Claude Grison

Decontaminating polluted soils with metal-eating plants

Technical field
Environmental technology
Centre National de la Recherche Scientifique (CNRS) and the University of Montpellier
Researcher Claude Grison has developed a method of using plants to extract metal elements from polluted soil, and then uses these elements as "ecocatalysts" to make new molecules for the chemical, pharmaceutical and cosmetics industries.

Winner of the European Inventor Award 2022

While most plants cannot grow in contaminated environments, certain species have adapted to thrive there. Moreover, these plants can help to clean contaminated soil by absorbing metal elements such as zinc and nickel into their structures - a technique known as phytoremediation. French researcher Claude Grison has found a way to take this process further by extracting the metals from the plants and using them as a source of catalysts for chemical reactions.

Once the plants have taken up metal elements from contaminated soil, they are harvested and heated to remove all organic matter, leaving only metal salts. These are treated to become catalysts. To date, Grison and her team have successfully used ecocatalysts to synthesise 5 000 different molecules. The technology can be applied for various strategic purposes, such as recovering expensive rare metals, or primary metals with dwindling reserves such as zinc, nickel, copper and manganese. Following decontamination, native species can be replanted in the rehabilitated soil to expand biodiversity.

Growing the green chemistry market

The ecocatalysts retrieved by Grison and her team's invention are part of a growing green chemistry industry, which aims to reduce or eliminate toxic chemicals from everyday chemical processes. To commercialise her research, Grison established four start-ups and has collaborated with chemical, pharmaceutical and cosmetics companies including Belgarena, Colas, Klorane and Chimex.

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