Trân trọng giới thiệu tới quý độc giả Công bố quốc tế lĩnh vực môi trường số 36-2022. Đặc biệt, trong số này có nghiên cứu “Giá dầu diesel cao hơn đi kèm với mức độ ô nhiễm thấp hơn: Bằng chứng từ Việt Nam”.
Về quản lý môi trường
– Vượt qua những thách thức do lượng lớn chất thải y sinh tạo ra trong đại dịch COVID-19.
– Số liệu thống nhất về chất thải: Một công cụ được đánh giá cao trong lập kế hoạch chiến lược.
– Trí tuệ nhân tạo ảnh hưởng như thế nào đến tăng trưởng kinh tế xanh? – Niềm tin từ Trung Quốc.
– Xây dựng các kịch bản phát thải hóa chất sử dụng Con đường kinh tế xã hội.
– Thay thế năng lượng tái tạo và tác động của công nghệ năng lượng trong nền kinh tế chuyển đổi: Góc nhìn từ Pakistan.
– Giá dầu diesel cao hơn đi kèm với mức độ ô nhiễm thấp hơn: Bằng chứng từ Việt Nam.
– Rào cản đối với quản lý chất thải hữu cơ trong nền kinh tế tuần hoàn.
– Các điểm chính về quản lý xanh đối với nước-năng lượng-thực phẩm trong Sáng kiến Vành đai và Con đường: Hiệu quả sử dụng tài nguyên, hành vi nhu cầu cuối cùng và bất bình đẳng thương mại.
– Thái độ ủng hộ môi trường, điều kiện môi trường địa phương và hành vi tái chế.
Về môi trường đô thị
– Tối ưu hóa mạng lưới cơ sở hạ tầng xanh dựa trên khả năng tích hợp mái xanh trong một khu đô thị mật độ cao – Một nghiên cứu điển hình của Bắc Kinh, Trung Quốc.
– Sự thay đổi về mặt không gian và loại bỏ các hóa chất gây rối loạn nội tiết được lựa chọn trong các nhà máy xử lý nước thải trên khắp Trung Quốc: So sánh quy trình xử lý.
– Tiếp xúc trong nhà với các chất chống cháy được chọn và đánh giá tầm quan trọng của các thông số môi trường, hành vi con người và sinh lý.
– Sử dụng giám sát nước thải để phát hiện sớm các biến thể Alpha và Epsilon SARS-CoV-2 cần quan tâm và ước tính gánh nặng lây nhiễm COVID-19 tổng thể.
– Đánh giá chất lượng không khí trong môi trường trong nhà và ngoài trời: Tác động của các biện pháp chống COVID-19.
– Phát triển và đánh giá kiểm kê các chất ô nhiễm không khí làm xấu chất lượng không khí ở siêu đô thị Ấn Độ Bengaluru.
– PAHs và nitro-PAHs ở đô thị Bắc Kinh từ năm 2017 đến 2018: Đặc điểm, nguồn, cơ chế chuyển đổi và đánh giá rủi ro.
– Tác động của quá trình lắng sơ cấp đến hiệu suất tạo hạt và xử lý nước thải đô thị bằng quy trình bùn hạt hiếu khí.
Về môi trường khu công nghiệp
– Mô hình tính toán CO2 và phân tích giảm thiểu cacbon của các nhà máy gang thép dựa trên chuyển hóa cacbon trong và giữa các quá trình.
– Xử lý nước thải công nghiệp giấy bằng đông tụ điện và khía cạnh quản lý bùn.
– Đóng góp vào sản xuất sạch hơn theo quan điểm giảm thiểu phát thải VOC: Đánh giá.
– Hiểu biết sâu sắc về các công nghệ vật lý, hóa học và công nghệ kết hợp hiện tại được sử dụng để xử lý nước thải bị ô nhiễm dược phẩm.
– Phân tích các thông số quá trình về sử dụng năng lượng và tác động đến môi trường của luyện kim hydro.
– Theo đuổi tính bền vững tích cực thuần cho quá trình khử cacbon trong công nghiệp với các hệ thống năng lượng lai.
– Hydro xanh và các sản phẩm cơ bản công nghiệp: Tương lai của các nhà xuất khẩu nhiên liệu hóa thạch trong một thế giới không có ròng.
– Nền kinh tế chính trị của việc tích cực loại bỏ các ngành công nghiệp có hại: Bài học từ các ngành dựa vào tài nguyên ngoài nhiên liệu hóa thạch.
– Nâng cao hiệu quả sử dụng năng lượng của các ngành công nghiệp Ấn Độ: Hiệu quả của chương trình PAT.
Xin trân trọng giới thiệu!
QUẢN LÝ MÔI TRƯỜNG
1. Variations of COVID-19 mortality are affected by economic disparities across countries
Science of The Total Environment, Volume 832, 1 August 2022, 154770
Abstract
Background
When the COVID-19 case number reaches a maximum in a country, its capacity and management of health system face greatest challenge.
Methods
We performed a cross-sectional study on data of turning points for cases and deaths for the first three waves of COVID-19 in countries with more than 5000 cumulative cases, as reported by Worldometers and WHO Coronavirus (COVID-19) Dashboard. We compared the case fatality rates (CFRs) and time lags (in unit of day) between the turning points of cases and deaths among countries in different development stages and potential influence factors.
As of May 10, 2021, 106 out of 222 countries or regions (56%) reported more than 5000 cases. Approximately half of them have experienced all the three waves of COVID-19 disease. The average mortality rate at the disease turning point was 0.038 for the first wave, 0.020 for the second wave, and 0.023 for wave 3. In high-income countries, the mortality rates during the first wave are higher than that of the other income levels. However, the mortality rates during the second and third waves of COVID-19 were much lower than those of the first wave, with a significant reduction from 5.7% to 1.7% approximately 70%. At the same time, high-income countries exhibited a 2-fold increase in time lags during the second and the third waves compared to the first wave, suggesting that the periods between the cases and deaths turning point extended. High rates in the first wave in developed countries are associated to multiple factors including transportation, population density, and aging populations. In upper middle- and lower middle-income countries, the decreasing of mortality rates in the second and third waves were subtle or even reversed, with increased mortality during the following waves. In the upper and lower middle-income countries, the time lags were about 50% of the durations observed from high-income countries.
Interpretation
Economy and medical resources affect the efficiency of COVID-19 mitigation and the clinical outcomes of the patients. The situation is likely to become even worse in the light of these countries’ limited ability to combat COVID-19 and prevent severe outcomes or deaths as the new variant transmission becomes dominant.
2. Overcoming challenges due to enhanced biomedical waste generation during COVID-19 pandemic
Science of The Total Environment, Volume 832, 1 August 2022, 155072
Abstract
Biomedical wastes (BMWs) are potentially infectious to the environment and health. They are co-dependent and accumulative during the ongoing coronavirus disease-2019(COVID-19) pandemic. In India the standard treatment processes of BMWs are incineration, autoclaving, shredding, and deep burial; however, incineration and autoclaving are the leading techniques applied by many treatment providers. These conventional treatment methods have several drawbacks in terms of energy, cost, and emission. But the actual problem for the treatment providers is the huge and non-uniform flow of the BMWs during the pandemic. The existing treatment methods are lacking flexibility for the non-uniform flow. The Government of India has provisionally approved some new techniques like plasma pyrolysis, sharp/needle blaster, and PIWS-3000 technologies on a trial basis. But they are all found to be inadequate in the pandemic. Therefore, there is an absolute requirement to micromanage the BMWs based on certain parameters for the possible COVID-19 like pandemic in the future. Segregation is a major step of the BMW management. Its guideline may be shuffled as segregation at the entry points followed by collection instead of the existing system of the collection followed by segregation. Other steps like transportation, location of treatment facilities, upgradation of the existing treatment facilities, and new technologies can solve the challenges up to a certain extent. Technologies like microwave treatment, alkaline hydrolysis, steam sterilization, biological treatment, catalytic solar disinfection, and nanotechnology have a lot of scopes for the treatment of BMWs. Hi-tech approaches in handling and transportation are found to be fruitful in the initial steps of BMW management. End products of the treated BMWs can be potentially fabricated for the application in the built environment. Some policies need to be re-evaluated by the health care facilities or government administrations for efficient BMW management.
3. Decade-long trends in chemical component properties of PM2.5 in Beijing, China (2011-2020)
Science of The Total Environment, Volume 832, 1 August 2022, 154664
Abstract
A 10-year-long measurement of water-soluble inorganic ions in PM2.5 was made in Beijing from June 2011 to December 2020, to investigate the interannual trends of chemical characteristics of PM2.5 and to provide insights into the future prevention and control of PM2.5 pollution. From 2011 to 2020, with the implementation of strict air pollution control strategies, significant changes of PM2.5 have been observed in Beijing, with NO3−, SO42− and NH4+ decreasing at rates of 5.10, 8.80 and 7.64% yr−1 respectively. The percentages of NO3− and SO42− under elevated pollution levels were investigated. When PM2.5 values fell in the range of 0–400 μg m−3, NO3−/ SO42− values were mostly higher than 1 and showed upward trends from 2011 to 2020. However, under extremely heavy haze conditions, SO42− dominated PM2.5 formation. This result was closely related to the change characteristics of the oxidation ratio of sulfate (SOR), the oxidation ratio of nitrate (NOR) and gaseous precursors under different pollution levels. The change characteristics of NOR and SOR under elevated PM2.5 levels indicated that the aqueous phase oxidation was the key process driving SO42− formation; while as for NO3−, in addition to the availability of NH4+, the atmospheric oxidation capacity made crucial roles. The analysis of typical haze episodes during the past decade indicated that the emission reduction of gaseous pollutants, especially SO2, made great contributions to the improved PM2.5 air quality in Beijing. We highlighted that future efforts should focus on enhanced reduction of NO2 emission and control of atmospheric oxidation capacity to further reduce particulate nitrate formation.
