Efficiency of Cattail to Remove a Mixture of Pharmaceuticals in a Constructed Wetland

Reducing the risk of the aquatic ecosystem's contamination with organic substances such as pharmaceuticals is of great importance due to the toxicological effect of these substances on aquatic organisms. Therefore, the removal of pharmaceuticals and/or their metabolites frequently reported in industrial or municipal wastewaters require efficient processes that complement the conventional treatment systems; the constructed wetlands are an option. In this work, the removal efficiency of mixed diclofenac and naproxen was evaluated using a subsurface flow constructed wetland planted with cattail (Typha latifolia), operated during 100 days at a hydraulic residence time (HRT) of 3 days. Under these conditions, the diclofenac and naproxen removal efficiencies were 82.0% and 74.5%, respectively. The interaction between diclofenac and naproxen with cellulose, which is the major cell wall compound of higher plants, was computationally modeled at the PM6 semi-empirical level of theory and it was found that diclofenac and naproxen interact with cellulose via hydrogen bonds.