scholarly journals Novel Combination of Bioleaching and Persulfate for the Removal of Heavy Metals from Metallurgical Industry Sludge

2021 ◽  
Author(s):  
Chen Chen ◽  
Huidong Li ◽  
Fengjiao Cui ◽  
Zhixia Wang ◽  
Xinxin Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Heavy Metals ◽  
Scanning Electron Microscopy ◽  
Treatment Cycle ◽  
Combined Treatment ◽  
Metallurgical Industry ◽  
Stable Form ◽  
X Ray ◽  
Removal Of Heavy Metals ◽  
Scanning Electron

Abstract The objective of this study was to remove heavy metals from the metallurgical industry sludge by bioleaching alone and bioleaching combined with persulfate (PDS). The results showed that the removal of Cu, Zn, Pb and Mn reached to 70%, 83.8%, 25.2% and 76.9% by bioleaching alone after 18 d, respectively. The experiment of bioleaching combined with PDS was carried out in which the optimal additive dosage of K2S2O8, 8 g/L, was added to bioleaching after 6 d. After 1 h, the removal of 4 heavy metals reached 75.1, 84.3, 36.7 and 81.6%, respectively. Compared with bioleaching alone, although the increase in removal efficiency was not obvious, the treatment cycle was distinctly shortened from 18 d to 6 d + 1 h. Scanning electron microscopy (SEM) results showed that the surface morphology of the sludge was changed significantly by the combined treatment. The content of heavy metals was significantly reduced after bioleaching combined with PDS by energy dispersive X-ray spectroscopy (EDX). The treated sludge mainly existed in a stable form, and the bioavailability was reduced with European Community Bureau of Reference (BCR) morphology analysis. Therefore, this study proved that the combination of bioleaching and PDS was an efficient method to remove heavy metals from metallurgical industry sludge.

scholarly journals Understanding the Mechanism of Arsenic Mobilisation and Behaviour in Tailings Dams

2017 ◽  
Vol 17 (1) ◽  
pp. 85-89
Author(s):  
B. Koomson ◽  
E. K. Asiam ◽  
W. Skinner ◽  
J. Addai-Mensah
Keyword(s):  
Electron Microscopy ◽  
Heavy Metals ◽  
Scanning Electron Microscopy ◽  
Chemical Composition ◽  
Energy Dispersive Spectroscopy ◽  
X Ray ◽  
Tailings Dams ◽  
Higher Temperature ◽  
Lower Temperature ◽  
Scanning Electron

This study was carried out on leaching of tailings at 30 ᵒC and 40 ᵒC. The mineralogical and chemical composition of the tailings material were determined by Quantitative X-Ray Diffractometry (QXRD) and Scanning Electron Microscopy combined with Energy Dispersive Spectroscopy (SEM-EDAX). The study revealed that the tailings contain sulphides (arsenopyrite and pyrite) which can leach to produce arsenic (As) and other ions in solution. The acid released during leaching depends on the temperature of leaching. More acid was produced at higher temperature (40 ᵒC) than lower temperature (30 ᵒC). It was established that arsenic precipitation from solution was higher at higher temperature (40 ᵒC) than lower temperature (30 ᵒC). Mimicking the study in a typical tailings environment, it could be proposed that As mobilisation will be enhanced at lower temperature (30 ᵒC) than at higher temperature (40 ᵒC). Keywords: Tailings, Leaching, Arsenopyrite, Heavy metals and Temperature

Application of X-ray Microanalysis for the Detection of Heavy Metals in Great Lakes Algae

1982 ◽  
Vol 39 (3) ◽  
pp. 506-509 ◽  
Author(s):  
T. Bistricki ◽  
M. Munawar
Keyword(s):  
Electron Microscopy ◽  
Heavy Metals ◽  
Heavy Metal ◽  
Scanning Electron Microscopy ◽  
Great Lakes ◽  
Generation Time ◽  
X Ray ◽  
Short Generation Time ◽  
Metal Load ◽  
Scanning Electron

A combination of scanning electron miscroscopy and energy dispersive X-ray spectroscopy (SEM-EDX) was found to be a very effective tool for characterizing the heavy metal load of Great Lakes phytoflagellates, diatoms, and green algae, and for the surveillance of heavy metal pollution. The sensitivity and short generation time of nannoplankton and the speed of the described technique makes this procedure a useful aid in contaminants research.Key words: scanning electron microscopy, X-ray microanalysis, nannoplankton, heavy metals, algae, phytoflagellates, Great Lakes, contaminants, bioaccumulation

In vivo ingestion of heavy metal particles of Se, Hg and W by murine macrophages. A study using scanning electron microscopy coupled with X-ray microanalysis

2002 ◽  
Vol 18 (8) ◽  
pp. 397-403 ◽  
Author(s):  
Duangrudee Cherdwongcharoensuk ◽  
Elisabete M Cunha ◽  
Suchart Upatham ◽  
António Sousa Pereira ◽  
Maria João R Oliveira ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Heavy Metals ◽  
Scanning Electron Microscopy ◽  
Peritoneal Macrophages ◽  
Metal Particles ◽  
Size Difference ◽  
Natural Environments ◽  
X Ray ◽  
Scanning Electron

Several heavy metals that are currently employed in industry may become polluters of work and natural environments. As particulate matter, heavy metals are suitable for entering the human body through the respiratory and digestive systems. They often end up inside phagocytes; the size of the microscopic particles modulates both their phagocytosis, and the physiology of macrophages. Here we have adopted an experimental model to investigate the ingestion of particles of three industrial heavy metals (Se, Hg, W) by murine peritoneal macrophages in vivo. The phagocytes were studied by scanning electron microscopy coupled with X-ray elemental microanalysis (SEM-XRM), a method that allows specific identification of Se, W and Hg in cells at high resolution. We found that Hg that was taken up by macrophages was organized into small, round particles (0.319 / 0.14 mm). This was in contrast with the larger size of intracellular particles of Se (2.379 / 1.84 mm) or W (1.759-1.34 mm). Ingested particles of Se and W, but not Hg, often caused bulging of the cell surface of macrophages. We conclude that particulate matters of Se, W and Hg are organized in particles of different size inside macrophages. This size difference is likely to be associated with distinct phlogistic activities of these heavy metals, Se and W causing a milder inflammatory reaction than Hg.

