Anaerobic Tank-Subsurface Flow Constructed Wetland System for Rural Domestic Wastewater Treatment
厌氧池-潜流人工湿地处理低浓度农村生活污水的研究

An Anaerobic Tank-Subsurface Flow Constructed Wetland (AT-SFCW) System for treating rural domestic wastewater was studied in removal efficiency and mechanism for Chemical Oxygen Demand (COD), nitrogen and phosphorus in Xuedian Village, Xinzhuang Town of Changshu City. The AT part, which compared with SFCW, was also studied for explaining the functions of AT-SFCW System. The results showed that this system could remove 44.3%, 42.7%, 73.9%, 45.6% and 37.5% of COD, TN, TP, NH3-N and NO3-N respectively, and the effluent concentration were 16.9, 5.2, 0.1, 3.3 and 1.4 mg/L for COD, TN, TP, NH3-N and NO3--N respectively, which were below the national discharge standard of pollutants for municipal wastewater of Class A level (GB18918-2002). The AT part could remove 17.4%, 6.7% and 57.7% of COD, TN and NO3--N respectively, but the concentrations of TP was increased by about 15.3%. The removal efficiency of SFCW part for TP, NH3-N, TN and CODcr were 89.2%, 44.5%, 36.0% and 26.9% respectively, so this part played a more important role in removing pollutants. Hence, AT-SFCW system is very effective in treating rural domestic wastewater, it is also material/energy-saving compared with central technical systems, thus, worth popularization and application.