Green small technology for neighbourhood regeneration: a southern case-study.

The issue of Municipal Solid Waste production can be converted into a development opportunity if the disposal paradigm is substituted by the management concept that is inspired to criteria of resource usage optimization. The MSW management can be optimized in order to reduce fresh raw materials and energy usage and to reuse/recycle of waste materials. Mostly, the treatment of biodegradable waste can be considered an important resource to produce high quality compost, biogas, heat and electricity. Within complex metropolitan areas, the neighbourhood scale, which is explored by the present research, can be considered as the basic spatial unit of interrelation. At the neighbourhood scale, in fact, the community can be easily involved and the “proximity principle” (which is invoked by a correct MSW management) can be efficiently implemented as well as the paradigm of self-sufficient energy can be more easily applied. Particularly, the suburban neighbourhoods represent fertile experimental cases where the projects of ecological infrastructures and of plants for the waste recycling and the energy recovering can become strategic opportunities to drive more sustainable actions of urban regeneration. Within this framework, the marginal and incomplete conditions of suburbs can be interpreted as occasions for new projects of sustainable development, with more degrees of freedom than central urban areas where the level of building density is higher. The paper proposes the implementation of an innovative and small size technology for the treatment of biodegradable waste materials with anaerobic bio-digester. It is a reproducible and scalable design and it is suitable to satisfy the neighbourhood instances. Through the collection of direct data, and the elaboration of the indirect ones that complete the qualitative and quantitative framework, the feasibility verification has been conducted. The comparison of three alternative scenarios has been allowed to make the cost-benefit analysis and to evaluate the production of renewable energy, the reduction of greenhouse gas emission and the energy consumption saving, with reference to Kyoto protocol objectives for the year 2020. The applicative aspects of the proposal have been developed in an emblematic neighbourhood case study: the public housing of Borgo Ulivia on the fringes of Palermo, in comparison with the metropolitan context and the pressing need to face the MSW management crisis in harmony with correct actions of urban regeneration.