Water and Circular Cities

A special issue of Water (ISSN 2073-4441). This special issue belongs to the section "Urban Water Management".

Deadline for manuscript submissions: closed (30 June 2021) | Viewed by 80780

Special Issue Editors


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Guest Editor
Faculty of Civil and Geodetic Engineering, University of Ljubljana, Ljubljana, Slovenia
Interests: environmental engineering; water quality management; nature based solutions; ecological/environmental modeling; machine learning

E-Mail Website
Guest Editor
University of Natural Resources and Life Sciences, Vienna (BOKU), Vienna, Austria
Interests: treatment wetlands; nature-based solutions; resource-oriented sanitation; modeling and simulation

Special Issue Information

Dear Colleagues,

This Special Issue follows the idea that water is at the center of the concept of circular cities. Circular water management is closely linked and facilitates sustainable built environment, recovery of resources, and urban farming based on local resources. It also facilitates green spaces, biodiversity, amenity, and sustainable living in the urban setting.

The Special Issue will embrace the knowledge from the COST Action CA17133 Circular City (Implementing nature based solutions (NBS) for creating a resourceful circular city), which incorporates members from all 39 COST countries. The Action represents an interdisciplinary platform for connecting city planners, architects, system designers, economists, engineers, and researchers from social and natural sciences that develop nature-based solutions in the urban landscape that facilitate circular economies based on the 3Rs (reduce, reuse and recover).

The COST Action will contribute a circular view on NBS for sustainable cities in line with the “water at the centre” and from different aspects: urban water management, built environment, resource recovery, urban farming, and transformation tools. Apart from the Action’s papers, the Special Issue invites other papers looking at urban water circles from a wider interdisciplinary perspective.

Dr. Nataša Atanasova
Dr. Günter Langergraber
Guest Editors

Manuscript Submission Information

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Keywords

  • water management
  • circular cities
  • nature-based solutions
  • resource recovery
  • urban farming
  • built environment

Published Papers (14 papers)

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Editorial

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2 pages, 167 KiB  
Editorial
Water and Circular Cities
by Nataša Atanasova and Guenter Langergraber
Water 2021, 13(24), 3585; https://doi.org/10.3390/w13243585 - 14 Dec 2021
Viewed by 1956
Abstract
The Special Issue “Water and Circular Cities” comprises 13 paper and was prepared under the patronage of the COST Action CA17133 Circular City (Implementing nature-based solutions (NBS) for creating a resourceful circular city; https://circular-city [...] Full article
(This article belongs to the Special Issue Water and Circular Cities)

