Distribution Of Metals In Soils Research Articles

Effect of Cassava Whey on the Physicochemical Parameters and Heavy Metals Distribution in Soil

The processes involved in the conversion of cassava tuber into various products generate large volumes of wastes in solid, liquid and gaseous forms. These wastes when discharged into the environment have serious environmental impacts on the natural composition and structure of soil. The aim of this research work was to investigate the effects of cassava whey on the physicochemical properties and metal contents of soil samples around Gari facrory at Erinfun Village along Federal Polytechnic road, Ado-Ekiti. The physicochemical parameters determined were the pH, moisture content, loss on ignition, organic matter, water holding capacity, bulk density, particle density, total porosity, calcium (Ca), magnesium (Mg) and cyanide (CN). Heavy metals determined were lead (Pb), zinc (Zn), copper (Cu), manganese (Mn), cadmium (Cd), chromium (Cr) and iron (Fe). The presence of cassava whey in the soil led to increasing soil acidity, moisture content, water holding capacity, CN, Cr, Ni, Pb and As concentrations while reductions were observed in total porosity, organic matter, loss on ignition, particle density, Ca, Mg, Fe, Mn and Zn concentrations. The results show appreciable variations of physicochemical parameters and heavy metal contents when compared to the control sample.

Synchrotron Characterization of Metal Distributions in Soils Collected in the Greater Kamloops Region, British Columbia, Canada

Synchrotron Characterization of Metal Distributions in Soils Collected in the Greater Kamloops Region, British Columbia, Canada

Source Identification and Spatial Distribution of Heavy Metals in Soils in Typical Areas Around the Lower Yellow River

A total of 234 surface soil samples (0-20 cm) were collected at the nodes of a 2×2 km grid from Gaoqing County (a typical area surrounding the Lower Yellow River) and analyzed for eight heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn). This study investigated the source of the heavy metals in this area based on a correlation analysis, PCA, and ANOVA using multivariate statistical analysis. In addition, the spatial variation and distribution characteristics of the heavy metals were determined by geostatistics based on GIS. The results provided the following conclusions. ① The mean concentrations of As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn exceeded the background values (BV) of the Lower Yellow River, especially for As, Cu, and Hg (1.23, 1.20 and 1.29 times the BV, respectively), indicating that there was enrichment of the heavy metals in soils at different degrees. ② The results from the multivariate analysis suggested that all eight heavy metals could be classified by two principal components (PCs). The levels of As, Cd, Cr, Cu, Ni, Pb, and Zn were dominated by human activities and the parent soil material (PC1). However, Hg originated mainly from textile printing, petrochemical engineering, and plastic processing (PC2). ③ The differences in heavy metal contents between different land use types and parent soil materials were obvious. The eight elements were highest in land related to urban construction. In addition to Hg, the remaining seven heavy metals were highest in soils in the lacustrine deposit. ④ The spatial distributions of the heavy metals in the soil were different. The high value areas of As, Cd, Cr, Cu, Ni, Pb, and Zn were mainly concentrated in the central urban and southeastern areas, while the high value areas for Hg were concentrated in the southwestern and northeastern areas. This showed that industrial emissions and agricultural production activities caused the degree of heavy metal pollution in the soils while traffic emissions aggravated the levels.

Source identification and spatial distribution of metals in soils in a typical area of the lower Yellow River, eastern China

