Circular Economy最新文献

{"title":"Formulating efficient P-rich biobased starter fertilizers: Effects of acidification and pelletizing on fertilizer properties","authors":"Pietro Sica ,&nbsp;Dorette Müller-Stöver ,&nbsp;Jakob Magid","doi":"10.1016/j.cec.2024.100111","DOIUrl":"10.1016/j.cec.2024.100111","url":null,"abstract":"<div><div>Animal-derived biowastes can be alternatives to mineral phosphorus fertilizers. However, they typically have lower efficiency and higher transport costs because of their low bulk density. Pelleting can reduce their volume and facilitate their use as placement fertilizers but may also decrease phosphorus availability. This study examined how acidification and pelletizing affect phosphorus availability in biowastes. Digestate solid fraction and meat and bone meal were treated in four ways: (1) untreated (U), (2) acidified (A), (3) untreated pelletized (UP), and (4) acidified pelletized (AP). These treatments were tested in soil incubation and pea growth experiments, with fertilizers placed 5 cm beneath the seeds to evaluate their effectiveness as placement fertilizers. Acidification significantly enhanced the phosphorus solubility of DSF and MBM by approximately 5 and 7 times respectively, while pelletizing acidified materials reduced it. In the incubation experiment, acidified materials in the powdery form showed the highest soil water-extractable phosphorus, with no significant differences among U, UP, and AP ways. In the rhizobox experiment, pelletizing untreated digestate significantly reduced plant dry matter compared to the untreated fibrous form (from 2.0 g to 1.35 g). Acidified and acidified pelletized digestate treatments resulted in the highest shoot dry matter (2.8 g and 2.95 g, respectively), surpassing even triple the amount of superphosphate (2.53 g). For meat and bone meal, the acidified powder led to the highest plant growth (2.0 g), while untreated powder resulted in the lowest amount of plant growth (0.4 g), which was lower than that of the negative control (0.6 g). No significant differences were noted between untreated and acidified pellets. These findings indicate that acidification enhances phosphorus availability in biowastes, while pelletizing reduces it. The acidified pelletized digestate solid fraction has lower volume and higher P use efficiency than its untreated material, showing higher plant growth when compared to mineral P fertilizer.</div></div>","PeriodicalId":100245,"journal":{"name":"Circular Economy","volume":"3 4","pages":"Article 100111"},"PeriodicalIF":0.0,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142530568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isothermal pyrolysis of discarded bakelite: Kinetics analysis and batch pyrolysis studies","authors":"Pabitra Mohan Mahapatra ,&nbsp;Dipransu Pradhan ,&nbsp;Sachin Kumar ,&nbsp;Achyut Kumar Panda","doi":"10.1016/j.cec.2024.100102","DOIUrl":"10.1016/j.cec.2024.100102","url":null,"abstract":"<div><p>Plastic is widely used, leading to an increase in plastic waste in the environment and resulting in pollution. Plastic waste can currently be managed differently and reduced by converting it into useful products via different methods. The extensive use of thermosetting polymers such as bakelite, which are nonrecyclable, has led to an increase in bakelite scrap and pollution. Therefore, minimizing pollution due to such waste requires sustainable, modern, eco-friendly, and economical recycling technology and the upgrading of existing recycling technology. This work reports the recycling of discarded bakelite through pyrolysis and a kinetic study of the isothermal pyrolysis of bakelite via model fitting methods as well as product analyses. Therefore, isothermal degradation experiments for discarded bakelite were carried out at different temperatures (300, 350, 400, 450, and 500 °C) for 2 h. The isothermal degradation of bakelite follows the D₁-diffusion model fitting method, with an activation energy (<em>E</em>_a) of 17.178 kJ/mol and an Arrhenius constant (<em>A</em>) of 0.095 min⁻¹. The kinetic information provided throughout the research will aid in the development of an appropriate reactor for the valorization of discarded bakelite. Batch pyrolysis of bakelite gives the highest yield of 39.12% pyrolytic waxy oil at 450 °C. The presence of components such as alkanes, cycloalkenes, alkenes, alcohols, ethers, and aromatic compounds in the pyrolytic waxy oil and residue was confirmed by FTIR and GC‒MS analysis.</p></div>","PeriodicalId":100245,"journal":{"name":"Circular Economy","volume":"3 3","pages":"Article 100102"},"PeriodicalIF":0.