Typical Industrial City Research Articles

The scale effects of symbiotic relationships under complex driving factors: An empirical study in China

AbstractSymbiotic relationships between enterprises help mitigate resource and environmental impacts of industrial activities via exchanging waste or by‐products as material inputs among each other. However, the emergence of such symbiotic relationships under complex driving factors across different geographical scales remains hitherto not well understood. Here, we provide an analytic framework including a random forest model and Shannon index, to systematically describe and explain the scale effects of driving factors underlying the symbiotic relationships. Based on a questionnaire survey for 324 enterprises in Chun'an, a typical industrial city in eastern China, we applied this analytical framework. The results show that, first, the quantity of symbiotic relationships exhibits an inversely proportional function across various geographical scales. Second, there exist significant differences in the dominant factors at different scales. Finally, the diversity of importance of factors and the emergence of symbiotic relationships exhibit a consistent trend of fluctuation, providing evidence for the explanatory potential of our proposed analytical framework for the driving mechanisms of emergence. We find that when enterprises are simultaneously affected by multiple driving factors with potent forces (referred to as the diversity of importance), symbiotic behaviors are more likely to occur. Moreover, our results suggest that fostering symbiotic relationships necessitates considering the variations in driving factors across different scales comprehensively and formulating targeted promotional measures tailored to the specific driving factors of different enterprise types. Our proposed framework would help to maximize industrial symbiosis potentials in a specific region.

Seasonal trends and light extinction effects of PM2.5 chemical composition from 2021 to 2022 in a typical industrial city of central China

This study investigates the concentrations, chemical compositions, and sources of PM2.5 in Huangshi, China. Daily average PM2.5 levels ranged from 8.43 to 193.08 μg m−3, with an annual mean of 54.13 μg m−3, exceeding China's annual secondary standard of 35 μg m−3. Seasonal mean concentrations peaked in winter and were lowest in summer. Organic carbon (OC) and elemental carbon (EC) had annual means of 4.89 μg m−3 and 0.94 μg m−3, respectively. Water-soluble inorganic ions (WSIIs) accounted for 52.17% of PM2.5, with NO3−, SO42−, and NH4+ being the major components. The NO3−/SO42− ratio averaged 1.65, indicating a transition from coal combustion to vehicle emissions as the primary pollution source. Chemical mass reconstruction revealed that NH4NO3, (NH4)2SO4, and organic matter (OM) accounted for 65.3% of PM2.5 mass. Seasonal variations in light extinction (bext) highlighted the impact of secondary inorganic salts on visibility, with an annual average bext of 346.30 ± 246.98 Mm−1. Airmass clusters and potential source region analysis suggested PM2.5 and its components were primarily originated from local and nearby regions. These findings underscore the effectiveness of local pollution control measures, changing pollution sources, and the necessity for targeted emission controls to improve air quality and visibility in urban areas.

Determining the priority control sources of heavy metals in the roadside soils in a typical industrial city of North China

Heavy metals (HMs) in roadside soils (RS) are closely related to urban ecosystem and human health, but priority control sources and eco-health risks of HMs remain unclear. We explored pollution sources of HMs using positive matrix factorization (PMF), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), and random forest (RF), and assessed their source-specific eco-health risks. The combination of PMF, SEM-EDS and RF indicated that pollution sources of HMs were coal combustion (27.99%), construction materials (30.15%), and traffic emissions (41.86%). SEM-EDS revealed RS particles were identified by a combination of physical (spherical, porous rounded, crustal flake, crustal rounded and irregular particles) and elemental surface characteristics (O, C, Si, Al, Fe, Ca, Mg, K, Zn, Cu, and Mn). RF highlighted road network density, residential density, and industrial density had significant importance influence on pollution sources. Approximately 72.35% of soil samples were at a low ecological risk with traffic emissions being the major contributor. Non-carcinogenic risks had a minimal effect, but carcinogenic risks were at a cautionary level with coal combustion being the highest contributor. Overall, coal combustion and traffic emissions were regarded as priority control sources of HMs. These findings provided effective guidance for soil pollution prevention and risk control.

