scholarly journals Correlation between the Results of Sequential Extraction and Effectiveness of Immobilization Treatment of Lead- and Cadmium-Contaminated Sediment

2010 ◽  
Vol 10 ◽  
pp. 1-19 ◽  
Author(s):  
Milena B. Dalmacija ◽  
Miljana D. J. Prica ◽  
Bozo D. Dalmacija ◽  
Srdjan D. Roncevic ◽  
Ljiljana M. Rajic
Keyword(s):  
Fly Ash ◽  
Sequential Extraction ◽  
Sediment Quality ◽  
Extraction Procedure ◽  
Risk Category ◽  
The European Union ◽  
Contaminated Sediment ◽  
Worst Case ◽  
Lead And Cadmium ◽  
Dynamic Leaching

The assessment of the quality of sediment from the Great Backi Canal (Serbia), based on the pseudo-total lead (Pb) and cadmium (Cd) content according to the corresponding Dutch standards and Canadian guidelines, showed its severe contamination with these two metals. A microwave-assisted BCR (Community Bureau of Reference of the Commission of the European Union) sequential extraction procedure was employed to assess their potential mobility and risk to the aquatic environment. Comparison of the results of sequential extraction and different criteria for sediment quality assessment has led to somewhat contradictory conclusions. Namely, while the results of sequential extraction showed that Cd comes under the high-risk category, Pb shows low risk to the environment, despite its high pseudo-total content. The contaminated sediment, irrespective of the different speciation of Pb and Cd, was subjected to the same immobilization, stabilization/solidification (S/S) treatments using kaolinite, montmorillonite, kaolinite-quicklime, montmorillonite-quicklime, fly ash, zeolite, or zeolite-fly ash combination. Semi-dynamic leaching tests were conducted for Pb- and Cd-contaminated sediment in order to assess the long-term leaching behavior of these metals. In order to simulate “worst case” leaching conditions, the semi-dynamic leaching test was modified using 0.014 M acetic acid (pH = 3.25) and humic acid solutions (20 mg TOC l-1) as leachants instead of deionized water. The effectiveness of S/S treatment was evaluated by determining diffusion coefficients (De) and leachability indices (LX). The standard toxicity characteristic leaching procedure (TCLP) was applied to evaluate the extraction potential of Pb and Cd. A diffusion-based model was used to elucidate the controlling leaching mechanisms. Generally, the test results indicated that all applied S/S treatments were effective in immobilizing Pb and Cd, and the treated sediments may be considered acceptable for “controlled utilization” based on LX values, irrespective of their different availability in the untreated samples. In the majority of samples, the controlling leaching mechanism appeared to be diffusion, which indicates that a slow leaching of Cd and Pb could be expected when the above S/S agents were applied. The TCLP results showed that all S/S samples were nonhazardous.

scholarly journals New Nitrogen-Containing Recycled Fertilizers: Bioavailability of Nutrients and Harmful Elements

Recycling ◽  
2019 ◽  
Vol 4 (2) ◽  
pp. 17
Author(s):  
Janne Pesonen ◽  
Pasi Rautio
Keyword(s):  
Fly Ash ◽  
Mass Fraction ◽  
Extraction Procedure ◽  
Environmental Policies ◽  
Nitrogen Fertilizers ◽  
The European Union ◽  
Nitrogen Release ◽  
Waste Streams ◽  
Fertilizer Use ◽  
Environmental Requirements

Environmental policies of the European Union aim to increase recycling and re-use of waste-streams. One of the economically most profitable ways of re-using waste is to use it as a fertilizer. In this study, recycled nitrogen fertilizers were manufactured from industrial side-streams (sawdust, fly-ash, ammonium sulfate and lignosulfonate). A sequential extraction procedure was applied to all the products tested in this paper to make sure that the environmental requirements of a recycled fertilizer would be fulfilled. A mass fraction of up to 7.0% of nitrogen was achieved with sawdust granule and 7.2% with fly-ash-sawdust granule, indicating that the granules would be well suited to be used as nitrogen-containing fertilizers. Nitrogen release from sawdust granule was more controlled than from commercial salpetre. Sawdust combined with fly-ash can hence give a balanced nutrient mix when used together. Bioavailabilities and pseudo-total contents of harmful elements (As, Cd, Cr, Cu, Ni, Pb, and Zn) were small in all granules and cause no harm in field or forest fertilizer use.

