Results 141 to 150 of about 3,638 (183)

Pyrolysis of humic and fulvic acids

Geochimica et Cosmochimica Acta, 1969
Abstract Pyrolysis of humic and fulvic acids isolated from a North Carolina soil yields a variety of aromatic, heterocyclic and straight chain organ compounds. The pyrolysis products identified by gas chromatography and mass spectrometry indicate that humic and fulvic acids have aromatic and polysaccharide structures in their molecules.
R.L. Wershaw, G.E. Bohner
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Europium binding by fulvic acids

Analytica Chimica Acta, 1998
The binding of Eu to fulvic acid (FA) as a function of pH was determined by Schubert's method and by equilibrium dialysis. Data obtained by both methods showed a strong pH dependence, which was reproduced well by the model used to interpret the data (humic ion-binding model VI).
Lead, J. R., Hamilton-Taylor, John, Peters, A., Reiner, S., Tipping, E.   +4 more
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Freezing-Enhanced Photoreduction of Iodate by Fulvic Acid

Environmental Science & Technology, 2023
Iodate is a stable form of iodine species in the natural environment. This work found that the abiotic photosensitized reduction of iodate by fulvic acid (FA) is highly enhanced in frozen solution compared to that in aqueous solution. The freezing-induced removal of iodate by FA at an initial pH of 3.0 in 24 h was lower than 10% in the dark but ...
Juanshan Du, Yi Hu, Kitae Kim, Wonyong Choi   +3 more
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Acid-base properties of aquatic fulvic acid

Analytica Chimica Acta, 1985
Abstract The acid-base properties of aquatic fulvic acid, concentrated from the Gota River, were studied by means of potentiometri titrations. The forward and reverse titrations exhibited hysteresis, which decreased as the fulvic acid underwent repeated titration.
N. Paxéus, M. Wedborg
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Acid pyrophosphate extraction of soil fulvic acids

Journal of Soil Science, 1986
SUMMARY A simple three step method is described for isolation of soil fulvic acids in high yield. The complexing agent H 2 P 2 O 7 2− (at pH 2) is used to release soil‐bound ...
J. E. GREGOR, H. K. J. POWELL
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Photooxidation of herbicide amitrole in the presence of fulvic acid

Environmental Science and Pollution Research, 2017
Fulvic acid (Henan ChangSheng Corporation) photoinduced degradation of non-UVA-absorbing herbicide amitrole (3-amino-1,2,4-triazole, AMT) as a way for its removal from polluted water was investigated in details. It was shown that the main primary species generated by fulvic acid under UVA radiation, triplet state and hydrated electron, are not directly
Ivan P, Pozdnyakov, Peter S, Sherin, Victoria A, Salomatova, Marina V, Parkhats, Vjacheslav P, Grivin, Boris M, Dzhagarov, Nikolai M, Bazhin, Victor F, Plyusnin   +7 more
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Effect of fulvic acid on neodymium uptake by goethite

Journal of Colloid and Interface Science, 2012
Experimental studies of the interaction of aqueous neodymium (Nd), Suwannee River fulvic acid (FA), and solid phase goethite were conducted. Results from blank systems (individual Nd and FA), binary systems (Nd-goethite, FA-goethite, and Nd-FA), and ternary systems (Nd-FA-goethite) at 0.1 mol/kg and 25°C are reported. In the binary Nd-goethite system a
Christopher R, Armstrong, Scott A, Wood
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Determination of fulvic acids in water

Journal of Applied Chemistry, 1959
AbstractA method for the determination of fulvic acids present in naturally‐occurring waters has been developed, based on the measurement of the ultra‐violet absorption spectrum of the sample. The method has been applied to samples of water from different parts of the country, and the results indicate that for moorland waters the fulvic acids are very ...
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Fluorescence quenching of fulvic acids by fullerene in water

Environmental Pollution, 2013
Fullerene can be suspended in water as nanoscaled-fullerene-aggregates (nC(60)). However, little is known about its biogeochemical cycling in natural waters. In this paper, the interactions between nC(60) and fulvic acids were investigated using fluorescence spectroscopy and fluorescence quenching titration.
Fengchang, Wu, Yingchen, Bai, Yunsong, Mu, Bo, Pan, Baoshan, Xing, Ying, Lin   +5 more
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Time-resolved fluorescence spectroscopy of fulvic acid and fulvic acid complexed with Eu3+ – a comparative study

Journal of Photochemistry and Photobiology A: Chemistry, 1998
Abstract In this work a systematic characterization of the fluorescence kinetics of fulvic acid by means of a single-photon time correlation technique is reported. The data were extracted from both single decay curves and time-resolved emission spectra and analyzed by the exponential series method.
C.-D Tiseanu, M.U Kumke, F.H Frimmel, R Klenze, J.I Kim   +4 more
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