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20 pages, 1267 KiB

Open AccessArticle

Work Environment as a Moderator Linking Green Human Resources Management Strategies with Turnover Intention of Millennials: A Study of Malaysian Hotel Industry

by Syed Usman Qadri, Muhammad Amjad Bilal, Mingxing Li, Zhiqiang Ma, Safwan Qadri, Chengang Ye and Fawad Rauf

Sustainability 2022, 14(12), 7401; https://doi.org/10.3390/su14127401 - 16 Jun 2022

Cited by 18 | Viewed by 6156

Abstract

The purpose of this study is to investigate the impact of green human resource management (GHRM) practices (e.g., green pay attention and rewards, green performance management, green involvement, green recruitment and selection, and green training role) on millennial employees’ turnover intention (METI) in [...] Read more.

The purpose of this study is to investigate the impact of green human resource management (GHRM) practices (e.g., green pay attention and rewards, green performance management, green involvement, green recruitment and selection, and green training role) on millennial employees’ turnover intention (METI) in Malaysian three-star, four-star, and five-star hotels with a moderator (work environment) using social exchange theory (SET). The survey used structured questionnaires to collect data from 210 millennial employees using the convenience sampling technique. The research hypotheses were tested using partial least squares structural equation modelling (PLS-SEM). The findings of this study indicate that only green rewards and green involvement have a significant impact on METI. Furthermore, the results indicate that the work environment has no moderating impact on the relationships between green HRM practices and millennial employees’ turnover intention. Finally, the implications, limitations, and future directions for research are also addressed to potential researchers. Full article

(This article belongs to the Special Issue Strategies toward a Green Deal and Circular Economy)

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12 pages, 2237 KiB

Open AccessArticle

Principles of Designing Water Elements in Urban Public Spaces

by Karol Langie, Kinga Rybak-Niedziółka and Věra Hubačíková

Sustainability 2022, 14(11), 6877; https://doi.org/10.3390/su14116877 - 4 Jun 2022

Cited by 4 | Viewed by 7061

Abstract

When designing public spaces in large cities, a number of functional, communication, compositional, infrastructural, environmental and compositional factors should be taken into account, most of which relate to water elements. The appropriate location and form of water elements significantly affect the attractiveness and [...] Read more.

When designing public spaces in large cities, a number of functional, communication, compositional, infrastructural, environmental and compositional factors should be taken into account, most of which relate to water elements. The appropriate location and form of water elements significantly affect the attractiveness and strengthening of the identity of places in cities. Fountains, artificial and natural urbanized watercourses, artistic installations and sculptures, as well as nature-based solutions that utilize water designed in public spaces significantly increase the social and aesthetic value of public spaces. The main aim of the presented research is to present a spectrum of solutions for water elements in public spaces of cities. The summary part describes guidelines and recommendations regarding the principles of designing the locations of fountains, watercourses and artistic objects that utilize water in public spaces in cities. Full article

(This article belongs to the Special Issue Strategies toward a Green Deal and Circular Economy)

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26 pages, 2366 KiB

Open AccessEditor’s ChoiceArticle

Social License for Closure—A Participatory Approach to the Management of the Mine Closure Process

by Aleksandra Kozłowska-Woszczycka and Katarzyna Pactwa

Sustainability 2022, 14(11), 6610; https://doi.org/10.3390/su14116610 - 28 May 2022

Cited by 10 | Viewed by 3312

Abstract

The European Union’s climate policy and the assumptions of the European Green Deal require Poland to take decisive transition efforts. The achievement of climate neutrality is a challenge due to the special role of coal in the Polish economy. Closing mines and abandoning [...] Read more.

The European Union’s climate policy and the assumptions of the European Green Deal require Poland to take decisive transition efforts. The achievement of climate neutrality is a challenge due to the special role of coal in the Polish economy. Closing mines and abandoning coal is the greatest challenge for local communities in mining regions. This article presents the example of Wałbrzych, a Polish post-mining town, which has been experiencing the accumulation of negative consequences of inadequately planned liquidation since the 1990s. The current activities of mining companies in the face of abandoning coal were also analyzed. The gaps identified in the literature indicate the need to define a new method of managing the liquidation processes, based on the consideration of key risks resulting from decommissioning, to minimize the social costs in the first place. In this regard, it is helpful to diagnose the social concerns of the stakeholders. The social aspects of mine closures remain a challenge and finding effective ways to deal with them has become crucial for the industry. This prompted us to propose an approach based on community involvement in the decommissioning processes and the introduction of the social license for closure (SLC). By engaging the community, the SLC gives it a voice, allowing it to accommodate the individual needs of mining regions and ensure a successful and just transition. This article recognizes the key stakeholders and their fears related to the liquidation of mining. The organizational framework for stakeholder approval of the SLC is presented. The analysis was based on the example of Poland, a country facing the challenge of closing hard coal mines. Conclusions formulated on the basis of the case study complement the existing research in the field of social licensing and involving stakeholders in the mine closure planning process in accordance with the idea of corporate social responsibility. Full article