4. Unified waste metrics: A gamified tool in next-generation strategic planning
Science of The Total Environment, Volume 833, 10 August 2022, 154835
Abstract
A gamification approach for tackling waste management planning and urban development provide a more engaging and interactive experience with high pedagogical potential. Existing serious games involving waste management are complex in their data ingestion, use, and presentation, limiting individuals’ opportunities to gain knowledge and decision-making skills transferrable to the real world. Simulations, by comparison, provide either an oversimplified and unrealistic user interface or explore in depth individual rather than aggregate key performance indicators for waste management, limiting potential knowledge retention. There is a clear opportunity in creating an informative, easy-to-use simulation-based game to help stakeholders build understanding of waste management policies, performance, and causal relationships. This gamified tool provides clear feedback through quick-visibility performance indicators (i.e., waste accumulation index, waste compositional analysis, prevention activities etc.) and offers the opportunity, through multi-criteria decision making, of simulating real-life scenarios and previewing the possible outcomes of certain in-game actions. The research question is how the process of gamification might serve as powerful tool for educating decision makers. The results are considered as a reference point to any policy maker intending to assess environmental performance, proposed activities to reach Circular Economy targets, and European Green Deal and UN Sustainable Development Goals.
5. How does artificial intelligence affect green economic growth? – Evidence from China
Science of The Total Environment, Volume 834, 15 August 2022, 155306
Abstract
As the driving force behind the new wave of technological advancement, artificial intelligence (AI) paves the way for a new era of green economic growth. This paper uses the case of China and constructs a relevant mathematical model to propose the two-way impact of AI on green total factor productivity (GTFP) and systematically analyze the impact of AI on green economic growth. The main findings of this study are that AI has a significant “U-shaped” effect on GTFP, which was estimated using a nonlinear dynamic panel regression model. The analysis of regional heterogeneity shows that improving AI in resource-rich areas can boost GTFP and break the “resource curse”. The “productivity paradox” arises, according to the industry heterogeneity analysis, because the current low level of intelligence in resource-intensive and labor-intensive industries fails to improve GTFP. This paper also breaks down GTFP into green technological progress and green efficiency improvement effects to figure out how AI affects green economic growth.
6. Development of chemical emission scenarios using the Shared Socio-economic Pathways
Science of The Total Environment, Volume 836, 25 August 2022, 155530
Abstract
The widespread use of chemicals has led to significant water quality concerns, and their use is still increasing. Hence, there is an urgent need to understand the possible future trends in chemical emissions to water systems. This paper proposes a general framework for developing emission scenarios for chemicals to water using the Shared Socio-economic Pathways (SSPs) based on an emission-factor approach. The proposed approach involves three steps: (i) identification of the main drivers of emissions, (ii) quantification of emission factors based on analysis of publicly available data, and (iii) projection of emissions based on projected changes in the drivers and emission factors. The approach was tested in Europe for five chemical groups and on a national scale for five specific chemicals representing pharmaceuticals, pesticides, and industrial chemicals. The resulting emission scenarios show widely diverging trends of increased emissions by 240% for ibuprofen in SSP3 (regional rivalry) to a 68% decrease for diclofenac in SSP1 (sustainable development) by 2050. While emissions typically decrease in SSP1, they follow the historical trend in SSP2 (middle-of-the-road scenario) and show an increase in the regional rivalry scenario SSP3 for most selected chemicals. Overall, the framework allows understanding of future chemical emissions trends as a function of the socio-economic trends as captured in the SSPs. Our scenarios for chemical emissions can thus be used to model future aqueous emissions to support risk assessment. While the framework can be easily extended to other pharmaceuticals and pesticides, it heavily leans on the availability and quality of historical emission data and a detailed understanding of emission sources for industrial chemicals.
7. Renewable energy substitution and energy technology impact in a transitional economy: A perspective from Pakistan
Journal of Cleaner Production, Volume 360, 1 August 2022, 132163
Abstract
Almost 87.8% use of fossil fuel in its mixed energy, with only 12.1% coming from electricity, which has taken submerge environmental risk from CO2 emissions (CO2Es). Like many countries, Pakistan has set ambitious goals for a feasible transition towards clean energy sources. In this study, a trans-log production function is adopted to investigate the energy substitution possibility and then estimate the emissions reduction potential that comes through such a conversion. The results show that: (i) all the output elasticities and substitution elasticities contribute to economic development. The research leads towards evidence of efficiency for renewable electricity to add significantly to Pakistan’s productivity. Though, it has the prospective to add a 5% growth-share if the capital investment is at least twice beyond present levels. (ii) Based on technological progress, energy substitutability, economy, and inter-fuel substitution are possible. Also, inter-fuel substitutability is limited in exercise because of the heavy costs linked to cleaner energy generation technologies. Moreover, two investment scenarios evidence marginal falls in non-clean energy (between 0.203 and 0.213%) and CO2Es when energy substitutability is conducted. Generally, existing outcomes have insinuations about Pakistan’s economic progress, renewable development, and carbon emissions.
8. A complete total-factor CO2 emissions efficiency measure and “2030•60 CO2 emissions targets” for Shandong Province, China
Journal of Cleaner Production, Volume 360, 1 August 2022, 132230
Abstract
Improving efficiencies in CO2 emissions plays an important role in achieving carbon neutrality, but often overlooked in the planning and transformation of energy systems. Although data envelopment analysis (DEA) models are widely used for measuring efficiency, few papers have paid attention to whether the selected variables properly reflect the process of real-life production. This paper presents improvements to the existing input-output variable system of total-factor CO2 emissions efficiency (TFCEE). The underlying research uses a slacks-based measure (SBM) with undesirable outputs to evaluate industrial TFCEE in Shandong Province, China, during the period 2006–2017. Based on current potential for CO2 emissions abatement, a roadmap is proposed for the “2030•60 targets”. We ascertained that the main engine of net zero CO2 emissions is efficiency improvement initially, shifting to structural adjustment by 2035. By 2037, carbon capture, utilization, and storage (CCUS) technologies are expected to be the second largest emission reducer, following structural adjustment. Based on a correct variable selection for CO2 emissions efficiency measurement and the exploration of a carbon emission reduction roadmap, this study provides both empirical evidence and policy implications for achieving carbon peak and carbon neutral targets in industrially developed regions such as Shandong Province.
9. Higher diesel price is associated with lower level of pollution: Evidence from Vietnam
Journal of Cleaner Production, Volume 361, 10 August 2022, 132245
Abstract
Controlling and reducing PM2.5 levels are essential, but among many studies on this topic only a few have focused on assessing the effectiveness of air pollution control policies through fuel prices. This study aims to investigate the association between higher fuel prices and PM2.5 concentrations in Vietnam. Daily data on PM2.5 in the two largest cities of Vietnam (Hanoi and Ho Chi Minh City) and prices of different fuels were collected for two years (2016–2017). A linear regression model was performed to evaluate the association between PM2.5 and fuel prices, including lag effects for up to ten days. The long term and seasonal effects on PM2.5 were controlled using a natural cubic spline function of time with three degrees of freedom per year. For every 1,000 VND increase in the price of diesel, there was a decrease of 2.7% (95% CI: −8.0, 2.7) and 13.4% (95%CI: −22.3, −4.5) in PM2.5 in Ho Chi Minh City and Hanoi, respectively. On the contrary, there was no statistically significant association between gasoline prices (both RON-95 and RON-92) and PM2.5 in both Ho Chi Minh City and Hanoi. These findings provided evidence that changes in the price of the more polluting fuel (diesel) could significantly impact the level of PM2.5 in the large cities of Vietnam. Our study offers valuable perspectives for policymakers to formulate environmental policies regarding different fuel excises.
10. Achieving China’s carbon neutrality: Predicting driving factors of CO2 emission by artificial neural network
Journal of Cleaner Production, Volume 362, 15 August 2022, 132331
Abstract
After China announced its commitment to peak carbon emissions by 2030 and carbon neutrality around 2060, concerns arose over its CO2 emission paths. The feasibility of net-zero emission in China has been assessed, yet how emission-driving factors may behave throughout different paths remains explored. Based on the Logarithmic Mean Divisia Index decomposition model, the present study examined the driving factors from 2005 to 2016 and applied the artificial neural network for factor prediction from 2016 to 2060. Energy efficiency plays a vital role in reducing CO2 emissions by 4.90 Gigatons (Gt), while economic growth, as the decisive promoting factor, encourages emissions by 8.58 Gt. In the pre-peak phase 2016–2030, energy intensity is the leading emission counterforce decreasing CO2 emissions by up to a maximum of 11.3 Gt before sliding to the second position after 2030. During the period of 2030–2060, industrial structure exerts a significant negative effect eliminating up to 6.78–6.87 Gt of CO2 emissions, meanwhile showing an accelerated increase (0.167–0.172 Gt/yr in 2030–2050, and 0.333–0.352 Gt/yr in 2050–2060). From an economic perspective, negative emission technology shows little advantage before 2030, but thereafter offers a lower-cost emission reduction until 2060. Sustainable scenarios’ cumulative emissions are totally 420.1–506.3 Gt CO2 between 2005 and 2060, with emission peaks at 9.46–11.58 Gt around 2030. Carbon sinks & carbon capture and storage (CCS) and BECCS (biomass energy and CCS) are preferable for China to accomplish carbon neutrality, contributing 1.33–5.09 Gt CO2 in 2060. Projection of CO2 emission drivers could highlight the sensitive variables during emission mitigation and neutralization, and benefit global green development.
