPR), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). The spheres possessed functional groups related to humic substances that interacted with the chitosan, and the presence of urea in the media was also confirmed after it has been added. Release experiments demonstrated that the samples released urea in a controlled manner that was dependent on pH, increasing in the order: pH 2.5 humin-urea (CHMU) obtained in the first day of the experiment. The release of urea did not exceed 70% after 7 days. The results demonstrated the potential of using peat, humic acids, and humin, in combination with chitosan, in order to manufacture controlled release urea fertilizers and contribute to reducing adverse environmental and economic impacts. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Humus accumulation, humification, and humic acid composition in soils of two post-mining chronosequences after coal mining

    Czech Academy of Sciences Publication Activity Database

    Abakumov, E.V.; Cajthaml, Tomáš; Brus, Jiří; Frouz, J.

    2013-01-01

    Roč. 13, č. 3 (2013), s. 491-500 ISSN 1439-0108 R&D Projects: GA MŠk 2B08023; GA MŠk LC06066 Institutional support: RVO:61388971 ; RVO:61389013 Keywords : Humus accumulation * Humic acids composition * Humification Subject RIV: EE - Microbiology, Virology; CD - Macromolecular Chemistry (UMCH-V) Impact factor: 2.107, year: 2013

  10. Time-dependent uptake and toxicity of nickel to Enchytraeus crypticus in the presence of humic acid and fulvic acid

    NARCIS (Netherlands)

    He, Erkai; Qiu, Hao; Qiu, Rongliang; Rentenaar, Charlotte; Devresse, Quentin; Van Gestel, Cornelis A.M.

    2017-01-01

    The present study aimed to investigate the influence of different fractions of dissolved organic carbon (DOC) on the uptake and toxicity of nickel (Ni) in the soil invertebrate Enchytraeus crypticus after different exposure times. The addition of DOC as humic acid or fulvic acid significantly

  11. Distinct Effects of Humic Acid on Transport and Retention of TiO2 Rutile Nanoparticles in Saturated Sand Columns

    Science.gov (United States)

    The distinct effects of humic acid (HA, 0−10 mg L−1) on the transport of titanium dioxide (rutile) nanoparticles (nTiO2) through saturated sand columns were observed under conditions of environmental relevance (ionic strength 3−200 mM NaCl, pH 5.7 and 9.0). Specifically, the tra...

  12. Distinct Effects of Humic Acid on Transport and Retention of TiO2 Rutile Nanoparticles in Saturated Sand Column

    Science.gov (United States)

    Distinct effects of humic acid (HA, 0 – 10 mg L-1) on the transport of titanium dioxide (rutile) nanoparticles (nTiO2) through saturated sand columns were observed under conditions of environmental relevance (ionic strength 3 – 200 mM NaCl, pH 5.7 and 9.0). Specifical...

  13. An investigation of inorganic antimony species and antimony associated with soil humic acid molar mass fractions in contaminated soils

    International Nuclear Information System (INIS)

    Steely, Sarah; Amarasiriwardena, Dulasiri; Xing Baoshan

    2007-01-01

    The presence of antimony compounds is often suspected in the soil of apple orchards contaminated with lead arsenate pesticide and in the soil of shooting ranges. Nitric acid (1 M) extractable Sb from the shooting range (8300 μg kg -1 ) and the apple orchard (69 μg kg -1 ) had considerably higher surface Sb levels than the control site ( -1 ), and Sb was confined to the top ∼30 cm soil layer. Sb(V) was the principal species in the shooting range and the apple orchard surface soils. Size exclusion chromatography-inductively coupled plasma-mass spectrometry (SEC-ICP-MS) analysis of humic acids isolated from the two contaminated soils demonstrated that Sb has complexed to humic acid molar mass fractions. The results also indicate that humic acids have the ability to arrest the mobility of Sb through soils and would be beneficial in converting Sb(III) to a less toxic species, Sb(V), in contaminated areas. - The soil surface and depth distribution Sb(V) and Sb(III) species in a contaminated apple orchard and a shooting range, and the effect soil humic acids on inorganic antimony species is reported

  14. The influence of agitation on aggregates formed during treatment of water with a content of humic substances

    Czech Academy of Sciences Publication Activity Database

    Pivokonská, Lenka; Pivokonský, Martin

    2006-01-01

    Roč. 6, č. 1 (2006), s. 211-218 ISSN 1606-9749 R&D Projects: GA AV ČR KJB200600501 Institutional research plan: CEZ:AV0Z20600510 Keywords : Aggregation * humic substances * particle size distribution Subject RIV: BK - Fluid Dynamics

  15. 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

  16. 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

  17. 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.

  18. Effects of kaolinite and drying temperature on the persistence of soil water repellency induced by humic acids

    NARCIS (Netherlands)

    Lichner, L.; Babejová, N.; Dekker, L.W.

    2002-01-01

    The effects of kaolinite additions and drying temperature on the persistence of soil water repellency, induced by humic acids from peat, were assessed in this study. It was found that additions of 5 and 10% kaolinite (referred to as the most effective material in combating the water repellency) did

  19. 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.)

  20. 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.

  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. The influence of lake water alkalinity and humic substances on particle dispersion and lanthanum desorption from a lanthanum modified bentonite

    DEFF Research Database (Denmark)

    Reitzel, Kasper; Balslev, Kristiane Astrid; Jensen, Henning S

    2017-01-01

    A 12 days laboratory study on potential desorption of Lanthanum (La) from a commercial La modified clay (Phoslock) was conducted using lake water from 17 Danish lakes with alkalinities between 0.02 and 3.7 meq L-1and varying concentrations of DOC and humic acids (HA's). A similar study was conduc...

