Briefly describe a sewage treatment process

The flow of membrane biological treatment technology (MBR) sewage treatment process:

Raw water → grill → regulating pool → lifting pump → bioreactor → circulation pump → membrane module → disinfection device →Reclaimed water storage tank→Reclaimed water water system

Sewage enters the regulating tank through the grille and then enters the bioreactor through the lifting pump. The aerator is turned on through the PLC controller for oxygenation, and the bioreactor effluent is circulated The pump enters the membrane separation treatment unit, and the concentrated water returns to the regulating tank. After the membrane-separated water undergoes rapid mixing and chlorination disinfection (sodium hypochlorite, bleaching powder, chlorine tablets), it enters the gray water storage tank.

The backwash pump uses the treated water in the cleaning tank to backwash the membrane treatment equipment, and the backwash sewage returns to the regulating tank. The opening and closing of the lift pump is controlled by the water level in the bioreactor.

The filtration operation and backwash operation of the membrane unit can be controlled automatically or manually. When the membrane unit requires chemical cleaning operations, close the water inlet valve and sewage circulation valve, open the chemical washing valve and chemical circulation valve, start the chemical liquid circulation pump, and perform chemical cleaning operations.

Extended information

Membrane biological treatment technology is used in wastewater regeneration and has the following characteristics:

(1) It can efficiently separate solid-liquid , to separate suspended substances, colloidal substances, and microbial flora lost from biological units in wastewater from purified water. The separation process is simple, occupies a small area, and the effluent quality is good. Generally, it can be reused without tertiary treatment.

(2) The biomass in the biological treatment unit can be maintained at a high concentration, greatly increasing the volume load. At the same time, the high efficiency of membrane separation greatly shortens the hydraulic retention time of the treatment unit, and the bioreactor's The floor space is reduced accordingly.

(3) Since it can prevent the loss of various microbial flora, it is conducive to the growth of slow-growing bacteria (nitrifying bacteria, etc.), thereby allowing various metabolic processes in the system to proceed smoothly.

(4) Longer the residence time of some macromolecules that are difficult to degrade, which is beneficial to their decomposition.

〔5〕Membrane treatment technology is the same as other filtration and separation technologies. During long-term operation, the membrane, as a filter medium, becomes clogged, and the water volume of the membrane gradually decreases with the operation time. Effective backwashing and Chemical cleaning can slow down the decline of membrane flux and maintain the effective service life of the MBR system.

(6) MBR technology is used in urban sewage treatment. Due to its simple process and easy operation, it can achieve fully automatic operation and management.

Baidu Encyclopedia-Sewage Treatment Process