| Autor: |
Guimarães LB; Department of Sanitary and Environmental Engineering, Federal University of Santa Catarina, Florianopolis, SC, Brazil.; Department of Biotechnology, Delft University of Technology, Delft, The Netherlands.; Department of Chemistry and Bioscience, Centre for Microbial Communities, Aalborg University, Aalborg, Denmark., Wagner J; Department of Sanitary and Environmental Engineering, Federal University of Santa Catarina, Florianopolis, SC, Brazil., Akaboci TRV; Department of Sanitary and Environmental Engineering, Federal University of Santa Catarina, Florianopolis, SC, Brazil., Daudt GC; Department of Sanitary and Environmental Engineering, Federal University of Santa Catarina, Florianopolis, SC, Brazil., Nielsen PH; Department of Chemistry and Bioscience, Centre for Microbial Communities, Aalborg University, Aalborg, Denmark., van Loosdrecht MCM; Department of Biotechnology, Delft University of Technology, Delft, The Netherlands., Weissbrodt DG; Department of Biotechnology, Delft University of Technology, Delft, The Netherlands.; Department of Chemistry and Bioscience, Centre for Microbial Communities, Aalborg University, Aalborg, Denmark., da Costa RHR; Department of Sanitary and Environmental Engineering, Federal University of Santa Catarina, Florianopolis, SC, Brazil. |
| Abstrakt: |
The effects of domestic wastewater and a coastal warm climate on granular sludge and biological nutrient removal were evaluated using a pilot-scale sequencing batch reactor (SBR). The reactor operation employed two different operational strategies (OS) based on up-flow feeding regimes, defined as fast (OS1, flow rate = 18.0 L min -1 and flow velocity = 22.0 m h -1 ) and slow (OS2, flow rate = 3.5 L min -1 and flow velocity = 4.3 m h -1 ). Under slow feeding, larger (OS1: 290 µm; OS2: 450 µm) and faster settling granules were obtained (OS1: 109; OS2: 74 mL g -1 TSS). The slow feeding regime was also advantageous for the hydrolysis of particulate organic matter (OS1: 1.3; OS2: 3.1 g COD tot g -1 VSS d -1 ) and for phosphorus removal (OS1: <33%; OS2: >97.5%). Neither strategy resulted in substantial biomass accumulation in the reactor (OS1: 0.7; OS2: 1.5 g VSS L -1 ), and high concentrations of nitrite were observed in the effluent (9-27 mg [Formula: see text] L -1 ). Ordinary heterotrophic organisms dominated the granular sludge developed under both feeding regimes (OS1: 30% of Thauera ; OS2: 56% of Comamonas ), while polyphosphate-accumulating organisms (PAOs) were only detected during OS2 (2.3-3.4% of total bacteria). A successful granular sludge process should be able to cope with high fluctuations in wastewater loads caused by rain events (82-182 mm month -1 in Florianopolis, Brazil). In order to achieve higher water quality, strategies identified for an efficient granular sludge SBR operation included (i) management of an anaerobic phase for PAO selection, and (ii) aeration control for successful nitrification/denitrification. |
