title: Investigation of strontium sorption onto Kula volcanics using Central Composite Design.
abstract: In performance assessment studies, the uptake of the radioactive elements by rock formations play an important role in retarding their aqueous phase migration. Sorption studies of radionuclides have been conducted to obtain data on the distribution coefficient (K(d)) that is as an input parameter in the performance assessment of the geological disposal of radioactive wastes. In this work, sorption experiments were studied in a batch sorption system using Sr(NO(3))(2) solution on non-treated and HCl-treated Kula volcanics. The distribution coefficient (K(d)) values of Sr(2+) derived from batch experiments were used to evaluate the migration behavior of Sr(2+). Central Composite Design was used in the experiments. Sr sorption was studied as a function of pH, temperature, initial concentration of adsorbate and contact time. The results show that the K(d) values are higher at pH 7-9 which is the pH range of the natural waters. The kinetic data conformed better to the pseudo-second-order equation. Thermodynamic parameters ΔH°, ΔS° and ΔG° were estimated and these parameters show that adsorption is endothermic. The correlation coefficients indicate that the Langmuir model fits better for the strontium sorption onto non-treated and HCl-treated Kula volcanics with monolayer capacities as 2.04 and 1.72 mg/g, respectively.
authors.affiliation: Ege University, Institute of Nuclear Sciences, 35100 Bornova, İzmir, Turkey. ceren.kutahyali@ege.edu.tr
authors.forename: Ceren
authors.initials: C
authors.lastname: Kütahyalı
authors.forename: Berkan
authors.initials: B
authors.lastname: Cetinkaya
authors.forename: M Bahadır
authors.initials: MB
authors.lastname: Acar
authors.forename: Nuray Olcay
authors.initials: NO
authors.lastname: Işık
authors.forename: Irfan
authors.initials: I
authors.lastname: Cireli
mesh_terms: D000327:Adsorption; D019015:Geologic Sediments / Q000737:chemistry*; D007700:Kinetics; D008855:Microscopy, Electron, Scanning; D011834:Radiation Monitoring; D011848:Radioactive Pollutants / Q000302:isolation & purification*; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D013324:Strontium / Q000302:isolation & purification*; D013499:Surface Properties; D014421:Turkey; D018707:Volcanic Eruptions
chemical_list: D011848:Radioactive Pollutants; D012996:Solutions; D013324:Strontium