4.4 - Phytoremediation

Definition of Phytoremediation

Phytoremediation is an alternative method of water treatment that uses plants to eliminate, degrade and extract pollutants such as heavy metals in the soil and water. This word comes from 'phyto' (ancient Greek) and 'remediate' (Latin) which mean plant and repair respectively.

The example of plant that can help in phytoremediation is Eichhornia crassipes (water hyacinth).

Figure 9 - E. crassipes has long roots that can gather heavy metals such as copper and lead in water.

The Uses of Phytoremediation in Life

Sunflower

• Used in soil remediation polluted by the explosion of nuclear plant in Chernobyl, Russia.
• Acts as a hyperaccumulator that eliminates metals (zinc, lead, copper and chromium) and radioactive substances (caesium and strontium).

Pistia stratiotes (Water lettuce)

• Aquatic plants used to treat waste water in a waste plant through phytoremediation.
• High growth rate and ability to gather heavy metals as well as absorbing nutrients in the waste plant.

Ground water spinach

• The roots can absorb mercury from the soil.

River water spinach

• The roots can absorb heavy metal like cadmium from the water.