Improved AAO wastewater treatment process for obtaining standard IV-class surface water

Abstract

The invention discloses an improved AAO wastewater treatment process for obtaining standard IV-class surface water. The process includes the following steps that wastewater is pretreated to remove suspended solids (SS) in the wastewater through precipitation; pretreated outlet water passes through an AAO biochemical tank, outlet water from the AAO biochemical tank enters a secondary sedimentation tank for solid-liquid separation, supernatant liquid discharged out of the secondary sedimentation tank enters a coagulation reaction tank, and outlet water enters a denitrification filter tank to further remove residual nitrate nitrogen; outlet water from the denitrification filter tank enters a disinfection tank, and after being disinfected, the water is drained. Biological nitrogen and phosphorus removal treatment is achieved through alternative circulation of the three different anaerobic-anoxic-aerobiotic parts of the AAO biochemical tank, and three anoxic parts and three aerobiotic parts are alternately arranged; by connecting anoxic tanks and aerobiotic tanks alternately in series, the arrangement of a mixed liquid return device is omitted; by adding an external carbon source into the third anoxic tank, the insufficiency of a denitrification carbon source can be supplemented; by arranging the third aerobiotic tank, residues of the external carbon source of the third anoxic tank can be consumed.

Description

technical field [0001] The invention belongs to the technical field of sewage treatment, and in particular relates to an improved AAO sewage treatment process for class IV surface water. Background technique [0002] With the increasingly prominent problem of water pollution in our country, the improvement of urban sewage treatment and discharge standards has become the general trend. Judging from the current requirements for improving the quality of the water environment, the effluent treated by many urban sewage treatment plants is often discharged into urban rivers and becomes the water body of the river. For the effluent of my country's existing sewage treatment plants, the discharge standards mostly refer to Class I A in the "GB18918-2002 Pollutant Discharge Standards for Urban Sewage Treatment Plants". However, for the first-class A standard, its water quality is only equivalent to the inferior V-class water of surface water. This kind of water is discharged into the...

AI Technical Summary

Problems solved by technology

This kind of water quality is discharged into the water body environment with little self-purification ability, resulting in the water body not only not being repaired, but polluted instead, so the phenomenon of "the more it is treated, the more dirty it is" appears

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