On the local anthropogenic source diversities and transboundary transport for urban agglomeration ozone mitigation

We investigated water-soluble ions (WSIs) of aerosol samples collected from 2016 to 2017 in Lanzhou, a typical semi-arid and chemical-industrialized city in Northwest China. WSIs concentration was higher in the heating period (35.68 ± 19.17 μg/m3) and lower in the non-heating period (12.45 ± 4.21 μg/m3). NO3−, SO42−, NH4+ and Ca2+ were dominant WSIs. The concentration of SO42− has decreased in recent years, while the NO3− level was increasing. WSIs concentration was affected by meteorological factors. The sulfur oxidation and nitrogen oxidation ratios (SOR and NOR) exceeded 0.1, inferring the vital contribution of secondary transformation. Meanwhile higher O3 concentration and temperature promoted the homogeneous reaction of SO2. Lower temperature and high relative humidity (RH) were more suitable for heterogeneous reactions of NO2. Three-phase cluster analysis illustrated that the anthropogenic source ions and natural source ions were dominant WSIs during the heating and non-heating periods, respectively. The backward trajectory analysis and the potential source contribution function model indicated that Lanzhou was strongly influenced by the Hexi Corridor, northeastern Qinghai–Tibetan Plateau, northern Qinghai province, Inner Mongolia Plateau and its surrounding cities. This research will improve our understanding of the air quality and pollutant sources in the industrial environment.

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Mercury Speciation in Various Coals Based on Sequential Chemical Extraction and Thermal Analysis Methods

Energies ◽

10.3390/en14092361 ◽

2021 ◽

Vol 14 (9) ◽

pp. 2361

Author(s):

Yinjiao Su ◽

Xuan Liu ◽

Yang Teng ◽

Kai Zhang

Keyword(s):

Thermal Stability ◽

Coal Combustion ◽

Decomposition Methods ◽

Chemical Extraction ◽

Anthropogenic Source ◽

Coal Rank ◽

Coal Pyrolysis ◽

Mercury Emissions ◽

Sequential Chemical Extraction ◽

Removal Technology

Coal combustion is an anthropogenic source of mercury (Hg) emissions to the atmosphere. The strong toxicity and bioaccumulation potential have prompted attention to the control of mercury emissions. Pyrolysis has been regarded as an efficient Hg removal technology before coal combustion and other utilization processes. In this work, the Hg speciation in coal and its thermal stability were investigated by combined sequential chemical extraction and temperature programmed decomposition methods; the effect of coal rank on Hg speciation distribution and Hg release characteristics were clarified based on the weight loss of coal; the amount of Hg released; and the emission of sulfur-containing gases during coal pyrolysis. Five species of mercury were determined in this study: exchangeable Hg (F1), carbonate + sulfate + oxide bound Hg (F2), silicate + aluminosilicate bound Hg (F3), sulfide bound Hg (F4), and residual Hg (F5), which are quite distinct in different rank coals. Generally, Hg enriched in carbonates, sulfates, and oxides might migrate to sulfides with the transformation of minerals during the coalification process. The order of thermal stability of different Hg speciation in coal is F1 < F5 < F2 < F4 < F3. Meanwhile, the release of Hg is accompanied with sulfur gases during coal pyrolysis, which is heavily dependent on the coal rank.

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Analysis on the Spatial Structure of Tourism Economy of Chengdu Chongqing Urban Agglomeration

2020 The 4th International Conference on E-commerce, E-Business and E-Government ◽

10.1145/3409929.3416791 ◽

2020 ◽

Author(s):

FENG XIAOBING

Keyword(s):

Spatial Structure ◽

Urban Agglomeration ◽

Tourism Economy

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The Spatio-Temporal Analysis of Urban-Rural Coordinated Development and Its Driving Forces in Yangtze River Delta

Land ◽

10.3390/land10050495 ◽

2021 ◽

Vol 10 (5) ◽

pp. 495

Author(s):

Daizhong Tang ◽

Mengyuan Mao ◽

Jiangang Shi ◽

Wenwen Hua

Keyword(s):

Influencing Factors ◽

Yangtze River ◽

Driving Forces ◽

Yangtze River Delta ◽

River Delta ◽

Urban Agglomeration ◽

System Level ◽

Actual State ◽

Coordinated Development ◽

Urban Rural

This paper conducts an analytical study on the urban-rural coordinated development (URCD) in the Yangtze River Delta urban agglomeration (YRDUA), and uses data from 2000–2015 of 27 central cities to study the spatial and temporal evolution patterns of URCD and to discover the influencing factors and driving forces behind it through PCA, ESDA and spatial regression models. It reveals that URCD of the YRDUA shows an obvious club convergence phenomenon during the research duration. The regions with high-level URCD gather mainly in the central part of the urban agglomeration, while the remaining regions mostly have low-level URCD, reflecting the regional aggregation phenomenon of spatial divergence. At the same time, we split URCD into efficiency and equity: urban-rural efficient development (URED) also exhibits similar spatiotemporal evolution patterns, but the patterns of urban-rural balanced development (URBD) show some variability. Finally, by analyzing the driving forces in major years during 2000–2015, it can be concluded that: (i) In recent years, influencing factors such as government financial input and consumption no longer play the main driving role. (ii) Influencing factors such as industrialization degree, fixed asset investment and foreign investment even limit URCD in some years. The above results also show that the government should redesign at the system level to give full play to the contributing factors depending on the actual state of development in different regions and promote the coordinated development of urban and rural areas. The results of this study show that the idea of measuring URCD from two dimensions of efficiency and equity is practical and feasible, and the spatial econometric model can reveal the spatial distribution heterogeneity and time evolution characteristics of regional development, which can provide useful insights for urban-rural integration development of other countries and regions.

