Veolia Water Technologies’ subsidiary AnoxKaldnes, an expert in moving bed biofilm reactor (MBBR) based solutions, will supply its space saving and capacity increasing solution to support the upgrade of Käppalaverket, aKäppala wastewater treatment plant (WWTP) 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 construction companies in the Nordic region. NCC will utilise their project expertise for the execution of the construction and implementation of the new treatment works.
The Käppala WWTP is facing an increased load from affiliated municipalities combined with stricter emission requirements. The Käppala Association plans to expand the capacity of the plant to cope with an incoming load corresponding to 900,000 population equivalents in 2050 and meet the new emission permit in 2026.
When completed, the Käppala WWTP is said to be the largest MBBR system in the world. Each line of the existing system is approximately 18,000m3 in volume and will be divided into nine individual zones in order to meet the challenging new requirements. Due to AnoxKaldnes MBBR systems, 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 where the walls of each line are exposed raw bedrock. AnoxKaldnes provided its AnoxK5X carrier due to its logistics, MBBR carrier durability and expertise.