  3. Intraparticulate Metal Speciation Analysis of Soft Complexing Nanoparticles. The Intrinsic Chemical Heterogeneity of Metal-Humic Acid Complexes

    DEFF Research Database (Denmark)

    Town, R. M.; van Leeuwen, Herman P.

    2016-01-01

    The counterion condensation-Dorman (CCD) model for the electrostatic features of soft, charged nanopartides (NPs) is applied to the determination of the intrinsic stability constants, kit, for inner-sphere Cd(II) and Cu(II) complexes with humic acid NPs. The novel CCD model accounts for the stron...

  4. 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...

  5. Genome sequence of the button mushroom Agaricus bisporus reveals mechanisms governing adaptation to a humic-rich ecological niche

    Science.gov (United States)

    Emmanuelle Morin; Annegret Kohler; Adam R. Baker; Marie Foulongne-Oriol; Vincent Lombard; Laszlo G. Nagy; Robin A. Ohm; Aleksandrina Patyshakuliyeva; Annick Brun; Andrea L. Aerts; Andrew M. Bailey; Christophe Billette; Pedro M. Coutinho; Greg Deakin; Harshavardhan Doddapaneni; Dimitrios Floudas; Jane Grimwood; Kristiina Hild& #233; n; Ursula K& #252; es; Kurt M. LaButti; Alla Lapidus; Erika A. Lindquist; Susan M. Lucas; Claude Murat; Robert W. Riley; Asaf A. Salamov; Jeremy Schmutz; Venkataramanan Subrananian; Han A.B. W& #246; sten; Jianping Xu; Daniel C. Eastwood; Gary D. Foster; Anton S.M. Sonnenberg; Daniel Cullen; Ronald P. de Vries; Taina Lundell; David S. Hibbett; Bernard Henrissat; Kerry S. Burton; Richard W. Kerrigan; Michael P. Challen; Igor V. Grigoriev; Francis. Martin

    2012-01-01

    Agaricus bisporus is the model fungus for the adaptation, persistence,and growth in the humic-rich leaf-litter environment. Aside from its ecological role, A. bisporus has been an important component of the human diet for over 200 y and worldwide cultivation of the "button mushroom" forms a multibillion dollar...

  6. Study the properties of activated carbon and oxyhydroxide aluminum as sorbents for removal humic substances from natural waters

    International Nuclear Information System (INIS)

    Shiyan, L N; Machekhina, K I; Gryaznova, E N

    2016-01-01

    The present work relates to the problem of high-quality drinking water supply using processes of adsorption on activated carbon and aluminum oxyhydroxide for removal humic- type organic substances. Also the paper reports on sorbtion properties of the activeted carbon Norit SA UF and oxyhydroxide aluminum for removal humic substances. It was found out that the maximum adsorption capacity of activated carbon to organic substances is equal to 0.25 mg/mg and aluminum oxyhydroxide is equal to 0.3 mg/mg. It is shown that the maximum adsorption capacity of activated carbon Norit SA UF to iron (III) ions is equal to 0.0045 mg/mg and to silicon ions is equal to 0.024 mg/mg. Consequently, the aluminum oxyhydroxide has better adsorption characteristics in comparison with the activated carbon for removal of humic substances, iron and silicon ions. It is associated with the fact that activated carbon has a large adsorption surface, and this is due to its porous structure, but not all molecules can enter into these pores. Therefore, the fibrous structure of aluminum oxyhydroxide promotes better sorption capacity. The presented results suggest that activated carbon Norit SA UF and aluminum oxyhydroxide can be used as sorbents for removal humic substances or other organic substances from groundwater and natural waters. (paper)

  7. Analytical pyrolysis and thermally assisted hydrolysis and methylation of EUROSOIL humic acid samples: a key to their source

    NARCIS (Netherlands)

    Buurman, P.; Nierop, K.G.J.; Kaal, J.; Senesi, S.I.

    2009-01-01

    Humic acids have been widely investigated by spectroscopic methods, especially NMR and FTIR, and they are known to show significant differences according to their origin. Low resolution methods such as NMR and FTIR, however cannot easily distinguish different input sources or establish relations

  8. 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.

  9. Interaction between lysozyme and humic acid in layer-by-layer assemblies: Effects of pH and ionic strength

    NARCIS (Netherlands)

    Tan, W.F.; Norde, W.; Koopal, L.K.

    2014-01-01

    The interaction between protein and soluble organic matter is studied through layer-by-layer assembly of lysozyme (LSZ) and purified Aldrich humic acid (PAHA) at a solid surface (2-D) and in solution (3-D). By bringing a silica surface in alternating contact with solutions of LSZ and PAHA a

  10. Interaction between lysozyme and humic acid in layer-by-layer assemblies : Effects of pH and ionic strength

    NARCIS (Netherlands)

    Tan, Wenfeng; Norde, Willem; Koopal, Luuk K.

    2014-01-01

    The interaction between protein and soluble organic matter is studied through layer-by-layer assembly of lysozyme (LSZ) and purified Aldrich humic acid (PAHA) at a solid surface (2-D) and in solution (3-D). By bringing a silica surface in alternating contact with solutions of LSZ and PAHA a

  11. 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…

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

    International Nuclear Information System (INIS)

    Luste, S.; Maekelae, J.; Manninen, P.

    2012-06-01

    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 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.)

  13. Syntrophy in Methanogenic Degradation

    NARCIS (Netherlands)

    Worm, P.; Müller, N.; Plugge, C.M.; Stams, A.J.M.; Schink, B.