Ambient volatile organic compounds in a typical industrial city in southern China: Impacts of aromatic hydrocarbons from new industry

New industrial parks, including fine chemical, medical manufacturers, etc., are emerging in modern cities in China, whereas their emissions and impacts have not been fully illuminated. In this study, ambient volatile organic compounds (VOCs) in Huizhou were measured in three functional zones, namely new industrial, roadside, and residential zones. The average mixing ratios of total VOCs were as follow: industrial (56.22 ± 15.06 ppbv) > roadside (39.30 ± 12.96 ppbv) > residential (26.03 ± 7.31 ppbv). The ozone formation potential (OFP) and secondary organic aerosol formation potential (SOAP) of VOCs in the industrial zone were 1.5–2.3 and 1.7–3.1 times those in the other zones, respectively. Aromatics contributed the most to OFP (39.8 % - 44.8 %) and SOAP (78.9 % - 91.0 %), with much less contributions to VOCs mixing ratios (18.3 % - 21.2 %). Naphthalene was the most abundant aromatic species across the three zones and ranked among the top contributors to OFP and SOAP among all VOCs species. Source apportionment identified that new industrial emissions and solvent use was the largest VOCs contributor in the industrial zone (53.9 %), traffic-related emissions dominated in the roadside zone (40.7 %), while new industrial and traffic-related emissions contributed similar in the residential zone (32.9 % and 34.7 %, respectively). The carcinogenic and non-carcinogenic risks of hazardous VOCs were above the acceptable threshold, primarily due to new industrial and traffic-related emissions. Our results suggested to strengthen the control of new industrial emissions and aromatics sources in Huizhou city to improve air quality and protect human health.

Advancing urban sustainability transitions: A framework for understanding urban complexity and enhancing integrative transformations

Rapid urbanization and industrialization with their negative repercussions draw attention to the need for urban sustainability. This research built on the urban systems understanding linked with resource utilization, environmental effects, people-environment interactions, and adaptive management by integrating quantitative modelling of urban metabolism with a qualitative investigation into human responses. A hybrid methodology was applied in a typical industrial city of Jinchang, China, which exemplified a model of how complex urban dynamics link to and inform sustainability transitions. The study found that Jinchang City had taken on an unsustainable trajectory underpinned by continuous growth of material consumption, whereas a potential for sustainability transitions was also observed in decoupled negative material outputs, improved material efficiency, and environment regeneration collectively. The challenges in industrial cities have been framed in terms of development model lock-in, conceptual and institutional constraints, innovation and human capital deficiencies, and governance failure. The research proposed a government-led transformation system that integrates multi-level and multi-perspective transformations and management employing discipline insights to facilitate urban sustainability transitions. This involves governance, economic and technological innovations, social transformations, and implementations, in which urban governance and public engagement are essential elements for adapting to undesirable difficulties and exploring locally appropriate strategies. This research provided a theoretical and empirical basis along with scientific and policy implications, which contributed to the developing interdisciplinary knowledge on the understanding of complex urban systems and provided insights into real-world sustainability solutions.

Evidence for sustainably reducing secondary pollutants in a typical industrial city in China: Co-benefit from controlling sources with high reduction potential beyond industrial process

Under China’s strict industrial control measures, the reduction of secondary pollutants (O3 and secondary organic aerosols [SOA]) and precursors (volatile organic compounds [VOCs] and NOx) caused by industrial processes has encountered bottlenecks. In this study, the net O3 formation rate (Net [O3]) in summer and the self-reaction rate between peroxy radicals (Self-Rnxs) in winter are used to characterize the formation potentials of O3 and SOA, respectively. Assuming that the precursor reduction ratio based on emission inventories is approximately equal to that based on observed concentrations, this study combines emission inventory and observation-based model (OBM) methods to indicate the potential source of secondary pollutants reduction. The findings show that strict control measures implemented by local governments, particularly those targeting industrial processes and fossil fuel combustion, are effective in reducing VOCs and NOx emissions during summer, and the two sources result in 3.8 % and 5.3 % decrease in the Net (O3), respectively. Similarly, control measures focusing on industrial processes help to significantly reduce VOCs emissions during winter, resulting in an 8.0 % decrease in Self-Rnxs. However, current measures for industrial processes are stringent and have little potential for further reduction. Therefore, additional sources with higher reduction potentials beyond industrial processes should be subject to stringent controls in industrial cities. Given the limited emission reduction potential associated with industrial processes, this study provides perspectives for sustained reduction of secondary pollutants in industrial cities.

