Pub Date : 2024-11-05DOI: 10.1016/j.jclepro.2024.144030
E-commerce serves as an important link between the digital economy and the real economy, and contributes positively to income growth. In the face of resource constraints and serious environmental pollution, it is equally relevant to examine the environmental effects of e-commerce. Based on county panel data for China from 2011 to 2018, this study uses a difference in differences (DID) model to investigate the impact of Rural E-Commerce Demonstration County (REDC) policy on air pollution. This study reveals that the demonstration policy exacerbates air pollution in counties and the pollution effect is regionally heterogeneous. Additionally, the increase in temperature and precipitation weakens the pollution effects of the demonstration policy. Mechanism analysis indicates that the demonstration policy can promote the development of the secondary industry and digital financial inclusion at the county level, which subsequently leads to the deterioration of local air quality. Further analysis of costs and benefits reveals that the significant positive economic effects resulting from the demonstration policy far outweigh the indirect economic losses caused by air pollution. Therefore, when local governments actively promote the development of e-commerce in rural areas, they should also attach great importance to its potential negative environmental externalities.
{"title":"E-commerce and air pollution: Evidence from China","authors":"","doi":"10.1016/j.jclepro.2024.144030","DOIUrl":"10.1016/j.jclepro.2024.144030","url":null,"abstract":"<div><div>E-commerce serves as an important link between the digital economy and the real economy, and contributes positively to income growth. In the face of resource constraints and serious environmental pollution, it is equally relevant to examine the environmental effects of e-commerce. Based on county panel data for China from 2011 to 2018, this study uses a difference in differences (DID) model to investigate the impact of Rural E-Commerce Demonstration County (REDC) policy on air pollution. This study reveals that the demonstration policy exacerbates air pollution in counties and the pollution effect is regionally heterogeneous. Additionally, the increase in temperature and precipitation weakens the pollution effects of the demonstration policy. Mechanism analysis indicates that the demonstration policy can promote the development of the secondary industry and digital financial inclusion at the county level, which subsequently leads to the deterioration of local air quality. Further analysis of costs and benefits reveals that the significant positive economic effects resulting from the demonstration policy far outweigh the indirect economic losses caused by air pollution. Therefore, when local governments actively promote the development of e-commerce in rural areas, they should also attach great importance to its potential negative environmental externalities.</div></div>","PeriodicalId":349,"journal":{"name":"Journal of Cleaner Production","volume":null,"pages":null},"PeriodicalIF":9.7,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-05DOI: 10.1016/j.jclepro.2024.144158
A.E. Schwarz, S.M.C. Lensen, S.D.M. Herlaar, T. van Harmelen, P.H. Stegmann
The circular economy (CE) was introduced as a solution to mitigate increasing resource demand and to reduce environmental impacts. However, it remains a challenge to holistically assess long-term environmental impacts of CE strategies in complex, dynamic systems. To tackle this issue, we present the Circular Industrial Transformation System (CITS) model. CITS integrates dynamic stock modelling, material flow analysis and prospective life cycle assessment while being flexibly applicable to different products, materials and industry sectors across temporal and spatial scales. With that, the CITS model can assess the effect of circular strategies on long-term material flows and their respective environmental impacts, while including the effects of socio-economic developments, transformative climate policies, and a changing energy system. As a case study, the environmental impact reduction of both CE and climate change mitigation strategies was assessed for the German passenger car fleet until 2050. The results indicate that the occurring electrification of the passenger fleet is an effective strategy for reducing the global warming impacts of the automotive sector in the long-term, albeit aligned with the renewable energy transformation. CE strategies are most effective in reducing CO2-eq. emissions in the short term. Particularly, CE strategies affecting the vehicle stock promise substantial reductions in CO2-eq. emissions and primary material demand, while improved collection, sorting, and recycling have a limited impact. The results show that the CITS model can guide policies in effectively reducing environmental impacts in complex, dynamic systems by identifying system bottlenecks, trade-offs or synergies in industrial transitions.
