Anaerobic up flow fluidized bed reactor performance as a primary treatment unit in domestic wastewater treatment

Abstract

The fluidized bed UASB performance was studied in this experiment as a primary unit the anaerobic unit the advantage of better generated sludge characteristics and smaller tank volume.The reactor performance was investigated for the treatment of domestic wastewater with unexpected industrial water flows at different operational temperatures (14–25°C) and loading rates. For each temperature range the reactor performance was studied under different hydraulic loadings HRT (6, 4, 2.5h).The best methane yield rate and COD total removal rate are 0.285l/g COD total and 70.82% respectively at warm working temperature 19°C with OLR 7.76kg COD/m3/day and HRT 6h.On the low temperature operation, the average COD removal of the reactor was 55.28% and 50.33% for HRT of 4h and 2.5h respectively. The methane production dropped to 0.1623 & 0.0988L CH4/g COD with average organic loading rate of 5.34 & 10kg COD/m3/day for HRT of 4h and 2.5h respectively.The efficiencies of Total nitrogen removal ranged between 2.23 and 10.83% with an apparent decrease during the low temperature high rate stages. Nitrite removal was in the range of (23.08–77)% with up to the 2mg/L in the effluent water when obtaining high organic loading and warm temperature. These results demonstrated that the domestic wastewater could be anaerobically treated in a fluidized bed UASB reactor with very low HRT reaching 2.5h.