Research on the Morphological of Lead and Zinc in the Smelting Slag

2015 ◽  
Vol 1088 ◽  
pp. 200-205
Author(s):  
Lin Yu ◽  
Dong Wei Li

In this paper analysed the forms of heavy metals (Zn Pb Cd and As) of the Smelting Slag for Lead and Zinc,using BCR sequential extraction. Different chemical morphological of heavy metals have different activity and harmfulness. Migration and Utilization of heavy metals were decided by the existent form of heavy metals in the soil,which influenced Bioactivity and Toxicity. The results show that the main forms of Zn and Cd are Oxidizable and Residual fraction, and Pb mainly occurred in Oxidizable and Reducible fraction. however, As mainly occurred in Residual fraction, which the percentage of reachs 99.56%. According to the percentage of fractions extracted in total content (As is 0.44%, Zn is 14.7%, Pb is 85.98%, Cd is 48.86%),the latent ecological risk of heavy metals varied in the descending order of,Pb Cd Zn and As.

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 684
Author(s):  
Hee Won Son ◽  
Sun Hee Shim ◽  
Haeseong Oh ◽  
Jung Hyun Choi

In this study, the concentrations and characteristics of copper (Cu), zinc (Zn), and lead (Pb) contamination in sediment samples were investigated using aqua regia extraction and Tessier’s five-step sequential extraction. Based on the concentration of metals, the influence of the Hapcheon-Changnyeong weir on sediments in the Nakdong River was assessed. The origins of the contaminants, their bioavailability, and their mobility were determined using sequential extraction. Greater concentrations of heavy metals were found in samples collected closer to the weir. The largest proportion of Cu was identified in the residual fraction based on sequential extraction, whereas Zn was predominantly found in the reducible fraction. Iron-manganese in the reducible fraction of Zn has the potential to leach back to the water body. In addition, the combined concentration of fractions 1 and 2 of Cu comprised more than 20% of total amount that still has potential to affect the water quality. The results of this study were compared with existing sediment standards set out by the NIER (National Institute of Environmental Research), Canada, and US EPA (United States Environmental Protection Agency) guidelines, as well as the risk assessment code (RAC). The concentrations of heavy metals exceeded the standards set by the Canadian guideline by up to four times in particular samples, highlighting the need for continual monitoring.


2018 ◽  
Vol 44 ◽  
pp. 00116 ◽  
Author(s):  
Kamila Mizerna

The paper presents the results of heavy metals mobility obtained by sequential extraction method and leaching test. Heavy metals in solid waste material occur in different forms and phases that differ in terms of the toxicity, mobility and bioavailability. The sequential extraction analysis is widely used in order to predict the behaviour of heavy metals in a solid material. The sequential extraction methods involve a gradual separation of metals in various forms by means of specific extractants. The material used in the research applied bottom ash derived from households. The results of heavy metals concentrations (Cd, Pb, Ni, Cr, Cu, Zn) in extractable forms and total content in waste were presented. The five forms of heavy metals were determined. The concentrations of heavy metals were analyzed by FAAS. The lowest concentrations of analyzed heavy metals were determined in the exchangeable form. The author observed that the particular elements occurred mainly in forms: zinc and cadmium associated with carbonates, lead and copper in the organic and residual form, chromium and nickel in the residual form. Heavy metals in the residual fraction do not pose a possible environment hazard. The application of speciation analysis of heavy metals in bottom ash provide the means to assess the content of dissoluble forms of metals in water relative to their total content. This information is useful in assessing the migration capabilities of heavy metal ions from waste to the ground-water environment. The potential for the reuse of bottom ash was also discussed in the paper.


2019 ◽  
Vol 24 (1) ◽  
pp. 23
Author(s):  
Lestari Lestari ◽  
Fitri Budiyanto

The assessment of the biological availability of metals is rarely used only by knowing the total concentration of the metal. Therefore, six sediment samples from Muara Angke, Teluk Jakarta were assessed the chemical speciation of heavy metals. This study aims to determine metal speciation using the BCR sequential extraction procedure and to determine metal speciation to evaluate bioavailability in the sediments of Muara Angke, Jakarta Bay. In sediment from Muara Angke, the ability to move sequence of heavy metals studied was Pb>Zn>Cu>Ni. The mostly accumulated in the non-residual fraction of the total concentrations are Cu, Ni, Pb and Zn which indicated that the mobility and anthropogenic inputs of these metals in Muara Angke were quite high. The Risk Assessment Code (RAC) reveal that Zn and Ni at almost station exist in exchangeable and a fraction of carbonate-bound and therefore high-risk category. Most of the Cu at most of the station is in the oxidizable fraction, except a small portion found at all station is in the exchangeable fraction and fraction of carbonate-bound thus posing a low risk for the waters environment. The patterns of Pb speciation show no to low risk to the waters environment. However, metal observations in the waters are necessary because they are persistent and can accumulate which threatening the water environment.


