MBBR: A Small Solution with Big Results

In a crowded marketplace, moving bed biofilm reactor (MBBR) systems stand out for their practicality, usability and cost-effectiveness. In this blog, we detail why the small footprint wastewater treatment solution is so effective for existing facilities, as well as new sites.

Nowadays, there are a number of treatment systems designed to help firms deal with wastewater and sewage. Despite the competition, few technologies can offer the same combination of benefits as a MBBR system for both municipal and industrial applications. First devised by AnoxKaldnes over 40 years ago, the highly effective biological treatment provides a simple to operate, compact solution. As a result, the system is the perfect fit for both new installations and the upgrade or expansion of existing sites, especially where space is limited. What’s more, as MBBR systems have the ability to cope with varying loads, they are suitable for use within plants that experience peaks in treatment loads, or tight discharge limits.

At the core of the MBBR system is its biofilm carrier elements. These carriers are made from polyethylene and are designed to provide a large protected surface for the bacteria culture that facilitates the removal of biochemical oxygen demand (BOD), ammonia and nitrogen. To achieve this, the carrier elements, which have a density slightly below that of water, are kept suspended in the water by air from the diffusers in the aerobic reactors and by means of a mixer in the anoxic reactors. Thanks to this approach, MBBR systems can perform effectively across a spectrum of applications, including use as a sole bio-treatment, a pre-treatment and a post-treatment. 

We also offer a MBBR package system, which uses the AnoxKaldnes™ media for developing the micro-organisms biofilm for the biological treatment of wastewater, and covers most flows and pollution loads. The solution provides all the advantages of a conventional MBBR system, in a standard prefabricated solution allowing customers to deal with specific site requirements and quality objectives. At Veolia Water Technologies, we also offer a MBBR liquor treatment process called ANITA™ Mox, which has been developed for the treatment of streams highly loaded in ammonia based on the Anammox bacteria. 

We have installed our MBBR systems for both municipal and industrial customers and are able to utilise our expertise from both markets for every application we work on. From our experience, MBBR systems can deliver significant benefits on existing treatment facilities, which need extra capacity. This is because MBBR systems can be used as a high-loading system in front of an existing biological treatment. For example, if an existing facility needs to respond to tighter discharge limits, then installing a MBBR system can be a great solution. On such projects, a MBBR system can help facilities to take the load off an existing site, allowing the new, higher level of treatment to be achieved or creating more treatment capacity.

This benefit was underlined during an installation at Cudworth Sewage Treatment Works (CSTW). In line with its asset management plan, the facility needed to increase capacity to serve a 2025 population equivalent of 10,693. Similarly, the site needed to treat its wastewater to a more stringent discharge quality. 

The long-term performance and cost-effectiveness of our MBBR system made it the most suitable choice. To this end, we installed an AnoxKaldnes™ MBBR process for residual BOD removal and nitrification. Immediately after the system’s installation performance on site improved. Thanks to the MBBR system, the secondary effluent from the existing humus tanks can now be pumped into a splitter box to the 2 MBBRs streams, followed by the discfilter filtration units and discharged to the River Dearne via the existing outfall. Unlike before, the wastewater is virtually ammonia free, which means it meets the Environment Agency’s new regulations on water quality , which came into effect at the start of April.

As well as their efficiency, MBBR systems provide a small footprint solution, which makes them easier to fit on new or existing facilities. Additionally, MBBR systems are the ideal solution for facilities that need to increase capacity but can’t expand the site’s footprint. This was demonstrated during work at a fish farming facility called Marine Harvest Dalsfjord in Norway. The site needed to build two separate recirculating aquaculture systems (RAS) plants, but had limited space. RAS plants, which are increasingly common across fish farming, use indoor tanks to rear high densities of fish. The system creates a more controlled environment for fish to grow and can help to reduce water consumption when compared to traditional, open ponds. 

Fortunately, our team was able to help, designing both RAS plants in an extremely compact manner. To this end, the first RAS plant was able to treat 2,850 m3 water in a footprint of just 200 m2. Similarly, the second facility was built with a capacity to provide 2,000 kg per day of feeding to the fish, with a total hydraulic capacity of 2,400 m3 every hour despite a footprint of less than 250 m2. 

Some firms feel uneasy specifying water treatment systems that they feel unfamiliar with. Fortunately, MBBR systems are inherently easy to operate. From our experience, on-site staff tend to learn how to use the system quickly. However, we are also on hand to provide technical support and guidance should an issue occur. Similarly, when compared to alternative approaches, MBBR represents a cost-effective solution, especially when used as a pre-treatment upstream of an existing secondary treatment process such as activated sludge plant or trickling filters. The technology is quick and easy to install, offering plug and play function, which reduces on-site construction time. Furthermore, through their lifecycle, MBBR systems require minimal maintenance. 

At VWT UK, we’re proud to be world leaders in MBBR systems and have been involved with the technology since its creation almost 40 years ago. Since then we have continually invested in research and development to improve our MBBR systems and bring new advances to the market. Over the years, we’ve supplied the solution to over 1,000 projects. Through this experience, we’ve been able to grow what’s possible with the system and we can customise the solution to meet specific site goals. This includes creating systems with our patented alternating flow configurations, or systems that can be implemented into the post-treatment of existing plants. As a company, we’re also able to provide all these advantages in a standard prefabricated package. As such, the reliable and robust MBBR solution is now accessible to all.


For more information about MBBR Technologies please visit:

MBBR Learn More


William Jeal

About the Author

William Jeal

William has a background of working with a wide range of industrial, public sector and municipal customers. William's career in the water sector started with a start up services business focused on working with commercial, industrial and public sector organisations to manage their water and wastewater usage, costs and environmental compliance. Having grown and developed this business for 5 years William then joined Veolia Water Technologies in 2015 to focus on growing its wastewater technologies activities in the Municipal market. In 2019 William took responsibility for leading Veolia's Municipal Services Business as well as its Digital Services Business across all sectors in the UK. With a strong focus on commercial and service innovation William has been responsible for a number of development projects including involvement in the development of Veolia’s global AQUAVISTA platform of real time control and optimization services.