Search Results (215)

This pilot study investigated an automated pilot plant for removing microplastics (MPs) from industrial wastewater that are generated during packaging production. MP removal is based on organosilane-induced agglomeration-fixation (clump & skim technology) followed by separation. The wastewater had high MP loads (1725 ± 377 mg/L; 673 ± 183 million particles/L) and an average COD of 7570 ± 1339 mg/L. Over 25 continuous test runs, the system achieved consistent performance, removing an average of 97.4% of MPs by mass and 99.1% by particle count, while reducing the COD by 78.8%. Projected over a year, this equates to preventing 1.7 tons of MPs and 6 tons of COD from entering the sewage system. Turbidity and photometric TSS measurements proved useful for process control. The approach supports water reuse—with water savings up to 80%—and allows recovery of agglomerates for recycling and reuse. Targeting pollutant removal upstream at the source provides multiple financial and environmental benefits, including lower overall energy demands, higher removal efficiencies, and process water reuse. This provides financial and environmental incentives for industries to implement sustainable solutions for pollutants and microplastic removal. Full article

The Yangtze River Delta urban agglomeration, characterized by high population density, an advanced transportation system, and a concentration of industrial activity, is one of the regions severely affected by O₃ pollution in central and eastern China. Using data collected from 251 monitoring stations between 2015 and 2025, this paper analyzed the spatio-temporal variation of 8 h O₃ concentrations and instances of exceedance. On the basis of exploring the influence of meteorological factors on regional 8 h O₃ concentration, the potential source contribution areas of pollutants under the exceedance condition were investigated using the HYSPLIT model. The results indicate a rapid increase in the 8 h O₃ concentration at a rate of 0.91 ± 0.98 μg·m⁻³·a⁻¹, with the average number of days exceeding concentration standards reaching 41.05 in the Yangtze River Delta urban agglomeration. Spatially, the 8 h O₃ concentrations were higher in coastal areas and lower in inland regions, as well as elevated in plains compared to hilly terrains. This distribution was significantly distinct from the concentration growth trend characterized by higher levels in the northwest and lower levels in the southeast. Furthermore, it diverged from the spatial characteristics where exceedances primarily occurred in the heavily industrialized northeastern region and the lightly industrialized central region, indicating that the growth and exceedance of 8 h O₃ concentrations were influenced by disparate factors. Local human activities have intensified the emissions of ozone precursor substances, which could be the key driving factor for the significant increase in regional 8 h O₃ concentrations. In the context of high temperatures and low humidity, this has contributed to elevated levels of 8 h O₃ concentrations. When wind speeds were below 2.5 m·s⁻¹, the proportion of 8 h O₃ concentrations exceeding the standards was nearly 0 under almost calm wind conditions, and it showed an increasing trend with rising wind speeds, indicating that the potential precursor sources that caused high O₃ concentrations originated occasionally from inland regions, with very limited presence within the study area. This observation implies that the main cause of exceedances was the transport effect of pollution from outside the region. Therefore, it is recommended that the Yangtze River Delta urban agglomeration adopt economic and technological compensation mechanisms within and between regions to reduce the emission intensity of precursor substances in potential source areas, thereby effectively controlling O₃ concentrations and improving public living conditions and quality of life. Full article

Achieving the synergistic effect of pollution reduction and carbon mitigation (PRCM) is a core pathway for promoting green and low-carbon transition and realizing the “dual carbon” goals, as well as a crucial mechanism for coordinating ecological environment governance with climate action. Based on panel data from three major urban agglomerations (Beijing–Tianjin–Hebei, Yangtze River Delta, and Pearl River Delta) between 2008 and 2019, this study employs network centrality and structural holes to characterize urban network positions (UNP), and systematically investigates the impact mechanisms and spatial heterogeneity of urban network positions on PRCM synergy using a dual fixed-effects model. The findings reveal that (1) urban network positions exert significant inhibitory effects on the overall synergy of PRCM, meaning higher centrality and structural hole advantages hinder synergistic progress. This conclusion remains valid after robustness checks and endogeneity tests using instrumental variables. (2) Heterogeneity analysis shows the inhibitory effects are particularly pronounced in Type I large cities and southern urban agglomerations, attributable to environmental governance path dependence caused by complex industrial structures in metropolises and compounded pressures from export-oriented economies undertaking industrial transfers in southern regions. Northern cities demonstrate stronger environmental resilience due to first-mover advantages in heavy industry transformation. (3) Mechanism testing reveals that cities occupying advantageous network positions tend to reduce environmental regulation stringency and research and development investment levels. Conversely, cities at the network periphery demonstrate late-mover advantages by embedding environmental regulations and building stable technological cooperation partnerships. This study provides a theoretical foundation for optimizing urban network spatial configurations and implementing differentiated environmental governance policies. It emphasizes the necessity of holistically integrating network effects with ecological effects during new-type urbanization, advocating for the establishment of a multi-scale coordinated environmental governance system. Full article