Research

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28 pages, 1120 KiB  
Article
Management of Urban Waters with Nature-Based Solutions in Circular Cities—Exemplified through Seven Urban Circularity Challenges
by Hasan Volkan Oral, Matej Radinja, Anacleto Rizzo, Katharina Kearney, Theis Raaschou Andersen, Pawel Krzeminski, Gianluigi Buttiglieri, Derya Ayral-Cinar, Joaquim Comas, Magdalena Gajewska, Marco Hartl, David C. Finger, Jan K. Kazak, Harri Mattila, Patrícia Vieira, Patrizia Piro, Stefania Anna Palermo, Michele Turco, Behrouz Pirouz, Alexandros Stefanakis, Martin Regelsberger, Nadia Ursino and Pedro N. Carvalhoadd Show full author list remove Hide full author list
Water 2021, 13(23), 3334; https://doi.org/10.3390/w13233334 - 24 Nov 2021
Cited by 39 | Viewed by 8032
Abstract
Nature-Based Solutions (NBS) have been proven to effectively mitigate and solve resource depletion and climate-related challenges in urban areas. The COST (Cooperation in Science and Technology) Action CA17133 entitled “Implementing nature-based solutions (NBS) for building a resourceful circular city” has established seven urban [...] Read more.
Nature-Based Solutions (NBS) have been proven to effectively mitigate and solve resource depletion and climate-related challenges in urban areas. The COST (Cooperation in Science and Technology) Action CA17133 entitled “Implementing nature-based solutions (NBS) for building a resourceful circular city” has established seven urban circularity challenges (UCC) that can be addressed effectively with NBS. This paper presents the outcomes of five elucidation workshops with more than 20 European experts from different backgrounds. These international workshops were used to examine the effectiveness of NBS to address UCC and foster NBS implementation towards circular urban water management. A major outcome was the identification of the two most relevant challenges for water resources in urban areas: ‘Restoring and maintaining the water cycle’ (UCC1) and ‘Water and waste treatment, recovery, and reuse’ (UCC2). s Moreover, significant synergies with ‘Nutrient recovery and reuse’, ‘Material recovery and reuse’, ‘Food and biomass production’, ‘Energy efficiency and recovery’, and ‘Building system recovery’ were identified. Additionally, the paper presents real-life case studies to demonstrate how different NBS and supporting units can contribute to the UCC. Finally, a case-based semi-quantitative assessment of the presented NBS was performed. Most notably, this paper identifies the most typically employed NBS that enable processes for UCC1 and UCC2. While current consensus is well established by experts in individual NBS, we presently highlight the potential to address UCC by combining different NBS and synergize enabling processes. This study presents a new paradigm and aims to enhance awareness on the ability of NBS to solve multiple urban circularity issues. Full article
(This article belongs to the Special Issue Water and Circular Cities)
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22 pages, 1779 KiB  
Article
Nature-Based Solutions for Agriculture in Circular Cities: Challenges, Gaps, and Opportunities
by Alba Canet-Martí, Rocío Pineda-Martos, Ranka Junge, Katrin Bohn, Teresa A. Paço, Cecilia Delgado, Gitana Alenčikienė, Siv Lene Gangenes Skar and Gösta F. M. Baganz
Water 2021, 13(18), 2565; https://doi.org/10.3390/w13182565 - 17 Sep 2021
Cited by 17 | Viewed by 7599
Abstract
Urban agriculture (UA) plays a key role in the circular metabolism of cities, as it can use water resources, nutrients, and other materials recovered from streams that currently leave the city as solid waste or as wastewater to produce new food and biomass. [...] Read more.
Urban agriculture (UA) plays a key role in the circular metabolism of cities, as it can use water resources, nutrients, and other materials recovered from streams that currently leave the city as solid waste or as wastewater to produce new food and biomass. The ecosystem services of urban green spaces and infrastructures and the productivity of specific urban agricultural technologies have been discussed in literature. However, the understanding of input and output (I/O) streams of different nature-based solutions (NBS) is not yet sufficient to identify the challenges and opportunities they offer for strengthening circularity in UA. We propose a series of agriculture NBS, which, implemented in cities, would address circularity challenges in different urban spaces. To identify the challenges, gaps, and opportunities related to the enhancement of resources management of agriculture NBS, we evaluated NBS units, interventions, and supporting units, and analyzed I/O streams as links of urban circularity. A broader understanding of the food-related urban streams is important to recover resources and adapt the distribution system accordingly. As a result, we pinpointed the gaps that hinder the development of UA as a potential opportunity within the framework of the Circular City. Full article
