• MTBE;
  • BAC;
  • low influent concentration start-up;
  • biodegradation;
  • DGGE

Methyl tert-butyl ether (MTBE) is a common gasoline additive; it has become a worldwide groundwater pollutant. Granular activated carbon (GAC) adsorption treatment is not cost effective for removing MTBE because it is not well adsorbed. Bioaugmentation of enriched MTBE degraders originated from the soil sample of a gasoline station enhanced the performance of the column filled with the MTBE degrader containing spent GAC of the La Mirada remediation site, and made it an effective biological activated carbon (BAC) system producing a high quality effluent that will meet the US EPA's recommended <20 μg/L for source of drinking water. The carbon samples of this system were successfully employed to start up several highly efficient BAC columns in 30 days producing stable effluents under variable treatment conditions with long term effluent MTBE concentration mostly <10 μg/L, more than 99% reduction of 1–1.3 mg /L in the influent. On the basis of the similarity of 16 s rDNA sequence of the PCR-DGGE procedures, five major bacterial species of stable biochemical properties were found in the BAC effluent samples; one of the five was Bacterium RS58G, whereas the other four were uncultured bacteria. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 512–523, 2013