Characteristics and Removal Efficiency of Washing with Different Reagent for Soil Contaminated by Leads of Various Sources

2013 ◽  
Vol 671-674 ◽  
pp. 2613-2616
Author(s):  
Shu Fen Cheng ◽  
Yao Ting Tu ◽  
Chin Yuan Huang ◽  
Jia Rong Chen ◽  
Chi Ying Lai

Lead is a common pollutant found in soil. The characteristics of lead contaminated soil may vary depending on various sources of lead pollutants and different soils. In this research, samples were collected from soils contaminated by lead of different sources including discarded slag, lead smelting plant and gunnery firing range for conducting characteristic analyses. The samples were also subject to washing using seven different cleaning agents including acids such as HNO3 and HCl, cationic exchangers such as AlCl3, FeCl3, CaCl2 and MgCl2, as well chelating agent such as EDTA-4Na to study the efficiency of these agents of removing leads of various bindings in the contaminated soil. The results show that he most effective cleaning agents are HNO3, HCl, and EDTA-4Na, FeCl3 and AlCl3 for the exchangeable fraction of lead, HNO3, HCl and FeCl3 for carbonate bond fraction of lead, HNO3, HCl followed by EDTA-4Na and FeCl3 for Fe-Mn oxides bond fraction of lead; HNO3, HCl and FeCl3 for the organic bond fraction lead and HCl for the residual fraction of lead.

2014 ◽  
Vol 641-642 ◽  
pp. 1141-1145 ◽  
Author(s):  
Hong Li Huang ◽  
Lin Luo ◽  
Jia Chao Zhang ◽  
Pu Feng Qin ◽  
Man Yu ◽  
...  

Pot experiments were performed to investigate the effect of compost amendment on the mobility of zinc through analysis of Zn fractions in heavy metal contaminated soil. The results showed that the total Zn concentration decreased 8.11%, 10.15%, 16.15%, 20.05%, 7.28% and 5.02% after the amendment of 0, 20, 40, 60, 80, 100 g/kg compost to soil and Brassica juncea harvest, respectively. Zn was mostly concentrated in the residual fraction and Fe-Mn oxides fraction in soil. The percentage of Zn in water-soluble fraction, organic fraction and residual fraction had no correlation with the amount of compost amendment. The percentage of Zn in the exchangeable fraction decreased and the percentage of Zn in Fe-Mn oxides fractions increased obviously. Furthermore, the mobility factor of Zn decreased significantly from 19.20% without compost amendment to 19.09%, 18.70%, 18.15%, 16.45% and 16.12% after the amendment of 0, 20, 40, 60, 80, 100 g/kg compost to soil, the compost amendment could lowered the mobility and phytotoxicity of zinc through bound to Fe-Mn oxides.


2021 ◽  
Author(s):  
Teodoro Miano ◽  
Donato Mondelli ◽  
Lea Piscitelli ◽  
Hana Voca ◽  
Valeria D'Orazio