{"title":"The Circular Industrial Transformation System (CITS) model - assessing the life cycle impacts of climate and circularity strategies","authors":"A.E. Schwarz, S.M.C. Lensen, S.D.M. Herlaar, T. van Harmelen, P.H. Stegmann","doi":"10.1016/j.jclepro.2024.144158","DOIUrl":"https://doi.org/10.1016/j.jclepro.2024.144158","url":null,"abstract":"The circular economy (CE) was introduced as a solution to mitigate increasing resource demand and to reduce environmental impacts. However, it remains a challenge to holistically assess long-term environmental impacts of CE strategies in complex, dynamic systems. To tackle this issue, we present the Circular Industrial Transformation System (CITS) model. CITS integrates dynamic stock modelling, material flow analysis and prospective life cycle assessment while being flexibly applicable to different products, materials and industry sectors across temporal and spatial scales. With that, the CITS model can assess the effect of circular strategies on long-term material flows and their respective environmental impacts, while including the effects of socio-economic developments<em>,</em> transformative climate policies, and a changing energy system<em>.</em> As a case study, the environmental impact reduction of both CE and climate change mitigation strategies was assessed for the German passenger car fleet until 2050. The results indicate that the occurring electrification of the passenger fleet is an effective strategy for reducing the global warming impacts of the automotive sector in the long-term, albeit aligned with the renewable energy transformation. CE strategies are most effective in reducing CO<sub>2</sub>-eq. emissions in the short term. Particularly, CE strategies affecting the vehicle stock promise substantial reductions in CO<sub>2</sub>-eq. emissions and primary material demand, while improved collection, sorting, and recycling have a limited impact. The results show that the CITS model can guide policies in effectively reducing environmental impacts in complex, dynamic systems by identifying system bottlenecks, trade-offs or synergies in industrial transitions.","PeriodicalId":349,"journal":{"name":"Journal of Cleaner Production","volume":null,"pages":null},"PeriodicalIF":11.1,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142579996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-04DOI: 10.1016/j.jclepro.2024.144151
Christos Spandonidis, Maria-Paraskevi Belioka, Ola Eriksson
Greenhouse Gas (GHG) emissions significantly impact the environment and human health, but many people are unaware of how their daily choices affect climate change. Carbon calculators estimate emissions in sectors like construction, digital health, transportation, and food production. However, they are still developing and face challenges that require attention from both industry and academia. Researchers highlight the absence of a unified framework for assessing these tools, leading to simplistic binary evaluations, which result in inaccuracies in household tool evaluations. In the current study, an assessment framework has been created by integrating existing binary frameworks and incorporating the MCDA method for weighted multi-criteria evaluation, offering a quantitative scoring system for qualitative criteria. This dual-criteria framework addresses both practical and academic aspects of the evaluated tools. The framework was used to evaluate 15 tools chosen for their prominence in search engine results and their impact on scientific publications. Findings revealed that tools such as Svalna, WWF calculator, and Carbon Savvy produce comparable results, while others, like the UN CF calculator, show deviations up to 136 tons. The study highlights challenges related to feasibility, availability of resources, and user engagement, noting that the criterion for accessibility for special groups received a score of zero across all CF tools. The work is expected to yield enhanced understanding that will aid in the selection of appropriate CF tools, foster sustainable practices, and offer developers direction to ensure their designs conform to established standards.
