Comparative assessment of acute and chronic ecotoxicity of water soluble fractions of diesel and biodiesel on Daphnia magna and Aliivibrio fischeri

The widespread use of diesel as a transportation fuel and the introduction of biodiesel into the world energy matrix increase the likelihood of aquatic contamination with these fuels. In this case, it is important to know the environmental impacts caused by water-soluble fraction (WSF) of these fuels, since it is the portion that can result in long-term impacts and affect regions far away from the location of a spill. Therefore, we evaluated and compared the aquatic ecotoxicity of the WSF of biodiesel and diesel through acute ecotoxicity tests with the aquatic microcrustacean Daphnia magna and the marine bacteria Aliivibrio fischeri, as well as chronic ecotoxicity tests with D. magna. The WSF of diesel was 2.5-4 folds more toxic than the WSF of biodiesel in acute ecotoxicity tests. Similarly, a comparison of the chronic ecotoxicity demonstrated that the WSF of diesel was more toxic than the WSF of biodiesel. WSF of diesel causes chronic effects on reproduction, longevity and growth of D. magna (NOEC was 12.5, 12.5, 6.25%, respectively), while WSF of biodiesel did not present significantly different results compared to the control for any of the parameters evaluated in any of the dilutions tested (NOEC> 25%). To the best of our knowledge, this is the first study that compares the chronic ecotoxicity of WSF of diesel and biodiesel on D. magna. (C) 2019 Elsevier Ltd. All rights reserved.