What is phytoremediation, and how do plants help clean polluted soils?

• A. Phytoremediation uses microbes to degrade pollutants.
• B. Phytoremediation uses chemical oxidants to break down pollutants.
• C. Phytoremediation relies on algae to clean soils.
• D. Phytoremediation uses living plants to stabilize, extract, or degrade pollutants in soil or water.

Answer: (D)

Phytoremediation is a plant-based approach to cleaning polluted soils and water. Plants can help by stabilizing contaminants in place to prevent spread (phytostabilization), extracting pollutants from soil and concentrating them in their tissues (phytoextraction), or breaking down pollutants inside the plant or in the surrounding soil via interactions with root microbes (phytodegradation). Some plants even release contaminants into the air through transpiration (phytovolatilization) or remove contaminants from water through their roots (rhizofiltration). This makes cleanup a more natural, often cheaper and less disruptive option compared to heavy machinery or chemical treatments.

The statement that plants are living organisms used to stabilize, extract, or degrade pollutants in soil or water captures the essence of phytoremediation. Other options rely on microbes, chemical oxidants, or algae, which are not plant-based approaches, so they don’t describe phytoremediation.