Steady- and transient-state performance of a thermophilic suspended-growth bioreactor for α-pinene removal from polluted air.

The removal of α-pinene from polluted air was examined under thermophilic conditions (50°C) in one- and two-liquid phase continuous stirred tank bioreactors (CSTBs). Steady-state experiments were performed at different gas residence times, and α-pinene concentrations, corresponding to inlet loading rates between 0.5 and 38gm(-3)h(-1) in the one-liquid phase CSTB, and between 2.9 and 176gm(-3)h(-1) in the two-liquid phase CSTB. The presence of a second liquid-phase (5% v/v silicone oil) increased the maximum elimination capacity (85.7gm(-3)h(-1)) by ∼6-fold compared to the one-liquid phase CSTB. During transient-state experiments, the CSTB with silicone oil could withstand a higher α-pinene shock load (110gm(-3)h(-1)) than the CSTB operated without silicone oil (70gm(-3)h(-1)). Besides, the thermophilic specific substrate utilization rates were estimated from batch assays, reaching 89 and 340μgα-pinenemgbiomass(-1)d(-1), in the absence of or presence of silicone oil, respectively.