scholarly journals The Risk Assessment of Sediment Heavy Metal Pollution in the East Dongting Lake Wetland

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Cong Hu ◽  
Zheng-miao Deng ◽  
Yong-hong Xie ◽  
Xin-sheng Chen ◽  
Feng Li

Total concentrations of cadmium (Cd), lead (Pb), chrome (Cr), and nickel (Ni) in surface sediment (0–10 cm) from the East Dongting Lake wetlands were determined and the spatial distribution of heavy metals was mapped. The results showed that the single risk indices (Eri) of heavy metals were ranked in the order of Cd > Pb > Ni > Cr. The content of Cd and Pb was gradually reduced from the east (Xiangjiang River) to the west, while the Cr and Ni content had a patchy distribution pattern in the East Dongting Lake wetlands. Cd and Pb contents were correlated with soil pH significantly, while Cr and Ni contents were correlated with soil organic carbon (SOC) and total nitrogen (TN). The origination of heavy metal (Cd, Cr, Ni, and Pb) could be divided into two groups: Cd and Pb from anthropogenic source and Cr and Ni from parent material weathering. Our results indicated that Cd posed a high risk to local ecosystem. The relatively lower pH and higher soil organic carbon (SOC) and total nitrogen (TN) in sediment may inhibit the fixation of heavy metals, which in turn increased the concentration of heavy metal in sediment.

CATENA ◽  
2022 ◽  
Vol 210 ◽  
pp. 105898
Author(s):  
Xin Zhang ◽  
Meng-Jia Li ◽  
Chao Yang ◽  
Lin-Qing Zhan ◽  
Wei Wu ◽  
...  

Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 1060 ◽  
Author(s):  
Jinying Xu ◽  
Yuwei Chen ◽  
Lilin Zheng ◽  
Baogui Liu ◽  
Jinfu Liu ◽  
...  

Heavy metal pollution in sediment is one of the most serious problems in water bodies, including rivers, which can cause secondary pollution when environmental conditions change. In this study, surface sediment samples collected from the four main tributaries of Dongting Lake (i.e., Xiangjiang River (XR), Zishui River (ZR), Yuanjiang River (YR), and Lishui River (LR)) were analyzed for concentrations of Zn, Cr, Cu, As, Cd, and Pb. The spatial distribution, source, and potential ecological risk of these metals were determined. The results suggest a great spatial heterogeneity of heavy metals in the sediment of the studied rivers. Heavy metals had highest concentrations in the sediment of XR, especially midstream and downstream. A principal component analysis (PCA) and correlation analysis indicated that Cd and As were mainly from industrial wastewater and mineral mining, Cr came from natural process and agricultural activities, and Zn and Cu potentially from both. Pb was originated from atmospheric deposition and river inflow transportation. According to the geo-accumulation index ( I g e o ), enrichment factor (EF), and risk index (RI) assessment, heavy metals pollution was highest in the sediment of XR, and Cd was the main pollutant in the sediment of XR, presenting considerable potential ecological risk. This may contribute to heavy metal pollution in Dongting Lake. This paper provides a reference for the aquatic environmental management of heavy metals in Dongting Lake area and its tributaries.


2021 ◽  
Author(s):  
Hao He ◽  
Zhenan Hou ◽  
Sibo Ru ◽  
Junhua Li

Abstract Organic fertilizer substitution technology is an effective measure to solve the excessive application of chemical fertilizers in agricultural production. A pot experiment was set up with 5 treatments: no fertilizer (CK) and organic fertilizer substituting 0% (CF), 8% (OF8), 16% (OF16), and 24% (OF24) of chemical N fertilizer to analyze their effects on maize yield, soil organic carbon (SOC) and its fractions, carbon pool management index (CPMI), nutrients and heavy metals to provide a scientific basis for safe fertilizer application to maize. This study found that OF8, OF16, and OF24 all increased the content and proportion of SOC and labile organic C (LOC) fractions, CPMI, most of the middle and trace elements, and heavy metals content and their pollution indices in soil and grain compared to CF. Grain was more vulnerable to pollution compared to soil. There was a strong positive correlation between the content of middle and trace elements, and heavy metal, SOC and its fractions (except LLOC), and organic fertilizer substitution ratio, all with no significant correlation with yield. OF8 and OF16 promoted maize growth with a significant increase yield of 35.65% and 30.28% (P <0.05), respectively. A comprehensive analysis determined the optimum substitution ratio of 8% (OF8), which can reduce chemical fertilizer and increase yield, improve soil fertility, low heavy metal pollution risk, is beneficial to promote sustainable agricultural development.


Author(s):  
Yiwei Zhao ◽  
Liangmin Gao ◽  
Fugeng Zha ◽  
Xiaoqing Chen ◽  
Xiaofang Zhou ◽  
...  

