Book excerpt: Wastes: Solutions, Treatments and Opportunities III contains selected papers presented at the 5th edition of the International Conference Wastes: Solutions, Treatments and Opportunities, that took place on 3-6 September 2019, in Costa da Caparica, Portugal. The Wastes conference, which takes place biennially, is a prime forum for sharing innovation, technological development and sustainable solutions for the waste management and recycling sectors around the world, counting with the participation of experts from academia and industry. The papers included in this book cover a wide range of topics, including: Wastes as construction materials; Wastes as fuels; Waste treatment technologies; MSW management; Recycling of wastes and materials recovery; Environmental, economic and social aspects in waste management; Life cycle assessment; Circular economy and wastes refineries; Logistics, policies, regulatory constraints and markets in waste management.