scholarly journals Metal Speciation in Sediment from Muara Angke, Jakarta Bay Using of BCR Sequential Extraction Procedure

2019 ◽  
Vol 24 (1) ◽  
pp. 23
Author(s):  
Lestari Lestari ◽  
Fitri Budiyanto
Keyword(s):  
Heavy Metals ◽  
Sequential Extraction ◽  
Metal Speciation ◽  
Total Concentration ◽  
Extraction Procedure ◽  
Low Risk ◽  
Sequential Extraction Procedure ◽  
Residual Fraction ◽  
Risk Category ◽  
Bcr Sequential Extraction

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.

scholarly journals Solidification/stabilization of metal polluted sediment of Krivaja river

2012 ◽  
Vol 66 (4) ◽  
pp. 469-478
Author(s):  
Milena Dalmacija ◽  
Bozo Dalmacija ◽  
Dejan Krcmar ◽  
Miljana Prica ◽  
Ljiljana Rajic ◽  
...  
Keyword(s):  
Sequential Extraction ◽  
Metal Concentration ◽  
Construction Material ◽  
Sediment Quality ◽  
Extraction Procedure ◽  
Future Research ◽  
Total Metal Concentration ◽  
Copper And Zinc ◽  
Total Metal ◽  
Medium Risk

The Krivaja River is the longest natural water body (109 km) that flows completely within the borders of Serbian province of Vojvodina. In the absence of national legislation, the sediment quality was assessed in accordance with the Dutch classification methodology. It was found that the river sediment is highly contaminated with copper and zinc (192 mg kg-1 and 1218 mg kg-1 respectively), and as such is an extreme risk to the environment and human health. The solidification/stabilization (S/S) treatment with local clay, that has high capacity of cation exchange 70.2 meq/100 g and specific surface area of 630 m2 g-1, was employed for remediation of the contaminated sediment. The sequential extraction procedure showed that the copper and zinc have medium risk for the environment, with the percentage in the carbonate fraction of 18 and 22% respectively. The results of sequential extraction are not in full agreement with the results of pseudo-total metal concentration in the sediment, which only confirms that the total metal concentration is not sufficient to define the real danger to the environment. Based on the pseudo-total metals concentration, the sediment is of Class 4 (Dutch standards). However, judging from the results of sequential extraction, the metals show medium risk. Obviously, these results have to be taken into account in the assessment of the sediment quality, remediation procedures and sediment disposal in general. After the treatment, the proportion of these two metals in the first fraction is significantly reduced (Cu less than 2%, Zn 10%) in most of samples. In order to determine the long-term behavior of S/S mixtures, leaching tests were conducted in accordance with semi-dynamic ANS diffusion test for 90 days. The results indicated that clay can effectively immobilize Cu and Zn: the cumulative leached fraction of copper in mixtures with clay was in the range from 0.001% (mixture with 80% clay) to 0.15% (mixture with 10% clay), and the cumulative leached fraction of zinc in the range of 0.06% (mixture with 80% clay) to 0.10% (mixture with 10% clay). The diffusion coefficients, ranging from 1.5?10-12 cm2s-1 to 3.7?10-14 cm2s-1, showed an effective immobilization of both metals which suggests that these metals are practically immobilized in S/S mixtures even if the level of clay is low. From the point of LX values, all S/S mixtures can be used for the controlled utilization, because the leaching indices ranged from 11.8 to 13.4 for both metals. In all clay and sediment mixtures the dominant leaching mechanism is diffusion (slope values of 0.35 to 0.60), which once again confirms the effectiveness of the applied treatment and can be expected that only a very small amount of contaminants would leach into the environment over time. Future research is heading in the direction of troubleshooting the accumulation of used natural adsorbent after treatment, the possibility of permanent disposal, its regeneration or the possibility of its application as construction material.

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