MtBE biodegradation in a gravity flow, high-biomass retaining bioreactor.

Area of Science:

• Environmental Science
• Environmental Engineering
• Microbiology

Background:

• Methyl tert-butyl ether (MtBE) is a common fuel oxygenate contaminating groundwater.
• Effective remediation technologies are needed to address widespread MtBE pollution.

Purpose of the Study:

• To evaluate the efficiency of a pilot-scale Biomass Concentrator Reactor (BCR) for aerobic biodegradation of MtBE.
• To identify microbial communities involved in MtBE degradation within the BCR.

Main Methods:

• Operation of a pilot-scale Biomass Concentrator Reactor (BCR) for one year.
• Monitoring of MtBE and tert-butyl alcohol (TBA) concentrations in influent and effluent.
• Analysis of dissolved organic carbon (DOC) in water samples.
• Microbial community profiling using 16S rDNA gene denaturing gradient gel electrophoresis (DGGE).

Main Results:

• The BCR achieved over 99.9% treatment efficiency for MtBE.
• Effluent MtBE and TBA concentrations were below 2.9 and 0.9 microg/L, respectively, during stable operation.
• Effluent water quality improved, with lower dissolved organic carbon than influent tap water.
• Bacterial genera Hydrogenophaga, Methylobacterium, Sphingomonas, and Pseudomonas, known for MtBE degradation, were identified.

Conclusions:

• The BCR is a highly efficient technology for removing MtBE from contaminated water.
• The bioreactor supports a diverse microbial community capable of degrading MtBE.
• The BCR's operational simplicity and low maintenance make it a potentially cost-effective solution for groundwater remediation.