Enhanced pilot bioremediation of oily sludge from petroleum refinery disposal under hot-summer Mediterranean climate

Large pilot scale bioremediation approaches were implemented for the treatments of oily sludge (OS) characterised by alkaline pH (pH > 9), high concentration metals (3% dry weight) and total petroleum hydrocarbons content (TPH) rangingbetween 22,000 67,300 mg kg ?1 from a Tunisian refinery. The included bioaugmentation biostimulation with autochthonous isolated bacterial strains consortia. Chemical, microbial, ecotoxicological analyses performed over period 180 days incubation. favoured development Proteobacteria, Firmicutes Bacteroidetes following an ecological succession specialist groups, first associated to hydrocarbon degradation (e.g. Marinobacter Alcanivorax) that resulted in greater extent TPH-degradation (up 80%), selection metal resistant bacteria including Hyphomonas, Phaeobacter, Desulfuromusa. best performances obtained when combined. Over 90% TPH initial was degraded days, which accompanied 3-fold reduction ecotoxicity. Our study demonstrates efficacy large highly contaminated sludge, providing evidence management microbial communities is paramount importance success process.