New project extracts phosphorus from waste water

Lack of phosphorus might turn out to be one of the largest challenges of the future. As a nutrient, it is an essential factor in the growth of plants, and because of this, it plays an important part in food production to a globally growing population. At the same time, naturally occurring phosphorus, which can be extracted for fertilizer, is a limited resource which threatens to be exhausted. Because of this, recycling of phosphorus and new ways of extracting it, have become areas which receive attention on a global scale.

In collaboration with among other Aarhus Vand, a municipal water supply company in Aarhus, Denmark, Grundfos is partnering in a project, where new technologies for extracting phosphorus from waste water are being tested at Åby purification plant. The plant was opened on 11 November, with attendance by among others the Danish Minister for Environment, Ida Auken.

- The Danish government wishes to make a green switch of Denmark. Here we have an example of what green transformation is all about. We develop solutions to environmental issues, which at the same time can generate new business from which we can live in the future. The discharge of phosphorus to the water environment is not only a challenge in Denmark. It is a global problem, which offers perspectives in finding a way of solving, she says.

A problem and a possibility

At Aarhus Vand, they have worked with phosphorus removal from waste water since 2011. The rare element has the unfortunate side effect that it deposits in the pipelines, making them clog.And when the water company in another context learned that in Oregon, USA, they were far ahead in the work with recycling phosphorus, the project started to take off.

- There is a vast potential in extracting phosphorus from waste water. And from our perspective, we get to solve a problem and make use of an opportunity in one swoop. Partly by avoiding clogging our pipelines, partly by extracting and making use of a scarce resource in a sustainable way, says Claus Homann, Department Head at Aarhus Vand, and explains that it is probable that the plant in Åby can be developed to extract 60 per cent of the phosphorus from the waste water.

Builds on existing technology

One of the partners in the project is Grundfos, who supplies highly specialized components to the extraction of the phosphorus in the shape of dosing pumps, booster systems and controls to the purification plant.

- We think it is interesting to see, how our solutions can play a part in the project. We have already got the technologies, so what we are looking at is to utilize them in a new way. At first we are testing how it all works, before we decide whether or not this is something we want to move on with, says Per Krøyer Kristensen, Business Development Manager at Grundfos.