Author(s):  
P. M. Kahara ◽  
J. Murungi ◽  
J. K. Kiptoo ◽  
G. Nyaga

Open dumpsites are one of the main sources of heavy metals and as a result, lots of research has been undertaken on the pseudo-total content of heavy metals in dumpsite soils, but little research on the forms in which they exist. The current research was carried out to determine levels of chromium, lead and cadmium in the various fractions of Dandora dumpsite soil and how they are fractionated in the topsoil and subsoil horizons. Samples were obtained from eight sites with depths of (0-30 cm) and (30-60 cm) for topsoil and bottom soils respectively. The modified Community Bureau of Reference (BCR) sequential extraction procedure was used and metal analysis performed using flame atomic absorption spectrophotometry. The metals (lead, chromium and cadmium) total concentration (µg/g) in the upper soil profile ranged from 42.22 to 1096.21, 38.26 to 180.60 and 11.23 to 44.22 while the lower soil profiles were 54.19 to 239.28, 30.56 to 76.48 and 9.47 to 22.56, respectively. The concentration of lead in various fractions of the upper soil profile followed the order; reducible > oxidisable > residual > exchangeable, while that of chromium was residual > oxidisable > reducible > exchangeable. Cadmium followed the order exchangeable > residual > reducible > oxidisable. The percentage of the metals in non-residual fraction were Pb (78%), Cr (58.7%) and Cd (70%). Their mobility factors were (Pb) 39.7 (Cr) 7.75 and (Cd) 5.02 in the upper soil profiles. Thus, the results suggest that Dandora dumpsite is highly polluted with the selected heavy metals.


Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 891
Author(s):  
Qian Zhang ◽  
Guilin Han ◽  
Xingliang Xu

Human agricultural activities have resulted in widespread land degradation and soil contamination in the karst areas. However, the effects of reforestation after agricultural abandonment on the mobility risks and contamination of heavy metals have been rarely reported. In the present study, six soil profiles were selected from cropland and abandoned cropland with reforestation in the Puding karst regions of Southwest China. The Community Bureau of Reference (BCR) sequential extraction method was used to evaluate the compositions of different chemical fractions of soil heavy metals, including Fe, Mn, Cr, Zn, Ni, and Cd. The total contents of Cr, Ni, Zn, Cd, and Mn in the croplands were significantly higher than those in the abandoned croplands. For all soils, Cr, Ni, Zn, and Fe were mainly concentrated in the residual fractions (>85%), whereas Mn and Cd were mostly observed in the non-residual fractions (>65%). The non-residual fractions of Cd, Cr, Ni, and Zn in the croplands were higher than those in the abandoned croplands. These results indicated that the content and mobility of soil heavy metals decreased after reforestation. The individual contamination factor (ICF) and risk assessment code (RAC) showed that Cd contributed to considerable contamination of karst soils. The global contamination factor (GCF) and potential ecological risk index (RI) suggested low contamination and ecological risk of the investigated heavy metals in the croplands, moreover they can be further reduced after reforestation.


Author(s):  
Vinay Kumar ◽  
Pokhraj Sahu ◽  
Markandeya

Abstract The geochemical fractionation of toxic heavy metals Cd, Pb, Cr, Co, Mn, Ni, Cu, Fe and Zn was investigated in 10 different sites of river bed sediments (up, mid and downstream) of Gomti River at Lucknow city. Sequential extraction technique was used to identify the distribution of trace elements binding in different fractions i.e., exchangeable, carbonate, Fe and Mn oxide, organic matter and residual. Heavy metal concentrations were least at upstream and significantly higher in mid and downstream. Fractionation indicated that dominant metals were bound in residual fraction to the bed sediments except for Cd and Pb which were bound in an equivalent fraction. Geo-accumulation index factor reveals that the enrichment of heavy metals in the bio-available fraction is contributed anthropogenically. Hierarchical cluster analysis also shows the metal pollution load in the river. Risk assessment code of Cd and Ni showed very high risk (ranged from 54.41 to 85.56 and 20.57 to 44.92 respectively) followed by Pb (high risk), Zn, Co (medium risk), Cr, Mn, Cu, Fe (low risk) in Gomti River water. Further, concentrations of Cd and Pb at mid Lucknow were 31 and 75%, high enough to pose a substantial risk to the environment.


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