scholarly journals Soil Heavy Metal Distribution with Depth around a Closed Landfill and Their Uptake by Datura stramonium

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Peace Makuleke ◽  
Veronica M. Ngole-Jeme
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Transfer Coefficient ◽  
Datura Stramonium ◽  
Metal Transfer ◽  
Control Site ◽  
Soil Samples ◽  
Metal Enrichment ◽  
Soil Heavy Metal ◽  
Heavy Metal Enrichment

Landfills are major sources of environmental pollution. This study evaluated heavy metal concentrations in soils and plants around the closed Lumberstewart landfill in Bulawayo, Zimbabwe, to determine the pollution potential of a closed landfill and the risks they present to plants growing in this environment and surrounding communities. Soil samples were collected at depths of 0–30 cm, 30–60 cm, and 60–90 cm around the landfill and at a control site and characterized for various properties and concentrations of Cd, Cu, Cr, Fe, Ni, and Zn. Samples of Datura stramonium, collected from the same sites where soil samples were collected, were also analyzed for the same heavy metals. The soils were sandy, mostly acidic (5.01 < pH < 7.65) with low organic matter content (<2%) and cation exchange capacity (<15 meq/100 g). These properties varied with depth around the landfill. Heavy metals concentrations in the soils and Datura stramonium followed the order Fe > Zn > Cu > Cr > Ni > Cd with samples from around the landfill having higher concentrations than samples from the control site. Soil heavy metal enrichment was highest at a depth of 30–60 cm. Pollution load index (PLI) values indicated that all sites around the landfill were polluted (PLI > 1). Heavy metal transfer coefficient in Datura stramonium ranged between 0.0 and 209 with <60% of the variation observed in heavy metal transfer coefficient in Datura stramonium explained by the extent of heavy metal enrichment in the soils. More than 20 years after closure of the landfill, there are indications that leachate migration may still be going on around the landfill. Monitoring of environments around closed landfills needs to be ongoing to mitigate negative impacts on humans and the environment.

scholarly journals Evaluation and Ecological Risk Assessment of Selected Heavy Metal Pollution of Soils and Amaranthus cruentus and Telfairia occidentalis Grown Around Dump Site in Chanchaga Minna, Niger State, Nigeria

2019 ◽  
pp. 1-16 ◽  
Author(s):  
Oguh C. Egwu ◽  
Uzoefuna C. Casmir ◽  
Ugwu C. Victor ◽  
Ubani C. Samuel ◽  
Musa A. Dickson ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Risk Assessment ◽  
Heavy Metal ◽  
Ecological Risk ◽  
Control Site ◽  
Soil Samples ◽  
Amaranthus Cruentus ◽  
Dump Site ◽  
Telfairia Occidentalis ◽  
Heavy Metals In Soils

The study investigate a series of selected heavy metal pollution of soil, the extent of their uptake by Telfairia occidentalis and Amaranthus cruentus as well as their ecological risk around dumpsite in Chanchaga Minna, Niger State, Nigeria. Soil samples were collected at 15 cm depth with the aid of soil auger and vegetable samples were collected from dumpsite and other samples with no activities served as control. The soil samples were collected at random and their physicochemical parameters such as pH, total nitrogen, total phosphorus, organic matter, total carbon and exchangeable cations (i.e., K+, Mg2+ and Na+) using a standard method and concentrations of the heavy metals in soils and vegetables, As, Cd, Cr, Cu, Hg and Pb were analyzed using flame Atomic Absorption Spectrometer (AAS). The ecological health risk assessment from the consumption of these vegetables was calculated using standard methods. The result showed a significant (p-value) increase of AC and TO in test soil samples relative to the control soils. The pH of the soil in dumpsite and control site was 5.93, and 7.35 respectively. Mean concentrations of As, Cd, Cr, Cu, Hg and Pb in the dump site were 6.35, 4.84, 6.67, 7.35, 5.72 and 4.96 mg/kg while the control site were 1.18, 0.28, 1.26, 6.83, 1.19 and 3.54 mg/kg respectively which was below the WHO/FAO limits of As (20), Cd (3.0), Cr (100), Cu (100), Hg (2.00) and Pb (50 mg/kg) for soil. The concentrations of As, Cd, Cr, Cu, Hg and Pb recorded in AC dump site were As (6.13), Cd (3.67), Cr (5.37), Cu (4.28), Hg (3.46), and Pb (4.52) and in TO As (5.67), Cd (3.13), Cr (4.67), Cu (3.65), Hg (3.19) and Pb (4.27 mg/kg) which were above the WHO/FAO permissible limits (0.5, 0.20, 0.3, 3.0, 0.1 and 0.3 mg/kg) respectively for edible vegetable. The concentrations of heavy metals in soils and vegetables from the dumpsite soil were significant (p < 0.05) from the controls. The bioaccumulation factor (BAF) for the vegetable showed that they exclude the element from soil. The Hazard Quotient (HQ) and Hazard index (HI) show that there is no harmful effect since the values obtain were not greater than >1. But continuous consumption can accumulate in the food chain especially for children. This study showed that the soils and vegetables within the vicinity of the dumpsites were polluted by heavy metals which can pose health risk. The study also calls for proper waste management practices and policy implementation.

