The traditional activated sludge treatment method is one of the oldest industrial sewage treatment processes, and the key components of industrial sewage treatment are biogas digesters and sedimentation tanks. The relationship block diagram of the main processing part is as shown in the figure.

When the organic matter in the sewage stays in the aeration tank, the microorganisms in the aeration tank absorb most of the organic matter in the sewage and are oxidized into inorganic matter in the aeration tank, and then part of the activated sludge precipitated in the sedimentation tank needs to flow back to the aeration tank. The advantages of this process are high organic matter removal rate, high sludge load, small tank volume, low energy consumption and low operating cost. The disadvantages of this process are: the common aeration tank occupies a lot of land, the construction investment is large, the range of relevant indexes meeting the national standards is small, sludge bulking is easy to occur, and the removal rate of phosphorus and nitrogen is low.

Sewage treatment equipment

2.A2/O method

A2/O process is also an industrial sewage treatment process developed on the basis of traditional activated sludge process, in which A2 is A-A, the former A stands for anaerobic (anaerobic) and the latter A stands for anoxia (anoxia); O stands for (aerobic). A2/O is an anaerobic-anoxic-aerobic industrial wastewater treatment process. The effect of A2O process on phosphorus and nitrogen removal is very good, which is very suitable for industrial wastewater treatment that needs phosphorus and nitrogen removal. Therefore, A2/O process is generally the first choice for urban industrial sewage treatment plants with special requirements for phosphorus and nitrogen removal. The process flow is shown in the figure.