SHIHan-chang,WANGQiu-wan,ZHANGMing-kai,et al.Precise Aeration for the Energy Conservation and Carbon Reduction of Wastewater Treatment Plant: Optimization Algorithm and Control Strategy[J].China Water & Wastewater,2024,40(20):1-6.
Precise Aeration for the Energy Conservation and Carbon Reduction of Wastewater Treatment Plant: Optimization Algorithm and Control Strategy
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第40卷
Number:
第20期
Page:
1-6
Column:
Date of publication:
2024-10-17
- Keywords:
- precise aeration; sludge load; dissolved oxygen; nitrogen and phosphorus removal; wastewater treatment plant (WWTP); carbon reduction
- Abstract:
- This paper outlines the technical principles of precise aeration and its process optimization algorithm and the control strategy in wastewater treatment. Through its application to prove the effect of energy conservation and carbon reduction, it indicates that precise aeration is one of the important technologies for wastewater treatment plants to achieve energy conservation and carbon reduction. The research includes the principles of technology, calculation methods, and control strategies. Model software is used to simulate the process of wastewater treatment plants, to determine better operating conditions under different scenarios, and to calculate the air supply and dissolved oxygen concentration based on the optimized operating conditions. In practice, the precise aeration is realized by the control strategy of feedforward and feedback. Feedforward control includes calculating the theoretical oxygen supply according to the flow and quality of influent and adjusting the air supply concerning conditions such as blower load or frequency regulation. The feedback control is adjusted according to the deviation between the actual dissolved oxygen concentration and the setting value, ensuring that the air supply meets the actual demand and remains stable. During the implementation of control, the cascade control of dissolved oxygen concentration and air flow is adopted. This involves adjusting the opening of the valve according to the dissolved oxygen concentration and pre-adjusting the blower according to the flow trend of the air flow meter. This cascade control can reduce the fluctuation of air supply. The results show that the average power consumption of blast aeration for the removal of unit pollutants in the wastewater treatment plant is reduced from 0.418 7 kW·h/kg(COD+NH3-N) to 0.384 1 kW·h/kg(COD+NH3-N) by applying precise aeration technology. This results in an 8.2% energy savings and a 431 kgCO2-eq/d carbon reduction. At the same time, the dissolved oxygen concentration of the internal and external return sludge was reduced from 2.5 mg/L to 0.87 mg/L, potentially reducing the consumption of 489 kg carbon source (COD) in anoxic and anaerobic areas every day. Taking sodium acetate as an example, the average carbon reduction is 350 kgCO2-eq/d. Considering energy conservation and consumption reduction, 285.5 tons of carbon can be reduced every year with this technology.
Last Update:
2024-10-17