In this study, 234 soil samples were recently collected from Gaoqing County (a typical area of the lower Yellow River) to determine the contents of As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn. Multivariate statistical analyses such as correlation analysis, principal components analysis, and one-way ANOVA were applied to identify the source of metals in the soil. Geostatistical methods were used to analyze the spatial structure and distribution of the metals. The results indicated that the mean contents of all metals exceeded the background value of the lower Yellow River, especially for As, Cu, and Hg (1.23, 1.20, and 1.29 times that of the BV, respectively), indicating that these metals were enriched in the study area to different degrees. The results derived from multivariate analysis suggested that As, Cd, Cr, Cu, Ni, Pb, and Zn were mainly controlled by the combination of human activities and soil parent material, and the human activities included industrial emissions, traffic emissions, and agricultural practices. In addition, Hg mainly originated from anthropogenic inputs, such as textile printing, plastics processing, and petrochemical engineering. The contents of metals in different types of land use and parent materials are clearly different. The mean content for eight elements in urban construction land was significantly higher than that of the other land use types; in addition to Hg, the mean content of the other elements was the highest in the lacustrine deposit. The elements of As, Cd, Cr, Cu, Ni, Pb, and Zn had similar hotspots in the urban area, indicating the significant human influence. In addition, these seven metals showed high values in the southeast lacustrine deposit area. The high-value areas of Hg were concentrated in the southwest and northeast study area, which were consistent with the spatial pattern of the industrial sites.

Do biochars influence the availability and human oral bioaccessibility of Cd, Pb, and Zn in a contaminated slightly alkaline soil?

Different remediation techniques have been used to restore metal-contaminated sites, including stabilizing metals by adding amendments to the soils. This study experimented three biochars, made from wood and miscanthus, cultivated on contaminated and uncontaminated soils, used as amendments at a 2% application rate on a metal-contaminated soil for 9months in laboratory-controlled conditions. The objective was to evaluate whether biochars were able to decrease the availability and human oral bioaccessibility of metals in an alkaline soil. To meet this goal, the modifications of the soil's physicochemical parameters, metal distribution in soil, and human bioaccessibility were evaluated at different sampling times. The results showed that biochar application to the alkaline soil did not always decrease the soil metal availability, which challenges the value of using biochars in already slightly alkaline soils at a low application rate. However, differences in efficiency between the three biochars tested were highlighted. The biochar produced with miscanthus cultivated on uncontaminated soil led to higher soil metal bioaccessibility. Moreover, because of the absence of any increase in soil metal availability with the biochar produced from biomass cultivated on contaminated soil, the use of such biochars can be recommended for the remediation of contaminated soil.

Spatial distribution and sources of heavy metals in natural pasture soil around copper-molybdenum mine in Northeast China

The characterization of the content and source of heavy metals are essential to assess the potential threat of metals to human health. The present study collected 140 topsoil samples around a Cu-Mo mine (Wunugetushan, China) and investigated the concentrations and spatial distribution pattern of Cr, Ni, Zn, Cu, Mo and Cd in soil using multivariate and geostatistical analytical methods. Results indicated that the average concentrations of six heavy metals, especially Cu and Mo, were obviously higher than the local background values. Correlation analysis and principal component analysis divided these metals into three groups, including Cr and Ni, Cu and Mo, Zn and Cd. Meanwhile, the spatial distribution maps of heavy metals indicated that Cr and Ni in soil were no notable anthropogenic inputs and mainly controlled by natural factors because their spatial maps exhibited non-point source contamination. The concentrations of Cu and Mo gradually decreased with distance away from the mine area, suggesting that human mining activities may be crucial in the spreading of contaminants. Soil contamination of Zn were associated with livestock manure produced from grazing. In addition, the environmental risk of heavy metal pollution was assessed by geo-accumulation index. All the results revealed that the spatial distribution of heavy metals in soil were in agreement with the local human activities. Investigating and identifying the origin of heavy metals in pasture soil will lay the foundation for taking effective measures to preserve soil from the long-term accumulation of heavy metals.

Heavy metals in soils and sediments from Dongting Lake in China: occurrence, sources, and spatial distribution by multivariate statistical analysis.

