*Review* **The "ReWaste4.0" Project—A Review**

**Renato Sarc**

Chair of Waste Processing Technology and Waste Management, Montanuniversitaet Leoben, Franz-Josef-Straße 18, 8700 Leoben, Austria; renato.sarc@unileoben.ac.at; Tel.: +43-3842-402-5105

**Abstract:** ReWaste4.0 is an innovative and cooperative K-Project in the period 2017–2021. Through Re-Waste4.0 the transformation of the non-hazardous mixed municipal and commercial waste treatment industry towards a circular economy has started by investigating and applying the new approaches of the Industry 4.0. Vision of the ReWaste4.0 is, among others, the development of treatment plants for non-hazardous waste into a "Smart Waste Factory" in which a digital communication and interconnection between material quality and machine as well as plant performance is reached. After four years of research and development, various results have been gained and the present review article summarizes, links and discuss the outputs (especially from peer-reviewed papers) of seven sub-projects, in total, within the K-project and discusses the main findings and their relevance and importance for further development of the waste treatment sector. Results are allocated into three areas, namely: contaminants in mixed waste and technical possibilities for their reduction as well as removal; secondary raw and energy materials in mixed waste and digitalization in waste characterization and treatment processes for mixed waste. The research conducted in ReWaste4.0 will be continued in ReWaste F for further development towards a particle-, sensor- and data-based circular economy in the period 2021–2025.

**Keywords:** mixed waste; municipal waste; commercial waste; waste treatment; recycling; recovery; contaminants; plastics; digitalisation; smart waste factory