(This article belongs to the Special Issue Strategies toward a Green Deal and Circular Economy)

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13 pages, 1408 KiB

Open AccessArticle

Use of Natural Sorbents in the Processes of Removing Biogenic Compounds from the Aquatic Environment

by Marzena Smol and Dariusz Włóka

Sustainability 2022, 14(11), 6432; https://doi.org/10.3390/su14116432 - 24 May 2022

Cited by 2 | Viewed by 2458

Abstract

This paper presents the results of the evaluation of the possibility of using a selected sorbent of natural origin, mineral (opoka rock), for the removal of biogenic compounds from aqueous solutions. The analyzed opoka rock contains approximately 70% calcium carbonate (CaCO₃) [...] Read more.

This paper presents the results of the evaluation of the possibility of using a selected sorbent of natural origin, mineral (opoka rock), for the removal of biogenic compounds from aqueous solutions. The analyzed opoka rock contains approximately 70% calcium carbonate (CaCO₃) and from 26 to 27% silicon dioxide (SiO₂) and has been classified as heavy opoka rock. The experiment focused on the sorption of organic components, including phosphorus (P), nitrogen (N) and carbon (C). It was carried out for two treatment systems, column tests and batch tests, for three samples of water—water from a water supply system, water from a fish pond and water from a garden pond—located in the region of Silesia (Poland). The results showed that the P removal efficiency was equal to 96.6% for the fine-grained sorbent (grain size <2 mm) and 90.8% for the coarse-grained sorbent (2–4 mm) in the batch tests, while lower effectiveness was observed for the column tests, reaching 67.8% and 54%, respectively. The efficiency of N (NH₄⁺) removal was equal to 84% for both types of sorbents in the batch tests, while it was 47.7% for the fine-grained sorbent and 26.3% for the coarse-grained sorbent in the column tests. The efficiency of the removal of nitrate-nitrogen (NO₃⁻) was higher for the fine-grained sorbent in all analyzed water samples. The use of materials of natural origin in industrial applications is a recommended direction, part of the green transition. The analyzed samples of opoka rock come from deposits, and opoka rock has so far not been analyzed in terms of its possible use in water and sewage treatment technology. Therefore, further research is recommended for this low-cost sorbent, which may be a competitive material for commercial products. Full article

(This article belongs to the Special Issue Strategies toward a Green Deal and Circular Economy)

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16 pages, 6161 KiB

Open AccessArticle

The Impact of Fly Ashes from Thermal Conversion of Sewage Sludge on Properties of Natural Building Materials on the Example of Clay

by Krzysztof Wiśniewski, Gabriela Rutkowska, Katarzyna Jeleniewicz, Norbert Dąbkowski, Jarosław Wójt, Marek Chalecki and Jarosław Siwiński

Sustainability 2022, 14(10), 6213; https://doi.org/10.3390/su14106213 - 20 May 2022

Cited by 5 | Viewed by 1806

Abstract

The reduction of carbon dioxide emissions, introduced by the European Union, opened the possibility of conducting experimental works on a new generation of materials—ecological and environmentally friendly ones. Such materials include those which combine raw natural resources with waste subject to disposal. The [...] Read more.

The reduction of carbon dioxide emissions, introduced by the European Union, opened the possibility of conducting experimental works on a new generation of materials—ecological and environmentally friendly ones. Such materials include those which combine raw natural resources with waste subject to disposal. The objective of the performed investigations was an assessment of the influence of fly ashes on selected parameters of building materials. The paper proposes a method of the enrichment of clay with fly ash, which would lead to the neutralization of heavy metals in the burnt matrix, possible oxidation of organic substances present in the ashes, or the destruction of pathogens, as well as an increase of the resistance of the clay ceramics to low temperatures. Clay samples were prepared with the addition of the fly ash from three sewage treatment plants. The experiments encompassed investigations of physical and chemical properties of the fly ash, as well as bending strength tests of the beam-shaped samples heated at temperatures of 20, 300, 500, and 700 °C. The beam halves, resulting from the destruction of the samples during these tests, served for testing the compressive strength. The collected results allowed a comparison of the properties of the samples. The obtained test results confirm the possibility of manufacturing a product modified with the fly ash from the thermal treatment of sewage sludge. The obtained compressive strength of the samples amounted 0.3–2.6 MPa. Full article

(This article belongs to the Special Issue Strategies toward a Green Deal and Circular Economy)

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13 pages, 2357 KiB

Open AccessArticle

Influence of Ultrasonic Field Parameters on the Biochemical Activity of Leachates from the Composting Process

by Małgorzata Worwąg and Iwona Zawieja

Sustainability 2022, 14(9), 5502; https://doi.org/10.3390/su14095502 - 4 May 2022

Cited by 1 | Viewed by 1514

Abstract

Reuse of leachates by recycling them for composting is part of the circular economy. However, directly returning compost leachates to the mixture might increase the concentration of contaminants in the stabilized mass. The application of the ultrasonic modification of leachate was aimed at [...] Read more.

