The effects of temperature on enhanced biological phosphate removal

The effect of temperature on enhanced biological phosphate removal (EBPR) was investigated in a process treating a synthetic sewage medium with acetate as carbon source. EBPR sludge was acclimatised to temperatures of 10, 17.5 and 25 degrees C in a 5 l stirred batch reactor (SBR) operated in a continuous fed-batch manner. Batch investigations were also undertaken over a temperature range of 5-45 degrees C. Anaerobic phosphate release and aerobic phosphate uptake rates were determined. Anaerobic phosphate release and aerobic phosphate uptake were observed over a wide temperature range of 5-40 degrees C whilst at 45 degrees C both release and uptake were significantly inhibited. Q(10) and temperature coefficient (q) values were determined for both anaerobic phosphate release and aerobic phosphate uptake. Arrhenius plots described the temperature dependency of the process. Depending on the acclimatisation temperature, activation energies ranging between 33 and 35 kJ mol(-1) were determined for anaerobic phosphate release whilst activation energies ranging between 39.5 and 41 kJ mol(-1) were determined for aerobic phosphate uptake.