“Rent blås” – monitoring and maintenance of aeration diffusers

Rising electricity prices and the accelerating climate crisis make energy efficiency a high priority for Swedish wastewater treatment plants.

A VA SYD PROJECT The largest part of electricity use is normally due to aeration of the biological treatment steps, which often account for 30–50 percent of the electricity usage. A potentially large part of this electricity usage is avoidable and associated with fouling and aging of the diffuser membranes. In international studies, up to 40 percent decrease in efficiency has been observed after a few years. However, the experience from Swedish treatment plants is very limited.
It is possible to restore some of the lost aeration performance (back pressure and oxygen transfer efficiency) through maintenance, but there is a lack of methods to monitor the performance of the diffusers during operation and therefore, there are no tools to perform condition-based maintenance.

During the project, the condition of diffusers at Swedish treatment plants of different sizes and with different processes and types of diffusers will be analyzed through clean water testing. At some of the treatment plants, performance monitoring methods will be implemented and evaluated.