Assessment of a heavy metals‐contaminated site using sequential extraction, TCLP, and risk assessment techniques

1995 ◽  
Vol 4 (4) ◽  
pp. 311-325 ◽  
Author(s):  
Ian Phillips ◽  
Lyndsay Chappie
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.


2013 ◽  
Vol 448-453 ◽  
pp. 293-298
Author(s):  
Zheng Gang Gu ◽  
Min Wu ◽  
Ping Ning

The speciation of the heavy metals Cu, Cr, and Pb in surface sediment samples collected from Lugu Lake in China was analyzed by European Community Bureau of Reference (BCR) sequential extraction methods. Heavy metal bioavailability was assessed by risk assessment code. This study demonstrates that BCR sequential extraction methods and risk assessment code can be used as valuable tools to assess heavy metal mobility, bioavailability and eco-toxicity. The distribution of Cu, Cr, and Pb in the surface sediment of Lugu Lake showed that all three metals were mainly present in the reducible fraction. The bioavailability of the heavy metals in the surface sediment was in the order Cu > Cr > Pb.


Author(s):  
Jun-Xian Wang ◽  
Da-Mao Xu ◽  
Rong-Bing Fu ◽  
Jia-Peng Chen

Despite recent studies have investigated the strong influences of smelting activities on heavy metal contamination in the soil environment, little studies have been conducted on the current information about the potential environmental risks posed by toxic heavy metals in smelting contaminated sites. In the present study, a combination of the bioavailability, speciation, and release kinetics of toxic heavy metals in the indigenous zinc smelting contaminated soil were reliably used as an effective tool to support site risk assessment. The bioavailability results revealed that the bioavailable metal concentrations were intrinsically dependent on the types of chemical extractants. Interestingly, 0.02 mol/L EDTA + 0.5 mol/L CH3COONH4 was found to be the best extractant, which extracted 30.21% of Cu, 31.54% of Mn, 2.39% of Ni and 28.89% of Zn, respectively. The sequential extraction results suggested that Cd, Pb, and Zn were the most mobile elements, which would pose the potential risks to the environment. The correlation of metal bioavailability with their fractionation implied that the exchangeable metal fractions were easily extracted by CaCl2 and Mehlich 1, while the carbonate and organic bound metal fractions could be extracted by EDTA and DTPA with stronger chelating ability. Moreover, the kinetic modeling results suggested that the chemical desorption mechanism might be the major factor controlling heavy metal release. These results could provide some valuable references for the risk assessment and management of heavy metals in the smelting contaminated sites.


2021 ◽  
Author(s):  
Yutong Zong ◽  
Qing Xiao ◽  
Zaffar Malik ◽  
Shenggao Lu

Abstract This study evaluated chemical fractions, potential leachability, and bio-accessibility of heavy metals (Cr, Cu, Cd, Ni, Pb, and Zn) in road dusts from the steel-industrial city (Anshan), Northeastern China. Chemical fractions of heavy metals were determined using Tessier sequential extraction method. The environmental risk assessment was evaluated using short-term extraction tests: TCLP, PBET, and CaCl2. Sequential extraction analysis reveals that Cr and Ni primarily existed in residual form. The non-residual fraction of heavy metals decreased in the order of Zn (average 57.78%)> Cu (39.16%)> Pb (30.73%)≈ Cd (30.67%)> Ni (19.06 %)> Cr (8.7%%). The results showed that Cd, Cu, Zn and Pb, which were extremely concentrated in potentially mobile fractions, had highly potential environmental risks. The mobility of Cd and Zn was usually higher than those of Cr, Cu, Pb and Ni, which means that Cd and Zn have higher hazardous to ecosystem. The order of bioavailability identified by PBET method was generally Zn>Cd>Pb>Ni>Cu>Cr. There was a significantly relationship between PBET, TCLP-test and bioavailable parts (F1+F2+F3+F4, SUM4) of sequential extraction, respectively. Multiple linear regression analysis indicated that toxicity and bioavailability of heavy metals were not only depended on RDs properties, but also lied on the total heavy metals.


2019 ◽  
Vol 18 (1) ◽  
pp. 18-27
Author(s):  
Yujin Oh ◽  
YoonDeok Han ◽  
Yunjae Kim ◽  
Sunghyeon Jung ◽  
Wonhee Jung ◽  
...  

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