The low oxygenation efficiency of rotational flow aerators may be caused by various factors. The following are some directions for identifying the reasons:
1. Challenges inherent in mechanical filters
Micro-pore aerator blockage: Impurities in wastewater, microbial flocs, organic chemical precipitates, etc. may clog the air outlet of the micro-pore aerator, preventing gas from being discharged evenly and smoothly, thereby affecting oxygenation efficiency. For example, when treating industrial wastewater, heavy metal ions in the sewage may combine with hydroxide ions in the water to produce hydroxide precipitates, which adhere to the surface of the micro-pore aerator and block the air outlet.
Mechanical filter aging: Long-term use of mechanical filters may lead to various issues such as aging, cracking, and hardening of rubber gaskets and other parts, resulting in gas leakage or uneven distribution. Taking rubber gasket mechanical filters as an example, after exceeding the service life of 5 years, the valve plate may develop tiny cracks due to long-term fatigue from expansion and contraction, preventing gas from effectively generating vortex flow and reducing oxygenation efficiency.
The selection of mechanical filter model is unreasonable: Different sewage water bodies, water flow rates, and processes have varying requirements for mechanical filters. If the specifications and models of the rotational flow aerators are incorrect, such as using an undersized mechanical filter in a wastewater tank with a large water volume, or selecting an unsuitable type of mechanical filter for high-concentration wastewater treatment, the desired oxygenation effect cannot be achieved.
2. Process index challenges
Insufficient aeration rate: This is one of the common reasons for low oxygenation efficiency. Insufficient aeration rate may be caused by factors such as an inappropriate fan model, common faults in centrifugal fans, blocked drainage pipes, or insufficient regulating valves. When the air supply from the fan cannot meet the design requirements of the mechanical filter, the mechanical filter cannot generate a strong enough swirl flow, reducing the contact surface and time between O2 and water, and consequently decreasing oxygenation efficiency.
Too short aeration time: In wastewater treatment processes, aeration time is a crucial factor determining the actual oxygenation effect. If the aeration time is too short, the dissolved oxygen in the water has not reached saturation before the next treatment stage begins, resulting in low oxygenation efficiency. Generally speaking, different types of wastewater treatment processes have different requirements for aeration time. For example, the aeration time for activated sludge is usually 6-12 hours. If the specific aeration time is only 3-4 hours, it is difficult to ensure good oxygenation effect.
There is a problem with the water level: The oxygenation efficiency of the rotational flow aerator is related to the water level to some extent. If the water level is too shallow, the gas will have too short a residence time in the water, and O2 will precipitate out of the river surface before it can fully dissolve; if the water level is too deep, although the gas will stay in the water for a longer time, the excessive water pressure will also increase the resistance of the mechanical filter, making it impossible for the gas to be discharged, which will also affect the oxygenation efficiency. Generally speaking, the suitable water depth for the rotational flow aerator is between 3-6 meters.