Effects of soil types on the biodegradation of crude oil by Nocardia sp. H17-1

Abstract

The degradation and mineralization of crude oil were investigated over 50-days in three soils, loamy sand, sand, and combusted loamy, which were artificially contaminated with crude oil (50 g kg-1) and inoculated with Nocardia sp. H17-1. The degradation efficiency of total petroleum hydrocarbon (TPH) in sand was the highest at 76% among the three soils. The TPH degradation rate constants (kTPH) in loamy sand, sand, and combusted loamy sand were 0.027 d-1, 0.063 d-1, and 0.016 d-1, respectively. In contrast, the total amount of CO2 evolved was the highest at 146.1 mmol in loamy sand. The CO2 evolution rate constants (kCO2,) in loamy sand, sand, and combusted loamy sand were 0.057 d-1, 0.066 d-1, and 0.037 d-1, respectively. Therefore, it seems that the degradation of crude oil in soils can be proportional to the soil pore space and that mineralization can be accelerated with the increase of organic substance.