Investigation into the nocturnal ozone in a typical industrial city in North China Plain, China

Ozone (O3) concentrations usually peak at midday by photochemical reactions and gradually decline after sunset due to chemical destruction and dry deposition. However, an increase in the frequency of elevated nocturnal ozone enhancement (NOE) and high nocturnal ozone value (HNOV) has been frequently observed in urban areas of eastern China, but the reasons are not well understood. In this study, taking a typical industrial city, ZiBo as a case study, we analyzed the trends, characteristics, and causes of the NOE and HNOV events in historical years by combining observations and model simulations. During the warm season (April–September) of 2017–2023, HNOV events are accompanied by low humidity, high temperature, large friction velocity, and a high boundary layer (52 days in total), whereas NOE events coincide with increases in humidity, wind speed, friction velocity, and boundary layer height (141 days in total). During the HNOV and NOE events, the nighttime average concentrations of Ox were 77 ± 7 and 12 ± 6 μg m−3 higher than the non-nocturnal O3 period, indicating enhanced atmospheric oxidizing capacity during nighttime. The modeling results indicate that both the HNOV and NOE events were mainly driven by vertical mixing and regional transport. We selected a typical period with high O3 pollution and frequent NOE and HNOV events to conduct the modeling study. Three typical nocturnal O3 events are identified: Case I was mainly driven by horizontal transport; while in the two subsequent cases, the vertical transport contribution was 80 μg m−3 h−1 (20:00 LT on June 21, 2021) and 35 μg m−3 h−1 (02:00 LT on June 26, 2021), respectively. Our study reveals that the O3 pollution in industrial cities has been extending to nighttime, primarily attributed to vertical mixing and horizontal transport within the boundary layer. This highlights the critical role of implementing regional joint control action to reduce primary emissions and eliminate residual ozone.

Microscopic Characterization of Individual Aerosol Particles in a Typical Industrial City and Its Surrounding Rural Areas in China.

Transmission electron microscopy was used to analyze individual aerosol particles collected in Lanzhou (urban site) and its surrounding areas (rural site) in early 2023. The results revealed that from the pre-Spring Festival period to the Spring Festival period, the main pollutants at the urban site decreased significantly, while the PM2.5 and SO2 concentrations increased at the rural site. During the entire sampling period, the main particles at the urban site were organic matter (OM), secondary inorganic aerosols (SIA), and OM-SIA particles, while those at the rural site were OM, SIA, and soot particles. The degree of external mixing of single particles in both sites increased from the pre-Spring Festival period to the Spring Festival period. The proportion of the OM particles increased by 11% at the urban site, and the proportion of SIA particles increased by 24% at the rural site. During the Spring Festival, the aging of the soot particles was enhanced at the urban site and weakened at the rural site. At the urban site, the SIA particle size was more strongly correlated with the thickness of the OM coating during the pre-Spring Festival period, while the correlation was stronger at the rural site during the Spring Festival.

Characterization of PM2.5 Carbonaceous Components in a Typical Industrial City in China under Continuous Mitigation Measures.

The goals of the "dual carbon" program in China are to implement a series of air pollution policies to reduce the emission of carbon-bearing particulate matter (PM). Following improvements in the reduction in carbon emissions in Handan City, China, fine particulate matter (PM2.5) was collected in the winters from 2016 to 2020 to characterize the concentrations and sources of carbonaceous components in PM2.5. Trend analysis revealed that both organic carbon (OC) and elemental carbon (EC) concentrations significantly decreased. The proportion of total carbon aerosol (TCA) in PM2.5 decreased by 47.0%, highlighting the effective reduction in carbon emissions. Secondary organic carbon (SOC) concentrations increased from 2016 (12.86 ± 14.10 μg·m-3) to 2018 (36.76 ± 21.59 μg·m-3) and then declined gradually. SOC/OC was larger than 67.0% from 2018 to 2020, implying that more effective synergistic emission reduction measures for carbonaceous aerosol and volatile organic compounds (VOCs) were needed. In the winters from 2016 to 2020, primary organic carbon (POC) concentrations reduced by 76.1% and 87.6% under a light/moderate pollution period (LP) and heavy/severe pollution periods (HPs), respectively. The TCA/PM2.5 showed a decreasing trend under LP and HP conditions, decreasing by 42.1% and 54.7%, respectively. Source analysis revealed that carbonaceous components were mainly from biomass burning, coal combustion and automotive exhaust emissions in the winters of 2016 and 2020. OC/EC and K+/EC analysis pointed out that air pollutant reduction measurements should focus on rectification biomass fuels in the next stage. Compared with 2016, the contributions of automotive exhaust emissions decreased in 2020. OC and EC concentrations decreased due to control measures on automotive exhaust emissions.

