scholarly journals Acinetobacter tandoii ZM06 Assists Glutamicibacter nicotianae ZM05 in Resisting Cadmium Pressure to Preserve Dipropyl Phthalate Biodegradation

2021 ◽  
Vol 9 (7) ◽  
pp. 1417
Author(s):  
Xuejun Wang ◽  
Si Shen ◽  
Hao Wu ◽  
Haixia Wang ◽  
Lvjing Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Heavy Metals ◽  
Microbial Consortia ◽  
Environmental Media ◽  
Degrading Bacterium ◽  
Coculture System ◽  
Heavy Metals Contamination ◽  
Metabolite Inhibition ◽  
Comparative Transcriptomic Analysis ◽  
Scanning Electron

Dipropyl phthalate (DPrP) coexists with cadmium as cocontaminants in environmental media. A coculture system including the DPrP-degrading bacterium Glutamicibacter nicotianae ZM05 and the nondegrading bacterium Acinetobacter tandoii ZM06 was artificially established to degrade DPrP under Cd(II) stress. Strain ZM06 relieved the pressure of cadmium on strain ZM05 and accelerated DPrP degradation in the following three ways: first, strain ZM06 adsorbed Cd(II) on the cell surface (as observed by scanning electron microscopy) to decrease the concentration of Cd(II) in the coculture system; second, the downstream metabolites of ZM05 were utilized by strain ZM06 to reduce metabolite inhibition; and third, strain ZM06 supplied amino acids and fatty acids to strain ZM05 to relieve stress during DPrP degradation, which was demonstrated by comparative transcriptomic analysis. This study provides an elementary understanding of how microbial consortia improve the degradation efficiency of organic pollutants under heavy metals contamination.

Evaluation of computer-controlled SEM in the study of metal-contaminated soils

2003 ◽  
Vol 67 (2) ◽  
pp. 219-231 ◽  
Author(s):  
H. W. Langmi ◽  
J. Watt
Keyword(s):  
Electron Microscopy ◽  
Heavy Metals ◽  
Contaminated Soils ◽  
X Ray ◽  
Computer Controlled ◽  
Weathering Crusts ◽  
Individual Particles ◽  
Element Mapping ◽  
Scanning Electron

Computer-controlled scanning electron microscopy (CCSEM) has been assessed for the determination of form and size distribution of heavy metals in urban contaminated soils. Metal distributions within individual particles were determined using X-ray element mapping. The sites selected for study were (1) around a landfill site, previously a colliery in Wolverhampton, UK and (2) a private garden adjacent to a railway in Nottingham, UK. Backscattered thresholding techniques were used to isolate the Pb-containing categories. The classification results for both Wolverhampton and Nottingham soils were generally similar but more Pb-containing classes were observed for the Nottingham samples when a comparison was made between results of the same size fractions. However, difficulties with the technique arose when particles showing chemically similar weathering crusts were assigned to the same class, despite having different internal compositions. The CCSEM data therefore need to be interpreted with caution and their application limited to situations in which particle internal complexity is not an issue.

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

Study on the adsorption of bacteria in ceramsite and their synergetic effect on adsorption of heavy metals

2013 ◽  
Vol 69 (2) ◽  
pp. 407-413 ◽  
Author(s):  
Shan Qiu ◽  
Fang Ma ◽  
Xu Huang ◽  
Shanwen Xu
Keyword(s):  
Electron Microscopy ◽  
Heavy Metals ◽  
Heavy Metal ◽  
Scanning Electron Microscopy ◽  
Adsorption Capacity ◽  
Synergetic Effect ◽  
Covalent Bond ◽  
Metal Adsorption ◽  
Heavy Metal Adsorption ◽  
Scanning Electron

In this paper, heavy metal adsorption by ceramsite with or without Bacillus subtilis (B. subtilis) immobilization was studied, and the synergetic effect of ceramsite and bacteria was discussed in detail. To investigate the roles of the micro-pore structure of ceramsite and bacteria in removing heavy metals, the amount of bacteria immobilized on the ceramsite was determined and the effect of pH was evaluated. It was found that the immobilization of B. subtilis on the ceramsite was attributed to the electrostatic attraction and covalent bond. The scanning electron microscopy results revealed that, with the presence of ceramsite, there was the conglutination of B. subtilis cells due to the cell outer membrane dissolving. In addition, the B. subtilis immobilized ceramsite showed a different adsorption capacity for different heavy metals, with the adsorption capacity ranking of La3+ > Cu2+ > Mg2+ > Na+.

An Experimental Approach for Studying Chalcopyrite Leaching and Passivation in Column Bioleaching

2009 ◽  
Vol 71-73 ◽  
pp. 381-384
Author(s):  
Tuomas van der Meer ◽  
Jussi Liipo ◽  
Jaakko Leppinen
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Chemical Analysis ◽  
Experimental Approach ◽  
Microbial Consortia ◽  
Heap Bioleaching ◽  
Different Temperatures ◽  
Leaching Solution ◽  
Continuous Potential ◽  
Scanning Electron

The effect of different microbial consortia on the leaching of chalcopyrite was studied at different temperatures and solution compositions with Boliden’s Aitik ore in column reactors simulating heap bioleaching. The columns were equipped with sampling chambers and chalcopyrite mineral electrodes in order to investigate the passivation of chalcopyrite. The sampling chambers were filled with agglomerated ore and pieces of chalcopyrite-rich ore. In addition to chemical analysis of the leaching solution and solids the progress of leaching of chalcopyrite was studied by continuous potential measurements with chalcopyrite electrodes. The occurrence and composition of potentially passivating layers on the surfaces of the electrodes and the samples taken from sample chambers were examined by optical and scanning electron microscopy.

An Eco-Friendly Procedure for Preparation of Activated Carbon as a Capture Material of Heavy Metals in Wastewater

2020 ◽  
Vol 12 (8) ◽  
pp. 1157-1163
Author(s):  
Foziah F. Al-Fawzan
Keyword(s):  
Electron Microscopy ◽  
Heavy Metals ◽  
Activated Carbon ◽  
Contact Time ◽  
Heavy Elements ◽  
Surface Scanning ◽  
Dried Fruits ◽  
Initial Concentration ◽  
Synthetic Adsorbents ◽  
Scanning Electron

This study aims to prepare an activated carbon from environmentally and inexpensive materials such as banana peels. The synthetic activated carbon has been employed in the capture of heavy elements e.g., copper (Cu), zinc (Zn) and cadmium (Cd) ions from wastewater. The spectroscopic (Fourier-transform infrared; FTIR) and morphological surface (scanning electron microscopy; SEM) investigations of the activated carbon were assigned. Adsorption of mentioned heavy metals upon the activated carbon studies were performed with different parameters such as effect of contact time, initial concentration of the heavy metal and pH (2–10) of the solution. A comparison of the adsorption capacity of the synthetic activated carbon (dried banana peels) with different adsorbents previously used (dried fruits peels) for Cu(II), Zn(II) and Cd(II) ions removal from wastewater streams shows its observable efficiency over many other treated and untreated natural and synthetic adsorbents. The Cu(II) ions showed the highest removal efficiency followed by Cd(II) then Zn(II) ions.

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.

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