scholarly journals Physicochemical Characteristics and Heavy Metals Contents in Soils and Cassava Plants from Farmlands within Nnamdi Azikiwe University, Awka, Anambra State

2021 ◽  
pp. 37-43
Author(s):  
N. P. Udeh ◽  
A. C. Ikegwuonu ◽  
O. A. Okeke ◽  
C. Obudulu ◽  
K. P. Okafor ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Physicochemical Characteristics ◽  
Mean Value ◽  
Soil Samples ◽  
Metal Enrichment ◽  
Metal Concentrations ◽  
Mean Values ◽  
Metal Levels ◽  
The Mean

Soil samples and cassava tubers collected from farmlands within Nnamdi Azikiwe University, Awka vicinity were analyzed for their heavy metal levels using Atomic Absorption Spectrophotometer (AAS) in order to assess their levels of contamination on the environment as a result of excessive fertilizers and automobile emission. Physiochemical properties of the soil samples were determined using standard methods. The soil pH had a mean value of 6.27 ± 0.07, 6.10 ± 0.06 and 6.57 ± 0.03 respectively indicating that the soils were slightly acidic to neutrality. Total organic carbon and nitrate mean values were 105.20 ± 6.20, 95.75 ± 9.57 and 94.6 ± 2.27 and 138.07 ± 12.09, 149.35 ± 14.25 and 149.20 ± 1.17 respectively showing presence of some organic matters. The mean levels of heavy metals in the soil samples were 0.01 ± 0.01, 0.05 ± 0.03 and 0.05 ± 0.03 for lead (Pb), 0.24 ± 0.16, 0.001 ± 0.001 and 0.001 ± 0.000 for cadmium (Cd) and 0.00 ± 0.00, 0.010 ± 0.006 and 0.001 ± 0.001 for chromium (Cr). These metals levels were in the abundance trend of Pb>Cd> Cr. The mean metal concentrations obtained in the cassava tubers respectively were 0.001 ± 0.001, 0.001 ± 0.001 and 0.005 ± 0.005 for lead (Pb), 0.000 ± 0.000, 0.0003 ± 0.0003 and 0.000 ± 0.000 for cadmium (Cd) and 0.002 ± 0.002, 0.000 ± 0.000 and 0.002 ± 0.002 for chromium (Cr). These metals levels were in the abundance trend of Pb> Cr > Cd. For both the soil and cassava samples, there were no significant variations in the heavy metal concentrations and also in physicochemical parameter except for pH; this showed that there is low heavy metal enrichment in the soils studied. Based on the study, the following heavy metals (Pb, Cd, and Cr) falls within the Codex maximum permissible limits 0.1mg/l or ppm expect soil cadmium in science village which is above the Codex limit. The overall results showed that the farmlands (on soils and cassava tuber) appear to be free from poisoning or some metal enrichment and safe for agricultural purposes and also safe for human health and consumption.

scholarly journals Estimation of Soil Heavy Metal Content Using Hyperspectral Data

2019 ◽  
Vol 11 (12) ◽  
pp. 1464 ◽  
Author(s):  
Zhenhua Liu ◽  
Ying Lu ◽  
Yiping Peng ◽  
Li Zhao ◽  
Guangxing Wang ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Content ◽  
Regional Scale ◽  
Soil Samples ◽  
Hyperspectral Data ◽  
Heavy Metal Content ◽  
Soil Heavy Metal ◽  
Relationship Of ◽  
The Relationship

