| Bioremediation is a growing technology for treating fuel contaminated soils, with many biological, physical and chemical factors controlling the rate and efficiency of this process. Using sealed respirometers in a controlled laboratory environment, the effect of temperature, oxygen concentration, and nitrogen sources on the degradation rate of diesel fuel in soil was investigated. Hydrocarbon degradation rates increased with increasing temperature, and with increasing oxygen concentrations. Nitrogen sources affected the degradation rates, with ammonium sulfate and urea providing the best degradation rates. Ammonium nitrogen was responsible for the degradation, while evidence suggests that nitrate was inhibitory. Carbon dioxide evolution and oxygen consumption underestimate the diesel fuel loss rates in all cases. There is evidence to suggest that denitrification was occurring in some of the experiments, and was responsible for the observed difference. Findings suggest the use of custom made fertilizers for bioremediation projects. |
