Which contaminant is removable from stormwater runoff through phytoextraction?

Which contaminant is removable from stormwater runoff through phytoextraction?

• A. Zinc
• B. Nitrogen
• C. Phosphorus
• D. Biochemical oxygen demand

Answer: (A)

Phytoextraction is a form of phytoremediation where plants take up contaminants from water or soil and store them in their above-ground tissues, so harvesting the plants physically removes the contaminant from the environment. This works well for metals that plants can accumulate, such as zinc. Zinc is a common metal pollutant in stormwater from urban sources like galvanized surfaces and vehicle wear, and certain plants can accumulate zinc in their shoots. By growing these plants in a treatment system and then harvesting the biomass, the zinc is removed with the plant material. Nitrogen and phosphorus are nutrients that plants also uptake, but they don’t fit the same removal pattern because they’re part of ongoing nutrient cycles and can re-enter the system through mineralization and other processes. Biochemical oxygen demand reflects organic pollution and is addressed mainly by microbial degradation and dilution, not by pulling it out with plant tissue. So zinc is the contaminant removable from stormwater runoff through phytoextraction.

Phytoextraction is a form of phytoremediation where plants take up contaminants from water or soil and store them in their above-ground tissues, so harvesting the plants physically removes the contaminant from the environment. This works well for metals that plants can accumulate, such as zinc. Zinc is a common metal pollutant in stormwater from urban sources like galvanized surfaces and vehicle wear, and certain plants can accumulate zinc in their shoots. By growing these plants in a treatment system and then harvesting the biomass, the zinc is removed with the plant material. Nitrogen and phosphorus are nutrients that plants also uptake, but they don’t fit the same removal pattern because they’re part of ongoing nutrient cycles and can re-enter the system through mineralization and other processes. Biochemical oxygen demand reflects organic pollution and is addressed mainly by microbial degradation and dilution, not by pulling it out with plant tissue. So zinc is the contaminant removable from stormwater runoff through phytoextraction.