Reuse of leachates by recycling them for composting is part of the circular economy. However, directly returning compost leachates to the mixture might increase the concentration of contaminants in the stabilized mass. The application of the ultrasonic modification of leachate was aimed at increasing the activity of microorganisms and the availability of nutrients, and reducing the number of pathogenic species. The purpose of the work was to determine the impact of variable ultrasonic (time and amplitude) field parameters on the biochemical properties, and number of selected groups of microorganisms, of leachates from a composting process. The tests used short sonication times of 15, 30, 60, 90, and 120 s and vibration amplitudes of 15.25, 30.5, and 46 µm. The assessment was made on the basis of changes in numbers of microbial communities (mesophilic, thermophilic, Escherichia coli, Salmonella spp. and fungi) and enzymatic activity (dehydrogenases-DHA), as well as respiratory activity (AR). Based on the conducted research, it was found that the leachate sonication time of 60 s and amplitude 30.5 µm were the most effective. The above parameters were considered borderline, above which there were no significant differences in the values of the analyzed indicators. Full article

(This article belongs to the Special Issue Strategies toward a Green Deal and Circular Economy)

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21 pages, 2793 KiB

Open AccessArticle

Situation Analysis and the Potential for Circularity of the Wastewater Sector in Lithuania

by Jolita Kruopienė and Miglė Žiukaitė

Sustainability 2022, 14(9), 5327; https://doi.org/10.3390/su14095327 - 28 Apr 2022

Cited by 5 | Viewed by 2003

Abstract

The concept of circular economy is one of the priority areas for economic development on which the current environmental policy of the European Union is based. Most existing European wastewater treatment plants were built and operated according to the concept of linear economy [...] Read more.

The concept of circular economy is one of the priority areas for economic development on which the current environmental policy of the European Union is based. Most existing European wastewater treatment plants were built and operated according to the concept of linear economy where wastewater and sewage sludge were considered as waste only. In fact, there is a wide range of possibilities to use them as a resource to recover materials and energy. Implementation of the concept of circular economy in a relatively small country requires a great deal of additional research and monitoring to assess the available potential. In this paper, data on municipal wastewater in agglomerations larger than population equivalent of 2000 were analyzed, and the situation is presented through indicators covering prevention, removal, reuse, recycling, and recovery. The novelty of this article is that it evaluates the circularity of Lithuanian wastewater treatment plants and their potential for the future. Thus far, the wastewater sector in the country has been found to largely comply with legal obligations, but very few solutions of circularity were found to be implemented. Full article

(This article belongs to the Special Issue Strategies toward a Green Deal and Circular Economy)

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16 pages, 1261 KiB

Open AccessEditor’s ChoiceArticle

Remote Work Efficiency from the Employers’ Perspective—What’s Next?

by Zenon Pokojski, Agnieszka Kister and Marcin Lipowski

Sustainability 2022, 14(7), 4220; https://doi.org/10.3390/su14074220 - 1 Apr 2022

Cited by 22 | Viewed by 21877

Abstract

Remote work has been of interest to managers since the implementation of new information and communication technologies (ICTs). During the initial period, it was treated as an employee’s privilege or even a luxury and as such it was not a popular practice. The [...] Read more.

Remote work has been of interest to managers since the implementation of new information and communication technologies (ICTs). During the initial period, it was treated as an employee’s privilege or even a luxury and as such it was not a popular practice. The COVID-19 pandemic and the intervening period have changed attitudes toward remote work, as it became a necessity for many organisations. However, in connection with its use, many new, previously unknown problems have arisen, such as: the organisation of remote work, the supervision and monitoring of work performance, and employee support. The present research was conducted using a standardised questionnaire computer-assisted telephone interview (CATI) method in May–June 2021 on a population of 248 enterprises, divided into micro, small, medium-sized and large entities. The research data were collected during the COVID-19 pandemic which, on the one hand, provided an exceptional opportunity to fill in the theoretical gaps that were existing in this field; however, on the other hand, it could be burdened with certain flaws due to the context of the pandemic. An enterprise’s attitude to remote work has a positive influence on the efficiency of the remote work, the control of the remote work and the remote work support, with the strongest impact exerted on the last of the factors mentioned. A better attitude to remote work influences, to the largest degree, an enterprise’s support for performing work from remote locations outside of corporate offices. Among the enterprises that were surveyed, the following were most frequently indicated as elements of such support: additional office equipment provided to an employee, remote work training, and the installation of additional computer programs. Financial support was declared by about 11% of the enterprises and it usually took the form of a remote work allowance or funds to cover the costs of purchasing equipment or paying for the Internet. Full article