(This article belongs to the Special Issue Water and Circular Cities)
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31 pages, 3108 KiB  
Article
A Framework for Addressing Circularity Challenges in Cities with Nature-Based Solutions
by Guenter Langergraber, Joana A. C. Castellar, Bernhard Pucher, Gösta F. M. Baganz, Dragan Milosevic, Maria-Beatrice Andreucci, Katharina Kearney, Rocío Pineda-Martos and Nataša Atanasova
Water 2021, 13(17), 2355; https://doi.org/10.3390/w13172355 - 27 Aug 2021
Cited by 39 | Viewed by 8555
Abstract
A novel framework is presented that aims to guide practitioners and decision makers toward a better understanding of the role of nature-based solutions (NBS) in the enhancement of resources management in cities, and the mainstreaming of NBS in the urban fabric. Existing frameworks [...] Read more.
A novel framework is presented that aims to guide practitioners and decision makers toward a better understanding of the role of nature-based solutions (NBS) in the enhancement of resources management in cities, and the mainstreaming of NBS in the urban fabric. Existing frameworks describing the use of NBS to address urban challenges do not specifically consider circularity challenges. Thus, the new framework provides the following: (1) a comprehensive set of Urban Circularity Challenges (UCCs); (2) a set of more than fifty NBS units and NBS interventions thoroughly assessed in terms of their potential to address UCCs; and (3) an analysis of input and output resource streams, which are both required for and produced during operation of NBS. The new framework aims to facilitate the coupling of individual NBS units and NBS interventions with NBS that enable circular economy solutions. Full article
(This article belongs to the Special Issue Water and Circular Cities)
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19 pages, 3125 KiB  
Article
Towards a Cross-Sectoral View of Nature-Based Solutions for Enabling Circular Cities
by Guenter Langergraber, Joana A. C. Castellar, Theis Raaschou Andersen, Maria-Beatrice Andreucci, Gösta F. M. Baganz, Gianluigi Buttiglieri, Alba Canet-Martí, Pedro N. Carvalho, David C. Finger, Tjaša Griessler Bulc, Ranka Junge, Boldizsár Megyesi, Dragan Milošević, Hasan Volkan Oral, David Pearlmutter, Rocío Pineda-Martos, Bernhard Pucher, Eric D. van Hullebusch and Nataša Atanasova
Water 2021, 13(17), 2352; https://doi.org/10.3390/w13172352 - 27 Aug 2021
Cited by 15 | Viewed by 5460
Abstract
A framework developed by the COST Action Circular City (an EU-funded network of 500+ scientists from 40+ countries; COST = Cooperation in Science and Technology) for addressing Urban Circularity Challenges (UCCs) with nature-based solutions (NBSs) was analyzed by various urban sectors which refer [...] Read more.
A framework developed by the COST Action Circular City (an EU-funded network of 500+ scientists from 40+ countries; COST = Cooperation in Science and Technology) for addressing Urban Circularity Challenges (UCCs) with nature-based solutions (NBSs) was analyzed by various urban sectors which refer to different fields of activities for circular management of resources in cities (i.e., reducing use of resources and production of waste). The urban sectors comprise the built environment, urban water management, resource recovery, and urban farming. We present main findings from sector analyses, discuss different sector perspectives, and show ways to overcome these differences. The results reveal the potential of NBSs to address multiple sectors, as well as multiple UCCs. While water has been identified as a key element when using NBSs in the urban environment, most NBSs are interconnected and also present secondary benefits for other resources. Using representative examples, we discuss how a holistic and systemic approach could facilitate the circular use of resources in cities. Currently, there is often a disciplinary focus on one resource when applying NBSs. The full potential of NBSs to address multifunctionality is, thus, usually not fully accounted for. On the basis of our results, we conclude that experts from various disciplines can engage in a cross-sectoral exchange and identify the full potential of NBSs to recover resources in circular cities and provide secondary benefits to improve the livelihood for locals. This is an important first step toward the full multifunctionality potential enabling of NBSs. Full article
