Researchers from Stockholm University have discovered a moss that has the ability to eliminate arsenic from contaminated water. This process takes place in just an hour, and also the arsenic level is so low that the water is safe to drink. The results of the study have been reported in the journal, Environmental Pollution.
Aquatic moss in Stockholm University greenhouse. (Image credit: Photo: Arifin Sandhi)
Warnstofia fluitans, an aquatic moss which grows in the northern part of Sweden, can rapidly adsorb and absorb arsenic from water. This finding paves the way for an eco-friendly method to remove arsenic from drinking water. This can be possibly achieved by cultivating the moss in streams and other water bodies that contain elevated levels of arsenic.
Water in Mining Areas Often Contaminated
Arsenic is known to contaminate water in mining areas located in the northern part of Sweden.
We hope that the plant-based wetland system that we are developing will solve the arsenic problem in Sweden’s northern mining areas,” says Maria Greger, head of the research team and Associate Professor at the Department of Ecology, Environment and Plant Sciences at Stockholm University.
High Capacity for Quick Uptake of Arsenic
Our experiments show that the moss has a very high capacity to remove arsenic. It takes no more than an hour to remove 80 per cent of the arsenic from a container of water. By then, the water has reached such a low level of arsenic that it is no longer harmful to people
Arifin Sandhi, Research Assistant
The use of arsenic compounds in wood products was banned in 2004, but due to mining activities arsenic continues to reach the ground and water systems. This occurs because arsenic is naturally present in the bedrock and ground in some parts of Sweden. Consequently, the drinking water as well as the water used for crop irrigation has high levels of arsenic. The arsenic, absorbed from the soil by the plants, ultimately makes its way into the food consumed by people. In Sweden, this holds true for leafy greens, root vegetables, wheat, among others. In other regions, high levels of arsenic are present in rice, for instance.
How much arsenic we consume ultimately depends on how much of these foods we eat, as well as how and where they were grown. Our aim is that the plant-based wetland system we are developing will filter out the arsenic before the water becomes drinking water and irrigation water. That way, the arsenic will not make it into our food.
Maria Greger, Head of the Research Team