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Understanding the connection between water supply and energy consumption in a circular economy is crucial for managing the demands of these resources. Sankey diagrams have the potential to enhance the visualisation of resource flows. However, there is a knowledge gap regarding the effective use of Sankey diagrams to capture the water-energy nexus and circularity of water. This study focused on effectively utilizing Sankey diagrams to model the nexus of water and energy flows and to assess the circularity of water. A comprehensive literature review was conducted on major studies on water material flows and modelling. This was supported by a review of approaches for modelling circularity, which have evolved from the material circularity index. The newly developed framework in this paper models water resource flows at all stages of the water supply chain, embedding the nexus as an interaction and considering resource intensity and material circularity index at each node. A city-level case study in South Africa was then used to apply the recommendations, model circularity, and the water-energy nexus using Sankey diagrams. In terms of circularity, the results indicate that water loss in the study area was very high, accounting for up to 40% of the total water supply and the water recycle rate was still very low, ranging from 3% to 7%. In terms of the nexus, the residential sector was found to have the highest energy intensity for water supply, primarily due to energy demand for water heating. Exploring the use of renewable or solar energy for water heating will be of interest and value. The new approach presented in this study allows for the simultaneous consideration of objectives, enabling a more robust analysis of energy-effective water use and water circularity along the water supply chain. [Display omitted] • A new framework for modelling the water energy nexus enriched by circularity options, energy intensity factors and confidence modelling. • Options for embedded circularity through the water supply chain. • The urgent challenge to address massive water loses in water supply systems for water scarce regions. • New Sankey diagrams showcasing how to model nexus and circularity. [ABSTRACT FROM AUTHOR]

• Overview of end-of-life FRP management: waste volume, technologies and legislation. • Literature survey on microwave-assisted FRP recycling: potentials and limitations. • Analysis on the intensification degree provided by microwave vs conventional heating. The growing use of fibre-reinforced polymer (FRP) composites and the increasing global generation of FRP waste implies an urgent need to develop a circular economy strategy to promote the recovery of fibres and the valorisation of resins. This review paper analyses the current scenario of FRP recycling technologies and evaluates the potentials of microwave-assisted heating as a technology to provide an intensification in terms of energy-efficiency, selective heating and processing speed, as well as an electrified thermal treatment for FRP recycling. The paper presents an overview of the estimated FRP production and waste generation per sector in the coming decennia and the current and envisioned international legislation related to the management of end-of-life FRP. The paper also discusses the strong and weak points of the existing FRP recycling technologies, their readiness level and overall environmental impact in terms of equivalent CO 2 emissions. Furthermore, the emerging microwave-assisted FRP recycling technology is evaluated, showcasing the potentials and obstacles for its implementation and the potential end-use and characteristics of the recycled components. A literature survey on the existing prototypes, MW-assisted waste-to-value processes and reported energy demand is conducted. Finally, the required resources and framework for the consolidation of the MW-assisted FRP recycling as an alternative and economically viable technology are assessed. [Display omitted] [ABSTRACT FROM AUTHOR]