Abstract: Eco-exergy is defined as the amount of work that a system can perform when the system is brought into thermodynamic equilibrium from a given state. It can be used to measure the complex biochemical components and ecological structure. A system with more exergy will present better ordering and stability. Eco-exergy and specific eco-exergy can be used to assess the status of aquatic ecosystem health, and indicate the certain succession stage in aquatic ecosystem restoration. This paper presented the definitions and ecological meanings of eco-exergy and specific eco-exergy as well as the calculation methods of eco-exergy and weighting factor f_i, summarized the applications of eco-exergy as a goal function in structural dynamic models (SDMs) and as an ecological indicator for ecosystem health assessment and ecological restoration of aquatic ecosystems, and discussed the limitations and future development of eco-exergy. Furthermore, the unified translation of “eco-exergy” and “specific eco-exergy” in Chinese was suggested.

Key words: Combined flocculants, Flocculent performance, Turbidity, Sewage treatment, Ecological safety