11. Barriers to organic waste management in a circular economy
Journal of Cleaner Production, Volume 362, 15 August 2022, 132282
Abstract
Organic waste disposal methods, notably landfilling, not only deplete resources but also contribute to environmental challenges. This research looks at potential barriers to organic waste management solutions. The objective of this study is to identify the barriers to organic waste management solutions from an actor’s perspective, and to explore their causal relationships to overcome the organic waste management problem from a system perspective. Several key challenges were identified regarding organic waste management solution, the current intervention overview indicates that promoting and tracking attention towards “value to waste” would be an effective solution approach. Waste collection fees, unethical behavior, and a lack of engagement and commitment in activities show a subsequent effect on consumer-household solutions, which are currently acting as priority barriers in this research. In order to have a better understanding of this complex issue, a detailed knowledge of barriers (leading to organic waste) is discovered and evaluated with the application of fuzzy Decision Making Trial and Evaluation Laboratory (DEMATEL). The data for this research has been taken in the context of a developing economy like India. This work can provide structural support to the managers by knowing the cause (influencing) and effect-group (influencing) barriers to the effective implementation of an organic waste management system in a circular economy context.
12. Key points for green management of water-energy-food in the Belt and Road Initiative: Resource utilization efficiency, final demand behaviors and trade inequalities
Journal of Cleaner Production, Volume 362, 15 August 2022, 132386
Abstract
As the largest contemporary platform for international cooperation, the Belt and Road Initiative (BRI) may carry the risk of increasing pressure on water, energy and food (WEF) resources while driving economic development. WEF nexus analyses can help promote green and sustainable management of the BRI’s resources, but has received little attention. Based on a multi-regional input-output model, this study identifies key points of WEF nexus management in the BRI from WEF utilization efficiency, final demand behavior and trade inequality. On the supply side, the common points of inefficiency in WEF use were primarily manufacturing and transport and communication in China and India, chemicals and manufacturing in Russia, and chemicals, manufacturing, and transport and communication in Iran. Water and food systems were closely linked through the planting industry. The focus for adjustment was the direct water and land use efficiency of the planting industry in India and Pakistan. On the final demand side, household consumption drove 73.6%, 50.0%, and 80.1% of WEF, respectively; particularly richer countries (e.g., South Korea and Italy) had more serious overconsumption problems. The macro-control points of investment behavior primarily include manufacturing, construction, and transport and communication in China, South Korea, Italy, and Russia. With the reduction of trade barriers, countries with a propensity to export, particularly those with resource scarcity, face trade-offs in export behavior (e.g., exports of crops, and food and tobacco from China, India and Pakistan). Notably, for certain resource-rich economies, such as Southeast Asia, Russia, and West Asia, improving the efficiency of relevant sectors, rather than restricting exports, is the priority. In bilateral trade, richer countries acquired both economic and resource advantages, whereas countries such as China, India, and Pakistan faced serious trade inequalities. Greener and more equitable WEF development in the BRI could be better promoted through strengthening dialogue and cooperation regarding supply and demand at these key points.
13. Pro-environmental attitudes, local environmental conditions and recycling behavior
Journal of Cleaner Production, Volume 362, 15 August 2022, 132399
Abstract
The paper uses Italian official survey data collected in 2012 from more than 20 thousand households to shed light on the determinants of people’s pro-environmental behavior, more specifically the differentiation of domestic waste disposal. A rich interdisciplinary literature has developed to explain why people may make eco-friendly choices, which come at a personal cost and provide benefits accruing largely to other people. The paper contributes to this investigation by jointly considering non-economic (a declared general interest in environmental issues), economic (easy access to recycling bins) and contextual (the perceived condition of the local environment) determinants of recycling. The results show that a higher general interest in environmental issues is associated with an increase in recycling of 7.5 percentage points, while easy access to facilities is associated with an increase in recycling of 5.3 percentage points. More educated households are also more inclined to behave pro-environmentally: a university degree or a Ph.D. is associated with an increase in the probability of recycling of 5.2 percentage points. Finally, the paper provides evidence that locally perceiving environmental degradation is associated with a 5.8 percentage points decrease in the likelihood of recycling. This last result may be explained by bounded rationality and/or conditional social cooperation, which both may lead to an environmental poverty trap. The final message is that the evidence gathered is difficult to reconcile with the “homo oeconomicus” hypothesis still prevailing in standard economic theory and that non-economic determinants have to be properly considered in the formulation of effective environmental policies.
14. Maximising the valorisation of organic waste locally available via carbon-to-nitrogen ratio Supply Composite Curve shifting
Journal of Cleaner Production, Volume 362, 15 August 2022, 132389
Abstract
Valorisation of organic waste can lead to cleaner production in the energy sector. One factor affecting the decision for organic waste valorisation to value-added products through biological processes is the carbon-to-nitrogen (C/N) ratio. All biological processes have preferential C/N ratios for optimum performance, while organic waste comes with a wide range of C/N ratios. The mismatch of the C/N ratio between the supply stream (organic waste) and the demand stream (biological process) can lead to suboptimal process performance and affect resource allocation. In this study, a new graphical C/N ratio Pinch Analysis approach was proposed by plotting cumulative carbon mass flowrate versus the cumulative nitrogen mass flowrate as x- and y-axes for the supply and demand sides. A series of graphical Supply Composite Curve (SCC) shifting, namely SCC right-shifting, SCC end-shifting, SCC detaching, and SCC down-shifting, were developed explicitly tackling different supply stream conditions in the hypothetical case studies while satisfying the demand streams with the aid of external supply. The external supply was determined by filling the gaps formed after the SCC was shifted to the right of the Demand Composite Curve (DCC). Specific heuristics were established to assess the range of C/N ratio for the external supply that is eligible and preferred to satisfy the demand streams. Stepwise procedures for mass flowrate allocation to mix the supply and match the demand were introduced. In this study, the demands for Case Study 1 were satisfied by 59.15% OWLA with 40.83% ES 3. For Case Study 2, the demands were satisfied by 76.19% OWLA with 23.81% ES 1. For Case Study 3, the demands were satisfied by 91.54% OWLA with 8.46% ES 1. The integration of the C/N ratio element in the Pinch-based Analysis of SCC shifting and exploring new optimisation scope can act as an advising tool for any individual, party, or organisation to optimally valorise the organic waste found within a local region.
15. Does national innovative city pilot policy promote green technology progress? Evidence from China
Journal of Cleaner Production, Volume 363, 20 August 2022, 132461
Abstract
The construction of national innovation systems has been receiving increasing attention. The present study aims to examine whether national innovative city pilot policy (NICP) influences green technology progress. Using a sample of 285 prefecture-level cities in China from 2003 to 2018, propensity score matching with difference-in-difference (PSM-DID) is used to empirically examine the effect of NICP on green technology progress. Our findings indicate that NICP can positively affect green technology progress. Green technology progress is promoted through NICP, specifically by innovation investment enhancement and innovation elements aggregation. Environmental regulation positively moderates the relation between NICP and green technology progress.
16. Have those countries declaring “zero carbon” or “carbon neutral” climate goals achieved carbon emissions-economic growth decoupling?
Journal of Cleaner Production, Volume 363, 20 August 2022, 132450
Abstract
Protecting the ecological environment is the common task of all mankind, and it is difficult for any country to achieve its goals alone. As matters stand, more than 130 countries and regions have proposed “zero carbon” or “carbon neutral” climate goals. This study established a three-stage carbon emission analysis framework for 29 countries that have proposed carbon neutrality targets. First, the carbon emissions of each country are decomposed based on Logarithmic Mean Divisia Index (LMDI) method. Then, the decoupling relationship between carbon emissions and economic development of each country is analyzed based on the Tapio model. Finally, according to the current and historical decoupling status, the future carbon emission trends of various countries are studied. The results indicated: (1) Energy intensity and economic growth are key drivers of carbon emissions. (2) There are certain differences in the decoupling status of countries during each period. Of which, the United States performed best, followed by the four countries whose climate goal process is in law (France, the United Kingdom, Hungary and New Zealand). (3) No matter in current decoupling state scenario or historical decoupling state scenario, the emission reduction effects of various countries are not satisfactory. Few countries can successfully achieve NDC targets or carbon neutral goals.
MÔI TRƯỜNG ĐÔ THỊ
1. Can the carbon metabolic activity of biofilm be regulated by the hydrodynamic conditions in urban rivers?
Science of The Total Environment, Volume 832, 1 August 2022, 155082
Abstract
Hydrodynamic regulation is widely used to improve the water quality of urban rivers. However, it is yet to explore substantially whether hydrodynamics could regulate the metabolic activity of biofilm in such aquatic systems. Herein, the pilot experiment of hydrodynamics in the rotation tanks was designed, including two experiment phases, namely constant flow and adjusting flow for 21 days and 14 days, respectively. In constant flow phase, biofilms grew in five shear stress gradients (R1–R5, 0.0044– 0.12 Pa). The carbon metabolic rate (k) of mature biofilms evaluated by BIOLOG ECO microplates showed a hump-shaped relationship with increasing shear stress, with R3 (0.049 Pa) the highest, while R5 (0.12 Pa) the lowest. To verify whether the metabolic activity of biofilm cultured at constant flow phase can be regulated by shear stress, we initiated the adjusting flow phase, and shear stress in reactors was reset uniformly at 0.049 Pa (with the highest k). Results showed the carbon metabolic activity of biofilm in reactor R4 and R5 increased rapidly by day 3, and there was no significant difference between the carbon metabolic rates among the five treatments by day 14. Meanwhile, the utilization levels of polymers and carbohydrates by biofilms were significantly different among the five treatments after hydrodynamic regulations. These results suggested that the total carbon metabolic activity of biofilm can be regulated by hydrodynamics, while the divergent changes of the specific carbon source category might affect the biofilm-mediated carbon biogeochemical processes, which should be considered for the application of hydrodynamic regulation in river ecological restoration projects.
