Plants absorb metal ions through their roots. Phytoextraction is not yet used to extract metals for commercial purposes but it does help remove toxic metals from contaminated soil (for example around old mines).
In the future, when supplies of higher grade ores have run out, metals could be extracted by burning the plants to produce ash. The ash would contain a higher concentration of the metal than the soil.
Explain why phytoextraction is not currently used by mining companies for extracting metals.
Phytoextraction only produces a small quantity of metal and is very slow. Mining companies can make more money from other methods of extraction.
Copper(II) sulfate solution is produced and is carefully collected.
This solution is called a leachate and the process is called bioleaching.
A disadvantage of bioleaching is that it introduces toxic substances, including sulfuric acid, into the environment