Effect of full and partial-bed configuration on carbon removal performance of biological aerated filters.

A comparative study to explore the characteristics of partially and fully packed biological aerated filters (BAFs) in the removal of carbon pollutant, reveals that the partial-bed reactor can perform comparably well with the full-bed reactor. The organic removal rate was 5.34 kg COD m-3 d-1 at Organic Loading Rates (OLR) 5.80 ± 0.31 kg COD m-3 d-1 for the full-bed, and 5.22 kg COD m-3 d-1 at OLR 5.79 ± 0.29 kg COD m-3 d-1 for the partial-bed. In the partial-bed system, where the masses of biomass were only 41-51% of those of the full-bed, the maximum carbon removal limit was still between 5 to 6 kg COD m-3 d-1. At organic loadings above 5.0 kg COD m-3 d-1, the carbon removal capacity in both systems was limited by the mass and activity of microorganisms. The SRT in the full and partial-bed reactors was primarily controlled by the biomass loss in the effluent and during backwash operation. The SRT was reduced from 20.08 days at OLR 4.18 ± 0.20 kg COD m-3 d-1 to 7.62 days at OLR 5.80 ± 0.31 kg COD m-3 d-1 in the full-bed, and from 7.17 days to 4.21 days in the partial-bed. After all, SRT values in the partial-bed were always lower than those in the full-bed. [ABSTRACT FROM AUTHOR]