Theory and control mechanism of eco-industrial parks
生态工业园区生态系统理论及调控机制

Following the development of Industrial Ecology (IE) and the widespread promotion of Circular Economy (CE), Eco-Industrial Parks (EIPs) have been rapidly developed throughout the world. An EIP is a district where enterprises are organized according to industrial symbiosis and Circular Economy. It aims to optimize the integrated benefits of environment, economics, and society in the park. However, there is a limited understanding of EIP ecosystematic structure, function and optimized control mechanism. As a result, almost all the present EIPs are inappropriately designed as a closed loop or network to merely recycle waste. This is especially true in China. Unfortunately, such a narrow thinking of EIPs, deeply embedded in decision-makers' mind, has already imposed significant impacts in the development of EIPs in China. This research tries to raise the question and establish the theory of analyzing and optimizing EIP ecosystem. The paper analyzes the ecosystem characteristics of EIP. It illustrates the importance of technology and knowledge in EIP ecosystem. It also demonstrates that the conventional theory of complex ecosystem cannot explain ecosystem function in EIPs. Based upon the above analysis, the research proposes a comprehensive ecosystem structure for EIPs. This structure is built upon the following four sub-ecosystems: society, environment, economics, and resources. The paper then provides a theoretic curve that illustrates the interaction among coordinating degree index, coordinating cost, and ecosystem benefits. The results show that the coordinating cost first increases moderately while the coordinating degree increases. When the coordinating degree reaches a certain point, the cost increases dramatically. In addition, the paper analyzes the flows of materials, energy, information, value, technology, and knowledge from the perspective of ecosystem function. It also provides indicators and formula for calculating the flows. At the same time, the authors provide an optimal control mechanism of ecosystem management. On the basis of green business recruiting (GBR) and green supply chain management (GSCM), the proposed mechanism integrates point and process control principles of Green Supply Chain into EIP management systems. In the end, the research provides a case study of Singapore-China Suzhou Industrial Park.