Surface freshwaters, including rivers, lakes and streams are essential to both ecosystems and communities as they are essential for human health, development and prosperity, and are critical for global nutrient cycling. However, anthropogenic activities and changing climate, have introduced pollutants and contaminants and environmental change that significantly affect fundamental aquatic processes required for healthy and productive surface freshwater systems. Therefore, there is a need for novel advances in effective water quality monitoring, remediation, restoration and treatment solutions that can enhance our understanding and management of surface freshwaters.

This Collection seeks to explore novel advances in:

• Fundamental microbial processes within surface freshwaters.

• Restoration and/or remediation of surface waters including nature-based solutions, decentralized technology solutions and community projects.

• Water quality monitoring technologies, including in situ real time solutions, and low-cost systems appropriate for citizen science programmes.

• Decentralized treatment technologies to improve surface water quality or transform surface waters for alternative uses e.g. drinking water, irrigation, energy and healthcare.

Keywords: Freshwater systems; fundamental microbial processes; nature-based solutions; novel decentralized treatment technologies; novel water quality monitoring technologies and approaches; in-situ real time monitoring; citizen science.

This Collection supports and amplifies research related to SDG 3, SDG 6, SDG 10, and SDG 14.

This Collection aims to provide a comprehensive platform for showcasing interdisciplinary research related to the appraisal and management of water resources.

The energy sector relies heavily on water resources, using substantial amounts to meet our energy needs. The sustainability of water resources should be both quantitative and qualitative, preserving their thermal and chemical characteristics before and after energetic use. One of the key focuses of the collection is the sustainable use of water as a geothermal source of energy for space heating and cooling, electricity production, as well as a underground thermal energy storage systems.

With growing global water scarcity and increasing demand for reliable water sources, many research efforts are addressing water shortages and helping to secure our energy needs through sustainable ideas, which contribute against energy poverty in remote areas. Additionally, the focus includes considering water resources for multiple purposes that complement the use of water for energy purposes, making them versatile and usable in various contexts of energetic use of waters.

Through interdisciplinary research spanning engineering, hydrogeology, hydrology, thermodynamics, materials science, environmental analysis, economic evaluation and social aspects, this Collection seeks to foster effective and scalable solutions. These diverse fields contribute to understanding the complex interactions between water use and energy production, ultimately aiming to supply decision-makers with the data and frameworks necessary for shaping sustainable water use practices that promote sustainable development, resilience, synergy, and beyond.

Expected contributions may cover recent developments aimed at a more conscious and sustainable use and management of water resources for energetic purposes. This includes applications in industry, water consumption, health, space heating and cooling, as well as thermal energy production (e.g., open loop systems) and storage (e.g., ATES, aquifer thermal energy storage).

Keywords: Sustainable water use; Water resources; Energy sector; Geothermal waters; Geothermal energy; Geothermal heating and cooling; Thermal energy storage; Aquifer Thermal Energy Storage; Interactions between water use and energy production; Open loop systems; Groundwater management; Seawater; Environmental protection; Economic evaluation; Water consumption.

This Collection supports and amplifies research related to SDG 6, SDG 7, SDG 8, SDG 9, SDG 11 and SDG 12.