A non-native invasive plant has been found to successfully remove heavy metals from a polluted Welsh river.
Natural Resources Wales (NRW) used water hyacinths, which feature on the European Commission's list of species of EU wide concern, to treat the Nant-Y-Fendrod in Swansea which is failing to meet water quality standards under the Water Framework Directive.
Nant-Y-Fendrod is a tributary of the River Tawe, which in turn drains the Lower Swansea Valley into Swansea Bay in South Wales. There is an estimated 7 million tonnes of copper and zinc smelting waste abandoned on the valley floor.
NRW placed the plant in the river as well as using a bankside treatment system and recorded the removal of 21 different elements from the polluted river water, with 100% of cadmium, cobalt and manganese contaminants extracted from the water and 80% of zinc removed over a three-week period. The results were published in the journal Nature last week.