Title |
Thermodynamic parameters of U (VI) sorption onto soils in aquatic systems
|
---|---|
Published in |
SpringerPlus, October 2013
|
DOI | 10.1186/2193-1801-2-530 |
Pubmed ID | |
Authors |
Ajay Kumar, Sabyasachi Rout, Malay Ghosh, Rakesh Kumar Singhal, Pazhayath Mana Ravi |
Abstract |
The thermodynamic parameters viz. the standard free energy (∆Gº), Standard enthalpy change (∆Hº) and standard entropy change (∆Sº) were determined using the obtained values of distribution coefficient (kd) of U (VI) in two different types of soils (agricultural and undisturbed) by conducting a batch equilibrium experiment with aqueous media (groundwater and deionised water) at two different temperatures 25°C and 50°C. The obtained distribution coefficients (kd) values of U for undisturbed soil in groundwater showed about 75% higher than in agricultural soil at 25°C while in deionised water, these values were highly insignificant for both soils indicating that groundwater was observed to be more favorable for high surface sorption. At 50°C, the increased kd values in both soils revealed that solubility of U decreased with increasing temperature. Batch adsorption results indicated that U sorption onto soils was promoted at higher temperature and an endothermic and spontaneous interfacial process. The high positive values of ∆Sº for agricultural soil suggested a decrease in sorption capacity of U in that soil due to increased randomness at solid-solution interface. The low sorption onto agricultural soil may be due to presence of high amount of coarse particles in the form of sand (56%). Geochemical modeling predicted that mixed hydroxo-carbonato complexes of uranium were the most stable and abundant complexes in equilibrium solution during experimental. |
Mendeley readers
Geographical breakdown
Country | Count | As % |
---|---|---|
Unknown | 21 | 100% |
Demographic breakdown
Readers by professional status | Count | As % |
---|---|---|
Researcher | 4 | 19% |
Student > Doctoral Student | 3 | 14% |
Student > Bachelor | 3 | 14% |
Professor > Associate Professor | 3 | 14% |
Student > Ph. D. Student | 2 | 10% |
Other | 2 | 10% |
Unknown | 4 | 19% |
Readers by discipline | Count | As % |
---|---|---|
Environmental Science | 8 | 38% |
Earth and Planetary Sciences | 3 | 14% |
Agricultural and Biological Sciences | 1 | 5% |
Pharmacology, Toxicology and Pharmaceutical Science | 1 | 5% |
Physics and Astronomy | 1 | 5% |
Other | 1 | 5% |
Unknown | 6 | 29% |