QDEVU® Intergated A/O Sewage Treatment Plant

QDEVU Integrated Sewage Treatment Plant is mainly for the treatment of domestic sewage and industrial organic wastewater.

QDEVU Anoxic/Oxic (A/O) Integrated Sewage treatment Plant, which integrates anaerobic tank, facultative tank, aerobic tank, sedimentation tank, disinfection tank and sludge tank, and is a high-efficiency sewage treatment equipment integrating the removal of BOD5, COD and NH3-N. The contact oxidation method and the activated sludge method can be effectively combined, and the advantages of both methods can be achieved. The disadvantages of both methods can be overcome, and the sewage treatment level can be further improved.

WORKING PRINCIPLE

A/O is the abbreviation of Anoxic/Oxic. Its advantage is that it not only degrades organic pollutants, but also has certain nitrogen and phosphorus removal functions. It uses anaerobic hydrolysis technology as the pretreatment of activated sludge, so A/O method is an improved activated sludge method.

In the A/O process, the anoxic section in the front section and the aerobic section in the back section are connected in series. The DO in section A is not greater than 0.2mg/L, and the DO in section O is 2 ～ 4mg/L. In anoxic section, heterotrophic bacteria hydrolyze suspended pollutants such as starch, fiber, carbohydrate and soluble organic matter in sewage into organic acid, so that macromolecular organic matter can be decomposed into small molecule organic matter, and insoluble organic matter can be converted into soluble organic matter. When these products are hydrolyzed under anoxic conditions into aerobic tanks for aerobic treatment, the biodegradability of sewage and the efficiency of oxygen can be improved; In the anoxic section, the heterotrophic bacteria ammonifies pollutants such as protein and fat (N on the organic chain or amino acid in the amino acid) to free ammonia (NH3, NH4+). Under sufficient oxygen supply, the nitrification of the autotrophic bacteria oxidizes NH3-N (NH4+) to HO3 -, and returns to pool A through reflux control. Under anoxic conditions, the denitrification of the heterotrophic bacteria reduces NO3 - to molecular nitrogen (N2) to complete the cycle of C, N, and O in the ecology, Realize harmless treatment of sewage.

PROCESS FEATURE

• Before the anoxic tank, the organic carbon in the sewage is used by the denitrifying bacteria, which can reduce the organic load of the subsequent aerobic tank. The reduction caused by denitrification can compensate the demand for alkalinity for nitrification in the aerobic tank.
• After the anoxic tank, aerobic can further remove the residual organic pollutants in denitrification and improve the effluent quality.
• The removal rate of BOD5 is higher than 90~95%, but the effect of nitrogen and phosphorus removal is slightly poor. The nitrogen removal efficiency is 70~80%, and the phosphorus removal efficiency is only 20~30%. However, due to its simplicity and outstanding characteristics, A/O process is still widely used. The process can also combine anoxic tank and aerobic tank, with baffle plate in the middle to reduce the project cost, so this form is conducive to the transformation of the existing push flow aeration tank.