Phytoextraction is slow, but it:
Suggest reasons why phytoextraction decreases the damage done to the environment.
Mining for metal ores involves quarries, which are large holes in the ground. These create noise, dust and traffic. They also destroy natural habitats. Phytoextraction reduces the need for mining so reduces this damage.
Give one disadvantage of phytoextraction.
It is a slow process.
Certain bacteria can break down ores to produce an acidic solution containing copper(II) ions. The solution is called a leachate and the process is called bioleaching. Bioleaching does not need high temperatures, but it produces toxic substances, including sulfuric acid, which damage the environment.
Iron is more reactive than copper. It can displace copper from the leachate. For example:
iron + copper(II) sulfate → iron(II) sulfate + copper
Fe(s) + CuSO4(aq) → FeSO4(aq) + Cu(s)
Since iron is cheaper than copper, the use of scrap iron is a cost-effective way to produce copper from the leachate.