scholarly journals Layered metal sulfides: Exceptionally selective agents for radioactive strontium removal

2008 ◽  
Vol 105 (10) ◽  
pp. 3696-3699 ◽  
Author(s):  
M. J. Manos ◽  
N. Ding ◽  
M. G. Kanatzidis
Keyword(s):  
Metal Sulfides ◽  
Strontium Removal ◽  
Selective Agents

Scanning Electron Microscope Study of Bacteria on Mineral Surfaces

1976 ◽  
Vol 34 ◽  
pp. 130-131
Author(s):  
V.K. Berry
Keyword(s):  
Oxidation Reaction ◽  
Electron Microscope Study ◽  
Elemental Sulfur ◽  
Thiobacillus Ferrooxidans ◽  
Physical Contact ◽  
Metal Sulfides ◽  
Low Grade ◽  
Mineral Surfaces ◽  
Mineral Surface ◽  
Scanning Electron Microscope Study

There are two strains of bacteria viz. Thiobacillus thiooxidansand Thiobacillus ferrooxidanswidely mentioned to play an important role in the leaching process of low-grade ores. Another strain used in this study is a thermophile and is designated Caldariella .These microorganisms are acidophilic chemosynthetic aerobic autotrophs and are capable of oxidizing many metal sulfides and elemental sulfur to sulfates and Fe2+ to Fe3+. The necessity of physical contact or attachment by bacteria to mineral surfaces during oxidation reaction has not been fairly established so far. Temple and Koehler reported that during oxidation of marcasite T. thiooxidanswere found concentrated on mineral surface. Schaeffer, et al. demonstrated that physical contact or attachment is essential for oxidation of sulfur.

Identification of acid-insoluble filter-plugging compounds and optimal acid-washing procedures for tubular backpulse pressure filters

TAPPI Journal ◽  
2011 ◽  
Vol 10 (1) ◽  
pp. 17-23
Author(s):  
KEVIN TAYLOR ◽  
RICH ADDERLY ◽  
GAVIN BAXTER
Keyword(s):  
Calcium Sulfate ◽  
Membrane Filter ◽  
Sulfamic Acid ◽  
Xrd Analysis ◽  
Metal Sulfides ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gypsum Formation ◽  
Acid Washing ◽  
Hydrolysis Of

Over time, performance of tubular backpulse pressure filters in kraft mills deteriorates, even with regular acid washing. Unscheduled filter replacement due to filter plugging results in significant costs and may result in mill downtime. We identified acid-insoluble filter-plugging materials by scanning electron microscope/energy-dispersion X-ray spectroscopy (SEM/EDS) and X-ray diffraction (XRD) analysis in both polypropylene and Gore-Tex™ membrane filter socks. The major filter-plugging components were calcium sulfate (gypsum), calcium phosphate (hydroxylapatite), aluminosilicate clays, metal sulfides, and carbon. We carried out detailed sample analysis of both the standard acid-washing procedure and a modified procedure. Filter plugging by gypsum and metal sulfides appeared to occur because of the acid-washing procedure. Gypsum formation on the filter resulted from significant hydrolysis of sulfamic acid solution at temperatures greater than 130°F. Modification of the acid-washing procedure greatly reduced the amount of gypsum and addition of a surfactant to the acid reduced wash time and mobilized some of the carbon from the filter. With surfactant, acid washing was 95% complete after 40 min.

Metal Sulfides/Graphene Nanocomposites: An Overview of Preparation and Applications

2014 ◽  
Vol 6 (3) ◽  
pp. 152-160 ◽  
Author(s):  
Xiaoshuang Zheng ◽  
Jingdong Liu ◽  
Long Chen ◽  
Jianping Gao ◽  
Yousheng Tao
Keyword(s):  
Metal Sulfides ◽  
Graphene Nanocomposites

The Effect of γ-Al2O3, TiO2 and ZrO2 Supports on Hydrodesulfurization Activity of Transition-Metal Sulfides

