Biofilm growth and hydrodynamic behaviour in the biological plate tower (BPT) with and without hanging biomass (BPT-HB)

摘要

Deodorization and volatile organic compound abatement from polluted air streams can beaccomplished with the biological plate tower (BPT), which has proved to be a reliable alternative tobiofilters and biotrickling filters. Unlike those, the BPT is a non-clogging device, with constant activesurface, and steady performance, making it ideal for scale-up and modelling. The initial BPT designneeded improvement for better performance. The cylindrical body (circular plates) was replaced by arectangular cuboid (rectangular plates). Holes in the plates did augment the amount of activebiomass (hanging from the holes and under the plates), without reducing the transfer of toluene fromthe gaseous to the liquid phase. The diminished distance between plates was well tolerated in cocurrentflow, allowing much higher quantities of biomass in the same reactor volume. With 18 and14 mm spacing between adjacent plates, the BPT, with and without holes, was tested for flooding,holdup and pressure drop. Several gas and liquid flows were tested, both in co-current and countercurrent.In hydrodynamic terms, the BPT-HB with co-current flow was clearly the best option. Higherstability with higher flow rates, and lower pressure drops were observed. The inoculum was obtainedfrom wastewater plant activated sludge (petrochemical industry).