International Journal of Environmental Research and Public Health

Research

15 pages, 2354 KiB

Open AccessArticle

Spatial Distribution, Contamination Assessment and Origin of Soil Heavy Metals in the Danjiangkou Reservoir, China

by Qiuyao Dong, Chao Song, Dongxue Yang, Yuqing Zhao and Mingjiang Yan

Int. J. Environ. Res. Public Health 2023, 20(4), 3443; https://doi.org/10.3390/ijerph20043443 - 15 Feb 2023

Cited by 7 | Viewed by 2060

Soil heavy metal contamination is crucial due to menacing food safety and mortal health. At present, with the fast advancement of urbanization and industrialization, heavy metals are increasingly released into the soil by anthropogenic activities, and the soil ecosystem contamination around the Danjiangkou [...] Read more.

Soil heavy metal contamination is crucial due to menacing food safety and mortal health. At present, with the fast advancement of urbanization and industrialization, heavy metals are increasingly released into the soil by anthropogenic activities, and the soil ecosystem contamination around the Danjiangkou Reservoir is directly associated with water quality security of the reservoir. In this paper, using 639 soil samples from the Danjiangkou Reservoir, Henan Province, China, we studied a variety of space distribution characteristics of heavy metals in soil. Geographic information system analysis (GIS), geo-accumulation index (I_geo), contamination factor (CF), principal component analysis (PCA) model, and positive matrix factorization (PMF) model were used together to recognize and quantify the distribution, contamination, and origin of heavy metals. We uncovered an exceptional variety of heavy metal concentrations among the tested soils: the mean arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), manganese (Mn), nickel (Ni), zinc (Zn), lead (Pb) and mercury (Hg) concentrations (14.54, 0.21, 18.69, 81.69, 898.42, 39.37, 79.50, 28.11, 0.04 mg/kg, respectively, in the topsoil (0–20 cm depth)), all exceed their background values. The mean I_geo value and CF values of these trace elements are both in descending order: Cd > Co > Mn > Ni > Pb > Zn > Cr > As > Hg. Cd was the highest contributor to the assessment of heavy metal pollution, with an average I_geo value over three, indicating that the study area is modestly contaminated by Cd. The PCA analysis and PMF model revealed three potential sources, including natural sources (PC1) for Cr, Co, Mn and Ni; agricultural sources (PC2) for Cd, Zn and Hg; and industrial emissions and transportation sources (PC3) for Pb. This study displays a map of heavy metal contamination in the eastern area topsoil of the Danjiangkou Reservoir, showing the most severe pollutant is Cd, which poses a threat to the water quality security of Danjiangkou Reservoir and provides a significant source identification for future contamination control. Full article

(This article belongs to the Special Issue Sources, Migration and Transformation Processes of Pollutants in the Terrestrial Environment)

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19 pages, 9828 KiB

Open AccessArticle

Effect of Authigenic Chlorite on the Pore Structure of Tight Clastic Reservoir in Songliao Basin

by Yangchen Zhang, Xiyu Qu, Changsheng Miao, Jianfeng Zhu, Wen Xu and Weiming Wang

Int. J. Environ. Res. Public Health 2023, 20(2), 1406; https://doi.org/10.3390/ijerph20021406 - 12 Jan 2023

Cited by 2 | Viewed by 1426

Abstract

Authigenic chlorite is a common clay mineral in clastic rock reservoirs, and it has an important influence on the pore structure of tight clastic rock reservoirs. In this paper, the tight clastic reservoirs in the Lower Cretaceous Yingcheng Formation in the Longfengshan subsag [...] Read more.

