## 5 Conclusions  
The present research revealed the interest in incorporating data obtained from anaerobic co-digestion optimization and innovation processes (laboratorial scale) into the local territorial reality dynamics in the development of biogas production units' location and resource allocation scenarios, and implementing effective circular economy models and local sustainable development. The modelling results pointed out that it is possible to set up the location of biogas plants based on resource availability and local biogas yield. Both data and the spatial model enable multidisciplinary approaches, analysis scale changes, actor coordination among the project/planning phases, as well as communication among stakeholders, technicians and the scientific community. The developed spatial model indicates:  
1. A high potential of local bioenergy resources available for biogas production (dairy cattle manure and sewage sludge) and the interest in complementing, at a local scale, the use of existing biogas producing facilities (including those integrated in wastewater treatment plants) with new collective facilities;
2. The suitable locations for the installation of biogas production facilities in low altitude, forested areas, near to cattle farms, the road network and electric injection points, but far from the hydrographic network and avoiding the ecological reserves and protected areas;3. The need to collect and analyze additional and detailed thematic and temporal (e.g., seasonal) data on sewage sludge and animal manure production;
4. The importance of developing multicriteria optimization algorithms to test a set of maximization and optimization functions (location and allocation issues), considering economic and econometric functions and objectives;
5. The reinforcement of multi-objective assessment to compare sites and alternative management models, considering investment and cost analysis. This research has involved collaborative and multidisciplinary tasks in in-field work model validation and future work discussions. Both field collected data and the results of the spatially explicit model are critical to the biogas unit project phase, namely to project technological and constructive solutions within a local social, economic and environmental assessment framework for all and each new potential biogas plant/facility. The results also showed the importance of continuing the development of this spatial model towards a spatial decision support system on a Web-Geographic Information System (WebGIS) platform supporting the planning and future operation of biogas production plants. Experience, data and the spatially explicit model should evolve as a planning, management and governance tool [76]. The integration of the laboratorial data, methods and models into the complex territorial dynamics promotes synergies by contributing to circular economy and the sustainable development of peri-urban communities. Conceptualization, R.D.C., J.M.A., A.C.R., A.I.F., A.G.B. ; methodology, R.D.C., J.M.A., A.C.R., N.M., R.S. ; validation, R.D.C., J.M.A., A.C.R., A.I.F., A.G.B. ; investigation, R.D.C., J.M.A., A.C.R., A.I.F. ; data curation, R.D.C., J.M.A., A.C.R., A.I.F., N.M., R.S. ; writing--original draft preparation, R.D.C., J.M.A., A.C.R., A.I.F. ; writing--review and editing, R.D.C., J.M.A., A.C.R., A.I.F., A.G.B. ; visualization, R.D.C., J.M.A., A.C.R., A.I.F. ; supervision, J.M.A., A.C.R., A.G.B. ; funding acquisition, R.D.C., J.M.A., A.C.R., A.G.B. All authors have read and agreed to the published version of the manuscript. This research was funded by the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq Brazil), grant number GDE 201469/2014-6. Not applicable. The data presented in this study are available on request from the corresponding author. The data are not publicly available due to legal (e.g., privacy) and ethical restrictions.