(This article belongs to the Special Issue Strategies toward a Green Deal and Circular Economy)

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19 pages, 1029 KiB

Open AccessArticle

Structural Equation Model of Factors Influencing the Selection of Industrial Waste Disposal Service in Cement Kilns

by Ukrit Suksanguan, Somsak Siwadamrongpong, Thanapong Champahom, Sajjakaj Jomnonkwao, Tassana Boonyoo and Vatanavongs Ratanavaraha

Sustainability 2022, 14(7), 4109; https://doi.org/10.3390/su14074109 - 30 Mar 2022

Cited by 3 | Viewed by 2643

Abstract

Industrial waste disposal in a cement kiln is an operation that includes waste disposal as well as the conversion of waste into renewable energy, which is a cement industry in many countries. This research studied business factors related to the intention to use [...] Read more.

Industrial waste disposal in a cement kiln is an operation that includes waste disposal as well as the conversion of waste into renewable energy, which is a cement industry in many countries. This research studied business factors related to the intention to use co-processing industrial waste disposal service in cement kilns by surveying the data with questionnaires from 1251 customers nationwide. The objectives of this research were to study the relationship of business factors by using structural equation modeling to analyze factors influencing the selection of industrial waste disposal service in cement kilns. The study results found that customer attitude towards the following factors, including perceived ease of use, perceived usefulness, disposal price, service provider location, promotion, people, and a service provider’s infrastructure, influenced intention to use the service. The variables that customers gave importance to were the industrial waste disposal with zero wastes to landfill and the use of industrial waste relevant to the circular economy by using the industrial waste, which has a quality of renewable fuel in cement kiln as the renewable fuel of the cement furnace. According to the research results, service providers in cement kilns can potentially plan service strategies to achieve sustainability for further business operations in a highly competitive market. Full article

(This article belongs to the Special Issue Strategies toward a Green Deal and Circular Economy)

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20 pages, 3515 KiB

Open AccessArticle

Towards a Model for Analyzing the Circular Economy in Ecuadorian Companies: A Conceptual Framework

by Gabriela Sucozhañay, Iván Vidal and Paúl Vanegas

Sustainability 2022, 14(7), 4016; https://doi.org/10.3390/su14074016 - 29 Mar 2022

Cited by 7 | Viewed by 3422

Abstract

A successful implementation of a CE requires an appropriate comprehension of its conceptual framework and the identification of the elements that composed it. However, there is still no consensus on a unique CE definition, which makes it difficult for companies to adopt circular [...] Read more.

A successful implementation of a CE requires an appropriate comprehension of its conceptual framework and the identification of the elements that composed it. However, there is still no consensus on a unique CE definition, which makes it difficult for companies to adopt circular practices in their business models. In this context, this study proposes a CE framework based on four fundamental elements: principles, drivers, stakeholders and strategies, which was complemented by circular-organization-oriented metrics. Then, local case studies were used to assess the implementation of CE strategies in Ecuadorian companies. Among the identified elements, it was found that there are general action lines that facilitate the understanding of the CE. On the other hand, the majority of elements and metrics are oriented toward the production and end-of-life stages, while extraction, design, use, marketing and distribution are less considered. Furthermore, although environmental, economic and social aspects are considered, the latter are mostly limited to employment generation. Finally, for the local case studies it was observed that the current adoption of circular practices in companies derives from the incorporation of the sustainability approach instead of a structured and systematic implementation of CE strategies. Full article

(This article belongs to the Special Issue Strategies toward a Green Deal and Circular Economy)

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22 pages, 4878 KiB

Open AccessArticle

Ecosystem of Environmentally Sustainable Municipal Infrastructure in Ukraine

by Viktor Koval, Piotr Olczak, Nataliia Vdovenko, Olena Boiko, Dominika Matuszewska and Inesa Mikhno

Sustainability 2021, 13(18), 10223; https://doi.org/10.3390/su131810223 - 13 Sep 2021

Cited by 28 | Viewed by 3806

Abstract

For the Ukrainian population, there are factors surrounding the choices and preferences one must consider when changing permanent residence. Smart residential areas should be built according to Ukrainian legislation and global innovations, which would reduce administrative dislocations, the load on megalopolises, and negative [...] Read more.