Authigenic chlorite is a common clay mineral in clastic rock reservoirs, and it has an important influence on the pore structure of tight clastic rock reservoirs. In this paper, the tight clastic reservoirs in the Lower Cretaceous Yingcheng Formation in the Longfengshan subsag in the Changling fault depression in the Songliao Basin were investigated. Polarized light microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), high-pressure mercury injection (HPMI), and low temperature nitrogen adsorption (LTNA) were used to study the influence of authigenic chlorite on the pore structure of tight clastic reservoirs. The results show that the authigenic chlorite in the study area was mainly generated in the form of pore linings. The formation of the authigenic chlorite was mainly controlled by the parent rock type and the sedimentary microfacies in the provenance area. The hydrolysis and dissolution of the iron- and magnesium-rich intermediate-mafic magmatic rocks and the high-energy, open, weakly alkaline reducing environment in the delta-front underwater distributary channel were the key factors controlling the formation of the authigenic chlorite in the study area. The pore-lining chlorite slowed down compaction and inhibited quartz overgrowth, protecting the original pores. Moreover, there are a large number of intercrystalline pores in the chlorite, which provided channels for the flow of acidic water and thus the formation of secondary pores, playing a positive role in the physical properties of the tight clastic rock reservoirs. However, the pore-filling chlorite also blocked the pore throats, playing a negative role in the physical properties of the tight clastic rock reservoirs. The tight clastic rock reservoirs with pore-lining chlorite generally had low displacement pressures and large pore throat radii. The morphology of the nano-scale pores was mainly parallel plate-shaped slit pores. There were many primary pores and a small number of secondary pores in the reservoir. Some of the pores were connected by narrow-necked or curved sheet-like throats, and the pore structure was relatively good. A higher relative content of chlorite led to a larger nano-scale pore throat radius, a smaller specific surface area, a smoother pore surface, and stronger homogeneity. Authigenic chlorite played a positive role in the formation of the tight clastic reservoirs in the study area. Full article

(This article belongs to the Special Issue Sources, Migration and Transformation Processes of Pollutants in the Terrestrial Environment)

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48 pages, 14669 KiB

Open AccessArticle

Geochemical Responses to Natural and Anthropogenic Settings in Salt Lakes Sediments from North-Eastern Romanian Plain

by Radu Lucian Olteanu, Cristiana Radulescu, Petre Bretcan, Inga Zinicovscaia, Otilia Culicov, Konstantin Vergel, Danut Tanislav, Marius Bumbac, Cristina Mihaela Nicolescu, Ioana Daniela Dulama and Laura Monica Gorghiu

Int. J. Environ. Res. Public Health 2023, 20(2), 935; https://doi.org/10.3390/ijerph20020935 - 4 Jan 2023

Cited by 3 | Viewed by 1773

Abstract

Chemical analysis was performed on sediment core samples collected from three salt lakes, Amara Lake, Caineni Lake, and Movila Miresii Lake, located in the northeast of the Romanian Plain. The concentration of 10 main elements, 6 heavy metals (HMs), 8 rare earth elements [...] Read more.

Chemical analysis was performed on sediment core samples collected from three salt lakes, Amara Lake, Caineni Lake, and Movila Miresii Lake, located in the northeast of the Romanian Plain. The concentration of 10 main elements, 6 heavy metals (HMs), 8 rare earth elements (REEs), and 10 trace elements (TEs)—determined using neutron activation analysis (NAA)—showed variability dependent on the depth sections, lake genesis and geochemical characteristics (oxbow, fluvial harbor/liman and loess saucer type). The assessment of pollution indices (contamination factor, pollution load index, geoaccumulation index, and enrichment factor) highlighted low and moderate degrees of contamination for most of the investigated elements. Principal component analysis (PCA) extracted three principal components, explaining 70.33% (Amara Lake), 79.92% (Caineni Lake), and 71.42% (Movila Miresii Lake) of the observed variability. The principal components extracted were assigned to pedological contribution (37.42%—Amara Lake, 55.88%—Caineni Lake, and 15.31%—Movila Miresii Lake), salts depositions (due to the lack of a constant supply of freshwater and through evaporation during dry periods), atmospheric deposition (19.19%—Amara Lake, 13.80%—Caineni Lake, and 10.80%—Movila Miresii Lake), leaching from soil surface/denudation, rock weathering, and mixed anthropogenic input (e.g., agricultural runoff, wastewater discharges) (13.72%—Amara Lake, 10.24%—Caineni Lake, and 45.31%—Movila Miresii Lake). Full article

(This article belongs to the Special Issue Sources, Migration and Transformation Processes of Pollutants in the Terrestrial Environment)

