Quantification of MTBE and TBA biodegradation

Abstract

Methyl tertiary butyl ether or MTBE is often used as an additive in gasoline to boost the octane rating and to promote more efficient combustion of the gasoline. This widespread use of MTBE has resulted in serious soil and groundwater pollution. To tackle MTBE contamination in groundwater, bioremediation is considered a cost-effective and energy-efficient option. The design of an efficient, reliable and reproducible bioremediation strategy requires a thorough understanding of the (microbial) degradation kinetics of both MTBE and TBA (tertiary butyl alcohol), i.e., the main intermediate during bioremediation of MTBE. To assist the design procedure, this research focuses on building a low complexity, yet accurate mathematical model to describe MTBE/TBA degradation kinetics by a bacterial consortium, i.e., the VITO M-consortium.The resulting model provides an accurate description of MTBE/TBA degradation and has successfully been validated on independent experimental data. Since the model is of the mass balance type, it can easily be extended to other types of operation by defining the transport terms of the new system. This makes the model a very useful tool in the design procedure for large scale bioremediation strategies. Furthermore, the model provides insight in the MTBE/TBA degradation kinetics and biodegradation mechanisms by hypothesis testing.