(This article belongs to the Special Issue Water and Circular Cities)
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14 pages, 2588 KiB  
Article
Practical Performance and User Experience of Novel DUAL-Flush Vacuum Toilets
by Daniel Todt, Iemke Bisschops, Paraschos Chatzopoulos and Miriam H. A. van Eekert
Water 2021, 13(16), 2228; https://doi.org/10.3390/w13162228 - 16 Aug 2021
Cited by 9 | Viewed by 4504
Abstract
Vacuum toilets have gained increasing attention in circular urban development projects, because of their marked water saving qualities compared to conventional flush toilets and the increased resource recovery potential for energy in the form of biogas and phosphorous as, e.g., struvite from the [...] Read more.
Vacuum toilets have gained increasing attention in circular urban development projects, because of their marked water saving qualities compared to conventional flush toilets and the increased resource recovery potential for energy in the form of biogas and phosphorous as, e.g., struvite from the resulting concentrated wastewater. A further reduction of the flushing volume of vacuum toilets would also bring nitrogen recovery options in reach. In the framework of the EU Horizon 2020 project Run4Life, a novel dual-flush vacuum toilet was developed and tested at two sites and combined with an analysis of the flushing patterns and a qualitative user survey. The results show that a 25–50% lower flushing water consumption and accordingly 1.5–2 times higher nutrient concentrations are achievable with this novel type of vacuum toilet. The usage frequency of the dual flush feature was higher in residential homes than in an office building, which also had urinals installed at the men toilets. A notable fraction of toilet visits in which the toilet was flushed twice as well as user feedback on dissatisfactory cleaning effects suggest that the applied reduction in water use is most likely the upper limit of what can be achieved in this type of toilet. Full article
(This article belongs to the Special Issue Water and Circular Cities)
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22 pages, 1054 KiB  
Article
Validating Circular Performance Indicators: The Interface between Circular Economy and Stakeholders
by Chrysanthi-Elisabeth Nika, Alfonso Expósito, Johannes Kisser, Gaetano Bertino, Hasan Volkan Oral, Kaveh Dehghanian, Vasileia Vasilaki, Eleni Iacovidou, Francesco Fatone, Nataša Atanasova and Evina Katsou
Water 2021, 13(16), 2198; https://doi.org/10.3390/w13162198 - 12 Aug 2021
Cited by 12 | Viewed by 4368
Abstract
The development and application of appropriate Circular Economy indicators is an issue that concerns both the scientific and the business community, as well as decision makers. The existing gap between research, policy and practice could be bridged by using a dynamic indicators selection [...] Read more.
The development and application of appropriate Circular Economy indicators is an issue that concerns both the scientific and the business community, as well as decision makers. The existing gap between research, policy and practice could be bridged by using a dynamic indicators selection approach that combines both expert and participatory practices. This study aims to develop such a novel approach for the selection of indicators based on views and needs of practitioners, whilst considering the complex interdependencies of the indicators and determining their importance. Twenty circularity indicators for the Water-Energy-Food-Ecosystems nexus are selected and ranked by different stakeholders. The interrelationships of the indicators are identified using the Interpretive Structural Model, resulting in six levels of importance. Cross-impact matrix multiplication applied to classification (MICMAC) analysis further enabled the classification of the twenty indicators into four categories based on their driving and dependence power. The results indicate that seven indicators—one related to regeneration of natural environment principle, four related to keep resources in use, and two related to design out negative externalities—are the driving indicators to Circular Economy. The approach can be applied to other sets of indicators as well, enabling their prioritization and implementation with other systems. Full article
(This article belongs to the Special Issue Water and Circular Cities)
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34 pages, 3097 KiB  