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13 pages, 1389 KiB

Open AccessArticle

Health Risk Assessment of Inhalation Exposure to Airborne Particle-Bound Nitrated Polycyclic Aromatic Hydrocarbons in Urban and Suburban Areas of South China

by Peng Gao, Feng Deng, Wei-Shan Chen, Yi-Jia Zhong, Xiao-Lu Cai, Wen-Min Ma, Jian Hu and Shu-Ran Feng

Int. J. Environ. Res. Public Health 2022, 19(23), 15536; https://doi.org/10.3390/ijerph192315536 - 23 Nov 2022

Cited by 4 | Viewed by 1636

Abstract

Airborne particulates (PM_2.5 and TSP) were collected from outdoor and indoor areas at urban (Haizhu District) and suburban (Huadu District) sites from 2019 to 2020 in Guangzhou. Three nitro-polycyclic aromatic hydrocarbons (nitro-PAHs) in the airborne particulates were identified by a gas chromatograph [...] Read more.

Airborne particulates (PM_2.5 and TSP) were collected from outdoor and indoor areas at urban (Haizhu District) and suburban (Huadu District) sites from 2019 to 2020 in Guangzhou. Three nitro-polycyclic aromatic hydrocarbons (nitro-PAHs) in the airborne particulates were identified by a gas chromatograph equipped with a triple-quadrupole mass spectrometer. In the Haizhu District and Huadu District, the nitro-PAH concentrations in PM_2.5 and TSP did not show a significant decrease from winter to summer. From 2019 to 2020, the difference in the average concentration of nitro-PAHs in PM_2.5 and TSP in Guangzhou was relatively low and had no statistical significance. The diagnostic ratios of 2-nitrofluorene (2-NF)/1-nitropyrene (1-NP) in TSP are less than five, while for 2-NF/1-NP in outdoor PM_2.5 in the summer of 2019 and 2020 are more than five, which indicates that nitro-PAHs in the atmospheric PM_2.5 in Guangzhou during summer mainly originated from the secondary formation of atmospheric photochemical reactions between parent PAHs and oxidants (·OH, NO₃, and O₃). 9-Nitroanthracene (9-NT) made the most significant contribution to the total nitro-PAH concentration. The incremental lifetime cancer risks (ILCRs) of nitro-PAHs in PM_2.5 and TSP by inhalation exposure indicated low potential health risks in the urban-suburban of Guangzhou. Full article

(This article belongs to the Special Issue Sources, Migration and Transformation Processes of Pollutants in the Terrestrial Environment)

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17 pages, 45430 KiB

Open AccessArticle

Preliminary Study on the Distribution, Source, and Ecological Risk of Typical Microplastics in Karst Groundwater in Guizhou Province, China

by Xianjin An, Wei Li, Jiacheng Lan and Muhammad Adnan

Int. J. Environ. Res. Public Health 2022, 19(22), 14751; https://doi.org/10.3390/ijerph192214751 - 10 Nov 2022

Cited by 20 | Viewed by 3250

Abstract

Karst groundwater is one of the important drinking water sources in karst areas, and it has an important role in maintaining the regional ecosystem and human health. The study of microplastics (MPs) in karst groundwater has rarely been reported, and the occurrence and [...] Read more.

Karst groundwater is one of the important drinking water sources in karst areas, and it has an important role in maintaining the regional ecosystem and human health. The study of microplastics (MPs) in karst groundwater has rarely been reported, and the occurrence and migration behavior of MPs under the unique environmental conditions of karst is unclear. This study selected cave groundwater and common MPs in karst areas to explore the occurrence characteristics of MPs in groundwater to clarify the factors affecting the distribution and migration of MPs. The results showed that the abundance of MPs in karst groundwater was between 2.33 and 9.50 items·L⁻¹, with an average abundance of 4.50 items·L⁻¹. The microplastic size, type, color, and chemical composition were primarily 1~5 mm, film and fiber, color and transparent, and PS and PE, respectively. The risk characterization ratio (RCR) index results indicated that 80% of the samples were at a low ecological risk level, whereas 60% of the sampling points after concentrated rainfall in June were a medium ecological risk. The study showed that rainfall events significantly changed the abundance and migration of MPs in karst groundwater. The Pearson analysis showed a positive correlation between microplastic distribution and suspended particles (SP), total organic carbon (TOC), and water velocity (WV) in water. The study indicated that strong soil erosion in karst areas may also be one of the main sources of MPs in karst groundwater, and that karst groundwater microplastic pollution is an environmental problem that should not be ignored. Full article