Identification of calcium oxalate crystals in dried or fixed tobacco leaf

1984 ◽  
Vol 42 ◽  
pp. 288-289
Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Growth And Development ◽  
Polarized Light ◽  
Calcium Oxalate Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.

Scanning Electron Microscopy and X-Ray Analyses of Dental Tissues from a Hibernator

1976 ◽  
Vol 34 ◽  
pp. 178-179
Author(s):  
M. L. Zimny ◽  
A. C. Haller
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Body Temperature ◽  
Ground Squirrel ◽  
Alveolar Bone ◽  
X Ray ◽  
Dental Tissues ◽  
Bone Minerals ◽  
Apical Tooth ◽  
Scanning Electron

During hibernation the ground squirrel is immobile, body temperature reduced and metabolism depressed. Hibernation has been shown to affect dental tissues varying degrees, although not much work has been done in this area. In limited studies, it has been shown that hibernation results in (1) mobilization of bone minerals; (2) deficient dentinogenesis and degeneration of alveolar bone; (3) presence of calculus and tears in the cementum; and (4) aggrevation of caries and pulpal and apical tooth abscesses. The purpose of this investigation was to study the effects of hibernation on dental tissues employing scanning electron microscopy (SEM) and related x-ray analyses.

Scanning Electron Microscopy and x-ray analysis of microparticles and early hydration effects

1995 ◽  
Vol 53 ◽  
pp. 692-693
Author(s):  
Yun Lu ◽  
David C. Joy
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Resolution ◽  
Morphological Development ◽  
Early Hydration ◽  
X Ray ◽  
Blended Cements ◽  
Powder Particles ◽  
Chemical Wastes ◽  
Scanning Electron

High resolution scanning electron microscopy (SEM) and energy dispersive x-ray analysis (EDXA) were performed to investigate microparticles in blended cements and their hydration products containing sodium-rich chemical wastes. The physical appearance of powder particles and the morphological development at different hydration stages were characterized by using high resolution SEM Hitachi S-900 and by SEM S-800 with a EDX spectrometer. Microparticles were dispersed on the sample holder and glued by 1% palomino solution. Hydrated bulk samples were dehydrated by acetone and mounted on the holder by silver paste. Both fracture surfaces and flat cutting sections of hydrating samples were prepared and examined. Some specimens were coated with an 3 nm thick Au-Pd or Cr layer to provide good conducting surfaces. For high resolution SEM S-900 observations the accelerating voltage of electrons was 1-2 KeV to protect the electron charging. Microchemical analyses were carried out by S800/EDS equipped with a LINK detector of take-off angle =40°.

Defects of Platelet Function Recognized by X-Ray Imaging and Scanning Electron Microscopy

1985 ◽  
Vol 43 ◽  
pp. 610-613
Author(s):  
M.G. Baldini ◽  
S. Morinaga ◽  
D. Minasian ◽  
R. Feder ◽  
D. Sayre ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Biology ◽  
Imaging Technique ◽  
Human Platelets ◽  
X Rays ◽  
X Ray ◽  
X Ray Imaging ◽  
Complex Phenomena ◽  
Scanning Electron

Contact X-ray imaging is presently developing as an important imaging technique in cell biology. Our recent studies on human platelets have demonstrated that the cytoskeleton of these cells contains photondense structures which can preferentially be imaged by soft X-ray imaging. Our present research has dealt with platelet activation, i.e., the complex phenomena which precede platelet appregation and are associated with profound changes in platelet cytoskeleton. Human platelets suspended in plasma were used. Whole cell mounts were fixed and dehydrated, then exposed to a stationary source of soft X-rays as previously described. Developed replicas and respective grids were studied by scanning electron microscopy (SEM).

Environmental scanning electron microscopy of fresh human gallstones reveals new morphologies of precipitated calcium salts

1992 ◽  
Vol 50 (2) ◽  
pp. 1322-1323
Author(s):  
Howard S. Kaufman ◽  
Keith D. Lillemoe ◽  
John T. Mastovich ◽  
Henry A. Pitt
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
X Ray Diffraction ◽  
Calcium Salts ◽  
Cholesterol Gallstones ◽  
X Ray ◽  
Ca Carbonate ◽  
Scanning Electron

Gallstones contain precipitated cholesterol, calcium salts, and proteins. Calcium (Ca) bilirubinate, palmitate, phosphate, and carbonate occurring in gallstones have variable morphologies but characteristic windowless energy dispersive x-ray (EDX) spectra. Previous studies of gallstone microstructure and composition using scanning electron microscopy (SEM) with EDX have been limited to dehydrated samples. In this state, Ca bilirubinates appear as either glassy masses, which predominate in black pigment stones, or as clusters, which are found mostly in cholesterol gallstones. The three polymorphs of Ca carbonate, calcite, vaterite, and aragonite, have been identified in gallstones by x-ray diffraction, however; the morphologies of these crystals vary in the literature. The purpose of this experiment was to study fresh gallstones by environmental SEM (ESEM) to determine if dehydration affects gallstone Ca salt morphology.Gallstones and bile were obtained fresh at cholecystectomy from 6 patients. To prevent dehydration, stones were stored in bile at 37°C. All samples were studied within 4 days of procurement.

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