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The Gradient Effect on the Relationship between the Underlying Factor and Land Surface Temperature in Large Urbanized Region

Land ◽

10.3390/land10010020 ◽

2020 ◽

Vol 10 (1) ◽

pp. 20

Author(s):

Yixu Wang ◽

Mingxue Xu ◽

Jun Li ◽

Nan Jiang ◽

Dongchuan Wang ◽

...

Keyword(s):

Surface Temperature ◽

Land Surface Temperature ◽

Land Surface ◽

Landscape Planning ◽

Potential Gradient ◽

Surface Characteristics ◽

Ordinary Least Squares ◽

Urban Agglomeration ◽

Spatial Gradient ◽

Gradient Effect

Although research relating to the urban heat island (UHI) phenomenon has been significantly increasing in recent years, there is still a lack of a continuous and clear recognition of the potential gradient effect on the UHI—landscape relationship within large urbanized regions. In this study, we chose the Beijing-Tianjin-Hebei (BTH) region, which is a large scaled urban agglomeration in China, as the case study area. We examined the causal relationship between the LST variation and underlying surface characteristics using multi-temporal land cover and summer average land surface temperature (LST) data as the analyzed variables. This study then further discussed the modeling performance when quantifying their relationship from a spatial gradient perspective (the grid size ranged from 6 to 24 km), by comparing the ordinary least squares (OLS) and geographically weighted regression (GWR) methods. The results indicate that: (1) both the OLS and GWR analysis confirmed that the composition of built-up land contributes as an essential factor that is responsible for the UHI phenomenon in a large urban agglomeration region; (2) for the OLS, the modeled relationship between the LST and its drive factor showed a significant spatial gradient effect, changing with different spatial analysis grids; and, (3) in contrast, using the GWR model revealed a considerably robust and better performance for accommodating the spatial non-stationarity with a lower scale dependence than that of the OLS model. This study highlights the significant spatial heterogeneity that is related to the UHI effect in large-extent urban agglomeration areas, and it suggests that the potential gradient effect and uncertainty induced by different spatial scale and methodology usage should be considered when modeling the UHI effect with urbanization. This would supplement current UHI study and be beneficial for deepening the cognition and enlightenment of landscape planning for UHI regulation.

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Planning of a Cargo Control Post within an Urban Agglomeration

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/666/5/052078 ◽

2021 ◽

Vol 666 (5) ◽

pp. 052078

Author(s):

A Shevtsova ◽

A N Novikov ◽

A V Stetsenko ◽

V V Panyushktn

Keyword(s):

Urban Agglomeration ◽

Control Post

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Spatial and temporal variation Trend Analysis of vegetation cover in Urban agglomeration of Pearl River Delta from 2000 to 2015

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/615/1/012028 ◽

2020 ◽

Vol 615 ◽

pp. 012028

Author(s):

Dong Zhang ◽

Fengzhi Wu ◽

Yanzhuo Fang ◽

Ni Lu

Keyword(s):

Temporal Variation ◽

Trend Analysis ◽

Vegetation Cover ◽

Pearl River Delta ◽

River Delta ◽

Urban Agglomeration ◽

Spatial And Temporal Variation ◽

Pearl River ◽

Variation Trend

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Assessment of heavy metal pollution in soil and bottom sediment of Upper Egypt: comparison study

Bulletin of the National Research Centre ◽

10.1186/s42269-019-0233-4 ◽

2019 ◽

Vol 43 (1) ◽

Author(s):

Esmat Ahmed Abou El-Anwar

Keyword(s):

Heavy Metals ◽

Ecological Risk ◽

Nitrogen Fertilizer ◽

Toxic Waste ◽

Anthropogenic Source ◽

Pollution Indices ◽

Upper Egypt ◽

Pulp Paper ◽

Heavy Metals Pollution ◽

Cultivated Soils

Abstract Background Aswan and Luxor Governorates are characterized by multifaceted activities such as cement, chemicals, fertilizers, detergents, nitrogen fertilizer factory at Aswan, the sugar and diary factory at Kom Ombo, and several other factories such as the sugar, pulp, paper, ferrosilicon, and phosphate factories at Edfu, urbanization and agriculture. In addition, there is a main sewage station which is used for irrigation of many crops. Assessing the pollution of soil and sediment with some heavy metals in these areas is the main aim of the current work. Results The average heavy metals content in the studied cultivated soils and Nile sediments are above the acceptable levels. Generally, Nile sediments and cultivated soils at Aswan and Luxor were unpolluted to moderately polluted with heavy metals. Pollution indices indicated that the studied Nile sediments were at considerably ecological risk from Cd (Er = 138.89) and Zn (Er = 140.52). In contrast, the cultivated soil was at very high ecological risk from Cd (Er = 295.24). Conclusions The current research revealed that the soil and sediments in the Upper Egypt are less polluted than Lower Egypt. Thus, the concentrations of toxic elements are increased from south to north direction in Egypt along the Nile River. The sources of the toxic metals may possibly be natural or anthropogenic in the studied area. The anthropogenic source is resulting from paper, pulp, ferrosilicon factories, and phosphate mining at Edfu. In addition, there are some polluting industries such as sand quarry, shale mining, and the nitrogen fertilizer factory at Aswan. On the other hand, the natural sources of toxic waste are the drains during the seasonal flash floods.

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