GUIZhi-gang,HEJun-guo,ZENGXin-hui,et al.Startup and Operation Efficiency of Shortcut Nitrification and Denitrification Process in AO Reactor Induced by UVA[J].China Water & Wastewater,2024,40(11):8-12.
Startup and Operation Efficiency of Shortcut Nitrification and Denitrification Process in AO Reactor Induced by UVA
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第40卷
Number:
第11期
Page:
8-12
Column:
Date of publication:
2024-06-01
- Keywords:
- activated sludge; UVA; AO reactor; shortcut nitrification and denitrification; biological nitrogen removal
- Abstract:
- Ultraviolet A (UVA, 365 nm) with a strength of 232.96 μW/cm2 was used to irradiate activated sludge, the feasibility of achieving shortcut nitrification and denitrification of urban sewage was studied under continuous flow conditions,and the effects of UVA on the activity of ammonia-oxidizing bacteria (AOB), nitrite-oxidizing bacteria (NOB) and denitrifying bacteria were investigated.In a continuous flow AO reactor, the effects of no UVA irradiation and UVA irradiation were compared. Under the conditions of normal temperature, influent COD of 100 mg/L and NH4+-N of 50 mg/L, the nitrogen removal rate of without UVA irradiation and with UVA irradiation reached more than 50% and over 80% respectively after 80 days of operation, indicating that the experimental group successfully realized the shortcut nitrification and denitrification.The effect of UV irradiation on AOB was very small, and the activity value was about 8 mg/(gVSS·h). While the activity of NOB was reduced from about 10 mg/(gVSS·h) without UVA irradiation to about 2 mg/(gVSS·h). It is speculated that this is related to the mechanism that UVA can induce microbial oxidative stress effects. NOB generally lacks corresponding antioxidant enzymes, resulting in the inability to effectively clear intracellular reactive oxygen species (ROS) in a short period of time. UVA irradiation increased the activity of denitrifying bacteria from 8 mg/(gVSS·h) to about 12 mg/(gVSS·h).
Last Update:
2024-06-01