Heavy metal contamination in soils/sediments and its impact on human health and ecological environment have aroused wide concerns. Our study investigated 30 samples of soils and sediments around Dongting Lake to analyze the concentration of As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn in the samples and to distinguish the natural and anthropogenic sources. Also, the relationship between heavy metals and the physicochemical properties of samples was studied by multivariate statistical analysis. Concentration of Cd at most sampling sites were more than five times that of national environmental quality standard for soil in China (GB 15618-1995), and Pb and Zn levels exceeded one to two times. Moreover, Cr in the soil was higher than the national environmental quality standards for one to two times while in sediment was lower than the national standard. The investigation revealed that the accumulations of As, Cd, Mn, and Pb in the soils, and sediments were affected apparently by anthropogenic activities; however, Cr, Fe, and Ni levels were impacted by parent materials. Human activities around Dongting Lake mainly consisted of industrial activities, mining and smelting, sewage discharges, fossil fuel combustion, and agricultural chemicals. The spatial distribution of heavy metal in soil followed the rule of geographical gradient, whereas in sediments, it was significantly affected by the river basins and human activities. The result of principal component analysis (PCA) demonstrated that heavy metals in soils were associated with pH and total phosphorus (TP), while in sediments, As, Cr, Fe, and Ni were closely associated with cation exchange capacity (CEC) and pH, where Pb, Zn, and Cd were associated with total nitrogen (TN), TP, total carbon (TC), moisture content (MC), soil organic matter (SOM), and ignition lost (IL). Our research provides comprehensive approaches to better understand the potential sources and the fate of contaminants in lakeshore soils and sediments.

Comparison of interpolation models for estimating heavy metals in soils under various spatial characteristics and sampling methods

AbstractHeavy metal pollution in soils has become increasingly challenging, especially in developing countries. Estimating the spatial distribution of heavy metals in soils is essential to preventing their build‐up. This article aims to identify the effects of spatial scales, spatial autocorrelation, sampling methods, and proportion on interpolation models in estimating the distribution of heavy metals in soils. Six interpolation models (area‐and‐point kriging, AAPK; inverse distance weighting, IDW; local polynomial interpolation, LP; ordinary kriging, OK; simple kriging, SK; and thin plate spline, TPS), three sampling methods (random, stratified, and systematic sampling), and five sampling proportions (1, 5, 10, 15, and 20%) are considered in this study using sets of simulated data, and the real situation was tested for verification. The results show that, in general, with the increase of spatial autocorrelation or the sampling percentage, the accuracy and stability of different interpolation models gradually increase; however, the various interpolation models have their own specific characteristics and application conditions. The best application conditions of the interpolation models compared with other models under the same situation are summarized and explained in theory. These conclusions have implications for future work.

Distribution of heavy metals in soils and vegetables and health risk assessment in the vicinity of three contaminated sites in Guangdong Province, China

ABSTRACTDue to rapid industrialization and urbanization, human activities like industrial and agricultural production, transportation, aggravate heavy metal pollution in soil and continue to endanger vegetables and human health. In this study, three contaminated areas affected by heavy metal pollution in Guangdong Province were investigated in terms of Cu, Zn, Pb, and Cd concentrations in soil and vegetables. Further analyses of the contamination status and potential risks to the health of residents consuming these vegetables were conducted. Results showed the following average heavy metal concentrations in vegetables and soil: Shaoguan > Guangzhou > Dongguan, indicating that mining has caused massive soil-heavy metal pollution. The heavy metal concentrations and Bioconcentration factors (BCFs) showed the following trend: leaf-vegetables > fruit-vegetables > root-vegetables, and those of vegetable type were as follows: Cd > Zn > Cu > Pb. The Nemero pollution index (PI) of all research region soils and hazard index (HI) exceeded 1. Hence, more attention should be paid to the potential for adverse health effects caused by the consumption of vegetables produced in these sites . Thus, effective measures are encouraged, with a focus on children due to their vulnerability to these heavy metals.

