Characteristics and Potential Ecological Risks of Heavy Metal Content in the Soil of a Plateau Alpine Mining Area in the Qilian Mountains

In recent years, the ecological and environmental problems caused by mining in the Qilian Mountains have attracted considerable attention, and the government has carried out a number of comprehensive ecological environment remediation projects there, among which ecological restoration in the Qilian...

Full description

Bibliographic Details
Main Authors: Fuling Zhang, Guangchao Cao, Shengkui Cao, Zhuo Zhang, Hongda Li, Gang Jiang
Format: Article
Language:English
Published: MDPI AG 2023-09-01
Series:Land
Subjects:
Online Access:https://www.mdpi.com/2073-445X/12/9/1727
_version_ 1797579221762048000
author Fuling Zhang
Guangchao Cao
Shengkui Cao
Zhuo Zhang
Hongda Li
Gang Jiang
author_facet Fuling Zhang
Guangchao Cao
Shengkui Cao
Zhuo Zhang
Hongda Li
Gang Jiang
author_sort Fuling Zhang
collection DOAJ
description In recent years, the ecological and environmental problems caused by mining in the Qilian Mountains have attracted considerable attention, and the government has carried out a number of comprehensive ecological environment remediation projects there, among which ecological restoration in the Qilian Mountain alpine mining area is an essential task. As a result, heavy metals have been studied in the soil of the Qilian Mountain alpine mining area. This can provide a scientific basis and data support for the establishment of a demonstration index for monitoring ecological environmental restoration in mining areas. In order to understand the content and contamination status of heavy metals in the soil surrounding the alpine mining area of Qilian Mountain, 56 soil samples were collected to determine the levels of eight heavy metals, including Cd, Hg, As, Pb, Cr, Cu, Zn, and Ni. The spatial distribution of heavy metals in the soil of the study area was analyzed based on a statistical approach. The single-factor pollution index (Pi), Nemerow comprehensive pollution index (PN), geoaccumulation index (Igeo), and potential ecological risk index (RI) were used to evaluate soil heavy metal pollution and potential ecological risk. Principal component analysis (PCA), positive matrix factorization (PMF) models, and geostatistical analysis were also used to investigate the source of heavy metals. The results show that the average Cd, As, Cr, Cu, Zn, and Ni content of the grassland soil around the mining area exceeds the soil background values in both Qinghai Lake Basin and Qinghai Province. The spatial distribution of the eight heavy metal elements in soil showed an island-like pattern, with high-value areas of each metal element appearing, indicating that human activities in the study area had negative effects on the soil environment. The value of the single pollution index showed that levels of Ni, Cd, Cu, Cr, Hg, and As pollution were low, while there was no Pb or Zn pollution. The Nemerow integrated pollution index had an average value of 1.39, indicating a slight pollution trend. The average values of Cr and Zn in the geoaccumulation index ranged from 0 to 1, indicating mild to moderate contamination in the studied region. The average value of the integrated ecological risk index in the study area was 135.43, which is in the intermediate ecological risk range. In descending order of size, the average ecological risk index of each heavy metal element was Hg > Cd> As > Ni > Cu > Pb > Cr > Zn. From the perspective of the spatial distribution pattern of ecological risk, the two high-value discriminants were in the western part of the study area, close to the mining area. Zn, Cu, Pb, and Cd in soils were mainly affected by human activity, while Cr and Ni were mainly affected by soil geochemistry. Cd is the main contaminant in the study area, and soil Cd contamination of the grassland in the study area must be considered.
first_indexed 2024-03-10T22:32:49Z
format Article
id doaj.art-3ffb3641c033453abdbbdead6ad363dc
institution Directory Open Access Journal
issn 2073-445X
language English
last_indexed 2024-03-10T22:32:49Z
publishDate 2023-09-01
publisher MDPI AG
record_format Article
series Land
spelling doaj.art-3ffb3641c033453abdbbdead6ad363dc2023-11-19T11:34:04ZengMDPI AGLand2073-445X2023-09-01129172710.3390/land12091727Characteristics and Potential Ecological Risks of Heavy Metal Content in the Soil of a Plateau Alpine Mining Area in the Qilian MountainsFuling Zhang0Guangchao Cao1Shengkui Cao2Zhuo Zhang3Hongda Li4Gang Jiang5College of Geography Science, Qinghai Normal University, Xining 810008, ChinaCollege of Geography Science, Qinghai Normal University, Xining 810008, ChinaCollege of Geography Science, Qinghai Normal University, Xining 810008, ChinaEnvironmental Monitoring Station of Kezilsu Prefecture, Atushi 845350, ChinaQinghai General Station of Grassland, Xining 810008, ChinaCollege of Geography Science, Qinghai Normal University, Xining 810008, ChinaIn recent years, the ecological and environmental problems caused by mining in the Qilian Mountains have attracted considerable attention, and the government has carried out a