Assessment of selenium compounds use in limitation of petroleum impact on antioxidant capacity in sandy soil / Ocena wykorzystania związków selenu w ograniczeniu oddziaływania substancji ropopochodnych na pojemność antyoksydacyjną gleby lekkiej

The aim of this study is to assess the selenium (on two oxidation states +IV and +VI) effect on antioxidant capacity in light soil contaminated with gasoline and diesel fuel. The soil used in experiment is characterised by granulometric composition of loamy sand with organic carbon content of 8.7 g·kg⁻¹. Different combinations of gasoline or diesel fuel in dosage 1 or 5%, and H₂SeO₃ and H₂SeO₄ in dosage 0.05 mmol Se·kg⁻¹ were added into soil. In the period of 35 days at weekly intervals, antioxidant capacity of the soil in methanol and alkali extracts was determined. Soil contamination with petroleum caused the decrease in antioxidant capacity. Selenium application increased in antioxidant capacity in extracts. In the case of uncontaminated soil, this effect was higher for selenium on the oxidation state +VI, and in soil that contained petroleum for selenium on the oxidation state +IV.