Page 727 - e-Book

PHYTOEXTRACTION RHIZOFILTRATION PHYTOSTABILIZATION PHYTOVOLATILIZA
It includes Absorption of Involves the usage of Where Plants are used TION

heavy metals from the for balance in preference Which includes the usage of

soil and their switch to plants to smooth to cleansing up plant life to extract sure metals
from the soil and release them
shoots in which they numerous aquatic contaminated soil into the surroundings through

acquire. transpiration
environment infected
with heavy metals.

PHYTOEXTRACTION: In phytoextraction, Plants absorb metal pollutants and accumulate

them in their shoots, after which shoots are harvested and incinerated. (Salt et al. 1998),
which are harvested and incinerated. The ashes containing the heavy metals are then disposed

off so that risk of spreading of pollution from them decreases. The ashes are then disposed of

in secured sites to prevent further pollution (Blaylock et al. 1997).In this method there is
absorption and switch of heavy metal impurities from the soil a part of the plant roots to the

above floral parts. Hyper accumulator plants accumulate one hundred times more heavy
metals than a non-accumulating plant (Erakhrumen 2007). According to Studies, in Hyper

Accumulator Plants Leaves are the main sinks for metal accumulation. (Psaras and Manetas
2001).Metals along with nickel, zinc and copper are the handiest in eliminating

phytoextraction due to the fact they have been shown to be famous with most plants (about

400) which soak up and absorb an unusually massive quantity of heavy metal. One essential
function located most effective in metallic hyperaccumulators is that a small mixture of

heavy metals is given roots in comparison to leaves and stems (Baker et al. 1994) that is
because of the a success transfer of such metals from roots to shoots and is considered a

beneficial strategy in the tolerance of heavy plants, because the primary target of heavy-
metallic toxicity is the root system (Godbold et al. 1984).The biggest advantage of this

technique is that it is not costly and very effective to remove heavy metals from contaminated

soil.
The Effectiveness of Phytoextraction depends upon: Availability of Metals within the

Rhizosphere,at which rate metal uptake by roots is done, how much concentration of metal is

fixed in roots, at which rate metals are translocate to shoots, and how the plant cells show
tolerance to heavy metals. (Dhir 2013).

RHIZOFILTRATION: In this Process plants are used mainly for contaminated ground
water rather than soil. The plants to be used for removal of heavy metals are grown in

greenhouses with their roots in water rather than in soil. Once a comprehensive root system
of vegetation has been developed, wastewater is accumulated from the polluted area and

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