Identification and seasonal variation of specific particulate bound (halogenated) polycyclic aromatic hydrocarbons in air from different metal industrial parks in Northwest China.

During the process of industrial heating, a large amount of polycyclic aromatic hydrocarbons (PAHs) and their halogenated compounds (Cl/Br-PAHs) can be formed. However, there is still limited understanding of the chemicals from different metal smelting industrial parks. This study evaluated the seasonal variations, composition profiles, and source allocations of the atmospheric particulate-bound PAHs and Cl/Br-PAHs in different metal industrial parks in a typical industrial city in northwest China. The results showed that the main PAHs produced by metal smelting were low molecular weight isomers, and the concentrations of Cl-PAHs were lower compared to Br-PAHs. The main Br-PAHs were 1-Br-Pyr and 4-Br-Pyr, while 9-Cl-Fle, 1-Cl-Pyr, and 6-Cl-BaP were the dominated Cl-PAH isomers. No significant difference was found in the concentrations among the sites, whereas the levels of the target chemicals were higher during cold months compared to warm months. The main source of PAHs was coal combustion and gasoline vehicle emission during metal smelting, and that of Cl/Br-PAHs was also industrial coal burning. In addition to the primary source, the secondary chlorination of parent PAHs was also a significant source of Cl-PAHs in the production of high purity aluminum. This study suggests that Cl-PAHs and Br-PAHs may behave differently in the atmosphere.

The various synergistic impacts of precursor emission reduction on PM2.5 and O3 in a typical industrial city with complex distributions of emissions

The synergistic responses of O3 and PM2.5 to their common precursors remain unclear within industrial cities with complex emissions. In this study, hundreds of scenarios of jointly reduced local NOx and VOCs emissions were designed along with the source apportionment techniques embedded in the Comprehensive Air quality Model with extensions (CAMx) system to explore the locally formed O3 and PM2.5 sensitivities to the reduced emissions of NOx and VOCs. The results indicate that locally formed O3 and PM2.5 are more connected to local emissions, resulting in unique formation sensitivities. Local O3 formation is usually in a transitional regime and transferred to VOC-limited condition under O3-polluted conditions due to high VOC emissions. Locally formed O3 and PM2.5 vary largely in different functional regions due to different emission feature and meteorological condition. When reducing VOCs emissions alone, an increase in PM2.5 formation could be observed due to the increase in the formation of nitrate resulting from reduced competition of NOx in O3 formation. To reduce PM2.5 and O3 concentrations simultaneously, specific ratios of NOx reduction percentage to VOC reduction percentage should be considered to different functional regions under different pollution levels. This research highlights the importance to conduct targeted sensitivity tests for emission reduction in different functional zones with complex emission features for the coordinated control of O3 and PM2.5 pollution in typical industrialized cities.

Process of mercury accumulation in urban strip river artificial wetland ecosystems: a case study of Changchun, a typical industrial city in Northeast China.

