[Energy saving achieved by limited filamentous bulking under low dissolved oxygen: experimental validation in A/O process].
Preliminary studies had been conducted to determine the correctness of the theory and technique of energy saving achieved by limited filamentous bulking under low DO using a lab-scale A/O reactor with real domestic wastewater as the influent. The results showed that SVI could be maintained 150-230 mL/g and sludge settleability would not become very poor under the condition of low DO. During the period of limited filamentous bulking, COD and total nitrogen removal efficiencies were improved, and distinct simultaneous nitrification and denitrification (SND) was achieved, while ammonia removal efficiency would slightly decline with decreasing of DO, compared with the period of good settleability sludge under high DO. COD, ammonia and total nitrogen removal efficiencies were 86%, 70% and 63%, respectively. It was found that about 10%-25% nitrogen would be removed by SND based on the mass balance of nitrogen. Besides, SS in the effluent was almost negligible and the effluent turbidity was lower than 3 NTU. Significantly, aeration consumptions would be decreased by 17% under the condition with DO of 0.5 mg/L compared with 2.0 mg/L according to theoretical calculation of air requirements to keep different DO levels, which was about 57% in lab-scale reactor correspondingly.
Guo
Jian-hua
JH
School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China.
Wang
Shu-ying
SY
Peng
Yong-zhen
YZ
Zheng
Ya-nan
YN
Huang
Hui-jun
HJ
Ge
Shi-jian
SJ
Sun
Zhi-rong
ZR
D000641:Ammonia / Q000737:chemistry / Q000302:isolation & purification; D001421:Bacteria, Anaerobic / Q000502:physiology*; D001673:Biodegradation, Environmental; D004868:Equipment Failure; D005427:Flocculation; D009584:Nitrogen / Q000737:chemistry / Q000302:isolation & purification; D010100:Oxygen / Q000737:chemistry / Q000378:metabolism*; D012037:Refuse Disposal / Q000379:methods*; D012722:Sewage / Q000737:chemistry* / Q000382:microbiology; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis
D012722:Sewage; D014874:Water Pollutants, Chemical; D000641:Ammonia; D009584:Nitrogen; D010100:Oxygen