High-strength domestic wastewater treatment using Epipremnum aureum as the cathodic plant in a constructed wetland-microbial fuel cell

Constructed wetlands (CWs) and microbial fuel cells (MFCs) are efficient and cost-effective methods for wastewater treatment. This study utilized a novel coupled CW-MFC system employing a ceramic separator to treat domestic wastewater with a chemical oxygen demand (COD) range of 200-800 mg/L and a hydraulic retention time (HRT) of 12-24 h. The novelty lies in the use of Epipremnum aureum as a floating macrophyte in the anode chamber and as a cathodic plant, eliminating the need for external aeration and enhancing overall system performance. This plant was selected for its high radial oxygen loss, adaptability to aquatic environments, and ability to improve COD and nutrient removal efficiencies. Dolochar was employed as an adsorbent to achieve phosphorus and non-biodegradable organic removal. The maximum COD RE of 94 % and power density of 4.9 W/m3 (COD-200 mg/L, HRT-24 h) were observed in the CW-MFC. With cathodic plants in the cathodic compartment, NH4+, NO3- , and TN removal were 81.5 %, 56.9 %, and 72.9 %, respectively, with a PO4 3-removal of 42%. NO3 -removal doubled, and PO4 3-removal increased 2.2 times with cathodic plants. Phosphorus removal after adsorption reached a maximum of 66 %, and COD removal increased to 94.6 %. The coupled CW-MFC system demonstrated high efficiency in COD removal, power generation, and nutrient removal, making it promising for sustainable wastewater treatment.