scholarly journals Removal of multi-heavy metals using biogenic manganese oxides generated by a deep-sea sedimentary bacterium – Brachybacterium sp. strain Mn32

Microbiology ◽  
2009 ◽  
Vol 155 (6) ◽  
pp. 1989-1996 ◽  
Author(s):  
Wenming Wang ◽  
Zongze Shao ◽  
Yanjun Liu ◽  
Gejiao Wang

A deep-sea manganese-oxidizing bacterium, Brachybacterium sp. strain Mn32, showed high Mn(II) resistance (MIC 55 mM) and Mn(II)-oxidizing/removing abilities. Strain Mn32 removed Mn(II) by two pathways: (1) oxidizing soluble Mn(II) to insoluble biogenic Mn oxides – birnessite (δ-MnO2 group) and manganite (γ-MnOOH); (2) the biogenic Mn oxides further adsorb more Mn(II) from the culture. The generated biogenic Mn oxides surround the cell surfaces of strain Mn32 and provide a high capacity to adsorb Zn(II) and Ni(II). Mn(II) oxidation by strain Mn32 was inhibited by both sodium azide and o-phenanthroline, suggesting the involvement of a metalloenzyme which was induced by Mn(II). X-ray diffraction analysis showed that the crystal structures of the biogenic Mn oxides were different from those of commercial pyrolusite (β-MnO2 group) and fresh chemically synthesized vernadite (δ-MnO2 group). The biogenic Mn oxides generated by strain Mn32 showed two to three times higher Zn(II) and Ni(II) adsorption abilities than commercial and fresh synthetic MnO2. The crystal structure and the biogenic MnO2 types may be important factors for the high heavy metal adsorption ability of strain Mn32. This study provides potential applications of a new marine Mn(II)-oxidizing bacterium in heavy metal bioremediation and increases our basic knowledge of microbial manganese oxidation mechanisms.

2009 ◽  
Vol 71-73 ◽  
pp. 633-636 ◽  
Author(s):  
Keiko Sasaki ◽  
T. Kaseyama ◽  
Tsuyoshi Hirajima

Unique properties of biogenic Mn oxides were applied to a fundamental study of separation and recovery of rare earth elements. Selective sorption of Ce3+ over La3+ ions was achieved at neutral pH values using biogenic Mn oxides produced by Paraconiothyrium sp. WL-2 strain. The selective coefficient for Ce3+ (αCe) was much greater with biogenic and synthetic Mn oxides than those for La3+ (αLa). Ce3+ ions were oxidized to CeO2 by Mn(III, IV) in Mn oxides under anaerobic conditions resulting in the release of Mn2+ ions, while La3+ ions were sorbed without a redox reaction. With an increase in coexisting La3+ ions, sorption of Ce3+ on both Mn oxides was significantly suppressed, especially with synthetic Mn oxides. The edges of the structure are competitive sites because of fewer numbers of vacant sites in synthetic Mn oxide layers. The preferential sorption on the edge sites of Mn oxides is in the order of La3+ > Ce3+. These phenomena can be expanded to separation and recovery of other rare earth elements from natural and anthropogenic sources.


Chemosphere ◽  
2020 ◽  
Vol 253 ◽  
pp. 126627 ◽  
Author(s):  
Wenjie Wan ◽  
Yonghui Xing ◽  
Xiuxiu Qin ◽  
Xiang Li ◽  
Song Liu ◽  
...  

2021 ◽  
Vol 9 (2) ◽  
pp. 429
Author(s):  
Rikuan Zheng ◽  
Shimei Wu ◽  
Chaomin Sun

Sulfur cycling is primarily driven by sulfate reduction mediated by sulfate-reducing bacteria (SRB) in marine sediments. The dissimilatory sulfate reduction drives the production of enormous quantities of reduced sulfide and thereby the formation of highly insoluble metal sulfides in marine sediments. Here, a novel sulfate-reducing bacterium designated Pseudodesulfovibrio cashew SRB007 was isolated and purified from the deep-sea cold seep and proposed to represent a novel species in the genus of Pseudodesulfovibrio. A detailed description of the phenotypic traits, phylogenetic status and central metabolisms of strain SRB007 allowed the reconstruction of the metabolic potential and lifestyle of a novel member of deep-sea SRB. Notably, P. cashew SRB007 showed a strong ability to resist and remove different heavy metal ions including Co2+, Ni2+, Cd2+ and Hg2+. The dissimilatory sulfate reduction was demonstrated to contribute to the prominent removal capability of P. cashew SRB007 against different heavy metals via the formation of insoluble metal sulfides.


Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 10
Author(s):  
Daria V. Mamonova ◽  
Anna A. Vasileva ◽  
Yuri V. Petrov ◽  
Denis V. Danilov ◽  
Ilya E. Kolesnikov ◽  
...  

