Phytoremediation is a natural process that uses plants to remove contaminants from soil and water. It involves using plants and their associated microorganisms to degrade, extract, and stabilize pollutants in the environment. The document discusses the various methods of phytoremediation including phytoextraction, rhizofiltration, phytovolatilization, phytostabilization, and phytotransformation. It also provides examples of plant species commonly used for different phytoremediation processes and contaminants removed.