| A literature review and laboratory study was undertaken to study the effects of chemical mixtures of hydrocarbons on the biodegradation of the individual components. Biodegradation experiments were conducted in sealed, 1-litre bioreactor/respirometer vessels containing soil spiked with various different compounds and mixtures, which were all components of diesel fuel. Degradation coefficients were determined using a first-order rate model and were based on hydrocarbon loss, O2 and CO2 respirometer data. The experimental degradation rates were found to have changed after approximately 10 days, indicating that the first-order model may not be an appropriate model for degradation greater than 10 days. Future work should incorporate multi-rate models. The presence or absence of aromatics was found to have no effect on the rate and extent of degradation of the individual compounds studied. It was also found that fungal metabolism is important for the degradation of hydrocarbons, particularly for branched species such as pristane. |
