Impact of the electrode, aeration strategies, and filler material on wastewater treatment in tidal flow wetlands

The present work reports the pollutants removal performance of the waste material-based non-aerated, intermittently, and continuously aerated normal and electrode-integrated tidal flow wetlands that received municipal wastewater. The tidal flow wetlands were operated under variable wastewater contact periods. The mean biochemical oxygen demand (BOD), ammonium-nitrogen (NH4-N), total nitrogen (TN), total phosphorus (TP), and coliform removal percentage ranges were 74-99 %, 58-87 %, 65-85 %, 62-93 %, and 56-96 %, respectively. Nutrient removals declined in all tidal flow wetlands during the longest wastewater contact period. An opposite trend was observed with organic and coliform removals. The aerated tidal flow wetlands achieved better organic and nutrient removal than the non-aerated systems. Nutrient accumulation percentage in plant tissues ranged between 0.01 and 0.7 %. Power density production within the electrode-integrated tidal flow wetlands ranged between 4474 and 8199 mW/m3. This study demonstrates the necessity of external aeration to improve the performance of the normal and electrode-integrated tidal flow wetlands.