Combined Process of Trickling Filter and Constructed Wetland for Rural Domestic Wastewater Treatment

The combined process of trickling filter and constructed wetland was developed to meet the requirements of higher efficiency,lower energy consumption,easier management in rural domestic wastewater treatment,and an experimental study was conducted to investigate the optimal operation parameters of trickling filter and the measures for improving phosphorus and nitrogen removal.The results show that it is feasible to use this process in treating rural domestic wastewater,and the average removal rates of COD,NH+4-N,TN and TP are 73.6%,89.5%,61.7% and 78.4% respectively.The operation cost is 0.23 Yuan/m3.The volume loading,hydraulic loading,reflux ratio and sprinkling period of the trickling filter should be controlled at 0.3 to 0.5 kgCOD/(m3·d),less than 4.0 m3/(m2·d),2.0 and 20 min respectively.