Heaven says three very "foreign" crafts, right? Just like Xiaocui became Marry, does it look more foreign to put on a foreign name?

Today, these three heroes are SBR, MBR and MBBR, but the foreign spirit is enough. For our native Chinese, looking at foreign names is like looking at foreigners, and we feel that everyone looks the same. We can't tell who Zhang San is and who Li Si is, especially for these college graduates For newcomers to the hydrosphere: "Well done 'sequencing batch bioreactor', 'membrane bioreactor', 'mobile bed extracellular matrix tubular reactor', what kind of SBR, MBR, MBBR must be engaged in"! Do you think of your own appearance when you were young? Have you ever experienced such complaints?

In fact, for the environmental water treatment manufacturing industry, due to the various types of sewage collected, the water flow of the water body is also different, so compared with water supply and drainage solutions, there are many processes, long steps, and with the continuous efforts of scientific and technological personnel, a large number of technologies have emerged in endlessly. Therefore, for environmental water treatment practitioners, appropriate learning and training should be conducted, It is very important to ensure that you are not out of date.

Now let's summarize SBR, MBR and MBBR, and see if the difference between the surface and the inside is a thousand miles away.

01 Sequence approval bioreactor (SBR)

SBR is called sequencing batch reactor activated sludge process in Chinese and sequencing batch reactor activated sludge process in English. It looks very obscure, but you just need to remember its abbreviation "SBR".

SBR process is an activated sludge process operated according to the method of intermittent hydrolysis acidification tank. The key to SBR technology is the SBR reaction tank, which integrates homogenization, primary sedimentation, degradation, secondary sedimentation, etc. into one tank. In the same reaction tank (reactor), it is composed of five basic processes, namely, water seepage, reflection, sedimentation, drainage pipeline and shutdown in sequence. There is no sludge flowing back to the system software, and the whole process of anaerobic (lack of) aerobic will be generated in the tank, Therefore, it has a very good practical effect of nitrogen and phosphorus removal. Especially in places where intermittent sewage discharge is applicable and the total flow changes greatly, decanter is a main equipment of this method.

Schematic diagram of SBR core equipment decanter principle

The SBR process does not need to set up a regulating tank, and the sludge volume index (SVI) value is low, so the sludge is easy to settle and is not easy to produce sludge bulking; Especially in recent years, with the improvement of automation management level, electric valves, level gauges, automatic timers, programmable controllers and other automatic control instruments are widely used, which makes the whole process of SBR process automated. When the operation management is correct, the effluent quality can be better than that of continuous activated sludge process. Compared with other methods, SBR also has the advantages of small floor area The ability to withstand shock loads and to treat toxic or high concentration organic wastewater.

Five stages of SBR reaction (intermittent reaction)

02 Membrane MBR membrane Bioreactor (MBR)

MBR is a new high efficiency wastewater treatment process that combines high efficiency membrane separation equipment with traditional activated sludge process. MBR membrane parts are used to replace the traditional secondary sedimentation tank. The solved water is removed by the pump according to membrane spinning, while the activated sludge is intercepted by membrane separation technology, which is not easy to be discharged out of the system software, In turn, the activated sludge age is greatly increased, and the activated sludge concentration value is increased. Its major characteristic is to complete the separation of sludge retention time (SRT) and hydraulic retention time (HRT).

Common MBR solution to municipal wastewater production process

The most critical component of MBR process is the membrane component, which is divided into membrane, tubular membrane, chamber filter press type (flat built-in) membrane, roll type membrane and capillary type membrane. Its effect is equal to the secondary sedimentation tank in traditional biological aerated filter. The filtration precision of membrane component is high, and it can generally intercept 0.01 μ m～0.1 μ M Solid state.

Of course, MBR membrane must also consider the softener after long-term operation, and when the actual effect of physical cleaning method is not very good, chemical cleaning must be carried out, which can make the membrane flux repair better. Common chemicals include acid solution, caustic soda solution, antioxidant, reducing agent, enzyme, surfactant, etc. Although organic chemistry can produce pollutants, it will also introduce new pollutants, and chemical cleaning drugs have certain damaging effects on microbial strains, so the actual operation standards and methods must be paid attention to.

MBR process flow (normal operation+backwashing)

03 Moving bed biofilm reactor (MBBR)

MBBR is a new type of biofilm reactor, which is an improved new type of composite biofilm reactor based on the basic development trend of fixed bed reactor, fluidized bed reactor and biofilter. It gets rid of the fixed bed reactor, which must be backwashed on time, and the fluidized bed reactor must fluidize the media, The complicated practical operation of cleaning filter materials and replacing mechanical filters is not enough for the plugging of the submerged biofilter, and the characteristics of the traditional biofilm method, such as impact load resistance, low sludge production and long sludge age, are preserved. The key of MBBR depends on a kind of unique filler, whose relative density is ≈ 1, which is similar to the density of water. Therefore, fluidization can be completed without great driving force.

MBBR process filler (relative density equal to 1)

The key basic principle of MBBR is that after the wastewater continuously flows through the filler medium of the tubular reactor, biofilm will be generated on the medium, and many microbial strains will breed, in addition, organic chemical air pollutants will be dissolved. Compared with activated sludge process, MBBR process can maintain more photosynthetic bacteria due to its longer sludge age, and has stronger actual nitrogen removal effect.

MBBR can set a secondary sedimentation tank or not. If it does not set a secondary sedimentation tank, it is pure MBBR technology and classified in the scope of biofilm process. If it sets a secondary sedimentation tank, it is called mixed teaching MBBR system software. In addition, it takes into account the technological characteristics of biofilm and activated sludge process.

MBBR process unit and operation

04 Summary

Finally, the characteristics and differences of the three processes are summarized as follows:

1. SBR belongs to an intermittent activated sludge process, which is divided into five links: water seepage, reflection, settling, drainage pipeline and shutdown. The key component is the decanter;

2. MBR belongs to a new type of activated sludge process, which does not set a secondary sedimentation tank, but uses membrane to intercept the sludge in the tubular reactor. Note that the membrane here is not biological membrane, but microfiltration or Dow reverse osmosis membrane;

3. MBBR belongs to a biofilm process (note that the membrane here refers to the biofilm). The process features the application of a filler similar to water density, which can collect dust without a very large driving force, and can set a secondary sedimentation tank or operate independently without setting a secondary sedimentation tank.