Organic and nitrogen removal in a two-stage rotating biological contactor treating municipal wastewater.
A laboratory scale rotating biological contactor (RBC) predenitrification system incorporating anoxic and aerobic units was evaluated for the treatment of settled high-strength municipal wastewater. The system was operated under four recycle ratios (1, 2, 3 and 4) and loading rates of 38-182 gCOD/m(2)d and 0.22-14 gOxid-N/m(2)d on the anoxic unit and 3.4-18 gCOD/m(2)d and 0.24-1.8 gNH(4)-N/m(2)d on the aerobic. The average removal efficiency in terms of chemical oxygen demand (COD), biochemical oxygen demand (BOD(5)), total suspended solids (TSS) and total nitrogen (Total-N) was 82%, 86%, 63% and 54%; settling of the RBC effluent increased COD and TSS removal to 94% and 97%. An increase in hydraulic loading resulting from higher recirculation, had limited negative effect on organic removal but improved nitrogen removal, and in terms of Total-N removal efficiency increased up to a ratio of 3 and then decreased.
Environmental Engineering Laboratory, Department of Civil Engineering, University of Patras, Patras GR-265 00, Greece.
Demetrios N
DN
Hiras
Ioannis D
ID
Manariotis
Sotirios G
SG
Grigoropoulos
D001673:Biodegradation, Environmental; D019149:Bioreactors; D006115:Greece; D009584:Nitrogen / Q000378:metabolism; D009930:Organic Chemicals / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D012044:Regression Analysis; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
D009930:Organic Chemicals; D009584:Nitrogen; D010100:Oxygen