The Difference Between MBR and MBBR in Sewage Treatment

Distinguish by definition

• MBR:Membrane bio reactor
• MBBR:Moving Bed Biofilm Reactor

Distinguish by principle

• MBR:Activated sludge & membrane separation
• MBBR:Biofilm

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.

Difference between mbr vs mbbr

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 such as ceramic membrane module, flat sheet membrane module and spiral wound 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.

How to choose between mbr vs mbbr?

When deciding between MBR (Membrane Bioreactor) and MBBR (Moving Bed Biofilm Reactor) for a wastewater treatment system, there are several factors to consider. Both technologies have their advantages and disadvantages, so it's important to evaluate your specific requirements and conditions. Here are some key points to help you make a decision:

1. Treatment Efficiency:MBR systems generally offer higher treatment efficiency compared to MBBR systems. The membrane filtration in MBR prevents the passage of solid particles and microorganisms, resulting in a higher quality effluent. MBBR systems rely on biofilm growth on floating media for treatment, which may not provide the same level of filtration.

2. 
   Footprint and Space Requirements:MBR systems typically require a smaller footprint compared to MBBR systems. The membranes used in MBR systems allow for higher biomass concentrations, reducing the reactor size. MBBR systems require larger tanks to accommodate the floating media and provide sufficient contact time for biological processes.

3. 
   Operational and Maintenance Considerations:MBR systems require regular membrane cleaning and replacement, which can be a costly and time-consuming process. On the other hand, MBBR systems have lower maintenance requirements since they do not involve membranes. However, MBBR systems may require occasional replacement of the floating media.

4. 
   Tolerance to Shock Loads:MBR systems are generally more sensitive to shock loads, such as sudden increases in organic or hydraulic loads. MBBR systems are more resilient and can handle fluctuations in wastewater characteristics more effectively due to the biofilm's ability to adapt and recover quickly.

5. 
   Energy Consumption:MBBR systems typically require less energy compared to MBR systems because they do not involve membrane filtration. MBR systems require energy for maintaining the required pressure to overcome the membrane's resistance.

6. 
   Capital and Operating Costs:MBR systems are generally more expensive to install and operate due to the costs associated with membrane technology. MBBR systems tend to have lower capital and operating costs, making them more cost-effective for certain applications.

Ultimately, the choice between MBR and MBBR depends on the specific requirements of your wastewater treatment project, such as effluent quality standards, available space, budget, and the ability to handle shock loads. It is recommended to consult with wastewater treatment experts or engineering consultants who can evaluate your needs and help you make an informed decision.