What are the types of aeration tanks? What are their conditions of use?

To date, in the field of activated sludge engineering, there are a variety of distinctive operating methods. There are mainly the following types: ① traditional push-flow activated sludge method; ② completely mixed activated sludge method; ③ stage aeration activated sludge method; ④ adsorption-regeneration activated sludge method; ⑤ delayed aeration activated sludge method; ⑥ high load activated sludge method; ⑦ pure oxygen aeration activated sludge method; ⑧ shallow low-pressure aeration activated sludge method; ⑨ deep-water aeration activated sludge method; ⑩ deep well aeration activated sludge method. Activated sludge method.

1, the traditional push-flow activated sludge method:

① process:

② oxygen supply and demand curve:

③ the main advantages: 1) good results: the removal rate of BOD5 can reach 90-95%; 2) the degree of flexibility of the treatment of wastewater, according to the requirements of the adjustment.

④ Main problems: 1) In order to avoid the formation of anaerobic state at the end of the pool, it is inappropriate to use too high an organic load, so the pool capacity is large and covers a large area; 2) at the end of the pool there may be a phenomenon that the rate of oxygen supply is higher than the rate of oxygen demand, which wastes the cost of power; 3) the adaptability to the impact of the load is weaker.

⑤ Generally adopted design parameters (treatment of municipal wastewater):

2. Complete mixed activated sludge method

① Main features: a. It can be conveniently adjusted through the F/M, so that the degradation of organic matter in the reactor is controlled in the optimal state; b. As soon as the influent enters the aeration tank, it is diluted by a large amount of mixing liquid, so it is resistant to the shock load; c. It is not possible to resist the shock load; d. It is not possible to control the oxygen supply rate at the end of the tank, which is higher than the oxygen demand rate; 3) It is weak to adapt to the shock load. resistance; c. Suitable for the treatment of higher concentrations of organic industrial wastewater.

② Main structural forms: a. Combined (aeration and sedimentation tank): b. Sub-built

3, stage aeration activated sludge method - also known as the segmented water intake activated sludge method or multi-point water intake activated sludge method

① process:

② Main features: a. Wastewater is injected into the aeration tank in sections along the length of the tank. Along the length of the pool segmented injection of aeration tank, organic load distribution is more balanced, improving the contradiction between the rate of supply and the rate of oxygen demand, is conducive to reducing energy consumption; b. Wastewater injection in segments to improve the adaptability of the aeration tank to the impact of the load;

③ Main design parameters:

4, adsorption regeneration activated sludge method - - also known as biological adsorption method or multi-point inlet activated sludge method

① Process flow. -Also known as biosorption method or contact stabilization method.