Biodegradation of isobutyraldehyde with high removal efficiency by using a modified biotrickling filter

Isobutyraldehyde is a kind of Volatile organic compounds (VOCs) released by the butanol industry, which has a low olfactory threshold and high hydrophobicity, causing harm to the environment. Biotrickling filters have been widely used for VOCs treatment. Herein, a biotrickling filter (BTF-1) inoculated with the domesticated bacteria was used to degrade isobutyraldehyde. However, low dissolved oxygen, unstable temperature, high-pressure drop, and excessive foams were observed due to structural and technical problems. Hence, a modified BTF-2 was established to revise these problems by adding an oxygenation device, separating the tower kettle, and adding a recirculating water layer. Finally, the maximum elimination capacity (EC) (195 g/(m3·h)) and average removal efficiency (RE) (90%) were achieved at an empty bed residence time (EBRT) of 46 s and inlet flow rate of 500 L/h. Furthermore, 16S rDNA analysis identified Clostridiales as the prominent bacteria group in charge of isobutyraldehyde degradation. Overall, the feasibility and efficiency of using a biotrickling filter for isobutyraldehyde treatment were confirmed in this investigation, which would provide technical support for the industrial scale-up of BTF to biodegrade isobutyraldehyde.