2. Optimization of green infrastructure networks based on potential green roof integration in a high-density urban area – A case study of Beijing, China
Science of The Total Environment, Volume 834, 15 August 2022, 155307
Abstract
Green infrastructure network (GIN) optimization is an effective measure to reduce the landscape fragmentation caused by rapid urbanization. However, there are few targeted and practical studies of GINs in high-density urban areas with a prominent contradiction between ecological construction and land scarcity, leading to insufficient feasibility of most optimization paths as they avoid practical contradictions (scarcity of land, high cost, etc.). As an effective way to economically increase green infrastructure, green roofs have been demonstrated to provide habitats and stepping stones to increase landscape connectivity for high-mobility organisms. However, few studies have applied green roofs to GIN optimization. To address this question, a new approach to optimize GINs was proposed from the perspective of integrating potential green roofs (PGRs). A complete and feasible workflow was also established to rapidly, accurately, and cost-effectively extract PGRs, scientifically evaluate the comprehensive landscape connectivity accounting for PGR isolation factors, and practically optimize GINs according to the spatial differentiation of PGRs with high landscape connectivity. This was done by integrating high-spatial-resolution remote sensing, machine learning, morphological spatial pattern analysis, landscape index method, and a minimum cumulative resistance model. A case study in a typical high-density urban area within the Beijing Fifth Ring Road, China demonstrated the applicability and implications of the workflow. The results clearly showed that the study area had a high potential for green roof retrofitting, PGRs with high landscape connectivity could effectively improve the GINs, and the spatial differentiation characteristics of the PGR network optimization benefits provided the scientific guidance for developing targeted ecological strategies. The new approach effectively improves the scientificity and implementability of GINs. It also provides a strong reference for landscape planning and ecological construction in other high-density urban areas facing the contradiction between ecological construction and land scarcity.
3. Meteorological influences on daily variation and trend of summertime surface ozone over years of 2015 – 2020: Quantification for cities in the Yangtze River Delta
Science of The Total Environment, Volume 834, 15 August 2022, 155107
Abstract
We quantify the meteorological influences on daily variations and trends of maximum daily 8-h average ozone (MDA8 O3) concentrations by using multiple linear regression (MLR) and Lindeman, Merenda, and Gold (LMG) approaches. Different from previous region-based studies, we pay special attention to meteorological influences at city scale. Over 2015–2019, daily changes in key meteorological parameters could explain 47%–74% of the observed daily variations in summertime MDA8 O3 concentrations in Yangtze River Delta (YRD) and four cities (Shanghai, Nanjing, Hangzhou, and Hefei), with RH being the top driver. Over years of 2015–2020, daily concentrations of MDA8 O3 obtained from MLR equations (MDA8O3_MLR) of the local cities always had better performance than those of YRD. Compared with the observed daily MDA8 O3 in June–July–August (JJA) over the studied period, daily MDA8O3_MLR of the local cities (of YRD) had correlation coefficients of 0.73 (0.63), 0.75 (0.74), 0.79 (0.78), and 0.76 (0.73) in Shanghai, Nanjing, Hangzhou, and Hefei, respectively, and the MDA8O3_MLR of the local cities (of YRD) captured 54% (17%), 63% (51%), 52% (27%) of the observed O3-polluted days (days with MDA8 O3 concentration exceeding 160 μg m−3) in Shanghai, Nanjing, and Hangzhou, respectively. The meteorologically driven trends (Trend_Met) in MDA8 O3 were calculated using the established MLR equations. Over 2015–2019, the observed trends (Trend_Obs) and Trend_Met in MDA8 O3 were mostly positive in YRD, Nanjing, Hangzhou, and Hefei. In Shanghai, Trend_Obs, Trend_Met, and anthropogenically driven trend (estimated as Trend_Obs minus Trend_Met) of MDA8 O3 in JJA over 2015–2019 were −1.3, +1.0, and −2.3 μg m−3 y−1, respectively, indicating that the emission control measures alleviated O3 pollution in this city. Our results suggest that it is necessary to establish MLR equations at city scale to account for the role of meteorology in the actions of O3 pollution control.
4. Spatiotemporal variation and removal of selected endocrine-disrupting chemicals in wastewater treatment plants across China: Treatment process comparison
Science of The Total Environment, Volume 835, 20 August 2022, 155374
Abstract
In this study, the spatiotemporal variation in the occurrence of 19 endocrine-disrupting chemicals (EDCs) spanning four seasons in wastewater treatment plants (WWTPs) located in 17 Chinese cities was investigated. Removal efficiencies for selected EDCs in 17 WWTPs over four seasons were analyzed. Contributions of conventional and advanced process segments to the removal efficiency of EDCs were explored, which compared the removal efficacies of a variety of secondary and advanced processes for EDCs. Results showed that EDCs were extensively detected in WWTPs, with bisphenol A (BPA), dehydroepiandrosterone (DHRD), androstenedione (ADD), and pregnanediol (PD) being dominant in excess sludge and wastewater. Seasonally, the greatest seasonal differences were observed in the influent, with the concentrations of 12 EDCs varying significantly between seasons. Spatially, concentrations of BPA, DHRD, testosterone (TTR), and estriol (E3) in the influent significantly varied between the northern and southern WWTPs. Fourteen EDCs were removed steadily among the four seasons, while most EDCs had considerable removal differences between WWTPs. Contribution of the conventional process segment to the removal of individual EDCs was higher than that of the advanced process segment in WWTPs. Quantitative meta-analysis indicated that the anaerobic-anoxic-anaerobic (AAO) process in the various secondary processes had the highest removal of the target EDCs. Mass balance analysis further suggested that biodegradation in the aerobic tank of the AAO process was the major pathway for most EDCs removal. This study systematically depicts the spatiotemporal distribution of EDCs in WWTPs located across China and deepens the comprehension of EDCs removal in Chinese WWTPs from a treatment process perspective.
5. Indoor exposure to selected flame retardants and quantifying importance of environmental, human behavioral and physiological parameters
Science of The Total Environment, Volume 835, 20 August 2022, 155422
Abstract
Indoor exposure to organic flame retardants (FRs) has raised extensive concern due to associated adverse health effects. Indoor-exposure induced daily intakes of six widely used FRs individually ranged 0.002–611 ng/day and 0.02–463 ng/day, respectively, for adults and 2–6-year-old children; and resulting internal exposure levels ranged 0.1–159 and 2.1–4500 ng/g lipid, respectively. A proportion of 0.001–5.9% and 0.006–10.3% of individual FRs emitted into indoor air ultimately entered bodies of adults and children respectively. Tris(2-chloroisopropyl)phosphate dominated in emissions, whilst 2-ethylhexyl-2,3,4,5-tetrabromobenzoate dominated in human bodies. Hand-to-mouth contact was the most important exposure pathway for less volatile FRs including most brominated FRs, whilst inhalation was the predominant intake pathway of tris(2-chloroisopropyl)phosphate. Relative importance of 29 environmental, behavioral and physiological parameters was ranked to explore key drivers influencing exposure and accumulation of FRs in humans. Results suggested that frequent bathing and handwashing can reduce exposure effectively, especially for children. Bodyweight and lipid fraction were only positively related to internal accumulation and body-weight-normalized concentrations of compounds with low metabolic rates (half-lives ≥103 h) in humans. Our findings help control indoor exposure to FRs and are supportive of human exposome studies in the future.
6. Use of wastewater surveillance for early detection of Alpha and Epsilon SARS-CoV-2 variants of concern and estimation of overall COVID-19 infection burden
Science of The Total Environment, Volume 835, 20 August 2022, 155410
Abstract
A decline in diagnostic testing for SARS-CoV-2 is expected to delay the tracking of COVID-19 variants of concern and interest in the United States. We hypothesize that wastewater surveillance programs provide an effective alternative for detecting emerging variants and assessing COVID-19 incidence, particularly when clinical surveillance is limited. Here, we analyzed SARS-CoV-2 RNA in wastewater from eight locations across Southern Nevada between March 2020 and April 2021. Trends in SARS-CoV-2 RNA concentrations (ranging from 4.3 log10 gc/L to 8.7 log10 gc/L) matched trends in confirmed COVID-19 incidence, but wastewater surveillance also highlighted several limitations with the clinical data. Amplicon-based whole genome sequencing (WGS) of 86 wastewater samples identified the B.1.1.7 (Alpha) and B.1.429 (Epsilon) lineages in December 2020, but clinical sequencing failed to identify the variants until January 2021, thereby demonstrating that ‘pooled’ wastewater samples can sometimes expedite variant detection. Also, by calibrating fecal shedding (11.4 log10 gc/infection) and wastewater surveillance data to reported seroprevalence, we estimate that ~38% of individuals in Southern Nevada had been infected by SARS-CoV-2 as of April 2021, which is significantly higher than the 10% of individuals confirmed through clinical testing. Sewershed-specific ascertainment ratios (i.e., X-fold infection undercounts) ranged from 1.0 to 7.7, potentially due to demographic differences. Our data underscore the growing application of wastewater surveillance in not only the identification and quantification of infectious agents, but also the detection of variants of concern that may be missed when diagnostic testing is limited or unavailable.
7. Evaluation of air quality in indoor and outdoor environments: Impact of anti-COVID-19 measures
Science of The Total Environment, Volume 836, 25 August 2022, 155611
Abstract
This study monitors the presence of 88 volatile organic compounds (VOCs) and semi-volatile organic compounds (semi-VOCs) at the gas phase of seven indoor settings in a school in the city of Tarragona, Spain, and five outdoor locations around the city. The VOCs and semi-VOCs monitored were solvents (∑Solvents), aldehydes (∑Aldehydes), emerging organic compounds (∑EOCs), and other VOCs and semi-VOCs (∑Others). Passive sampling campaigns were performed using Carbopack X tubes followed by thermal desorption coupled to gas chromatography with mass spectrometry (TD-GC-MS). Overall, 70 of the target compounds included in the method were determined in the indoor air samples analysed, and 42 VOCs and semi-VOCs in the outdoor air samples. Our results showed that solvents were ubiquitous throughout the school at concentrations ranging from 272 μg m−3 to 423 μg m−3 and representing 68%–83% of total target compounds (∑Total). The values of ∑Total in 2021 were three times as high as those observed at the same indoor settings in 2019, with solvents experiencing the greatest increase. A plausible explanation for these observations is the implementation of anti-COVID-19 measures in the indoor settings, such as the intensification of cleaning activities and the use of hydroalcoholic gels as personal hygiene.
