Question

You are working in an area that has been contaminated by heavy metals, what plant-based strategy will you try to remediate the soil so that you can later create a park?

Answer 1

Ans: The plant based strategy we can use for degradation of heavy metals contaminants is Phytoremediation.

Phytoremediation is a bioremediation process that uses various types of plants to remove, transfer, stabilize, and/or destroy contaminants in the soil and groundwater.

There are three mechanisms of Phytoremediation one of them is phytoextraction.

Phytoextraction (or phytoaccumulation or phytosequestration) exploits the ability of plants or algae to remove contaminants from soil or water into harvestable plant biomass. The roots take up substances from the soil or water and concentrate it above ground in the plant biomass.Organisms that can uptake high amounts of contaminants are called hyperaccumulators. Phytoextraction can also be performed by plants (e.g. Populus and Salix) that take up lower levels of pollutants, but due to their high growth rate and biomass production, may remove a considerable amount of contaminants from the soil. At the time of disposal, contaminants are typically concentrated in the much smaller volume of the plant matter than in the initially contaminated soil or sediment. After harvest, a lower level of the contaminant will remain in the soil, so the growth/harvest cycle must usually be repeated through several crops to achieve a significant cleanup. After the process, the soil is remediated.

Second Mechanism is Rhizosphere biodegradation.

In this process, the plant releases natural substances through its roots, supplying nutrients to microorganisms in the soil which enhances the growth of those microbes which are able to digest these heavy metals.

Third and the last mechanism is Phyto-stabilization.

In this process, chemical compounds produced by the plant immobilize contaminants, rather than degrade them. So these heavy metals do not pollute a large surface area but limited by a small area.