The MBBR Sewage Plant - The Who, What When Where, Why and How

Sewage Plant

If you’re looking into biological water treatment methods and which one could be the best for your application, perhaps you’ve come across moving bed biofilm reactor (MBBR) technology. You probably have a few general questions as to how it works and how it can help you meet your particular needs, but are having a hard time finding answers while searching the internet.

So, to help you in your quest for answers here is a quick outline of the WHO, WHAT, WHEN, WHERE, WHY, and HOW of the moving bed biofilm reactor biological sewage plant process in wastewater treatment.

WHO can use it?

Answer: MBBR is useful in particular applications within multiple sectors such as:

  • Food & Beverage

  • Dairy Processing

  • Decentralized Wastewater Treatment for Hotels/Facilities, Camps, Community Developments

  • Pulp & Paper

  • Pharmaceutical

  • Small Municipalities/Communities (Existing Retrofit and Decentralized)

WHAT does it treat?

Answer: As a biological sewage treatment plant process, MBBR is particularly good at reducing organic materials in the form of:

  • BOD

  • COD

  • TSS

  • Nitrification

  • Odors

WHEN should we consider implementing it?

Answer: ASAP! It’s never too early to improve an existing sewage plant or to add in a new one. If you’re concerned about needing to rehaul a treatment system that is already in place, MBBR units can be modular and are easy to add to an existing system for potential improved process efficiency based on current sewage plant configuration.

WHERE can it be used?

Answer: Within a treatment process? Usually during secondary treatment, which is typically when any biological treatment is done, following removal of large solids and inorganic material and preceding any necessary filtration and disinfection. Physically? Thanks to their design, MBBR sewage plants typically are designed with compact footprints. Therefore, they can fit in smaller areas and may not even require extra land development.

HOW does it work?

Answer: Like most biological treatment processes, MBBR involves natural cellular digestion and decomposition to break down the organic wastes in wastewater. The way it does this process, is through a biofilm, which is simply a layer of bacteria and protozoa that has adhered to a surface. In the case of MBBR, the surface that the biofilm sticks to is on the inside of small plastic carriers (media). The carriers can come in many shapes, but most commonly resemble wagon-wheel pasta; stout cylinders with a number of inscribed crosses and concentric circles. The pockets created by the inscribed shapes increase the available inner surface area for the biofilm to adhere to. The outer surface is typically ridged or finned to increase the outer surface area for bubbles or moving fluid to keep the carriers moving within the influent. Also to aid in the flotation of the carriers, the plastic they are made of has a similar density to water, commonly high-density polyethylene (HDPE).

Essentially, the carriers are specialized media that are designed to carry as much biofilm as possible and move about within the reactor. The motion of the biofilm-coated carriers is to increase contact with the substrates within the influent. The micro-organisms within the biofilm break down the organic substrates and the resultant solution is pumped to a clarification stage to separate the clean water from the biomass.

The carriers are kept within their own tank by a mesh sieve mounted to the outlet.

WHY should we use it?

Answer: There are plenty of advantages to using an MBBR system in your municipal or commercial/industrial sewage plant operations.

  • Simple operation – MBBR systems are practically a one and done process with no additives and a self-regulating biofilm so operators don’t need to heavily monitor and adjust system influents. The most significant monitoring is of the biofilm itself, which does require skilled workers.

  • Small footprint – with their small size, lack of need for chemical additives, and long lasting biofilm and carriers, MBBR systems have small footprints which makes them very environmentally friendly.

  • No recirculation – because MBBR is a fixed film process, the biofilm will stay within the same tank as long as the carriers don’t get out and that can be resolved with a well-designed tank and mesh sieve screen on the outlet piping.

  • Low power consumption – The only power required for MBBR units is for any controls systems and the aeration mechanism. Bubble diffuser can require higher amounts of power and they are run constantly, but the energy usage can be decreased by using integrated course bubble/nano bubble diffuser systems.

  • Stable under large load variations and high flows – Unlike some other biological treatment processes, MBBR is able to re-acclimate itself when the volume or composition of the water in the sewage plant changes.

  • Easy retrofitting – Most MBBR units are modular or are designed to have a compact footprint so they may be easily added into any existing treatment process system as required.

** WHERE can you find more information on MBBR?


If you have any questions about moving bed biofilm sewage plants, how they work, how they could assist your company or municipality, or where to design/procure one, give Genesis Water Technologies, Inc. a call at 1-877-267-3699 within the USA or reach out to us via email at to speak with a representative who can knowledgeably answer questions that you may have.