Characterization of microbial species in a regenerative bio-filter system for VOC removal

Effective removal of volatile organic compounds (VOCs) is critical for indoor air quality (IAQ) control. The performance of existing technologies of VOC removal are limited by inadequate selection of filter media, poor airflow management inside the cleaning devices, insufficient catalytic reaction surface area, and poor distribution of UV light irradiation. A new technology based on the Wolverton air filtration system uses a plant root bed of activated carbon, porous shale pebbles, microbes and a wet scrubber to remove VOCs and radon from the air in tightly sealed buildings. To better understand this system and optimize its performance, we characterized the microbes in a model system and their activities in formaldehyde removal. We chose golden pathos as the plant and isolated the microbes from the plant roots and pebbles. By using universal primers to amplify 16S rRNA genes, 7 different strains of bacteria were identified belonging to the species of Arthrobacter aurescens, Arthrobacter oxydans Leifsonia xyli, Bacillus cereus, Pseudomonas putida and Bacillus sp. In particular, a strain of Arthrobacter aurescens TC1 isolated from this system was found to reduce the concentration of formaldehyde by 86.2% after incubation for 24 hours with a starting concentration of 11.84 ppm.