(This article belongs to the Special Issue Sources, Migration and Transformation Processes of Pollutants in the Terrestrial Environment)

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16 pages, 5667 KiB

Open AccessArticle

Role of Atmospheric Temperature and Seismic Activity in Spring Water Hydrogeochemistry in Urumqi, China

by Zhihua Zhou and Jun Zhong

Int. J. Environ. Res. Public Health 2022, 19(19), 12004; https://doi.org/10.3390/ijerph191912004 - 22 Sep 2022

Cited by 2 | Viewed by 1347

Abstract

Springs offer insight into the sources and mechanisms of groundwater recharge and can be used to characterize fluid migration during earthquakes. However, few reports provide sufficient annual hydrochemical and isotopic data to compare the variation characteristics and mechanisms with both atmospheric temperature and [...] Read more.

Springs offer insight into the sources and mechanisms of groundwater recharge and can be used to characterize fluid migration during earthquakes. However, few reports provide sufficient annual hydrochemical and isotopic data to compare the variation characteristics and mechanisms with both atmospheric temperature and seismic effects. In this study, we used continuous δ²H, δ¹⁸O, and major ion data from four springs over 1 year to understand the groundwater origin, recharge sources, circulation characteristics, and coupling relationships with atmospheric temperature and earthquakes. We found that (1) atmospheric temperatures above and below 0 °C can cause significant changes in ion concentrations and water circulation depth, resulting in the mixing of fresh and old water in the aquifer, but it cannot cause changes in δ²H and δ¹⁸O. (2) Earthquakes of magnitude ≥ 4.8 within a 66 km epicentral distance can alter fault zone characteristics (e.g., permeability) and aggravate water–rock reactions, resulting in significant changes in δ²H, δ¹⁸O, and hydrochemical ion concentrations. (3) Hydrogen and oxygen isotopes are the most sensitive precursory seismic indicators. The results of this study offer a reference for the establishment of long-term hydrochemical and isotopic monitoring, with the potential for use in earthquake forecasting. Full article

(This article belongs to the Special Issue Sources, Migration and Transformation Processes of Pollutants in the Terrestrial Environment)

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14 pages, 2511 KiB

Open AccessArticle

The Effect of Rainfall on Aquatic Nitrogen and Phosphorus in a Semi-Humid Area Catchment, Northern China

by Chen-Yang Shou, Ye Tian, Bin Zhou, Xu-Jin Fu, Yun-Ji Zhu and Fu-Jun Yue

Int. J. Environ. Res. Public Health 2022, 19(17), 10962; https://doi.org/10.3390/ijerph191710962 - 2 Sep 2022

Cited by 9 | Viewed by 1837

Abstract

The impact of rainfall on water quality may be more important in semi-arid regions, where rainfall is concentrated over a couple of months. To explore the impact of rainfall changes on water quality, e.g., nitrogen (TN) and phosphorous (TP), the diversion from Luan [...] Read more.

The impact of rainfall on water quality may be more important in semi-arid regions, where rainfall is concentrated over a couple of months. To explore the impact of rainfall changes on water quality, e.g., nitrogen (TN) and phosphorous (TP), the diversion from Luan River to Tianjin Watershed in the northern semi-humid area was selected as the study area. TN and TP concentrations in rivers and the Yuqiao Reservoir during the three-year high-flow season (2019–2021) were analyzed. The response relationship and influencing factors among the watershed’s biogeochemical process, rainfall, and water quality were clarified. The results showed that rainfall in the high flow season mainly controlled the river flow. The concentration of TN and TP in the inflow rivers is regulated by rainfall/flow, while the concentration of TN and TP in the water diversion river has different variation characteristics in the water diversion period and other periods. The lowest annual concentrations of TN and TP were observed in the normal year, while the highest annual concentration was observed in the wet year, indicating that the hydrological process drove the nutrient transport in the watershed. For the tributaries, the Li River catchment contributed a large amount of N and P to the aquatic environment. For the reservoir, the extreme TN concentrations were the same as the tributaries, while the extremes of TP concentrations decreased from the dry year to wet year, which was in contrast to the tributaries. The spatial variation of TN and TP concentrations in the reservoir showed that the concentration decreased following the flow direction from the river estuary to the reservoir outlet. Considering climate change, with the increase of rainfall in North China in the future, the TN and TP transport fluxes in the watershed may continue to increase, leading to the nitrogen and phosphorus load of the downstream reservoir. To ensure the impact of the increase of potential N and P output fluxes in the watershed on the water quality of the reservoir area, it is necessary to strengthen the effective prevention and control of non-point source pollution in the watershed. Full article

