The basis for regulating dissolved oxygen in aeration tanks!

In the process of activated sludge treatment, adjusting the gas volume of the aeration tank is an important part of ensuring the stable operation of the system and the water quality standard. Here's how to adjust the gas volume:

1. Adjust according to dissolved oxygen (DO) concentration
       The dissolved oxygen concentration at the outlet of the aeration tank should be controlled at 2-4 mg/L. If the dissolved oxygen concentration is too low, the gas volume needs to be increased; If it is too high, reduce the gas volume appropriately.
       The DO concentration can be monitored in real time by means of a dissolved oxygen sensor and the air volume of the blower can be automatically adjusted according to the set target value.

2. Adjust according to water quality and process requirements

Adjust the gas volume reasonably according to the influent water quality (such as COD, BOD concentration) and treatment process (such as A/O, A2/O, etc.). For example, high concentrations of organic wastewater may require higher aeration rates.

For low temperature environment or large fluctuations in water quality, increase the gas volume appropriately to ensure the treatment effect.

3. Adjust by aeration equipment

Regulating valve: Adjust the air intake through the butterfly valves on both sides of the air duct to ensure that the mixed liquid in the pool is fully aerated.

Adjust the aeration operation time: Increase or decrease the aeration operation time to adjust the aeration volume.

Check the installation level of the aeration head: Make sure that the aeration head is installed on a horizontal plane to avoid uneven aeration due to installation errors.
      4. Adjustments based on empirical formulas or calculation methods
Calculation by air-water ratio: Determine the air-water ratio (e.g., 10:1 or 15:1) according to the type of aeration tank (e.g., contact oxidation tank, activated sludge tank), and calculate the required gas volume accordingly.
Calculation according to the aeration intensity per unit pool area: usually the aeration intensity of 10-20 m³/m²·h is usually taken, and the required air volume is calculated according to the area of the pool.

5. Adjust based on operating data

Regularly test the sludge sedimentation ratio, activated sludge status, supernatant transparency and other indicators in the aeration tank, and adjust the gas volume according to the data.

The dissolved oxygen, temperature, and sedimentation ratio of the mixture are measured every 2 hours, and the air intake is adjusted according to the measurement results.

6. Adopt a precise aeration system

Using a precise aeration system based on a multi-parameter control mode based on "feedforward model feedback", the required aeration volume is calculated in real time and the dissolved oxygen is finely controlled by adjusting the air volume of the blower.

Through the above methods, the gas volume of the aeration tank can be effectively adjusted to ensure the stable operation of the aeration tank and the water quality standard.