FENG Yun-gang,ZHANG Fei,FENG Kai,et al.Application of AAO Biological Tank for Denitrification Enhanced by Oxygen Elimination in a Wastewater Treatment Plant in Hefei[J].China Water & Wastewater,2021,37(14 14):80-84.
Application of AAO Biological Tank for Denitrification Enhanced by Oxygen Elimination in a Wastewater Treatment Plant in Hefei
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第37卷
Number:
14 14
Page:
80-84
Column:
Date of publication:
2021-07-17
- Keywords:
- oxygen elimination zone; varying area; enhanced phosphorus and nitrogen removal; denitrification deep bed filter; quasi Ⅳ standard
- Abstract:
- The designed treatment capacity of a wastewater treatment plant in Hefei is 20.0×104 m3/d, and the effluent quality is required to meet surface water class Ⅳ standard, among which TN in the effluent is no more than 5 mg/L. Due to the high requirement of total nitrogen in the effluent, design of biological tank should focus on nitrogen removal in order to reduce the operational cost. Based on analyzing profile of the influent quality of the wastewater treatment plant in the drainage basin in recent years, combined with the characteristics of different water temperature requirements for assessment indicators, the project focused on modification of the biological tank. Based on improvement of the five stage Bardenpho, a selection tank was added in front of the anaerobic tank, an oxygen elimination zone was set up after the aerobic zone, and the second anoxic zone was transformed into aerobic/anoxic varying zone. In this way, the nitrogen and phosphorus removal performance of the biological tank was improved, and at the same time, it could better meet different operational needs in winter, spring and summer, autumn. The advanced treatment process consisted of mixed flocculation and denitrification deep bed filter, and sodium hypochlorite was employed for disinfection. Actual operational data showed that the process flow and design parameters were reasonable and feasible, and the effluent quality could meet the discharge standard stably.
Last Update:
2021-07-19