Air pollution control has become one of the top priorities of China's “Ecological Civilization” development. As a quick response to the 2013 PM2.5 episodes, the Chinese Government issued the “Air ...Pollution Prevention and Control Action Plan” as the national strategy and roadmap for air quality improvements consisting of phased quantitative targets and concrete measures. Taking this into account, this study explores the spatiotemporal variations of the five conventional pollutants—PM2.5, PM10, SO2, NO2, and O3—as well as the Air Quality Index and primary pollutants in 338 Chinese cities from 2013 to 2017 in order to comprehensively understand China's current air pollution situation and evaluate the effectiveness of the Action Plan. The results indicate that: (1) the overall air quality has been significantly improved, with the concentrations of PM2.5, PM10, and SO2 decreasing noticeably, although the still high PM level, the dramatically increasing O3 concentration, and the stagnant amounts of NO2 present further challenges, along with the intensification of regional compound air pollution problems; (2) in contrast to the three key regions under the Action Plan exhibiting significant decreases in PM and SO2, the Fen-Wei Plain (FWP) is suffering from serious compound pollution, suggesting that there is an urgent need for the development of a regional joint prevention and control mechanism in the FWP and similar areas; (3) with the exception of the common pollution hot spots mainly concentrated in the FWP as well as Beijing-Tianjin-Hebei (BTH) and its surrounding regions, the distribution of each pollutant exhibited remarkable spatial heterogeneity due to their distinctive emission sources, a finding that strongly indicates the need for regionally differentiated management; and (4) the most frequent primary pollutant at the national level was O3, followed by PM2.5 and PM10. In the Wuhan Metropolitan Area (WHM), Changsha-Zhuzhou-Xiangtan Metropolitan Area (CZT), and Sichuan-Chongqing Region (CY), PM2.5 pollution is playing the dominant role, while in the FWP, BTH, Yangtze River Delta region (YRD), and Pearl River Delta region (PRD), the synergistic control of PM2.5 and O3 pollutants is urgently needed as soon as possible, which will require that more attention be paid to emission mitigation in the transportation sector, as well as the synergistic control of NOx and VOC emissions.
•Overall air quality improved dramatically, but non-attainment is still widespread.•Regional compound air pollution problems are intensifying, dominated by PM and O3.•Spatial disparity of pollutants requires regionally differentiated management.•Fen-Wei Plain suffers from the most serious air pollution along with 2 + 26 cities.•Synergistic control of NOx and VOCs is greatly needed.
Achieving carbon neutrality before 2060 newly announced in China are expected to substantially affect air quality. Here we project the pollutants emissions in China based on a carbon neutrality ...roadmap and clean air policies evolution; national and regional PM2.5 and O3 concentrations in 2030 (the target year of carbon peak), 2035 (the target year of “Beautiful China 2035” launched by the Chinese government to fundamentally improve air quality) and 2060 (the target year of carbon neutrality) are then simulated using an air quality model. Results showed that compared with 2019, emissions of SO2, NOx, primary PM2.5, and VOCs are projected to reduce by 42%, 42%, 44%, and 28% in 2030, by 57%, 58%, 60%, and 42% in 2035, by 93%, 93%, 90% and 61% in 2060 respectively. Consequently, in 2030, 2035, and 2060, the national annual mean PM2.5 will be 27, 23, and 11 μg m−3; and the 90th percentile of daily 8-h maxima of O3 (O3-8h 90th) will be 129, 123, and 93 μg m−3; 82%, 94%, and 100% of 337 municipal cities will reach the current national air quality standard, respectively. It's expected that the “Beautiful China 2035” target is very likely to be achieved, and about half of the 337 cities will meet the current WHO air quality guideline in 2060. In the near future, strict environmental policies driven by “Beautiful China 2035” are needed due to their substantial contribution to emission reductions. By 2060, the low-carbon policies driven by the carbon neutrality target are expected to contribute to larger than 80% of reductions in PM2.5 and O3-8h 90th concentrations relative to the 2020 levels, implying that more attention could be paid to low-carbon policies after 2035. Our research would provide implications for future co-governance of air pollution and climate change mitigation in China and other developing countries.
