Advances in Water Cycle Management and Circular Economy

Dear Colleagues,

The transition toward a circular economy is reshaping the way societies manage water, shifting from traditional linear models to circular approaches, prioritizing recovery and reuse. Therefore, water management aims to close loops across the entire water cycle, from suitable withdrawals and source protection to advanced treatment and fit-for-purpose reuse.

Technological innovation plays a pivotal role in this transformation. Wastewater treatment plants are evolving into multi-resource recovery facilities capable of valorizing nutrients (such as phosphorus, nitrogen and potassium) and energy production. Advanced and hybrid treatment technologies enable the removal of emerging contaminants like heavy metals, pharmaceuticals and microplastics, while balancing energy consumptions. Moreover, real-time plant monitoring and AI-driven processes can control optimize system performance and emissions.

In parallel, the global regulatory scenario is rapidly evolving. The European Union has introduced ambitious standards for urban wastewater treatment (Directive 2024/3019 updating the older Council Directive 91/271/EEC) and minimum requirement for water reuse (Regulation 2020/741). Worldwide, countries are adopting guidelines to promote safe wastewater treatment and reuse (minimizing pollutant discharges) as well as encouraging investments in circular solutions. These policies are increasingly aligned with broader sustainability objectives, such as reducing carbon footprint, limiting nutrient runoff, preventing biodiversity loss and fostering climate-resilient urban environments.

Together, these technological and regulatory developments signal a profound paradigm shift: water is no longer viewed merely as a consumable resource but as a vital component of a circular and resilient economy.

For this Special Issue, we welcome contributions at the intersection of technology, sustainability, and governance. By bringing together diverse perspectives, the objective is to inspire actionable knowledge and foster global collaboration toward a more resilient, efficient, and circular water future. Topics may include, but are not limited to, the following:

• Alternatives to multi-resource recovery facilities, such as non-conventional approaches, that could enhance resources circularity.
• High-complex holistic management strategies and resource valorization.
• Groundbreaking examples and models of governance, business strategies and policies for circular economy improvements.
• Social acceptance and willingness of population to implement circularity and reuse in everyday habits.
• Resilient and innovative applications that support the circular transition of the water sector.

Dr. Alessandro Moretti
Dr. Matia Mainardis
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 250 words) can be sent to the Editorial Office for assessment.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Water is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.