Use this url to cite ETD: https://hdl.handle.net/20.500.12259/113690
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Kalcio jonų įtaka kadmio jonų adsorbcijos-desorbcijos procesams skirtingos granuliometrinės sudėties dirvožemiuose
Field of Science
Ekologija ir aplinkotyra / Ecology and environmental sciences (N012)
Type of publication
type::text::thesis::master thesis
Title
Kalcio jonų įtaka kadmio jonų adsorbcijos-desorbcijos procesams skirtingos granuliometrinės sudėties dirvožemiuose
Other Title
The influence of calcium ions on cadmium adsorbtion-desorbtion processes in the soils of various texture
Author
Muraškaitė, Vaiva |
Advisor
Extent
56 p.
Date Issued
2005-06-07
Abstract
In this master work the influence of calcium ions on the cadmium mobility in the sandy and clay soils was investigated. Work subject - samples of Orthieutric Fluvisol and Calcaric-Endohypogleyic Luvisol topsoils taken from arable lands in Balbieriskis distirict. Work objective - to investigate the influence of calcium ions on the cadmium adsorption-desorption processes in the model systems of different kind of soil-Cd(NO3)2-Ca(NO3)2 simulating pH, Cd2+ and Ca2+ amounts. Work methods - the investigated soil samples were agitated for 1 hour with Cd(NO3)2 and Ca(NO3)2 solutions of various concentrations. The solutions were made in the 0.03M NaNO3 for the constant ionic strength maintaining. The Cd amounts in the equilibrium solution after the adsorption were determined with atomic absorption spectrometer (AAS). The Cd desorption was investigated in the samples after adsorption using 0.05M NH4-EDTA (pH 7) solution as extractant. The Cd amount in extract was determined with AAS. Work results - results of the research showed that in the clay soil were accumulated more mobile Cd ions under the influence of Ca ions than in the sandy soil. The clay soil adsorbed for 25 % less and desorbed for 77 % more mobile Cd ions than sandy soil. When soil contamination with Cd was increased from 8 till 40 mg/kg, the Cd adsorption increased about 17 % in both alkaline (pH 8) and acidic (pH 4) medium, while in the sandy soil it decreased about 7 % at pH 8 and increased about 3 % at pH 4. The Cd desorption from the clay soil at that time decreased around 47 % independently on medium acidity. Whereas, the Cd desorption decreased only about 3 % from alkaline sandy soil (pH 8) and about 3 % increased from acidic sandy soil (pH 4). Increasing Ca amount in the simulated system from 10 till 40 g/kg decreased the Cd adsorption for 17 % in the clay and for 11 % in the sandy soil, while the Cd desorption it increased about 3 % in both the clay and the sandy soils when there were 8 mg/kg Cd2+ in the system. When Cd2+ amount was more (40 mg/kg), its’ desorption from clay soil was more intensive and reached 16 %. Also, it was established, that increasing soil pH increased the Cd adsorption in soils about 15 % in clay and about 10 % in sandy in spite of increasing Ca amount only at less soil contamination level (8 mg/kg Cd2+), but had less influence on the Cd desorption only at more contamination with Cd soil level (40 mg/kg): it decreased Cd desorption about 10 % from clay and about 4 % from sandy soil. Consequently, the Ca additive increases the Cd mobility in the soil as well as negative environmental influence.
Language
Lietuvių / Lithuanian (lt)
Defended
Taip / Yes
Access Rights
Atviroji prieiga / Open Access