{"title":"Multi-criteria-based evaluation of digital Carbon Footprint tools from a household user perspective.","authors":"Christos Spandonidis, Maria-Paraskevi Belioka, Ola Eriksson","doi":"10.1016/j.jclepro.2024.144151","DOIUrl":"https://doi.org/10.1016/j.jclepro.2024.144151","url":null,"abstract":"Greenhouse Gas (GHG) emissions significantly impact the environment and human health, but many people are unaware of how their daily choices affect climate change. Carbon calculators estimate emissions in sectors like construction, digital health, transportation, and food production. However, they are still developing and face challenges that require attention from both industry and academia. Researchers highlight the absence of a unified framework for assessing these tools, leading to simplistic binary evaluations, which result in inaccuracies in household tool evaluations. In the current study, an assessment framework has been created by integrating existing binary frameworks and incorporating the MCDA method for weighted multi-criteria evaluation, offering a quantitative scoring system for qualitative criteria. This dual-criteria framework addresses both practical and academic aspects of the evaluated tools. The framework was used to evaluate 15 tools chosen for their prominence in search engine results and their impact on scientific publications. Findings revealed that tools such as Svalna, WWF calculator, and Carbon Savvy produce comparable results, while others, like the UN CF calculator, show deviations up to 136 tons. The study highlights challenges related to feasibility, availability of resources, and user engagement, noting that the criterion for accessibility for special groups received a score of zero across all CF tools. The work is expected to yield enhanced understanding that will aid in the selection of appropriate CF tools, foster sustainable practices, and offer developers direction to ensure their designs conform to established standards.","PeriodicalId":349,"journal":{"name":"Journal of Cleaner Production","volume":null,"pages":null},"PeriodicalIF":11.1,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142579998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-04DOI: 10.1016/j.jclepro.2024.144145
Zhenhua Duan, Wenjing Zhao, Taohua Ye, Jianzhuang Xiao
This study investigates the influence of carbonated recycled concrete powder (CRCP), alkali content (AC), and silicate modulus (SM) on the compressive strength, chemical composition, and environmental benefits of CRCP-blast furnace slag blended alkali-activated binders (AABs). The results show that increasing CRCP content reduces the compressive strength of AABs due to lower geopolymeric reactivity. Using response surface methodology, the optimal values for AC and SM in AABs containing 50 wt.% CRCP were determined as 14.28% and 0.92, respectively, resulting in predicted and actual strengths of 49.9 MPa and 46.8 MPa. Chemical analyses reveal that calcite and vaterite are the predominant crystalline phases in AABs, while both Si-Al gels and calcite from CRCP participate in geopolymeric reactions. The effects of AC and SM on AAB strength are further elucidated through the combined analysis of precursor dissolution amount, geopolymeric gel formation amount, and calcium carbonate decomposition amount. Moreover, CRCP demonstrates negative carbon emissions, with a global warming potential of -0.16 kg CO2 eq/kg. The optimally proportioned AAB containing 50 wt.% CRCP shows global warming potential and carbon intensity values significantly lower than those of Portland cement, at 54.4% and 50.8%, respectively. These findings emphasize that AABs containing 50 wt.% CRCP not only meet the 43-grade strength classification but also offer notable environmental benefits. In summary, this study contributes to the development of a novel 43-graded low-carbon binder containing high-volume CRCP.
{"title":"Performance optimization and environmental assessment of novel alkali-activated binders containing carbonated recycled concrete powder","authors":"Zhenhua Duan, Wenjing Zhao, Taohua Ye, Jianzhuang Xiao","doi":"10.1016/j.jclepro.2024.144145","DOIUrl":"https://doi.org/10.1016/j.jclepro.2024.144145","url":null,"abstract":"This study investigates the influence of carbonated recycled concrete powder (CRCP), alkali content (AC), and silicate modulus (SM) on the compressive strength, chemical composition, and environmental benefits of CRCP-blast furnace slag blended alkali-activated binders (AABs). The results show that increasing CRCP content reduces the compressive strength of AABs due to lower geopolymeric reactivity. Using response surface methodology, the optimal values for AC and SM in AABs containing 50 wt.% CRCP were determined as 14.28% and 0.92, respectively, resulting in predicted and actual strengths of 49.9 MPa and 46.8 MPa. Chemical analyses reveal that calcite and vaterite are the predominant crystalline phases in AABs, while both Si-Al gels and calcite from CRCP participate in geopolymeric reactions. The effects of AC and SM on AAB strength are further elucidated through the combined analysis of precursor dissolution amount, geopolymeric gel formation amount, and calcium carbonate decomposition amount. Moreover, CRCP demonstrates negative carbon emissions, with a global warming potential of -0.16 kg CO<sub>2</sub> eq/kg. The optimally proportioned AAB containing 50 wt.