<p>Mitrovica area (northern Kosovo) presents contamination by PTE in agricultural soils caused by smelter emissions and their transfer and accumulation in cultivated plants. Soil A and B, sampled from two sites in Mitrovica municipality, showed a total content of Pb and Zn of 2153 and 3087 mg kg<sup>-1</sup>, and 3214 and 4619 mg kg<sup>-1</sup>. A pot experiment was performed to understand the phytoremediation potential of two non-food crops (Sorghum bicolor L. Moench and Brassica napus Westar), chosen for their economic importance and heavy metal accumulation capacities. Bioconcentration factor, translocation factor and tolerance Indexes clearly indicated a better performance of canola in tolerating Pb and Zn, especially in soil B, even if contained higher amounts of both metals. To evaluate different chemical and physical forms of Pb and Zn in the two soils, a modified BCR extraction scheme was employed to determine amounts bound to different soil components: exchangeable fraction (acid-soluble, carbonate and exchangeable bound), reducing fraction (metal bound to Fe- or Mn-oxides), oxidizable fraction (organic and sulphide bound), and residual fraction (strongest binding with crystalline structure). A comparison of the sum of Pb and Zn concentrations obtained from BCR relative to total digestion values (pseudo-total concentrations) showed recoveries close to 100%. Very small amounts of Pb were released during step 1 (exchangeable fraction) (6,86% - soil A and 2,12% - soil B). The highest concentration of Pb, 62,62% in soil A and 56,68% in soil B, decreased in the reducing fraction (step 2), probably occurring mainly as forms bound to Fe/Mn oxides. Step 3 (oxidizable-organic matter “OM” and sulphides) released amounts of 23,15% and 20,32% of total Pb in soil A and B. Residual fraction presented very different amounts of Pb (7,87% in soil A and 20,88% in soil B). Unlike Pb, no important differences were found in the distribution of Zn among the various fraction of the two soils, with the greater amounts contained in the exchangeable fraction of both soils, 31.11% in soil A and 21.92% in soil B. Very small amounts of Zn were released during step 2 (19,3% in soil A and 22,27% in soil B) whereas step 3 released the highest amounts of Zn in both soils (36,56% in A and 40,17% in B). Residual fraction presents similar amounts of total Zn, 13,03% in A e 15,64% in B, showing an opposite trend with respect to Pb. So, a major portion of total Pb was associated to the reducing fraction, while Zn was found mostly in oxidable one, indipendent on the origin of samples. Pb strongly interacts with Fe-/Mn oxides, and, in soil B, a greater amount is immobilized in the residual fraction. These results suggest lower mobility and bioavailability of Pb in soil B with respect to soil A, partially explaining the pot experiment.</p>


2016 ◽  
Vol 39 (1-2) ◽  
Author(s):  
Sadia Qayyum ◽  
Ibrar Khan ◽  
Yangguo Zhao ◽  
Farhana Maqbool ◽  
Changsheng Peng

AbstractMetal contamination of soil is due to mining, manufacturing and use of synthetic products (e.g. pesticides, paints, batteries, industrial waste and industrial or domestic sludge) which is a serious environmental problem. Hence, determining chemical forms of metals in soils is important to evaluate their mobility or bioavailability. Both artificial and contaminated soils were sequentially extracted to fractionate metals into the water soluble fraction (WSF), exchangeable fraction (EF), bound to carbonate fraction, bound to metal oxide fraction, organically bound fraction (OBF) and residual fraction (RF). In the case of contaminated soil, Pb and Cr are found to be associated with the carbonate fraction while in artificial soil, Pb bound to WSF and Cr with the Fe/Mn fraction. Chemical properties such as pH, electrical conductivity (EC) and textural classification of concerned soils were also analyzed. Percentage recovery was calculated to check the reliability of processes both in Pb and Cr, and it was found to be more in Cr (66% and 84%) in both artificial and contaminated soil than Pb (5% and 34%) in both soils. Analyses of extracts were carried out by atomic absorption spectrometry (AAS). Results were interpreted in terms of environmental mobility or bioavailability of metals.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Masahiko Katoh ◽  
Wataru Kitahara ◽  
Takeshi Sato

This study aimed to identify how the ratio of inorganic-to-organic components in animal manure compost (AMC) affected both lead immobilization and microbial activity in lead-contaminated soil. When AMC containing 50% or more inorganic fraction with high phosphorous content was applied to contaminated soil, the amounts of water-soluble lead in it were suppressed by over 88% from the values in the soil without compost. The residual fraction under sequential extraction increased with the inorganic fraction in the AMC; however, in those AMCs, the levels of microbial enzyme activity were the same or less than those in the control soil. The application of AMC containing 25% inorganic fraction could alter the lead phases to be more insoluble while improving microbial enzyme activities; however, no suppression of the level of water-soluble lead existed during the first 30 days. These results indicate that compost containing an inorganic component of 50% or more with high phosphorus content is suitable for immobilizing lead; however, in the case where low precipitation is expected for a month, AMC containing 25% inorganic component could be used to both immobilize lead and restore microbial activity.


Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6740
Author(s):  
Juan María Terrones-Saeta ◽  
Jorge Suárez-Macías ◽  
Antonio Bernardo-Sánchez ◽  
Laura Álvarez de Prado ◽  
Marta Menéndez Fernández ◽  
...  

