Effects of acetate and nitrite addition on fraction of denitrifying phosphate-accumulating organisms and nutrient removal efficiency in anaerobic/aerobic/anoxic process.
The effects of acetate and nitrite on the performance of sequencing batch reactors (SBRs) employing an anaerobic/aerobic/anoxic (AOA) process were investigated. Three types of SBR operations were used: sodium acetate addition at the start of anoxic condition for heterotrophic denitrification (Type 1); sodium acetate addition at the start of aerobic condition for anoxic phosphate removal by denitrifying phosphate-accumulating organisms (DNPAOs) (Type 2: conventional AOA process); and nitrite addition at the start of aerobic condition for inhibition of phosphate-accumulating organisms (PAOs) (Type 3). A track experiment shows that Type 2 led to the best performance of SBRs among the three types. An analysis by fluorescence in situ hybridization (FISH) revealed that nitrite addition decreased the ratio of PAOs with a decrease in phosphorus removal efficiency. The fraction of DNPAOs in Type 2 was the highest at 13%, indicating that Type 2 is suitable for the simultaneous nitrogen and phosphorus removal in the AOA process.
Soejima
Koichi
K
Department of Chemical Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan.
Oki
Kazuma
K
Terada
Akihiko
A
Tsuneda
Satoshi
S
Hirata
Akira
A
D000085:Acetates / Q000008:administration & dosage*; D001420:Bacteria, Aerobic / Q000187:drug effects / Q000378:metabolism*; D001421:Bacteria, Anaerobic / Q000187:drug effects / Q000378:metabolism*; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology*; D003198:Computer Simulation; D007700:Kinetics; D008954:Models, Biological; D009573:Nitrites / Q000008:administration & dosage*; D009584:Nitrogen / Q000302:isolation & purification / Q000493:pharmacokinetics*; D010710:Phosphates / Q000493:pharmacokinetics*
D000085:Acetates; D009573:Nitrites; D010710:Phosphates; D009584:Nitrogen