Natural and Technical Phytoremediation of Oil-Contaminated Soil

Natural and technical phytoremediation approaches were compared for their efficacy in decontaminating oil-polluted soil. We examined 20 oil-contaminated sites of 800 to 12,000 m(2) each, with different contamination types (fresh or aged) and levels (4.2-27.4 g/kg). The study was conducted on a field scale in the industrial and adjacent areas of a petroleum refinery. Technical remediation with alfalfa (Medicago sativa L.), ryegrass (Lolium perenne L.), nitrogen fertilizer, and soil agrotechnical treatment was used to clean up 10 sites contaminated by oil hydrocarbons (average concentration, 13.7 g/kg). In technical phytoremediation, the per-year decontamination of soil was as high as 72-90%, whereas in natural phytoremediation (natural attenuation with native vegetation) at 10 other oil-contaminated sites, per-year decontamination was as high as that only after 5 years. Rhizodegradation is supposed as the principal mechanisms of both phytoremediation approaches.

Automated summary

This study compared the effectiveness of natural and technical phytoremediation approaches in decontaminating oil-polluted soil. The research examined 20 oil-contaminated sites of different contamination types and levels. Technical remediation with specific plants and agrotechnical treatment achieved a higher yearly decontamination rate compared to natural phytoremediation with native vegetation. It is believed that rhizodegradation is the main mechanism for both phytoremediation approaches.