Geochemical Study Of Soils Research Articles

Features of heavy metals and metalloids accumulation in soils of Samara and Syzran large recreational zones

The paper discusses the results of ecological and geochemical studies of soils in the Sokolii Mountains located near Samara and in a specially protected natural area Monastyrskaya Mountain located within the borders of Syzran, Samara Region. These territories are of great interest in connection with their active use for urban recreation. The studied parts of the Sokolii Mountains (northeastern, eastern and southeastern surroundings of the Kuznetsov Mountain) are natural forests, the protected area Monastyrskaya Mountain is an artificially created forest stand. The territories under comparison differ in their origin, typological characteristics of soils, including their granulometric composition and humus content, as well as in the degree of recreational pressure. It has been established that heavy metals and metalloids accumulate more actively (2,05,5 times) in the soils of the upper layer in the vicinity of the Kuznetsov Mountain than in the sandy and loamy soils of the Monastyrskaya Mountain, which are characterized by a more significant geochemical heterogeneity. In both territories, the average concentrations of chemical elements do not exceed regional clarks and maximum permissible concentrations. An analysis of the geochemical indices of the studied soils revealed the predominance of the scattering of heavy metals and metalloids over the concentration processes in them. According to the magnitude of concentration clarks and scattering for both recreational territories, an association of accumulating elements was revealed; it included only Se and Cd while the association of scattering elements included Sr, Rb, Cr, V, As, Pb, Ni, Co, Cu, Zn, Mn. In the soils of the Monastyrskaya Mountain dispersal processes are more presented while in the soils of the Kuznetsov Mountain surroundings accumulation processes are more presented. In general, the northeastern, eastern and southeastern environments of the Kuznetsov Mountain and the Monastyrskaya Mountain are characterized by a relatively low level of heavy metals and metalloids pollution, which makes it possible to consider these territories as environmentally sustainable, but requiring the development of a scientifically-based mode of recreational use.

Geochemical Study of Soils, Road Dust and Stream Sediments around Ijebu-Ode, Southwestern, Nigeria

The study was aimed at an assessment of the heavy metal distribution in soils, road dust and stream sediments of the city of Ijebu-Ode in order to evaluate the effects of increased urbanization on the quality of the environmental media89 samples comprising 30 topsoil, 54 road dust and 5 stream sediments samples were collected. The samples were air-dried, disaggregated and sieved for the fine fractions (< 75 μm). Portion of the samples were soaked in deionized water for forty-eight hours in the laboratory and the resulting solution was measured for Electrical Conductivity (EC), pH and Total Dissolved Solids (TDS) using standard digital probes. 0.5 g of the fine fractions of each sample was subsequently digested using hoy aqua-regia and analyzed for elemental concentration using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The sieve analysis showed that the soils in the area are silty-sands in nature. The measured pH ranges from (6.1 to 7.6); (6.1-7.6) and (7.0-7.2) for Soil, road dust and stream sediments respectively. The EC ranges from (1-131 μS/cm); (6-27 μS/cm) and (24-387 μS/cm) in soil, stream sediments and in road dust while the TDS ranges from (0.4-89 mg/l); (3-16 mg/l) and (13-248 mg/l) in soils, stream sediments and in road dust. The elemental analysis revealed the following trends for selected metals in soils, sediments and road dusts respectively Cu (9.0-23.0, 12.0-1170 and 7.0-37.0); Pb (11.0-1056, 14.0-679.0 and 16.0-127.0); Zn (15.0-348.0, 86.0-730.0 and 36.0-412.0); Ni (6.0-12, 5.0-21.0 and 4.0-15.0); V(35.0-121.0, 34.0-113.0 and 29.0-135.0), Cr (25.0-94.0, 34.0-213.0 and 36.0-177.0) and As (2.0-11.0, 2.0-22.0 and Below detection limit, bdl-19.0). Further geochemical evaluation of the metals using metal ratio, geo-accumulation index revealed significant concentration of Cu, Pb, Zn, Ni, As and Cr in the environmental media from within the city Centre and along major roads in the city. Extreme metal loads associated with areas of huge vehicular activities, waste dumps and zones with agricultural activities.

