Bioscrubbing of low concentrations of isopropanol from air stream

123In Phases I and II, which lasted a total of 114 days, corresponding to the startup and development of the biofilm on the packed PP balls for the BTF, the gas rate and influent IPA concentration were maintained at 0.328 m3/min and 6-911 mg/m3, respectively, and pH of the scrubbing liquid was measured to be in the range of 5.3-6.6. The BTF was then operated for 43 days (Phase III) at an influent gas rate of 0.512 m3/min, which is equivalent to an EBRT of 8.2 s for the gas through the packed section. IPA concentrations in the influent gas were kept in the range of 18-292 mg/m3. As shown in Fig. 2, the performance of the biofilter during this phase was good with IPA removal efficiencies near 100% except a day.The results showed that the performance of experimental BTF did not affected by the fluctuating influent IPA concentration with EBRTs of longer than 8 s.