Romanian bentonite and fly ash characterization and their use in heavy metal “in-situ” immobilization in polluted soils

This article presents the characterization of the Romanian bentonite and fly ash, using different techniques: FAAS, XRD, FT-IR, SEM and EDAX and their evaluation as sorbents for heavy metals immobilization in polluted soils coming from mining and metallurgical activities. The applicability of bentonite and fly ash for Pb (II) and Zn (II) immobilization was studied using aqueous solutions of these metals. The influence of the pH and contact time were studied. The results shown that the Romanian bentonite and fly ash could be used for Pb (II) and Zn (II) immobilization in polluted soils from brownfields.

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Romanian bentonite and fly ash characterization and their use in heavy metal “in-situ” immobilization in polluted soils

E3S Web of Conferences ◽

10.1051/e3sconf/201712301022 ◽

2017 ◽

Vol 18 ◽

pp. 01022

Author(s):

Săndica Liliana Gherghe ◽

Ildiko Anger ◽

Georgiana Moise ◽

Roxana Trusca

Keyword(s):

Heavy Metal ◽

Fly Ash ◽

In Situ Immobilization ◽

Polluted Soils

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Characterization of the Physical, Chemical, and Adsorption Properties of Coal-Fly-Ash–Hydroxyapatite Composites

Minerals ◽

10.3390/min11070774 ◽

2021 ◽

Vol 11 (7) ◽

pp. 774

Author(s):

Eleonora Sočo ◽

Dorota Papciak ◽

Magdalena M. Michel ◽

Dariusz Pająk ◽

Andżelika Domoń ◽

...

Keyword(s):

Fly Ash ◽

Coal Fly Ash ◽

Thermal Power ◽

Synthesis Conditions ◽

High Calcium ◽

Ft Ir ◽

Ir Analysis ◽

Wet Synthesis

(1) Hydroxyapatite (Hap), which can be obtained by several methods, is known to be a good adsorbent. Coal fly ash (CFA) is a commonly reused byproduct also used in environmental applications as an adsorbent. We sought to answer the following question: Can CFA be included in the method of Hap wet synthesis to produce a composite capable of adsorbing both heavy metals and dyes? (2) High calcium lignite CFA from the thermal power plant in Bełchatów (Poland) was used as the base to prepare CFA–Hap composites. Four types designated CFA–Hap1–4 were synthesized via the wet method of in situ precipitation. The synthesis conditions differed in terms of the calcium reactants used, pH, and temperature. We also investigated the equilibrium adsorption of Cu(II) and rhodamine B (RB) on CFA–Hap1–4. The data were fitted using the Langmuir, Freundlich, and Redlich–Peterson models and validated using R2 and χ2/DoF. Surface changes in CFA–Hap2 following Cu(II) and RB adsorption were assessed using SEM, SE, and FT-IR analysis. (3) The obtained composites contained hydroxyapatite (Ca/P 1.67) and aluminosilicates. The mode of Cu(II) and RB adsorption could be explained by the Redlich–Peterson model. The CFA–Hap2 obtained using CFA, Ca(NO3)2, and (NH4)2HPO4 at RT and pH 11 exhibited the highest maximal adsorption capacity: 73.6 mg Cu/g and 87.0 mg RB/g. (4) The clear advantage of chemisorption over physisorption was indicated by the Cu(II)–CFA–Hap system. The RB molecules present in the form of uncharged lactone were favorably adsorbed even on strongly deprotonated CFA–Hap surfaces.

