title: The effect of propionic to acetic acid ratio on anaerobic-aerobic (low dissolved oxygen) biological phosphorus and nitrogen removal.
abstract: In this paper, three lab-scale sequencing batch reactors (SBR-A, B, and C) operated with anaerobic/aerobic (low dissolved oxygen, 0.15-0.45 mg L(-1)) configuration were long-term cultured, respectively with single acetic acid and propionic/acetic acid of 1/1 and 2/1 (carbon molar ratio), and the comparisons of anaerobic and aerobic transformations of phosphorus and nitrogen among them were made. With the increase of propionic/acetic acid, lower anaerobic phosphorus release and higher phosphorus release to short-chain fatty acids uptake ratio were observed, and less anaerobic and aerobic transformations of glycogen and poly-3-hydroxybutyrate as well as total polyhydroxyalkanoates occurred, but the transformations of poly-3-hydroxyvalerate and poly-3-hydroxy-2-methyvalerate increased. The phosphorus removal efficiency was respectively 81, 94 and 97% in SBR-A, B and C. Almost all ammonium was removed and no significant nitrite was accumulated at different propionic/acetic acid ratios. However, the nitrate accumulation and total nitrogen removal were observed to be affected by propionic/acetic acid ratio. The total nitrogen removal efficiency was 61, 68 and 82%, and the aerobic end nitrate concentration was 8.05, 6.40 and 3.54 mg L(-1) in three SBRs, respectively. All the above studies indicated that the sole acetic acid caused more nitrate accumulation than propionic and acetic acids mixture, and a pertinent increase of wastewater propionic/acetic acid ratio was of benefit to both nitrogen and phosphorus removal in an anaerobic/aerobic (low dissolved oxygen) biological wastewater treatment process.
authors.affiliation: State Key Lab of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China.
authors.forename: Hongjing
authors.initials: H
authors.lastname: Li
authors.forename: Yinguang
authors.initials: Y
authors.lastname: Chen
authors.forename: Guowei
authors.initials: G
authors.lastname: Gu
mesh_terms: D019342:Acetic Acid / Q000032:analysis*; D000332:Aerobiosis; D000693:Anaerobiosis; D001709:Biotechnology / Q000379:methods*; D002138:Calibration; D002241:Carbohydrates / Q000737:chemistry; D002623:Chemistry Techniques, Analytical / Q000379:methods; D006003:Glycogen / Q000737:chemistry; D008956:Models, Chemical; D009584:Nitrogen / Q000032:analysis* / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry*; D010758:Phosphorus / Q000032:analysis* / Q000737:chemistry; D011091:Polyesters / Q000032:analysis; D011422:Propionates / Q000032:analysis*; D014631:Valerates / Q000032:analysis; D018508:Water Purification
chemical_list: D002241:Carbohydrates; D011091:Polyesters; D011422:Propionates; D014631:Valerates; D010758:Phosphorus; C073314:poly(3-hydroxyvalerate); D006003:Glycogen; C029658:propionic acid; D009584:Nitrogen; D019342:Acetic Acid; D010100:Oxygen