For the Ukrainian population, there are factors surrounding the choices and preferences one must consider when changing permanent residence. Smart residential areas should be built according to Ukrainian legislation and global innovations, which would reduce administrative dislocations, the load on megalopolises, and negative anthropogenic impacts, and should be based on the increase in energy efficiency and reducing waste. We analyzed the core principles of designing smart residential areas and concluded that constructing cutting-edge residential areas should involve private investments in order to avoid shadow schemes and irrational use of funds (in the Ukraine, the share of the shadow market is more than 50%). Research shows that, as humans inhabit a three-dimensional space, it is possible to predict migration and other permanent residence/behavioral responses, the analysis of which allows controlling migration flows and improves the conditions of Ukraine’s small residential areas based on decarbonization. We conclude that energy saving systems can reduce consumption in a city by 60% and improve Ukraine’s ecosystem. Research also shows that reducing “dislocation”, in terms of population density, by creating open, innovative, eco-friendly environments based on green economy principles, can provide innovative development maps and economic, social, and cultural population growth, decreasing the load on big cities/regional economies, and encourage the restoration of sales markets and production after the COVID-19 pandemic. We developed a model to assess the innovativeness of residential areas, apply alternative methods of energy generation, and analyze the impact of the energy production and consumption market in Europe (with recommendations for the Ukraine). This article estimates energy intensity indicators of the gross domestic product in the Ukraine and in Europe, offering methods to decrease energy dependence and increase energy efficiency in the Ukraine, by adopting alternative energy sources (e.g., biohydrogen out of residues, air, and solar energy), and enhancing environmental legislation. Full article

(This article belongs to the Special Issue Strategies toward a Green Deal and Circular Economy)

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20 pages, 20760 KiB

Open AccessArticle

Monitoring and Assessment of Groundwater Quality at Landfill Sites: Selected Case Studies of Poland and the Czech Republic

by Anna Podlasek, Aleksandra Jakimiuk, Magdalena Daria Vaverková and Eugeniusz Koda

Sustainability 2021, 13(14), 7769; https://doi.org/10.3390/su13147769 - 12 Jul 2021

Cited by 26 | Viewed by 4355

Abstract

In order to protect the components of natural environment, each landfill must be properly secured and the monitoring program should be adopted. This study aims to present a comparative analysis of groundwater quality at selected landfill sites in Poland and the Czech Republic, [...] Read more.

In order to protect the components of natural environment, each landfill must be properly secured and the monitoring program should be adopted. This study aims to present a comparative analysis of groundwater quality at selected landfill sites in Poland and the Czech Republic, with a special attention given to the levels and temporal changes of heavy metals (HMs) concentrations measured in collected groundwater samples. A secondary objective was to detect possible leakages of pollutants from the landfill body, into the groundwater, and further into the environment. The assessment of groundwater quality was based on a comparison of HMs concentrations with standards provided by the European environmental laws. On the basis of the long-term monitoring period, it was revealed, for the Polish landfill site, that the groundwater quality is improving over time, especially due to remedial works applied. For the Czech landfill, it was observed that the quality of groundwater is not negatively affected by the operation of the landfill, but in the immediate vicinity of the landfill, the groundwater quality is significantly affected by the agricultural use of neighbouring lands, as well as by the storage of construction and demolition wastes. The results showed that the leachate did not leak outside the landfills, especially due to minimal concentrations of HMs, measured in groundwater samples, taken from the piezometers located in the outflow direction from the landfills. Full article

(This article belongs to the Special Issue Strategies toward a Green Deal and Circular Economy)

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16 pages, 6109 KiB

Open AccessArticle

Effect of Acetic Acid on Compressive Strength and Geometric Texture of the Surface of C20/25 Class Concrete

by Joanna Witkowska-Dobrev, Olga Szlachetka, Marek Dohojda and Krzysztof Wiśniewski

Sustainability 2021, 13(9), 5136; https://doi.org/10.3390/su13095136 - 4 May 2021

Cited by 16 | Viewed by 3765

Abstract

Concrete is a highly alkaline material; therefore, the presence of organic acids (acetic, butyric, lactic) from agricultural sewage constitutes a threat to the concrete and the environment. The investigations were aimed at simulating the influence of highly concentrated organic acids on concrete elements [...] Read more.

Concrete is a highly alkaline material; therefore, the presence of organic acids (acetic, butyric, lactic) from agricultural sewage constitutes a threat to the concrete and the environment. The investigations were aimed at simulating the influence of highly concentrated organic acids on concrete elements of livestock buildings. Cubic samples 100 × 100 × 100 mm of the ordinary concrete were immersed in 10% acetic acid for 270 days. Then, the compressive strength and mass decrement of the samples were determined as well as using SEM images and a 3D-profilograph to profile the surface roughness and depth of changes evoked in the structure of the samples by penetrating acid. The results were compared with those for a control sample (not subjected to the effects of aggressive agents) as well as for samples placed in a neutral and alkaline environment. The compressive strength of the samples stored in the acidic environment was 22.23% lower than that of the control sample, whereas the compressive strength of those samples stored in an alkaline environment were 44.27% higher. Conclusions from these investigations can be of innovative importance in the preparation of environmental impact reports, which are necessary for obtaining permission for the construction and use of livestock buildings, and afterward in the reduction of the impact of these buildings on the environment and surface and underground water resources. Full article

