Domestic sewage treatment in a pilot system composed of UASB and SBR reactors.
The results obtained from the operation of a treatment system composed of an anaerobic (up-flow sludge blanket-UASB) reactor followed by an aerobic (sequencing batch-SBR) reactor treating domestic sewage are presented and discussed. The pilot plant was monitored during 6 months, aiming to obtain performance data on organic matter, nitrogen and phosphate removal under different operating conditions. The UASB reactor was operated at a constant hydraulic detention time (0) of 6 h while the SBR performance was monitored in four different duration cycles (24, 12, 6 and 4 h) corresponding to aeration times (AT) of 22, 10, 4 and 2 h, respectively. COD and TSS overall removal efficiencies (Eo) up to 91% and 84%, respectively, were achieved independently on the aeration time applied to the SBR. In respect to nitrification and phosphate removal, AT was found to be a determining operating parameter. TKN removal of approximately 90% was achieved for AT equal to or higher than 10 h; complete nitrification occurred for AT higher than 4 h; significant phosphate removal (72%) occurred only at the AT of 2 h. It was not possible to achieve simultaneous efficient removal of nitrogen and phosphate, under the operating conditions imposed on the treatment system.
Torres
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Sección Saneamiento Ambiental, Departamento de Procesos Químicos y Biológicos, Universidad del Valle, AA 25360 Cali-Colombia.
Foresti
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D001420:Bacteria, Aerobic / Q000502:physiology; D001421:Bacteria, Anaerobic / Q000502:physiology; D019149:Bioreactors; D005160:Facility Design and Construction; D009584:Nitrogen / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism; D012722:Sewage; D014865:Waste Disposal, Fluid / Q000379:methods*
D010710:Phosphates; D012722:Sewage; D009584:Nitrogen; D010100:Oxygen