Mechanism of Removal of Contaminants by Aquatic Plants

Abstract

Plants possess highly specific and efficient mechanisms to acquire essential micronutrients from the environment. Uptake and removal of contaminant varies for each category of aquatic macrophyte i.e. free-floating, submerged and emergent. The mode of uptake by plants is also different for organic and inorganic contaminant. Uptake of inorganic compounds (ionic or complexed form) is mediated by active or passive uptake mechanisms within the plant, whereas uptake of organic compounds is generally governed by hydrophobicity (log k ow) and polarity. Uptake of pollutants by plant roots is different for organic and inorganic compounds. Uptake of inorganic contaminants is facilitated by membrane transporters, while uptake of organic contaminants is driven by simple diffusion based on their chemical properties. Assimilated and absorbed contaminant is then transformed and detoxified by a variety of biochemical reactions in the plant system using versatile enzymatic machineries.