(This article belongs to the Special Issue Strategies toward a Green Deal and Circular Economy)

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20 pages, 3047 KiB

Open AccessArticle

Application of Shrimp Waste for the Synthesis of Polyurethane–Chitosan Materials with Potential Use in Sorption of Oil Micro-Spills in Water Treatment

by Agnieszka Piotrowska-Kirschling, Katarzyna Szelągowska-Rudzka, Jakub Karczewski and Joanna Brzeska

Sustainability 2021, 13(9), 5098; https://doi.org/10.3390/su13095098 - 1 May 2021

Cited by 9 | Viewed by 3593

Abstract

Shrimp waste is a common waste in seafood processing. It is used as part of the fish meal which is added to feed. Bearing in mind the Green Deal and sustainability development, it was proposed to use northern prawn shells to obtain chitosan [...] Read more.

Shrimp waste is a common waste in seafood processing. It is used as part of the fish meal which is added to feed. Bearing in mind the Green Deal and sustainability development, it was proposed to use northern prawn shells to obtain chitosan (Ch), which could then be used for polyurethane (PUR) modification. In ports, oil micro-spills often flow into the waters of gulfs and, consequently, into the sea. Systematic chemical and petroleum water pollution may pose a threat to flora and fauna. In this study, chitosan, which was obtained from shrimp shells, was used to synthesize polyurethane–chitosan foams (PUR+Ch) with different chitosan concentrations. Selected physico-chemical and sorption properties in relation to oil and water of these materials were determined. It was found that the amount of Ch added to the foam affected its morphology, hardness, density, and thermal and sorption properties. PUR foam with a 1.5% weight of Ch was characterized as having the highest water and oil sorption. The advantages of the tested material as an innovative product with potentially significant proecological values were estimated using strengths–weaknesses–opportunities–threats (SWOT) analysis. The conducted preliminary research made it possible to demonstrate the use of these materials in the processes of water treatment with the mentioned micropollutants. Full article

(This article belongs to the Special Issue Strategies toward a Green Deal and Circular Economy)

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17 pages, 2334 KiB

Open AccessArticle

Implementing Regional Circular Economy Policies: A Proposed Living Constellation of Stakeholders

by Sanja Arsova, Andrea Genovese, Panayiotis H. Ketikidis, Josep Pinyol Alberich and Adrian Solomon

Sustainability 2021, 13(9), 4916; https://doi.org/10.3390/su13094916 - 27 Apr 2021

Cited by 27 | Viewed by 4874

Abstract

The transition towards the circular economy (CE) entails transformative and system-wide changes, implying involvement, alignment, and cooperation between all stakeholders at all levels. However, debate continues around how best to achieve this. Additionally, little attention has been paid to developing models for identifying [...] Read more.

The transition towards the circular economy (CE) entails transformative and system-wide changes, implying involvement, alignment, and cooperation between all stakeholders at all levels. However, debate continues around how best to achieve this. Additionally, little attention has been paid to developing models for identifying and mobilising all relevant stakeholders to implement CE policies at the regional level. This study sought to remedy these issues by analysing the relevant academic literature and policy documents and making the first attempt to adjust existing models—not only for the purpose of stakeholder mapping, but also for the proposition of a living constellation of stakeholders who should be considered when designing the transition towards a CE in a regional scenario. The CE-centric quintuple-helix model developed and proposed here promotes the emergence and deployment of trilateral networks, hybrid organisations, and development/co-operation platforms. This model adopts a balanced, participatory approach that requires a new constellation of stakeholders. Its foundations are built on the traditional industry–government–academia nexus and enlarged by the inclusion of the civil society sphere and the environmental subsystem. The environment is represented as the nucleus of the model, inspiring and triggering actions by the remaining four subsystems. The model is then implemented into two European regions with CE initiatives (Spain and Greece) to demonstrate its practical application. Full article

(This article belongs to the Special Issue Strategies toward a Green Deal and Circular Economy)

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13 pages, 6234 KiB

Open AccessArticle

Removal of Selected Dyes on Activated Carbons

by Ewa Okoniewska

Sustainability 2021, 13(8), 4300; https://doi.org/10.3390/su13084300 - 13 Apr 2021

Cited by 19 | Viewed by 2848

Abstract

Dyes are widely used in various industries such as those involving paper, food, plastics, and fibers. The produced wastewater has a specific character. Organic substances found in wastewater and when introduced into natural water bodies have a toxic effect on living organisms, causing [...] Read more.

