Performance and kinetics of rotating drum biofilter aerobic simultaneous purifying SO2 and NOx.

The rotating drum biofilter (RDB) was investigated as a biological process for purifying SO2 and NOx. After 25 days of film hanging, the inlet concentration was less than 2800 mg·m-3, and the NOx inlet concentration was less than 800 mg·m-3, with greater than 90% desulphurisation and denitration efficiency. Bacteroidetes and Chloroflexi were the dominant bacteria in desulphurisation, while Proteobacteria were the dominant bacteria in denitrification. The sulphur and nitrogen in RDB were balanced when the SO2 inlet concentration was 1200 mg·m-3 and the NOx inlet concentration was 1000 mg·m-3. The best results were obtained SO2-S removal load was 28.12 mg·L-1·h-1 and NOx-N removal load was 9.78 mg·L-1·h-1. when SO2 concentration was 1200 mg·m-3, NOx concentration was 800 mg·m-3, and empty bed retention time (EBRT) was 75.36 s. The liquid phase dominated the SO2 purification process, and the experimental data fit better with the liquid phase mass transfer model. NOx purification was governed by the biological and liquid phases, with the modified biological-liquid phase mass transfer model fitting the experimental data better.