Bioremediation of petroleum hydrocarbon contaminated soil by bioaugmentation products

Abstract

In an experimental investigation of bioaugmentation products affected on the petroleum contaminated soil. The influence of the bioaugmentation products dose, injections and temperature on bioremediation were studied. The results showed that the degradation rate was related positively to the amount of inoculation, when the dose was increased to 0.6 mg · kg-1, total petroleum hydrocarbon (TPH) degradation rate was 87% in 48 days. The results of GC-MS indicated that the dominant petroleum constituents in oil-contaminated raw soil were 82.1% n-alkane,16% alkene and little of others hydrocarbons, such as carotane, alkylnaphthalenes, hopanes, and steranes. The peaks amount of GC profile decreased from 32 to 14 after 40 days of bioremediation, this result indicated that branched alkanes, alkene, and alkylnaphthalenes were thoroughly degraded, then line alkanes,hopanes, and steranes were left in soil. In addition, the longer part of n-alkane were degraded with rate relatively higher, while the residual fraction at the end of the test is shorter part of n-alkane because bacteria degraded the longer n-alkane to shorter. The shorter n-alkane concentration decreased with increasing inoculation. Onetime injection of bioaugmentation products into soil clearly improved the biodegradation efficiency higher than injection of bioaugmentation products in turn. Soil temperature also affected TPH degradation rate. when it was 30°C, TPH rate reached 80%, where as when it was 20°C, the TPH rate was lower to 60%, which indicated higher temperature improved TPH degradation and accelerated bioremediation.