A model for diffusion controlled bioavailability of crude oil components

Area of Science:

• Environmental Science
• Microbiology
• Petroleum Geochemistry

Background:

• Crude oil is a complex mixture containing biodegradable and non-biodegradable components.
• Microbial degradation of crude oil is influenced by the physical and biochemical properties of its constituents.
• The interaction between biodegradable and non-biodegradable fractions affects degradation rates.

Purpose of the Study:

• To investigate the impact of non-biodegradable material concentration on the transport of biodegradable crude oil components to microorganisms.
• To develop a mathematical model for crude oil biodegradation based on a bioavailability parameter.
• To quantify the relationship between asphaltene concentration and crude oil biodegradability.

Main Methods:

• Systematic alteration of non-biodegradable material (asphaltenes) concentration in crude oil.
• Analysis of biodegradable component transport to microorganisms.
• Development and application of a mathematical model incorporating a bioavailability parameter.
• Measurement of oxygen uptake in respirometers to assess biodegradation rates.

Main Results:

• Increased asphaltene concentration led to a decrease in maximum oxygen uptake, indicating reduced biodegradation.
• The fitted bioavailability parameter for degradable oil components decreased with rising asphaltene concentration.
• This suggests that asphaltenes impede the bioavailability of degradable oil fractions.

Conclusions:

• Asphaltenes act as a limiting factor in the microbial biodegradation of crude oil.
• The bioavailability parameter effectively models the inhibitory effect of asphaltenes on biodegradation.
• Understanding these interactions is vital for predicting and enhancing bioremediation strategies for oil spills.