% CRCP shows global warming potential and carbon intensity values significantly lower than those of Portland cement, at 54.4% and 50.8%, respectively. These findings emphasize that AABs containing 50 wt.% CRCP not only meet the 43-grade strength classification but also offer notable environmental benefits. In summary, this study contributes to the development of a novel 43-graded low-carbon binder containing high-volume CRCP.","PeriodicalId":349,"journal":{"name":"Journal of Cleaner Production","volume":null,"pages":null},"PeriodicalIF":11.1,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142580054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-04DOI: 10.1016/j.jclepro.2024.144002
Mauro Fracarolli Nunes, Camila Lee Park, Jose A.D. Machuca
The authors regret < not having indicated in the publication of the article which are the financing entities and the projects in which this article is framed. That is why these are indicated in this corrigendum:
作者很遗憾没有在文章发表时说明本文所涉及的融资实体和项目。因此，在本更正中予以说明：
{"title":"Corrigendum to “Strategic incentives and natural capital accounting for sustainable supply chain management: Measuring reputational impacts and consumers’ perceptions of the use of water through behavioural experimental studies” [J. Clean. Prod. 475 (2024) 143621]","authors":"Mauro Fracarolli Nunes, Camila Lee Park, Jose A.D. Machuca","doi":"10.1016/j.jclepro.2024.144002","DOIUrl":"https://doi.org/10.1016/j.jclepro.2024.144002","url":null,"abstract":"The authors regret < not having indicated in the publication of the article which are the financing entities and the projects in which this article is framed. That is why these are indicated in this corrigendum:","PeriodicalId":349,"journal":{"name":"Journal of Cleaner Production","volume":null,"pages":null},"PeriodicalIF":11.1,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142574277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-04DOI: 10.1016/j.jclepro.2024.144148
Mingying Yang, Yufu Chen, Yuanyuan Yang, Yuxing Yan
Achieving the United Nations' Sustainable Development Goals requires a healthy ecological environment, which is fundamental to human well-being. Although ecosystem services (ESs) exhibit a close relationship with land use intensity (LUI), most studies examining this relationship focus on the aspect of ESs supply. There is still sparse research on understanding this relationship from the perspective of ecosystem service supply-demand ratio (ESSDR) that can reflect ESs supply-demand equilibrium state. Particularly, the nonlinear interaction and threshold between ESSDR and LUI remain underexplored. To address the research gap, this study quantified ESSDR and LUI in the Beijing-Tianjin-Hebei region (BTH) of China, and identified their nonlinear relationship and threshold using constraint line and the restricted cubic spline method. Results revealed the following findings: (1) During 2000-2020, the supply-demand ratios of grain production (GP-SDR), carbon sequestration (CS-SDR), and habitat quality (HQ-SDR) decreased, whereas supply-demand ratios of water yield (WY-SDR) and leisure recreation (LR-SDR) increased. (2) The average LUI increased slightly from 2.91 in 2000 to 3.02 in 2020, with areas of high LUI clustered in southeastern central urban areas, illustrating a core-edge distribution pattern. (3) ESSDR and LUI displayed complex nonlinear relationships, with the constraint lines showing inverted U-shaped between WY-SDR, GP-SDR, and LUI, steep descent curves between CS-SDR, HQ-SDR, and LUI, and U-shaped between LR-SDR and LUI, respectively. Certain thresholds were observed, such as GP-SDR dropping notably as LUI exceeded 3.5, while LR-SDR increased around LUI 3.7. Finally, the BTH region was divided into core control areas, general control areas, and maintenance areas based on identified thresholds, with tailored suggestions being provided to facilitate human-environment coordination within different threshold areas. This study can deepen the comprehension of the intricate interplay between ESSDR and LUI, and offer scientific reference for sustainable land use management and eco-environment conservation.
实现联合国可持续发展目标需要一个健康的生态环境，这是人类福祉的基础。虽然生态系统服务（ES）与土地利用强度（LUI）有着密切的关系，但研究这种关系的大多数研究都集中在生态系统服务供应方面。从能反映生态系统服务供需平衡状态的生态系统服务供需比（ESSDR）角度来理解这种关系的研究还很少。特别是，ESSDR 与 LUI 之间的非线性相互作用和阈值仍未得到充分探讨。针对这一研究空白，本研究对中国京津冀地区（BTH）的ESSDR 和 LUI 进行了量化，并利用约束线和受限三次样条法确定了它们之间的非线性关系和临界值。结果表明：（1）2000-2020 年间，粮食产量（GP-SDR）、碳汇（CS-SDR）和栖息地质量（HQ-SDR）的供需比下降，而水资源产量（WY-SDR）和休闲娱乐（LR-SDR）的供需比上升。(2) 平均 LUI 略有增加，从 2000 年的 2.91 增加到 2020 年的 3.02，高 LUI 区域集中在东南部中心城区，呈现核心-边缘分布模式。(3) ESSDR 和 LUI 呈现复杂的非线性关系，约束线分别在 WY-SDR、GP-SDR 和 LUI 之间呈现倒 U 型，在 CS-SDR、HQ-SDR 和 LUI 之间呈现陡峭的下降曲线，在 LR-SDR 和 LUI 之间呈现 U 型。观察到了某些阈值，例如当 LUI 超过 3.5 时，GP-SDR 明显下降，而 LR-SDR 则在 LUI 3.7 附近上升。最后，根据确定的阈值，将 BTH 区域划分为核心控制区、一般控制区和维护区，并提出有针对性的建议，以促进不同阈值区域内的人与环境协调。本研究可加深对 ESSDR 与 LUI 之间错综复杂的相互作用的理解，为可持续土地利用管理和生态环境保护提供科学参考。
