Evaluating carbon emissions of China's waste management strategies for building refurbishment projects: contributing to a circular economy

Do circular economy, public-private Partnership and carbon policy manage the environmental stress? Developed countries' situation under the Prism of COP27

Since the Industrial Revolution, the economies have played well to make progress in economic growth. Besides, rapid growth has brought severe challenges, and environmental degradation is one of them. Therefore, the globe has introduced several green initiatives, such as the Kyoto Protocol, the Paris Agreement, and the Sustainable Development Goals, but the problem remains intact. Specifically, this study focuses on COP27 and highlights the key challenges and their best solutions. Undoubtedly, most nations have tried to meet their settled targets by 2030, but these have different priorities to facilitate their populace. Therefore, international cooperation has been introduced as a logical solution to collaborate across borders or within the region to deal with sustainability themes. However, developed nations have environmental problems due to industrial, income, and population growth, directly associated with environmental risks. Thus, under the SDGs, this empirical research tries to cover the critical problems (income, population aging, & industrial development) and their best alternative (public-private partnership, emission taxes & circular economy) to minimize environmental issues. Similarly, the current study utilizes an advanced series of estimators to investigate the study's objective for 17 developed nations from 2000 to 2021. Investigated outcomes describe income, population aging, and industrial activities that bring carbon emissions. Conversely, carbon policy and public-private partnerships support the sustainability theme for specified economies. Under the base model, the circular economy declines the environmental pressure by 0.016 %, 0.002 %, and 0.019 %, respectively, under the specified estimators. Moreover, this empirical research investigates the mediating role of carbon policy, public-private partnership & circular economy on industrial development. It brings a significant decline in emissions only for carbon policy & circular economy. However, this study also proposes some green policies to become clean & green shortly.

Waste-derived carbon nanostructures (WD-CNs): An innovative step toward waste to treasury

With the growing population, the accumulation of waste materials (WMs) (industrial/household waste) in the environment incessantly increases, affecting human health. Additionally, it affects the climate and ecosystem of terrestrial and water habitats, thereby needing effective management technology to control environmental pollution. In this aspect, managing these WMs to develop products that mitigate the associated issues is necessary. Researchers continue to focus on WMs management by adopting a circular economy. These WMs convert into useful/value-added products such as polymers and nanomaterials (NMs), especially carbon nanomaterials (CNs). The conversion/transformation of waste material into useful products is one of the best solutions for managing waste. Waste-derived CNs (WD-CNs) have established boundless promises for numerous applications like environmental remediation, energy, catalysts, sensors, and biomedical applications. This review paper discusses the several sources of waste material (agricultural, plastic, industrial, biomass, and other) transforming into WD-CNs, such as carbon nanotubes (CNTs), biochar, graphene, carbon nanofibers (CNFs), carbon dots, etc., are extensively elaborated and their application. The impact of metal doping within the WD-CNs is briefly discussed, along with their applicability to end applications.

Integrated and effective management of muck waste under the platform governance mode for a circular economy

As an inevitable part of construction and demolition (C&D) waste, muck has a dreadful environmental impact due its inadequate management by the traditional governance process. This paper therefore focuses on the management of muck generated from C&D waste by utilizing platform governance as an alternative process, which should more effectively contribute to China's circular economy. The study explores the feasibility of providing such a platform governance mode by using Petri net to compare the traditional governance process and platform governance process for the management of muck trucks, and by using Nanjing's muck smart supervision platform as a case study to assess the effectiveness of the platform governance mode. Results from Petri net simulation modeling reveal that the platform governance mode is more effective than the traditional mode, and from the case study it is found that the success of Nanjing's muck waste management can be attributed to the platform governance mode. The platform management approach can therefore contribute to the sustainability of muck waste governance, and is suitable as an integrated and effective management mode for current practices of muck waste management and resource recovery in China. The main finding from the study is that the platform governance mode significantly improves the efficiency of muck waste management as compared with the traditional governance mode and can therefore provide greater economic and environmental benefits as part of a circular economy.

