Se(IV)/Se(VI) adsorption mechanisms on natural and on Ca-modified zeolite for Mediterranean soils amended with the modified zeolite: prospects for agronomic applications.

Autor: Zafeiriou I; Laboratory of Soil Science and Agricultural Chemistry, Department of Natural Resources Management & Agricultural Engineering, School of Environment & Agricultural Engineering, Agricultural University of Athens, 11855, Athens, Greece., Gasparatos D; Laboratory of Soil Science and Agricultural Chemistry, Department of Natural Resources Management & Agricultural Engineering, School of Environment & Agricultural Engineering, Agricultural University of Athens, 11855, Athens, Greece., Ioannou D; Laboratory of Soil Science and Agricultural Chemistry, Department of Natural Resources Management & Agricultural Engineering, School of Environment & Agricultural Engineering, Agricultural University of Athens, 11855, Athens, Greece., Katsikini M; Department of Physics, Aristotle University of Thessaloniki, GR 54124, Thessaloniki, Greece., Pinakidou F; Department of Physics, Aristotle University of Thessaloniki, GR 54124, Thessaloniki, Greece., Paloura EC; Department of Physics, Aristotle University of Thessaloniki, GR 54124, Thessaloniki, Greece., Massas I; Laboratory of Soil Science and Agricultural Chemistry, Department of Natural Resources Management & Agricultural Engineering, School of Environment & Agricultural Engineering, Agricultural University of Athens, 11855, Athens, Greece. massas@aua.gr.
Jazyk: angličtina
Zdroj: Environmental science and pollution research international [Environ Sci Pollut Res Int] 2023 Mar; Vol. 30 (14), pp. 41983-41998. Date of Electronic Publication: 2023 Jan 14.
DOI: 10.1007/s11356-022-24979-2
Abstrakt: In the present study, the ability of a modified CaCl 2 zeolite (Ca-Z) to both increase Se(IV) availability and restrict Se(VI) mobility in soils is examined. As it was resulted from batch experiments and verified by X-ray absorption fine structure (XAFS) and X-ray fluorescence (XRF) spectroscopies, higher amounts of both Se species adsorbed on Ca-Z compared to natural zeolite (Z-N) forming outer-sphere complexes while the oxidation state did not alter during agitation of samples. Thereafter, Ca-Z was incorporated in six Greek soils, divided into acid and alkaline, at a 20% (w/w) rate and a series of equilibrium batch experiments were performed with soils alone and soils-Ca-Z mixtures to investigate sorption and desorption processes and mechanisms. The acid soils, either treated with Ca-Z or not, adsorbed higher amounts of Se(IV) than alkaline ones, whereas soils alone did not adsorb Se(VI) but impressively high adsorption of Se(VI) occurred in the Ca-Z-treated soils. Desorption of Se(IV) was higher from the Ca-Z-treated soils and especially from the acid soils. Higher distribution coefficients of desorption than the distribution coefficients of sorption were observed, clearly pointing to a hysteresis mechanism. The experimental data fitted with Langmuir and Freundlich isotherms. In the presence of Ca-Z, the Langmuir q m values increased indicating higher Se(IV) retention while Langmuir b L values decreased suggesting lower bonding strength and higher Se(IV) mobility. Overall, treating the soils with Ca-Z increased Se(IV) adsorption and mobility whereas it provided sites for Se(VI) adsorption that did not exist in the studied soils.
(© 2023. The Author(s).)
Databáze: MEDLINE
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