Methyl tert-butyl ether (MTBE) is a widespread groundwater contaminant, prompting the need for improved understanding of its environmental fate. This work develops an analytical method for measuring MTBE and its degradation products at environmentally relevant concentrations and applies it to laboratory studies simulating natural conditions. Results demonstrate that MTBE undergoes both biotic and abiotic degradation, with rates dependent on redox conditions and catalysts. Microbial degradation occurs under aerobic conditions but is limited in typical anaerobic fuel plumes, while specialized microbes such as strain PM‑1 can mineralize MTBE efficiently. Abiotic pathways include hydrolysis of tert-butyl formate and a Fenton-like reaction involving iron minerals and hydrogen peroxide. Together, these findings clarify key degradation pathways and kinetics governing MTBE persistence in the environment.
