Removal of Se⁶⁺ Ion from Wastewater with Lead Compounds

Abstract

In the present work the adsorption of selenium six valence electrons from Na₂SeO₄ solution was investigated. The lead compound 1,000 mg·dm^-3 showed the ability to adsorb Se⁶⁺ ion from the Se⁶⁺ ion solution.
Under the experimental conditions of Se⁶⁺ ion concentration = 30 mg·dm^-3 and pH = 3~9, the Se⁶⁺ ion adsorbed amount was about 0.025 kg·kg^-1.
When the experimental conditions were: pH = 7 and 100 mg·dm^-3 Se ⁶⁺ ion concentration in the solution, maximum adsorbed Se⁶⁺ ion amount was 0.041 kg·kg^-1. Using x-ray photoelectron spectroscopy, the changes of the adsorbed Se⁶⁺ ion to Se⁴⁺ and Se⁰ were observed as Molybdomerite was formed.
On the other hand, the absorption of Pb cations from the lead solution was investigated. When 2000 mg·dm^-3 fly ash was mixed with 40 mg·dm^-3 lead solution, the concentration of the lead solution was under 0.1 mg·dm^-3 after 1 hour.
The adsorption of Se-cations from the selenium wastewater was observed. When 0.02 kg·dm^-3 lead compound was mixed with 70 mg·dm ^-3 selenium wastewater, the concentration of the selenium wastewater was under 0.1 mg·dm^-3 after 30 minutes.
The removal of selenium ion from actual wastewater is possible.