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Heavy Metal Polluted Soils: Effect on Plants and Bioremediation Methods

Applied and Environmental Soil Science ◽

10.1155/2014/752708 ◽

2014 ◽

Vol 2014 ◽

pp. 1-12 ◽

Cited By ~ 291

Author(s):

G. U. Chibuike ◽

S. C. Obiora

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Growth Performance ◽

Anthropogenic Activities ◽

Polluted Soils

Soils polluted with heavy metals have become common across the globe due to increase in geologic and anthropogenic activities. Plants growing on these soils show a reduction in growth, performance, and yield. Bioremediation is an effective method of treating heavy metal polluted soils. It is a widely accepted method that is mostly carried outin situ; hence it is suitable for the establishment/reestablishment of crops on treated soils. Microorganisms and plants employ different mechanisms for the bioremediation of polluted soils. Using plants for the treatment of polluted soils is a more common approach in the bioremediation of heavy metal polluted soils. Combining both microorganisms and plants is an approach to bioremediation that ensures a more efficient clean-up of heavy metal polluted soils. However, success of this approach largely depends on the species of organisms involved in the process.

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Removal of heavy metal from soil and groundwater by in-situ electrokinetic remediation

Water Science & Technology ◽

10.2166/wst.2000.0586 ◽

2000 ◽

Vol 42 (7-8) ◽

pp. 335-343 ◽

Cited By ~ 4

Author(s):

S. Shiba ◽

S. Hino ◽

Y. Hirata ◽

T. Seno

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Electric Potential ◽

Potential Gradient ◽

Electrokinetic Remediation ◽

Contaminated Aquifer ◽

Physico Chemical ◽

Operational Variables ◽

Mass Transport Process

The operational variables of electrokinetic remediation have not been cleared yet, because this method is relatively new and is an innovative technique in the aquifer remediation. In order to investigate the operational variables of the electrokinetic remediation, a mathematical model has been constructed based on the physico chemical mass transport process of heavy metals in pore water of contaminated aquifer. The transport of the heavy metals is driven not only by the hydraulic flow due to the injection of the purge water but also by the electromigration due to the application of the electric potential gradient. The electric potential between anode and cathode is the important operational variable for the electrokinetic remediation. From the numerical simulations with use of this model it is confirmed that the remediation starts from the up stream anode and gradually the heavy metal is transported to the down stream cathode and drawn out through the purge water.

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Diffuse Reflectance FT-IR Characterization of Active Sites under Reaction Conditions: The Production of Oxygenates in the CO/H2 Reaction

Applied Spectroscopy ◽

10.1366/0003702944027345 ◽

1994 ◽

Vol 48 (10) ◽

pp. 1208-1212 ◽

Cited By ~ 7

Author(s):

J. J. Benítez ◽

I. Carrizosa ◽

J. A. Odriozola

Keyword(s):

Infrared Spectra ◽

Active Sites ◽

Diffuse Reflectance ◽

Reaction Conditions ◽

In Situ Drifts ◽

Ft Ir

The reactivity of a Lu2O3-promoted Rh/Al2O3 catalyst in the CO/H2 reaction is reported. Methane, heavier hydrocarbons, methanol, and ethanol are obtained. In situ DRIFTS has been employed to record the infrared spectra under the actual reaction conditions. The structure of the observed COads DRIFTS bands has been resolved into its components. The production of oxygenates (methanol and ethanol) has been correlated with the results of the deconvolution calculation. Specific sites for the production of methanol and ethanol in the CO/H2 reaction over a Rh,Lu2O3/Al2O3 catalyst are proposed.

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Assessing Soil and Plant Pollution by Abandoned Rural Waste Dumping Sites in Ningbo, China

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.138-139.1149 ◽

2011 ◽

Vol 138-139 ◽

pp. 1149-1155 ◽

Cited By ~ 1

Author(s):

