Abstract
The treatment of domestic wastewater at a temperature of 12¿24°C was investigated in an RBC system. The RBC consists of a two stage system connected in series. The system was operated at different organic loading rates (OLR's) and hydraulic retntion times (HRT's) in order to optimize the RBC performance. The overall removal efficiencies for chemical oxygen demand (CODtotal, CODsuspended and CODcolloidal) significantly decreased when decreasing the total HRT from 10 to 2.5 h and increasing the OLR from 11 to 47 g COD/m2.d. However, the effluent quality of CODsoluble remained unaffected. Most of the COD was removed in the 1st stage and nitrification took place in the 2nd stage of the two stage system.The overall nitrification efficiency was 49% at total OLR of 11 gCOD/m2.d. At total HRT's of 10, 5 and 2.5 h, the Escherchia coli (E. coli) concentration was reduced by a value of 1.6, 1.5 and 0.8 log10 respectively. The sludge volume index (SVI) decreased as the OLR increased. However, the SVI of the excess sludge produced in the RBC under different OLR's was always
Original language | English |
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Pages (from-to) | 275-289 |
Journal | Water Air and Soil Pollution |
Volume | 175 |
Issue number | 1-4 |
DOIs | |
Publication status | Published - 2006 |
Keywords
- suspended-growth reactor
- domestic sewage
- supplemental aeration
- escherichia-coli
- nitrification
- performance
- oxygen
- wastewaters
- removal