INSOLUBILIZATION OF HEAVY METALS IN VOLCANIC DEPOSIT WITH MAGNESIUM OXIDE INSOLUBILIZER

2020 ◽  
Vol 76 (7) ◽  
pp. III_393-III_401
Author(s):  
Yutaka DOTE ◽  
Kenichi ITO ◽  
Tomoo SEKITO ◽  
Seiichi OBANA ◽  
Shingo FUJII
Keyword(s):  
Heavy Metals ◽  
Magnesium Oxide ◽  
Volcanic Deposit

scholarly journals Immobilization of Lead and Zinc Leached from Mining Residual Materials in Kabwe, Zambia: Possibility of Chemical Immobilization by Dolomite, Calcined Dolomite, and Magnesium Oxide

Minerals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 763 ◽  
Author(s):  
Pawit Tangviroon ◽  
Kenta Noto ◽  
Toshifumi Igarashi ◽  
Takeshi Kawashima ◽  
Mayumi Ito ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Magnesium Oxide ◽  
Batch Experiments ◽  
Chemical Immobilization ◽  
Effluent Standards ◽  
Lead And Zinc ◽  
Co Precipitation

Massive amount of highly contaminated mining residual materials (MRM) has been left unattended and has leached heavy metals, particularly lead (Pb) and zinc (Zn) to the surrounding environments. Thus, the performance of three immobilizers, raw dolomite (RD), calcined dolomite (CD), and magnesium oxide (MO), was evaluated using batch experiments to determine their ability to immobilize Pb and Zn, leached from MRM. The addition of immobilizers increased the leachate pH and decreased the amounts of dissolved Pb and Zn to different extents. The performance of immobilizers to immobilize Pb and Zn followed the following trend: MO > CD > RD. pH played an important role in immobilizing Pb and Zn. Dolomite in RD could slightly raise the pH of the MRM leachate. Therefore, the addition of RD immobilized Pb and Zn via adsorption and co-precipitation, and up to 10% of RD addition did not reduce the concentrations of Pb and Zn to be lower than the effluent standards in Zambia. In contrast, the presence of magnesia in CD and MO significantly contributed to the rise of leachate pH to the value where it was sufficient to precipitate hydroxides of Pb and Zn and decrease their leaching concentrations below the regulated values. Even though MO outperformed CD, by considering the local availability of RD to produce CD, CD could be a potential immobilizer to be implemented in Zambia.

Synthesis of a unique nanostructured magnesium oxide coated magnetite cluster composite and its application for the removal of selected heavy metals

2017 ◽  
Vol 174 ◽  
pp. 290-300 ◽  
Author(s):  
Ranjini Nagarajah ◽  
Kien Tiek Wong ◽  
Gooyong Lee ◽  
Kyoung Hoon Chu ◽  
Yeomin Yoon ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Magnesium Oxide

scholarly journals An Investigation and Comparison of Removing Heavy Metals (Lead and Chromium) from Aqueous Solutions Using Magnesium Oxide Nanoparticles

2016 ◽  
Vol 25 (2) ◽  
pp. 557-562 ◽  
Author(s):  
Abdollah Dargahi ◽  
Hafez Gholestanifar ◽  
Parviz Darvishi ◽  
Amir Karami ◽  
Syed Hadi Hasan ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Aqueous Solutions ◽  
Magnesium Oxide ◽  
Oxide Nanoparticles ◽  
Magnesium Oxide Nanoparticles

scholarly journals Obtaining high-purity bishophite based on thermohydrolysis magnesium oxide and hydrochloric acid

2019 ◽  
Vol 63 (3) ◽  
pp. 370-376
Author(s):  
L. V. Dikhtievskaya ◽  
O. N. Labkovich ◽  
V. V. Shevchuk
Keyword(s):  
Heavy Metals ◽  
Hydrochloric Acid ◽  
Magnesium Oxide ◽  
High Purity ◽  
Water Soluble ◽  
Sulfate Ions ◽  
Insoluble Form ◽  
Magnesium Salts ◽  
Washing Water

It is shown that in principle, it is possible to obtain bischofite of high purity by converting bischofite lyes purified from heavy metals, iron and sulfate ions into an insoluble form (magnesium oxide, basic magnesium salts) using their hydrohydrolysis method, washing water-soluble impurities and synthesizing bischofite from a purified thermohydrolysis product and salt acid.

