In News
- Scientists have planned to use hyperaccumulator plants to remove toxic metals from soil using the phytoremediation process.
- Toxic heavy metals are absorbed by plants from where they make their way into our food chain thus affecting human life along with ecology.
What is Phytoremediation?
- About:
- Phytoremediation is a bioremediation process that uses living organisms like plants, microalgae and seaweeds to remove toxic heavy metals from the soil.
- It is a sustainable and eco-friendly technology compared to other technologies used in removing toxicity from the soil.
- The process can be used for faster removal of toxicity using hyperaccumulator plants that absorb these substances from the soil in greater amounts.
- Hyperaccumulator plants:
- Hyperaccumulator plants are those that have an unusual ability to absorb hundreds or thousands of times greater amounts of toxic substances from the soil compared to other plants.
- They can remove metals like silver, cadmium, cobalt, chromium, copper, mercury, manganese, molybdenum, nickel, lead and zinc; metalloids such as arsenic and selenium; some radionuclides; and non-metallic components such as boron.
- However, they cannot remove organic pollutants from the ground due to metabolic breakdown.
- These hyperaccumulator species naturally occur in many parts of the world including the Mediterranean region, tropical South America.
Advantages of phytoremediation with hyperaccumulators
- It is cost-effective compared with other remediation methods.
- The method is simple and doesn’t require any new kinds of specialised technology.
- No external energy source is required.
- It enriches the soil with organic substances and microorganisms.
- Protect the soil from erosion due to wind and water.
Disadvantages of phytoremediation with hyperaccumulators
- It is a very slow and time-consuming process.
- Large economic cost due to the inability to grow crops on the remediation land.
- Hyperaccumulator plants chosen to conduct the rehabilitation could act as invasive species, growing out of control and disturbing the fragile ecological balance.
Different types of Phytoremediation Processes
- Rhizosphere biodegradation: The process includes plants releasing natural substances through their roots, supplying nutrients to microorganisms in the soil. The microorganisms enhance biological degradation.
- Phyto-stabilization: In this process, chemical compounds produced by the plant immobilise contaminants, rather than degrade them.
- Phyto-extraction: In this process, plant roots absorb the contaminants along with other nutrients and water. The contaminant mass is not destroyed but ends up in the plant shoots and leaves.
- Rhizofiltration: The process is similar to phyto-accumulation but the plants used for cleanup are raised in greenhouses with their roots in water. Phyto-volatilization: In this process, plants take up water containing organic contaminants and release the contaminants into the air through their leaves.
- Phyto-degradation: In this process, plants actually metabolize and destroy contaminants within plant tissues.
- Hydraulic Control: Plant indirectly remediate by controlling groundwater movement. They act like natural pumps wherein their roots establish a dense root mass that takes up large quantities of water.
Source: IE
Previous article
Guidelines for Safety Assessment of Genome Edited Plants, 2022
Next article
Olive Ridley Turtle