Leicester’s De Montfort University reports: The world’s fastest-growing aquatic weed has effectively removed toxins from a polluted river in the UK – a finding which has the potential to revolutionise environmental clean-ups. The plant’s roots were able to absorb metals and pollutants such as copper, zinc, arsenic, lead and cadmium. In some cases, the plant completely removed all traces of the metal within three weeks.
The trial was carried out at Nant-Y-Fendrod, a tributary of the River Tawe near Swansea, which was a focal point of global copper production in the 19th and 20th centuries. Prof Haris said some estimates were that some seven million tonnes of copper and zinc smelting waste was abandoned on the valley floor there.
Despite efforts to remediate the land, it still contains heavy metals, and fails to meet EU water quality standards. Prof Haris’ PhD student Jonathan Jones, a senior environment officer at Natural Resource Wales (NRW), carried out the proof of concept study by growing the water hyacinth in river water to assess metal removal efficiency; in the laboratory, in the stream itself and along the riverbank.