Observations of the Thermal Decomposition of Brucite

1968 ◽  
Vol 26 ◽  
pp. 446-447
Author(s):  
P. L. Burnett ◽  
W. R. Mitchell ◽  
C. L. Houck
Keyword(s):  
Thermal Decomposition ◽  
Magnesium Oxide ◽  
Basal Plane ◽  
Magnesium Ions ◽  
A Value ◽  
Reaction Proceeds

Natural Brucite (Mg(OH)2) decomposes on heating to form magnesium oxide (MgO) having its cubic ﹛110﹜ and ﹛111﹜ planes respectively parallel to the prism and basal planes of the hexagonal brucite lattice. Although the crystal-lographic relation between the parent brucite crystal and the resulting mag-nesium oxide crystallites is well known, the exact mechanism by which the reaction proceeds is still a matter of controversy. Goodman described the decomposition as an initial shrinkage in the brucite basal plane allowing magnesium ions to shift their original sites to the required magnesium oxide positions followed by a collapse of the planes along the original <0001> direction of the brucite crystal. He noted that the (110) diffraction spots of brucite immediately shifted to the positions required for the (220) reflections of magnesium oxide. Gordon observed separate diffraction spots for the (110) brucite and (220) magnesium oxide planes. The positions of the (110) and (100) brucite never changed but only diminished in intensity while the (220) planes of magnesium shifted from a value larger than the listed ASTM d spacing to the predicted value as the decomposition progressed.

Time-resolved high-resolution electron microscopy of structural stability in mgo clusters

1996 ◽  
Vol 54 ◽  
pp. 672-673
Author(s):  
T. Kizuka ◽  
N. Tanaka
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Magnesium Oxide ◽  
Structural Stability ◽  
High Resolution Electron Microscopy ◽  
Video Tape ◽  
Solid State Physics ◽  
Time Resolved ◽  
Resolution Electron ◽  
Structural And Functional Properties

Structure and stability of atomic clusters have been studied by time-resolved high-resolution electron microscopy (TRHREM). Typical examples are observations of structural fluctuation in gold (Au) clusters supported on silicon oxide films, graphtized carbon films and magnesium oxide (MgO) films. All the observations have been performed on the clusters consisted of single metal element. Structural stability of ceramics clusters, such as metal-oxide, metal-nitride and metal-carbide clusters, has not been observed by TRHREM although the clusters show anomalous structural and functional properties concerning to solid state physics and materials science.In the present study, the behavior of ceramic, magnesium oxide (MgO) clusters is for the first time observed by TRHREM at 1/60 s time resolution and at atomic resolution down to 0.2 nm.MgO and gold were subsequently deposited on sodium chloride (001) substrates. The specimens, single crystalline MgO films on which Au particles were dispersed were separated in distilled water and observed by using a 200-kV high-resolution electron microscope (JEOL, JEM2010) equipped with a high sensitive TV camera and a video tape recorder system.

Sampling and analysis of the air-water interface with SEM and EDS of microlayers

1989 ◽  
Vol 47 ◽  
pp. 1004-1005
Author(s):  
Randall W. Smith ◽  
John Dash
Keyword(s):  
Heavy Metals ◽  
Surface Microlayer ◽  
Surface Films ◽  
Water Interface ◽  
Physical Processes ◽  
Infrared Spectroscopic Analysis ◽  
Eds Analysis ◽  
Air Water Interface ◽  
Significant Area ◽  
Bulk Chemical

The structure of the air-water interface forms a boundary layer that involves biological ,chemical geological and physical processes in its formation. Freshwater and sea surface microlayers form at the air-water interface and include a diverse assemblage of organic matter, detritus, microorganisms, plankton and heavy metals. The sampling of microlayers and the examination of components is presently a significant area of study because of the input of anthropogenic materials and their accumulation at the air-water interface. The neustonic organisms present in this environment may be sensitive to the toxic components of these inputs. Hardy reports that over 20 different methods have been developed for sampling of microlayers, primarily for bulk chemical analysis. We report here the examination of microlayer films for the documentation of structure and composition.Baier and Gucinski reported the use of Langmuir-Blogett films obtained on germanium prisms for infrared spectroscopic analysis (IR-ATR) of components. The sampling of microlayers has been done by collecting fi1ms on glass plates and teflon drums, We found that microlayers could be collected on 11 mm glass cover slips by pulling a Langmuir-Blogett film from a surface microlayer. Comparative collections were made on methylcel1ulose filter pads. The films could be air-dried or preserved in Lugol's Iodine Several slicks or surface films were sampled in September, 1987 in Chesapeake Bay, Maryland and in August, 1988 in Sequim Bay, Washington, For glass coverslips the films were air-dried, mounted on SEM pegs, ringed with colloidal silver, and sputter coated with Au-Pd, The Langmuir-Blogett film technique maintained the structure of the microlayer intact for examination, SEM observation and EDS analysis were then used to determine organisms and relative concentrations of heavy metals, using a Link AN 10000 EDS system with an ISI SS40 SEM unit. Typical heavy microlayer films are shown in Figure 3.

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