{"title":"Nonlinear relationship and threshold-based zones between ecosystem service supply-demand ratio and land use intensity: A case study of the Beijing-Tianjin-Hebei region, China","authors":"Mingying Yang, Yufu Chen, Yuanyuan Yang, Yuxing Yan","doi":"10.1016/j.jclepro.2024.144148","DOIUrl":"https://doi.org/10.1016/j.jclepro.2024.144148","url":null,"abstract":"Achieving the United Nations' Sustainable Development Goals requires a healthy ecological environment, which is fundamental to human well-being. Although ecosystem services (ESs) exhibit a close relationship with land use intensity (LUI), most studies examining this relationship focus on the aspect of ESs supply. There is still sparse research on understanding this relationship from the perspective of ecosystem service supply-demand ratio (ESSDR) that can reflect ESs supply-demand equilibrium state. Particularly, the nonlinear interaction and threshold between ESSDR and LUI remain underexplored. To address the research gap, this study quantified ESSDR and LUI in the Beijing-Tianjin-Hebei region (BTH) of China, and identified their nonlinear relationship and threshold using constraint line and the restricted cubic spline method. Results revealed the following findings: (1) During 2000-2020, the supply-demand ratios of grain production (GP-SDR), carbon sequestration (CS-SDR), and habitat quality (HQ-SDR) decreased, whereas supply-demand ratios of water yield (WY-SDR) and leisure recreation (LR-SDR) increased. (2) The average LUI increased slightly from 2.91 in 2000 to 3.02 in 2020, with areas of high LUI clustered in southeastern central urban areas, illustrating a core-edge distribution pattern. (3) ESSDR and LUI displayed complex nonlinear relationships, with the constraint lines showing inverted U-shaped between WY-SDR, GP-SDR, and LUI, steep descent curves between CS-SDR, HQ-SDR, and LUI, and U-shaped between LR-SDR and LUI, respectively. Certain thresholds were observed, such as GP-SDR dropping notably as LUI exceeded 3.5, while LR-SDR increased around LUI 3.7. Finally, the BTH region was divided into core control areas, general control areas, and maintenance areas based on identified thresholds, with tailored suggestions being provided to facilitate human-environment coordination within different threshold areas. This study can deepen the comprehension of the intricate interplay between ESSDR and LUI, and offer scientific reference for sustainable land use management and eco-environment conservation.","PeriodicalId":349,"journal":{"name":"Journal of Cleaner Production","volume":null,"pages":null},"PeriodicalIF":11.1,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142574561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-04DOI: 10.1016/j.jclepro.2024.144149
Jiaqi Lv, Qingliang Zhao, Junqiu Jiang, Jing Ding, Liangliang Wei, Kun Wang
As improved and expanded wastewater treatment facilities, sludge dewatering is the essential process and major challenge due to the complex and abundant organic matter. Microbial fuel cell powered electro-Fenton system (MFCⓅEFs) has been demonstrated to generate •OH and destroy hydrophilic extracellular polymeric substances (EPS) as an improved method of high efficiency and low energy consumption. Nevertheless, the smaller particle size of the treated sludge and the release of partial organic matter into the supernatant can affect the sludge-water separation process. Chitosan quaternary ammonium salt (CQAS) as a renewable and biodegradability cationic coagulant can be involved in the follow-up treatment. The sludge after combined treatment exhibited better dewaterability, where the water content of sludge cake (WCSC), capillary suction time (CST), and specific resistance filtration (SRF) were 61.21%, 15.6 s, and 1.02×1012 m/kg (26.47%, 80.72% and 84.28% reduction), respectively. The oxidation of the MFCⓅEFs destroyed the cellular and EPS structure and the bridging flocculation and charge neutralization of CQAS caused the fine particles to squeeze each other. The combined treatment fully reduced the content of negative charge and hydrophilic substances on the surface, which affected the intensity change of N-H bond and altered the protein secondary structure to make it looser, thus releasing more bound water while improving aggregation characteristics. Overall, combined treatment can significantly improve sludge dewaterability and owns operational advantages of high efficiency, low energy and consumption, safety, and non-toxicity.
