Phytoremediation is a process that uses plants to remove contamination from soil, water or sediments. It works by utilizing the natural biological, chemical and physical processes of plants. Plants can absorb, break down, stabilize or prevent the spread of contaminants like heavy metals, pesticides and organic pollutants. Some common plants used for phytoremediation include alfalfa, poplar trees, and bermuda grass. The advantages are that it is a low-cost, environmentally friendly way to treat large areas of land. However, it is a slower process and not effective for high concentrations of contamination.