Biodegradation of gaseous benzene with microbial consortium in a biofilter

The objective of this study was to investigate the biodegradation of gaseous benzene in a biofilter inoculated with benzene-oxidizing microorganisms. The biofilter performance was monitored in terms of benzene removal efficiency and carbon dioxide production. The biofilter was capable of achieving as much as 96% benzene removal efficiency at a residence time of 2 min and an inlet concentration of 220 ppm. During operation with an inlet benzene of 220 ppm, the maximum elimination capacity of the biofilter was 483 g of C6H6 m(-3) day(-1). Under the same conditions, carbon dioxide with a concentration of up to 726 ppm was produced. It was found that carbon dioxide was produced at a rate of 608 mg day(-1), which corresponded to a volume of 0.351 day(-1). Observable features of the microorganisms, meaning microbial activity occurrence in the biofilter, were investigated with the microscopy analysis.