Temporal variations and spatial distributions of heavy metals in a wastewater-irrigated soil-eggplant system and associated influencing factors

Heavy metal pollution in farmlands is highly concerned as crops’ easy-uptake of heavy metal can ultimately affect consumers. In order to offer suggestions on cultivating safe quality vegetable, specifically eggplant which is widely consumed for its nutritional value and antioxidant activity, a field study was undertaken to investigate the temporal variations and spatial distributions of heavy metals in a wastewater-irrigated soil-eggplant system. In the present study, eggplants were planted in the farmlands of Weichuan village (WC) (relatively unpolluted field), Liangzhuang village (LZ) (moderately polluted field) and Minqin village (MQ) (seriously polluted field) to elucidate their temporal uptake processes of heavy metals described by the sigmoid model. Eggplant tissues from severely polluted farmlands were found with higher heavy metal concentrations and lower yields compared with other two groups. What is more, 25 farmlands along the Dongdagou stream (heavy metals polluted stream) were chosen to analyze the spatial distribution of heavy metals in soils and eggplants. Heavy metal concentrations in eggplants decreased with the decline of heavy metal concentrations in soil from upstream (pollution source) to downstream. Moreover, several methods were employed to assess bioavailability of heavy metals in soils. All the bioavailable heavy metals were found in linear positive correlations with heavy metal concentrations. Meanwhile, linear correlations were found between heavy metals in soils and eggplants. At last, redundancy analysis was used to investigate the effects of soil properties (pH, organic matter and texture of soils) and heavy metals on eggplants’ uptake. The results indicated that soil heavy metals had a dominant impact on their accumulations in eggplant fruit, with a variance contribution of 78.0%, while soil properties had a regulatory effect, with a variance contribution of 5.2%.

Ecological risk assessment from the perspective of soil heavy metal accumulations in Xiamen city, China

ABSTRACTContamination of soils by heavy metals is of rising concern in many cities in China undergoing rapid urbanization. Here, we evaluate the severity of soil contamination by four heavy metals (arsenic, chromium, copper, and lead) at 146 urban and suburban sites within the city of Xiamen, Fujian, China. A multivariate regression model was proposed and developed to simulate heavy metals accumulation in urban and suburban soils, to identify the concentration and spatial distribution of heavy metals in soils, and to assess ecological risks by 2020. Results showed that, overall, Xiamen soils should be subject to low ecological risks due to heavy metals contamination by 2020, the ecological risks for urban soils were greater than suburban soils, nearly half of Xiamen soils are at moderate ecological risks, and many suburban soils experience low ecological risks. The methods demonstrate the potential to predict future ecological risks from heavy metals contamination which could inform pollution prevention and control measures.

Heavy Metals on Technogenic Objects of Mining and Processing Enterprises of the Kryvyi Rig Basin

The goal of the paper is to determine and explain the patterns of distribution of heavy metals in the territories of ore mining and processing enterprises in Kryvyi Rig and to substantiate the legitimacy of applying the method of semiquantitative atomic emission spectral analysis in such studies. Methodology. In the course of the study, various methods of spectral analysis (semiquantitative atomic emission and atomic absorption using 0.5 M HCl and 2 M HNO3) were used in the analysis of soil contamination, and their comparison was made. Results. The content and distribution of heavy metals in soils at the sites of mining and processing enterprises depends primarily on the share of different sedimentary material in them. These are: material of the weathering crust of granites and rocks of greenstone belts of the Middle Dnieper, as well as rocks of the Kryvyi Rig series; products of iron ore beneficiation at mining and processing enterprises and sediments formed during discharge of highly mineralized mine and industrial waters of enterprises; material of slags and smokes of metallurgical enterprises, introduced by the wind; products of domestic waste treatment. The main sources of heavy metals in the soils of the Kryvyi Rig are slags and smokes of metallurgical enterprises. Such a source cannot be the sludge of processing enterprises because of the low content of impurity elements in iron banded formations, including heavy metals. When heavy metals fall onto the soil, their redistribution occurs under the influence of wind and atmospheric precipitation, with the transfer and accumulation of clay-scale particles, the main concentrators of heavy metals, into the lower places of the relief. In general, this leads to the dispersion of heavy metals in soils. Scientific novelty. The factors of geochemical migration of heavy metals within the local geochemical arenas of ore mining and processing enterprises are determined. Practical significance. The educed conformities to law of migration of heavy metals open possibility of more exact prognosis of their distribution in soils on the objects of mining and processing enterprises.

