Selenium extractability from a contaminated fine soil fraction: implication on soil cleanup.

摘要: Two batches of fine soil fraction an acidic were deliberately contaminated with selenite (Se(IV)) and selenate (Se(VI)), respectively, aged for more than 220 days. Speciation analysis using continuous flow-through hydride generation atomic absorption spectrometry (HGAAS) indicated that the species predominant in their respective soils. A selective sequential extraction scheme was employed to fractionate Se retained soils into six fractions varying retentions. Abilities various chemical reagents extracting two then evaluated. The investigated sodium salts such as chloride (NaCl), sulfate (Na2SO4), carbonate (Na2CO3), phosphate (Na3PO4), oxidants, namely, hydrogen peroxide (H2O2) potassium permanganate (KMnO4). It found NaCl, Na2SO4, Na2CO3 could only extract exchangeable Se, while Na3PO4 strongly-bound fractions. Selenate extracted Se(IV) by salts. kinetics be best described Elovich model, Ritchie second-order model most appropriate describe Se(VI) extraction. Efficiencies oxidants highly depended on applied dosages. Both H2O2 KMnO4 able greater 93% total therefore significantly effective