    2010-01-01

    This chapter deals with microbial communities of bacteria and archaea that closely cooperate in methanogenic degradation and perform metabolic functions in this community that neither one of them could carry out alone. The methanogenic degradation of fatty acids, alcohols, most aromatic compounds,

  14. Degradations and Rearrangement Reactions

    Science.gov (United States)

    Zhang, Jianbo

    This section deals with recent reports concerning degradation and rearrangement reactions of free sugars as well as some glycosides. The transformations are classified in chemical and enzymatic ways. In addition, the Maillard reaction will be discussed as an example of degradation and rearrangement transformation and its application in current research in the fields of chemistry and biology.

  15. Investigations of the uptake of transuranic radionuclides by humic and fulvic acids chemically immobilized on silica gel and their competitive release by complexing agents

    International Nuclear Information System (INIS)

    Bulman, R.A.; Szabo, G.; Clayton, R.F.; Clayton, C.R.

    1998-01-01

    The chemistry of the interactions of transuranic elements (TUs) with humic substances needs to be understood so that humate-mediated movement of transuranic radionuclides through the environment can be predicted. This paper reports the chemical immobilization on silica gel of humic and fulvic acids and evaluates the potential of these new materials for the retention of Pu and Am. In addition to the preparation of the foregoing immobilized humic substances, other low molecular weight metal-binding ligands have also been immobilized on silica gel to investigate the binding sites for transuranic elements (TUs) in humic substances. The X-ray photoelectron spectra (XPS) of Th(IV) complexed by humic acid and the immobilized humic acid are similar thus it appears that immobilization of humic acid does not generate any configurational changes in the Th(IV)-binding sites of the macromolecule. A variety of chelating agents partly mobilize these TUs sorbed on the solid phases. A batch method was used to determine the distribution coefficients (R d ) of Pu and Am between the silica gels and aqueous solutions of phosphate and citrate. The effects of the immobilized ligands, the anions and pH in the solution on sorption were assessed. Distributed coefficients (R d ) for the uptake of Pu and Am by these prepared solid phases are, in some cases, of a similar order of magnitude as those determined for soil and particles suspended in terrestrial surface waters

  16. Decomposing leaf litter: the effect of allochthonous degradation products on the antioxidant fitness and photosynthesis of Vesicularia dubyana.

    Science.gov (United States)

    Nimptsch, Jorge; Pflugmacher, Stephan

    2008-03-01

    Leaf litter is one of the major input sources of organic carbon and nutrients in freshwater ecosystems. Throughout the degradation and leaching of leaf litter in freshwater bodies, "new born" substances are continuously generated and may aggregate to form humic substances (HS). Although the effect of HS on the stress physiology of aquatic macrophytes has been case of several investigations, the effect of these "new born" compounds (leaf litter breakdown products) on the stress physiology of aquatic plants has not been studied yet. Our results show that leaf litter degradation extracts (LLDEs) from oak, beech, and mixed oak and beech leaves have deleterious effects on the physiology of the aquatic bryophyte Vesicularia dubyana, decreasing photosynthetic activity and enhancing oxidative stress response. These findings suggest that leaf litter degradation extracts may be an important environmental factor influencing community structure within freshwater ecosystems.

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

    Directory of Open Access Journals (Sweden)

    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.

  18. Removal of Humic Substances from Water by Advanced Oxidation Process Using UV/TiO2 Photo Catalytic Technology

    Directory of Open Access Journals (Sweden)

    Hassan Khorsandi

    2009-01-01

    Full Text Available Humic substances have been known as precursors to disinfection by-products. Because conventional treatment processes cannot meet disinfection by-product standards, novel methods have been increasingly applied for the removal of disinfection by-products precursors. The UV/TiO2 process is one of the advanced oxidation processes using the photocatalytic technology. The most important advantages of this process are its stability and high efficiency removal. The present study aims to investigate the effect of UV/TiO2 photo-catalytic technology on removal of humic substances. The study was conducted in a lab-scale batch photo-catalytic reactor using the interval experimental method. The UV irradiation source was a low pressure mercury vapor lamp 55w that was axially centered and was immersed in a humic acids solution within a stainless steel tubular 2.8 L reaction volume. Each of the samples taken from the UV/TiO2 process and other processes studied were analyzed for their dissolved organic carbon, UV absorbance at 254nm, and specific UV254 absorbance. The results indicated the high efficiency of the UV/TiO2 photo-catalytic process (TiO2=0.1 g/L and pH=5, compared to other processes, for humic substances removal from water sources. The process was also found to be capable of decreasing the initial dissolved organic carbon from 5 to 0.394 mg/L. The Specific UV254 Absorbance of 2.79 L/mg.m was attained after 1.5 hr. under photo-catalytic first order reaction (k= 0.0267 min-1. It may be concluded that the UV/TiO2 process can provide desirable drinking water quality in terms of humic substance content.

  19. Effects of a sedimentary humic acid on plant growth: study of the general mechanisms of action upon root application in cucumber plants (Cucumis Sativus l. Cv Ashley).

    OpenAIRE

    Olaetxea-Indaburu, M. (Maite); Baigorri-Ekisoáin, R. (Roberto); Garcia-Mina, J.M. (José María)

    2015-01-01

    HS (humic substances) constitute one of the most abundant forms of organic matter in the biosphere. Many studies reported the ability of humic acids (HAs) isolated from HS to affect plant the plant development of diverse plant species. However, the mechanism of action that is behind these events is scarcely understood and it is not integrated into a holistic view. To this end, the aim of this work was to study the mechanism of action of an specific sedimentary humic acid (SHA) under roots ...

