Humic substances extraction, characterization and interaction with U(VI) at ruprechtov site (CZ)

Authors/Editors

Noseck, Ulan

Research Areas

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Publication Details

Output type: Journal article

Author list: Červinka R., Štamberg K., Havlová V., Noseck U.

Publisher: De Gruyter

Publication year: 2011

Volume number: 99

Issue number: 3

Start page: 167

End page: 178

Number of pages: 12

ISSN: 0033-8230

eISSN: 2193-3405

URL: http://api.elsevier.com/content/abstract/scopus_id:79952381432

Unpaywall Data

Open access status: closed

Abstract

The extent of complexation between natural humic acid (HA) and uranium(VI) has been investigated at the Ruprechtov natural analogue site, Czech Republic. Natural HA was extracted from the clay sediments enriched by organic matter and then characterized for their elemental composition, UV/Vis and infrared spectroscopic properties, exchange capacity and protonation constants. Moreover, the reference sample HA-leonardite was selected and studied for comparison. Complexation between natural HA and U(VI) was studied using the cation exchange technique at pH 5-6. The experimental work was focused on study dependence of U(VI) complexation with HA: i) on the concentration of HA 1-40mg/l, and ii) on the concentration of U(VI) 1×10-1×10 M. The charge neutralization model (CNM) was used for evaluation of the experimental data, modified in a way, that the total charge was divided among the individual U(VI) species in solution under given conditions. The stability constant value was determined to be log β = 4.32±0.50, LC = 50-60%, being independent on the HA concentration at U(VI) concentrations of 1×10 M. On the other hand, a dependence on the stability constant for the different U(VI) concentrations was observed. At close to real conditions of the site (U(VI)= 1×10 M and mHA =5mg/l) the stability constant log β = 6.16, LC = 50.3-52.7%. © by Oldenbourg Wissenschaftsverlag,München.

Keywords

Cation exchange, Charge neutralization model, Complexation, Czech Republic, Humic substances, Ruprechtov site, U(VI)

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