Common Misconceptions About MBBR Reactors

In the field of wastewater treatment, MBBR (Moving Bed Biofilm Reactor) is gradually emerging as an alternative to traditional methods such as activated sludge or trickling filters. With its perforated structure, biofilm on the surface, and flowing operation mode, MBBR media can introduce specific microorganisms into the wastewater to decompose the organic matter in it.

However, like many advanced technologies, there are quite a few misconceptions about MBBR reactors, which prevent people from trying this technology. We will discuss some of the possible misconceptions about them in the following text. After reading this article, you will have a better understanding of MBBR and be able to decide whether to adopt this technology in your water treatment project.

Many people assume without thinking that MBBR is vulnerable in the face of water quality shocks. But is that really the case? It should be noted that the biofilm at the core of MBBR is not just a simple aggregation of microorganisms. It is an ecological community constructed by different microorganisms. These microorganisms have gone through a long period of adaptation and have already evolved high adaptability. Once they detect a sharp increase in the concentration of organic pollutants in the wastewater, they will convert the excess organic pollutants into the energy and substances needed for their own growth.

Among them, the microorganisms on the outer layer of the biofilm deal with the easily degradable pollutants first, while the microorganisms on the inner layer are specialized in dealing with the more difficult pollutants. Under the impact of water quality, the inner-layer microorganisms that were originally on standby also get involved in the decomposition of pollutants instead of being quickly washed away. And this gives the MBBR media a very high resistance to water quality shocks.

Some people think that MBBR is only suitable for common types of wastewater such as domestic sewage and industrial wastewater. In fact, this is not the case. MBBR can handle a variety of wastewater types. Let's take the example of treating nitrogen-containing wastewater to explain further. The biofilm on the surface of MBBR contains a wide variety of microorganisms, including various aerobic and anaerobic bacteria that can decompose organic matter and transform nitrogen and phosphorus elements. When decomposing the nitrogen-containing compounds in industrial wastewater, the heterotrophic denitrifying bacteria in the biofilm can use the carbon source in the wastewater to reduce nitrate nitrogen to nitrogen gas and discharge it from the system, achieving nitrogen removal from the wastewater.

Similarly, for various heavy metal ions in the wastewater, some microorganisms can secrete extracellular polymeric substances (EPS) to adsorb and fix them. This reduces the mobility of heavy metal ions and makes them more stable, ultimately improving the clarity of the wastewater.

 

Do you think that MBBR media are consumables? In fact, that's not true. Their expected lifespan varies depending on many factors, but generally, they can last for 10 to 20 years. Moreover, MBBR media manufacturers are using more chemically stable, tough, and biocompatible polymer materials to make these media. Take HDPE carriers as an example. Their chemical structure is very stable, so they are not easily corroded by acidic and alkaline substances in the wastewater or broken due to aeration impacts.

In addition, the manufacturing cost of the carriers is continuously decreasing with the maturity of the production process and large-scale production. Nowadays, the cost of MBBR carriers only accounts for a small proportion of the entire wastewater treatment system. They are hardly an economic burden for any wastewater treatment manufacturer.

 

Some people also think that the MBBR process requires continuous aeration and pushing the carriers to flow during operation, which will consume a large amount of energy. However, compared with the traditional activated sludge method, under the condition of achieving the same treatment effect, the MBBR requires less aeration. Even if the outer-layer aerobic microorganisms on the biofilm continuously consume oxygen, the inner-layer facultative anaerobic and anaerobic microorganisms can still continuously decompose the waste in the wastewater in a low-oxygen environment.

In addition, relying on the driving force of the water flow, the MBBR carriers can be evenly distributed and move naturally in the tank. You don't need to purchase special stirring equipment to push the carriers. Instead, you can reduce the energy consumption through energy - saving aerators and intelligent variable frequency control devices.

The above are some of the misconceptions about MBBR media in wastewater treatment. We need to have a more accurate understanding of and make better use of this wastewater treatment technology. If you have any other questions about the above content or are considering adopting an MBBR system for your actual project, please feel free to contact us for consultation.