Keywords: sequencing batch reactors, cycle period, phosphorus removal, environmental technology, substrate composition, wastewater treatment
Effect of cycle period and substrate composition on phosphorous removal potential of a laboratory-scale sequencing batch reactor
The performance of a laboratory-scale sequencing batch reactor (SBR) of 20-litre capacity was evaluated for simultaneous removal of soluble COD (SCOD), NH
+?N and phosphorus by changing the compositions and concentrations of substrates under different combinations of REACT period. The total cycle period of 10 h comprised 0.5 h FILL period, 8 h REACT period, 1 h SETTLE period and 0.5 h IDLE/DRAW period with the react period being divided into two combinations of anoxic (A) and aerobic (O) react period namely (4 h + 4 h) (A/O) and (3 h + 3 h + 2 h) (A/O/A). The initial SCOD concentration was kept constant at 2000 mg/l while the initial NH
+?N concentrations were taken as 90 mg/l and 180 mg/l as N tentatively. Results for total phosphorus accumulation capacity indicated that the A/O/A combination was more conducive to total phosphorus uptake at 90.26 mg P/g MLVSS than the A/O combination in the aerobic reaction period which followed the initial 3-h anoxic react period.