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•The air quality cobenefits of achieving China's carbon neutrality before 2060 was quantitatively investigated.•This study proposed a mid-to-long-term air quality improvement pathway until 2060 of China (CAEP-CAP).•End-of-pipe controls can greatly improve air quality before 2035, while low-carbon policy will be more critical after 2035.
•Cement industry has become one of the key industrial emission sectors in China.•All the 1574 Chinese cement factories were investigated for their CO2 emissions.•Yangtze River Delta region is the key ...region of cement emissions.•Ownership of cement enterprises should be carefully considered in the policy preparation.
This paper targets to evaluate the overall CO2 emissions from cement industry based on the detailed information of China’s total 1574 cement enterprises in 2013. State-owned enterprises and large scale enterprises dominate the total CO2 emissions, accounting for 59.35% and 61.87% of the total emissions respectively. The process emission intensities of all enterprises ranged among 500–600kg CO2/t clinker, while the energy emission intensities varied among different enterprises, with an average level of 348kg CO2/t clinker and a standarddeviation of 233kg CO2/t clinker. The average CO2 emissions performance of China’s cement enterprises (806kg CO2/t clinker) is 35kg CO2/t clinker lower than the global level in 2013. The CO2 emissions intensity of the best 20th clinker production, which is lower than the IEA’s 2020 target, could be the entry threshold for future new enterprises and top runner bench mark for the existing enterprises. The Yangtze River Delta region is the most important hotspot of the cement CO2 emissions. Wuhu & Tongling are the hottest emission centers, with an average of 8288ton of CO2 emissions per square kilometers. Ownership of cement enterprises should be carefully considered in the policy preparation. Favorable policies could focus on medium sized facilities and facilities in the ENDI type along the Silk Road Economic Belt.
Developing localized climate mitigation strategies needs an understanding of how global consumption drives local carbon dioxide (CO
) emissions with a fine spatial resolution. There is no study that ...provides a spatially explicit mapping of global carbon footprint in China-the world's largest CO
emitter-simultaneously considering both international and interprovincial trade. Here we map CO
emissions in China driven by global consumption in 2012 at a high spatial resolution (10 km × 10 km) using a detailed, firm-level emission inventory. Our results show that the carbon footprints of foreign regions in China are concentrated in key manufacturing hubs, including the Yangtze River Delta, Pearl River Delta, and North China Plain. Approximately 1% of the land area holds 75% of the global carbon footprint in China. The carbon footprint hotspots in China identified are the key places in which collaborative mitigation efforts between China and downstream parties that drive those emissions.
As the world’s factory, China has enjoyed huge economic benefits from international export but also suffered severe environmental consequences. Most studies investigating unequal environmental ...exchange associated with trade took China as a homogeneous entity ignoring considerable inequality and outsourcing of pollution within China. This paper traces the regional mismatch of export-induced economic benefits and environmental costs along national supply chains by using the latest multiregional input-output model and emission inventory for 2012. The results indicate that approximately 56% of the national GDP induced by exports has been received by developed coastal regions, while about 72% of air pollution embodied in national exports, measured as aggregated atmospheric pollutant equivalents (APE), has been mainly incurred by less developed central and western regions. For each yuan of export-induced GDP, developed regions only incurred 0.4–0.6 g APE emissions, whereas less developed regions from western or central China had to suffer 4–8 times the amount of emissions. This is due to poorer regions providing lower value added and higher emission-intensive inputs and having lower environmental standards and less efficient technologies. Our results may pave a way to mitigate the unequal relationship between developed and less developed regions from the perspective of environment-economy nexus.
•A new approach for designing a green UHPC is proposed.•Two mathematical models based on DOMD and GA-ANN are built.•GA-ANN exhibits higher prediction accuracy compared with DOMD.•The GA-ANN is ...employed for mix design of UHPC successfully.•A green UHPC with advanced properties and dense matrix is developed.
