Performance of Integrated Bioreactor Treating Rural Domestic Sewage in Karst Area

Vertical A²/O technology was applied in a rural sewage treatment plant with the designed capacity of 1 000 m³/d. The device integrated anaerobic treatment, anoxic treatment, aerobic treatment, precipitation and other processes. There was no mixed liquid reflux pump in the integrated device, and sludge returned naturally through gravity. The newly integrated bioreactor system was operated successfully for 9 months with good performance and high removal efficiency of pollutants. The average removal efficiencies of COD, NH₄⁺ - N, TN, and TP were 78.39%, 88.36%, 80.16% and 72.75%, respectively. The quality of the effluent could meet the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant(GB 18918-2002). The newly integrated bioreactor had compacted structure, convenient operation and satisfactory effluent quality, which was suitable for the treatment of rural domestic sewage.