**2. Phytoremediation: a bio-decontamination approach**

The concept of extraction of metals by macrophytes was actually given by Chaney [11]. Efficiency of macrophytes to extract metals from contaminated site depends on the metal hyperaccumulation capacity and biomass production. The selection of particular plant species for phytoremediation depends on the following characteristics:

i.native to the particular ecosystem.

ii.well flourishing nature and high biomass yield.

iii. ability to uptake large amount of metals.

iv.transportation of metals to aboveground plant portion.

v.mechanism to tolerate metal toxicity.

In addition, factors like pH, light intensity and nutrient availability influences the plant growth and thus, phytoremediation potential [12–16]. Agronomic practices for soil and crop management and improved genetic engineering technologies to enhance metal tolerance and translocation can affect the remediation mechanism. Exsituas well asinsitu methods of phytoremediation are there:*exsitu method* involves excavation of contaminated soil followed by its treatment and also shifting the soil for land filling;*insitu method* is less laborious and more cost effective and commonly employs mechanisms like phytoextraction and phytostabilization [17].

*Aquatic Plants as Bioremediators in Pollution Abatement of Heavy Metals DOI: http://dx.doi.org/10.5772/intechopen.99627*
