Industrial Symbiosis for a Sustainable City: Technical, Economical and Organizational Issues

In this paper, we propose the adoption of industrial symbiosis approach within cities as a tool to improve their environmental sustainability. In particular, organic waste can be used to produce electric energy required by cities. In this way, a resource closed loop is generated, able to reduce the amount of waste disposed of in landfill and the energy purchased from outside the city. We develop a conceptual model that identifies symbiotic flows and processes that generate and receive them. We model these processes using the input-output approach. An efficiency measure of the symbiotic approach within urban areas has been proposed. Finally, we employ three case examples in order to show how the model works. As a result, we provide some useful managerial suggestions for policy makers about the implementation of industrial symbiosis within cities.