(This article belongs to the Special Issue Sources, Migration and Transformation Processes of Pollutants in the Terrestrial Environment)

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15 pages, 3705 KiB

Open AccessArticle

The Impacts of Nitrogen Pollution and Urbanization on the Carbon Dioxide Emission from Sewage-Draining River Networks

by Yongmei Hou, Xiaolong Liu, Guilin Han, Li Bai, Jun Li and Yusi Wang

Int. J. Environ. Res. Public Health 2022, 19(16), 10296; https://doi.org/10.3390/ijerph191610296 - 18 Aug 2022

Cited by 4 | Viewed by 1647

Abstract

Carbon dioxide (CO₂) emissions from river water have sparked worldwide concerns due to supersaturate CO₂ levels in the majority of global rivers, while the knowledge on the associations among nitrogen pollution, urbanization, and CO₂ emissions is still limited. In [...] Read more.

Carbon dioxide (CO₂) emissions from river water have sparked worldwide concerns due to supersaturate CO₂ levels in the majority of global rivers, while the knowledge on the associations among nitrogen pollution, urbanization, and CO₂ emissions is still limited. In this study, the CO₂ partial pressure (pCO₂), carbon and nitrogen species, and water parameters in sewage-draining river networks were investigated. Extremely high pCO₂ levels were observed in sewage and drainage river waters, such as Longfeng River, Beijing-drainage River, and Beitang-drainage River, which were approximately 4 times higher than the averaged pCO₂ in worldwide rivers. Correlations of carbon/nitrogen species and pCO₂ indicated that carbon dioxide in rural rivers and sewage waters primarily originated from soil aeration zones and biological processes of organic carbon/nitrogen input from drainage waters, while that in urban rivers and lakes was mainly dominated by organic matter degradation and biological respiration. Enhanced internal primary productivity played critical roles in absorbing CO₂ by photosynthesis in some unsaturated pCO₂ sampling sites. Additionally, higher pCO₂ levels have been observed with higher NH₄⁺-N and lower DO. CO₂ fluxes in sewage waters exhibited extremely high levels compared with those of natural rivers. The results could provide implications for assessing CO₂ emissions in diverse waters and fulfilling water management polices when considering water contamination under intense anthropogenic activities. Full article

(This article belongs to the Special Issue Sources, Migration and Transformation Processes of Pollutants in the Terrestrial Environment)

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17 pages, 3382 KiB

Open AccessArticle

Source Identification and Health Risk Assessment of Heavy Metals in Soil: A Case Study of Lintancang Plain, Northeast China

by Qianru Man, Lijuan Xu and Mingfang Li

Int. J. Environ. Res. Public Health 2022, 19(16), 10259; https://doi.org/10.3390/ijerph191610259 - 18 Aug 2022

Cited by 3 | Viewed by 1727

Abstract

To investigate the concentration, source, and potential health risk of soil heavy metals (V, Cr, Ni, Cu, Zn, Pb, Hg), this study determined the concentration of these seven metals in 37 soil samples from Linyi City, southeast of Shandong Province, China. The mean [...] Read more.

