Study ecotoxicity of biodiesel from residual oils and fats and the effects of salinity aquatic ecosystems

Abstract

The increasing use of biodiesel raised concerns about its toxicological effects on the environment. However, few studies have analyzed the impact of biodiesel, especially ethyl biodiesel from residual frying oils and fats (RFOF), on aquatic organisms. Here, were used biodiesel produced by acid esterification followed the alkali transesterification and biodiesel produced by saponification, acidification and two acids esterification, both in the laboratory and their mixtures (B100, B20, and B7). The eluates were obtained by mixing biodiesel with saline water and tested the effect of several concentrations of them on the mortality rate of nauplii of the brine shrimp Artemia salina. The results of study showed that blend of diesel with greater proportion of biodiesel caused less mortality rate to A. salina nauplii. The saline eluate with 93% diesel and 7 % biodiesel (E4 and E10) showed the mortality of A. salina on 50% eluate exposure while E7 it was 90%. The mixture does increase toxicity with the presence of diesel, B100, only in E8 mortality occurred (LD50 = 100%). Conversely, the eluates ER1/100 and ER2/100 produced from ethyl biodiesel of RFOF R1 and R2 biodiesel, respectively, did not have toxicity.