Article
Closing Water Cycles in the Built Environment through Nature-Based Solutions: The Contribution of Vertical Greening Systems and Green Roofs
by David Pearlmutter, Bernhard Pucher, Cristina S. C. Calheiros, Karin A. Hoffmann, Andreas Aicher, Pedro Pinho, Alessandro Stracqualursi, Alisa Korolova, Alma Pobric, Ana Galvão, Ayça Tokuç, Bilge Bas, Dimitra Theochari, Dragan Milosevic, Emanuela Giancola, Gaetano Bertino, Joana A. C. Castellar, Julia Flaszynska, Makbulenur Onur, Mari Carmen Garcia Mateo, Maria Beatrice Andreucci, Maria Milousi, Mariana Fonseca, Sara Di Lonardo, Veronika Gezik, Ulrike Pitha and Thomas Nehlsadd Show full author list remove Hide full author list
Water 2021, 13(16), 2165; https://doi.org/10.3390/w13162165 - 06 Aug 2021
Cited by 29 | Viewed by 10254
Abstract
Water in the city is typically exploited in a linear process, in which most of it is polluted, treated, and discharged; during this process, valuable nutrients are lost in the treatment process instead of being cycled back and used in urban agriculture or [...] Read more.
Water in the city is typically exploited in a linear process, in which most of it is polluted, treated, and discharged; during this process, valuable nutrients are lost in the treatment process instead of being cycled back and used in urban agriculture or green space. The purpose of this paper is to advance a new paradigm to close water cycles in cities via the implementation of nature-based solutions units (NBS_u), with a particular focus on building greening elements, such as green roofs (GRs) and vertical greening systems (VGS). The hypothesis is that such “circular systems” can provide substantial ecosystem services and minimize environmental degradation. Our method is twofold: we first examine these systems from a life-cycle point of view, assessing not only the inputs of conventional and alternative materials, but the ongoing input of water that is required for irrigation. Secondly, the evapotranspiration performance of VGS in Copenhagen, Berlin, Lisbon, Rome, Istanbul, and Tel Aviv, cities with different climatic, architectural, and sociocultural contexts have been simulated using a verticalized ET0 approach, assessing rainwater runoff and greywater as irrigation resources. The water cycling performance of VGS in the mentioned cities would be sufficient at recycling 44% (Lisbon) to 100% (Berlin, Istanbul) of all accruing rainwater roof–runoff, if water shortages in dry months are bridged by greywater. Then, 27–53% of the greywater accruing in a building could be managed on its greened surface. In conclusion, we address the gaps in the current knowledge and policies identified in the different stages of analyses, such as the lack of comprehensive life cycle assessment studies that quantify the complete “water footprint” of building greening systems. Full article
(This article belongs to the Special Issue Water and Circular Cities)
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17 pages, 2038 KiB  
Article
Application of Multi-Criteria Decision-Making Tools for Assessing Biogas Plants: A Case Study in Reykjavik, Iceland
by Tamara Llano, Elena Dosal, Johannes Lindorfer and David C. Finger
Water 2021, 13(16), 2150; https://doi.org/10.3390/w13162150 - 05 Aug 2021
Cited by 6 | Viewed by 2593
Abstract
The European Union is planning a new program to achieve climate neutrality by 2050. In this context, the Icelandic government plans to ban new registrations of fossil fuel cars after 2030 as one of the strategies to make Iceland a carbon-neutral country by [...] Read more.
The European Union is planning a new program to achieve climate neutrality by 2050. In this context, the Icelandic government plans to ban new registrations of fossil fuel cars after 2030 as one of the strategies to make Iceland a carbon-neutral country by 2040. Upgraded biogas can be directly used in vehicles with CNG engines, reducing CO2 emissions by 80%. In this paper, several alternatives of biogas plants, simulated in previous research, were evaluated by considering techno-economic and environmental criteria through the application of multi-criteria decision-making tools. Twelve alternatives were analyzed using the Definite 3.1 software. A weighted summation algorithm, which transforms all criteria into the same scale by multiplying them by weights and then summing them to obtain the results, was used in the analysis. The multi-criteria analysis of the twelve proposed alternatives included eleven criteria (three technical, five economic, and three environmental) whose weights were changed in a total of eleven scenarios. From a global perspective, when all criteria were considered (9.1% weight) the best alternative with a score of 0.58 was the single-stage biogas plant working with municipal solid waste. Sensitivity and uncertainty analyses also demonstrated that the multi-criteria results obtained were robust and reliable. Full article
