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Influence of copper (II) ions on stability of dissolved humic acids - coagulation studies

100%

Boguta P., Sokolowska Z.

Acta Agrophysica

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2013

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tom 20

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nr 2

The main aim of the paper was to study the effect of coagulation of copper ions on dissolved form of humic acids. Research material was isolated from four peaty muck soils (Terric Histosols). The soils were described by means of the Springer humification number, secondary transformation index, ash content and pH in H2O and in KCl. For the studied humic acids, surface charge was determined, E4/E6 which described the degree of concentration of the chain of aromatic carbons of the humic acids and could be used as their humification number, and the elemental composition and atomic ratios were determined as well. Systems composed of humic acids and increasing concentrations of copper ions were investigated at pH 5 and in the copper concentration range of 0-40 mg dm-3, at constant concentration of humic acids. Coagulation of solutions was studied by measurement of changes of organic carbon and copper ions concentration in liquid phase at pH 5 as well as by observation of absorbance changes at wavelength 465 nm in series of prepared solutions. The results showed that coagulation of experimental systems consisted mainly in humic acid coagulation. In a certain range of concentration of copper added to solutions, metal also partly precipitated and went to the solid phase together with humic carbon, which indicated coagulation of complexed compound of humic acids with copper. At high copper concentration, ionic strength had a dominant influence on coagulation of humic acids. Copper ions stayed all in liquid phase, whereas almost total organic carbon passed to precipitate, which resulted from interactions with electrolyte ions.

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Preliminary investigations of relative polarity of dissolved humic substances in select lakes of the Elk District, Poland

80%

Glazewski R., Wojcik I.

Polish Journal of Environmental Studies

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2009

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tom 18

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nr 4

599-606

The reported study describes the separation of humic substances (HS) dissolved in surface waters into hydrophilic and hydrophobic fractions with the SPE method onto StrataX (Phenomenex) columns. The separated fractions were analyzed with the HPLC-C18 (Merck column) method for relative polarity of humic (HA) and fulvic (FA) acids in the samples. Analyses were carried out on samples collected from 7 lakes constituting two cascade systems located in the same catchment of the Ełk River. During HPLC assays, an effect of size exclusion (SE) was observed, especially for the hydrophilic fraction. The HPLC analyses enabled us to demonstrate that in both hydrological systems the hydrophilic fraction contained mainly molecules with molecular weights exceeding 1,000Da and of practically equal relative polarity. Only in system II (five lakes) was the hydrophobic fraction strongly diversified quantitatively as well as in terms of molecular weight and polarity between the samples. Results of analysis show that this system was subject to a strong anthropogenic impact.

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The structure of phosphorus compounds in mid-forest humic lakes

80%

Joniak T.

Oceanological and Hydrobiological Studies

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2010

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tom 39

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nr 2

4

Diel dynamics of vertical changes of chlorophyll and bacteriochlorophyll in small humic lakes

80%

Joniak T., Klimaszyk P., Kraska M.

Oceanological and Hydrobiological Studies

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2010

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tom 39

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nr 3

Ograniczanie wyników

2 Oceanological and Hydrobiological Studies

1 Acta Agrophysica

1 Polish Journal of Environmental Studies

2 Joniak T.

1 Boguta P.

1 Glazewski R.

1 Klimaszyk P.

1 Kraska M.

1 Sokolowska Z.

1 Wojcik I.

1 2013

2 2010

1 2009

Influence of copper (II) ions on stability of dissolved humic acids - coagulation studies

Preliminary investigations of relative polarity of dissolved humic substances in select lakes of the Elk District, Poland

The structure of phosphorus compounds in mid-forest humic lakes

Diel dynamics of vertical changes of chlorophyll and bacteriochlorophyll in small humic lakes