● phytoextraction or phytoconcentration: the contaminant is concentrated in the roots, stem and foliage of the plant
● phytodegradation: plant enzymes help catalyse the breakdown of the contaminant molecule
● rhizosphere biodegradation: plant roots release nutrients to micro-organisms which are active in biodegradation of the contaminant molecule
● volatilization: transpiration of organics, selenium and mercury run through leaves of the plant