Impact of the Treatment of Oily Sludge on Microbial Communities Structure by Composting

The degradation dynamics of total petroleum hydrocarbon(TPH) and the structure of microbial communities were investigated in the process of composting oily sludge. The removal efficiency of TPH in oily sludge was 53.3%±9.5% with compost treatment after 90 d incubation, which was significantly higher than that with control treatment(P0.05). Average well color development(AWCD) of Biolog ECO plates showed that there were significant differences of carbon substrate utilization patterns between two treatments(P0.05). The high AWCD value of compost treatment suggested that the soil microbial activity was enhanced by composting, which might be responsible for the enhanced degradation of petroleum hydrocarbon. The principal components analysis of the Biolog data indicated that two treatments were clearly separated from each other. Furthermore, 16S rRNA gene clone library analysis indicated that dominant populations of microbial community in the control and composting treatment were γ-Proteobacteria and Bacteroidetes respectively. Marinobacter and Alcanivorax which were abundant in the control treatment might naturally monitor degradation of petroleum hydrocarbon, and Pusillimonas and Agrobacterium which were rich in the composting treatment might also involve in the degradation of petroleum hydrocarbon.