Effects of mining activities on the distribution, controlling factors, and sources of metals in soils from the Xikuangshan South Mine, Hunan Province

Abstract

In this study, we analyzed 53 topsoil samples from the Xikuangshan South Mine in Hunan Province to investigate the distribution characteristics of pH and the concentrations of selected metals to determine the controlling factors and identify their sources. Kriging interpolation, correlation analysis, principal component analysis, the index of the geoaccumulation index, and Hakanson's potential ecological risk were applied. The results show that the mean values of Pb, As, Cd, and Sb in the study area were larger than the background value of mountain soil in Hunan Province, and only the average Cr concentration was slightly lower than the background value. The spatial distributions of pH and five metals in the soil were very different, indicating that pH had no significant effect on the distribution of the metals. The wind, rivers, and land-use patterns in different regions of the study area may be the main reasons for their distribution patterns. The correlation component and principal component analysis revealed that Pb showed positive correlations with Cr and Cd, respectively, and Sb-As and Cr-Cd showed strong paired correlations. The cumulative proportion of the first two components accounted for 70.516% of the total variance, which suggests that mining activities are a major source of As and Sb, whereas Pb, Cr, and Cd were derived from natural and anthropogenic sources. The geoaccumulation index revealed that the major pollutants in the soils were mainly Cd, followed by Sb and As. The soils in the study area were moderately contaminated with Pb and lightly polluted by Cr. The ecological hazards of each metal in descending order were Cd > Sb > As > Pb > Cr. The index of the comprehensive potential ecological risk for metals indicated that the Xikuangshan South Mine is at or above a moderate ecological risk level, with an extremely strong potential for ecological risks posed by Cd and Sb.

Geochemical Baseline of Heavy Metals in Topsoil on Local Scale and Its Application

“…Geoaccumulation Index (I geo ) I geo was proposed by Muller in 1969 for quantitative evaluation of sediments [20]. This method is widely used to evaluate the accumulation degree of heavy metals in topsoil [21][22][23][24][25]. I geo not only reflects the natural change of heavy metal distribution, but also can judge the impact of human activities on the environment.…”

Effect of Different Modification Methods on the Adsorption of Manganese by Biochar from Rice Straw, Coconut Shell, and Bamboo

“…With the rapid development of the manganese mining and industry, the concentration of Mn in water is increasing. It has preoccupied a growing number of scientists in recent years …”

“…It has preoccupied a growing number of scientists in recent years. 4 Biochar has been widely used as adsorbents for removing pollutants from water and wastewater due to its special surface structure. 5 Numerous factors including feedstocks and operation parameters of the pyrolysis process (temperature, duration, heating rate, and pressure) affect the yield and quality of biochar.…”

Nonlinear Strength Reduction Method of Rock Mass in Slope Stability Evaluation

“…Landslides are one of the most dangerous geological disasters, causing heavy casualties and economic losses around the world [ 1 , 2 , 3 , 4 ]. In rock projects such as transportation, hydropower and mining, the original stable slopes are easily affected by the disturbance of engineering excavations [ 5 , 6 , 7 , 8 ], leading to more destructive disasters such as landslides and collapses [ 9 ], such as landslides occurred on the expressway [ 10 ] ( Figure 1 ). The bearing capacity estimation has always been an important issue in the field of geotechnical engineering [ 11 , 12 ], which is also the basis for project design.…”

“…In this case, Hoek et al [ 58 , 59 ] further improved the original results and proposed generalized Hoek–Brown strength criteria for rock mass of different quality, which is presented in Equation (2). In 2002, Hoek et al [ 5 , 6 , 7 , 8 ] comprehensively discussed the Hoek–Brown parameter relations, and built a new determination method of parameters m b , s and a by introducing geological strength index GSI and disturbance factor D (see Equations (3)–(5)). At present, the Hoek–Brown strength criterion has been widely used in rock and rock mass mechanics analysis, rock slope stability analysis, rock tunnel design and other fields [ 60 ].…”