(This article belongs to the Special Issue Water and Circular Cities)
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22 pages, 2086 KiB  
Article
Causal Relations of Upscaled Urban Aquaponics and the Food-Water-Energy Nexus—A Berlin Case Study
by Gösta F. M. Baganz, Manfred Schrenk, Oliver Körner, Daniela Baganz, Karel J. Keesman, Simon Goddek, Zorina Siscan, Elias Baganz, Alexandra Doernberg, Hendrik Monsees, Thomas Nehls, Werner Kloas and Frank Lohrberg
Water 2021, 13(15), 2029; https://doi.org/10.3390/w13152029 - 24 Jul 2021
Cited by 9 | Viewed by 6403
Abstract
Aquaponics, the water-reusing production of fish and crops, is taken as an example to investigate the consequences of upscaling a nature-based solution in a circular city. We developed an upscaled-aquaponic scenario for the German metropolis of Berlin, analysed the impacts, and studied the [...] Read more.
Aquaponics, the water-reusing production of fish and crops, is taken as an example to investigate the consequences of upscaling a nature-based solution in a circular city. We developed an upscaled-aquaponic scenario for the German metropolis of Berlin, analysed the impacts, and studied the system dynamics. To meet the annual fish, tomato, and lettuce demand of Berlin’s 3.77 million residents would require approximately 370 aquaponic facilities covering a total area of 224 hectares and the use of different combinations of fish and crops: catfish/tomato (56%), catfish/lettuce (13%), and tilapia/tomato (31%). As a predominant effect, in terms of water, aquaponic production would save about 2.0 million m3 of water compared to the baseline. On the supply-side, we identified significant causal link chains concerning the Food-Water-Energy nexus at the aquaponic facility level as well as causal relations of a production relocation to Berlin. On the demand-side, a ‘freshwater pescatarian diet’ is discussed. The new and comprehensive findings at different system levels require further investigations on this topic. Upscaled aquaponics can produce a relevant contribution to Berlin’s sustainability and to implement it, research is needed to find suitable sites for local aquaponics in Berlin, possibly inside buildings, on urban roofscape, or in peri-urban areas. Full article
(This article belongs to the Special Issue Water and Circular Cities)
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18 pages, 1042 KiB  
Article
Rainwater Use for Vertical Greenery Systems: Development of a Conceptual Model for a Better Understanding of Processes and Influencing Factors
by Flora Prenner, Bernhard Pucher, Irene Zluwa, Ulrike Pitha and Guenter Langergraber
Water 2021, 13(13), 1860; https://doi.org/10.3390/w13131860 - 03 Jul 2021
Cited by 11 | Viewed by 3796
Abstract
Vertical greenery systems (VGS) are promoted as a nature-based solution to mitigate the urban heat island effect. In order to ensure the long-term provision of this function, sufficiently available irrigation water is the key element. Currently, potable water is one of the main [...] Read more.
Vertical greenery systems (VGS) are promoted as a nature-based solution to mitigate the urban heat island effect. In order to ensure the long-term provision of this function, sufficiently available irrigation water is the key element. Currently, potable water is one of the main resources for irrigation of VGS. While rainwater is often mentioned as an alternative, only a few studies investigate the actual application of rainwater for irrigation. In this study a conceptual model is developed to present the processes and influencing factors for a holistic investigation of rainwater use for irrigation. In this model, five sub-modules are identified: the atmospheric, hydraulic, quality, rainwater harvesting and VGS sub-module. The conceptual model depicts which processes and influencing factors are involved in the water demand of VGS. Thus, the conceptual model supports a holistic understanding of the interrelations between the identified sub-modules and their relevance for VGS irrigation with harvested rainwater. The results of this study support the implementation of rainwater harvesting as a sustainable resource for VGS irrigation. Full article
(This article belongs to the Special Issue Water and Circular Cities)
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Review