This paper presents a new approach for designing a green Ultra-High Performance Concrete (UHPC) with advanced particles packing meso-structure. To achieve this goal, two mathematical models based on D-Optimal Mixture Design (DOMD) and Genetic Algorithm based Artificial Neural Network (GA-ANN) are firstly established. After detailed comparison, it is demonstrated that the GA-ANN has higher accuracy and practicability compared to DOMD. To experimentally verify that the GA-ANN approach is suitable to be utilized in producing green UHPC, some UHPC specimens are developed based on this model, and their properties (workability, mechanical properties, pore structures and ecological characteristics) are investigated. The obtained experimental results show that the optimized UHPC has higher wet packing density and lower porosity, leading to excellent mechanical properties. Moreover, based on economic and environmental evaluation, the newly developed UHPC exhibits lower cost and environmental impact, something that makes it a sustainable construction product.
•Novel chelating sponge PVA-M-H is prepared and characterized.•PVA-M-H has high adsorption capacity for Ni(II) and Cd(II).•Adsorption mechanisms of Ni(II) and Cd(II) on PVA-M-H are ...elucidated.•Effects of Ca2+ and Mg2+ on absorbing Ni(II) and Cd(II) are elucidated.•PVA-M-H performs perfect regeneration capacity after multiple uses.
Novel chelating sponge (PVA-M-H) was prepared with polyvinyl alcohol by graft polymerization and nucleophilic substitution. E.A, SEM, FT-IR, 13CNMR, and XPS analyses were used to characterize PVA-M-H. The equilibrium adsorption capacities of PVA-M-H for Ni(II) and Cd(II) were 65.39 and 125.11mgg−1, respectively. Within the range of 278–308K, the adsorption enthalpy changes of Ni(II) and Cd(II) on PVA-M-H were about 36.39–37.72kJmol−1, and the free energy were about −13.27 to −1.7kJmol−1. Both pseudo-first- and -second-order equations fit the adsorption kinetic curves well, and the initial adsorption rates of Ni(II) and Cd(II) onto PVA-M-H were 17.83 and 34.81mg (gmin)−1, respectively. Although the presence of alkali-earth metal ions in solution decreased Ni(II) and Cd(II) removal, PVA-M-H still retained more than 60 and 80% of its adsorption capacity even as the concentration of Ca2+ and Mg2+ was up to 10mmolL−1, respectively. Both 0.1M HCl and 0.1M EDTA solution could desorb Ni(II) and Cd(II) from PVA-M-H effectively, and the adsorption capacity of PVA-M-H for Ni(II) and Cd(II) could still maintain more than 90% level without any obvious decrease at the fifth cycle.
Abstract
Key targets of the sustainable development goals might be in contradiction to each other. For example, poverty alleviation may exacerbate air pollution by increasing production and ...associated emissions. This paper investigates the potential impacts of achieving different poverty eradication goals on typical air pollutants in China by capturing household consumption patterns for different income groups and locations, and linking it to China’s multi-regional input-output table and various scenarios. We find that ending extreme poverty, i.e. lifting people above the poverty line of USD 1.90 a day in 2011 purchasing power parity (PPP), increases China’s household emissions by only less than 0.6%. The contribution increases to 2.4%–4.4% when adopting the USD 3.20 PPP poverty line for lower-middle-income countries. Technical improvements in economic sectors can easily offset poverty-alleviation-induced emissions in both scenarios. Nevertheless, when moving all impoverished residents below the USD 5.50 PPP poverty line for upper-middle-income countries, household emissions in China would increase significantly by 18.5%–22.3%. Counteracting these additional emissions would require national emission intensity in production to decrease by 23.7% for SO
2
, 13.6% for NO
x
, 82.1% for PM
2.5
, and 58.0% for PM
10
. Required synergies between poverty alleviation and emission reduction call for changes in household lifestyles and production.
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