Effect of Carbon Source on Biological Nitrogen and Phosphorus Removal in an Anaerobic-Anoxic-Oxic, (A2O) Process

The effects of acetate and propionate on biological nitrogen and phosphorus removal in a plug-flow A(2)O process were evaluated in this study. The wastewater quality indexes and operation parameters were the same when different carbon sources were used. However, we observed no obvious effect of carbon source on nitrogen removal. Denitrifying phosphorus removal was found to play an important role in simultaneous nitrogen and phosphorus removal in anoxic reactors because almost the entire carbon source was used for polyhydroxyalkanoate (PHA) synthesis in anaerobic reactors, and there was no external carbon source left for heterotrophic denitrification. Propionate was found to be a more effective and energy-saving carbon source for biological nitrogen and phosphorus removal. In addition, the variations in the metabolic chemicals, such as phosphorus, PHA, glycogen, and oxygen, were lower when propionate was used than when acetate was used.