The ∑Total values observed in the indoor settings evaluated were twenty times higher than those found outdoors. ∑Solvents were the most representative compounds found indoors (74% of the ∑Total). The concentrations of VOCs and semi-VOCs observed in the outdoors were strictly related to combustion processes from automobile traffic and industrial activities, with ∑Others contributing 58%, ∑Solvents 31%, and ∑Aldehydes 11% of the ∑Total. EOCs, on the other hand, were not detected in any outdoor sample.
8. Methcathinone in wastewater: Drug of choice, or artefact?
Science of The Total Environment, Volume 836, 25 August 2022, 155696
Abstract
Methcathinone is a prevalent Novel Psychoactive Substance (NPS) used illicitly in some countries. Routine analysis of wastewater sampled from catchments in South Australia has shown a consistent low-level presence of the compound, inconsistent with NPS use. This raised the question was the occurrence due to regular use as a drug of choice or was it an artefact being produced from other sources in the sewer system? NPS consumption is generally sporadic and would therefore point to the origin of methcathinone in wastewater being due to in-sewer oxidation of its legal precursor, pseudoephedrine. The present study tested this hypothesis by comparing the levels of pseudoephedrine and methcathinone in wastewater samples collected bimonthly from 8 catchment sites in South Australia. Laboratory experiments exposing pseudoephedrine to common household oxidizing agents (hypochlorite and percarbonate) were also performed and the production of methcathinone was demonstrated and monitored. The results of this study showed that the level of pseudoephedrine and methcathinone measured in wastewater followed a similar pattern. However, there were periods when the levels of each compound diverged. Laboratory experiments showed that when exposed to various oxidizing agents, pseudoephedrine is oxidised to non-stoichiometric quantities of methcathinone. Although the use of methcathinone as a drug of choice remains possible, the results of this study indicate that the low and persistent level of methcathinone found in wastewater may arise in part from the oxidation of pseudoephedrine in the sewer system.
9. Spatiotemporal variations of PM2.5 pollution and its dynamic relationships with meteorological conditions in Beijing-Tianjin-Hebei region
Chemosphere, Volume 301, August 2022, 134640
Abstract
Identifying the effects of meteorological conditions on PM2.5 pollution is of great significance to explore methods to reduce atmospheric pollution. This study attempts to analyze the spatiotemporal variations of PM2.5 pollution and its dynamic nexus with meteorological factors in the Beijing-Tianjin-Hebei (BTH) region from 2015 to 2020 using standard deviation ellipse (SDE) and panel vector autoregressive (PVAR) model. The results indicate that: (1) In 2015–2020, PM2.5 pollution decreased significantly, indicating air pollution control policies in China have taken effect; Also, it showed a cumulative effect, or there was the path dependence of air pollution. (2) PM2.5 pollution presented a distribution pattern from northeast to southwest, while the directionality of air pollution has weakened. Based on SDE, PM2.5 pollution in Cangzhou can reflect the average level in the BTH; (3) Meteorological conditions exhibited a lagged and sustained effect on PM2.5 pollution. Specifically, the effects of meteorological factors on PM2.5 presented disequilibrium over time. In the long run, precipitation and temperature mainly showed negative impacts on PM2.5 pollution, while wind speed, relative humidity and sunshine duration aggravated PM2.5 pollution in the BTH. This study contributes to extending the study on the spatiotemporal evolution of PM2.5 pollution and its links with meteorological conditions.
10. Development and assessment of inventory of air pollutants that deteriorate the air quality in Indian megacity Bengaluru
Journal of Cleaner Production, Volume 360, 1 August 2022, 132209
Abstract
Air pollution in Indian megacities has been exceeding national and international standards. Indian megacity ‘Bengaluru’ is one amongst them where the identification of sources of air pollutants that contribute to the deterioration of air quality in cities and their spatio-temporal variability has become paramount importance. In this paper, we have made an attempt to develop a high resolution (∼0.4 km × ∼0.4 km) emission inventory of eight major pollutants for South-Asian megacity Bengaluru for 2020. The study quantifies the emission load from all possible sources in the city using megacity scenarios and bottom-up approach. The estimated annual emission for PM2.5, PM10, CO, NOx, SO2, VOC, BC and OC over Bengaluru are found to be 62.2 Gg/yr, 113.9 Gg/yr, 447.5 Gg/yr, 294.5 Gg/yr, 194.9 Gg/yr, 393.8 Gg/yr, 22.9 Gg/yr, and 36.5 Gg/yr respectively. The transport sector remains the dominating source of all pollutants. The unattended anthropogenic sources like windblown road dust, municipality solid waste burning are emerging sectors in the identified emission hotspots. Both traditionally dominating sectors like transport and industries play an acute role in the deteriorating air quality across the megacity. This developed new surface emission dataset will be a critical tool for air quality study and to frame pollution control strategies.
11. What factors affect household energy consumption in mega-cities? A case study of Guangzhou, China
Journal of Cleaner Production, Volume 363, 20 August 2022, 132388
Abstract
It is important for Chinese cities to advance sustainable energy consumption and ensure that they achieve their carbon emission peak and carbon neutrality. This paper develops a comprehensive assessment of the spatial variability and influencing factors of the quantity of household energy consumption per capita in mega-cities. Based on microlevel household survey data from Guangzhou, Guangdong Province, China (N = 1082), we analyze the spatial effects and factors of urban residents’ energy consumption. A spatial econometric model with four spatial weight matrices is employed, and the nested spatial weight matrix, which holds practical economic and geographical significance, is set. We find that (1) the quantity of energy consumption per capita of all households in Guangzhou is 189.57 kgce/year and shows a spatial difference, with 177.5 kgce/year in the central urban area and 203.47 kgce/year in the outskirts urban area. In particular, households in the outskirts of urban areas present a higher percentage of “high” and “medium-high” energy consumption per capita than those in central urban areas. (2) The quantity of household energy consumption per capita of urban residents is characterized by significant spatial correlation and agglomeration, with “high-high” and “low-low” agglomeration in central urban areas. (3) The household labor force, the housing area and household income are the core factors that drive the quantity of household energy consumption per capita, while the region and educational level are also main factors. We observe the diversity of the energy transition by comparing the patterns of the quantity of household energy consumption per capita within the city. A comprehensive picture of the diversity underlying the energy transition applied across cases can be distilled.
12. PAHs and nitro-PAHs in urban Beijing from 2017 to 2018: Characteristics, sources, transformation mechanism and risk assessment
Journal of Hazardous Materials, Volume 436, 15 August 2022, 129143
Abstract
Polycyclic aromatic hydrocarbons (PAHs) and their nitrated derivatives (NPAHs) attract continuous attention due to their distinct carcinogenicity and mutagenicity. To investigate the characteristics, sources, formation mechanism and health risk assessment of PAHs and NPAHs, PM2.5 were collected at an urban site in Beijing from 2017 to 2018. The highest PAHs and NPAHs concentrations were 77.92 ± 54.62 ng/m3 and 963.71 ± 695.06 pg/m3 in the winter campaign, which were several times larger than those in other seasonal campaigns. Distinct diurnal variations of nocturnal levels higher than daytime levels were shown for PAHs and NPAHs. Source analysis indicated that besides vehicle exhaust, biomass burning and coal combustion were important sources of PAHs and NPAHs in the fall and winter campaigns. Secondary formation in atmosphere was another source of NPAHs especially in the spring and summer campaigns. NO2 and RH could positively influence the heterogeneous formation of NPAHs when RH was less than 60%. Quantum calculation results confirmed the formation pathway of 2N‐FLA from the OH/NO3-initiated oxidation of FLA. The results of health risk assessment showed the potential health risks for the residents, especially in the winter campaign. These results indicated that PAHs and NPAHs still deserve attention following with the decrease concentrations of particulate matter.
13. Impact of primary sedimentation on granulation and treatment performance of municipal wastewater by aerobic granular sludge process
Journal of Environmental Management, Volume 315, 1 August 2022, 115191
Abstract
Aerobic granules contain microorganisms that are responsible for carbon, nitrogen, and phosphorus removal in aerobic granular sludge (AGS) process in which aerobic/anoxic/anaerobic layers (from surface to core) occur in a single granule. Optimizing the aerobic granular sludge (AGS) process for granulation and efficient nutrient removal can be challenging. The aim of this study was to examine the impact of settling prior to AGS process on granulation and treatment performance of the process. For this purpose, synthetic wastewater mimicking municipal wastewater was fed directly (Stage 1), and after primary sedimentation (Stage 2) to a laboratory-scale AGS system. In full-scale wastewater treatment plants, primary sedimentation is used to remove particulate organic matter and produce primary sludge which is sent to anaerobic digesters to produce biogas. Performances obtained in both stages were compared in terms of treatment efficiency, granule settling behavior, and granule morphology. Granulation was achieved in both stages with more than 92% chemical oxygen demand (COD) removal efficiencies in each stage. High nutrient removal was obtained in Stage 1 since anaerobic phase was long enough (i.e., 50 min) to hydrolyze particulate matter to become available for PAOs. Primary sedimentation caused a decrease in influent organic load and COD/N ratio, as a result, low nitrogen and phosphorus removal efficiencies were observed in Stage 2 compared to Stage 1. With this study, the effect of the primary sedimentation on the biological removal performance of AGS process was revealed. COD requirement for nutrient removal in AGS systems should be assessed by considering energy generation via biogas production from primary sedimentation sludge.