Mercury (Hg), as a global pollutant, is persistent, migratory, insidious, highly biotoxic and highly enriched, and is widely distributed in the atmosphere, hydrosphere, biosphere and lithosphere. Wetland ecosystems, as active mercury reservoirs, have become the most important sources and sinks of heavy metal mercury. Distinguished from natural wetlands, artificial wetlands located in urban sections of rivers face problems such as diverse urban pollution sources and complex spatial and temporal changes. Therefore, in this study, five intermittently distributed artificial wetlands were selected from the upstream to the downstream of the Changchun section of the Yitong River, a tributary of the Songhua River basin in the old industrial base of Northeast China. The mercury levels in the water bodies, sediments and plants of the artificial wetlands were collected and tested in four quarters from April 2023 to analyse the spatial and temporal distribution characteristics of total mercury. The results showed that the mercury levels in the water bodies, sediments and plants of the five wetlands showed a fluctuating trend with the river flow direction and had certain spatial and temporal distribution characteristics. This phenomenon was attributed to the sinking of external mercury pollution sources. In general, the wetland ecosystems showed a decreasing trend in the total Hg output of the downstream watershed. This may be due to the retention of particulate matter by aquatic plants in artificial wetlands to regular salvage of dead aquatic plants. At the same time urbanization and industrialization affect mercury levels in aquatic environments, so the risk of residential exposure needs to be looked at.

Source apportionment of black carbon using an advanced Aethalometer model in a typical industrial city of China

Black carbon (BC) aerosol can lead to adverse health effects and drive climate change; therefore, the characteristic research and identification of BC sources are essential for lowering emissions. In this study, equivalent black carbon (eBC) measurement was performed using a seven-wavelength Aethalometer (AE33) at an urban site in a typical industrial city (Zibo) of Northern China for the first time. The monitoring was performed from February 2021 to January 2022. The mass absorption cross-section (MAC) of AE33 was optimised using the online elemental carbon (EC) data, and eBC was corrected using the MAC. The corrected annual BC concentration was 1.72 ± 1.18 µg/m3. The diurnal variation of BC depicted a bimodal distribution. Furthermore, the BC concentration on weekends was 18 % lower than on weekdays. The diurnal variation and weekend effect reflect the critical contributions of traffic emission to BC concentration. The source apportionment of BC was calculated by a constraining Aethalometer model, which restricted the Ångström exponent using the online potassium ions. The results revealed that BC was not significantly affected by biomass burning (BCbb) in Zibo. The relative contribution of BCbb was higher in winter than in other seasons. The daily morning peak of BC was primarily influenced by traffic sources, whereas the contribution of biomass burning increased after 17:00 in the evening peak. Our findings suggest that it is more important to control fossil fuel sources for BC emission reduction in Zibo, while it is necessary to strengthen the control of biomass combustion sources in winter.

Enhanced VOC emission with increased temperature contributes to the shift of O3-precursors relationship and optimal control strategy

Assessing the impact of anthropogenic volatile organic compounds (VOCs) on ozone (O3) formation is vital for the management of emission reduction and pollution control. Continuous measurement of O3 and the major precursors was conducted in a typical light industrial city in the YRD region from 1 May to 25 July in 2021. Alkanes were the most abundant VOC group, contributing to 55.0% of TVOCs concentration (56.43 ± 21.10 ppb). OVOCs, aromatics, halides, alkenes, and alkynes contributed 18.7%, 9.6%, 9.3%, 5.2% and 1.9%, respectively. The observational site shifted from a typical VOC control regime to a mixed regime from May to July, which can be explained by the significant increase of ROx production, resulting in the transition of environment from NOx saturation to radical saturation with respect to O3 production. The optimal O3 control strategy should be dynamically changed depending on the transition of control regime. Under NOx saturation condition, minimizing the proportion of NOx in reduction could lead to better achievement of O3 alleviation. Under mixed control regime, the cut percentage gets the top priority for the effectiveness of O3 control. Five VOCs sources were identified: temperature dependent source (28.1%), vehicular exhausts (19.9%), petrochemical industries (7.2%), solvent & gasoline usage (32.3%) and manufacturing industries (12.6%). The increase of temperature and radiation would enhance the evaporation related VOC emissions, resulting in the increase of VOC concentration and the change of ROx circulation. Our results highlight determination of the optimal control strategies for O3 pollution in a typical YRD industrial city.

