How does MBBR technology work in the treatment of industrial wastewater?

Managing wastewater is a challenge for all industries , but especially for those that generate water with a high organic load or with contaminants that require specialized treatment.

Moving bed biofilm reactors, known as MBBR (Moving Bed Biofilm Reactor) systems , are a solution full of advantages due to their ability to treat a large amount of water.

We explain what MBBR technology is and how it works 

Are you interested in learning more about MBBR technology and how this innovative and efficient wastewater treatment solution works?

At SITRA, we answer your questions. 

What is an MBBR system?: definition and components 

MBBR is an advanced biological process for wastewater treatment.

This technology, developed in the late 80s, is based on the use of microorganisms for the treatment of industrial wastewater. The MBBR system can operate under both aerobic and biomass conditions , using small, movable polyethylene and polypropylene supports on which a biofilm grows, degrading the water's contaminants.

Unlike activated sludge, where microorganisms are suspended in water, the high-density plastic supports of MBBR systems have very varied sizes and geometric shapes to maximize the surface area and generate a higher concentration of active biomass inside.

These supports are kept in suspension and in constant motion to ensure contact between biofilm and water contaminants, and to guarantee constant oxygen renewal.

The reactor also has a grid or sieve that retains the carriers inside the tank , so that only the treated water and excess biomass that has detached from the carriers leave the reactor.

In this way, the reactor effluent is taken to a secondary clarifier ( such as a decanter or a DAF floater, for example) to separate the treated water from the excess sludge.

In summary, the components of an MBBR system are:

1. Biological reactor or tank
2. Mobile supports (carriers or carriers)
3. aeration system
4. Grid or support retention system
5. Sicontrol and monitoring systems
6. Pretreatment elements (screens, grit chambers or primary sedimentation tanks) and post treatment (complementary units such as clarifiers, filters or disinfectants).  

If you'd like to learn more about how industrial wastewater treatment plants work and how they integrate with systems like MBBR, you can read our article on ➡️ How does an industrial wastewater treatment plant work?

MBBR Objectives and How It Works 

MBBR systems are designed to remove organic and inorganic contaminants present in industrial wastewater more efficiently and sustainably.

To better understand what MBBR is and how it works, we need to explain the entire water treatment process.

This can be divided into 5 phases: 

1. Wastewater conditioning

Before entering the MBBR reactor, the wastewater goes through a pretreatment that generally includes screening to remove coarse solids, screening for fine solids, and, if necessary, a degreasing process (using static separators or CAF floaters) if the water contains oils and greases.

Furthermore, if the water contains suspended solids, a physical-chemical treatment can be applied. The design of the pretreatment depends on the characteristics of the water, and although it is not always necessary, it is installed to ensure the protection and efficiency of the system.

2. Introduction of supports

The MBBR tank is filled with plastic supports that can occupy between 20% and 70% of its total volume depending on the type of contaminants present in the water, the organic load of the water, or the objective of the treatment.

3. Biofilm development and contaminant degradation 

When wastewater comes into contact with the tank supports, microorganisms (present in the water or inoculated) adhere to its surface, growing to form an increasingly mature and active biofilm.

The goal is for this microbial film to consume organic matter and other water pollutants, such as nitrogen and phosphorus. 

4. Movement of the supports

Oxygen transfer is crucial in aerobic reactors, as this component maintains microbial activity in the tank.

Therefore, the MBBR supports must be kept in motion, either through an aeration system or mechanical agitation . In anoxic MBBR systems, only mechanical agitation is used, as aeration is not required.

This movement also eliminates potential excess biomass in the carriers, helping to maintain the balance and cleanliness of the entire system.

5. Effluent separation

Finally, the contaminant-free water and the sludge detached from the biofilm flow into a new solid-liquid separation phase.

This process permanently removes suspended particles, resulting in a higher quality effluent. This process can be carried out through sedimentation (such as in a settling tank) or by using a DAF (Dissolved Air Flotation) unit , for example.

It is important to note that the reactor effluent is not just clean water, but clean water mixed with excess biomass. Therefore, it is necessary to separate the biomass from the effluent afterward.

Advantages of an MBBR compared to other wastewater treatments 

Moving bed bioreactors have many benefits, including: 

• High capacity. These systems can treat large quantities of wastewater, with a high organic load, in a small space thanks to the high concentration of active biomass in their mobile plastic supports. 
• Stability. The biofilm is stable and resilient to fluctuations in the quality and volume of wastewater. 
• Low maintenance. An MBBR reactor requires little maintenance. Furthermore, the supports have a fairly long lifespan.
• Resistance. The MBBR biofilm helps to isolate microorganisms, allowing this process to be effective even in outdoor facilities and at low temperatures. 
• Adaptability. MBBR tanks are configured to remove varying amounts of organic load, nitrify, or denitrify. This allows them to be adapted to different industries and applications. 

Comparison of industrial wastewater treatments: which is more efficient? 

Efficiency in industrial wastewater treatment is key to complying with regulations and reducing costs. Several methods exist, and the choice depends on factors such as the type of industry and the volume of water to be treated.

MBBR vs. conventional activated sludge (CAS)

MBBR systems are more compact than CAS systems, but they still require aeration and secondary clarifiers. This is because, unlike MBBRs, MBR (membrane bioreactor) systems do not need secondary clarifiers.

Furthermore, the MBBR is more resistant to load variations and toxic residues , making it especially useful in the agri-food industry, a sector where there are many differences in consumption, volume and wastewater load.

MBBR is also easier to maintain and clean than activated sludge, as it does not require strict sediment control and produces less sludge.

MBBR vs. membrane bioreactors (MBR)

Although MBRs offer slightly superior effluent quality by using physical barriers to remove almost all suspended solids and pathogens, with an MBBR there is no need to clean or maintain the membranes.

MBBR vs. fixed beds or biotrickling filters (BTF)

Using fixed beds can obstruct microbial biofilm growth , making the system less efficient.

In addition, using BTFs requires investing time and money in cleaning the supports.

When is an MBBR system recommended? Uses and expert advice 

MBBR systems have many applications for wastewater treatment in various industries.

In the case of the food industry, where they are more common, their main use is the treatment of effluents with a high organic load from food, beverage, dairy processing plants, etc.

However, these types of reactors can also be used successfully:

• In the paper industry. To remove organic matter and colors from effluents derived from paper and pulp production.
• In the textile industry. To bleach water and remove traces of organic matter from dyeing and finishing.
• In the chemical and petrochemical industry. To treat wastewater containing complex organic compounds that are resistant to degradation.

To better understand how proper wastewater treatment positively impacts the environment, don't miss our article on ➡️ Environmental impact of industrial wastewater: causes, consequences and solutions.

Do MBBRs serve as a support system for activated sludge installations? 

Yes. In fact, MBBRs are a solution for increasing the capacity of activated sludge plants and improving the performance of large water treatment plants without having to build new tanks.

How can SITRA help you? 

MBBR systems are compact, guarantee operational stability, facilitate maintenance, and represent a low investment compared to other systems, such as activated sludge. 

What is an MBBR system? It's an innovative and efficient wastewater treatment solution, ideal for industries like agribusiness. At SITRA, we help you implement this advanced technology, optimizing water treatment in a cost-effective and sustainable way.

In fact, they are an alternative with great potential and one that our clients are increasingly valuing more positively.

At SITRA we are experts in aerobic technology and MBBR system installation, and we design and build facilities for the treatment of industrial wastewater under the highest quality standards.

We work with the most innovative and high-potential technologies on the market, and we guarantee customized solutions based on your needs.

📞 Contact us.