Abstract

Phytoremediation is the use of plants to extract, sequester or mineralize pollutants. This process is seen as an ecologically sound strategy for management of contaminated ecosystems. In this review, current status of several subsets of phytoremediation are discussed which includes: (a) Phytoextraction – which is a process in which high biomass pollutant accumulating plants are used to accumulate and transport pollutants from the soil to harvestable parts of plants. (b) Phytofiltration – which is a process in which plant roots are used to precipitate and concentrate pollutants from effluents. (c) Phytostabilization - here plants stabilize pollutants, thus rendering them harmless. (d) Phytovolatilization –plants absorb pollutants and convert them into gaseous components via transpiration. The advantages inherent in these technologies are also discussed. There is need for further understanding on the processes that affect pollutant availability, rhizosphere processes, pollutant uptake and sequestration.  

Key words:  Phytoremediation, xenobiotics, metal, pollution, decontamination.

Abbreviation

PCBs, Polychlorinated biphenyls; PAHs, polycyclic aromatics hydrocarbons; TNT, trinitrotoluene; TCE, trinichoroetoluene; SC, selenium; VOC,volatile organic compounds;  MTs, metallothioneins; PCs, phytochelatins; R-SH,organic sulphur;  CEC, cations-cation exchange capacity; EDTA, ethylene diamine tetra acetic acid; TSCF, transpiration stream concentration factor; SeCys,selenoaminoacids selen-cysteine; SeMet, selenomethionine; DMSe,dimethylselenide; MerA, mercury reductase.