To investigate the concentration, source, and potential health risk of soil heavy metals (V, Cr, Ni, Cu, Zn, Pb, Hg), this study determined the concentration of these seven metals in 37 soil samples from Linyi City, southeast of Shandong Province, China. The mean concentrations of the investigated heavy metals followed the sequence: Cr (76.2 mg/kg) > V (70.5 mg/kg) > Zn (70.1 mg/kg) > Ni (34.0 mg/kg) > Pb (31.4 mg/kg) > Cu (23.2 mg/kg) > Hg (1.7 mg/kg). The enrichment factor (EF) and geo-accumulation index (I_geo) indicated an extreme enrichment of Hg (EF > 10, I_geo > 4) within the study area, while a slight enrichment of other metals. According to the toxic risk index (TRI), Hg accounted for the strongest soil toxicity (TRI = 8.07, 64.3%). The risk assessment with hazard index (HI) suggested that the health risks of all metals were acceptable, and the HI of adults was generally lower compared with that of the children. In addition, two principal components (PC) calculated by principal component analysis (PCA) were used to identify the sources of these heavy metals, which were 57.73% for PC 1 (Pb, Cr, Zn, Ni, Hg, Cu and V) and 21.63% for PC 2 (Hg, Cu and V), respectively. Moreover, PC 1 was mainly controlled by anthropogenic inputs, while PC 2 was contributed to by natural sources. Combined with the correlation matrix, it was concluded that there were three different sources for all seven heavy metals. Full article

(This article belongs to the Special Issue Sources, Migration and Transformation Processes of Pollutants in the Terrestrial Environment)

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18 pages, 3124 KiB

Open AccessArticle

Spectroscopic Characteristics and Speciation Distribution of Fe(III) Binding to Molecular Weight-Dependent Standard Pahokee Peat Fulvic Acid

by Yaqin Zhang, Chang Liu, Yuxia Li, Liuting Song, Jie Yang, Rui Zuo, Jian Li, Yanguo Teng and Jinsheng Wang

Int. J. Environ. Res. Public Health 2022, 19(13), 7838; https://doi.org/10.3390/ijerph19137838 - 26 Jun 2022

Cited by 3 | Viewed by 2081

Abstract

Peat-derived organic matter, as powerful chelators, is of great significance for the transport of Fe to the ocean and the enhancement of dissolved Fe. However, the iron binding capacity of molecular weight (MW)-fractionated dissolved organic matter is variable, due to its structure and [...] Read more.

Peat-derived organic matter, as powerful chelators, is of great significance for the transport of Fe to the ocean and the enhancement of dissolved Fe. However, the iron binding capacity of molecular weight (MW)-fractionated dissolved organic matter is variable, due to its structure and composition heterogeneity. In this work, we used the standard Pahokee Peat fulvic acid (PPFA) as an example, and investigated the spectroscopy properties and Fe(III) binding ability of PPFA and different molecular weight fractions by UV–Vis absorbance and fluorescence spectroscopy and the Donnan Membrane Technique (DMT). The results showed binding sites for Fe(III) at the 263 nm and >320 nm regions in differential absorbance spectra. Upon increasing the iron concentration to 18.00 μmol·L⁻¹, the critical binding capacity was exceeded, which resulted in a decrease in absorbance. Fe(III) was found to prefer to bind to humic-like components, and ultraviolet humic-like fluorophores displayed stronger binding strength. High molecular weight PPFA fractions (>10 kDa) possessed more aromatic and hydrophobic components, displayed a higher degree of humification, and exhibited higher metal binding potential. Furthermore, the speciation analysis and stability constant (^cK) were calculated using Donnan membrane equilibrium. The correlation between ^cK values and PPFA spectral properties demonstrated that aromaticity, hydrophobicity, molecular weight and humification degree were crucial indices of PPFA–Fe(III) affinity. Significantly, the humification degree, represented by HIX, showed the strongest correlation (r = 0.929, p = 0.003), which could be used to estimate the binding strength. This study provides further understanding of the complexation mechanism of iron and DOM in the peat environment and identifies the considerable effect of molecular weight. Full article

(This article belongs to the Special Issue Sources, Migration and Transformation Processes of Pollutants in the Terrestrial Environment)

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17 pages, 1817 KiB

Open AccessArticle

Changes in the Dissolved Organic Matter Characteristics Released from Sediment According to Precipitation in the Namhan River with Weirs: A Laboratory Experiment

by Haeseong Oh and Jung-Hyun Choi

Int. J. Environ. Res. Public Health 2022, 19(9), 4958; https://doi.org/10.3390/ijerph19094958 - 19 Apr 2022

Cited by 8 | Viewed by 1973

Abstract

In this study, changes in the properties of dissolved organic matter (DOM) released from sediments into water layers were investigated. To analyze the spatial and temporal variation in dissolved organic carbon (DOC), sediment and bottom water samples were collected upstream of the Gangcheon, [...] Read more.