Since China’s reform and opening up over 40 years ago, rapid urbanization has led to significant progress, but also severe air pollution. Understanding how air pollution affects the sustainable development of different city types is crucial for formulating targeted mitigation strategies. Thus, we propose the hypothesis that air pollution affects urban sustainable development through the synergistic interactions of population, industry, space, and society. To test this hypothesis, we construct a simultaneous equation system incorporating pollution, population, industry, spatial, and social factors, utilizing the Three-Stage Least Squares method for estimation. The robustness of our results is rigorously verified. Additionally, to explore deeper mechanisms, we perform a multi-dimensional heterogeneity analysis. Our results indicate that: (1) Air pollution negatively impacts urban sustainable development by reducing urban population size, with a coefficient of −0.950; (2) Air pollution hinders urban sustainable development by reducing manufacturing agglomeration, with a coefficient of −0.962; (3) Air pollution induces disordered urban spatial expansion, undermining sustainable development, with a coefficient of 2.596; and (4) Air pollution leads to stricter environmental rules, with a coefficient of 17.428, and these rules boost urban sustainability in the long term. Heterogeneity analysis further reveals that the intensity, direction, and statistical significance of air pollution’s effects vary across cities with different regional characteristics, pollution levels, population scales, industrial structures, spatial patterns, and regulatory intensities. Full article

In recent years, with the rapid socioeconomic development of Wuxi City, the frequent occurrence of severe air pollution events has attracted widespread attention from both the local government and the public. Based on the real-time monitoring data of criteria pollutants and GDAS (Global Data Assimilation System) reanalysis data, the spatiotemporal variation patterns, meteorological influences, and potential sources of major air pollutants in Wuxi across different seasons during 2019 (pre-COVID-19) and 2023 (post-COVID-19 restrictions) are investigated using the Pearson correlation coefficient, potential source contribution function (PSCF), and concentration-weighted trajectory (CWT) models. The results demonstrate that the annual mean PM_2.5 concentration in Wuxi decreased significantly from 39.6 μg/m³ in 2019 to 29.3 μg/m³ in 2023, whereas the annual mean 8h O₃ concentration remained persistently elevated, with comparable levels of 104.6 μg/m³ and 105.0 μg/m³ in 2019 and 2023, respectively. The O₃ and particulate matter (PM) remain the most prominent air pollutants in Wuxi’s ambient air quality. The hourly mass concentrations of criteria pollutants, except O₃, exhibited characteristic bimodal distributions, with peak concentrations occurring post-rush hour during morning and evening commute periods. In contrast, O₃ displayed a distinct unimodal diurnal pattern, peaking between 15:00 and 16:00 local time. The spatial distribution patterns revealed significantly elevated concentrations of all monitored species, excluding O₃, in the central urban zone, compared to the northern Taihu Lake region. The statistical analysis revealed significant correlations among PM concentrations and other air pollutants. Additionally, meteorological parameters exerted substantial influences on pollutant concentrations. The PSCF and CWT analyses revealed distinct seasonal variations in the potential source regions of atmospheric pollutants in Wuxi. In spring, the Suzhou–Wuxi–Changzhou metropolitan cluster and northern Zhejiang Province were identified as significant contributors to PM_2.5 and O₃ pollution in Wuxi. The potential source regions of O₃ are predominantly distributed across the Taihu Lake-rim cities during summer, while the eastern urban agglomeration adjacent to Wuxi serves as major potential source areas for O₃ in autumn. In winter, the prevailing northerly winds facilitate southward PM_2.5 transport from central-northern Jiangsu, characterized by high emissions (e.g., industrial activities), identifying this region as a key potential source contribution area for Wuxi’s aerosol pollution. The current air pollution status in Wuxi City underscores the imperative for implementing more stringent and efficacious intervention strategies to ameliorate air quality. Full article