Effects of significant emission changes on PM2.5 chemical composition and optical properties from 2019 to 2021 in a typical industrial city of eastern China

Restrictions on emission controls were implemented in China to cope with the outbreak of the Coronavirus Disease 2019 (COVID-19), providing a chance to study the impacts of anthropogenic emissions on air quality. Subsequently, three-year measurements of PM2.5 chemical composition and light absorption were conducted in a typical megacity (Suzhou) of the Yangtze River Delta in China from 2019 to 2021. The annual observation period was divided into four different stages: Normal Days, Chinese New Year, Lockdown, and Work Resumption. Our results show that the concentrations of PM2.5 composition (e.g., SO42−, NO3−, OC, and EC) and gas species (e.g., SO2, NO2, and CO) gradually decreased from 2019 to 2021, associated with emission reduction. During the four stages, the COVID-19 lockdown period had the lowest concentrations of PM2.5, indicating that strict emission control could significantly improve the air quality. The significant increase in O3 during the COVID-19 lockdown period is likely due to the reduced NO emission from the traffic. The Normal Days in 2020 had the highest mass loadings of SO42−, NO3−, NH4+, OC, and EC, while the mass concentrations of SO42−, NO3−, NH4+, Cl−, and Na+ in the Lockdown were the lowest. Meanwhile, aerosol light absorption has decreased yearly, and significant decreases in light absorption were observed during the COVID-19 lockdown. The high values of Absorption Ångström exponent (AAE) observed in Suzhou (ranging from 1.3 to 1.4), indicated that brown carbon played critical contributions to the light absorption. The mass concentration and fraction of fuel fossil were significantly higher than that of biomass burning during the entire campaign. The remarkable decline of fuel fossil BC during the COVID-19 lockdown can be attributed to the closure of factories and the reduction of vehicle emissions. The potential contribution source function analysis suggests a notable regional variation in the sources of fossil fuel and biomass combustion. Our results highlight that strict emission control could provide a positive direction for air pollution mitigation campaigns.

Analyzing ozone formation sensitivity in a typical industrial city in China: Implications for effective source control in the chemical transition regime

Volatile organic compounds (VOCs) play a major role in O3 formation in urban environments. However, the complexity in the emissions of VOCs and nitrogen oxides (NOx) in industrial cities has made it challenging to identify the key factors influencing O3 formation. This study used observation-based-model (OBM) to analyze O3 sensitivities to VOCs and NOx during summer in a typical industrial city in China. The OBM model results were coupled with a receptor model to analyze the sources of O3. Higher concentrations of O3 precursors were observed during polluted periods indicating that precursor accumulation contributed to the higher maxima of the net ozone formation rate and HOx concentrations. Analyses of ROx· budgets and relative incremental reactivity (RIR) indicated that O3 production is in a chemical transition regime and was sensitive to both VOCs and NOx. Results from Positive Matrix Factorization (PMF) analysis indicated that gasoline vehicle emissions, industrial processes, and coal combustion were major sources of O3 precursors. The sensitivities of O3 production to these sources depend on if both VOC and NOx sensitivities are considered. If only VOCs sensitivity is considered, in contrast, the contribution of anthropogenic sources to O3 production was significantly underestimated. This study highlights the importance of accounting for both VOCs and NOx sensitivities when O3 chemistry is in a transition regime in O3 production attribution studies.

PM2.5-bound heavy metals in a typical industrial city of Changzhi in North China: Pollution sources and health risk assessment

