KEShui-zhou,HUXiang,MAJing-wei,et al.Operation Optimization of Multi-stage Modified A2O Process for Nitrogen and Phosphorus Removal[J].China Water & Wastewater,2023,39(17):74-80.
Operation Optimization of Multi-stage Modified A2O Process for Nitrogen and Phosphorus Removal
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第39卷
Number:
第17期
Page:
74-80
Column:
Date of publication:
2023-09-01
- Keywords:
- modified A2O process; nitrogen and phosphorus removal; operation optimization; mass balance; sludge loading rate
- Abstract:
- This paper investigated the effects of internal reflux ratio of mixed liquid, sludge external reflux ratio and influent distribution ratio of pre-denitrification section, anaerobic section, main anoxic section and post-anoxic section on the effluent from secondary sedimentation tank of Huaqiao Water Quality Purification Plant in Changsha City, Hunan Province by orthogonal test. The internal and external reflux ratio and four-point influent distribution ratio had little influence on the removal rates of TP and NH3-N, while the influent distribution ratio of the post-anoxic section and anaerobic section had the greatest influence on the removal rate of TN. The mass balance analysis of the system indicated that the removal of nitrate nitrogen and nitrite nitrogen in the main anoxic section accounted for 70% to 80% of the total removal amount in the system, while the post-anoxic section accounted for only 10% to 20%. The rational distribution of influent carbon sources and appropriate internal reflux could maximize the nitrogen removal performance of the system. When the four-point influent distribution ratio was 15∶65∶15∶5, the internal reflux ratio was 100%, and the external reflux ratio was approximately 50%, the removal rate of TN reached the maximum of 67.82%, which was 4.74% higher than that of the control group. When the four-point influent distribution ratio was 20∶65∶15∶0, the internal reflux ratio was 50%, and the external reflux ratio was approximately 40%, the average TP in effluent from the secondary sedimentation tank in the experimental group was 0.093 mg/L lower than that in the control group. The relationship between the sludge loading rate and the pollutant removal rate in different seasons was statistically analyzed. The results showed that the optimal sludge loading rate calculated by COD was 0.15 kg/(kgMLVSS·d) in spring and summer, and 0.22 kg/(kgMLVSS·d) in autumn and winter, indicating that the purpose of reducing cost and increasing efficiency could be achieved by adjusting sludge concentration.
Last Update:
2023-09-01