Use of integrated phytoremediation for cleaning-up of oil-sludge-contaminated soil

The possibility of using multicomponent systems, including plants, mineral fertilizers, and plant growth promoting microorganisms, has been studied in vegetative experiments in order to stimulate phytoremediation of oil-sludge-contaminated soil. Winter rye ( Secale cereale L.) was used as the principal phytoremediating plant species, whereas alfalfa ( Medicago sativa L.), nitrogen fertilizer (ammonium nitrate), and a PGPR strain ( Azospirillum brasilense SR80) were applied as additional components, individually or in various combinations. The obtained data revealed the critical importance of alfalfa for phytoremediation of hydrocarbon-contaminated soil. Application of different multicomponent treatments resulted in approximately 70% reduction of pollutant concentration in soil. The developed technological approaches were successfully tested in the remediation of an ex-oil-sludge pit on the ground of a petroleum refinery.