ZHOUYa-liang,ZHOUZan-min,YUZhi-da,et al.Optimization of Phosphorus and Nitrogen Removal Process with Low Organic Pollutant Concentration[J].China Water & Wastewater,2022,38(24):102-107.
Optimization of Phosphorus and Nitrogen Removal Process with Low Organic Pollutant Concentration
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第38卷
Number:
第24期
Page:
102-107
Column:
Date of publication:
2022-12-17
- Keywords:
- low organic pollutant concentration; nitrogen and phosphorus removal; process optimization; whole process analysis
- Abstract:
- After upgrading, the discharge limits of total nitrogen and phosphorus were reduced from 20 mg/L and 1 mg/L to 15 mg/L and 0.5 mg/L, respectively, in a municipal wastewater treatment plant (WWTP) in South China. In the rainy season, the low influent organic concentration (BOD5 is 50-60 mg/L) and the fluctuation of BOD5/TN ratio below 4 in 80% cases result in the lack of carbon source in the process of biological nitrogen removal and the greater pressure of effluent total nitrogen to meet the standard. By whole process analysis according to the research result and practice, the process operation mode is changed from the improved A2/O oxidation ditch to AO mode flexibly. At the same time, by monitoring influent and effluent orthophosphate concentration timely and adjusting the dosage of PAC reasonably, when the influent BOD5/TN ratio is at 2-3 analogously, the total effluent nitrogen concentration decreased by about 36%, and the total phosphorus was stably controlled below 0.3 mg/L. The control effect is good and stable, thus the annual carbon source cost is saved by about 2.70 million yuan/a.
Last Update:
2022-12-17