{"title":"Sludge dewaterability improvement in microbial fuel cell powered electro-Fenton system (MFCⓅEFs) coupled with chitosan quaternary ammonium salt","authors":"Jiaqi Lv, Qingliang Zhao, Junqiu Jiang, Jing Ding, Liangliang Wei, Kun Wang","doi":"10.1016/j.jclepro.2024.144149","DOIUrl":"https://doi.org/10.1016/j.jclepro.2024.144149","url":null,"abstract":"As improved and expanded wastewater treatment facilities, sludge dewatering is the essential process and major challenge due to the complex and abundant organic matter. Microbial fuel cell powered electro-Fenton system (MFCⓅEFs) has been demonstrated to generate •OH and destroy hydrophilic extracellular polymeric substances (EPS) as an improved method of high efficiency and low energy consumption. Nevertheless, the smaller particle size of the treated sludge and the release of partial organic matter into the supernatant can affect the sludge-water separation process. Chitosan quaternary ammonium salt (CQAS) as a renewable and biodegradability cationic coagulant can be involved in the follow-up treatment. The sludge after combined treatment exhibited better dewaterability, where the water content of sludge cake (WC<sub>SC</sub>), capillary suction time (CST), and specific resistance filtration (SRF) were 61.21%, 15.6 s, and 1.02×10<sup>12</sup> m/kg (26.47%, 80.72% and 84.28% reduction), respectively. The oxidation of the MFCⓅEFs destroyed the cellular and EPS structure and the bridging flocculation and charge neutralization of CQAS caused the fine particles to squeeze each other. The combined treatment fully reduced the content of negative charge and hydrophilic substances on the surface, which affected the intensity change of N-H bond and altered the protein secondary structure to make it looser, thus releasing more bound water while improving aggregation characteristics. Overall, combined treatment can significantly improve sludge dewaterability and owns operational advantages of high efficiency, low energy and consumption, safety, and non-toxicity.","PeriodicalId":349,"journal":{"name":"Journal of Cleaner Production","volume":null,"pages":null},"PeriodicalIF":11.1,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142574562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-04DOI: 10.1016/j.jclepro.2024.144152
Mei Chang, Zeshui Xu, Xunjie Gou
Facilitating coordination between economic growth and carbon mitigation is vital for the sustainability of human society. Identifying the driving factors of Carbon emission performance (CEP) is crucial for its improvement. Nevertheless, empirical research on the relationship between advanced human capital structure (AHCS) and CEP remains scarce. This study analyzes the impact of AHCS on CEP utilizing a dataset covering 30 Chinese provinces from 2006 to 2021. First, we construct a global epsilon-based measure (EBM) model with undesired output to accurately measure the multi-period CEP for Chinese provinces. Next, we evaluate the level of AHCS from the perspective of dynamic evolution. Subsequently, a spatial Durbin model (SDM) is employed to examine the spatial spillover effects of AHCS on CEP. The results illustrate that CEP exhibits significant positive spatial spillover effects across provinces. Additionally, AHCS has a direct and significant positive impact on local CEP and can indirectly enhance CEP in neighboring regions through spillover effects, although the impact varies across different regions. The impact mechanism analysis indicates that AHCS enhances CEP via technological advancement, industrial structure upgrading (ISU), and energy efficiency improvement, despite the asymmetric effects observed between local and neighboring provinces. Therefore, shaping a favorable educational environment to optimize the human capital structure is critical for the improvement of CEP. In addition, promoting resource sharing and technology exchange through regional cooperation is essential for China’s low-carbon transition development.
{"title":"Does advanced human capital structure improve carbon emission performance in China? Empirical research from a spatial spillover perspective","authors":"Mei Chang, Zeshui Xu, Xunjie Gou","doi":"10.1016/j.jclepro.2024.144152","DOIUrl":"https://doi.org/10.1016/j.jclepro.2024.144152","url":null,"abstract":"Facilitating coordination between economic growth and carbon mitigation is vital for the sustainability of human society. Identifying the driving factors of Carbon emission performance (CEP) is crucial for its improvement. Nevertheless, empirical research on the relationship between advanced human capital structure (AHCS) and CEP remains scarce. This study analyzes the impact of AHCS on CEP utilizing a dataset covering 30 Chinese provinces from 2006 to 2021. First, we construct a global epsilon-based measure (EBM) model with undesired output to accurately measure the multi-period CEP for Chinese provinces. Next, we evaluate the level of AHCS from the perspective of dynamic evolution. Subsequently, a spatial Durbin model (SDM) is employed to examine the spatial spillover effects of AHCS on CEP. The results illustrate that CEP exhibits significant positive spatial spillover effects across provinces. Additionally, AHCS has a direct and significant positive impact on local