2008 ◽  
Vol 73 (8-9) ◽  
pp. 945-955 ◽  
Author(s):  
Luděk Kaluža ◽  
Miroslav Zdražil
Keyword(s):  
Transition Metal ◽  
Aqueous Solutions ◽  
Model Reaction ◽  
Metal Sulfides ◽  
Vacuum Impregnation ◽  
Transition Metal Sulfides ◽  
Highly Active ◽  
System A ◽  
Benzothiophene Hydrodesulfurization ◽  
Hydrodesulfurization Activity

The transition metals V, Cr, Mn, Fe, Co, Ni, Mo, Ru, Rh, Pd, W, Re, Os, Ir and Pt were deposited from aqueous solutions of their salts onto conventional γ-Al2O3 and unconventional TiO2 and ZrO2 supports by vacuum impregnation and characterized in their sulfided form by a model reaction of benzothiophene hydrodesulfurization. It was found that the TiO2 and ZrO2 supports influenced predominantly positively the resulting activity of relatively low-active metals (V, Cr, Mn, Fe, Co, Ni, Mo, Ru, W and Os), whereas the highly active metals (Rh, Pd, Ir, Pt and Re) were influenced slightly negatively or not at all by those supports compared with the γ-Al2O3-supported system. A significant effect of the supports on the hydrodesulfurization-activity ranking of the transition-metal sulfides studied was ascertained.

ChemInform Abstract: Concave Reagents. Part 20. Sterically Shielded m-Terphenyls as Selective Agents in General Protonations.

ChemInform ◽  
2010 ◽  
Vol 28 (10) ◽  
pp. no-no
Author(s):  
U. LUENING ◽  
H. BAUMGARTNER ◽  
C. MANTHEY ◽  
B. MEYNHARDT
Keyword(s):  
Selective Agents ◽  
Concave Reagents

scholarly journals Influence of Selective Agents (EMJH-STAFF), Sample Filtration and pH on Leptospira Interrogans Serovar Icterohaemorrhagiae Cultivation and Isolation from Swine Urine

2021 ◽  
Vol 8 (6) ◽  
pp. 90
Author(s):  
Romana Steinparzer ◽  
Tamara Mair ◽  
Christine Unterweger ◽  
Adi Steinrigl ◽  
Friedrich Schmoll
Keyword(s):  
Diagnostic Tests ◽  
Urine Samples ◽  
Epidemiological Surveillance ◽  
Leptospira Interrogans ◽  
Sample Storage ◽  
Clinical Specimens ◽  
Negative Results ◽  
Swine Urine ◽  
Selective Agents ◽  
Phosphate Buffered Saline

Leptospira spp. cause the zoonotic disease leptospirosis, which occurs in numerous mammalians worldwide. Isolation is still important for serotyping and genotyping of Leptospira, which in turn is essential for epidemiological surveillance of leptospirosis and the development of diagnostic tests and vaccines. However, isolation of Leptospira from clinical specimens is inherently insensitive. This study was conducted to examine the influence of selective agents, sample filtration, sample pH and the use of phosphate buffered saline (PBS) buffer for sample storage to improve the success of cultivation and isolation of Leptospira interrogans serovar Icterohaemorrhagiae from swine urine. EMJH (Ellinghausen McCullough, Johnson and Harris) medium including the selective agents sulfamethoxazole, trimethoprim, amphotericin, fosfomycin and 5-fluorouracil (STAFF) increased the success of Leptospira isolation from spiked swine urine samples. Sample filtration yielded only negative results. Isolation in EMJH-STAFF was successful from swine urine with a density as low as 104 Leptospira/mL, and urine with pH ≤ 7 impaired the cultivation rate. Cultivation and isolation were not improved by the addition of PBS to spiked urine samples prior to storage for 24 h at 4 °C. The results of the study demonstrate that cultivation and isolation of leptospires from swine urine can be improved by enhanced methods.

Hydrogenation of 2,5-dimethyl-4-phenyl(p-alkylbenzyl) pyridines over metal sulfides

1972 ◽  
Vol 8 (1) ◽  
pp. 82-84
Author(s):  
M. A. Ryashentseva ◽  
Kh. M. Minachev ◽  
V. V. Dorogov ◽  
N. S. Prostakov
Keyword(s):  
Metal Sulfides
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