On-site bioremediation of soil contaminated by no. 2 fuel oil

✍ Scribed by Jyunkai Shen; Richard Bartha

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 606 KB
• Volume: 33
• Category: Article
• ISSN: 0964-8305
• DOI: 10.1016/0964-8305(94)90055-8

✦ Synopsis

Bench-scale and pilot-scale on-site bioremediation studies were conducted on subsurface soil contaminated by a leaky underground fuel tank 20 years earlier. Its gas chromatographic profile identified the contaminant as No. 2 fuel oil. C02 evolution rates in biometer flasks indicated that the hydrocarbon residue was suitable for bioremediation treatment. Of the contaminated soil, 25 m 3 were excavated, surface spread and treated by liming, fertilization and tilling. In addition to hydrocarbon residues, pH, humus content and acute toxicity (Microtox) were monitored during the bioremediation process. In two growing seasons, the initial hydrocarbon concentration of 10 200 ppm declined to 250ppm. Compared to the background of clean soil (ECso = 220 I~g), initially the contaminated soil was moderately toxic (ECso = 44 #g). Due to the metabolic intermediates of hydrocarbon biodegradation, soil toxicity increased substantially during the first 2 months of treatment (ECso = 3 Itg), but returned to the level of clean soil early in the second growing season. Variations in tilling frequency ranging from twice per week to once every 2 weeks did not significantly influence the rate of hydrocarbon degradation.