Mining is an essential activity for obtaining materials necessary for the well-being and development of society. However, this activity produces important environmental impacts that must be controlled. More specifically, there are different soils near new or abandoned mining productions that have been contaminated with potentially toxic elements, and currently represent an important environmental problem. In this research, a contaminated soil from the mining district of Linares was studied for its use as a raw material for the conforming of ceramic materials, bricks, dedicated to construction. Firstly, the contaminated soil was chemically and physically characterized in order to evaluate its suitability. Subsequently, different families of samples were conformed with different percentages of clay and contaminated soil. Finally, the conformed ceramics were physically and mechanically characterized to examine the variation produced in the ceramic material by the incorporation of the contaminated soil. In addition, in this research, leachate tests were performed according to the TCLP method determining whether encapsulation of potentially toxic elements in the soil occurs. The results showed that all families of ceramic materials have acceptable physical properties, with a soil percentage of less than 80% being acceptable to obtain adequate mechanical properties and a maximum of 70% of contaminated soil to obtain acceptable leachate according to EPA regulations. Therefore, the maximum percentage of contaminated soil that can be incorporated into the ceramic material is 70% in order to comply with all standards. Consequently, this research not only avoids the contamination that contaminated soil can produce, but also valorizes this element as a raw material for new materials, avoiding the extraction of clay and reducing the environmental impact.


2020 ◽  
Vol 58 (5A) ◽  
pp. 10
Author(s):  
Van Minh Dang ◽  
Huu Tap Van ◽  
Thi Bich Hanh Nguyen ◽  
Dinh Vinh Nguyen ◽  
Thị Tuyet Nguyen ◽  
...  

This work investigated the effects of soil pH and the content ratio of natural zeolite on Cr contaminated soil. The immobilization experiments of the exchangeable Cr in contaminated soils were conducted using the batch method. The incubation experiments were carried out over 30 days in plastic bottles to determine five fraction of Cr existence (exchangeable fraction (F1), Fe/Mn/Oxide (F2), carbonate bound (F3), organic matters (F4) and residual (F5)) in amended soils after incubation. Results showed that the content and proportion of the exchangeable Cr decreased with an increase in soil pH from 5 to 9. At soil pH 5, the exchangeable Cr in soil reduced from 44.80±0.772 mg/kg (initial soil) to 17.72±0.300 mg/kg after 30 days of incubation with natural Zeolite 3%. Meanwhile, the exchangeable Cr of soil also decreased with increasing the content ratio of natural zeolite from 1% to 5% in soil. The ratio of 3% was suitable for incubation of the exchangeable Cr in contaminated soil with natural zeolite. The exchangeable Cr in contaminated soil decreased from 80.34% at un-amended soil treatment to 25.06% after incubation of 30 days. The forms of carbonate bound (F3) and organic matters (F4) in amended soils increased to 36.54% and 28% compared with 4.26% and 6.90% in un-amended contaminated soil. Ion exchange, precipitation and adsorption on the surface of natural zeolite  might be the potential mechanisms of immobilization of the exchangeable Cr. The results indicated that natural zeolite can be used as the effective adsorbent for immobilizing the exchangeable Cr in contaminated soils and leading to a decrease in the environmental risk from Cr toxicity.


2012 ◽  
Vol 518-523 ◽  
pp. 5040-5046 ◽  
Author(s):  
Li Di Gao ◽  
Naoki Kano ◽  
Yuichi Sato ◽  
Shuang Zhang ◽  
Hiroshi Imaizumi

Effect of EDTA and EDDS on phytoremediation of Pb- and Zn- contaminated soil by Brassica Juncea was investigated in this work. Especially, the effect of the kind and the method of adding chelating agent was investigated during the plant growth. Plants were grown in an environmental control system. The biomass of the whole plant was weighed, and the uptake of Pb and Zn in shoot and root were determined using ICP-AES. Consequently, the following matters have been obtained: (1) Both EDTA and EDDS significantly enhanced the translocation of metals (Pb and Zn) in soil from root to shoot. Furthermore, the two chelating agents resulted in a sharply biomass loss for more than 30% of the control. As a result, the total uptake amount of metals by Brassica Juncea was decreased (except the uptake of Pb with the addition of 3.0 mmol•kg-1 EDTA). (2) EDDS showed the higher inhibition for the growth of Brassica Juncea than EDTA. (3) The method for adding EDTA and EDDS at several times separately did not necessarily increase the uptake of heavy metals.


