Phytoremediation meaning ‘plant’ and Latin remedium, meaning ‘restoring balance’ refers to the technologies that use living plants to clean up soil, air, and water contaminated with hazardous contaminants. It is defined as “the use of green plants and the associated microorganism, along with proper soil amendments and agronomic techniques to either contain, remove or render toxic environmental contaminants harmless”.
Phytoremediation is a cost-effective plant-based approach of remediation that takes advantage of the ability of plants to concentrate elements and compounds from the environment and to metabolize various molecules in their tissues. It refers to the natural ability of certain plants called hyperaccumlators to bioaccumulate, degraded or render harmless contaminants in soils, water, or air, Toxic heavy metals and organic pollutants are the major targets for phytoremediation. Knowledge of the physiological and
molecular mechanisms of phytoremediation began to emerge in recent years together with biological and engineering strategies designed to optimize and improve phytoremediation. In addition, several field trials confirmed the feasibility of using plants for environmental cleanup.
Phytoremediation may be applied wherever the soil or static water environment has become
polluted or is suffering ongoing chronic pollution. Examples where phytoremediation has been
used successfully include the restoration of abandoned metal mine workings, and sites where polychlorinated biphenyls have been dumped during manufacture and mitigation of ongoing coal mine discharges reducing the impact of contaminants in soils, water, or air. Contaminants such as metals, pesticides, solvents, explosives, and crude oil and its derivatives, have been mitigated in phytoremediation projects worldwide.
Many plants such as mustard plants, alpine pennycress, hemp and pigweed have proven to be successful at hyperaccumulating contaminants at toxic waste site.
Not all plants are able to accumulate heavy metals or organics pollutants due to differences in the physiology of the plant. Even cultivars within the same species have varying abilities to accumulate pollutants.
Over the past 20 years, this technology has become increasingly popular and has been employed at sites with soils contaminated with lead, uranium, and arsenic. While it has the advantage that environmental
concerns may be treated in situ, one major disadvantage of phytoremediation is that it requires a long term commitment, as the process is dependent on a plant’s ability to grow and thrive in an environment that is not ideal for normal plant growth.