Field testing in Rävlanda, Sweden – “Visible results in just two weeks”

Since February, Hydria Water has been conducting field testing of channel filters at the Rävlanda and another, as yet secret, patent-pending solution at the Rävlanda wastewater treatment plant.

– Previously there was an older mechanical step-type screen; now the water from the pumping station is directed to our channel filter, which is the first part of the wastewater treatment plant and handles around 3500 pe, Rikard Karlsson at Hydria Water explains.

In 2019 the wastewater treatment plant filtered a total of 550 kg material, but with the new channel filter the screening has become almost too efficient, and in just two months 450 kg material was filtered.

Patrik Eliasson is an operations technician at Rävlanda wastewater treatment plant. He laughs when he remembers the panic-purchasing of waste containers shortly after the new machine had been installed.

– Before, two waste containers per week was enough, but with this machine we need six waste containers a week!

The field test is the largest that has been conducted at the plant since it was renovated 20 years ago, according to Patrik.

– I’m delighted; the process has been entirely smooth. The old screen is about to give up, but now I don’t think I would want to go back to that type of solution again. The technology and results are better with this solution – in addition, there is less sedimentation of sand and gravel in the machine than before, he says.

– The pre-sedimentation tank is cleaner than before, as is the picket fence thickener. It took only two weeks for a change to become visible in the sedimentation tanks and sludge; now, the amount of rags and cotton buds is vastly reduced.

Between February and the middle of May, the machine operated for 130 hours. The project will be concluded by the end of the summer.

– We are very grateful to have been given this opportunity. We’re very happy with the collaboration and feel that it has worked very well; the plant is situated in our local area, and provides us with opportunities for exciting product developments, Rikard says.