Integrating hierarchical bioavailability and population distribution into potential eco-risk assessment of heavy metals in road dust: A case study in Xiandao District, Changsha city, China

Self Cite

Abstract:Competitive adsorption of Pb 2+ , Cd 2+ and Zn 2+ ions on sodium dodecyl sulfate (SDS) in binary mixtures were investigated compared with non-competitive adsorption in the unitary metal solution in micellar-enhanced ultrafiltration at a temperature of 25 • C. Mutual interference effects were investigated based on the removal rate, the Langmuir Competitive Model (LCM) and equilibrium adsorption capacity ratios, q e /q m , which indicated the presence of other metal ions. The results indicated that the removal rate and adsorption capacity of Pb 2+ were higher than that of the other metal ions in unitary and binary systems. The effects on SDS micelles for Cd-Pb and Zn-Pb combinations were found to be antagonistic. However, it was a favorable effect for the Cd-Zn combination, and the metal ions sorption followed the order: Pb 2+ > Cd 2+ > Zn 2+ . The behavior of non-competitive and competitive adsorption for Cd 2+ and Zn 2+ in a single system and in the presence of Pb 2+ were well described by LCM. Moreover, the LCM showed poor fitting to non-competitive and competitive adsorption of Pb 2+ in a single solution and in the presence of Cd 2+ or Zn 2+ . In conclusion, the removal of Pb 2+ in the presence of Zn 2+ or Cd 2+ showed greater efficacy than that of Cd 2+ or Zn 2+ in the presence of Pb 2+ .

Section: Introductionmentioning

confidence: 99%

Non-Competitive and Competitive Adsorption of Pb2+, Cd2+ and Zn2+ Ions onto SDS in Process of Micellar-Enhanced Ultrafiltration

Feng

et al. 2018

Self Cite

“…HIs for the studied metals in Central China were higher for children than for adults [128]. In particular, the HQs for children through ingestion were averaged at 7.14 times higher than those for adults, with dermal contact 4.92 times higher and inhalation 1.36 times higher [27]. The HQ of the three exposure pathways for both children and adults in Central China decreased in the following order: ingestion > dermal contact > inhalation, which was similar to other reports [121,129,130].…”

Section: Human Health Assessment Of Children and Adults In Central Chinamentioning

confidence: 84%

“…Owing to the fact that the spatial distribution of metals is a useful way to identify hotspot areas with high metal concentrations [27,128], the corresponding distribution maps were produced and are shown in Figure 2. The percentage of high Cu concentrations decreased in the order of Hunan Province > Henan Province > Hubei Province, which was similar to Cd, Zn, Pb and Hg.…”

Section: Spatial Distribution Patterns Of Toxic Metals In Central Chinamentioning

confidence: 99%

Spatial Characteristics, Health Risk Assessment and Sustainable Management of Heavy Metals and Metalloids in Soils from Central China

Cai

Zhang

2018

Self Cite

Abstract:The contents of seven toxic metals (Cu, Cr, Cd, Zn, Pb, Hg and As) in soils from Central China, including Henan Province, Hubei Province and Hunan Province, were collected from published papers from 2007 to 2017. The geoaccumulation index, health risk assessment model and statistics were adopted to study the spatial contamination pattern, to assess the human health risks and to identify the priority control pollutants. The concentrations of soil metals in Central China, especially Cd (1.31 mg/kg), Pb (44.43 mg/kg) and Hg (0.19 mg/kg), surpassed their corresponding background values, and the I geo values of Cd and Hg varied the most, ranging from the unpolluted level to the extremely polluted level. The concentrations of toxic metals were higher in the southern and northern parts of Central China, contrasting to the lowest contents in the middle parts. For non-carcinogenic risk, the hazard index (HI) values for the children in Hubei Province (1.10) and Hunan Province (1.41) exceeded the safe level of one, with higher health risks to children than adults, and the hazard quotient (HQ) values of the three exposure pathways for both children and adults in Central China decreased in the following order: ingestion > dermal contact > inhalation. For carcinogenic risk (CR), the CR values for children in Hubei Province (2.55 × 10 −4 ), Hunan Province (3.44 × 10 −4 ) and Henan Province (1.69 × 10 −4 ), and the CR for adults in Hubei Province (3.67 × 10 −5 ), Hunan Province (4.92 × 10 −5 ) and Henan Province (2.45 × 10 −5 ) exceeded the unacceptable level (10 −4 ) and acceptable level (10 −6 ), respectively. Arsenic (As) appeared to be the main metalloid for both children and adults causing the high carcinogenic risk. For sustainable development in Central China, special attention should be paid to Cd, Hg, Cr, Pb and As, identified as the priority control soil metals. Importance should also be attached to public education, source control, and the remediation of the highly contaminated soils, especially in the areas where it can endanger the groundwater. Furthermore, it is necessary to appropriately adjust the industrial structure and cooperate more to form a complete economic zone.

“…First, although network inverse distance weighted interpolation outperformed planar interpolation methods, identifying a reach as contaminated should not merely be based on the result of interpolation results. It is suggested that the spatial distribution of heavy metal contents is largely influenced by the natural environment and human activities [2], which should be considered in subsequent analysis. In order to acquire a more reliable pollution assessment, additional sampling at the uncertainty region is necessary.…”

Section: Discussionmentioning

confidence: 99%

“…Heavy metals are ubiquitous in the environment, as a result of both natural and anthropogenic activities [1,2]. Over the past few decades, heavy metal pollution in aquatic ecosystems is a worldwide environmental problem that has received increasing attention because of its adverse effects on environment sustainability and human health [3][4][5][6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Measuring Spatial Distribution Characteristics of Heavy Metal Contaminations in a Network-Constrained Environment: A Case Study in River Network of Daye, China

Wang

Nie

2017

Abstract:Measuring the spatial distribution of heavy metal contaminants is the basis of pollution evaluation and risk control. Considering the cost of soil sampling and analysis, spatial interpolation methods have been widely applied to estimate the heavy metal concentrations at unsampled locations. However, traditional spatial interpolation methods assume the sample sites can be located stochastically on a plane and the spatial association between sample locations is analyzed using Euclidean distances, which may lead to biased conclusions in some circumstances. This study aims to analyze the spatial distribution characteristics of copper and lead contamination in river sediments of Daye using network spatial analysis methods. The results demonstrate that network inverse distance weighted interpolation methods are more accurate than planar interpolation methods. Furthermore, the method named local indicators of network-constrained clusters based on local Moran' I statistic (ILINCS) is applied to explore the local spatial patterns of copper and lead pollution in river sediments, which is helpful for identifying the contaminated areas and assessing heavy metal pollution of Daye.