Adsorption of Trace Selenium on Nano-TiO2 from Natural Water Samples

Anatase nano titanium oxide was used as a sorbent for the separation and preconcentration of selenium(IV) from liquor. The selenium was determined by hydride generation-atomic fluorescence spectrometry (HG-AFS) with KBH4-HCl. The results showed that the adsorption percentage of selenium( IV) was 92% at pH 4-6, and the elution by NaOH reached 95%. The adsorption equilibrium accorded with the Langmuir isotherm model and the maximum adsorption capacity was 32.17 m g(-1) at 293 K. The detection limit of selenium(IV) (3 sigma, n = 11) was 0.57 mu g L-1 and the relative standard deviation was 7.48%. The process has been successfully applied to the contents determination of trace selenium(IV) in some natural water samples with satisfactory results.