A study published in the JNKVV research journal in 2015 concluded that heavy metal pollution of soil is “emerging at a speedy rate” in India due to industrialisation.
Turning toward more sustainable and eco-friendly technologies, scientists have developed methods of “Phytoremediation”, a remediation method that uses living organisms like plants, microalgae, and seaweeds.
What is ‘phytoremediation’?
- Phytoremediation refers to the use of plants and associated soil microbes to reduce the concentrations or toxic effects of contaminants in the environment.
- Phytoremediation is widely accepted as a cost-effective environmental restoration technology. Phytoremediation is an alternative to engineering procedures that are usually more destructive to the soil.
- Phytoremediation of contaminated sites should ideally not exceed one decade to reach acceptable levels of contaminants in the environment.
- Phytoremediation is, however, limited to the root-zone of plants.
- Also, this technology has limited application where the concentrations of contaminants are toxic to plants.
What are hyperaccumulator plants?
- Phytoremediation refers to the usage of “hyperaccumulator” plants to absorb the toxic materials present in the soil and accumulate in their living tissue.
- Even though most plants do sometimes accumulate toxic substances, hyperaccumulators have the unusual ability to absorb hundreds or thousands of times greater amounts of these substances than is normal for most plants.
- Most discovered hyperaccumulator plants typically accumulate nickel and occur on soils that are rich in nickel, cobalt and in some cases, manganese.
- These hyperaccumulator species have been discovered in many parts of the world including the Mediterranean region (mainly plants of the genus Alyssum), tropical outcrops in Brazi, Cuba, New Caledonia (French territory) and Southeast Asia (mainly plants of the genus Phyllanthus).
Advantages of phytoremediation –
- One of the primary advantages of phytoremediation is the fact that it is quite cost-effective in comparison with other remediation methods.
- The only major costs attached are related to crop management (planting, weed control, watering, fertilisation, pruning, fencing, harvesting etc.). This method is also relatively simple and doesn’t require any new kinds of specialised technology. Also, no external energy source is required since the plants grow with the help of sunlight.
- Another important advantage of this method is that it enriches the soil with organic substances and microorganisms which can protect its chemical and biological qualities. Also, while the plants are growing and accumulating toxic heavy metals, they protect the soil from erosion due to wind and water.