As an economically active region, the Guangdong–Hong Kong–Macao Greater Bay Area (GBA) faces dual challenges of carbon and air pollution reduction. Existing studies predominantly focus on single pollutants or engineering pathways, lacking systematic analyses of multi-scale synergistic effects. This study investigates the spatiotemporal distributions, driving factors, and synergistic effects of CO₂ and volatile organic compounds (VOCs) at the multi-scale of urban agglomerations, cities, and industries, using global Moran’s index, standard deviational ellipse, logarithmic mean divisa index decomposition model, and Tapio decoupling model. The results show that the average annual growth rate of CO₂ (7.4%) was significantly higher than that of VOCs (4.5%) from 2000 to 2020, and the industrial sector contributed more than 70% of CO₂ and VOC emissions, with the center of gravity of emissions migrating to Dongguan. Industrial energy intensity improvement emerged as the primary mitigation driver, with Guangzhou and Shenzhen demonstrating the highest contribution rates. Additionally, CO₂ and VOC reduction show two-way positive synergy, and the path of “energy intensity enhancement–carbon and pollution reduction” in the industrial sector is effective. Notably, the number of strong decouplings of the economy from CO₂ (11 times) is much higher than the number of strong decouplings of VOCs (3 times), suggesting that the synergy between VOC management and economic transformation needs to be strengthened. This study provides scientific foundations for phased co-reduction targets and energy–industrial structure optimization, proposing regional joint prevention and control policy frameworks. Full article

Green technology innovation can effectively reduce the problem of pollution transfer in air pollution-intensive industries like thermal power and realize the green development of air pollution-intensive industries like thermal power. Based on green technology innovation, this paper analyzes the spatial–temporal characteristics of fog–haze in 31 provinces and municipalities. Taking the panel data of 31 provinces, municipalities, and autonomous regions from 2000 to 2017 as samples, this paper adopts the panel threshold regression method to examine the relationship between green technology innovation and fog–haze pollution in the transfer of air pollution-intensive industries like thermal power. The study found the following: China’s haze outbreak and the subsequent increasingly serious reasons for the implementation of weight detection haze policy seriously misled the haze prevention and control work, simple disorganized management aggravated the degree of haze pollution, and layer by layer, management methods caused the huge increase in secondary particulate matter; haze pollution aggregation occurs in the area of environmental self-purification capacity in the low air pollution-intensive industrial agglomeration to affect the atmospheric environment, a significant increase in the neighbouring industrial pollution agglomeration in resource-rich provinces; green technology innovation above the threshold has a significant inhibitory effect on the industrial transfer of haze pollution, and so on. There is a need for the scientific planning of pollution industry transfer to undertake the development of the place, the effective transfer of Beijing–Tianjin–Hebei haze pollution and other areas of air pollution-intensive industries, the development of targeted green technology innovation to strengthen policies, the scientific management of haze pollution, and the contribution of the scientific management of haze pollution in China. Full article

Financial agglomeration and green technology innovation are important measures to reduce carbon emissions and promote the development of a green economy. Based on the panel data of 30 provinces and cities in China from 2011 to 2020, this paper uses the locational entropy method and the carbon emission coefficient measurement method provided in the IPCC inventory guide to establish a spatial econometric model to explore the specific impact of financial agglomeration and green technology innovation on carbon emission. The results show that (1) both financial agglomeration and green technology innovation will reduce carbon emissions; (2) when considering the spatial effect, financial agglomeration and green technology innovation will effectively reduce carbon emissions; (3) the influence of financial agglomeration and green technology innovation on carbon emissions has regional heterogeneity. Only green technology innovation can significantly reduce carbon emissions in the eastern region. Financial agglomeration and green technology innovation in the central region can significantly reduce carbon emissions. Financial agglomeration in the western region can significantly reduce carbon emissions, but green technology innovation will lead to an increase in carbon emissions. This paper provides useful suggestions for optimizing the financial industry’s structure, improving the level of green technology, and alleviating environmental pollution. Full article

