Treatment effect of rural domestic sewage by aerated biological purification pond: taking Shangcheng County in southern Henan Province as an example

In order to improve the stability of rural domestic sewage treatment and meet the demand of ecological landscape construction, aeration biological purification pond (ABPP) technology was put forward which is the conbined mechnism of high-adjusted ablity of stabilization pond technology, suitable for low concentration organic wastewater treatment of contact oxidation method and steady state of grass shallow lakes. The new process was applied to treat rural domestic sewage in 11 towns and districts of Shangcheng County in southern Henan Province, and the operating effects of 4 typical cases for one year were summarized. The results showed that the pollutant concentration of domestic sewage was low and fluctuated greatly due to the confluence drainage system, the rainy climate characteristics in southern Henan and the habits of residents using septic tank sewage to irrigate vegetable gardens. The ABPP had the long hydraulic retention time and completely mixed-sewage, forming bacteria-grass coexisted water steady state system which is suitable to purify the low concentration pullution. Chemical oxygen demand (COD_Cr), ammonia (NH₃-N), total nitrogen (TN), total phosphorus (TP) in the effluent reach Level 1 standard of the Rural Sewage Treatment Facilities of Water Pollutant Discharge Standard (DB41/1820-2019), COD_Cr and NH₃-N meet Grade Ⅳ or above quality standard of the Environmental Quality Standards for Surface Water (GB 3838-2002). ABPP is the appropriate process to treat rural domestic sewage with low pollutants, and benefit to improve the rural water ecological landscape.