LU Wen-juan,WANG Hao-long,YUAN Lin-jiang.Effect of Ratio of Hydraulic Retention Time between Anoxic Zone and Aerobic Zone on Sludge Bulking[J].China Water & Wastewater,2021,37(15 15):77-82.
Effect of Ratio of Hydraulic Retention Time between Anoxic Zone and Aerobic Zone on Sludge Bulking
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第37卷
Number:
15 15
Page:
77-82
Column:
Date of publication:
2021-08-01
- Keywords:
- anoxic zone; aerobic zone; hydraulic retention time; sludge bulking
- Abstract:
- Variations in purification performance and sludge settleability in a continuous flow A/O denitrification system fed with synthetic wastewater were investigated when ratios of anoxic zone hydraulic retention time to aerobic zone hydraulic retention time were 1 ∶3, 1 ∶2 and 2 ∶1, respectively, and relationship between ratio of anoxic hydraulic retention time to aerobic hydraulic retention time and sludge bulking in the system were explored. When the ratio increased from 1 ∶3 to 1 ∶2, nitrogen removal efficiency of the system increased from 50% to 80%, and sludge volume index (SVI) decreased from 250 mL/g to 110 mL/g, which greatly improved the sludge settleability and inhibited the sludge bulking. Then, the ratio was adjusted to 2 ∶1, the maximum nitrogen removal efficiency reached 88%, and the value of SVI was between 180 mL/g and 210 mL/g. In the three stages, degradation degree of particle substrate in the anoxic zone was different with different anoxic hydraulic retention time, and the residual substrate concentration in the aerobic zone affected the dominant filamentous bacteria in the system, so it also affected the floc structure and settling performance of the sludge. In addition, dominant microbial community could be affected by changing the anoxic and aerobic hydraulic residence time in the system, so as to improve the sludge bulking.
Last Update:
2021-08-01