Jump to: Editorial, Research

52 pages, 1713 KiB  
Review
Nature-Based Units as Building Blocks for Resource Recovery Systems in Cities
by Eric D. van Hullebusch, Aida Bani, Miguel Carvalho, Zeynep Cetecioglu, Bart De Gusseme, Sara Di Lonardo, Maja Djolic, Miriam van Eekert, Tjaša Griessler Bulc, Berat Z. Haznedaroglu, Darja Istenič, Johannes Kisser, Pawel Krzeminski, Sanna Melita, Dolja Pavlova, Elżbieta Płaza, Andreas Schoenborn, Geraldine Thomas, Mentore Vaccari, Maria Wirth, Marco Hartl and Grietje Zeemanadd Show full author list remove Hide full author list
Water 2021, 13(22), 3153; https://doi.org/10.3390/w13223153 - 09 Nov 2021
Cited by 9 | Viewed by 5473
Abstract
Cities are producers of high quantities of secondary liquid and solid streams that are still poorly utilized within urban systems. In order to tackle this issue, there has been an ever-growing push for more efficient resource management and waste prevention in urban areas, [...] Read more.
Cities are producers of high quantities of secondary liquid and solid streams that are still poorly utilized within urban systems. In order to tackle this issue, there has been an ever-growing push for more efficient resource management and waste prevention in urban areas, following the concept of a circular economy. This review paper provides a characterization of urban solid and liquid resource flows (including water, nutrients, metals, potential energy, and organics), which pass through selected nature-based solutions (NBS) and supporting units (SU), expanding on that characterization through the study of existing cases. In particular, this paper presents the currently implemented NBS units for resource recovery, the applicable solid and liquid urban waste streams and the SU dedicated to increasing the quality and minimizing hazards of specific streams at the source level (e.g., concentrated fertilizers, disinfected recovered products). The recovery efficiency of systems, where NBS and SU are combined, operated at a micro- or meso-scale and applied at technology readiness levels higher than 5, is reviewed. The importance of collection and transport infrastructure, treatment and recovery technology, and (urban) agricultural or urban green reuse on the quantity and quality of input and output materials are discussed, also regarding the current main circularity and application challenges. Full article
(This article belongs to the Special Issue Water and Circular Cities)
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34 pages, 1441 KiB  
Review
Impact of Green Roofs and Vertical Greenery Systems on Surface Runoff Quality
by Imane Hachoumi, Bernhard Pucher, Elisabetta De Vito-Francesco, Flora Prenner, Thomas Ertl, Guenter Langergraber, Maria Fürhacker and Roza Allabashi
Water 2021, 13(19), 2609; https://doi.org/10.3390/w13192609 - 22 Sep 2021
Cited by 16 | Viewed by 4998
Abstract
Green roofs (GRs) and vertical greenery systems (VGSs) can contribute certain pollutants to stormwater runoff, affecting the quality of the receiving waters. The objective of this review paper is to discuss the potential impact of these systems on the quality of urban runoff. [...] Read more.
Green roofs (GRs) and vertical greenery systems (VGSs) can contribute certain pollutants to stormwater runoff, affecting the quality of the receiving waters. The objective of this review paper is to discuss the potential impact of these systems on the quality of urban runoff. In the green building systems section, a series of materials used in greenery systems and their specific application are presented and environmentally relevant substances that could be leached out from these materials are identified as potential pollutants. After the identification of environmentally relevant pollutants that have already been measured in urban runoff and originate from these systems, an assessment of their pathways, fate, and impact in the aquatic environment is performed. Since GRs and VGSs are already considered to be solutions for stormwater quantity and quality management in urban areas, recommendations for mitigating their environmental impact through runoff are needed. It can be concluded that special focus should be placed on measures that target the pollution source, such as optimizing GR and VGS construction practices and materials used, as well as establishing appropriate decentralized stormwater treatment measures. Both of these approaches will help to reduce or even entirely avoid the emission of relevant pollutants into the aquatic environment. Full article
(This article belongs to the Special Issue Water and Circular Cities)
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17 pages, 3096 KiB  
Review
Tools for Edible Cities: A Review of Tools for Planning and Assessing Edible Nature-Based Solutions
by Eric Mino, Josep Pueyo-Ros, Mateja Škerjanec, Joana A. C. Castellar, André Viljoen, Darja Istenič, Nataša Atanasova, Katrin Bohn and Joaquim Comas
Water 2021, 13(17), 2366; https://doi.org/10.3390/w13172366 - 28 Aug 2021
Cited by 8 | Viewed by 3338
Abstract
In the last five years, European research and innovation programmes have prioritised the development of online catalogues and tools (handbooks, models, etc.) to facilitate the implementation and monitoring of Nature-Based Solutions (NBS). However, only a few catalogues and toolkits within European programmes are [...] Read more.
In the last five years, European research and innovation programmes have prioritised the development of online catalogues and tools (handbooks, models, etc.) to facilitate the implementation and monitoring of Nature-Based Solutions (NBS). However, only a few catalogues and toolkits within European programmes are directly related to mainstreaming of NBS for food production (i.e., edible NBS). Therefore, the main aim of this paper is to present existing NBS tools through the eyes of productive urban landscapes. We reviewed 32 projects related to NBS and 50 tools were identified and characterised. Then, the six tools already available and provided indicators were further analysed in terms of their format and knowledge domains. Our main conclusion demonstrates that there is a lack of tools capable of supporting users for planning and implementing edible NBS; calculating the food potential of a city and/or of individual edible NBS, including the needed resources for implementation and operation (water, nutrients, energy); and assessing their urban design value, environmental and socio-economic impacts. Moreover, when they do exist, there is a resistance to share the models and equations behind the tools to allow other projects to reuse or validate them, a fact which is contrary to the open science principles upheld by many public research agencies. Full article
(This article belongs to the Special Issue Water and Circular Cities)
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