  20. [The examination of content and structure of humic compounds in Miocene water, therapeutic peats and lignite on the basis of differential absorbing spectra].

    Science.gov (United States)

    Drobnik, Michał; Latour, Teresa

    2010-01-01

    In the examination the differential absorbing spectra of humic compounds present in underground Miocene waters were compared with the spectra originated from therapeutic peat and lignite. From the samples of examined material trough selective extraction were separated humic acids, hymatomelanic acids and fulvonic acids. The spectrograms in the range UV-VIS of those compounds were made. The results of the fourth degree differential were spectra were with well separated peaks for specified wave-length. In spectra obtained from Miocene water and peats were found peaks characteristic for specific frequently common electromagnetic radiation wave-length. In spectra obtained from lignite there were not found peaks characteristic for humic acids.

  1. An efficient approach to the quantitative analysis of humic acid in water.

    Science.gov (United States)

    Wang, Xue; Li, Bao Qiong; Zhai, Hong Lin; Xiong, Meng Yi; Liu, Ying

    2016-01-01

    Rayleigh and Raman scatterings inevitably appear in fluorescence measurements, which make the quantitative analysis more difficult, especially in the overlap of target signals and scattering signals. Based on the grayscale images of three-dimensional fluorescence spectra, the linear model with two selected Zernike moments was established for the determination of humic acid, and applied to the quantitative analysis of the real sample taken from the Yellow River. The correlation coefficient (R(2)) and leave-one-out cross validation correlation coefficient (R(2)cv) were up to 0.9994 and 0.9987, respectively. The average recoveries were reached 96.28%. Compared with N-way partial least square and alternating trilinear decomposition methods, our approach was immune from the scattering and noise signals owing to its powerful multi-resolution characteristic and the obtained results were more reliable and accurate, which could be applied in food analyses. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Combining electrophoresis with detection under ultraviolet light and multiple ultrafiltration for isolation of humic fluorescence fractions.

    Science.gov (United States)

    Trubetskaya, Olga E; Shaloiko, Lubov A; Demin, Dmitrii V; Marchenkov, Victor V; Proskuryakov, Ivan I; Coelho, Christian; Trubetskoj, Oleg A

    2011-04-01

    Polyacrylamide gel electrophoresis of chernozem soil humic acids (HAs) followed by observation under UV (312 nm) excitation light reveals new low molecular weight (MW) fluorescent fractions. Ultrafiltration of HAs sample in 7 M urea on a membrane of low nominal MW retention (NMWR, 5 kDa) was repetitively used for separation of fluorescent and non-fluorescent species. Thirty ultrafiltrates and the final retentate R were obtained. Fluorescence maxima of separate ultrafiltrates were different and non-monotonously changed in the range of 475-505 nm. Fluorescence maxima of less than 490 nm were detected only in the four first utrafiltrates. For further physical-chemical analyses all utrafiltrates were combined into a fraction called UFchernozem soil HAs complex. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Characterization of Humic Acid Modified Bentonite Binder for Iron Ore Pelletization

    Science.gov (United States)

    Sun, Yang; Xu, Bin; Zhang, Yuanbo; Liu, Bingbing; Zhou, Youlian; Su, Zijian

    Anew kind of iron ore pellet binder named humic acid modifying bentonite (HA-MB) has been developed by the author's group, which has the advantages of both organic HA and inorganic bentonite. The green pellet strength can be obviously improved by using the HA-MB binder. In this study, the detection of the characterization of HA-MB was conducted by zeta-potential, TG-DSC, FTIR, XRD, etc. The addition of HA was able to change the zeta-potential of bentonite. And HA-MB had more weight loss than that of bentonite according to TG-DSC analysis. Some functional groups of HA were also found in the FTIR spectrum of HA-MB. XRD result indicated that d(001) of crystal layer of bentonite had apparently altered due to the addition of HA.

  4. Effect of humic acids on the growth and the biochemical composition of Arthrospira platensis

    Directory of Open Access Journals (Sweden)

    Massiel Vanessa Rivera Gonzalez

    2017-01-01

    Full Text Available The purpose of this research was to evaluate the effect of three concentrations of humic acids (HA 1, 10, 100 mg/L against a concentration of indole acetic acid (IAA on production of biomass, pigments, proteins, carbohydrates and lipids of A. platensis.  Cultures discontinuous in Zarrouk 25% medium supplemented with HA and IAA under conditions of aeration constant and photoperiod from 12:12 hours, during 30 days were made. It was found that the maximum biomass production was higher in the culture supplemented with 10 mg / L of AH, compared to the control and cultures supplemented with AIA. In the same way the highest production of pigments, proteins and carbohydrates were observed in this treatment. Therefore, the growth and production of metabolites of A. platensis was increased, which makes it possible to observe the potential use of these substances as organic biological stimulants.

  5. Isotope exchange study of the dissociation of metal-humic substance complexes

    International Nuclear Information System (INIS)

    Mizera, J.; Jansova, A.; Hvozdova, I.; Benes, P.; Novak, F.

    2003-01-01

    Isotope exchange was employed to study dissociation of metal cations from their complexes with humic substances (HS). Dissociation of cation from HS controls the rate of isotope exchange between two identical metal-HS solutions (but for the presence of a radiotracer) divided by a dialysis membrane. The rate of isotope exchange of Eu/ 152 Eu and Co/ 60 Co in the systems with various HS was monitored as a function of pH, ionic strength, and the degree of HS loading with metal. The apparent rate of Eu-HS dissociation was found to be enhanced by decreasing pH, increasing ionic strength, and increasing metal loading. Co-HS dissociation was too fast to be followed by the method. For interpretation of the experimental kinetic data, the multiple first order law has been applied. Based on the results, a concept of HS as a mixture of two types of binding sites is discussed. (author)

  6. Effect of humic substance photodegradation on bacterial growth and respiration in lake water

    Science.gov (United States)

    Anesio, A.M.; Graneli, W.; Aiken, G.R.; Kieber, D.J.; Mopper, K.

