Sludge is a global problem in water treatment facilities that occurs in different process conditions. At the same time, sludge is a potentially important energy source (within the EU approx. 840 GWh/year) that today cannot be fully exploited since there is no solution for collecting it effectively.
Currently, sludge is managed through manual flushing or being pumped away by vacuum trucks. The use of vacuum trucks requires a considerable amount of water which, depending on how the water treatment plant is built, can result in the loss of the energy potential of the sludge. If the sludge can be collected without water, the water treatment plant can instead convert it to bioenergy and take advantage of phosphorus and, at the same time, minimize operation stoppages, operation costs, energy and chemical use.
SurfCleaner has a patented technology that collects and separates the sludge in an energy-efficient way – this will enable a significant increase in bioenergy from municipal waste streams. This technology will now be validated as a complete system that can be integrated into existing waste treatment plants in Sweden and internationally.
In this project, SurfCleaner together with several water treatment plants and industry partners in Sweden (Tekniska verken in Linköping and Nodra in Norrköping) will evaluate how SurfCleaner’s technology can be integrated into the water treatment plants’ existing processes and systems.
The Swedish Energy Agency has granted financial support for the implementation of the project “Full-scale test of SurfCleaner for collecting and separating sludge in water treatment plants” from November 2020 to June 2022.
“Tekniska verken wants to be a driving force in the development of new innovations, not least of which is establishing future-proof, resource-efficient solutions in the region. Through close collaborations with companies such as SurfCleaner, we want to create long-term profitability and efficient, secure operations.”
"It is fun and exciting to be involved in the development of an innovative and sustainable solution that can replace today's manual and resource-intensive handling of sludge."
“We are excited about the opportunity to continue developing our unique machines for treatment plants so we can contribute to finding solutions to global challenges. We want to show that the treatment plants can solve their problems with sludge, save costs and use sludge to increase biogas production – a very important future energy source, not only in Sweden but worldwide.”

With and without SurfCleaner. Images from Nykvarnsverket in Linköping, Sweden.
Initial tests
During 2019-2020, SurfCleaner, together with Tekniska verken in Linköping and with funding from the Swedish Energy Agency, has successfully carried out the initial tests of this patented technology that makes it possible to collect and separate the floating sludge in an energy-efficient way.
In that project, a SurfCleaner has been placed in 1 of 4 lines in a biological stage at Nykvarnsverket at Tekniska verken in Linköping. Cameras have been installed during the test period and comparative images show that the SurfCleaner removes the sludge and that the technology works.
“During the year we have tested SurfCleaner in one of our pools for biological treatment, we have seen that it effectively removes sludge. We are now looking forward to finding solutions to take care of the collected sludge in an energy-efficient way.”
The Swedish Energy Agency has granted the project financial support corresponding to approximately 41% of the total project cost of €850,000.