CEP and can indirectly enhance CEP in neighboring regions through spillover effects, although the impact varies across different regions. The impact mechanism analysis indicates that AHCS enhances CEP via technological advancement, industrial structure upgrading (ISU), and energy efficiency improvement, despite the asymmetric effects observed between local and neighboring provinces. Therefore, shaping a favorable educational environment to optimize the human capital structure is critical for the improvement of CEP. In addition, promoting resource sharing and technology exchange through regional cooperation is essential for China’s low-carbon transition development.","PeriodicalId":349,"journal":{"name":"Journal of Cleaner Production","volume":null,"pages":null},"PeriodicalIF":11.1,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142580035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The blocking between terrestrial and riverine ecosystems by impermeable concrete can cause negative impacts on plant growth, water quality, and biodiversity in riparian zones. Herein, pursuing a balance among mechanical, planting, and water purification property, chitosan/biochar-modified eco-concrete (CBEC) was prepared as a new sustainable alternative for riparian protection, ecological restoration and water quality improvement. Compressive strength of CBEC with an optimized chitosan/biochar content of 6% could reach up to 14.05 MPa, meeting the requirements for stabilizing riparian slopes. Micromorphology characterization and porosity measurement (29.63%) confirmed the abundantly porous structure of CBEC, facilitating the soil-water nutrient exchange, plant growth and microbial attachment. The 30-d water tank cultivation observed that the physiological parameters of T. orientalis planted in CBEC, including biomass, chlorophyll, protein and starch, were greatly improved compared to unmodified eco-concrete (EC). Moreover, compared to EC, biochar-modified EC and chitosan-modified EC, the planting CBEC could most effectively decrease the levels of TN, NH4+-N, TP, and COD by 53.82%, 62.50%, 88.31%, and 57.95%, respectively. Specially, the planting CBEC could degrade a common but recalcitrant pesticide nitenpyram (NTP) by 32.83% into low-toxic substances, recognized by LC-MS analysis. Microbiological analysis revealed that CBEC greatly promoted the proliferation of both nutrient-transforming bacteria (e.g., Nitrospira and Pseudomonas) and some specific species dominating NTP degradation (e.g., Rhodococcus and Bacillus). Also, PICRUSt2 prediction results identified the enrichment of functional genes related to nitrogen and phosphorus transformation. Our findings can not only develop a superior multi-performance eco-concrete material but also provide a promising strategy for sustainable riparian restoration.
{"title":"A novel chitosan/biochar-modified eco-concrete with balanced mechanical, planting, and water purification performance for riparian restoration","authors":"Fanrun Huang, Shengxiang Rong, Shiqiang Tao, Hongqiang Chu, Huajie Huang, Shuaixiao Gao, Xin Zhang, Xinyan Xiong, Chi Zhang","doi":"10.1016/j.jclepro.2024.144144","DOIUrl":"https://doi.org/10.1016/j.jclepro.2024.144144","url":null,"abstract":"The blocking between terrestrial and riverine ecosystems by impermeable concrete can cause negative impacts on plant growth, water quality, and biodiversity in riparian zones. Herein, pursuing a balance among mechanical, planting, and water purification property, chitosan/biochar-modified eco-concrete (CBEC) was prepared as a new sustainable alternative for riparian protection, ecological restoration and water quality improvement. Compressive strength of CBEC with an optimized chitosan/biochar content of 6% could reach up to 14.05 MPa, meeting the requirements for stabilizing riparian slopes. Micromorphology characterization and porosity measurement (29.63%) confirmed the abundantly porous structure of CBEC, facilitating the soil-water nutrient exchange, plant growth and microbial attachment. The 30-d water tank cultivation observed that the physiological parameters of <em>T. orientalis</em> planted in CBEC, including biomass, chlorophyll, protein and starch, were greatly improved compared to unmodified eco-concrete (EC). Moreover, compared to EC, biochar-modified EC and chitosan-modified EC, the planting CBEC could most effectively decrease the levels of TN, NH<sub>4</sub><sup>+</sup>-N, TP, and COD by 53.82%, 62.50%, 88.31%, and 57.95%, respectively. Specially, the planting CBEC could degrade a common but recalcitrant pesticide nitenpyram (NTP) by 32.83% into low-toxic substances, recognized by LC-MS analysis. Microbiological analysis revealed that CBEC greatly promoted the proliferation of both nutrient-transforming bacteria (e.g., <em>Nitrospira</em> and <em>Pseudomonas</em>) and some specific species dominating NTP degradation (e.g., <em>Rhodococcus</em> and <em>Bacillus</em>). Also, PICRUSt2 prediction results identified the enrichment of functional genes related to nitrogen and phosphorus transformation. Our findings can not only develop a superior multi-performance eco-concrete material but also provide a promising strategy for sustainable riparian restoration.","PeriodicalId":349,"journal":{"name":"Journal of Cleaner Production","volume":null,"pages":null},"PeriodicalIF":11.1,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142580034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-04DOI: 10.1016/j.jclepro.2024.144155
