YANG Min,GUO Xing-fang,SUN Yong-li,et al.Study on Countermeasures and Operational Problems of a WWTP with High Discharge Standard[J].China Water & Wastewater,2021,37(6 6):6-10.
Study on Countermeasures and Operational Problems of a WWTP with High Discharge Standard
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第37卷
Number:
6 6
Page:
6-10
Column:
Date of publication:
2021-03-17
- Keywords:
- enhanced biological DO removal zone; enhanced endogenous denitrification; refinement carbon source adding system; recovery of biological phosphorus removal
- Abstract:
- An upgrading and transformation project of WWTP with high discharge standard in Haihe basin, which used Bardenpho process, was taken as an example in this paper. Combining with actual operation, the main operational problems based on process diagnosis were analyzed, and the refinement countermeasures were studied accordingly. Some methods were taken to solve the problems that invalid loss of external carbon source and no endogenous denitrification effect in later anoxic tank caused by high DO of internal recycling mixed liquid and influent of later anoxic tank, which was to set enhanced biological DO removal zone by utilizing the 4th and 5th aerobic phase (HRT of 3.5 h) with unutilized tank volume. As a result, the quantity of external carbon source loss could be controlled to 15.97 mg/L COD, nitrogen removal ability of later anoxic tank by endogenous denitrification could be enhanced to 2.8 mg/L TN with utilization of 11.2 mg/L COD of internal carbon source in sludge, carbon source dosage could be decreased by 27.17 mg/L COD with decreasing extent of 54.34%, and carbon source adding cost could be saved 52 000 yuan per day. Aiming at the problem that excessive addition of carbon source in anoxic tank in some period causing 24% of aerobic tank volume to be occupied, combined with the design characteristic of anoxic tank, a fine carbon source feeding system with carbon source addition point from 1st anoxic tank to 4th anoxic tank and on-line nitrate meter in the 3rd anoxic tank and its specific operation control method were proposed. In view of the problem that excessive addition of synergistic chemicals for phosphorus removal caused activated sludge lossing biological phosphorus removal function, by taking the countermeasure that the addition point of chemicals for phosphorus removal was optimized from distributing well of secondary settling tank to coagulation with magnet unit so as to recover biological phosphorus removal function, biological phosphorus removal function could be recovered well. PO3-4-P of anaerobic tank increased from original 0.75 mg/L to 7.5 mg/L, PO3-4-P of aerobic tank effluent was 0.04 mg/L, denitrifying phosphorus removal effect was significant in anoxic tank with PO3-4-P decreasing by 2.77 mg/L, and chemical phosphorus removal medicament dosage decreased by 70% and addition cost of chemical phosphorus removal medicament could be saved by 7 000 yuan per day.
Last Update:
2021-03-17