Biofiltration of Hexane Vapor Under Intermittent Loading: Effect of Operating Temperature and Kinetic Analysis

Biofiltration is a common biological technique to remove volatile compounds from waste air streams. According to industrial overview, they should be flexible in various temperatures, inlet loads and types of aeration. In this research, a laboratory scale compost biofilter inoculated with unidentified fungi consortium was set up to eliminate different loads of n-hexane in the temperature range of 30-45˚C under intermittent loading. A complete removal of n-hexane was observed at 30 and 35˚C. Increasing the inlet load to 598 gm-3h-1 at 35˚C only reduced removal efficiency to 82% under and the maximum elimination capacity obtained 491 gm-3h-1 in this situation. Increasing the temperature to 45˚C intensively reduced the removal efficiency. It seemed that the reduction of the performance in higher temperatures could be as a result of limitation in diffusing the pollutant from gas into liquid phase. The results exhibited that the biological reaction rate followed linearly with logarithmic mean concentration along the bed during intermittent loading at 30, 35 and 40˚C.