Dyes are widely used in various industries such as those involving paper, food, plastics, and fibers. The produced wastewater has a specific character. Organic substances found in wastewater and when introduced into natural water bodies have a toxic effect on living organisms, causing increased chemical and biological oxygen demand. Some dyes, even in very low concentrations, cause intense colouring. To remove dyes from wastewater, methods such as flotation, oxidation, ozonation, filtration or coagulation with metal compounds are used. Unfortunately, when these methods are used, very large amounts of sludge are produced, which is another problem for the environment. Therefore, one of the methods that can effectively remove dyes from wastewater without creating large amounts of waste is activated carbon adsorption. Adsorption methods in the treatment of wastewater from the dye industry are of particular importance due to their high efficiency, ability to operate over a relatively wide range of concentrations, and availability. The most common adsorbent is activated carbon, which has a high adsorption capacity against many organic compounds. The aim of this study was to determine the effect of filtration rate and type of activated carbon on the removal efficiency of selected cationic (anilan yellow) and anionic (tartrazine) dyes from aqueous solutions. Full article

(This article belongs to the Special Issue Strategies toward a Green Deal and Circular Economy)

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14 pages, 3488 KiB

Open AccessArticle

Fly Ash from Thermal Conversion of Sludge as a Cement Substitute in Concrete Manufacturing

by Gabriela Rutkowska, Marek Chalecki and Mariusz Żółtowski

Sustainability 2021, 13(8), 4182; https://doi.org/10.3390/su13084182 - 9 Apr 2021

Cited by 14 | Viewed by 3261

Abstract

Striving for reduction of production costs and constraints on natural resources cause the use of waste materials as substitutes of traditional raw materials to become increasingly important. Dynamic development of sewerage systems and sewage treatment plants observed over the recent years leads to [...] Read more.

Striving for reduction of production costs and constraints on natural resources cause the use of waste materials as substitutes of traditional raw materials to become increasingly important. Dynamic development of sewerage systems and sewage treatment plants observed over the recent years leads to increase of mass of the produced sewage sludge. According to the Waste Law, the municipal sewage sludge can be used if it is properly stabilized, e.g., through thermal processing. This process results in significant quantities of fly ash which must be properly utilized. The paper presents results of investigations of influence of partial replacement of cement by the fly ash from sewage sludge on concrete parameters. It was designed as a C20/25 class concrete mix, based on the Portland cement CEM I 42.5R with various ash content. Physical and chemical properties of the ash as well as frost resistance and the compressive strength of the concrete after 28, 56 and 365 days of curing were investigated. The obtained results of investigations confirm the possibility of application of fly ash wastes as a cement substitute in the concrete manufacturing. If a predefined quantity of cement is replaced by the fly ash, then one can obtain cement composite with good strength parameters. Full article

(This article belongs to the Special Issue Strategies toward a Green Deal and Circular Economy)

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18 pages, 5574 KiB

Open AccessArticle

Remediating Agricultural Legacy Nutrient Loads in the Baltic Sea Region

by Julia Tanzer, Ralf Hermann and Ludwig Hermann

Sustainability 2021, 13(7), 3872; https://doi.org/10.3390/su13073872 - 31 Mar 2021

Cited by 6 | Viewed by 2918

Abstract

The Baltic Sea is considered the marine water body most severely affected by eutrophication within Europe. Due to its limited water exchange nutrients have a particularly long residence time in the sea. While several studies have analysed the costs of reducing current nutrient [...] Read more.

The Baltic Sea is considered the marine water body most severely affected by eutrophication within Europe. Due to its limited water exchange nutrients have a particularly long residence time in the sea. While several studies have analysed the costs of reducing current nutrient emissions, the costs for remediating legacy nutrient loads of past emissions remain unknown. Although the Baltic Sea is a comparatively well-monitored region, current data and knowledge is insufficient to provide a sound quantification of legacy nutrient loads and much less their abatement costs. A first rough estimation of agricultural legacy nutrient loads yields an accumulation of 0.5–4.0 Mt N and 0.3–1.2 Mt P in the Baltic Sea and 0.4–0.5 Mt P in agricultural soils within the catchment. The costs for removing or immobilising this amount of nutrients via deep water oxygenation, mussel farming and soil gypsum amendment are in the range of few tens to over 100 billion €. These preliminary results are meant as a basis for future studies and show that while requiring serious commitment to funding and implementation, remediating agricultural legacy loads is not infeasible and may even provide economic benefits to local communities in the long run. Full article

(This article belongs to the Special Issue Strategies toward a Green Deal and Circular Economy)

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17 pages, 7100 KiB

Open AccessArticle

Polish Rural Designing System Used for the Implementation of the Ideas of Green Deal and Sustainability—Comparison of Landscape and Agricultural Areas Planning, on the Example of Strzelce Wielkie and Kamionka Wielka

by Przemysław Baster and Urszula Litwin

Sustainability 2021, 13(2), 886; https://doi.org/10.3390/su13020886 - 17 Jan 2021

Cited by 4 | Viewed by 2735

Abstract

Issues related to the system of protection and planning of rural landscape undoubtedly differ from the topics concerning the transformation of agricultural areas and their proper management. These are separate specialties, studied by researchers representing different disciplines, although they often relate to the [...] Read more.