Heavy metal contamination in fine particulate matter (PM2.5) emitted in industrial cities is extremely severe. Hence, determining their pollution sources apportionment is critical to inform effective pollution control strategies for reducing the risks associated with heavy metals in PM2.5. This study comprehensively investigated the characteristics, source apportionment, and health risks associated with heavy metals in PM2.5 at three monitoring stations—Jiance, Qinghua, and Shenjiju—in Changzhi, a typical industry city in China, during three seasons: autumn and winter of 2017 and summer of 2018. The daily average concentrations of PM2.5 (65.68 μg m−3) during the study period were lower than the second-grade limit value established in China (75 μg m−3). The highest mean PM2.5 concentrations were observed during winter (72.45 μg m−3) and at the Jiance station (64.51 μg m−3), respectively. At Qinghua station, vehicle emissions contributed more V to PM2.5, whereas Jiance station showed higher levels of Pb and Zn from coal combustion. In autumn, there was an increased in the Fe content in PM2.5 from vehicle emissions, whereas elevated concentrations of Cr and Ni from industry sources were observed in summer. According to the results of a positive matrix factorization, the main sources of PM2.5-bound heavy metals in Changzhi were coal combustion (34.3%), vehicle emissions (30.9%), fugitive dust (21.8%) and industry (13.0%). The major sources during autumn, winter, and summer were vehicle emissions (39.0%), coal combustion (35.0%), and industrial emissions (61.7%), respectively, showing a clear seasonal pattern. At both the Jiance station and Shenjiju station, extensive coal-based heating was the primary source of emissions, whereas vehicle emissions were the main source of emissions at QH owing to its high levels of traffic. The total hazard quotient (HQ) values for heavy metals were below the safe level (HQ = 1); but the carcinogenic risks (CR) exceed the lower limit of tolerance (1E-6). Stronger emissions from industrial sources in summer and the large amount of coal combustion for heating at the Jiance station are possible reasons for the higher health risk of heavy metals. Identification the source of PM2.5-bound heavy metals could support the targeted reduction of associated emissions, consequently helping alleviate heavy metals contamination and control associated risks to human health.

Pollution Characteristics and Source Analysis of Carbonaceous Components in PM2.5 in a Typical Industrial City

Pollution Characteristics and Source Analysis of Carbonaceous Components in PM2.5 in a Typical Industrial City

Coordination Relationship of Carbon Emissions and Air Pollutants under Governance Measures in a Typical Industrial City in China

Coordinating and controlling carbon and atmospheric pollutant emissions in industrial cities poses challenges, making it difficult to formulate effective environmental governance strategies in China. This study used the Community Multiscale Air Quality (CMAQ) and Long-range Energy Alternatives Planning (LEAP) models, with a typical industrial city in the Sichuan Basin as the case study. Five emission reduction scenarios, one integration scenario, and one baseline scenario were set to quantitatively analyze the synergistic effect between carbon emissions and atmospheric pollutant emissions. The results indicate a high synergy between sulfur dioxide and greenhouse gases. For every one-point decrease in the Air Quality Composite Index (AQCI), the Industrial Restructuring Scenario (IR), Other Source Management Scenario (OSM), Transportation Energy Efficiency Improvement Scenario (TEEI), Industrial Energy Efficiency Improvement Scenario (IEEI), and Transportation Restructuring (TR) scenarios would require a reduction in carbon emissions by 56,492.79 kilotons, 39,850.45 kilotons, 34,027.5 kilotons, 22,356.58 kilotons, and 3243.33 kilotons, respectively. The results indicate that governance measures, such as improving transportation structure and upgrading industrial technologies, provide stronger support for simultaneous carbon emissions reductions and air quality improvement.

A comprehensive attribution analysis of PM2.5 in typical industrial cities during the winter of 2016–2018: Effect of meteorology and emission reduction

The frequent occurrence of air pollution in winter has aroused widespread concern. Identifying the detailed source composition of PM2.5 and assessing the reduction effects of different emission sources are crucial steps in improving pollution levels. In this study, we conducted a comprehensive evaluation of emission source reductions, encompassing ten local and ten regional sources. Furthermore, we analyzed the influence of meteorological changes on the abatement of PM2.5 in Tangshan, Shijiazhuang, Xingtai, and Handan during the winter period from 2016 to 2018. Our findings indicate that, in comparison to the winter of 2016, there were significant decreases in the average concentrations of PM2.5 during the winter of 2017. These decreases were attributed to favorable meteorological conditions and emission reductions. However, during the winter of 2018, there was a rebound in PM2.5 concentrations for all four cities. This rebound was primarily caused by adverse meteorological diffusion conditions. Throughout the entire research period spanning from the winter of 2016 to 2018, emission reduction played a significant role in PM2.5 abatement, contributing to 68% in Tangshan, 87% in Shijiazhuang, 93% in Xingtai, and 96% in Handan, respectively. The source apportionment analysis revealed that industrial and residential sources were the dominant contributors to PM2.5 concentrations in the cities. These findings not only confirm the effectiveness of existing industrial and residential pollution control policies but also highlight the imperative need for implementing non-point source control and joint control measures for regional elevated sources in the future.