Everything you need to know about the MBBR functions

A moving bed biofilm reactor, or MBBR, is a version of an activated sludge system. However, wastewater treatment using a moving bed biofilm reactor is one of the most common biological treatment methods and is used for good reasons. For example, it is compact and has a smaller footprint compared to other methods. It is a relatively simple process that involves fewer steps, requires less maintenance, and is also very effective. In this article, you will find out more about the MBBR functions and how they work.

How does a moving bed biofilm reactor work?

The reactor is filled with thousands of biofilm carriers (plastic pieces) that protect the bacteria used to break down pollutants in the wastewater. A diffuser grid produces the air needed to effectively distribute the biofilm carriers throughout the tank, while also providing the necessary aeration for the biofilm to grow.

There are four different components within a moving bed biofilm reactor system: the plate stack, the air diffusers, the carriers, and the biofilm.

The wastewater treatment process takes place inside an aeration tank.

The media consists of thousands of small plastic flakes that, due to their density, can completely mix the wastewater.

The aeration grid is like a fan; it helps keep the media moving through the wastewater while introducing oxygen into the aeration tank.

Finally, the biofilm is a piece of equipment that prevents the media from leaving the aeration tank.

MBBR Equipment Components

Laminate Package:

Laminate units increase the specific contact surface area which results in a higher separation rate of suspended particles, thus accelerating the sedimentation process, creating a higher TSS separation capacity, a larger surface area per square meter, and better UV resistance.

Air Distributors:

Wideband air distributors work by creating an air reservoir that allows air to pass freely through it. With the help of the deflector plate located at the bottom of the system, the distributor prevents debris and sediment from entering or obstructing the functions of the device. The corrosion resistance and flexibility of this distributor help provide balanced air distribution to all piping systems.

Carriers:

The MBBR process is based on the activity of microorganisms that attach to and grow on a large surface of porous solids called floating carriers in the wastewater medium. The main role of the carriers is to provide a protected surface for the growth of “biofilms”. Carriers, which have a density close to that of water, float and circulate freely in the wastewater through aeration bubbles (in aerobic chambers) or mechanical mixing (in anaerobic chambers).

Biofilms:

Complex colony structures consist of microorganisms and the biomaterials they secrete.

MBBR System Distributors

The air injection system is highly efficient with wide-band bubble distributors made of high-quality stainless steel and fixed to a PVC air distribution network. Air is generated by side-channel blowers with a capacity of 150 m3/h at 0.3 bar.

A simple video explaining how the moving bed biofilm works

The main advantages of our MBBR system

• Reduced space required for installation.
• Simple operation without the need for sludge recirculation or control of cell residence time.
• Elimination of clumping problems in the secondary clarifier and their impact on the quality of the pollutants.
• Ability to withstand extreme loads and flow changes.
• It is a continuous operating system that does not require constant attention or interruption of treatment.

Operation of the moving bed biofilm reactor

As mentioned earlier, this process is an activated sludge system in which a floating polyethylene material is introduced to support the growth of biomass on its surface. This floating material provides an effective surface area for the growth of biofilms, which increases the effective volumetric concentration of biomass.

This type of forced biomass growth on a floating element has a number of special characteristics:

The MLSS concentration (biomass concentration inside the reactor) can be 1.5 to 2 times higher than the concentration achieved using conventional activated sludge systems and can reach 4000 – 8000 mg / l.

The effective cell residence time is increased.

The treatment capacity of the system is increased for the same volume.

Since the increase in MLSS is due to the growth adhering to the carriers, there is no increase in the concentration of sludge reaching the secondary clarification, but rather it is reduced, and therefore the dimensions of this clarification are smaller than those of conventional systems.

MBBR System Applications

The applications of MBBR systems vary from water care institutions, from industrial wastewater to more specialized applications, these systems are preferred when space requirements are very small and maximum simplicity of operation is required.

• Industrial processes.
• Municipal water.
• Military camps and humanitarian missions.
• Hotels and resorts.
• Buildings: hospitals, shopping malls, etc.

Learn more about the applications where MBBR for wastewater should be used

MBBR reactor efficiency

What makes moving bed biofilm reactors a unique process? All the microorganisms are needed to remove the pollutant load. They are immersed in the reactor attached to the plastic carriers. Thanks to this system, the only biomass that needs to be removed from the system is that which has been separated from the carriers and that which is suspended in the already treated wastewater.

The MBBR system relies on the activity of microorganisms that attach and grow on large porous solids called “carriers”, which float in the wastewater medium. The primary role of the carriers is to provide a protected surface for the growth of “biofilms”.

By “biofilms” we mean complex colony structures composed of microorganisms and the biological materials they secrete.

The carriers, which have a density close to that of water, float and rotate freely inside the reactor by means of aeration bubbles (in aerobic chambers) or mechanical mixing (in anaerobic chambers).

The rotation of the carriers in the water regulates and stabilizes the growth of the biofilm and the kinetics of the reaction.

After the reactor, this biomass can be separated by a plate clarifier, resulting in clean waste. This way we ensure that the reactor always retains the microorganisms necessary for its operation it, ensuring the efficiency and performance of this treatment system.

Comparison of some types of water treatment technologies with MBBR

Activated Sludge Process vs. MBBR

Activated Sludge Process (ASP) shares some similarities with MBBR. In this traditional process, wastewater enters an aeration tank containing high levels of oxygen. This oxygen helps in the process of microbial growth and the decomposition of organic waste. The water then moves to a sedimentation tank. That the remaining waste in the water separates from the water, leaving it cleaner.

The activated sludge process is a tried and true method of biologically treating wastewater. However, research has shown that under optimal conditions. MBBR can remove chemical oxygen demand more effectively and can handle organic loading more effectively than ASP. MBBR takes advantage of the same strengths as ASP and offers additional benefits that make it a superior technology.

Drip Filtration Process vs. MBBR

Drip filtration is another popular treatment. This process uses a layer of material, such as gravel, rock, ceramic, or plastic, to retain microorganisms in the water as they pass over the layer of material. These microorganisms will create a biofilm over time, which will then decompose the organic matter in the wastewater. Periodic oxygenation can make the environment more aerobic.

This process cannot compete with MBBR when it comes to efficiency or ease of operation. In the case of drip filtration processes, a skilled operator must closely monitor the process. Clogs are a common problem with this process, but they rarely occur with MBBR.