Emergy Analysis of Typical Decentralized Rural Sewage Treatment System: A Case Study of Soil Rapid Infiltration in Qingdao, China

Abstract: Decentralized sewage treatment systems are commonly used in rural areas of China because these systems are low cost, easy maintenance and high efficiency. However, as awareness of the importance of sustainable development has increased, questions concerning how to evaluate the sustainability of these systems has become a key point. In this study, emergy analysis is applied to evaluate the soil rapid infiltration for a decentralized rural sewage treatment plant that is located in Dongzhuangtou village, Qingdao, China. The results show that the environmental load ratio and the emergy sustainability index of the system are 0.07 and 242.88, respectively. The net economic benefit is 2.17E+18 sej·year-1 when converted into solar emjoule. Compared to other treatment systems, the environmental load ratio of the system is lower, and the emergy sustainability index is higher. This study reveals the reuse of treated water can produce great economic benefits in the soil rapid infiltration system. The enviro...