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Wyszukujesz frazę "caesium distribution" wg kryterium: Temat


Wyświetlanie 1-2 z 2
Tytuł:
Uptake and distribution of caesium and its influence on the physiological processes in croton plants (Codiaeum variegatum)
Autorzy:
Bystrzejewska-Piotrowska, G.
Jeruzalski, M.
Urban, P.
Powiązania:
https://bibliotekanauki.pl/articles/147293.pdf
Data publikacji:
2004
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
bioremediation
o caesium uptake
caesium distribution
croton plants
phytoextraction
Opis:
Croton (Codiaeum variegatum) belongs to the salinity-resistant plants. This paper presents some experimental data in order to assess usefulness of croton plants for phytoremediation of caesium-contaminated soils. The plants were grown in a greenhouse, in the soil contaminated with 0.03, 0.3, 1, 3, 5 and 10 mM CsCl solution enriched with 137Cs as a radiotracer. The croton plant demonstrated high resistance to increasing CsCl salinity of the soil. This conclusion was based on the observation that the above-ground organ fresh-to-dry weight ratio was constant. However, this value was lower for the roots. The young-to-old leaf dry weight ratio was decreasing while the concentration of CsCl in the soil was increasing. The increase in soil CsCl concentration was associated with the decrease in photosynthesis as well as a rise in the intra-tissue concentration of CO2 and increase of the CO2 stomatal conductance. Photosynthetic water utilization efficiency was constant in the range of 0.03-1 mM CsCl and it was only lower with higher CsCl concentration. This situation gives an evidence that croton plant is highly resistant to the soil CsCl salinity. The 137Cs radiotracer experiment showed the maximal accumulation of caesium with 0.3 mM CsCl, a lower one with 0.03 mM, and poor accumulation with 3 and 5 mM CsCl solutions. The transfer factor value for 137Cs (plant-to-soil) was about 10, which proved a high ability of croton plants to accumulate caesium to a high extent. However, the highest accumulation took place in the roots. The intensive phytoextraction of caesium from the soil may indicate its potential capacity for bioremediation. The reported observation warrants further studies.
Źródło:
Nukleonika; 2004, 49,suppl.1; 35-38
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental and modelling investigation of caesium adsorption on soil samples around DAE facility, India
Autorzy:
Maity, Sukanta
Sandeep, Police
Sahu, Sanjay Kumar
Kumar, A. Vinod
Powiązania:
https://bibliotekanauki.pl/articles/1030685.pdf
Data publikacji:
2020
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
CEC
Laboratory batch method
caesium
chemical parameters
distribution coefficient (Kd)
equilibration time
isotherm
rate constant
Opis:
The kinetics and thermodynamics behind the sorption process of Cs (Caesium) on the soil are important to understand as these studies give information about the mobility of Cs in the environment. In the present study, sorption kinetics and the parameters influencing sorption (viz. time of contact, competing ions, temperature, solution pH and Cs concentration) were studied on the soil samples collected from Tarapur area. Site-specific distribution coefficient (Kd) of Cs was also estimated in soil samples collected from different locations across Tarapur, India using laboratory batch method. The effect of soil parameters (viz. pH, cation exchange capacity, organic matter and CaCO3) on Kd values of Cs was also investigated. The data of Cs adsorption on the soil is well fitted with the pseudo-second-order kinetic equation with the correlation coefficient (R2) value of 0.99. The rate constant (k2) of Cs adsorption (at 25 ºC) on collected soil samples was found to be 3.33×105 g µg-1 min-1. In the present study, Cs adsorption data were well fitted with Freundlich and Dubinin–Radushkevich (D–R) isotherm models. The change of enthalpy (ΔH), entropy (ΔS) and Gibbs free energy (ΔG) were estimated for the Cs adsorption on soil samples. Results showed that the adsorption process was exothermic (ΔH = -3.69 J mol−1) and favoured at a lower temperature. The calculated ΔG value (< 0) indicates that the Cs sorption on the soil is a spontaneous process. The Kd values were found to the range of 58 ± 2 to 275 ± 10 kg-1. The parametric study indicated CEC to have a stronger influence as compared to pH, OM and CaCO3 in the soil samples.
Źródło:
World Scientific News; 2020, 139, 2; 201-220
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-2 z 2

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