14. Urban and industrial environmental pollution control in China: An analysis of capital input, efficiency and influencing factors
Journal of Environmental Management, Volume 316, 15 August 2022, 115198
Abstract
With rapid urbanization and industrialization, environmental pollution caused by such activities has drawn much attention due to its adverse impacts on environmental quality and public health. Therefore, under the current background of China’s ecological civilization construction, promoting the precise and scientific treatment of environmental pollution holds great significance. This paper proposes an improved perpetual inventory method to systematically measure the capital stock of urban and industrial pollution control. The efficiency of urban and industrial pollution control is measured by adopting the global data envelopment analysis (DEA) model. Then, the influencing factors of pollution control efficiency are empirically analyzed by using the spatial Tobit regression model. The results reveal that, first, the growth rate of the capital input scale of urban pollution control is greater than that of industrial pollution control, and the spatial distribution of capital input is unbalanced. Second, the efficiency of urban and industrial pollution control from 1991 to 2019 was generally low. The current efficiency values of urban and industrial pollution control are less than 0.2 and 0.5, respectively, indicating that urban and industrial pollution control are far from efficient. Third, the efficiency of urban and industrial pollution control is significantly positively related to the level of urbanization and industrialization, has a U-shaped relationship with the economic development level, and has heterogeneous effects on technology, energy intensity, government influence and foreign trade. On this basis, we provide constructive suggestions for optimizing the performance of pollution control.
15. Information infrastructure and greenhouse gas emission performance in urban China: A difference-in-differences analysis
Journal of Environmental Management, Volume 316, 15 August 2022, 115252
Abstract
Owing to its network spillover effect, information infrastructure performs outstandingly in promoting economic growth and technological innovation, and has received widespread attention. However, the ecological performance of information infrastructure, especially its impact on greenhouse gas (GHG) emission performance, has been less studied. To investigate this issue, using panel data for 281 prefecture-level cities in China from 2003 to 2018, we treat the Broadband China policy as a quasi-natural experiment in information infrastructure, and conduct a difference-in-differences (DID) analysis. The results show that: (1) Information infrastructure significantly improves urban GHG emission performance. This conclusion holds even after controlling for pilot selection endogeneity, sampling bias, and other policy interference. (2) Technological innovation, industrial structure upgrading, factor allocation enhancement, and tertiary agglomeration are effective channels for information infrastructure to improve GHG emission performance. (3) The treatment effect varies with city size, digital economy level, and economic status. Specifically, information infrastructure exhibits significant emission reduction performance in cities with large size, advanced digital economy, and leading economic status, while the emission reduction effect drops in other cities. This study provides insights into the transition to a carbon-neutral manner for infrastructure in China and other developing countries.
MÔI TRƯỜNG KHU CÔNG NGHIỆP
1. Stabilization of arsenic and antimony Co-contaminated soil with an iron-based stabilizer: Assessment of strength, leaching and hydraulic properties and immobilization mechanisms
Chemosphere, Volume 301, August 2022, 134644
Abstract
Soils with relatively high concentrations of arsenic (As) and antimony (Sb) in mining areas would impose significant risks to human health and ecosystem. A new stabilizer PFSC composed of polymerized ferric sulfate (PFS) and calcium hydroxide (Ca(OH)2) is proposed to stabilize the soil with co-existed As and Sb sampled at an abandoned arsenic factory site. The effects of stabilizer dosage on the properties of the stabilized soil including leached concentrations of As and Sb, unconfined compressive strength (UCS), and hydraulic conductivity (kw) were investigated. The mechanisms of As and Sb immobilization in the soils were interpreted by Tessier’s sequential extraction procedure (SEP), scanning electron microscope (SEM), and X-ray diffraction (XRD) results.
The results showed increasing PFSC dosage was effective for reducing leached concentrations of As and Sb. When the PFSC dosage increased from 2% to 10%, the UCS and kw increased from 84 to 206 kPa and decreased from 6.48 × 10− 8 to 6.33 × 10− 9 m s − 1, respectively. Tessier’s SEP results showed that the leachable As and Sb fractions decreased from 12% to 5.6% and 7.5% to 3.8%, while the Fe–Mn oxides bound fractions increased from 22.3% to 29.4% and 13.2% to 19.5%. The SEM images and XRD patterns of untreated and PFSC stabilized contaminated soils indicated that hematite and calcite (CaCO3) were the main products of PFSC stabilization processes. Adsorption on ferrihydrite, entrapment in hematite lattices, and co-precipitate with calcite might were the main mechanisms of As and Sb immobilization.
2. Life cycle assessment and sustainable production evaluation of calcium carbide industry in China
Journal of Cleaner Production, Volume 360, 1 August 2022, 132176
Abstract
With the rapid development of the calcium carbide (CaC2) industry in China, the growth in CaC2 demand is confronting an increasing pressure to reduce environmental emissions. However, the environmental impacts of CaC2 production remain poorly understood. Life cycle assessment is employed in this study to provide a comprehensive analysis of the environmental performance of CaC2 production in China. The results show that the environmental load of the semi-closed furnace process is higher than that of the closed furnace process. Electricity supported by thermal power is the most sensitive factor. A significant regional layout of CaC2 production, adjoining the coal-electricity-intensive areas, has been observed in China. The sustainable scenarios are developed to evaluate the environmental reduction potential in terms of technical progress and electric grid improvement. It is noted that increasing the proportion of renewable power in the electric grid has obvious environmental benefits for CaC2 production. The average energy conservation and emission reduction index of CaC2 production in the northwest China is 1.81–2.10 times higher than that in the southwest China. The findings of this study will give a reference for the decision-makers to take conducive emission reduction measures for the sustainable development of the CaC2 industry in China.
3. CO2 accounting model and carbon reduction analysis of iron and steel plants based on intra- and inter-process carbon metabolism
Journal of Cleaner Production, Volume 360, 1 August 2022, 132190
Abstract
Carbon emission accounting for iron and steel plants (ISPs) is crucial to formulate prospective low-carbon strategies. In this study, a CO2 emission accounting model for an ISP that accounts both direct and indirect emissions is proposed. Especially, the proposed model considers the effect of the by-product gases of steel production on the intra- and inter-process carbon metabolism. For a comprehensive evaluation of the carbon emission level of an ISP, direct emissions are correspondingly categorized into process direct emissions (PDE) or combustion direct emissions (CDE), and as for indirect emissions, purchased electricity indirect emissions (EIE) and purchased coke indirect emissions (CIE) were considered. Subsequently, a case study is performed with the proposed model by calculating the CO2 emissions of an ISP using both the blast furnace-basic oxygen furnace (BF-BOF) and electric arc furnace (EAF) routes. The results show that the CO2 emissions of the ISP reach 1971.63 kg/t-cs, whereas the PDE of the BF process is 496.09 kg/t-cs, which is the bottleneck of carbon reduction. Furthermore, a top gas recycling-oxygen blast furnace (TGR-OBF) process-based integrated steelmaking process is built to analyse the possible carbon reduction potential. A comparison of the proposed TGR-OBF with traditional BF route reveals that a carbon reduction of 45.39% can be achieved with the TRG-OBF route. In addition, the effects of scrap rate and proportion of electricity generated from alternative energy on the carbon emissions of EAF is discussed. To reduce the EIE in ISPs, measures to optimise the power supplying structure should be considered. Scenario analysis indicates that by improving the efficiency of power generation of on-site power plants (OPPs) and increasing the application of waste energy recovery technology (WERT), EIE can be reduced by 44.49%.
4. Paper industry wastewater treatment by electrocoagulation and aspect of sludge management
Journal of Cleaner Production, Volume 360, 1 August 2022, 131970
Abstract
The paper production process comprises various manufacturing steps and generates an enormous amount of effluent, which consists of a large variety of contaminated chemicals. The higher color and chemical oxygen demand (COD) of the wastewater create a negative effect on all living forms and the natural environment. Electrocoagulation is a versatile process for the elimination of color and COD content from wastewater. In this study, the EC treatment has been used to identify the ideal conditions using several process variables such as pH, current density, time, and the dose of electrolyte. COD and color were reduced by up to 68% and 94%, respectively. Afterward, the treated water was compared with the standards of the world health organization (WHO) and the central pollution control board (CPCB) to find out the suitability of treated water for reuse for farming purposes. Germination tests of mung beans were conducted, and it was observed that the EC treated water is suitable for irrigation. The corrosion rate of mild steel was determined to be 2.85 mils/year, which has shown the short life span of mild steel electrodes. Furthermore, sludge produced by the EC process was analyzed and characterized for physicochemical analyses by using a variety of analytical techniques. The 69.93% iron content of the sludge was also recovered using the acid digestion method. After the physicochemical analyses, it was observed that sludge could also be utilized as a compelling supplement for plant growth, energy recovery, and industrial applications. According to this study, treated water could be a powerful alternative for reducing freshwater consumption in agricultural areas and increasing water availability in water-scarce areas.
5. Performance of ash from Amazonian biomasses as an alternative source of essential plant nutrients: An integrated and eco-friendly strategy for industrial waste management in the lack of raw fertilizer materials
Journal of Cleaner Production, Volume 360, 1 August 2022, 132222
Abstract
The increasing use of Amazonian biomass as a bioenergy source has contributed to the increased demand for fertilizers and the production of a large amount of ash. In addition to facing the challenges of an insufficient supply of agricultural inputs, the Amazon region has also faced problems in managing industrial wastes, which are not well characterized and for which few recycling options are available. Within this context, this study aimed to expand the knowledge regarding the use of Amazonian biomass ash, for which an integrative system between bioenergy and fertilizer production and waste management was proposed. This study evaluated ash applied as an alternative fertilizer, focusing on the availability and uptake of nutrients and heavy metals in acidic soils and the P dynamics using 31P-NMR. Three soils with different SOM values were treated with one of three doses of mineral fertilizer, namely, ash (35 Mg ha−1), phosphate fertilizer (2 Mg ha−1), or a mixture of ash and phosphate (35 and 2 Mg ha−1, respectively), and Avena sativa was grown to verify plant availability and the treatment effect on growth. The experiment was conducted for 60 d in a growth chamber. The ash application in pure form and mixed with phosphate slightly increased the pH (0.3–0.5 unit) and promoted significant increases in the availability of P (∼212%), Ca (∼165%), Mg (∼110%), and K (∼32%). In SOM-rich soils, the high microbial activity favored the transformation of inorganic P into organic P (2–21%), preventing fixation. The ash applications promoted positive effects on biomass production (∼62%) and increased the uptake of P (∼306%), Ca (∼181%), Mg (∼131%), and K (∼38%). Thus, Amazon biomass ash could be an alternative fertilizer source, representing a sustainable option for local socioeconomic development and the establishment of a circular economy system.