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S277316772400030X/pdfft?md5=d009b6c8867e002fea12c2bcaff8942c&pid=1-s2.0-S277316772400030X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142172096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterizing the packaging waste generation patterns and carbon emissions of university delivery service","authors":"Huabo Duan ,&nbsp;Guanghan Song ,&nbsp;Qiuxia Zou ,&nbsp;Ruichang Mao ,&nbsp;Xiao Liu","doi":"10.1016/j.cec.2024.100103","DOIUrl":"10.1016/j.cec.2024.100103","url":null,"abstract":"<div><p>As the main consumer group for online shopping and ordering fast food, young people—particularly university students—have contributed to a substantial amount of packaging waste. In the present study, the material flow method was employed to quantify the generation and end-of-life flows of packaging waste from both the express delivery and food delivery sectors at universities in China. Moreover, this study takes reusable packaging materials for food delivery services as a case study to evaluate their environmental benefits through a simplified life cycle assessment approach. The results show that approximately 1.7 (±0.3) million metric tons and 123 (±1.0) kilo metric tons of packaging waste were generated from express delivery and food delivery services, respectively, for university students in 2021. Although reusable food packaging is more complex and costly than regular disposable food packaging is, our modeling results show that reusable food packaging has significant emission reduction benefits under the current practice of 63 cycles per year of actual operation at a specific university. The reusable packaging mode in universities is feasible from an environmental perspective; however, it faces significant challenges due to a few concerns among stakeholders, such as high costs and inadequate recycling supply systems.</p></div>","PeriodicalId":100245,"journal":{"name":"Circular Economy","volume":"3 3","pages":"Article 100103"},"PeriodicalIF":0.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2773167724000311/pdfft?md5=3f09542abe9827a809c321dd12300f3b&pid=1-s2.0-S2773167724000311-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142172097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"3D printing of alkali-activated geopolymers for sustainable and circular economy advancements","authors":"Arslan Yousaf,&nbsp;Ans Al Rashid,&nbsp;Muammer Koç","doi":"10.1016/j.cec.2024.100101","DOIUrl":"10.1016/j.cec.2024.100101","url":null,"abstract":"<div><p>The urgent global challenges of climate change and resource overconsumption highlight the need for sustainable innovations in the construction industry. Ordinary Portland cement, a vital construction material, significantly contributes to carbon emissions. Alkali-activated materials have emerged as promising alternatives. Three-dimensional printing (3DP) has gained attention in construction, because it offers efficiency and sustainability benefits. This study addresses the integration of alkali-activated materials and 3DP, focusing on circular economy implications. This study examines 1200 research articles from the Scopus database and comprehensively reviews 47 articles on 3DP of geopolymer structures. This study identifies critical research gaps, including a lack of focus on 3DP for alkali-activated materials, circular economy models, optimal mixtures, anisotropy mitigation, reinforcement strategies, and scalability. These insights highlight the transformative potential of 3DP with alkali-activated materials in sustainable construction, fostering a circular economy.</p></div>","PeriodicalId":100245,"journal":{"name":"Circular Economy","volume":"3 3","pages":"Article 100101"},"PeriodicalIF":0.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2773167724000293/pdfft?md5=9d3b343e2bfd0cdd2cc1fec51d483f3f&pid=1-s2.0-S2773167724000293-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142172095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Malachite green dye removal with aluminosilicate nanopowder from aluminum dross and silicomanganese slag","authors":"Mostafa Mahinroosta ,&nbsp;Rozita M Moattari ,&nbsp;Ali Allahverdi ,&nbsp;Pooria Ghadir","doi":"10.1016/j.cec.2024.100100","DOIUrl":"10.1016/j.cec.2024.100100","url":null,"abstract":"<div><p>Malachite green is a persistent, bioaccumulative, mutagenic, carcinogenic, and teratogenic dye that poses significant risks in water sources, making its removal from water a critical necessity. This study aims to fabricate a sorbent comprising amorphous aluminosilicate nanopowder utilizing silicomanganese slag (SMS) and secondary aluminum dross (SAD) waste materials to remediate dye-contaminated water. The silica and alumina components of the SMS and SAD were extracted as sodium silicate and sodium aluminate leachates, respectively, through an effective hydrometallurgical conversion process. An empirical formula of Al₂O₃·2.3SiO₂ was deduced from the X-ray fluorescence analysis of the synthesized material. The X-ray diffraction (XRD) pattern indicated the amorphous nature of the synthesized aluminosilicate, with no evidence of nanocrystals or ordered clusters observed via high-resolution transmission electron microscopy (TEM). Based on TEM micrographs, the aluminosilicate particles ranged in size from 20 to 80 nm. The synthesized aluminosilicate nanopowder was utilized to treat wastewater containing malachite green dye, demonstrating a remarkable dye removal efficiency of 97% after a 15-min contact time using 30 mg of adsorbent in a 30 mL dye solution at 200 rpm. The methodology proposed in this study could facilitate the production of amorphous aluminosilicate powder as a high-value product from industrial waste. Studies on its reusability demonstrated that it could remove over 90% of the dye after three cycles of use.