Yi Dong Guan ◽

Ye Hong Du ◽

Zhen Dong Li ◽

An Cheng Luo

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Reference Value ◽

Dry Weight ◽

Rice Grain ◽

Contamination Assessment ◽

Plant Parts ◽

Metal Contents ◽

Plant Pollution

This paper reports the concentration of heavy metals (Cr, Cu, Zn, Cd and Pb) in the soils and rices surrounding the abandoned rural waste dumping sites in Ningbo. Igeo (geoaccumulation index) was calculated to assess the contamination degree of heavy metals in soils. The mean contents of Cr, Cu, Cd, Zn and Pb of soils were 33.3, 24.1, 1.5, 118.9 and 45.6 mg/(kg DW) (dry weight), respectively. All of them were much higher than that of the reference value (i.e. CK), but there were no coherent trend of the metal contents within 1-120m distance from the dumping site. Igeo of heavy metals reveals the order of Cd>Cu>Cr>Pb>Zn, and the contamination assessment of soils using Igeo indicate the moderate Cd pollution, while the soils were unpolluted-moderately overall by Cr, Cu, Zn as well as Pb. The heavy metal contents in root, stem & leaf and rice grains were all remarkable higher than that of the CK at 20-120 m distances, and the heavy metal contents in root were evidently much higher than other plant parts, while those in rice grain were lowest, indicating the great bioaccumulation trend of heavy metals. Although the metal contents in the rice grain were within the legislation limit, its bioaccumulation trend of heavy metals was remarkable, whose contents were 4.38-fold for Cr, 1.76-fold for Cu, 1.28-fold for Zn, 2.67-fold for Cd and 3.03-fold for Pb higher than that of reference value, respectively. Finally, we proposed a decentralized in-situ restoration approach for the dumping sites.

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In Situ Immobilization of Heavy-Metal-Contaminated Soils

Journal of Environmental Quality ◽

10.2134/jeq1990.00472425001900030050x ◽

1990 ◽

Vol 19 (3) ◽

pp. 632-632

Author(s):

William R. Roy

Keyword(s):

Heavy Metal ◽

Contaminated Soils ◽

In Situ Immobilization

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Simulated In-Situ Immobilization of Heavy Metals in Selected Soils of Karnataka

Fungal Genomics & Biology ◽

10.4172/2165-8056.1000122 ◽

2015 ◽

Vol 05 (01) ◽

Author(s):

Prasanna Meenakshi

Keyword(s):

Heavy Metals ◽

In Situ Immobilization

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Remediation of Pb and Cd Polluted Soils with Fulvic Acid

Forests ◽

10.3390/f12111608 ◽

2021 ◽

Vol 12 (11) ◽

pp. 1608

Author(s):

Aslihan Esringü ◽

Metin Turan ◽

Asli Cangönül

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Fulvic Acid ◽

Ornamental Plants ◽

Polluted Soil ◽

Green Technology ◽

Zinnia Elegans ◽

Fresh Weight ◽

Polluted Soils ◽

The World

Heavy metal pollution is among the important environmental problems in the world. Many techniques have already been used to remove the heavy metals such as lead (Pb) and cadmium (Cd). Among them, the phytoremediation method is an environmentally friendly and green technology. This study was carried out to determine the efficiency of fulvic acid (FA) application in removing Pb and Cd from polluted soil using Tagetes eracta L. and Zinnia elegans Jacq. ornamental plants. The results indicated that, FA application, number of flower per plants, and plant fresh weight of Tagetes eracta plants and Zinnia elegans plants increased 187.5%, 104.5% and 155.5%, 57.7%, respectively with application of 7000 mg L−1 FA at 100 mg kg−1 Pb pollution condition, whereas 42.85%, 16.5%, and 44.4–36.1% with application of 7000 mg L−1 FA at 30 mg kg±1 Cd pollution condition, respectively. With the FA application in the Zinnia elegans plant, the root part has accumulated 51.53% more Pb than the shoot part. For Cd, the shoot part accumulated 35.33% more Cd than the root. The effect of FA application on superoxide dismutase (SOD), peroxidase (POD) and, catalase (CAT) of the Tagetes eracta were decreased as 32.7%, 33.1%, and 35.1% for Pb, 21.2%, 25.1%, and 26,1%, for Cd, and 15.1%, 22.7%, and 37.7% for Pb, and 7.55%, 18.0%, and 18.8% for Cd were in Zinnia elegans respectively. In conclusion, Tagetes eracta and Zinnia elegans can not be recommended for remediation of Pb and Cd polluted area, but FA can be recommended for Pb and Cd stabilization in polluted soil.

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