    2005-01-01

    This study addresses how humic substance (HS) chemical composition and photoreactivity affect bacterial growth, respiration, and growth efficiency (BGE) in lake water. Aqueous solutions of HSs from diverse aquatic environments representing different dissolved organic matter sources (autochthonous and allochthonous) were exposed to artificial solar UV radiation. These solutions were added to lake water passed through a 0.7-??m-pore-size filter (containing grazer-free lake bacteria) followed by dark incubation for 5, 43, and 65 h. For the 5-h incubation, several irradiated HSs inhibited bacterial carbon production (BCP) and this inhibition was highly correlated with H 2O2 photoproduction. The H2O2 decayed in the dark, and after 43 h, nearly all irradiated HSs enhanced BCP (average 39% increase relative to nonirradiated controls, standard error = 7.5%, n = 16). UV exposure of HSs also increased bacterial respiration (by ???18%, standard error = 5%, n = 4), but less than BCP, resulting in an average increase in BGE of 32% (standard error = 10%, n = 4). Photoenhancement of BCP did not correlate to HS bulk properties (i.e., elemental and chemical composition). However, when the photoenhancement of BCP was normalized to absorbance, several trends with HS origin and extraction method emerged. Absorbance-normalized hydrophilic acid and humic acid samples showed greater enhancement of BCP than hydrophobic acid and fulvic acid samples. Furthermore, absorbance-normalized autochthonous samples showed ???10-fold greater enhancement of BCP than allochthonous-dominated samples, indicating that the former are more efficient photoproducers of biological substrates. Copyright ?? 2005, American Society for Microbiology. All Rights Reserved.

  7. Effects of humic acid on the interactions between zinc oxide nanoparticles and bacterial biofilms

    Energy Technology Data Exchange (ETDEWEB)

    Ouyang, Kai; Yu, Xiao-Ying; Zhu, Yunlin; Gao, Chunhui; Huang, Qiaoyun; Cai, Peng

    2017-12-01

    The effects of humic acid (HA) on interactions between ZnO nanoparticles (ZnO NPs) and Pseudomonas putida KT2440 biofilms at different maturity stages were investigated. Three stages of biofilm development were identified according to bacterial adenosine triphosphate (ATP) activity associated with biofilm development process. In the initial biofilm stage 1, the ATP content of bacteria was reduced by more than 90% when biofilms were exposed to ZnO NPs. However, in the mature biofilm stages 2 and 3, the ATP content was only slightly decreased. Biofilms at stage 3 exhibited less susceptibility to ZnO NPs than biofilms at stage 2. These results suggest that more mature biofilms have a significantly higher tolerance to ZnO NPs compared to young biofilms. In addition, biofilms with intact extracellular poly-meric substances (EPS) showed higher tolerance to ZnO NPs than those without EPS, indicating that EPS play a key role in alleviating the toxic effects of ZnO NPs. In both pure ZnO NPs and ZnO-HA mixtures, dissolved Zn2+ originating from the NPs significantly contributed to the overall toxicity. The presence of HA dramatically decreased the toxicity of ZnO NPs due to the binding of Zn2+ on HA. The combined results from this work suggest that the biofilm maturity stages and environmental constituents (such as humic acid) are important factors to consider when evaluating potential risks of NPs to ecological systems.

  8. Investigating organic molecules responsible of auxin-like activity of humic acid fraction extracted from vermicompost

    International Nuclear Information System (INIS)

    Scaglia, Barbara; Nunes, Ramom Rachide; Rezende, Maria Olímpia Oliveira; Tambone, Fulvia; Adani, Fabrizio

    2016-01-01

    This work studied the auxin-like activity of humic acids (HA) obtained from vermicomposts produced using leather wastes plus cattle dung at different maturation stages (fresh, stable and mature). Bioassays were performed by testing HA concentrations in the range of 100–6000 mg carbon L −1 . 13 C CPMAS-NMR and GC–MS instrumental methods were used to assess the effect of biological processes and starting organic mixtures on HA composition. Not all HAs showed IAA-like activity and in general, IAA-like activity increased with the length of the vermicomposting process. The presence of leather wastes was not necessary to produce the auxin-like activity of HA, since HA extracted from a mix of cattle manure and sawdust, where no leather waste was added, showed IAA-like activity as well. CPMAS 13 CNMR revealed that HAs were similar independently of the mix used and that the humification process involved the increasing concentration of pre-existing alkali soluble fractions in the biomass. GC/MS allowed the identification of the molecules involved in IAA-like effects: carboxylic acids and amino acids. The concentration of active molecules, rather than their simple presence in HA, determined the bio-stimulating effect, and a good linear regression between auxin-like activity and active stimulating molecules concentration was found (R 2 = − 0.85; p < 0.01, n = 6). - Highlights: • Vermicomposting converts waste into organic fertilizer. • Vermicomposts can have biostimulating effect for the presence of hormone-like molecules. • Auxine-like activity was associated to the vermicompost humic acid fraction (HA). • HA carboxylic acids and amino acids, were reported to act as auxin-like molecules. • A linear regression was found between molecules and auxin-like activity.

