Veolia to deliver world’s biggest MBBR system to Sweden WWTP

April 26, 2023
The Käppala wastewater treatment plant will use the largest MBBR system in the world to tackle a growing population and new emission permits.

Veolia Water Technologies announced that its subsidiary AnoxKaldnes will supply its moving bed biofilm reactor (MBBR) system to support the upgrade of Käppalaverket (Käppala wastewater treatment plant) in Lidingö, Sweden.

Owned by Käppalaförbundet (Käppala Association), the plant treats wastewater from more than half a million people in 11 member municipalities north and east of Stockholm.

AnoxKaldnes has signed the contract with NCC, one of the leading construction companies in the Nordic Region. NCC will utilize their complex project expertise for the execution of the construction and implementation of the new treatment works.

The Käppala wastewater treatment plant (WWTP) is facing an increased load from affiliated municipalities combined with stricter emission requirements. The Käppala Association therefore plans to expand the capacity of the plant to cope with an incoming load corresponding to 900,000 population equivalent (p.e.) in 2050 and meet the new emission permit that will enter into force in 2026.

When completed, the Käppala WWTP will be the largest MBBR system in the world. Each line of the existing system is approximately 18,000 m3 in volume and will be divided into nine individual zones in order to meet the challenging new requirements. The five MBBR lines will be treating 80% of the incoming pollutant load and the flow.

The Käppala WWTP is built underground and the activated sludge lines are blasted from the bedrock meaning that the walls of each line are exposed raw bedrock. Logistics, MBBR carrier durability and expertise were three of the key reasons why AnoxKaldnes was selected to be the delivery partner for this project.

“To be part of a great team working on this huge scale project to improve the environment in our own country makes me extremely proud — this is a historical win for AnoxKaldnes,” said Jacob Bruus, CEO of AnoxKaldnes.