This document discusses different types of phytoremediation including phytodegradation, phytovolatilization, and phytoextraction. Phytodegradation involves plants breaking down organic pollutants like herbicides through enzymes and metabolizing them. Phytovolatilization uses plant evapotranspiration to convert pollutants like VOCs into gaseous forms. Phytoextraction uses hyperaccumulator plants to absorb and concentrate heavy metals in their biomass above ground. The document provides examples of each type and discusses plants used in phytoremediation as well as advantages like being environmentally friendly and disadvantages like processes being slow.

1. PHYTOREMEDIATION –
Phytodegradation, Phytovolatilization,
Phytoextraction
BY,
SHAHIN M
22ENVA17

2. INTRODUCTION
• Phytoremediation is a cost-efficient plant-based approach that takes advantage of the
ability of plants to concentrate elements and compounds from the environment and
metabolize various molecules in their tissues.
• It refers to the natural ability of certain plants to bioaccumulate, degrade, or render
harmless contaminants in soil, water, or air.
• Toxic heavy metals and organic pollutants are the targets for phytoremediation
• Along with being a cost-effective method for environmental redressal, Phytoremediation
has also proven to be a super solution in meeting any form of environmental challenges

3. TYPES OF PHYTOREMEDIATION
• Compared to physical, chemical, and microbiological treatment procedures,
phytoremediation is a highly special pollution control technique.
• A low-cost and effective way to remove pollutants and contaminants from the soil, air,
and water is through phytoremediation
• There are various types of phytoremediation
– Phytodegradation
– Phytovolatilization
– Phytoextraction
– Rhizofiltration
– Phytostabilization

4. Types of
Phytoremediation

5. PHYTODEGRADATION
• Phytotransformation, also known as phytodegradation, is the transformation of organic pollutants
from soil, sediments, or water into a more stable, less hazardous, and less mobile form.
• The plant roots secrete enzymes that break down the organic chemicals, which are subsequently
taken in by the plant and expelled by transpiration.
• Herbicides, trichloroethylene, and methyl tert-butyl ether are among the organic pollutants that
this method works best with.
• The chemical change of environmental compounds as a direct result of plant metabolism is known
as phytotransformation, and it frequently results in their inactivation, degradation
(phytodegradation), or immobilization (phytostabilization).

6. PHYTODEGRADATION
• Organic pollutants, such as pesticides, explosives, solvents, industrial chemicals, and
other xenobiotic compounds, are rendered non-toxic by the metabolism of certain plants,
such as Cannas.
• In other cases, these compounds may be metabolized in soil or water by microbes living
in close proximity to plant roots.

7. PHYTOVOLATILIZATION
• Phytovolatilization involves the uptake of contaminants by plant roots and its conversion
to a gaseous state, and release into the atmosphere.
• This process is driven by the evapotranspiration of plants. Plants that have high
evapotranspiration rate are sought after in phytovolatilization.
• Organic contaminants, especially volatile organic compounds (VOCs) are passively
volatilized by plants.
• For example, hybrid poplar trees have been used to volatilize trichloroethylene (TCE) by
converting it to chlorinated acetates and CO2. Metals such as Se can be volatilized by
plants through conversion into dimethylselenide [Se(CH3)2].

8. PHYTOVOLATILIZATION
• Genetic engineering has been used to allow plants to volatilize specific contaminants.
• For example, the ability of the tuliptree (Liriodendron tulipifera) to volatilize methyl-Hg
from the soil into the atmosphere (as Hg0) was improved by inserting genes of modified
E. coli that encode the enzyme mercuric ion reductase (merA).

9. PHYTOEXTRACTION
• Phytoextraction / phytoaccumulation is the process by which plants accumulate
pollutants in their roots, shoots, or leaves above ground.
• The roots absorb elements from the soil or water and concentrate them in the plant
biomass above ground.
• Hyperaccumulators are organisms that have a high capacity for absorbing pollutants.
• For the past twenty years or so, phytoextraction has been rapidly gaining popularity
around the world. Heavy metals and other inorganics are commonly extracted via
phytoextraction.
• Contaminants are often concentrated in a significantly smaller volume of plant matter at
the time of disposal than in the initially contaminated soil or silt.

10. PHYTOEXTRACTION
• Because a lesser level of pollutant remains in the soil after harvest, the growth/harvest
cycle must normally be repeated over several crops in order to achieve a meaningful
cleanup. The soil is then remediated as a result of the procedure.

11. TYPES OF PLANTS USED IN PHYTOREMEDIATION
• Indian Mustard
• Hyacinth
• Willow
• Duckweed,
• Poplar Tree
• Azolla
• Indian Grass
• Cattail
• Sunflower

12. ADVANTAGES
• Environmental Friendly Option: It is an environmentally friendly approach as it can limit
pollution exposure to the environment and ecosystem.
• Applicability And Easy Disposal: This method can be applied over a large-scale field and
easily disposed of.
• Prevents Erosion And Spreading: It prevents erosion and metal leaching by stabilising
heavy metals, reducing the risk of contaminants spreading.
• Improve Soil Fertility: It can also improve soil fertility by releasing various organic matter
to the soil.

13. Phytoremediation In Barren Rare-earth Mineral Mined
Site

14. DISADVANTAGES
• Relocation And Not Removal: Phytoremediation relocates hazardous heavy metals rather than
removing them from the environment.
• Limited Scope: The surface area and depth occupied by the roots are the only areas where
phytoremediation can occur.
• Slow Growth And Limited Biomass: Because of the slow growth and limited biomass, a long-
term commitment is required.
• Cannot Totally Avoid Pollutants: It is impossible to totally avoid pollutant leaching into
groundwater using plant-based remediation techniques.
• Impact On Plant Survival: The toxicity of contaminated land and the general quality of the soil
have an impact on plant survival.
• Metal Bonding to Organic Stuff: When taking up heavy metals, the metal might become
bonded to the organic stuff in the soil, making it impossible for the plant to remove.

15. APPLICATIONS
• Soil And Water: Phytoremediation is typically used in stable contaminated soil or aquatic
ecosystems.
• Abandoned Mine Sites: Restoration of abandoned metal mine workings and sites where
polychlorinated biphenyls were deposited during the manufacturing process, as well as
mitigation of active coal mine, discharges decreasing the impact of contaminants in soils,
water, or air, are just a few examples.
• Pesticides, Crude Oil And Derivatives: Metals, pesticides, solvents, explosives, and crude
oil and its derivatives have all been reduced through phytoremediation operations around
the world.
• Toxic Waste Sites: Many plants, including mustard, alpine pennycress, hemp, and
pigweed, have demonstrated their ability to hyperaccumulate toxins at toxic waste sites.

16. CONCLUSION
• In phytoremediation, heavy metal detoxification is a necessary step in the
phytoremediation process.
• Plants thus employ one of two defense methods to deal with heavy metal toxicity:
avoidance or tolerance.
• Plants use these two methods to keep heavy metal concentrations in their cells below the
toxicity threshold levels.
• Through a variety of mechanisms such as root adsorption, metal ion precipitation, and
metal exclusion, it acts as the first line of defense at the extracellular level.

17. THANK YOU