Temperature and carbon source effect on EBPR culture enriched at high temperature

Many studies reported that it is challenging to apply enhanced biological phosphorus removal (EBPR) process at high temperature. Glycogen accumulating organisms (GAOs) could easily gain their dominance over poly-phosphate accumulating organisms (PAOs) when the operating temperature was in the range of 25^oC to 30^oC. Moreover, almost all the studies about temperature effect indicated C and P turnover rates were lower at higher temperature than lower temperature. The EBPR culture enriched at lower temperature was employed in those studies. However, a few successful EBPR processes operated at high temperature have been reported recently while few study focused on the temperature effect on the EBPR culture enriched at higher temperature. Thus, we studied the temperature and carbon source effect on the EBPR culture enriched at higher temperature. The C and P turnover rates (i.e., P release rate, carbon uptake rate, PHA synthesis rate, PHA degradation rate and P uptake rate etc.) were higher at higher temperature than lower temperature with all carbon sources using the EBPR culture enriched at higher temperature. The PHA/P ratios were lower with all the carbon sources at 30^oC than 20^oC which indicated more phosphorus would be up taken consuming the same amount of PHA at 30^oC. The Gly/PHA ratios indicated the amount of glycogen synthesis consuming per mol PHA. The ratios were lower with all carbon sources at 30^oC than 20^oC. EBPR performance was better at higher temperature than lower temperature using the EBPR culture enriched at higher temperature. Moreover, EBPR performance was best with C2 in which PHB was the major component of PHA.