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ABSTRACT
Benzene, toluene, and xylene (BTX) gases are suspected carcinogens that also have offensive odors. Dispersion of these substances to the ambient air may lead to adverse effects on the environment such as photochemical smog and endanger human health and welfare. As a technology for controlling BTX, biofiltration has several advantages over traditional BTX control technologies: public acceptance as an "environmentally friendly". Because various kinds of waste gases are simultaneously emitted from a source, the effect of mixed gas on the removal efficiency of each gas cannot be ignored. MTBE (Methyl tert-Butyl Ether) as a gasoline additive is often released together with BTX, so that the effect of MTBE on the biodegradation of BTX is a prerequisite for biofilter design and operation. This study evaluated the effect of MTBE on the BTX degradation in a polyurethane biofilter inoculated by a BTX-degrading microbial consortium. The maximum elimination capacities (MEC) of BTX and MTBE were 200, 250, 450, and 100 g m-3 h-1, respectively. By the addition of MTBE, the MEC of BTX became 75, 100, and 300 g m-3 h-1, respectively, so benzene was most inhibited by MTBE. The MEC of MTBE was placed in the range of 0 to 50 g m-3 h-1. In a mixture of three gases (BTX), the removal capacities of BTX were 50, 90, and 200 g m-3 h-1, respectively, and became 40, 50, and 100 g m-3 h-1 by the addition of MTBE. In conclusion, the existence of MTBE revealed an inhibitory effect on the degradation of each gas of BTX for a single and BTX-mixture gas.
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