Expected impacts of active mining on the distribution of heavy metals in soils around Iludun-Oro and its environs, Southwestern Nigeria

This present study is aimed at evaluating the level of environmental degradation and potential ecological risk in soils around an active (tantalum-niobium) mining site of Iludun-Oro, southwestern N...

Comparision of Ecological Risk Assessment Based on the Total Amount and Speciation Distribution of Heavy Metals in Soil:A Case Study for Longyan City, Fujian Province

A total of 110 topsoil samples and 61 crop samples along the Lantian-Yangdong Villages were collected in Shizhong, Longyan City. The total amount and speciation of heavy metals(Pb, Cd, As) in soil and crops were determined. The characteristics of the absorption of heavy metals by specific crops in the study area were analyzed, and a new method of risk assessment based on the heavy metal speciation and its bioavailability was established by statistical analysis. This new method was used to evaluate the soil ecological risk and to compare it with the traditional method of potential ecological risk index (RI). The results indicated that the Lantian-Yangdong Villages were located in an area where Pb, Cd, and As mainly originate from the natural soil parent material with weak human disturbance. There was no significant Pb or As pollution in the whole region. Cd was the main pollutant with low pollution intensity. Four types of biological components except for the residual form followed the order of Cd(53.28%) > Pb(43.28%) > As(30.71%). Correlation and regression analyses of total metal concentrations, heavy metal speciation, and crop uptake in the study area showed that the correlations between the total amount of heavy metals and the ion exchange state, carbonate state, and other active forms were low; the results even showed nonlinear relationships between those variables.The ion exchange state had the greatest effect on the absorption of Pb, Cd, and As by coix seed and rice. From the perspective of bioavailability, the new method based on the heavy metal speciation was more accurate than the traditional method based on the total amount of heavy metals.

Shannon–Weaver index as an integrated indicator of metal differentiation in soil and plant samples

The degree of contrast (differentiation) in the distribution of metals in background and contaminated soils is one of the most important geochemical indicators. The Shannon–Weaver index (H) can be a suitable criterion for the distribution of metals in soil and plant samples. A procedure for calculating the Shannon–Weaver index is described. An index scale of five gradations, from no differentiation (Hrel = 1.0–0.9) to very high differentiation (Hrel = 0.3–0.1), is proposed. The background soils in different regions of Russia have low or even no differentiation of metals. Aerial pollution of soils with heavy metals appreciably increases the degree of metal differentiation, especially near the source of pollution. The parameter value decreases with increasing distance from the pollution source, probably due to the mechanical dilution of dust in the large soil volume.

Prediction of soil cadmium distribution across a typical area of Chengdu Plain, China

A suitable method and appropriate environmental variables are important for accurately predicting heavy metal distribution in soils. However, the classical methods (e.g., ordinary kriging (OK)) have a smoothing effect that results in a tendency to neglect local variability, and the commonly used environmental variables (e.g., terrain factors) are ineffective for improving predictions across plains. Here, variables were derived from the obvious factors affecting soil cadmium (Cd), such as road traffic, and were used as auxiliary variables for a combined method (HASM_RBFNN) that was developed using high accuracy surface modelling (HASM) and radial basis function neural network (RBFNN) model. This combined method was then used to predict soil Cd distribution in a typical area of Chengdu Plain in China, considering the spatial non-stationarity of the relationships between soil Cd and the derived variables based on 339 surface soil samples. The results showed that HASM_RBFNN had lower prediction errors than OK, regression kriging (RK) and HASM_RBFNNs, which didn’t consider the spatial non-stationarity of the soil Cd-derived variables relationships. Furthermore, HASM_RBFNN provided improved detail on local variations. The better performance suggested that the derived environmental variables were effective and HASM_RBFNN was appropriate for improving the prediction of soil Cd distribution across plains.

