MBR portable single-machine treatment and purification system

In the field of sewage treatment and water reuse, MBR, also known as Membrane Bio-Reactor (Membrane Bio-Reactor), is a new type of water treatment technology that combines a membrane separation unit and a biological treatment unit. According to the structure of the membrane, it can be divided into flat membrane, tubular membrane and hollow fiber membrane. According to the membrane pore size, it can be divided into ultrafiltration membrane, microfiltration membrane, nanofiltration membrane, reverse osmosis membrane and so on.

Process type
According to the combination of membrane module and bioreactor, the membrane-bioreactor can be divided into three basic types: separate type, integrated type and composite type. (The following discussions are all solid-liquid separation membrane-bioreactors) [1]

Split
Separately set up the membrane module and the bioreactor. The mixed liquid in the bioreactor is pressurized by the circulating pump and hits to the filter end of the membrane module. Under the action of pressure, the liquid in the mixed liquid penetrates the membrane and becomes the system treatment water; solids and macromolecular substances are intercepted by the membrane. The concentrated liquid is returned to the bioreactor.
Separate membrane-bioreactor is characterized by stable and reliable operation, easy to clean, replace and add membrane; and the membrane flux is generally large. However, under general conditions, in order to reduce the deposition of pollutants on the membrane surface and prolong the cleaning cycle of the membrane, it is necessary to use a circulating pump to provide a higher cross-flow flow rate on the membrane surface. The water circulation volume is large and the power cost is high (Yamamoto, 1989). The shearing force generated by the high-speed rotation of the worm will inactivate certain microbial cells (Brockmann and Seyfried, 1997).

All-in-one
Place the membrane module inside the bioreactor. The influent water enters the membrane-bioreactor, where most of the pollutants are removed by the activated sludge in the mixed liquid, and then the water is filtered by the membrane under the action of external pressure.
This type of membrane-bioreactor has relatively low energy consumption due to the omission of the mixed liquid circulation system and the pumping of water; it occupies a more compact area than the separate type, and has attracted special attention in the field of water treatment. However, the general membrane flux is relatively low, which is prone to membrane fouling, and it is not easy to clean and replace the membrane after fouling.

Compound
It also belongs to the integrated membrane-bioreactor in form. The difference is that packing is added in the bioreactor to form a composite membrane-bioreactor, which changes certain characteristics of the reactor.

Process characteristics
Compared with many traditional biological water treatment processes, MBR has the following main advantages:
High quality and stable effluent water quality
Due to the efficient separation of membranes, the separation effect is much better than traditional sedimentation tanks, the treated effluent is extremely clear, suspended solids and turbidity are close to zero, bacteria and viruses are greatly removed, and the effluent quality is better than the domestic miscellaneous water quality standards issued by the Ministry of Construction (CJ25.1-89), it can be directly reused as non-potable municipal miscellaneous water.
At the same time, the membrane separation also enables the microorganisms to be completely intercepted in the bioreactor, so that the system can maintain a high concentration of microorganisms, which not only improves the overall removal efficiency of pollutants by the reactor, but also ensures good effluent water quality, while reacting The device has good adaptability to various changes in water inlet load (water quality and water volume), is resistant to impact loads, and can stably obtain high-quality outlet water quality.
Less surplus sludge output
The process can be operated under high volume load and low sludge load, and the remaining sludge output is low (theoretically, zero sludge discharge can be achieved), which reduces the cost of sludge treatment.
Small footprint, not restricted by setting occasions
The bioreactor can maintain a high concentration of microorganisms, the processing device has a high volume load, and the floor space is greatly saved; the process is simple, the structure is compact, and the floor space is saved. It is not restricted by the installation location, and is suitable for any occasion. It is ground, semi-underground and underground.
Can remove ammonia nitrogen and refractory organic matter
Since the microorganisms are completely trapped in the bioreactor, it is beneficial to the trapped growth of slow-proliferating microorganisms such as nitrifying bacteria, and the nitrification efficiency of the system is improved. At the same time, it can increase the hydraulic retention time of some refractory organics in the system, which is beneficial to improve the degradation efficiency of refractory organics.
Convenient operation and management, easy to realize automatic control
The process realizes the complete separation of the hydraulic retention time (HRT) and the sludge retention time (SRT), and the operation control is more flexible and stable. It is a new technology that is easy to realize equipment in sewage treatment, and can realize automatic control by microcomputer, thereby enabling operation management More convenient.
Easy to transform from traditional crafts
This process can be used as the advanced treatment unit of the traditional sewage treatment process, and it has broad application prospects in the field of advanced treatment of the effluent of the municipal secondary sewage treatment plant (thereby realizing the massive reuse of urban sewage).