Study on the influences of flow modes on wastewater treatment efficiency of sequencing batch constructed wetland

The sequencing batch constructed wetland exhibits a high nitrogen removal efficiency. The influences of intermittent and continuous flow modes of SCW on wastewater treatment efficiency were investigated. The experimental results showed that the influent mode has a significant effect on the removal of TN, while the removal of COD and NH₄⁺-N isn\´t affected remarkably. When temperature is 18°C~25°C, loading is 38gCOD/(m2·d), the domestic wastewater with COD of 306mg/L, NH₄⁺-N of 65mg/L and TN of 73mg/L is treated. By intermittent influent mode and running condition of "10min\´s inlet-12h\´s reaction-10min\´s drainage-4h\´s emptying idle", the effluent concentrations of COD, NH₄⁺-N and TN is 45mg/L, 7mg/L and 19mg/L respectively and removal rate of 85%, 89% and 74% respectively. Compared to continuous flow mode and "inlet-12h\´s reaction-10min\´s drainage-4h\´s emptying idle", the removal rate of COD and TN is increased by 4% and 32% respectively.