Ecotoxicological Effects of Biodiesel in the Soil

The paper analysed the toxic effect of the presence of biodiesel in the soil. The study involved tests with microorganisms that evaluated changes in their number and activity, and phytotoxicity tests with garden cress (Lepidium sativum) and spring barley (Hordeum vulgare). Biodiesel produced in laboratory conditions and biofuel purchased at a petrol station were introduced to the soil. Two levels of contamination were used – 1% and 5% (per dry mass of the soil). Based on the results, it was discovered that biofuels both stimulated and reduced the number and activity of microorganisms. The changes observed depended on the type of biofuel and, most often, on its dose. Laboratory biodiesel exhibited more toxic effects, especially for actinobacteria and fungi. The tested plants showed diverse sensitivity to the presence of biodiesel. Given the determined value of the germination index, laboratory biodiesel was more toxic to spring barley and commercial biofuel to garden cress. In both cases, toxicity increased with an increase in the amount of biofuel.