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Normalization is applied to calculate the magnitude of an impact relative to the total impact of a given reference in Life Cycle Assessment (LCA). Normalized profiles of environmental impacts depend on geographical areas due to differences in the industrial and economic activities. So far, Normalization factors for China are not developed to conduct life cycle assessment analysis. The purpose of this research is to propose a database of normalization factors (NFs) covering 18 environmental impact categories in a Chinese context to fill the research gap. To establish the local database, we collected the domestic inventory of emission and resources extraction in China with necessary data extrapolation and then calculated the normalization factors based on the international model ReCiPe2016. Furthermore, normalization factors for each impact category are differentiated into individual and national levels, and the substance contribution proportion of the 18 environmental impact categories is quantified. In addition, we used the Data Quality Indicator (DQI) model to evaluate the data source of impact categories, while analyzing the uncertainty of normalization factors quantitatively based on the evaluation result. The results of the quantitative analyses showed uncertainty intervals for the normalization factors. It was found that ionizing radiation and toxicity got the largest uncertainty intervals among the normalization factors for all impact categories, owing to the low completeness of the inventory of substances in those two impact categories. According to the data quality indicators of impact categories, we located the data gap in domestic inventory and proposed measures to promote comprehensiveness of inventory. This China Normalization Factors Database provides the LCA researchers with a starting point for a subsequent weighing step and improves the accuracy of LCA study at the Chinese territory. • The domestic inventory of emission and resources extraction in China is collected. • A normalization factor database of LCA in China is established. • The characteristic pollutants identified in China are compared with those in the world. • A data quality matrix analysis of impact category is built for the uncertainty analysis. • Measures to diminish uncertainty are raised. [ABSTRACT FROM AUTHOR]

• Five methods are applied to explore the carbon benefit allocation in waste recycling. • Incentive effects of allocation methods were studied by sensitivity analysis. • Allocation method selection framework is proposed for waste recycling. • The study offers industry-specific insights for assessing recycling's carbon benefit. Recycling is crucial to address environmental issues caused by increasing wastes. Recycled materials can replace primary materials and offset greenhouse gas emissions, resulting in a carbon benefit. The environmental burdens and benefits of recycling cause broad discussions about the allocation of the burdens and benefits in life cycle assessment. The recycling situations and recyclability of different materials may be different, therefore, different allocation methods shall be selected. However, a common procedure for selecting the allocation method is missing, which led to difficulty in fairly and reasonably assessing the recycling benefits of wastes from the end-of-life product. In this work, we investigated the impact of carbon emissions in the end-of-life stage with a case of construction wastes. Five allocation methods were selected. A sensitivity analysis was conducted to identify factors influencing carbon benefit outcomes. Based on the case studies, we summarized the strengths and limitations of different allocation methods. Finally, a policy-oriented framework for selecting an allocation method was proposed. Our work serves as a basis for allocation method selection and also as a reference for quantifying the carbon benefit of recycled wastes. [ABSTRACT FROM AUTHOR]

Energy-intensive manufacturing is a major source of GHG emissions and environmental impacts. Countries in the world are all facing challenges in green manufacturing transformation. The conceptual evolution and actual implementation of green manufacturing in China and other countries show some similarities but also discrepancy. This paper describes the green manufacturing system in China from four aspects: green factory, green product, green park and green supply chain. The comparison of the four aspects is carried out between China and world's major economics including Europe, the United States, Japan, etc. Our results show that the common challenges among countries in the process of promoting green manufacturing are absent of corresponding product baseline standards in evaluating green products and no sufficient life cycle planning within plant boundaries. China is faced with specific challenges that there is no clear green product evaluation standards in life cycle assessment methods, system boundaries and life cycle stages of products. Other countries such as Germany and the United States are faced with challenges that there is a lack of environmental and performance evaluation as well as concrete implementation of life cycle evaluation within the factory boundary, and that there is difficulty for the national manufacturing industry chain to achieve a closed loop since industrial migration. We suggest that China draw lessons from the European Union, the United States and Japan in the elaborate methods design of green products assessment. As such, China's green factory assessment framework and strict government guidance can be a reference for other countries. [ABSTRACT FROM AUTHOR]

