5. Phytoremediation Strategies on Heavy Metal Removal

Over many decades, treatment and reuse of wastewater has been a key research area for environmentalists. Scientists have succeeded in the usage of wastewater for agricultural purposes. However, the discharge of effluent from the industries led to a constant increase in effluent concentration and adversely affects the health of human, plants, and animals. Phytoremediation is one of the wastewater treatment technologies used to eradicate the contaminants from marine and soil environment without disturbing the environment. The ability of plants roots to accumulate, translocate, and degrade the contaminants from environment plays a major role in phytoremediation process. Phytoremediation follows mainly five mechanisms which are phytoextraction, phytostabilization, phytodegradation, phytovolatilization, and phytofiltration. Aquatic or terrestrial plants are used to accumulate, immobilize, or degrade the contaminants from air, soil, and water. It is an inexpensive technique and it could be applied to large contaminated areas without any significant damage to environment. Treatment of contaminated site would take long period is one of the few limitations to overcome. Chelating agents are used to enhance the accumulation ability of plants. Inorganic chelating agents are more aggressive and enhance high accumulation of contaminants. To protect the environment and to enhance the accumulation ability of plant, organic acids are used as chelating agents. The success of phytoremediation is determined not only by accumulation ability but also by the bioavailability of contaminants in environment and plant. This chapter discusses the potential mechanisms and strategies available to widen the application of phytoremediation.