Importance of lithology in defining natural background concentrations of Cr, Cu, Ni, Pb and Zn in sedimentary soils, northeastern Brazil

The sedimentary basins of Recôncavo and Tucano, Bahia, represent the most important Brazilian Phanerozoic continental basin system, formed during fracturing of Gondwana. The northern basin of Tucano has a semiarid climate (Bsh) while the southern basin of Recôncavo has a tropical rainforest climate (Af). The aim of this study was to determine the distribution of trace metals in soils derived from various sedimentary rocks and climates. Soils were collected at 30 sites in 5 geological units at 0–20 cm and 60–80 cm deep under native vegetation. Physical and chemical attributes (particle size distribution, pH, Al, exchangeable bases, organic matter) were determined, as well as the pseudo-total concentrations (EPA 3050 b) and the total concentrations (X-ray fluorescence) of Cr, Cu, Ni, Pb and Zn. The concentrations of metals were overall correlated to soil texture, according to lithologic origin. Shales resulted in Vertisols 30.4 (Zn), 27.2 (Ni), 16.9 (Cu), 7.5 (Cr) and 2.5 (Pb) times more concentrated than Arenosols derived from the sandstones. High Cr and Ni values in clay soils from shales were attributed to diffuse contamination by erosion of mafic rocks of the Greenstone Belt River Itapicuru (from 3 km northwest of the study area) during the late Jurassic. Tropical rainforest climate resulted in a slight enrichment of Pb and Cr, and Ni had the higher mobility during soil formation (enrichment factor up to 6.01). In conclusion, the geological environment is a much more controlling factor than pedogenesis in the concentration of metals in sedimentary soils.

Comparative study of heavy metals distribution in soil, forage, blood and milk

Heavy metals contamination is a global issue and is a severe threat to living organisms. Present study was designed to analyze heavy metals distribution in soil, forage, blood and milk from Livestock station, Khizerabad, Sargodha, Pakistan. Statistical analysis was performed to access the variation in metals concernments in different types of samples as well as variation among sampling seasons. The concentration of heavy metals varied significant (P<0.05) seasonally (summer and winter) as well as among sample types (soil, forage, blood and milk). The Ni mean concentration was recorded in the range of 1.6–64.0mgkg−1 in soil, 0.93–10.26mgL−1 in blood and 0.93–10.26mgL−1 in milk sample and similar trend was observed in case of Co, Cd, Cr and Pb. Concentration of Cr in soil, forage, blood and milk was recorded within the permissible limits, whereas Co and Cd contents were beyond the permissible limits. Pb and Ni contents were within the permissible limits in soil and forage samples. In comparison to previous study conducted in adjoining areas, it was observed that the heavy metals in the environment have been increased, which might be serious threat to the soil, environmental and livings organisms.

Contamination and spatial distribution of heavy metals in soil of Xiangxi River water-level-fluctuating zone of the Three Gorges Reservoir, China

ABSTRACTThe Three Gorges Reservoir is the largest hydroelectric project in China. It forms water-level-fluctuating (WLF) zones with a water level difference which can reach 30 m and a total area of 349 km2 along the Yangtze River. To determine the pollution level and spatial distribution of heavy metals in WLF regions, Xiangxi River (XXR), the largest first-order tributary, was selected as the study area. Both single-factor and multi-factor evaluation methods were employed to assess the contamination indices of heavy metals in soil. The results showed that the pollution degree for sampling sites varied from slight to moderate pollution levels, where 64% were in slight pollution degree and 4% were in moderate pollution degree. Approximately 68% of the sites were polluted. The ranking of 6 different kinds of heavy metals according to pollution degree was Cd > Pb > Cr > Hg > Ni > Cu. While Cd and Pb contributed the most to the pollutions, the contributions of the other four remained minor. Furthermore, a spatial distribution map of the comprehensive contamination index for the XXR basin is generated. The concentrations of heavy metals in sediments along 4 transects showed an overall decreasing trend with increasing elevation.

Distribution of Heavy Metals in Soil of Urban Ecosystems by the Example of the Oryol City

The article deals with the impact of vehicle emissions on the distribution of heavy metals in the soils of urban ecotopes - land urban areas with similar parameters of the biosphere, the technosphere, demographic and urban development factors by the example of the Oryol city.