6. Research on the driving factors and carbon emission reduction pathways of China’s iron and steel industry under the vision of carbon neutrality”
Journal of Cleaner Production, Volume 360, 1 August 2022, 132238
Abstract
Under the vision of carbon neutrality, China’s iron and steel industry (CISI) urgently needs to achieve low-carbon development. To formulate effective and targeted emission reduction policies for CISI, the driving forces of carbon dioxide (CO2) emissions and future emission reduction pathways in CISI are explored in this paper. The Logarithmic Mean Divisia Index (LMDI) method and the Mean Impact Value (MIV) technique are adopted to analyze the driving factors of CO2 emissions in CISI at historical and prospective dimensions, respectively. Furthermore, the extreme learning machine (ELM) model optimized by the bat algorithm (BA) is established to project the carbon emission reduction pathways of CISI during 2020–2050 under the business-as-usual (BAU) scenario, the low-speed, medium-speed, and high-speed development scenarios considering the constraint of the carbon neutrality target. The results reveal that production capacity and energy efficiency are essential drivers of CO2 emissions in CISI. Consequently, aimed at achieving carbon neutrality, CISI should focus on eliminating backward capacity and simultaneously accelerating the deployment of advanced technologies. Additionally, it is difficult to accomplish the carbon neutrality goal by 2060 under the BAU scenario. Conversely, under the optimal emission reduction pathway determined by the high-speed development scenario, CISI will reach its peak in 2022 with a peak value of 2143.42 million tons of CO2 (MtCO2). The average annual emission abatement rate during 2022–2050 is maintained at approximately 4.47% and the cumulative reduction rate in 2050 will exceed 70% compared to the base year 2019. CISI is required to develop more stringent emission reduction measures to achieve significant emission abatement. The crude steel production capacity should be reduced to 533 Mt in 2050 and the capacity utilization rate should be maintained beyond 80%. The energy consumption per ton of steel must be decreased to 264 Kg of coal equivalent (Kgce) in 2050.
7. Contribution to cleaner production from the point of view of VOC emissions abatement: A review
Journal of Cleaner Production, Volume 361, 10 August 2022, 132112
Abstract
VOC (volatile organic compounds) belong to the group of undesirable air pollutants and their industrial emissions need to be treated before venting out into the atmosphere. From various advanced technologies for VOC mitigation, catalytic oxidation technology stands out as the modern and efficient method. This review presents the recent advances in the development and usage of novel catalysts for deep catalytic oxidation from the perspective of industrial feasibility. The goal is to efficiently contribute to cleaner production and provide cost-effective VOC emissions treatment by incorporating upscaled novel catalysts into VOC abatement technology. Different washcoats and active compound mixtures are developed and tested by many research groups worldwide. Extensive state-of-the-art of experimental data (129 data samples) on preferably noble metal-based catalysts and multi-metal oxides catalysts was carried out. The data are comprehensively summarized to identify generically optimal conditions to make efficient VOC abatement industrial gas catalyst with good conversions, long-term reliability, reasonable price and realistic possibilities for upscaling. Best reported T50 and T90 (temperatures corresponding to 50% and 90% conversions) for toluene were 110 °C and 144 °C, for ethanol 130 °C and 155 °C and for acetone 205 °C and 236 °C, respectively. The best performing catalysts surface areas were in the range of 16–103 m2 g−1. Furthermore, perspectives for the future development of novel VOC catalysts are provided. Particularly, the novel field of waste-to-catalysts and structured nanocatalyst development is explored. Lastly, the issues of upscaling to pilot and full-scale for each catalytic approach were discussed.
8. The status of corporate greenhouse gas emissions reporting in the food sector: An evaluation of food and beverage manufacturers
Journal of Cleaner Production, Volume 361, 10 August 2022, 132279
Abstract
The global food system is a key contributor to anthropogenic greenhouse gas emissions. Companies can play an important role in reducing these emissions but doing so effectively requires accurate emissions data. This study assessed the status and quality of corporate emissions reporting and target setting in the food system mainly through a survey of the public emission reports for 2018 to the CDP by the largest 50 food and beverage manufacturers worldwide.
In total, these companies reported 0.9 Gt CO2-eq. per year, although 7 companies did not publicly report emissions and many other companies provided incomplete reports of emissions. Direct emissions (Scope 1) comprised 8% of total reported emissions, and indirect emissions of purchased energy (Scope 2) 4% and of the value chain (Scope 3) 88%.
Despite the large proportion of Scope 3 emissions, reporting for this scope was often incomplete and inconsistent. For example, land-use change emissions are key for the food system but they are only explicitly covered by 10% of the companies. In addition, more than a third of reported Scope 3 emissions were not covered by emissions reduction targets of the companies. Based on a first order approximation, we estimated that the 50 companies are associated with 1.9–3.8 Gt CO2-eq. per year, indicating that between 53 and 77% of emissions go under-reported.
Together with the relatively poor reporting of Scope 3 emissions, our findings suggest that the food and beverages industry needs to urgently improve their GHG emissions reporting and management if they are serious about mitigating their impact on climate change. For more accurate emission reporting of companies in the food system, sector-specific guidance for Scope 3 is needed that prioritizes the most significant scope 3 categories, includes a dedicated category for emissions from land-use change and provides clear, easily applicable methods to determine the emissions from these high priority categories.
9. Insights into current physical, chemical and hybrid technologies used for the treatment of wastewater contaminated with pharmaceuticals
Journal of Cleaner Production, Volume 361, 10 August 2022, 132079
Abstract
The purpose of this article is to review the current physical, chemical and hybrid technologies practices employed in the removal of pharmaceuticals from liquid effluents originating from various resources including municipal waste, hospitals discharge with a focus on pharmaceutical manufacturing industry. Pharmaceutical pollutants are mostly persistent organic compounds that are not easily removed by conventional wastewater treatment processes. The literature reviewed shows that advanced oxidation processes are able to degrade these persistent pharmaceuticals. However, the oxidation may also introduce toxic oxidation intermediates/by-products if these processes are not properly monitored and operated. Physical treatments, like carbon adsorption and membrane filtration, can provide a barrier that prevents both parent compounds and toxic intermediates passing into treated wastewater. However, these processes are phase changing technologies in which contaminants are transferred from one phase to another hence, the retentate water and absorbent require further treatment, and properly managed disposal. The combination of different processes can be an ideal treatment scheme, for the retention and degradation of both parent and transformation compounds. Through hybrid technologies, the advantages of the methods are combined, leading to a maximization of contaminants removal. The review highlights the importance of installing combined wastewater treatment processes to reduce the amounts of pharmaceutical residues before the wastewater enters the environment. The use of advanced oxidation process, either as a pre-treatment or as a post-treatment combined with biological, adsorption, or filtration process is recommended as a promising option. Nevertheless, the optimum treatment methods for the pharmaceuticals-containing wastewater depends on the quality and quantity of wastewater, as well as on the pharmaceutical compounds residues and their hazardous effects.
10. Analysis of process parameters on energy utilization and environmental impact of hydrogen metallurgy
Journal of Cleaner Production, Volume 361, 10 August 2022, 132289
Abstract
Based on the heat energy and mass balance, the gas demand and carbon emission of per ton of direct reduced iron were calculated using a hydrogen-metallurgy process with an H2 and CO mixture as the reducing gas in the reduction temperature range of 800–1300 °C. The effects of the reduction temperature and H2 volume fraction on the gas demand and carbon were analyzed. The direct reduction process was evaluated based on the recovery rate of the reducing gas, gas energy efficiency, and heat recovery rate. The of the study results indicated that when the temperature does not exceed 900 °C, the minimum gas demand and lowest recovery rate of the reducing gas increase with an increase in the H2 volume fraction. When the temperature increases, the minimum gas demand and the lowest recovery rate of the reducing gas first decreased and then increased. When the reduction temperature was 1000 °C and the H2 volume fraction was 22%, the energy consumption reached its lowest value of 3.00 GJ/t. Increasing the H2 volume fraction or increasing the temperature of the hydrogen metallurgy process can effectively reduce the carbon emissions. In the all-hydrogen state, the higher the temperature, the lower the energy efficiency of the reducing gas. The thermal energy recovery rate decreased with an increasing H2 volume fraction and reduction temperature. The selection and design of the physical parameters of hydrogen metallurgy to achieve different goals would be more convenient if these calculations are used during the actual operation.