• Combining LCA and MOO into the solar photovoltaic planning at regional level. • Electricity supply cost of photovoltaic is inversely related to environmental impact. • The monocrystalline silicon technology can be given priority in photovoltaic regional planning. • A collaborative optimization model of environment and economy of renewable energy is proposed. • Uncertainties should be considered in photovoltaic regional planning. Solar power is a crucial force in renewable energy. The production of solar photovoltaic (PV) has nonnegligible effects on the environment, and the economic properties of various PV technologies range. Life Cycle Assessment (LCA) and Multi-objective Optimization (MOO) methodologies were utilized in this research to establish an optimization model of PV technology regional planning that took into account combined environmental impacts and Electricity Supply Cost (ESC). Through NSGA-II genetic algorithm, the Pareto optimal solution with the minimum environmental pollution and the lowest economic cost in the whole life cycle of solar PV technology is obtained. The results demonstrated that toxic environmental impacts are the primary categories of crystalline silicon PV panels' potential environmental impacts, and monocrystalline silicon PV technology is the more advantageous choice when considering environmental impact and ESC. Results of sensitivity analysis indicated that uncertain factors would affect the scheme selection. This research offers a planning methodology for regional sustainable development of solar PV technology considering both environmental and economic objectives. [ABSTRACT FROM AUTHOR]

With the rapid development of the construction industry in China, a large number of building materials have been consumed and resulted in huge pressure to the resources and environment. Based on localized construction material inventory data, China-specific characterization factors in LIME-3 (Life Cycle Impact Assessment based on Endpoint Modeling) was used to evaluate the environmental impact of human health. It is found that ceramic tiles and steel have high burden of human health impact, which are 2.98E-05 DALY and 1.72E-05 DALY, respectively, while gravel and natural sand have relatively low impact, which are 5.12E-08 DALY and 4.30E-09 DALY, respectively. Among the five midpoint impact categories (climate change, air pollution, photochemical oxidant formation, water consumption and human toxicity) that have effects on "human health", the contribution proportion of different building materials vary significantly. The environmental impact assessment results of different building materials on "human health" under LIME-3 and ReCiPe were compared. Results show that the burden of human health impact for ceramic tile under LIME-3 is nearly 67 times that under ReCiPe, which is mainly due to the different proportion of human toxicity in the endpoint of human health and the difference between the two methods in material characterization factors. For high impact burden materials such as steel and ceramic tiles, impact mitigation strategies have been proposed, such as applying electric arc furnace steel making to improve the productivity of steel and the recycling rate of scrap steel, and promoting new dry powder production processes to reduce alkanes and fluorides emission. This study considered an additional midpoint impact category (human toxicity) based on the LIME-3, directing the impact assessment against indicators located at the end of the impact pathway, such as human health. A database of characterization factors of human toxicity for dozens of substances or components has been constructed. Efforts were made in the direction of developing the application of the most widely used impact assessment methods. [Display omitted] • Ceramic tiles and steel have high burden of human health impact based on China-specific characterization factors in LIME-3. • Human health impact for ceramic tile under LIME-3 are much higher than the results under ReCiPe. • More midpoint impact categories such as human toxicity should be considered in LIME. [ABSTRACT FROM AUTHOR]

• Current and emerging urban mining technologies are identified. • LCA and LCCA results on construction and demolition waste management are reviewed. • Modeling of the potentials and costs of urban mining technologies is evaluated. • Opportunities to improve LCA and LCCA in C&DW decision-making are discussed. Knowledge gained from anthropogenic resource prospecting can shed light on the theoretical potential of secondary resources stored in anthropogenic systems. Among others, secondary resources accumulated in the built environment account for a big fraction of anthropogenic resources, indicating great potential for urban mining. However, realizing these opportunities and developing urban mining strategies will require a comprehensive understanding of the technical viability of urban mining technologies, and how their implementation will affect the technical, economic, and environmental performance of a construction and demolition waste (C&DW) management system. To address these important issues, this review summarizes (1) current and emerging technologies that can enable the transition from anthropogenic resource prospecting to anthropogenic resource mining, (2) Life Cycle Assessment (LCA) and Life Cycle Cost Analysis (LCCA) results to date on various C&DW management systems, (3) key parameters that govern the technical, economic, and environmental performance of a C&DW management system, and (4) opportunities for improving the methodology of LCAs and LCCAs for future C&DW management. We find that enhancing the utility of extant LCAs and LCCAs in guiding technology deployment and policy decisions can be achieved by considering key parameters governing the techno-economic and environmental performance of C&DW management. In addition, it is critical to adopt and upscale emerging technologies to increase the added value of materials or products recovered from C&DW. [ABSTRACT FROM AUTHOR]