Norrmejerier dairies - Use of biological wastewater treatment to generate energy, preserve resources and lower operating costs
In June 2005 at the Norrmejerier dairies in Umeå (Sweden), the Swedish environment minister, Lena Sommestad, inaugurated the company’ s first Biomar® plant for the biological treatment of wastewater. The project was supported by the EU.
The organic substances left behind by rinsing during milk processing and found in whey and whey permeates are acidified, hydrolysed and conditioned. This creates the optimum conditions for subsequent anaerobic wastewater treatment. This takes place inside two methane reactors. Here, biogas is produced, which can be reused at the dairy.
The Biomar® wastewater treatment plant cleans and disposes of wastewater from production, as well as generating biogas. Not only does this represent best ecological practice, but there are also economic benefits. Ever since the Norrmejerier dairies started feeding in whey permeates from other factories they own in Northern Sweden, biogas is produced every day. The gas is used to generate steam, thereby reducing fuel costs at the dairy.
"In this way, not only are we saving on primary energy, but we are also reducing our costs by 2,500 euro a day", says Olof Wallin, the man behind the company, with pride. "The others certainly have some catching up to do…"
The plant solution for anaerobic wastewater treatment in combination with an energy recovery approach, which was designed with economical and environmental considerations in mind, has been in operation since 2005. The disposal costs could be significantly reduced.
At a glance:
Plant technology for energy efficiency and protection of resources
- Produced 2 million m³ of biogas from wastewater during 2009.
- Saved 1.2 million l heating oil during 2009
- Recovers thermal energy