Efficiency of Constructed Wetlands with Indigenous Umbrella Sedge for Rural Domestic Wastewater Treatment in Northern Vietnam

: Plants plays a crucial role in the treatment mechanisms of constructed wetlands (CW). In this study, the indigenous umbrella sedge (Cyperus alternifolius) was employed for the treatment of rural domestic wastewater in northern Vietnam, a region characterized by a tropical monsoon climate. The CW system was designed with a planting density of 105 plants/m² on a substrate composed of gravel, stones, and sand. The experiment was conducted over a period of 60 days, with a wastewater inflow of 100 L/day and sampling performed every three days. The results indicated that the removal efficiencies of COD, TSS, NH₄⁺, TN, and TP were 67.0 ± 5.5%, 61.7 ± 6.0%, 66.6 ± 8.4%, 71.8 ± 5.8%, and 68.0 ± 10.3%, respectively. The effluent quality consistently met the Vietnamese standard QCVN 14:2025/BTNMT, Column B. These findings highlighted the potential of indigenous plant-based CW systems as an effective and sustainable approach for domestic wastewater treatment in rural areas of Vietnam.