  9. Effective removal of phosphate from aqueous solution using humic acid coated magnetite nanoparticles.

    Science.gov (United States)

    Rashid, Mamun; Price, Nathaniel T; Gracia Pinilla, Miguel Ángel; O'Shea, Kevin E

    2017-10-15

    Effective removal of excess phosphate from water is critical to counteract eutrophication and restore water quality. In this study, low cost, environmentally friendly humic acid coated magnetite nanoparticles (HA-MNP) were synthesized and applied for the remediation of phosphate from aqueous media. The HA-MNPs, characterized by FTIR, TEM and HAADF-STEM showed the extensive coating of humic acid on the magnetite surface. The magnetic nanoparticles with diameters of 7-12 nm could be easily separated from the reaction mixture by using a simple hand held magnet. Adsorption studies demonstrate the fast and effective separation of phosphate with maximum adsorption capacity of 28.9 mg/g at pH 6.6. The adsorption behavior follows the Freundlich isotherm suggesting the formation of non-uniform multilayers of phosphate on the heterogeneous surface of HA-MNP. The adsorption kinetic fits the pseudo-second order model well with rate constants of 0.206 ± 0.003, 0.073 ± 0.002 and 0.061 ± 0.003 g mg -1 min -1 for phosphate (P) concentrations of 2, 5 and 10 mg/L respectively. The removal of phosphate was found higher at acidic and neutral pH compared to basic conditions. The nanoparticles exhibit good selectivity and adsorption efficiency for phosphate in presence of co-existing ions such as Cl - , SO 4 2- and NO 3 - with some inhibition effect by CO 3 2- . The effect of temperature on the adsorption reveals that the process is endothermic and spontaneous. HA-MNPs are promising, simple, environmentally friendly materials for the removal of phosphate from aqueous media. Copyright © 2017. Published by Elsevier Ltd.

  10. Complexes of the antimicrobial ciprofloxacin with soil, peat, and aquatic humic substances.

    Science.gov (United States)

    Aristilde, Ludmilla; Sposito, Garrison

    2013-07-01

    Natural organic matter (NOM) is implicated in the binding of antibiotics by particles in soils and waters. The authors' previous computational study revealed structural rearrangement of both hydrophilic and hydrophobic moieties of NOM to favor H-bonding and other intermolecular interactions, as well as both competition with ion-exchange reactions and bridging interactions by NOM-bound divalent cations. The importance of these interactions was investigated using fluorescence-quenching spectroscopy to study the adsorption of ciprofloxacin (Cipro), a fluoroquinolone antibiotic, on 4 reference humic substances (HSs): Elliott soil humic acid (HA), Pahokee peat HA, and Suwannee river HA and fulvic acid. A simple affinity spectrum HS model was developed to characterize the cation-exchange capacity and the amount of H-bond donor moieties as a function of pH. The adsorption results stress the influence of both pH conditions and the type of HS: both soil HA and peat HA exhibited up to 3 times higher sorption capacity than the aquatic HS at pH ≥ 6, normalizing to the aromatic C content accounted for the differences among the terrestrial HS, and increasing the concentration of divalent cations led to a decrease in adsorption on aquatic HA but not on soil HA. In addition, the pH-dependent speciation models of the Cipro-HS complexes illustrate an increase in complexation due to an increase in deprotonation of HS ligands with increasing pH and, at circumneutral and alkaline pH, enhanced complexation of zwitterionic Cipro only in the presence of soil HA and peat HA. The findings of the present study imply that, in addition to electrostatic interactions, van der Waals interactions as facilitated by aromatic structures and H-bond donating moieties in terrestrial HS may facilitate a favorable binding environment. Environ Toxicol Chem 2013;32:1467-1478. © 2013 SETAC. Copyright © 2013 SETAC.

  11. Aminopropyl-Silica Hybrid Particles as Supports for Humic Acids Immobilization

    Directory of Open Access Journals (Sweden)

    Mónika Sándor

    2016-01-01

    Full Text Available A series of aminopropyl-functionalized silica nanoparticles were prepared through a basic two step sol-gel process in water. Prior to being aminopropyl-functionalized, silica particles with an average diameter of 549 nm were prepared from tetraethyl orthosilicate (TEOS, using a Stöber method. In a second step, aminopropyl-silica particles were prepared by silanization with 3-aminopropyltriethoxysilane (APTES, added drop by drop to the sol-gel mixture. The synthesized amino-functionalized silica particles are intended to be used as supports for immobilization of humic acids (HA, through electrostatic bonds. Furthermore, by inserting beside APTES, unhydrolysable mono-, di- or trifunctional alkylsilanes (methyltriethoxy silane (MeTES, trimethylethoxysilane (Me3ES, diethoxydimethylsilane (Me2DES and 1,2-bis(triethoxysilylethane (BETES onto silica particles surface, the spacing of the free amino groups was intended in order to facilitate their interaction with HA large molecules. Two sorts of HA were used for evaluating the immobilization capacity of the novel aminosilane supports. The results proved the efficient functionalization of silica nanoparticles with amino groups and showed that the immobilization of the two tested types of humic acid substances was well achieved for all the TEOS/APTES = 20/1 (molar ratio silica hybrids having or not having the amino functions spaced by alkyl groups. It was shown that the density of aminopropyl functions is low enough at this low APTES fraction and do not require a further spacing by alkyl groups. Moreover, all the hybrids having negative zeta potential values exhibited low interaction with HA molecules.