Determination of geochemical background for environmental studies of soils via the use of HNO3 extraction and Q–Q plots

The procedure proposed in this study is based on the extraction of elements in soils by analytical grade HNO3, the distribution of the elemental data displayed on probability graphs (Q–Q plots) and the visualization of the results spatially by GIS software. The applicability of the procedure is demonstrated in an urban area and its surroundings (Kavala, northern Greece). A major (Ca) and a trace (Ag) element are used as examples in order to demonstrate the applicability of the proposed procedure. Normal probability and lognormal probability plots of Ca and Ag show that their concentrations are lognormally distributed and that their geochemical baseline and anomaly threshold values can be calculated with the aid of their geometric mean and geometric deviation. The advantages of the proposed procedure are simplicity, comprehensiveness, and low cost. It can be applied to environmental geochemical studies of soils in a variety of areas.

Factor analysis applied to a geochemical study of soils from parts of Medak and Sangareddy areas, Medak district, Andhra Pradesh, India

Preliminary investigations were carried out in and around Medak and Sangareddy areas to study the baseline levels of ten major (Si, Al, Ca, Fe, K, Mg, Mn, Na, P, and Ti) and 14 trace elements (As, Ba, Co, Cr, Cu, Mo, Ni, Pb, Rb, Sr, V, Y, Zn, and Zr) on 97 representative soil samples comprising of topsoil (0-25 cm) and subsoil (90-115 cm). The data was factor analyzed for geochemical associations. Because varimax factor loading values show the best results, these were used in interpretation. The derived factors are usually interpreted as associations of elements that imply a common source or behavior in regard to geogenic or anthropogenic influences. It was found that the difference between topsoil and subsoil is not only expressed by concentration differences but also by element associations. Five factors were extracted in topsoil data and account for 80% of the total data variance, while seven factors were extracted in subsoil, which account for 88% of the total variance, suggesting that metal concentration was controlled by soil composition and also that, apart from natural contributions of trace elements to the soils, human activities like agriculture and industrial growth possibly accounted for elemental inputs in soils.

Uranium Sequestration by Aluminum Phosphate Minerals in Unsaturated Soils

AbstractA mineralogical and geochemical study of soils developed from the unmined Coles Hill uranium deposit (Virginia) was undertaken to determine how phosphorous influences the speciation of uranium in an oxidizing soil/saprolite system typical of the eastern US. This paper presents mineralogical and geochemical results that identify and quantify the processes by which uranium has been sequestered in these soils. It was found that uranium is not leached from the saturated soil zone (saprolites) overlying the deposit due to the formation of a sparingly soluble uranyl phosphate mineral of the meta-autunite group. The concentration of uranium in the saprolites is approximately 1000 mg uranium per kg of saprolite. It was also found that a significant amount of uranium was retained in the unsaturated soil zone overlying uranium-rich saprolites. The uranium concentration in the unsaturated soils is approximately 200 mg uranium per kg of soil (20 times higher than uranium concentrations in similar soils adjacent to the deposit). Mineralogical evidence indicates that uranium in this zone is sequestered by a barium-strontium-calcium aluminum phosphate mineral of the crandallite group (gorceixite). This mineral is intimately inter-grown with iron and manganese oxides that also contain uranium. The amount of uranium associated with both the aluminum phosphates (as much as 1.4 weight percent) has been measured by electron microprobe microanalyses and the geochemical conditions under which these minerals formed has been studied using thermodynamic reaction path modeling. The geochemical data and modeling results suggests the meta-autunite group minerals present in the saprolites overlying the deposit are unstable in the unsaturated zone soils overlying the deposit due to a decrease in soil pH (down to a pH of 4.5) at depths less than 5 meters below the surface. Mineralogical observations suggest that, once exposed to the unsaturated environment, the meta-autunite group minerals react to form U(VI)-bearing aluminum phosphates.

Geochemical study of soils and metallogenetic implications at Hiendelaencina, Guadalajara, Spain

A geochemical soil survey has been carried out near a known mineralized vein in the argentiferous area of Hiendelaencina, Spain. The distribution of Ag, Sb, As, Ba, Pb, Zn, Cu, Fe, Mn, Ni and Co was studied and the results treated with univariate and multivariate analysis. The geochemical halo around the known mineralization shows a longitudinal variation giving rise to specific element associations i.e. As-Sb-Ag(-Mn), Fe-Mn-Cu-Ni and Zn-Pb-Ba. About 500 m to the south of the known mineralization a strong geochemical anomaly of As, Sb and Ag is probably produced by a new vein. The whole pattern of anomalies and element associations is in agreement with existing metallogenetic hypotheses.