2019 ◽  
Vol 11 (2) ◽  
pp. 337 ◽  
Author(s):  
Yinzhong Ning ◽  
Xinmu Zhang ◽  
Binzhe Li ◽  
Yajing Wang ◽  
Jingheng Guo

Soil contamination by potentially toxic metals (PTMs) has become a public concern in China. However, the distribution and controlling factors of soil PTM fractions remain largely unknown, limiting our ability to assess their health risks and thus to make sound controlling polices. Here, we investigate the fraction distribution of cadmium (Cd) and copper (Cu) in Chinese soils and their relationships with soil pH, based on a national meta-analysis of 163 published literatures. Exchangeable Cd in southern China accounted for 19.50 ± 14.97% of total Cd, significantly (p < 0.01) higher than the corresponding 13.42 ± 6.95% in northern China. Potentially available fractions constituted about 60% of total Cd at the national scale. By contrast, about half of soil Cu existed in unavailable residual fraction. Phytoavailable (i.e., exchangeable) fraction accounted for only 2.71 ± 1.65% and 2.54 ± 1.58% of total Cu in northern and southern China, respectively. Percentages of exchangeable Cd and Cu were negatively correlated (p < 0.01) with soil pH, while potentially available fractions increased significantly (p < 0.05) with soil pH. Our results provide the first national assessment of Cd and Cu fraction distribution and their responses to soil pH variations, highlighting the necessity to consider their fraction distribution and soil properties when assessing the health risks of soil PTM contamination in China.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Molod Samiei ◽  
Abdolamir Bostani

In order to study the effect of Tehran municipal solid wastes compost on manganese accumulation in soil and to determine its concentration in any readily available plant forms (exchangeable and carbonates-bonded), Mn-oxides bonded fraction, organic matter bonded fraction, and residual fraction in a calcareous soil, a factorial experiment based on completely randomized block design (RCBD) was conducted in research field of Shahed university at different levels of municipal solid wastes compost (0, 15, 30, and 60 ton/ha) as first factor and application times (one- or two-year compost application) as second factor in three replications. Results showed that, by increasing compost level, total Mn concentration, DTPA-extractable concentration, and amounts existing in all five fractions were increased, so lowest and highest amounts of Mn were observed in control and 60 ton/ha compost application. Based on results from Mn fractionation using Tessier consecutive extraction method, Mn fractions in all samples were in the following order: residual > Fe-Mn oxides > carbonates-bonded > organic matter-bonded ≫ exchangeable fractions in which residual fraction (RE) at first and second year was dominant rather than other fractions by 34.28–43.04 and 34.28–49.48 percent, respectively. Mn concentration in Fe-Mn oxides-bonded fraction at both years was considerable. Mn amounts in Fe-Mn oxides- bonded, application times were decreased.


2010 ◽  
Vol 3 ◽  
pp. 69-78 ◽  
Author(s):  
Leonia Henry ◽  
Elijah Omutange

The aim of this work was to study the trace metals transfer between soil aquifers and the immediate sediments of the selected wetlands of Lake Victoria. The study covered five trace metals Pb, Cd, Cu, Zn and Mn as these are associated with vehicular traffic and with the combustion of fossil fuels which could both be significant sources of pollution within the wetlands of Lake Victoria basin. Three types of trace metal analyses from various locations of Katonga, Simiyu and Nyando catchments of Lake Victoria were performed: total concentrations, the concentrations in the non-residual fraction and the concentration in the exchangeable fraction. The soil characteristics: texture, pH and organic matter contents, were studied in relation to Cation Exchange Capacity (CEC) to assess the rate of movement of the metals between the soil and the wetland sediments. Eventually, the potential retention and leaching capacity of trace metals within the catchment soils and its possible impact on the composition of the receiving sediments of the wetlands were studied. The comparison between Nyando and Simiyu wetlands showed high variations in the soil characteristics and hence in leaching capacity of the studied metals. In general most areas in Nyando wetland required some measures to improve the CEC of the soil for higher agricultural productivity. Key Words: Trace metals; fractionation; CEC; leaching capacity; soil properties DOI: 10.3126/jowe.v3i0.2222 Journal of Wetlands Ecology, (2009) Vol. 3, pp 68-76


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