What are the ways of phytoremediation? What are their respective roles?

The methods of phytoremediation include plant extraction, plant degradation and plant stabilization. Plant extraction refers to the use of plants to absorb and accumulate pollutants and treat them after harvest. Harvesting can be carried out by heat treatment, microbial treatment and chemical treatment. Plant degradation is the use of plants and related microbial flora to transform pollutants into non-toxic substances.