Issues related to the system of protection and planning of rural landscape undoubtedly differ from the topics concerning the transformation of agricultural areas and their proper management. These are separate specialties, studied by researchers representing different disciplines, although they often relate to the same village and they are aimed to implement the ideas of the Green Deal and sustainability. The experience from independent research projects in Kamionka Wielka (agricultural areas), and Strzelce Wielkie (landscape of rural and green areas) confirm the variety of individual issues and topics discussed. Nevertheless, the comparison of these projects also points to similar methods of analysis and planning applying a Polish four-stage landscape designing system: ‘resources—valorization—guidelines—design’. The research results indicate that this system, almost identical to the European ones, can be also useful for planning agricultural areas. In practice, this will allow local authorities to realize the idea of the Green Deal—draw up a more perfect development project for the whole village and simultaneously standardize project documentation. Designers and scientists will achieve better cooperation and fitting spatial planning solutions; this way, interdisciplinary activities and final design will implement the ideas of sustainability and Green Deal. Full article

(This article belongs to the Special Issue Strategies toward a Green Deal and Circular Economy)

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18 pages, 317 KiB

Open AccessArticle

Joint Pricing and Ordering Problem with Charitable Donations

by Nur Ayvaz Çavdaroğlu

Sustainability 2020, 12(17), 6950; https://doi.org/10.3390/su12176950 - 26 Aug 2020

Viewed by 2184

Abstract

Finding the correct pricing strategy for a product with multiple versions is an issue for retailers from various industries. In this paper, joint pricing and ordering problem is considered for a product that has two versions at each selling period. Two models, namely [...] Read more.

Finding the correct pricing strategy for a product with multiple versions is an issue for retailers from various industries. In this paper, joint pricing and ordering problem is considered for a product that has two versions at each selling period. Two models, namely with or without the donation option, are analyzed and optimality conditions and monotonicity properties of the decision variables are characterized. When demands of products depend on prices of both versions, donating part of old product inventory would be more profitable for the retailer. Moreover, the donation model would result in less wasted inventory, contributing to sustainability and goals of green economy. Analytical results are supported with numerical analysis of a realistic case. Full article

(This article belongs to the Special Issue Strategies toward a Green Deal and Circular Economy)

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31 pages, 2572 KiB

Open AccessReview

Recent Advances in Carbon Dioxide Conversion: A Circular Bioeconomy Perspective

by TsingHai Wang, Cheng-Di Dong, Jui-Yen Lin, Chiu-Wen Chen, Jo-Shu Chang, Hyunook Kim, Chin-Pao Huang and Chang-Mao Hung

Sustainability 2021, 13(12), 6962; https://doi.org/10.3390/su13126962 - 21 Jun 2021

Cited by 4 | Viewed by 3827

Abstract

Managing the concentration of atmospheric CO₂ requires a multifaceted engineering strategy, which remains a highly challenging task. Reducing atmospheric CO₂ (CO2R) by converting it to value-added chemicals in a carbon neutral footprint manner must be the ultimate goal. The latest progress [...] Read more.

Managing the concentration of atmospheric CO₂ requires a multifaceted engineering strategy, which remains a highly challenging task. Reducing atmospheric CO₂ (CO2R) by converting it to value-added chemicals in a carbon neutral footprint manner must be the ultimate goal. The latest progress in CO2R through either abiotic (artificial catalysts) or biotic (natural enzymes) processes is reviewed herein. Abiotic CO2R can be conducted in the aqueous phase that usually leads to the formation of a mixture of CO, formic acid, and hydrogen. By contrast, a wide spectrum of hydrocarbon species is often observed by abiotic CO2R in the gaseous phase. On the other hand, biotic CO2R is often conducted in the aqueous phase and a wide spectrum of value-added chemicals are obtained. Key to the success of the abiotic process is understanding the surface chemistry of catalysts, which significantly governs the reactivity and selectivity of CO2R. However, in biotic CO2R, operation conditions and reactor design are crucial to reaching a neutral carbon footprint. Future research needs to look toward neutral or even negative carbon footprint CO2R processes. Having a deep insight into the scientific and technological aspect of both abiotic and biotic CO2R would advance in designing efficient catalysts and microalgae farming systems. Integrating the abiotic and biotic CO2R such as microbial fuel cells further diversifies the spectrum of CO2R. Full article

(This article belongs to the Special Issue Strategies toward a Green Deal and Circular Economy)

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