Study of MTBE biodegradation in aerobic condition

The fuel oxygenate methyl tert-butyl ether (MTBE) are added into gasoline for the purposes of octane enhancement and reduction of air pollution. Due to significant dissolution of MTBE into the aqueous phase and limited sorption to soil, MTBE plumes in contaminated groundwater are generally longer and more stable than co-existing gasoline plumes. In situ bioremediation is an alternative to traditional technologies because it is considered to be cost-effective and energy efficient In the first step of this survey, the influence of various factors such as mixed culture type, incubation time, microbial culture and optimal concentration of MTBE on the aerobic degradation of MTBE were investigated in shaking flasks and the most important factors were specified by means of fractional factorial design ½ . In the second stage by using optimal valuse which obtained from first stage, the effects of cosubstare parameter and inoculum parameter were assayed by means of response surface methods. The results of the experiments showed that the mixed culture type and initial concentration of MTBE were the most significant factors. the indigenous mixed culture of the area in one of the experiments showed about 31 percent MTBE biological treatment at the presence of n-hexane as co-substrate with 200 ppm initial concentration of MTBE