Hui Wang, Jingpu Zhu, Tao Chen, Yufeng Tang, Dengke Zhang, Xu Wang, Juan Xie, Shuihui Wu, Hui Xu, Pu Zhao, Jia Li
Waste crumb rubber composite modified asphalt (CRCMA), composed of base asphalt, waste rubber powder, and several additives (softener, activator, and cross-linking agent), has been shown to effectively improve asphalt properties. The interactions between the components in CRCMA are complex, involving molecular diffusion that significantly impacts its performance. The diffusion behavior in asphalt molecules will affect various properties of asphalt and the reasons for the different properties of asphalt can be explained by studying its diffusion mechanism. Therefore, understanding the diffusion mechanism of CRCMA is essential. The molecular dynamics simulation was employed to analyze the factors influencing the diffusion mechanism, using the diffusion coefficient as a key indicator of molecular mobility. The findings showed that the diffusion coefficient of the asphalt system decreased over time but increased with temperature. The rubber composition type also had a significant impact on diffusion, with butadiene rubber (BR) showing the highest coefficient, followed by natural rubber (NR), crumb rubber (CR), and styrene-butadiene rubber (SBR). The diffusion coefficient was the lowest and the diffusion rate was slowest after adding softeners. The diffusion coefficient increased slightly with the addition of CR, and the diffusion rate was slightly accelerated but not significantly. The diffusion coefficient increased rapidly with adding activator and the diffusion rate increased significantly. With the addition of cross-linking agent, the diffusion coefficient began to decrease and the diffusion rate became slower. The CRCMA microscopic performance tests indicated that the swelling effect of CR limits diffusion, while activators promote degradation and desulfurization of CR due to the large molecule structure getting smaller, enhancing diffusion. The S=O bond in the asphalt system was regenerated and re-crosslinked to create a mesh after adding the cross-linking agent. The small molecule structure was transformed into large one. The molecular diffusion was restricted partly and thus the diffusion rate was slowed down.
{"title":"Diffusion Mechanism of Waste Crumb Rubber Composite Modified Asphalt Based on Molecular Dynamics Simulation","authors":"Hui Wang, Jingpu Zhu, Tao Chen, Yufeng Tang, Dengke Zhang, Xu Wang, Juan Xie, Shuihui Wu, Hui Xu, Pu Zhao, Jia Li","doi":"10.1016/j.jclepro.2024.144155","DOIUrl":"https://doi.org/10.1016/j.jclepro.2024.144155","url":null,"abstract":"Waste crumb rubber composite modified asphalt (CRCMA), composed of base asphalt, waste rubber powder, and several additives (softener, activator, and cross-linking agent), has been shown to effectively improve asphalt properties. The interactions between the components in CRCMA are complex, involving molecular diffusion that significantly impacts its performance. The diffusion behavior in asphalt molecules will affect various properties of asphalt and the reasons for the different properties of asphalt can be explained by studying its diffusion mechanism. Therefore, understanding the diffusion mechanism of CRCMA is essential. The molecular dynamics simulation was employed to analyze the factors influencing the diffusion mechanism, using the diffusion coefficient as a key indicator of molecular mobility. The findings showed that the diffusion coefficient of the asphalt system decreased over time but increased with temperature. The rubber composition type also had a significant impact on diffusion, with butadiene rubber (BR) showing the highest coefficient, followed by natural rubber (NR), crumb rubber (CR), and styrene-butadiene rubber (SBR). The diffusion coefficient was the lowest and the diffusion rate was slowest after adding softeners. The diffusion coefficient increased slightly with the addition of CR, and the diffusion rate was slightly accelerated but not significantly. The diffusion coefficient increased rapidly with adding activator and the diffusion rate increased significantly. With the addition of cross-linking agent, the diffusion coefficient began to decrease and the diffusion rate became slower. The CRCMA microscopic performance tests indicated that the swelling effect of CR limits diffusion, while activators promote degradation and desulfurization of CR due to the large molecule structure getting smaller, enhancing diffusion. The S=O bond in the asphalt system was regenerated and re-crosslinked to create a mesh after adding the cross-linking agent. The small molecule structure was transformed into large one. The molecular diffusion was restricted partly and thus the diffusion rate was slowed down.","PeriodicalId":349,"journal":{"name":"Journal of Cleaner Production","volume":null,"pages":null},"PeriodicalIF":11.1,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142579997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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