The removal of pharmaceuticals ibuprofen and naproxen from natural wastewater by subsurface vertical flow constructed wetlands

Constructed wetlands efficiently remove pharmaceuticals from wastewater. The removal efficiency of ibuprofen and naproxen was examined in an experimental subsurface vertical flow constructed wetland using 1, 2, and 4-day hydraulic retention times (HRT). Pharmaceutical removal and HRT were not correlated. Ibuprofen concentrations were positively correlated with naproxen concentrations in influent and effluent waters. Low influent concentrations (<16.0mug/L) of ibuprofen and naproxen showed either low or negative removal efficiencies. Moderate influent concentrations (16.0mug/L-31.0mug/L) showed the highest removal efficiency, with an average of 44% and a high of 82%. Removal efficiencies decreased at higher influent concentrations. Pharmaceutical removal was examined at a municipal wastewater treatment plant using both sequential batch reactor and working constructed wetlands. Both were efficient in removing pharmaceuticals in-situ at efficiencies of 83%-99%. While multiple variables impact the removal of pharmaceuticals from wastewater, constructed wetlands offer viable alternatives to conventional processes for pharmaceutical removal.