</p></div>","PeriodicalId":100245,"journal":{"name":"Circular Economy","volume":"3 3","pages":"Article 100100"},"PeriodicalIF":0.0,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2773167724000281/pdfft?md5=8d7c68ca5080d1a4a6f37f07c3eba6f3&pid=1-s2.0-S2773167724000281-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142087131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distribution, occurrence, and environmental risks of heavy metals in hazardous waste: A regional study in Beijing, China","authors":"Dan Wu ,&nbsp;Yanjun Liu ,&nbsp;Lingyi Meng ,&nbsp;Guilan lu ,&nbsp;Yazhuo Chen ,&nbsp;Ziliang Yang","doi":"10.1016/j.cec.2024.100099","DOIUrl":"10.1016/j.cec.2024.100099","url":null,"abstract":"<div><p>Hazardous waste from industrial production has become a global concern because of its impact on the environment and human health. However, studies on heavy metals in regional hazardous waste are rare. Thus, this study examined 93 hazardous waste samples in Beijing in 2019, to assess the distribution, occurrence, and potential eco-environmental risks of heavy metals in such waste. The results indicated high concentrations of Zn, Cu, and Ni in hazardous waste, and the leaching toxicity of Ni (270.60 mg/L), Cu (524.1 mg/L), and Pb (136.23 mg/L) exceeded Chinese identification standards for hazardous waste. Heavy metals in hazardous waste have been primarily found in remote counties around the locations of industrial enterprises. The total amount of the heavy metals followed the order: Zn &gt; Cu &gt; Ni &gt; Ba &gt; Mn &gt; Pb. Based on the migration abilities of their detected forms, heavy metals were classified into three categories (high, middle, and low migration abilities) to characterize their potential to enter the environment. The detected amounts of heavy metals with high and middle migration ability followed the order: Zn &gt; Cu &gt; Ni &gt; Mn &gt; Pb &gt; Ba. The potential environmental risk of heavy metals was evaluated using the potential environmental risk index, resulting in the following ranking: Ni &gt; Pb &gt; Mn &gt; Zn &gt; Cu &gt; Ba. Daxing District exhibited the highest total environmental risk and environmental risk per unit area, whereas Miyun District showed the highest environmental risk per secondary sector of the economy and unit of GDP. This was attributed to Beijing's industrial structure. The results of this study provide fundamental data for the management and control of hazardous waste in Beijing and are expected to aid in preventing and managing environmental risks caused by such waste.</p></div>","PeriodicalId":100245,"journal":{"name":"Circular Economy","volume":"3 3","pages":"Article 100099"},"PeriodicalIF":0.0,"publicationDate":"2024-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S277316772400027X/pdfft?md5=6999769d6190ce8c74d5de7f91053d8e&pid=1-s2.0-S277316772400027X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142087130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"What Can We Learn From the Bankruptcy of Renewcell? Some Limitations of Business-Case-Based Circular Transition","authors":"Hervé Corvellec, Alison F. Stowell","doi":"10.55845/tfhb2038","DOIUrl":"https://doi.org/10.55845/tfhb2038","url":null,"abstract":"Circular start-ups are vectors of hope for a circular transition. But what does a circular champion’s bankruptcy tell us? That a structural barrier to the circular transition is the total dependence on the ability of circular businesses to be profitable.","PeriodicalId":100245,"journal":{"name":"Circular Economy","volume":"23 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141710653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"What is the University For These Days? Rethinking the Foundations of the ‘Circular Campus’","authors":"K. Hobson, Megan O’Byrne","doi":"10.55845/bdcu6970","DOIUrl":"https://doi.org/10.55845/bdcu6970","url":null,"abstract":"In line with growing concerns about the negative environmental impacts of Higher Education Institutions’ (HEIs) core activities, Circular Economy (CE) interventions are appearing across campuses, focussing on e.g., curriculum content, operations, and resource-use, and/or research. In parallel, researchers are increasingly exploring the aims, barriers, processes, and outcomes of attempts to make HEIs more ‘circular’. However, this growing literature often fails to connect with broader critiques of prevailing CE goals and processes, to consider the types of CE being enacted and if other forms of CE are possible and desirable in HEIs. In response, this paper discusses data from research interviews undertaken as part of a project that explored on-campus CE initiatives at a sample of UK and Irish HEIs. It reports on key interview themes, which are HEIs as spaces of over-consumption; as testbeds for new CE practices: and as sites of CE degrowth: and makes the case for HEIs to ask fundamental, radical questions—i.e., ‘what is the university for these days?’