Research and demonstration of hybrid constructed wetland technology for domestic sewage treatment in rural resettlement areas in the Three Gorges Reservoir area

Abstract

Based on the investigation of the current situation of domestic sewage treatment in rural resettlement areas in the Three Gorges Reservoir area, aiming at the characteristics of large number of villages, scattered settlements and complex terrain in rural resettlement areas, and aiming at water quality purification and collaborative resource utilization, one rural resettlement residential area was selected in Zigui County in the Three Gorges Reservoir area for demonstration, and applied the ecological and unpowered technology of vertical subsurface flow+horizontal subsurface flow hybrid constructed wetland+water quality control and on-demand discharge to treat domestic sewage.The monitoring results showed that the average removal rates of COD_Cr(chemical oxygen demand), BOD₅(biochemical oxygen demand), TN(total nitrogen), TP(total phosphorus) and NH₃-N(ammonia nitrogen) were 79.11%, 84.51%, 43.42%, 59.71% and 71.89%, respectively. This technology has the advantages of good treatment effect, simple operation and maintenance, no power consumption, low construction and operation cost, and is not limited by the treatment scale and terrain. It is suitable for the treatment of domestic sewage in residential areas with a population of 50~200 people in the mountainous area, and provides technical reference and case reference for the ecological treatment and resource utilization of rural domestic sewage in the Three Gorges Reservoir area.

Keywords

Three Gorges Reservoir area / rural resettlement area / rural domestic sewage / ecological treatment / hybrid constructed wetland