Mercury, a global pollutant with high biotoxicity, is widely distributed in soils, water bodies, and the atmosphere. Anthropogenic activities such as industrial emissions and coal combustion release large quantities of mercury into the environment, posing health risks to human populations. Strict implementation of the Minamata Convention and innovative remediation technologies can mitigate escalating environmental and public health risks. This study investigated the spatiotemporal dynamics of mercury in soils and atmosphere across four spatial scales (central city, county, township, and village) within the Changchun urban agglomeration, China. During spring, summer, and autumn of 2023, surface soil and atmospheric mercury concentrations (at 0 cm and 100 cm) were measured using LUMEX RA-915+ at 361 sites. Soil mercury exhibited seasonal variability, with a mean concentration of 46.2 µg/kg, showing peak values in spring and troughs in summer; concentrations decreased by 29.40% from spring to summer, followed by a 27.85% rebound in autumn. Spatially, soil mercury concentrations exhibited a core–periphery decreasing gradient (central city > county > township > village). Average concentrations at county, township, and village levels were 9.92%, 35.07%, and 42.11% lower, respectively, than those in the central city. Atmospheric mercury displayed seasonal variations; mean concentrations at 0 cm and 100 cm heights were 6.13 ng/m³ and 6.75 ng/m³, respectively, both peaking in summer. At 0 cm, summer concentrations increased by 35.61% compared to spring, then declined by 35.96% in autumn; at 100 cm, summer concentrations rose by 49.39% from spring and decreased by 31.08% in autumn. Atmospheric mercury at both heights decreased from the central city to the peripheries, with reductions of approximately 40% at 0 cm and 37–39% at 100 cm. Atmospheric mercury dynamics were significantly correlated with meteorological parameters such as temperature and humidity. Spatial autocorrelation analysis revealed scale-dependent clustering patterns: soil mercury Moran’s I ranked central city > county > village > township, while atmospheric mercury followed township > village > county > central city. Structural equation modeling demonstrated that different spatial scales had a significant negative effect on soil mercury concentrations, atmospheric mercury concentrations at 0 cm and 100 cm, and mercury and its compounds emissions. Organic matter content had a significant positive effect on soil mercury content. Temperature and humidity positively influenced near-surface atmospheric mercury. This multi-scale approach elucidates urban agglomeration mercury dynamics, highlighting core–periphery pollution gradients and seasonal patterns, thereby providing empirical evidence for regional mercury transport studies and providing a scientific foundation for future heavy metal management strategies. Full article

Microplastics (MPs) that are ubiquitous in aquatic environments and industrial wastewater streams have been identified as key hotspots of MP contamination. It is significantly more effective to remove MPs at these points before they enter municipal wastewater streams. This study is an environmental assessment of a novel pilot plant for the removal of MPs and the chemical oxygen demand (COD) from wastewater with a high MP contamination from a plastics manufacturer in Germany. MP removal is based on physical–chemical agglomeration–fixation by organosilanes. Formed agglomerates are separated using a belt filter. The COD is removed by an adsorption process. The resulting MP removal was 98.0 ± 1.1% by mass and 99.9987 ± 0.0007% by particle count, while the COD was reduced by 96 ± 2.7%. The system’s sustainability is evaluated using the Life Cycle Assessment methodology, evaluating system construction, operation, and end-of-life considerations. The current pilot plant is also compared to an optimized circular and sustainable upgrade, where drivers of environmental burdens are eliminated and collected MPs are reused. Significant reductions in environmental impact categories are achieved and the global warming potential is reduced by 96%. This study provides a sustainability assessment of a novel technology and circular solution to remove MPs from highly polluted industrial wastewater. Full article

In China, with the increasing emphasis on the concept of green sustainable development, polluting industries characterized by pollution and high energy consumption are facing unprecedented challenges. The development of the intermediate demand-type characteristics of polluting industries should be more reasonably laid out and regulated. In this paper, environmental regulation and environmental quality are introduced into the new economic geography model. On the basis of theoretical analysis, the IV regression method was used to study the interaction between polluting industry agglomeration, environmental regulation, and their effects on urban air quality with key cities as research objects. The results show that an increase in the agglomeration of polluting industries leads to significant deterioration in urban air quality and that this effect is linear, whereas an increase in the intensity of environmental regulation significantly dampens this effect. Each 1% increase in the intensity of environmental regulation results in a 1.17% reduction in air pollution. Therefore, to effectively protect the environment, the development of polluting industries should be relatively decentralized. Additionally, city governments should fully consider their urban eco-geographical characteristics, directly reduce and indirectly inhibit the degree of agglomeration of polluting industries and simultaneously strengthen the intensity of environmental regulation. Full article

