Phytoremediation is an emerging bioremediation technology that uses the plant to remove contaminants from soil and water. It designates all vegetation based remediation measures. A plant has a potential for accumulating, immobilizing, and transforming a low level of persistent contaminants. In natural ecosystems, plants act as filters and metabolize hazardous substances.
Types of phytoremediation
Phytoextraction or Phytoaccumulation
Phytoextraction or phytoaccumulation is the process whereby the plants accumulate contaminants into the roots and shoots. This technique saves cost by accumulating low levels of contaminants from a widespread area.
Phytotransformation or Phytodegradation
Phytotransformation or phytodegradation refers to the uptake of organic contaminants from soil, sediments, or water and, subsequently, their transformation to more stable, less toxic, or less mobile form. Metal chromium can be reduced from hexavalent to trivalent chromium, which is a less mobile and non-carcinogenic form.
Phytostabilization is a technique in which plants reduce the mobility of contaminant and migration of pollutants in contaminated soil. Leachable constituents are adsorbed and bound into the plant’s structure so that they form a stable mass of plant.
Phytodegradation or Rhizodegradation
Phytodegradation or rhizodegradation is the breakdown of contaminants through rhizosphere activity. This activity is due to the presence of proteins and enzymes produced by the plants or by soil organisms such as bacteria, yeast, and fungi.
Rhizofiltration is a water remediation technique that involves the uptake of contaminants by plant roots. Rhizofiltration is used to reduce contamination in natural wetlands and estuary areas
Phytovolatilization is to the uptake and transpiration of soil, water or plant contaminants, by plants. The contaminant, present in the water taken up by the plant, passes through the plant or is modified by the plant, and is released to the atmosphere (evaporates or vaporizes).