FAVORABLE COMBINATIONS OF TREATMENT SySTEMS Activated sludge reactors Mechanical treatment 10-3um 10-um 0.1um 1um 10-2mm 01mm 1mm 10mm 102mm Biofilm reactors Chemical treatment Treatability of municipal wastewater
10-4µm 10-3µm 10-2µm 0.1µm 1µm 10-2mm 0.1mm 1mm 10mm 102mm Treatability of municipal wastewater Activated sludge reactors Biofilm reactors Chemical treatment Mechanical treatment FAVORABLE COMBINATIONS OF TREATMENT SYSTEMS
EXAMPLES FROM SCANDINAVIAN WWT PLANTS Fraction of suspended COD and BOD Q0,9 o0.9 30,8 0.8 0.7 0,7 0.6 ■o0 90.6 0.5 0,5 04 0.4 0, 3 o Sweden 0, 3 o Sweden 802№rway 旨02№w 0.1 ▲ Finland 0.1 LL ▲ Finland 0 2004006008 100 200 300 400 Total coD Total boD
0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 0 200 400 600 800 Total COD Fraction of suspended COD Sw eden Norw ay Finland 0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1 0 100 200 300 400 Total BOD Fraction of suspended BOD Sw eden Norw ay Finland Fraction of suspended COD and BOD EXAMPLES FROM SCANDINAVIAN WWT PLANTS
PROCESSES TAKING PLACE IN THE SEWER SySTEM lgh gradient areas Low gradient areas Aerobic conditions Anaerobic conditions n sewer In sewer VFA +O? cells Particulate COD-O2→ no Biofilm hydrolysis→VFA Biofilm
High gradient areas Low gradient areas Aerobic conditions Anaerobic conditions in sewer in sewer VFA + O2 cells Particulate COD - O2 hydrolysis VFA O2 Biofilm Biofilm no O2 PROCESSES TAKING PLACE IN THE SEWER SYSTEM
R aw Water DENS ADEG T reated water Fecl3 Polymer Pres ettler Sludge recirc lation Sludge draw-off R or T hickner / settler
DE NS ADEG T reated Water R eactor T hickener / S ettler S ludge recirculation S ludge draw-off F eCl3 R aw Water Polymer Presettler ?
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