Removal of 17α-ethynylestradiol and β-estradiol using bench-scale constructed wetlands.

Aquatic ecosystems have been devastated by the continued persistence of the synthetic estrogen compounds β-estradiol and 17α-ethynylestradiol. Common wastewater treatment methods do not reduce these compounds in effluent below problematic concentrations. An emerging cost-effective solution to this problem is the use of constructed wetlands to remove these estrogen compounds. This study analyzed the ability of duckweed (Lemna minor), water hyacinth (Eichhornia crassipes), and water cabbage (Pistia stratiotes) to remove β-estradiol and 17α-ethynylestradiol through the use of bench-scale constructed wetlands over a 15-week period. Estrogen concentration in water was collected over time along with plant nutrient content, contaminant extractions, and media extractions. Results indicated that estrogen concentration was reduced by the plants and soil media. Duckweed was the most effective at 96% removal, followed by water hyacinth at 72% removal, then water cabbage at 35% removal, and lastly sediment media at 9% removal. This study provides evidence for the ability of constructed wetlands to be used as a means to remove estrogen compounds from wastewater and demonstrates differences in plants removal efficiencies, with duckweed being the most effective of the selected plants.