Microbial Decontamination of BTEX Compounds in Batch Experimental Studies

Benzene, toluene, ethyl benzene and xylene isomer (collectively called BTEX) forms 18% by weight in a typical gasoline blend. BTEX contamination of soil and groundwater can occur by the accidental spill of gasoline, diesel fuel and leakage from underground storage tanks in pumping stations. Biodegradation is a versatile technique to remediate contaminated soil and groundwater. In the present experimental study, a mixed microbial culture obtained from the effluent treatment plant of a chemical industry was used to degrade liquid phase BTEX, at initial concentrations varying between 15 to 75 mg/l. Experiments were conducted according to the 2^k-1 fractional factorial design to identify the main effects of parameters and their influence on biodegradation of individual BTEX compounds in mixtures. A statistical interpretation of the results was done based on their F and P values. Furthermore, the removal efficiency of these compounds varied between 20 to 100% depending on the concentration of other compounds and also on their interaction effects.