Quickly and efficiently monitoring soil heavy metal content is crucial for protecting the natural environment and for human health. Estimating heavy metal content in soils using hyperspectral data is a cost-efficient method but challenging due to the effects of complex landscapes and soil properties. One of the challenges is how to make a lab-derived model based on soil samples applicable to mapping the contents of heavy metals in soil using air-borne or space-borne hyperspectral imagery at a regional scale. For this purpose, our study proposed a novel method using hyperspectral data from soil samples and the HuanJing-1A (HJ-1A) HyperSpectral Imager (HSI). In this method, estimation models were first developed using optimal relevant spectral variables from dry soil spectral reflectance (DSSR) data and field observations of soil heavy metal content. The relationship of the ratio of DSSR to moisture soil spectral reflectance (MSSR) with soil moisture content was then derived, which built up the linkage of DSSR with MSSR and provided the potential of applying the models developed in the laboratory to map soil heavy metal content at a regional scale using hyperspectral imagery. The optimal relevant spectral variables were obtained by combining the Boruta algorithm with a stepwise regression and variance inflation factor. This method was developed, validated, and applied to estimate the content of heavy metals in soil (As, Cd, and Hg) in Guangdong, China, and the Conghua district of Guangzhou city. The results showed that based on the validation datasets, the content of Cd could be reliably estimated and mapped by the proposed method, with relative root mean square error (RMSE) values of 17.41% for the point measurements of soil samples from Guangdong province and 17.10% for the Conghua district at the regional scale, while the content of heavy metals As and Hg in soil were relatively difficult to predict with the relative RMSE values of 32.27% and 28.72% at the soil sample level and 51.55% and 36.34% at the regional scale. Moreover, the relationship of the DSSR/MSSR ratio with soil moisture content varied greatly before the wavelength of 1029 nm and became stable after that, which linked DSSR with MSSR and provided the possibility of applying the DSSR-based models to map the soil heavy metal content at the regional scale using the HJ-1A images. In addition, it was found that overall there were only a few soil samples with the content of heavy metals exceeding the health standards in Guangdong province, while in Conghua the seriously polluted areas were mainly distributed in the cities and croplands. This study implies that the new approach provides the potential to map the content of heavy metals in soil, but the estimation model of Cd was more accurate than those of As and Hg.

scholarly journals Environmental Background Values and Ecological Risk Assessment of Heavy Metals in Watershed Sediments: A Comparison of Assessment Methods

Water ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 51
Author(s):  
Jianbo Liao ◽  
Xinyue Cui ◽  
Hai Feng ◽  
Shangkun Yan
Keyword(s):  
Heavy Metals ◽  
Risk Assessment ◽  
Heavy Metal ◽  
Risk Index ◽  
Aquatic Organisms ◽  
Total Content ◽  
Metal Enrichment ◽  
Background Values ◽  
Positive Linear Correlation ◽  
Heavy Metal Enrichment

The distribution and assessment of heavy metal pollution in sediments have been extensively studied worldwide. Risk assessment methods based on total content, background values, and sediment quality guidelines are widely applied but have never been compared. We systematically sorted out these evaluation methods, obtained evaluation results using actual monitoring data, and compared their applicability. The results showed that the background values of different metals are significantly different, which may depend on their mobility. Geoaccumulation index (Igeo) and enrichment factor (EF) values invariably decreased with the increase of background values for individual heavy metal enrichment risk assessment. Compared with EF, Igeo also showed a significant positive linear correlation with heavy metal content. Pollution load index (PLI), modified contamination degree (mCd), and potential ecological risk index (RI) showed significant differences in response to background values and evaluation levels for the comprehensive risk of heavy metal enrichment, but their distribution trends along with the sampling points were basically identical. Toxic risk index (TRI), mean ERM quotient (mERMQ), and contamination severity index (CSI) were used to evaluate the damage degree of complex heavy metals to aquatic organisms and shared a similar whole-process distribution trend. The modified hazard quotient (mHQ), which is used to evaluate the toxicity of a single heavy metal to aquatic organisms, showed a significant positive linear correlation with the total content of each heavy metal, indicating that the toxic effect on organisms can be predicted through the direct monitoring. The results of this study have important guiding significance for the selection of evaluation methods for heavy metal pollution in sediments.

scholarly journals Heavy metal enrichment in the riparian sediments and soils of the Three Gorges Reservoir, China

2015 ◽  
Vol 367 ◽  
pp. 244-250 ◽  
Author(s):  
Q. Tang ◽  
Y. Bao ◽  
X. He ◽  
A. Wen
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Three Gorges Reservoir ◽  
Riparian Zone ◽  
Three Gorges ◽  
Metal Enrichment ◽  
Vertical Transfer ◽  
The Three Gorges ◽  
Riparian Soils ◽  
Heavy Metal Enrichment