The increasing demand for freshwater resources, coupled with industrial pollution, necessitates improved water treatment technologies. This study investigates the potential of quartz-based filtration systems enhanced with hydrophilic nanoparticles for efficient oil-water separation. The quartz material, abundant and cost-effective, was processed and modified through sequential coatings to enhance its hydrophilicity and separation efficiency. Comprehensive characterization techniques, including SEM, XRD, and Raman spectroscopy, were employed to evaluate surface morphology, chemical composition, and structural integrity at different stages of coating. The findings demonstrated that the first coating achieved the most uniform nanoparticle distribution, significantly improving hydrophilicity and separation efficiency, reducing oil content in filtrates to 17.3 mg/L. Subsequent coatings resulted in agglomeration and pore clogging, leading to diminished performance. Validation through mathematical models corroborated experimental observations, confirming the first coating’s superior balance of nanoparticle integration, permeability, and separation efficiency. This research highlights the potential of surface-engineered quartz as a scalable, cost-effective solution for sustainable water reuse. Future work will focus on optimizing coating techniques, scaling up, and integrating the system with complementary technologies to enhance water treatment processes. Full article

Over the past 70 years since the founding of the People’s Republic of China, urban development has achieved remarkable progress but also encountered severe atmospheric pollution, which has become a significant obstacle to high-quality urban development. Understanding the interaction mechanisms between urban development and atmospheric pollution is thus crucial for promoting sustainable urban construction. This paper explores these mechanisms by analyzing the interplay between urban population, industry, space, social development, and pollution through a theoretical framework. Using a simultaneous equations model and the Three-Stage Least Squares (3SLS) method, it examines these relationships and further investigates threshold effects. The findings reveal a nonlinear relationship with significant thresholds: (1) High levels of PM_2.5, population size, and industrial agglomeration can shift from exacerbating pollution to enabling governance, though excessive thresholds reverse this trend. (2) PM_2.5 mediates the impact of spatial sprawl, environmental regulation, and population dynamics, oscillating between governance and pollution effects. (3) Industrial agglomeration and spatial sprawl show variable impacts on pollution mitigation depending on pollution intensity and urban thresholds. These findings provide critical insights into the intricate dynamics between urban development and atmospheric pollution, emphasizing the importance of adopting differentiated strategies based on specific urban thresholds. Ultimately, this research contributes to the broader goal of harmonizing economic growth, social development, and environmental sustainability in urban areas, serving as a valuable reference for cities worldwide facing similar challenges. Full article

Water pollution caused by emerging contaminants is increasing due to rising urbanization, industrialization, and agriculture production; therefore, new materials with high efficiency for wastewater decontamination are needed. A perovskite material based on 1% Ag-doped LaMnO₃ synthesized through a sol–gel technique was combined with PVP in a 1:10 (w/w) ratio and subjected to different temperature and microwave conditions at various time intervals. The composite materials were obtained as thin films (S1, S2) or powders (S3) and were analyzed by modern techniques. The SEM analysis showed strongly agglomerated, asymmetric formations for the S1, S2 materials; as for the S3 composite, irregularly shaped grains of perovskite were deposited on the polymer surface. Small, round formations across the surface, mainly organized as clusters with conic/square-shaped particles and observed asperity on top, were highlighted by AFM images. The XRD spectra confirmed the presence of both the perovskite and PVP phases, and the crystallite size of the materials was determined to be in the range of 33–43 nm. The structural analyses, FT-IR, and Raman spectroscopy proved the interactions between the perovskite and the polymer, which led to novel composite materials. The different methods used for the synthesis of the new materials influenced their features and behavior. Moreover, the composites were successfully tested for methyl orange (MO) elimination from an acidic aqueous solution in dark conditions, with fast and complete (>95%) MO degradation at pH = 2. Full article

Venture capital is vital for developing capital markets and the low-carbon transformation of the economy. We used panel data from 27 cities in the Yangtze River Delta urban agglomeration from 2011 to 2022 to investigate how the scale and structure of venture capital influence the intensity of urban carbon emissions using spatial econometric models. We show that an increase in the scale of venture capital can inhibit the increase in the intensity of urban carbon emissions, and the effect is more pronounced in cities with higher pollution and better geographical location. Heterogeneity exists in the carbon-reduction effects of venture capital across industries. The direct carbon reduction effect of venture capital flowing to mid- and low-end industries is stronger and more prominent in cities with higher pollution and less favourable geographical locations. The long-term carbon reduction effect of venture capital flowing to high-end industries is stronger. The mediating effect of technological innovation is prominent, while the effect of industrial structure upgrade is not prominent. The enterprises’ willingness and ability to engage in green transformation acts as a positive moderator, whereas the positive moderating effect of the government in that respect is insufficient. This study clarifies the mechanism of venture capital on urban carbon emissions and offers valuable insights for optimising the structure and system of venture capital. Full article