—as a pivotal part of CE projects and systems across HEIs.","PeriodicalId":100245,"journal":{"name":"Circular Economy","volume":"74 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141694539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The biofactories: Quantifying environmental benefits of the wastewater circular economy in Chile using life cycle assessment","authors":"","doi":"10.1016/j.cec.2024.100091","DOIUrl":"10.1016/j.cec.2024.100091","url":null,"abstract":"<div><p>The wastewater circular economy promises improved environmental impacts within the food-water-energy nexus. This requires verification as the global sanitation sectors seek to improve environmental impacts and achieve integrated water management. Life cycle assessment (LCA) has been used to compare novel technologies for wastewater treatment and recovery, but research addressing plant-wide improvements of co-product resource recovery using real data from full-scale plants is still needed, particularly in a Latin American context. In Chile, two wastewater treatment plants (WWTPs) have embraced the circular economy configuration, recovering treated effluent, biosolids, and biogas, in addition to implementing advanced nitrogen removal using different technologies. The LCA of these two WWTPs demonstrated that Plant A improved 8 out of 10 impact categories compared to the baseline conventional scenario, while Plant B improved 5 categories out of 10. The analysis of the two plants showed the influence of influent quality on environmental impacts and the trade-off that occurs between the different technologies implemented. Plant B generated larger environmental credits through increased biogas and biosolids recovery due to thermal hydrolysis pre-treatment and anaerobic digestion, combined with cogeneration of heat and power. Plant A implemented water recovery, which provided benefits on a smaller magnitude but to more impact categories. Therefore, both plants improved environmental impacts through the wastewater circular economy, but further improvements in system configurations are recommended in each.</p></div>","PeriodicalId":100245,"journal":{"name":"Circular Economy","volume":"3 3","pages":"Article 100091"},"PeriodicalIF":0.0,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2773167724000190/pdfft?md5=f1c627d85fb6e627eb411bd17fe5b167&pid=1-s2.0-S2773167724000190-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141397333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rethinking Regional Embeddedness and Innovation Systems for Transitions Towards Just, Responsible, and Circular Bioeconomies","authors":"Michael P. Schlaile, Jonathan Friedrich, J. Zscheischler","doi":"10.55845/dtfi9420","DOIUrl":"https://doi.org/10.55845/dtfi9420","url":null,"abstract":"Few studies have explicitly explored regional embeddedness and both the inconsistencies and injustices of circular bioeconomy (CBE) innovations. To better navigate the normative dimension of these innovations and CBE transitions in general, our article presents a threefold argument for the relevance of the regional level of analysis. First, CBE innovations are influenced by and affect regional metabolisms and actor constellations, assets, and (biophysical) resources within regional innovation systems (RIS). Second, thoroughly exploring these dimensions of regional (un)embeddedness can reveal ethical concerns, including potential \"dark sides\" and injustices, such as exclusivity and exploitation. Third, to address these concerns in CBE research and governance, we outline four facets: complementing the RIS as a framework and policy approach, balancing creative and destructive measures, addressing the need for more inclusive regional CBE policies, and establishing dedicated intermediaries to better govern regional CBE transitions. In summary, this conceptual article provides starting points for further research and proactive measures that help govern the normative dimension and the design of CBE transitions at the regional level, promoting inclusivity, justice, responsibility, and legitimacy for both innovation and exnovation.","PeriodicalId":100245,"journal":{"name":"Circular Economy","volume":"9 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141234005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}