11. Research on the driving factors and carbon emission reduction pathways of China’s iron and steel industry under the vision of carbon neutrality
Journal of Cleaner Production, Volume 361, 10 August 2022, 132237
Abstract
Under the vision of carbon neutrality, China’s iron and steel industry (CISI) urgently needs to achieve low-carbon development. To formulate effective and targeted emission reduction policies for CISI, the driving forces of carbon dioxide (CO2) emissions and future emission reduction pathways in CISI are explored in this paper. The Logarithmic Mean Divisia Index (LMDI) method and the Mean Impact Value (MIV) technique are adopted to analyze the driving factors of CO2 emissions in CISI at historical and prospective dimensions, respectively. Furthermore, the extreme learning machine (ELM) model optimized by the bat algorithm (BA) is established to project the carbon emission reduction pathways of CISI during 2020–2050 under the business-as-usual (BAU) scenario, the low-speed, medium-speed, and high-speed development scenarios considering the constraint of the carbon neutrality target. The results reveal that production capacity and energy efficiency are essential drivers of CO2 emissions in CISI. Consequently, aimed at achieving carbon neutrality, CISI should focus on eliminating backward capacity and simultaneously accelerating the deployment of advanced technologies. Additionally, it is difficult to accomplish the carbon neutrality goal by 2060 under the BAU scenario. Conversely, under the optimal emission reduction pathway determined by the high-speed development scenario, CISI will reach its peak in 2022 with a peak value of 2143.42 million tons of CO2 (MtCO2). The average annual emission abatement rate during 2022–2050 is maintained at approximately 4.47% and the cumulative reduction rate in 2050 will exceed 70% compared to the base year 2019. CISI is required to develop more stringent emission reduction measures to achieve significant emission abatement. The crude steel production capacity should be reduced to 533 Mt in 2050 and the capacity utilization rate should be maintained beyond 80%. The energy consumption per ton of steel must be decreased to 264 Kg of coal equivalent (Kgce) in 2050.
12. Industrial coagglomeration, technological innovation, and environmental pollution in China: Life-cycle perspective of coagglomeration
Journal of Cleaner Production, Volume 362, 15 August 2022, 132280
Abstract
The coagglomeration of manufacturing and producer service industries and technological innovation plays an essential role in China’s booming economy. Considering the coordinated development goal of the environment and the economy, from the life-cycle perspective of industrial coagglomeration, this study empirically examines whether industrial coagglomeration has dynamic influences on environmental pollution and verifies the direct and indirect impact mechanisms based on the panel threshold model and mediation model. Panel data for China’s 30 provinces from 2008 to 2019 are employed. The results suggest that the impact of industrial coagglomeration on environmental pollution is positive and has significant threshold effects. As industrial coagglomeration deepens, its aggravating effect on environmental pollution presents an inverted S-shaped trend. The impact of industrial coagglomeration on technological innovation is negative. With the deepening of coagglomeration, the adverse effect gradually decreases. Additionally, technological innovation is conducive to the reduction of environmental pollution. It acts as a vital mediator between industrial coagglomeration and environmental pollution, and its mediating effect varies with the dynamic evolution of industrial coagglomeration. These conclusions show the importance of increasing industrial coagglomeration efficiency and stimulating the effective play of positive environmental and innovative externalities to realize the sustainable pursuit of economic and ecological benefits.
13. The pursuit of net-positive sustainability for industrial decarbonization with hybrid energy systems
Journal of Cleaner Production, Volume 362, 15 August 2022, 132349
Abstract
Signatories of the Paris Agreement are set to miss their climate targets. The net-zero pledges announced to date across many countries and private industries are insufficient to achieve carbon neutrality, which requires implementation of far-reaching and significantly scaled-up climate-positive actions. All technology options that pertain to deep decarbonization and carbon removal must be part of the mitigation portfolio. Transformative action plans must be established in which every individual/organization around the globe is an actor of changes in relation to net-zero goals. Such plans must involve governmental policy support but also encourage voluntary efforts to boost innovations, investments, initiatives, and behavioral changes. Recognition of these efforts is made quantifiable with the concepts of carbon handprint and net positivity.
This paper presents a carbon handprint perspective on characterizing the environmental benefits of hybrid energy systems (HESs) – a widely applicable solution to cleaner production leveraging the capabilities of a portfolio of low-carbon energy sources – that provide heat and electricity to industrial processes. First, the carbon handprint and net positivity concepts and their calculation approach are introduced. The state of the art of HES-enabled industrial cogeneration is then surveyed, and the greenhouse gas emission intensities of different energy sources that power HESs are compared. Next, drawing on a case study about a US chemical facility’s voluntary initiative to explore replacing its fossil fuel–based cogeneration infrastructure with a clean energy – generated HES, several technically viable scenarios are evaluated – especially those with small modular nuclear reactors – to illustrate how the positive-thinking handprint approach helps encourage and inform the search for widespread influence pathways in pursuit of net-positive sustainability. Finally, current knowledge gaps in the case study are identified, and opportunities to scale up the proposed handprint-based analysis are outlined with consideration of an expanded role of HESs in fulfilling climate objectives.
It is envisioned that like-minded decision makers in the industry sector and beyond will adopt this perspective and act synergistically to enhance their environmental stewardship through voluntary actions and make greater contributions to the planet’s climate future.
14. Blue hydrogen and industrial base products: The future of fossil fuel exporters in a net-zero world
Journal of Cleaner Production, Volume 363, 20 August 2022, 132347
Abstract
Is there a place for today’s fossil fuel exporters in a low-carbon future? This study explores trade channels between energy exporters and importers using a novel electricity-hydrogen-steel energy systems model calibrated to Norway, a major natural gas producer, and Germany, a major energy consumer. Under tight emission constraints, Norway can supply Germany with electricity, (blue) hydrogen, or natural gas with re-import of captured CO2. Alternatively, it can use hydrogen to produce steel through direct reduction and supply it to the world market, an export route not available to other energy carriers due to high transport costs. Although results show that natural gas imports with CO2 capture in Germany is the least-cost solution, avoiding local CO2 handling via imports of blue hydrogen (direct or embodied in steel) involves only moderately higher costs. A robust hydrogen demand would allow Norway to profitably export all its natural gas production as blue hydrogen. However, diversification into local steel production, as one example of easy-to-export industrial base products, offers an effective hedge against the possibility of lower European blue hydrogen demand. Looking beyond Europe, the findings of this study are also relevant for the world’s largest energy exporters (e.g., OPEC+) and importers (e.g., developing Asia). Thus, it is recommended that large hydrocarbon exporters consider a strategic energy export transition to a diversified mix of blue hydrogen and climate-neutral industrial base products.
15. The political economy of actively phasing out harmful industries: Lessons from resource-based sectors beyond fossil fuels
Energy Research & Social Science, Volume 90, August 2022, 102647
Abstract
The growing urgency of reducing fossil fuel consumption has spurred interest in the political economy dimensions of policies that aim to phase out existing industries. Much of this growing literature has focused on previous energy transitions and phase-outs. In this perspective article, I highlight the value of looking at cases beyond energy and fossil fuels to understand the dynamics of industry phase-out. To illustrate the point, I provide three short empirical case studies of industries in which policymakers have taken active steps to phase out or reduce specific industries. The cases are asbestos mining, tobacco cultivation, and cod fisheries in the UK’s Humber region.
The cases highlight the potential for economic diversification policies to both soften the blow faced by communities that are dependent on industries at the heart of phase-out policies, and to undermine the advocacy coalitions opposing phase-out policy. All three also suggest that cultural identity issues can play an important role in the politics of industry decline. The paper concludes by highlighting four avenues for future research into the political economy of actively phasing out harmful industries.
16. Integration of wastewater treatment units and optimization of waste residue pyrolysis conditions in the brominated phenol flame retardant industry
Journal of Industrial and Engineering Chemistry, Available online 8 August 2022
Abstract
Among the bromine flame retardants, tetrabromobisphenol A (TBBPA) is a highly effective flame retardant that can be used as both reactive and additive. However, the synthesis reaction of TBBPA has a low conversion rate and many brominated phenolic organics. Therefore, there is an urgent need to remove brominated organic pollutants produced in the process of producing flame retardants to reduce the harm to the environment and human beings and to reduce production costs. In this study, an efficient process was developed to treat the wastewater and residue generated in TBBPA production process, realizing its harmless and resource utilization. In the resource utilization system, through the ingenious design of solution mixing, precipitation separation, three-effect evaporation and concentration, valuable substances were extracted to realize the recovery and reuse of wastewater. In the harmless utilization process of hazardous waste residue, through high-temperature pyrolysis at 500 oC for 2 h after optimization with hypoxia-hyperoxia atmosphere modulation, it can avoid the production of dioxins and carbon black, effectively remove the organic impurities, realize the harmlessness and obtain high-quality sodium sulfate. This paper aims to propose a simple, efficient and feasible utilization system, including the three major technological processes of TBBPA production, integrated wastewater treatment and optimized the harmless treatment of waste residue to obtain sodium sulfate, so as to realize green TBBPA. Compared with the traditional TBBPA synthesis system, wastewater and waste residue treatment processes, the TBBPA quality is increased by 2% and the economic cost is reduced by 10%, which is of great significance to the development of the industry.
17. Enhancing energy efficiency of Indian industries: Effectiveness of PAT scheme
Energy Economics, Available online 4 August 2022, 106220
Abstract
India adopted Cap and Trade in energy intensity via a scheme called Perform Achieve and Trade (PAT) to improve the energy efficiency of energy intensive industries through target setting and allowing trade in energy saving certificates. The first cycle ran from April 2012 to March 2015, where the Bureau of Energy Efficiency assigned targets to identified firms in eight industrial sectors. This paper aims to examine the effectiveness of the PAT scheme in inducing firms to reduce energy intensity in the Cement, Fertilizer, and Pulp and Paper Industries. Using a difference-in-differences model, we do a firm level analysis for three industries over an 11 year period (2005 to 2015) and estimate the average treatment effect of the PAT scheme on the firms that were assigned the targets. We find that the PAT scheme improved the energy intensity of the designated firms by 2.7 percent and 1.6 percent in the cement and the fertilizer industry, respectively. The associated CO2 emission savings was about 22.5 million metric tons in the cement industry. However, the scheme was not effective in causing an additional decline in energy intensity in the pulp and paper sector. Another robust result is that the energy intensity of firms is declining in research and development investment.
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