In this study, changes in the properties of dissolved organic matter (DOM) released from sediments into water layers were investigated. To analyze the spatial and temporal variation in dissolved organic carbon (DOC), sediment and bottom water samples were collected upstream of the Gangcheon, Yeoju, and Ipo weirs of the Namhan River during the rainy and non-rainy seasons. The initial DOC was correlated with precipitation (R² = 0.295, p = 0.034) and residence time (R² = 0.275, p = 0.040). The change in the bottom water DOC concentration resulted from the DOC released from the sediments, which may cause water quality issues in the bottom water. The fluorescence analysis revealed that the DOM contained higher levels of hydrophilic and low-molecular-weight (LMW) organic matter in the non-rainy season and higher levels of hydrophobic and high-molecular-weight (HMW) organic matter in the rainy season. Since the Namhan River is the main resource of drinking water for the Seoul metropolitan area, our results can help to optimize the drinking water treatment process by reflecting the DOM characteristics that vary with the seasons. Furthermore, the statistical analysis confirmed that the nutrient content of pore-water and sediment can be used to estimate the DOM release rate from the sediment to the water layer. The results of this study provide a better understanding of DOM movement in aquatic ecosystems and the influences of rainfall on the water quality of the surface waterbody. Full article

(This article belongs to the Special Issue Sources, Migration and Transformation Processes of Pollutants in the Terrestrial Environment)

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14 pages, 2001 KiB

Open AccessArticle

Suspended Sediments Quality Assessment in a Coastal River: Identification of Potentially Toxic Elements

by Jie Zeng, Guilin Han, Shitong Zhang and Qian Zhang

Int. J. Environ. Res. Public Health 2022, 19(7), 4293; https://doi.org/10.3390/ijerph19074293 - 3 Apr 2022

Cited by 3 | Viewed by 1886

Abstract

In coastal rivers with various human and damming activities (reservoir), the cycle and biogeochemistry of environmental pollutants in river systems has been modified. A total of 42 suspended particulate matter (SPM) samples were obtained in Jiulongjiang River, southeast China to investigate the concentration, [...] Read more.

In coastal rivers with various human and damming activities (reservoir), the cycle and biogeochemistry of environmental pollutants in river systems has been modified. A total of 42 suspended particulate matter (SPM) samples were obtained in Jiulongjiang River, southeast China to investigate the concentration, sources, behavior, and risks of nine potentially toxic elements (PTEs) in SPM. The results of metals concentration showed relatively large variation, major for Mn and minor for Co; Mn > Zn > V > Pb > Cr > Ni > Cu > Cd > Co. Multi-index evaluation reflected that most of the PTEs are minor enrichment/moderately polluted. The Cd is defined as extremely severe enrichment/polluted level, and the Pb and Zn as minor enrichment/moderately polluted levels. Among the selected PTEs, Cd and Zn are identified as the main toxic factors of SPM with a contribution of 57 ± 18% and 14 ± 7% to the total toxic risk. The sources identification suggested that human inputs may be the primary potential source of Cd, Zn, Pb, and Co, whereas natural sources (e.g., rock weathering) are likely to be responsible for Cu, Cr, V, and Ni. In contrast, the data suggested that Mn may be attributed to both natural and anthropogenic inputs. The PTEs among dissolved, suspended, and sediment phases reflected the transportation behavior and different potential risk levels. Overall, the PTE geochemistry of river SPM can act as a good indicator of the driving mechanism of PTEs’ accumulation and provide a powerful support for controlling riverine PTEs-related pollution in coastal regions. Full article

(This article belongs to the Special Issue Sources, Migration and Transformation Processes of Pollutants in the Terrestrial Environment)

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15 pages, 33187 KiB

Open AccessArticle

Heavy Metal Pollution and Soil Quality Assessment under Different Land Uses in the Red Soil Region, Southern China

by Zhiping Yang, Rong Zhang, Hongying Li, Xiaoyuan Zhao and Xiaojie Liu

Int. J. Environ. Res. Public Health 2022, 19(7), 4125; https://doi.org/10.3390/ijerph19074125 - 31 Mar 2022

Cited by 13 | Viewed by 2534

Abstract

The influences of different land uses associated with human activities on soil quality and the redistribution of heavy metal in soil have been widely concerned. Surface soil samples were obtained to assess comprehensive soil quality in a typical red soil region of southern [...] Read more.

