scholarly journals Sequential extraction and risk assessment of pollutants from one major tributary of the Ganga

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.

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.


Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 2024
Author(s):  
Sanja Sakan ◽  
Stanislav Frančišković-Bilinski ◽  
Dragana Đorđević ◽  
Aleksandar Popović ◽  
Sandra Škrivanj ◽  
...  

This study investigated the quality of Kupa River sediment using sequential extraction, ecological risk, and contamination indexes (Risk assessment code, Index of geoaccumulation, Enrichment factor, Ecological risk factor, Ecological risk index), determination of magnetic susceptibility of sediments, and statistical methods. The BCR sequential extraction technique was used for evaluating various element-binding forms. Most of the elements were considered to be immobile due to the high availability in the residual fraction. Lead was present mainly in the reducible fraction, while more easily mobile and bioavailable forms were predominant for cadmium and barium. Sediment samples from the river catchment exhibited low ecological risk. The most toxic element, Cd, is the main contributor to the total potentially ecological risk. Increased values of contamination factors have been observed for Zn, Cr, and Ba in some localities. Results of the comparison of element contents in sediments in a 15-year period (2018 vs. 2003) indicated that the situation with toxic element content in sediments along Kupa River improved formost of its course. Unfortunately, on the lower course of the river, the situation has worsened. Using the example of Kupa River sediments, it was shown that the magnetic susceptibility method is excellent indetecting increased values of Cr.


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.


2019 ◽  
Vol 54 (2) ◽  
Author(s):  
Juan Luis Trujillo-Cárdenas ◽  
Nereida P. Saucedo-Torres ◽  
Pedro Faustino Zárate del Valle ◽  
Nely Ríos-Donato ◽  
Eduardo Mendizábal ◽  
...  

Heavy metals chemical speciation in Lake Chapala sediments was studied using sequential extraction to assess the mobility of potentially biotoxic metals and to elucidate their sources. Lake water quality was also studied. Results show Cd, Pb, Cr present in exchangeable and carbonate fractions indicating anthropogenic origin. An ecologic history indicates anthropogenic sources of Cd, Pb, Cr during 1960-2006. Risk Assessment Code indicates very high risk of pollution for water column due to high potential detachment of heavy metals.


Minerals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 111 ◽  
Author(s):  
Baolin Liu ◽  
Wensi Zhang ◽  
Guangxi Chi

Sediment core and porewater samples from the Western coastal tidal flat in Bohai Bay, China, were collected for meals and physical-chemical properties analysis. The vertical distribution characteristics of eight metals along the core was investigated based on 137Cs and 210Pb radionuclide dating. The chemical fractions of six metals (Cu, Pb, Zn, Ni, Mn and Cd) were also measured based on the modified European Community Bureau of Reference (BCR) sequential extraction procedures to better understand the mobility and bioavailability of these metals in the sediment. In addition, geoaccumulation index (Igeo) and risk assessment code (RAC) are used to assess risk status of these metals in the environment. 210Pb measurement indicates a sedimentation rate of about −1.87 cm∙year−1. The metals Cu, Zn, Pb and Ni show similar vertical distributions throughout the core, while Mn and Cd show different distribution patterns. Ni, Cu, Pb and Zn are strongly associated with the residual fraction while Mn and Cd are dominant in the acid-soluble fraction. According to the estimated diffusive fluxes, the Zn ions were the most mobilized, followed by Cu, Ni, Pb, and to a lesser extent Cd. The result of Igeo shows that Ni in sediments does not reflect any pollution, and Cu, Pb and Zn are in a level from unpolluted to modest polluted throughout the core. Mn and Cd have obvious anthropogenic sources. Based on the RAC, Cd and Mn pose a high to very high risk to the local environment, respectively, due to the significant percentage of exchangeable fraction. Clay content is significantly positively correlated with Ni, Cu, Al and Fe, and Cu, Pb, Zn and Ni might originate from the same sources or be influenced by similar geochemical processes. River runoff and atmospheric deposition are important sources for heavy metals, and since 1998, domestic sewage discharge might have had an important influence on the source of heavy metals (except for Cd and Mn).


2013 ◽  
Vol 28 (1-2) ◽  
pp. 267-272
Author(s):  
Sadhana Pradhanang

The chemical forms of copper and zinc have been determined using the fractional scheme of Tessier et al. (1979) in the bed sediments of Karra River, Hetauda, Nepal. The sequential extraction revealed that high percentage of metals was associated in the residual fraction (upstream and downstream). However, in most of the sites in the industrial belt, a significant proportion of metal was associated with the non-residual fraction (64% in Cu and 45% in Zn) which can be remobilized and released to the environment by various physical-chemical processes. This indicates influence of anthropogenic activities on the Karra River


2019 ◽  
Vol 24 (3) ◽  
pp. 139
Author(s):  
Mohammad Agung Nugraha ◽  
Mu’alimah Hudatwi ◽  
Fajar Indah Puspita Puspita Sari

Although concentrations of many heavy metals has been measured totally, they may not give a good indicator for environmentally hazard to organism. The purpose of this study is to identify sources, determine bioavailability, and assess risk based on the geochemical fractionation of heavy metals Pb, Cu and Zn on the surface sediments of Kelabat Bay, Bangka Island. Fractionation of heavy metals was analyzed by sequential extraction. The concentrations of heavy metals Pb, Cu, and Zn in sediments ranged from 8.86-29.21 mg.kg-1 (average 16.85 mg /kg), 0.16-9.54 mg.kg-1 (average 4.39 mg.kg-1), and 25.58-237.24 mg.kg-1 (average 71.99 mg.kg-1). Pb and Zn in Kelabat Bay are more bound to non-residual fractions (F1+F2+F3) or non-resistant with a range of 60.63-89.87% and 47.98-84.66% that are mainly come from anthropogenic activities. Cu tend to be stored or bound to the residual fraction (F4) with a proportion of 97.7-100% meaning that it comes from natural sources. Based on the Risk Assessment Code (RAC), Pb have a low to moderate risk in the environment and Zn heavy metals are not at risk to low. These conditions indicate the potential for biological availability (bioavailability) of Pb and Zn in the inner bay waters. For heavy metals Cu is not at risk in the environment.


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.


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.


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