  12. Soil remediation: humic acids as natural surfactants in the washings of highly contaminated soils

    International Nuclear Information System (INIS)

    Conte, Pellegrino; Agretto, Anna; Spaccini, Riccardo; Piccolo, Alessandro

    2005-01-01

    The remediation of the highly contaminated site around the former chemical plant of ACNA (near Savona) in Northern Italy is a top priority in Italy. The aim of the present work was to contribute in finding innovative and environmental-friendly technology to remediate soils from the ACNA contaminated site. Two soils sampled from the ACNA site (A and B), differing in texture and amount and type of organic contaminants, were subjected to soil washings by comparing the removal efficiency of water, two synthetic surfactants, sodium dodecylsulphate (SDS) and Triton X-100 (TX100), and a solution of a natural surfactant, a humic acid (HA) at its critical micelle concentration (CMC). The extraction of pollutants by sonication and soxhlet was conducted before and after the soil washings. Soil A was richer in polycyclic aromatic hydrocarbons, whereas soil B had a larger content of thiophenes. Sonication resulted more analytically efficient in the fine-textured soil B. The coarse-textured soil A was extracted with a general equal efficiency also by soxhlet. Clean-up by water was unable to exhaustively remove contaminants from the two soils, whereas all the organic surfactants revealed very similar efficiencies (up to 90%) in the removal of the contaminants from the soils. Hence, the use of solutions of natural HAs appears as a better choice for soil washings of highly polluted soils due to their additional capacity to promote microbial activity, in contrast to synthetic surfactants, for a further natural attenuation in washed soils. - Solutions of natural humic acids appear to be a better choice for washing highly polluted soils

  13. Enhanced transport of ferrihydrite colloid by chain-shaped humic acid colloid in saturated porous media.

    Science.gov (United States)

    Ma, Jie; Guo, Huaming; Lei, Mei; Li, Yongtao; Weng, Liping; Chen, Yali; Ma, Yuling; Deng, Yingxuan; Feng, Xiaojuan; Xiu, Wei

    2018-04-15

    Both humic acid and colloid particle size effectively regulate colloid transport. However, little is known about effect of particle size and configuration of humic acid colloid (HA colloid ) on enhanced-transport of ferrihydrite colloid (FH colloid ) in porous media. Co-transport of HA colloid and FH colloid at different pH was systematically investigated by monitoring breakthrough curves (BTCs) in saturated sand columns. The colloid transport model and the (X)DLVO theory were used to reveal the mechanism of HA colloid -enhanced FH colloid transport in the columns. Results showed that HA colloid enhanced FH colloid transport in neutral and alkaline conditions. In neutral conditions, small HA colloid (F-HA colloid ) with chain-shaped structure enhanced FH colloid transport more prominently than pristine granular HA colloid . The chain-shaped F-HA colloid caused osmotic repulsion and elastic-steric repulsion between colloids and sand, leading to enhanced transport. However, the granular HA colloid readily occurred as deposition due to attachment and straining, which decreased the enhanced transport of FH colloid . In alkaline conditions, both HA colloid and F-HA colloid were chain-shaped, with longer chains of HA colloid than F-HA colloid . Ferrihydrite colloid transport was enhanced by HA colloid more significantly than F-HA colloid due to stronger repulsion between mixed HA colloid -FH colloid and sand. It suggested that regulation of particle size and morphology of HA colloid would enhance FH colloid transport and further help in understanding FH colloid -facilitated contaminants transport in porous media. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Investigating organic molecules responsible of auxin-like activity of humic acid fraction extracted from vermicompost

    Energy Technology Data Exchange (ETDEWEB)

    Scaglia, Barbara, E-mail: barbara.scaglia@unimi.it [Gruppo Ricicla Labs – DiSAA, Università degli Studi di Milano, Via Celoria 2 (Italy); Nunes, Ramom Rachide; Rezende, Maria Olímpia Oliveira [Laboratório de Química Ambiental, Universidade de São Paulo, Instituto de Química de São Carlos, Avenida Trabalhador São Carlense, 400, São Carlos (Brazil); Tambone, Fulvia [Gruppo Ricicla Labs – DiSAA, Università degli Studi di Milano, Via Celoria 2 (Italy); Adani, Fabrizio, E-mail: fabrizio.adani@unimi.it [Gruppo Ricicla Labs – DiSAA, Università degli Studi di Milano, Via Celoria 2 (Italy)

    2016-08-15

    This work studied the auxin-like activity of humic acids (HA) obtained from vermicomposts produced using leather wastes plus cattle dung at different maturation stages (fresh, stable and mature). Bioassays were performed by testing HA concentrations in the range of 100–6000 mg carbon L{sup −1}. {sup 13}C CPMAS-NMR and GC–MS instrumental methods were used to assess the effect of biological processes and starting organic mixtures on HA composition. Not all HAs showed IAA-like activity and in general, IAA-like activity increased with the length of the vermicomposting process. The presence of leather wastes was not necessary to produce the auxin-like activity of HA, since HA extracted from a mix of cattle manure and sawdust, where no leather waste was added, showed IAA-like activity as well. CPMAS {sup 13}CNMR revealed that HAs were similar independently of the mix used and that the humification process involved the increasing concentration of pre-existing alkali soluble fractions in the biomass. GC/MS allowed the identification of the molecules involved in IAA-like effects: carboxylic acids and amino acids. The concentration of active molecules, rather than their simple presence in HA, determined the bio-stimulating effect, and a good linear regression between auxin-like activity and active stimulating molecules concentration was found (R{sup 2} = − 0.85; p < 0.01, n = 6). - Highlights: • Vermicomposting converts waste into organic fertilizer. • Vermicomposts can have biostimulating effect for the presence of hormone-like molecules. • Auxine-like activity was associated to the vermicompost humic acid fraction (HA). • HA carboxylic acids and amino acids, were reported to act as auxin-like molecules. • A linear regression was found between molecules and auxin-like activity.

