‘LANDFARMING’ SOIL TOXICITY FROM OIL REFINERY TREATED WITH ALGAE FOR THE EARTHWORM Eisenia fetida

Abstract

The toxicity for the earthworm Eisenia fetida from soil samples of a landfarming oil refinery was evaluated following soil inoculation with allochthonous algal community isolated from a clean soil. Soil samples from the landfarming oil refinery of Paulínia (REPLAN/PETROBRAS) were kept under hydric saturation in plastic containers, in greenhouse, during 180 days and submitted to algal inoculation, incorporation and removal of visible algal growth. After 30 days of inoculation, the community members with active growth at the initial colonization were identified at the genus level: Anabaena, Chroococcus, Scytonema and Lyngbya (Cyanophyta), Klebsormidium, Mougeotia and Oedogonium (Chlorophyta) and Navicula (Bacillariophyta). The toxicity for Eisenia fetida was evaluated with landfarming soil samples collected randomly. When acute effect in E. fetida was not observed, the effect on the biomass of adult earthworms specimens was evaluated, indicating detoxication of the landfarming soil when submitted to removal of the visible algal growth after 180 days of inoculation. The results of this study indicate that sublethal effects of the earthworm biomass are able to predict effective measurements for monitoring soil toxicity during the process of remediation.