Microcalorimetric investigation of effects of petroleum pullution on soil microbial activity

TAM III multi-channel calorimetry was applied to study the effect of different concentrations petroleum on soil microbial activity. The soils samples from different wells of Dagang Oil field (3683-5-1, West 51-5, West 15-14, 8-13-6H-1) were detected. At the same time, serials of soils with different concentrations of petroleum (control, 0.5%, 1.5%, 2.5%, 4.0%) were prepared to study their short-time effect on microbial community activity. As the oil content increased, the total heat evolution increased, the microbial growth rate constant decreased, the peak-heat output powers increased first and then started to decline when reached a certain concentration, and the times of the peak delayed after crude petroleum added. The results indicate that the soil microbial activity was promoted at the lower concentration but then inhibited accordingly with increasing concentrations of petroleum.