In common : Activated sludge &membrane separation
At present, repeated water quality often occurs in river water treatment projects. The fundamental reason is that they have not strictly followed the governance ideas of "Source control and pollution interception, endogenous governance, dredging of running water, ecological restoration, and long-term management". However, the most important part of these five steps, "source control and pollution interception" is not a one-day effort. Whether it is to improve the treatment capacity of the sewage treatment plant or to realize the separation of rain and sewage in the true sense, it will take several years to achieve. At this time, integrated equipment with point source pollution control and long-term operation capabilities has become a good solution.
There are many types of integrated equipment in the secondary processing part: A2/O series, SBR series, BAF series, etc. This article analyzes the two most easily confused processes currently promoted in the market: MBR and MBBR.
The full name of MBR is membrane-bioreactor, which is an improved process of activated sludge method. The core principle is to replace the secondary settling tank with MBR membrane to reduce the floor space and sludge volume. It needs to be used in combination with microorganisms.
The full name of MBBR is a moving bed biofilm reactor, which is an improved process of the biofilm method. The core principle is to increase the unit microorganism content in the reactor by using the membrane as a carrier to improve the treatment efficiency.
Practical Application
MBR can effectively improve sludge load, while MBBR belongs to biofilm process, both of which have good effect on organic pollutant treatment, including COD, BOD and ammonia nitrogen.
MBR has obvious effects in treating SS, but it is a problem that it is easy to block the membrane. MBBR does not have the ability to treat SS, and needs to be combined with later coagulation sedimentation or UF treatment.
In actual cases, there are common standards for effluent indicators such as Category IV and Category V, and the word "Class" is prepared for TN and TP that are difficult to remove.
MBR does not have any TN processing capabilities. MMBR can treat TN through denitrification due to the existence of hypoxic areas in the biofilm.
With the exception of TP, MBR, like MBBR, does not have processing capabilities and requires chemical phosphorus removal.
Cost Comparison
The initial investment of MBR is relatively low, but the average life of membrane module is within 5 years, and they need to be replaced when they expire. Moreover, due to serious membrane blockage, they must be cleaned on demand during daily operation, and the operation and maintenance costs are relatively high.
The initial investment of MBBR is high, and only a small amount of management is needed after successful biofilm formation, so the operation and maintenance cost is very low.
Other Factors
MBR biology starts quickly and has quick results. The MBBR bio-filming period may take more than 3 weeks, and the debugging period is longer.
There is no question of whether MBR and MBBR are better or worse. They need to be selected and matched flexibly according to the application scenario.
The difference between MBR and MBBR is shown as below table.
| Item | MBBR | MBR | Common | Difference |
| Definition | Moving bed biofilm reactor | Membrane bio reactor | No | Biofilm & membrane |
| Principle | Biofilm process | Activated sludge & membrane separation | Rely on activated sludge to remove organic matter | No |
| Effluent quality | In addition to TP and SS, it can meet the requirements of four types of water bodies | In addition to TP , it can meet the requirements of four types of water bodies | Rely on chemical process to remove phosphorus | MMBR cannot remove SS alone |
| Daily operation management | Simple | More difficult | No | MBBR packing does not need to be replaced, and the MBR membrane module needs to be replaced once every 5 years |
| Cost | The initial investment is large, and the later operation is small | The initial investment is large, and the later operation islarge | The initial investment is large | The cost of MBR component replacement is high |