Nitritation and denitritation of domestic wastewater using a continuous anaerobic-anoxic-aerobic (A(2)O) process at ambient temperatures.
In a continuous anaerobic-anoxic-aerobic (A(2)O) process treating domestic wastewater at ambient temperatures, nitritation was achieved through a combination of short aerobic actual hydraulic retention time (AHRT) and low dissolved oxygen (DO) levels (0.3-0.5mg/L). The nitrite accumulation rate was about 90% and ammonia removal efficiency was over 95%. With respect to total nitrogen removal, nitritation-denitritation at low DO levels of 0.3-0.5mg/L was essentially equal to the complete nitrification-denitrification at DO levels of 1.5-2.5mg/L with the addition of external carbon sources. Regardless of low DO operation, sludge bulking did not occur since the sludge volume index was below 150ml/g. Real-time PCR assays showed that in response to complete and partial nitrification modes, the numbers of ammonia oxidizing bacteria population were 5.28x10(9)cells/g MLVSS and 3.95x10(10)cells/g MLVSS, respectively. Achievement of nitritation-denitritation is highly beneficial to the treatment of domestic wastewater in terms of lower carbon requirements and reduced aeration costs.
Zeng
Wei
W
Key Laboratory of Beijing for Water Environment Recovery, Department of Environmental Engineering, Beijing University of Technology, 100124 Beijing, China. zengwei_1@263.net
Li
Lei
L
Yang
Yingying
Y
Wang
Shuying
S
Peng
Yongzhen
Y
D000332:Aerobiosis; D000641:Ammonia / Q000378:metabolism; D000693:Anaerobiosis; D001419:Bacteria / Q000235:genetics / Q000378:metabolism; D001673:Biodegradation, Environmental; D009566:Nitrates / Q000032:analysis; D009573:Nitrites / Q000032:analysis; D009584:Nitrogen / Q000378:metabolism*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012722:Sewage / Q000737:chemistry / Q000382:microbiology; D012995:Solubility; D013696:Temperature; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods*; D018508:Water Purification / Q000379:methods*
D009566:Nitrates; D009573:Nitrites; D012722:Sewage; D000641:Ammonia; D009584:Nitrogen; D010100:Oxygen