Fuel and fertiliser from waste water sludge
Sludge from waste water treatment plants usually ends up in incineration plants, with nutrients and energy being lost. A new Dutch technology makes the process less wasteful and potentially saves millions of dollars.
The patented technology, registered under the trademark ‘TORWASH’, separates water from the sludge. As a result the total volume of sludge produced in the water treatment process is reduced by as much as 85%.
Furthermore, TORWASH makes it possible to produce biogas from the liquid effluent which can be used as fuel to power the water treatment plant. At the same time, nutrients such as phosphorus can be recovered and reused as fertiliser.
For the development of TORWASH, TNO worked together with Paques, an expert in sustainable water and gas processing techniques, the national water research institute STOWA and the Zuiderzeeland Regional Water Authority. Involving businesses, knowledge and research institutes, and government, TORWASH is the result of ‘triple helix’ cooperation, a model used widely in the Netherlands.
TORWASH, which was tested at a small-scale pilot plant in 2018, has the potential to make waste water treatment more cost efficient and more sustainable.