A comparative LCA of external wall assemblies in context of Iranian market: considering embodied and operational energy through BIM application

Building envelopes have a critical role in the sustainability of the construction sector. The goals of the current research are assessing the environmental impacts of typical exterior wall assemblies and presenting the best Iranian market option through taking account of both embodied and operational energy. Autodesk Green Building Studio (GBS) is used to determine the operating loads of each wall. Simapro, a life cycle assessment software, is applied for managing data on environmental impacts. The derived results demonstrate that human health is the most severe damage category for all the analyzed walls. Also, the end-of-life stage's environmental impact is insignificant compared to the production and use stages. Reducing carbon emissions has the highest priority, such that replacing 1 m2 of masonry brick wall (the worst option) with prefabricated extruded polystyrene (XPS) drywall (the best option) can result in saving 1257.85 kgCO2eq. The operational phase of the studied walls has a wide range of environmental impacts. Prefabricated Knauf drywall as well as prefabricated XPS drywall consumes less energy for the operating phase mainly due to providing sufficient quantity of isolations that leads to the better total environmental performance. In conclusion, it should be noted that the thermal performance of building materials should be given more attention.

Evaluation of socio-economic-ecological environmental benefits of urban renewal projects based on the coupling coordination degree

The success of urban renewal projects is attributed to the synergistic development of economic, social, and environmental sustainability. However, people often seek unilateral economic benefits and ignore the coupling and coordination degree of economy-social ecological and environmental benefits. This paper attempts to evaluate the success and sustainability of urban renewal projects based on the coupling coordination degree (CCD) of economic-social-ecological benefits. Firstly, this study relies on a literature review and structural interviews to build a coupling indicator system of economic-social-ecological benefits of urban renewal projects and calculates the weight of evaluation indicators based on the entropy method. Taking 15 urban renewal projects in Guangzhou as objects, this research measures their CCD and explores the coupling relationship. The research results show that (1) among the 60 comprehensive benefit evaluation indicator elements of urban renewal projects, the indicator element with a larger weight is " Education support facilities," the economic benefit indicator element with greater weight is "Regional housing price of renewal areas," and the ecological benefit indicator element with a large weight is "Vitality, and health of the urban landscape, and the characteristics of meeting the needs of residents of all ages." (2) From the project dimension, the evaluation value of the social, economic, and ecological environment benefits of different reconstruction projects have certain differences. From the perspective of the regional dimension, the CCD of comprehensive benefits of urban renewal projects has obvious regional differences. The projects with a high CCD are mostly distributed in the most economically developed regions. The economic and social benefits of the renewal projects located in the economic core of the city center are usually higher, but their eco-environmental benefits are not necessarily the highest. (3) The government should innovate the reconstruction mode of diversified development, improve the public participation mechanism, and build an efficient urban renewal ecosystem. This study concludes that the government should introduce relevant urban renewal policies to provide a theoretical basis and guidance for enterprises to participate in urban renewal projects.

Life Cycle Assessments of Circular Economy in the Built Environment—A Scoping Review

The Circular Economy (CE) is gaining traction throughout all industries and nations globally. However, despite several attempts, no one-off solutions for assessing the benefits and pitfalls of CE have been established, and neither have any measures with which to determine decisions. In line with this general observation, the Built Environment (BE) is no different. A tendency is observed in which, for the assessment of the environmental impacts of CE, a Life Cycle Assessment (LCA) has been deemed suitable. This paper presents a scoping review, using the PRISMA statement extension for scoping reviews, documenting how LCA has been applied for assessment of CE in the BE. The review covers a broad scope of literature, scoping the landscape, and delimits it into publications where CE strategy has been defined explicitly and described as a CE investigation. Among the LCAs applied, the dominant system boundary choice is the attributional approach. The authors open the discussion on whether this is actually suitable for answering the questions posed in the CE paradigm. From the review, and the discussion, the conclusion suggests that there is no dominant procedure in applying LCA of CE in the BE, even despite commonly developed LCA standards for the BE. Few studies also present the consideration to reconsider the applied LCA, as CE puts new questions (and thereby a potentially greater system boundary, as CE may imply greater societal consequences) that do not necessarily fit into the linear LCA framework currently applied in the BE.