number of comprehensive ecological environment remediation projects there, among which ecological restoration in the Qilian Mountain alpine mining area is an essential task. As a result, heavy metals have been studied in the soil of the Qilian Mountain alpine mining area. This can provide a scientific basis and data support for the establishment of a demonstration index for monitoring ecological environmental restoration in mining areas. In order to understand the content and contamination status of heavy metals in the soil surrounding the alpine mining area of Qilian Mountain, 56 soil samples were collected to determine the levels of eight heavy metals, including Cd, Hg, As, Pb, Cr, Cu, Zn, and Ni. The spatial distribution of heavy metals in the soil of the study area was analyzed based on a statistical approach. The single-factor pollution index (Pi), Nemerow comprehensive pollution index (PN), geoaccumulation index (Igeo), and potential ecological risk index (RI) were used to evaluate soil heavy metal pollution and potential ecological risk. Principal component analysis (PCA), positive matrix factorization (PMF) models, and geostatistical analysis were also used to investigate the source of heavy metals. The results show that the average Cd, As, Cr, Cu, Zn, and Ni content of the grassland soil around the mining area exceeds the soil background values in both Qinghai Lake Basin and Qinghai Province. The spatial distribution of the eight heavy metal elements in soil showed an island-like pattern, with high-value areas of each metal element appearing, indicating that human activities in the study area had negative effects on the soil environment. The value of the single pollution index showed that levels of Ni, Cd, Cu, Cr, Hg, and As pollution were low, while there was no Pb or Zn pollution. The Nemerow integrated pollution index had an average value of 1.39, indicating a slight pollution trend. The average values of Cr and Zn in the geoaccumulation index ranged from 0 to 1, indicating mild to moderate contamination in the studied region. The average value of the integrated ecological risk index in the study area was 135.43, which is in the intermediate ecological risk range. In descending order of size, the average ecological risk index of each heavy metal element was Hg > Cd> As > Ni > Cu > Pb > Cr > Zn. From the perspective of the spatial distribution pattern of ecological risk, the two high-value discriminants were in the western part of the study area, close to the mining area. Zn, Cu, Pb, and Cd in soils were mainly affected by human activity, while Cr and Ni were mainly affected by soil geochemistry. Cd is the main contaminant in the study area, and soil Cd contamination of the grassland in the study area must be considered.https://www.mdpi.com/2073-445X/12/9/1727plateau alpineheavy metalspotential ecological riskpollution assessmentsoilsouthern piedmont of Qilian Mountains
spellingShingle Fuling Zhang
Guangchao Cao
Shengkui Cao
Zhuo Zhang
Hongda Li
Gang Jiang
Characteristics and Potential Ecological Risks of Heavy Metal Content in the Soil of a Plateau Alpine Mining Area in the Qilian Mountains
Land
plateau alpine
heavy metals
potential ecological risk
pollution assessment
soil
southern piedmont of Qilian Mountains
title Characteristics and Potential Ecological Risks of Heavy Metal Content in the Soil of a Plateau Alpine Mining Area in the Qilian Mountains
title_full Characteristics and Potential Ecological Risks of Heavy Metal Content in the Soil of a Plateau Alpine Mining Area in the Qilian Mountains
title_fullStr Characteristics and Potential Ecological Risks of Heavy Metal Content in the Soil of a Plateau Alpine Mining Area in the Qilian Mountains
title_full_unstemmed Characteristics and Potential Ecological Risks of Heavy Metal Content in the Soil of a Plateau Alpine Mining Area in the Qilian Mountains
title_short Characteristics and Potential Ecological Risks of Heavy Metal Content in the Soil of a Plateau Alpine Mining Area in the Qilian Mountains
title_sort characteristics and potential ecological risks of heavy metal content in the soil of a plateau alpine mining area in the qilian mountains
topic plateau alpine
heavy metals
potential ecological risk
pollution assessment
soil
southern piedmont of Qilian Mountains
url https://www.mdpi.com/2073-445X/12/9/1727
work_keys_str_mv AT fulingzhang characteristicsandpotentialecologicalrisksofheavymetalcontentinthesoilofaplateaualpineminingareaintheqilianmountains
AT guangchaocao characteristicsandpotentialecologicalrisksofheavymetalcontentinthesoilofaplateaualpineminingareaintheqilianmountains
AT shengkuicao characteristicsandpotentialecologicalrisksofheavymetalcontentinthesoilofaplateaualpineminingareaintheqilianmountains
AT zhuozhang characteristicsandpotentialecologicalrisksofheavymetalcontentinthesoilofaplateaualpineminingareaintheqilianmountains
AT hongdali characteristicsandpotentialecologicalrisksofheavymetalcontentinthesoilofaplateaualpineminingareaintheqilianmountains
AT gangjiang characteristicsandpotentialecologicalrisksofheavymetalcontentinthesoilofaplateaualpineminingareaintheqilianmountains