Abstract. The Three Gorges Reservoir encompasses a riparian zone with a vertical height of 30 m and a total area of 349 km2 that has been subjected to alternate inundation and exposure due to regular impoundment. Sedimentation on the riparian landforms constitutes an important pathway for riverine contaminant redistribution. In an attempt to understand heavy metal enrichment since water inundation, riparian sediments and soils were sampled along five transects in a typical riparian zone composed of cultivated bench terraces in the middle reaches. Heavy metals (Cr, Ni, Cu, Zn, As, Cd and Pb) were determined to characterize the lateral distribution and vertical transfer ratio. The results indicated that all heavy metals were enriched to varying extents both in the riparian sediments and soils, compared with regional background contents in soils and the reference levels in sediments. However, heavy metal levels in the riparian sediments were generally higher than those in the riparian soils, while those in the upper riparian soils (0–5 cm) were overall slightly higher than those in the lower riparian soils (5–10 cm). There was a decreasing trend of heavy metal contents with increasing elevation. The elevated levels of heavy metals in the riparian sediments may be attributed to sediment yields from upstream anthropogenic sources, especially during major rainstorms in the wet season when large loads of contaminated sediment may be produced from diffuse source areas. Heavy metals can also be adsorbed to pure sediment in the course of mobilization or after deposition. Considering that the riparian soils are local weathering products without mobilization, the enrichment of heavy metals may principally be ascribed to chemical adsorption from dissolved fractions or vertical transfer from overlaid sediments. Heavy metal enrichment may further be affected by the specific type of hydrologic regime such that relatively long flooding duration caused by water impoundment and natural floods was responsible for the relatively higher levels of heavy metals in the lower portions of the riparian zone.

scholarly journals A search for heavy-metal stars: abundance analyses of hot subdwarfs with Subaru★

2019 ◽  
Author(s):  
Naslim N ◽  
C S Jeffery ◽  
V M Woolf
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
High Surface ◽  
Surface Enrichment ◽  
Metal Enrichment ◽  
Small Subgroup ◽  
Show Evidence ◽  
Hot Subdwarfs ◽  
Chemical Peculiarity ◽  
Heavy Metal Enrichment

Abstract The discovery of extremely zirconium- and lead-rich surfaces amongst a small subgroup of hot subdwarfs has provoked questions pertaining to chemical peculiarity in hot star atmospheres and about their evolutionary origin. With only three known in 2014, a limited search for additional ‘heavy-metal’ subdwarfs was initiated with the Subaru telescope. Five hot subdwarfs having intermediate to high surface enrichment of helium were observed at high-resolution and analyzed for surface properties and abundances. This paper reports the analyses of four of these stars. PG 1559+048 and FBS 1749+373, having only intermediate helium enrichment, show strong lines of triply ionized lead. PG 1559+048 also shows a strong overabundance of germanium and yttrium. With more helium-rich surfaces, Ton 414 and J17554+5012, do not show evidence of heavy-metal enrichment. This limited survey suggests that extreme enrichment of ‘heavy metals’ by selective radiative levitation in hot subdwarf atmospheres is suppressed if the star is too helium-rich.

scholarly journals Chemical Properties of Heavy Metal-Contaminated Soils from a Korean Military Shooting Range: Evaluation of Pb Sources Using Pb Isotope Ratios

2021 ◽  
Vol 11 (15) ◽  
pp. 7099
Author(s):  
Inkyeong Moon ◽  
Honghyun Kim ◽  
Sangjo Jeong ◽  
Hyungjin Choi ◽  
Jungtae Park ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Contaminated Soils ◽  
Management Strategies ◽  
Chemical Properties ◽  
Heavy Metal Concentration ◽  
Soil Samples ◽  
Shooting Range ◽  
Geochemical Properties ◽  
Mineral Phases

In this study, the geochemical properties of heavy metal-contaminated soils from a Korean military shooting range were analyzed. The chemical behavior of heavy metals was determined by analyzing the soil pH, heavy metal concentration, mineral composition, and Pb isotopes. In total, 24 soil samples were collected from a Korean military shooting range. The soil samples consist of quartz, albite, microcline, muscovite/illite, kaolinite, chlorite, and calcite. Lead minerals, such as hydrocerussite and anglesite, which are indicative of a transformation into secondary mineral phases, were not observed. All soils were strongly contaminated with Pb with minor concentrations of Cu, Ni, Cd, and Zn. Arsenic was rarely detected. The obtained results are indicated that the soils from the shooting range are contaminated with heavy metals and have evidences of different degree of anthropogenic Pb sources. This study is crucial for the evaluation of heavy metal-contaminated soils in shooting ranges and their environmental effect as well as for the establishment of management strategies for the mitigation of environmental risks.

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