In Sweden and in many other countries in Europe, efforts have been made for many years to prevent eutrophication in lakes and coastal waters caused by phosphorus. The company Vattenresurs has a patented method for effectively improving the water, which is at the same time gentle on animal and plant life. In the work of purifying water, specially built boats are used, which Jernbro has built.
To stop the leakage of phosphorus, Jernbro has, on behalf of Vattenresurs, built two boats. These have a long beam at the front from which hoses hang down in the bottom sediments. There’s also a tank in which aluminum salt is stored. From the tank, the aluminum salt is pumped out through the beam and down into the hoses to be injected into the sediments and tie up the phosphorus.
– The new boat will have its premiere tour this autumn and will then work with cleaning the lake Lejondal for about 1.5 years. The former, which has been running for almost a year, has so far purified about 4 lakes, says Göran Andersson, marketing manager at Vattenresurs.
The two boats are 30 meters long. The latest one has a bigger tank and a longer beam. The longer beam makes the work much more efficient since wider lanes simply can be treated. The larger tank contributes to the fact that you don’t have to go ashore and refill the tank as often.
– The latest boat that we have built, weighs about 10 tons and is welded together from stainless steel plates. The boat consist of several floating bridges that have been welded together, of which one part is a large tank, says Peter Johansson, head of Jernbro’s welding department in Skövde.
– In the manufacture, we have used the processes that we always work with and which we thus have good competence and experience of, such as edge pressing, cutting of plates and welding. This work has been really fun and valuable, because it has an environmental value, says Peter.
– At Jernbro, we saw the skills required to build the specially adapted boats. It has really been a well-functioning and smooth collaboration. It has been characterized by enthusiasm for the somewhat odd project and the feeling of contributing to a better water for animals, nature and people, Göran concludes.
– What we do practically is that we add aluminum salt to the sediments in the water which ties up the phosphorus. This settles on the lake bottom and eventually becomes a mineral. Phosphorus disappears quickly with this method and the water quality improves almost immediately. Therefore, this is a very grateful method, says Göran Andersson.
