Performance of polyculture constructed wetland compared with monoculture in treating domestic wastewater

This study aimed to determine the performance of polyculture constructed wetlands compared with monocultures and to monitor plant type influence in treating wastewater. Four pilot scales were used and planted with three plant kinds (Phragmites Australis, Cyperus Papyrus, and Scirpus). Three of them were monoculture systems, and the last one was a polyculture system with all these plants. The filters had identical sizes and the same density. After seven days of retention time, results showed that the pH obtained was around neutral ranging from 6.91 to 7.32; the electrical conductivity increased significantly and it was between 4.47-5.47 mS/cm. Removal efficiencies of phosphate, ammonium, nitrite, and chemical oxygen demand were between 75.29-79.90%, 91.27-92.51 %, 83.33-86.32%, and 84.61-88.52%, respectively. Papyrus filter had the higher removal efficiencies in most of these parameters, and the polyculture system didn’t increase the filter performance; however, the differences between these filters were not significant, except for the electrical conductivity.