Environmental protection engineering test center: biological moving bed

20 17 environmental engineering test site: biological moving bed

Biological moving bed (MBP), also known as moving bed biofilm reactor, is a new and efficient biofilm wastewater treatment device developed on the basis of biological contact oxidation and biological fluidized bed in recent years. The following are the knowledge points about biological moving bed.

function

It not only has the characteristics of traditional biofilm process, such as impact load resistance, long sludge age and less excess sludge, but also has the characteristics of high efficiency and flexible operation of activated sludge process. It is developed to solve the complex operations such as periodic backwashing of fixed bed bioreactor, carrier fluidization of fluidized bed, easy blockage of submerged biofilter, cleaning filter material and replacing aeration head, and is suitable for the treatment of small and medium-sized domestic sewage and industrial organic wastewater.

(1) basic process flow

After the sewage is treated in the primary sedimentation tank, it enters the biological moving bed reactor, and the treated water flows out from the overflow port with grid net above the reactor and enters the secondary sedimentation tank for mud-water separation.

⑵ Composition of biological moving bed reactor

The biological moving bed reactor is mainly composed of tank, carrier, water outlet device, aeration system or stirring system.

① Pool body

Made of steel or reinforced concrete, round or rectangular. In application, the existing activated sludge tank or other wastewater tanks can be used for transformation, so this process is more suitable for the transformation of sewage plants.

② Carrier (filler)

The density of carriers is slightly less than 1, and these floating carriers move freely with the rotation and turnover of mixed liquid in the reactor. At present, most of the fillers used in moving bed biofilm reactors are polyethylene and polypropylene plastics. The density is generally about 0.96g/cm3, and the volume surface area of the filler is relatively large, which can reach 200 ~ 500m2/m3.

③ Water outlet device

The effluent device requires that the carrier be trapped in the reactor and not blocked by effluent biofilm or activated sludge. The aperture of the water outlet device depends on the appearance size of the biological filler.

④ Ventilation or mixing system

Generally, small and medium-sized aeration pipes are used, and uniform gas distribution is required. Aeration can realize the dual functions of oxygen supply and fluidization.

⑶ Main technological characteristics of biological moving bed reactor

① The reaction speed is fast.

(2) The head loss is small, it is not easy to be blocked, and it does not need backwashing, generally it does not need backflow.

③ It is convenient to upgrade the sewage treatment plant.

④ The system is easy to control and manage.

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