In the beginning of 1900s, many of the lakes and rivers in Finland were severely polluted by industries and municipalities. After 1970s, technologies, practices and legislation rapidly developed to handle industrial and municipal wastewater in an efficient and effective manner. Today, the sector is developing towards circular economy and resource recovery in terms of energy, nutrients and clean water.
Wastewater treatment plants in Finland
- 540 WWTPs (PE > 50), mostly municipally owned
- Treatment requirements set in environmental permits
- Mixed tariffs (flat fee + volume fee + connecting fee)
- Full cost recovery (O&M + investments)
- Average BOD removal 97,8 % (developing economies: 60 %)
- Average phosphorus removal 96,2 % (developing economies: 50 %)
Most of the WWTPs in Finland utilize a primary treatment for solids removal, activated sludge process for phosphorus and nitrogen removal and tertiary treatment with activated carbon or UV disinfection.
Membrane bioreactor (MBR) process enables even more efficient treatment with less space requirements for different process steps. Steady high quality effluent water can be re-used for many purposes and even meets the criteria for drinking water quality. Produced sludge can be converted into sustainable fertilizers and renewable energy, allowing efficient recovery of valuable resources.
Metsä-Sairila WWTP – circular economy is the future
A full MBR plant is being built to Mikkeli to serve as a platform for developing future circular economy solutions. Treatment efficiency of the plant will exceed the requirements set in the environmental permit. High-quality effluent enables water re-use for different purposes, e.g. cooling and fire extinction. Plant will be operational in 2020.
Finnish water expertise at your service
FWF members provide high-level expertise for comprehensive wastewater treatment solutions. Contact us to learn more about Finnish experiences.