Surfaces functionalized with metal nanoparticles (NPs) are of great interest due to their wide potential applications in sensing, biomedicine, nanophotonics, etc. However, the precisely controllable decoration with plasmonic nanoparticles requires sophisticated techniques that are often multistep and complex. Here, we present a laser-induced deposition (LID) approach allowing for single-step surface decoration with NPs of controllable composition, morphology, and spatial distribution. The formation of Ag, Pt, and mixed Ag-Pt nanoparticles on a substrate surface was successfully demonstrated as a result of the LID process from commercially available precursors. The deposited nanoparticles were characterized with SEM, TEM, EDX, X-ray diffraction, and UV-VIS absorption spectroscopy, which confirmed the formation of crystalline nanoparticles of Pt (3–5 nm) and Ag (ca. 100 nm) with plasmonic properties. The advantageous features of the LID process allow us to demonstrate the spatially selective deposition of plasmonic NPs in a laser interference pattern, and thereby, the formation of periodic arrays of Ag NPs forming diffraction grating


2013 ◽  
Vol 726-731 ◽  
pp. 4464-4467
Author(s):  
Wei Wei ◽  
Xue Jin Zhou ◽  
Yun Tao Gao

Taking plateau red soil as research object, using the ultrasonic-assisted organic acid extraction the heavy metal zinc in it, and analyze the form of zinc. Results showed that the extraction rate can reach 68%, with the increase of time, the extraction effect of zinc is obviously enhanced in this method. Ultrasonic-assisted citric acid extraction soil can increase the extraction rate of exchangeable, bound to carbonates and bound to iron and manganese oxides relatively.


2012 ◽  
Vol 736 ◽  
pp. 127-132
Author(s):  
Kuldeep Rana ◽  
Anjan Sil ◽  
Subrata Ray

Lithium alloying compounds as an anode materials have been a focused for high capacity lithium ion battery due to their highenergy capacity and safety characteristics. Here we report on the preparation of graphite-tin composite by using ball-milling in liquid media. The composite material has been characterized by scanning electron microscope, energy depressive X-ray spectroscopy, X-ray diffraction and Raman spectra. The lithium-ion cell made from graphite-tin composite presented initial discharge capacity of 1065 mAh/g and charge capacity 538 mAh/g, which becomes 528 mAh/g in the second cycle. The composite of graphite-tin with higher capacity compared to pristine graphite is a promising alternative anode material for lithium-ion battery.


2014 ◽  
Vol 16 (9) ◽  
pp. 2127-2136 ◽  
Author(s):  
Yuanzhi Tang ◽  
Samuel M. Webb ◽  
Emily R. Estes ◽  
Colleen M. Hansel

Manganese (Mn) oxides, which are generally considered biogenic in origin within natural systems, are the only oxidants of Cr(iii) under typical environmental conditions.


2008 ◽  
Vol 80 (11) ◽  
pp. 2537-2542 ◽  
Author(s):  
Zexun Tang ◽  
Deshu Gao ◽  
Ping Chen ◽  
Zhaohui Li ◽  
Qiang Wu

Ni1/3Co1/3Mn1/3(OH)2, a precursor of LiNi1/3Co1/3Mn1/3O2 in new-generation Li-ion batteries, was prepared by a hydroxide coprecipitation method. Scanning electronic microscopy (SEM) micrographs reveal that the precursor particles thus obtained, show regular shape with uniform size under optimized conditions. X-ray diffraction (XRD) indicates that well-ordered layer-structured LiNi1/3Co1/3Mn1/3O2 was prepared after calcination at high temperature. The final product exhibited a spherical morphology with uniform size distribution (10 μm in diameter). At the terminal charging voltage of 4.3 and 4.5 V (vs. Li/Li+), the testing cells of LiNi1/3Co1/3Mn1/3O2 delivered a specific capacity of 161.2 and 184.1 mAh g-1, respectively. The high capacity retention of 98.0 and 96.1 % after charging to 4.3 and 4.5 V for 50 cycles, respectively, indicates that this material displays excellent cycling stability even at high cut-off voltage.


2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Yan Ye ◽  
Da Yin ◽  
Bin Wang ◽  
Qingwen Zhang

We report the synthesis of three-dimensional Fe3O4/graphene aerogels (GAs) and their application for the removal of arsenic (As) ions from water. The morphology and properties of Fe3O4/GAs have been characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and superconducting quantum inference device. The 3D nanostructure shows that iron oxide nanoparticles are decorated on graphene with an interconnected network structure. It is found that Fe3O4/GAs own a capacity of As(V) ions adsorption up to 40.048 mg/g due to their remarkable 3D structure and existence of magnetic Fe3O4nanoparticles for separation. The adsorption isotherm matches well with the Langmuir model and kinetic analysis suggests that the adsorption process is pseudo-second-ordered. In addition to the excellent adsorption capability, Fe3O4/GAs can be easily and effectively separated from water, indicating potential applications in water treatment.


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