AbstractDue to the special sensitivity of typical ecologically fragile areas, a series of human life, mining, and other activities have a greater impact on the environment. In this study, three coal mines in Ordos City on the Loess Plateau were selected as the study area, and the pollution levels of heavy metals in the area were studied by measuring As, Hg, Cr, Cd, Cu, Ni, and Pb in the soil of 131 sampling points. Combined with the concept of “co-occurrence network” in biology, the level of heavy metals in soil was studied using geostatistics and remote sensing databases. The results showed that the concentrations of Hg, Cr, Ni, Cu, and Pb in more than half of the sampling points were higher than the local environmental background value, but did not exceed the risk control value specified by China, indicating that human factors have a greater influence, while Cd and As elements are mainly affected Soil parent material and human factors influence. Heavy metal elements have nothing to do with clay and silt but have an obvious correlation with gravel. Cd, Pb, As and Ni, Cd, Cr are all positively correlated, and different heavy metals are in space The distribution also reflects the autocorrelation, mainly concentrated in the northeast of the TS mining area and the middle of the PS mining area.


2021 ◽  
pp. 1-19
Author(s):  
Yingcong Ye ◽  
Yefeng Jiang ◽  
Lihua Kuang ◽  
Yi Han ◽  
Zhe Xu ◽  
...  

2011 ◽  
Vol 57 (1) ◽  
pp. 21-30
Author(s):  
Božena Šoltysová ◽  
Martin Danilovič

Tillage in Relation to Distribution of Nutrients and Organic Carbon in the SoilChanges of total nitrogen, available phosphorus, available potassium and soil organic carbon were observed on gleyic Fluvisols (locality Milhostov) at the following crops: grain maize (2005), spring barley (2006), winter wheat (2007), soya (2008), grain maize (2009). The experiment was realized at three soil tillage technologies: conventional tillage, reduced tillage and no-tillage. Soil samples were collected from three depths (0-0.15 m; 0.15-0.30 m; 0.30-0.45 m). The ratio of soil organic carbon to total nitrogen was also calculated.Soil tillage affects significantly the content of total nitrogen in soil. The difference between the convetional tillage and soil protective tillages was significant. The balance showed that the content of total nitrogen decreased at reduced tillage by 5.2 rel.%, at no-tillage by 5.1 rel.% and at conventional tillage by 0.7 rel.%.Similarly, the content of organic matter in the soil was significantly affected by soil tillage. The content of soil organic carbon found at the end of the research period was lower by 4.1 rel.% at reduced tillage, by 4.8 rel.% at no-tillage and by 4.9 rel.% at conventional tillage compared with initial stage. The difference between the convetional tillage and soil protective tillages was significant.Less significant relationship was found between the soil tillage and the content of available phosphorus. The balance showed that the content of available phosphorus was increased at reduced tillage (by 4.1 rel.%) and was decreased at no-tillage (by 9.5 rel.%) and at conventional tillage (by 3.3 rel.%).Tillage did not significantly affect the content of available potassium in the soil.


2021 ◽  
Author(s):  
Yang Lin ◽  
Kai Luo ◽  
Zilin Su ◽  
Yang Wu ◽  
Wei Xiao ◽  
...  

Abstract The urbanization is regarded as the major factor related to human activities that may interfere with the natural ecosystem. In this study, we have selected the wetland of East Dongting Lake as the research area. We have collected 180 soil samples (within the range of 0–20 cm, and 20cm-40cm), and we have measured the contents of their physicochemical properties (including salinity, pH value, soil particle composition, soil organic carbon, nitrate nitrogen and rapidly available phosphorus) as well as heavy metal elements (including As, Hg, Cd, Pb, Ni and Cr). We have adopted the methods of multivariate statistical analysis and inverse distance weighted (IDW) interpolation, so as to to reveal the sources and distribution characteristics of heavy metal content in soil in the research area. By adopting the potential ecological risk index (PERI) method proposed by Hakanson, we intend to assess the PERI values of heavy metals. Our research findings have shown that: (1) 8 sorts of heavy metals have shown positive correlation with each other. As, Hg and Zn have shown a significantly positive correlation with SOC (P < 0.01); As, Ni, Cr and Zn have shown a significantly positive correlation with AP (P < 0.01); As and Pb have shown a significantly positive correlation with Clay (P < 0.01); whereas Hg and Zn have shown a significantly negative correlation with Silt (P < 0.01); As and Pb have shown a significantly negative correlation with Sand (P < 0.01). (2) During urbanization, the elements of Cd, Ni, As, Hg and Pb might be enriched due to agricultural and industrial activities, whereas the use of fertilizers and pesticides constitute one of the major factors contributing to the increase of Cd and Pb contents in soil. (3) Influenced by the varying land patterns and with exception to Cu, the Fe-normalized concentrations have shown significant variations among different types of land use (P < 0.05). Specifically, there is a significantly higher level of Cd, Zn, Pb and Hg contents in the agricultural land than other types of land use, whereas there is a slightly higher level of heavy metal content in the mudflats than that in the grassland. In addition, the content of heavy metals in woodland remains relatively stable, and with exception to As, the content of heavy metals in woodland is the lowest among the five types of land. (4) The average value of the comprehensive PERI in heavy metals amounts to 555.03, representing a strong degree of ecological risks. Specifically, the proportion of sampling points of Cd that have a high level of ecological risks amounts to 36.51%, which is the primary element contributing to heavy metal pollution in the region, especially in the agricultural land.


Sign in / Sign up

Export Citation Format

Share Document