  15. Spin Labeling ESR Investigation of a Role of Humic Acids at Covalent Binding of Xenobiotics to Soil

    Science.gov (United States)

    Aleksandrova, Olga

    2014-05-01

    The environmental risk of organic xenobiotic chemicals released into soils is controlled by their sorption and binding processes. However, the molecular mechanisms of reversible and irreversible interactions of xenobiotics with soil constituents and an influence of humic substances on this interaction are only partly understood. New methods and approaches aimed at understanding of molecular mechanisms in the soil environment and a role of humic substances in the sorption and binding processes are today required to manage and keep the quality of soil used and fertilized in agricultural industry. The paper presents a new approach of using stable ESR spin labels to investigate a role of humic substances in the interactions of organic xenobiotic chemicals with constituents of natural soil via the typical functional groups of xenobiotics, such as Amines. At the experiment, the nitroxide spin labels, such as TEMPO (2,2,6,6-Tetramethylpiperidin-1-oxyl), Amino-TEMPO (4-amino-2,2,6,6-Tetramethylpiperidin-1-oxyl) and Aniline spin labels (2,5,5-Trimethyl-2-(3-aminophenyl)pyrrolidin-1-oxyl), were added to samples of different natural soils, such luvisol, cambisol and chernozem. Amino-TEMPO and Aniline spin labels include the aliphatic amino and aromatic amino functional groups, respectively. A significant broadening of the ESR spectrum of Aniline spin labels incubated in different soils indicated a stable effect of covalent binding of the spin labels to soil constituents via the aromatic amino, whereas the ESR spectra of the other two spin labels were not broadened that pointed at the absence of covalent binding of spin labels via the aliphatic amino. As shown, a part of bound spin labels via the aromatic amino increased with increasing of the concentration of humic acids in soil. The same broadened signals were also be detected with the humic acids extracted from the investigated soils. A strong covalent binding of spin labels to humic substances via the aromatic amines was

  16. Purex diluent degradation

    International Nuclear Information System (INIS)

    Tallent, O.K.; Mailen, J.C.; Pannell, K.D.

    1984-02-01

    The chemical degradation of normal paraffin hydrocarbon (NPH) diluents both in the pure state and mixed with 30% tributyl phosphate (TBP) was investigated in a series of experiments. The results show that degradation of NPH in the TBP-NPH-HNO 3 system is consistent with the active chemical agent being a radical-like nitrogen dioxide (NO 2 ) molecule, not HNO 3 as such. Spectrophotometric, gas chromatographic, mass spectrographic, and titrimetric methods were used to identify the degradation products, which included alkane nitro and nitrate compounds, alcohols, unsaturated alcohols, nitro alcohols, nitro alkenes, ketones, and carboxylic acids. The degradation rate was found to increase with increases in the HNO 3 concentration and the temperature. The rate was decreased by argon sparging to remove NO 2 and by the addition of butanol, which probably acts as a NO 2 scavenger. 13 references, 11 figures

  17. Bacterial Degradation of Pesticides

    DEFF Research Database (Denmark)

    Knudsen, Berith Elkær

    . Bioaugmentation i.e. addition of specific degrader organisms, has been suggested as an environmentally friendly and economically competitive strategy for cleaning polluted sites. Several organisms have been isolated, capable of degrading different compounds. However the capacity to degrade the desired compound...... that it was possible to produce MSH1 in large amounts within 12-24 hours. Moreover, mineralization experiments showed that the capacity to mineralize BAM was kept intact, and that maximal mineralization rate was not influenced by the state of the cells at the time of harvest (in exponential or stationary phase...... SRS2, Variovorax SRS16 and Arthrobacter globiformis D47. The degradation capacity of each strain individually as well as two- and three-member consortia was studied in a sand column set up. Glass beads were added to the set up to create a dry patch, separating the organisms and the diuron-spiked sand...

  18. How do polymers degrade?

    Science.gov (United States)

    Lyu, Suping

    2011-03-01

    Materials derived from agricultural products such as cellulose, starch, polylactide, etc. are more sustainable and environmentally benign than those derived from petroleum. However, applications of these polymers are limited by their processing properties, chemical and thermal stabilities. For example, polyethylene terephthalate fabrics last for many years under normal use conditions, but polylactide fabrics cannot due to chemical degradation. There are two primary mechanisms through which these polymers degrade: via hydrolysis and via oxidation. Both of these two mechanisms are related to combined factors such as monomer chemistry, chain configuration, chain mobility, crystallinity, and permeation to water and oxygen, and product geometry. In this talk, we will discuss how these materials degrade and how the degradation depends on these factors under application conditions. Both experimental studies and mathematical modeling will be presented.

  19. Thraustochytrid protists degrade hydrocarbons

    Digital Repository Service at National Institute of Oceanography (India)

    Raikar, M.T.; Raghukumar, S.; Vani, V.; David, J.J.; Chandramohan, D.

    Although thraustochytrid protists are known to be of widespread occurrence in the sea, their hydrocarbon-degrading abilities have never been investigated. We isolated thraustochytrids from coastal waters and sediments of Goa coast by enriching MPN...

  20. Degradation of fluorotelomer alcohols

    DEFF Research Database (Denmark)

    Ellis, David A; Martin, Jonathan W; De Silva, Amila O

    2004-01-01

    Human and animal tissues collected in urban and remote global locations contain persistent and bioaccumulative perfluorinated carboxylic acids (PFCAs). The source of PFCAs was previously unknown. Here we present smog chamber studies that indicate fluorotelomer alcohols (FTOHs) can degrade...