The influences of different land uses associated with human activities on soil quality and the redistribution of heavy metal in soil have been widely concerned. Surface soil samples were obtained to assess comprehensive soil quality in a typical red soil region of southern China, combining the heavy metal pollution evaluation with fertility evaluation. It can be learned from the results that the overall level of soil fertility was at medium and lower level, and soil heavy metal pollution risk in the study area in a few regions had reached warning line and slight pollution line, and there was a risk of potential pollution. TOPSIS evaluation results showed that the comprehensive soil quality was mainly good quality and moderate quality, accounting for 31.7% and 29.0% of the total land area, respectively. Positive matrix factorization (PMF) model results showed that transportation source contributes a lot in terms of Cd and Pb. As for Cr, natural source contributes 53.8%. In terms of Cu and Zn, agriculture source contributes 50.7% and 38.7%, respectively. In a word, the comprehensive soil quality assessment in red soil region of southern China provides an important basis for the scientific management and sustainable utilization of soil resources. Full article

(This article belongs to the Special Issue Sources, Migration and Transformation Processes of Pollutants in the Terrestrial Environment)

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15 pages, 2959 KiB

Open AccessArticle

Geochemical and Statistical Analyses of Trace Elements in Lake Sediments from Qaidam Basin, Qinghai-Tibet Plateau: Distribution Characteristics and Source Apportionment

by Haifang He, Haicheng Wei, Yong Wang, Lingqing Wang, Zhanjie Qin, Qingkuan Li, Fashou Shan, Qishun Fan and Yongsheng Du

Int. J. Environ. Res. Public Health 2022, 19(4), 2341; https://doi.org/10.3390/ijerph19042341 - 18 Feb 2022

Cited by 7 | Viewed by 2486

Abstract

The safety of lake ecosystems on the Qinghai-Tibet Plateau (QTP) has attracted increasing attention, owing to its unique location and ecological vulnerability. Previous studies have shown that the aquatic systems on the QTP have been polluted to varying degrees by trace elements. However, [...] Read more.

The safety of lake ecosystems on the Qinghai-Tibet Plateau (QTP) has attracted increasing attention, owing to its unique location and ecological vulnerability. Previous studies have shown that the aquatic systems on the QTP have been polluted to varying degrees by trace elements. However, little is known of the distribution and sources of trace elements in lakes in the northeast QTP. Here, 57 sediment samples were collected from six lakes (Dasugan Lake, Xiaoqaidam Lake, Kreuk Lake, Toson Lake, Gahai Lake and Xiligou Lake) in the Qaidam Basin, northeast QTP, and the trace elements (V, Cr, Ni, Cu, Zn, As, Ba, Tl, Cd, Pb, and U) were analyzed. The results indicated that Ba, Zn, V, and Cr had a higher content and a wider distribution relative to the other tested elements. Correlation coefficient matrix results showed that the trace elements in the study area were strongly correlated, revealing their source of similarity. Self-organizing maps (SOM, an artificial neural network algorithm) results indicated that the degree of pollution in Xiaoqaidam Lake was the highest, and that of Dasugan Lake was the lowest. Furthermore, all sampling points were clustered into four categories through K-means clustering. The positive matrix factorization (PMF) results indicated that atmospheric deposition and anthropogenic inputs were the main trace elements sources in these lakes, followed by traffic emission and geological sources. Collectively, trace elements of six lakes in Qinghai-Tibet Plateau presented high-content and pollution characteristics. This research provides a scientific basis for better water environment management and ecological protection on the QTP. Full article

(This article belongs to the Special Issue Sources, Migration and Transformation Processes of Pollutants in the Terrestrial Environment)

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