Effects of injection of acetic acid and propionic acid for total phosphorus removal at high temperature in enhanced biological phosphorus removal process

• Published in: Water science and technology Vol. 69; no. 10; pp. 2023 - 2028
• Main Authors: KI, C. Y, KWON, K. H, KIM, S. W, MIN, K. S, LEE, T. U, PARK, D. J
• Format: Journal Article
• Language: English
• Published: London International Water Association 01-01-2014; IWA Publishing
• Subjects: Accumulation; Acetates; Acetic acid; Acetic Acid - chemistry; Aerobiosis; Anaerobic processes; Anaerobiosis; Applied sciences; Bioaccumulation; Biological activity; Bioreactors; Carbon; Carbon sources; Chemical oxygen demand; Efficiency; Exact sciences and technology; Glycogen; High temperature; Hot Temperature; Inflow; Influents; Microorganisms; Phosphorus; Phosphorus - chemistry; Phosphorus removal; Pilot Projects; Pollution; Propionates - chemistry; Propionic acid; Rain; Rainfall; Removal; Sewage; Temperature; Temperature effects; Time Factors; Waste Disposal, Fluid - methods; Wastewater; Wastewater treatment; Wastewater treatment plants; Water Pollutants, Chemical - chemistry; Water treatment and pollution; PAOs; Temperature; external carbon source; Phosphorus; Injection; Carbon; phosphorus removal
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2014.090

In summer, wastewater treatment plant total phosphorus (TP) removal efficiency is low in South Korea. The reason is because of high temperatures or significant fluctuation of inflow characteristics caused by frequent rainfall. Hence, this study tried to raise TP removal efficiency by injecting fixed external carbon sources in real sewage. Polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) compete to occupy microorganisms at high temperature. Propionate is known to restrain GAOs. Thus, acetate and propionate were chosen as the external carbon source in this study to find out the suitable volume and ratio of carbon source which ensured the dominance of PAOs. An external carbon source was supplied in the anaerobic reactor of the biological phosphorus removal process at high temperature (above 25 °C). TP removal efficiency was improved by injecting an external carbon source compared to that without an external carbon source. Also, it remained relatively stable when injecting an external carbon source, despite the variation in temperature. TP removal efficiency was the highest when injecting acetate and propionate in the proportion of 2:1 (total concentration as chemical oxygen demand (COD) is 12 mg/L in influent).