Effects of Leptospirillum ferriphilum and Acidithiobacillus caldus on surface properties of pyrrhotite

2009 ◽  
Vol 100 (1-2) ◽  
pp. 72-75 ◽  
Author(s):  
Guohua Gu ◽  
Kaile Zhao ◽  
Guanzhou Qiu ◽  
Yuehua Hu ◽  
Xiaojun Sun
Keyword(s):  
Surface Properties ◽  
Leptospirillum Ferriphilum ◽  
Acidithiobacillus Caldus

Adhesion of Acidithiobacillus Caldus and Leptospirillum Ferriphilum on Pyrite and their Effect on Surface Properties of Sulfide Minerals

2009 ◽  
Vol 71-73 ◽  
pp. 449-452
Author(s):  
G. Gu ◽  
Li Jun Su ◽  
Guan Zhou Qiu ◽  
Y. Hu
Keyword(s):  
Surface Properties ◽  
Isoelectric Point ◽  
Sulfide Minerals ◽  
Ferrous Ion ◽  
Bacterial Cells ◽  
Leptospirillum Ferriphilum ◽  
Acidithiobacillus Caldus ◽  
Ft Ir ◽  
Bacterial Adsorption ◽  
Strong Ability

Acidithiobacillus caldus and Leptospirillum ferriphilum cells grown in different energy substances (ferrous ion, sulfur and pyrite) were used. The adhesion of A. caldus and L. ferriphilum cells on pyrite and their effect on pyrite surface properties were studied by adsorption, zeta-potential and FT-IR methods, and the corrosion images of pyrite interaction with bacteria were examined using atomic force microscopy. Research showed that pyrite isoelectric point (IEP) after interaction with bacterial cells shifted towards cells isoelectric point, and the shift degree in case of interaction with A. caldus was observed to be much more pronounced than for interaction with L. ferriphilum, which can be due to higher affinity of A. caldus towards pyrite. The FT-IR spectra of pyrite treated with bacterial cells revealed the presence of the cell functional groups signifying cells adsorption. Although the adsorption density of A. caldus on pyrite was higher than that of L. ferriphilum, L. ferriphilum with strong ability to oxidize ferrous ion showed better leaching efficiency than A. caldus with strong ability to oxidize sulfur for pyrite leaching. The results demonstrated that more important of indirect action (L. ferriphilum) than direct action (A. caldus) on pyrite.Introduction Bacterial adsorption to minerals is an initial step in bacterial leaching for metal recovery [1]. It has been reported that bacterial adhesion is dependent not only on the biochemical properties of the organism but also on the interfacial properties of the various interfaces existing in a bioleaching system[2].The bacteria-mineral interactions result in the changes of their surface properties. The elucidation of their alternate will be beneficial for bioleaching processes. Both Acidithiobacillus caldus and Leptospirillum ferriphilum are known for their ability to inhabit acidic environments and derive energy from oxidation of inorganic substances with natural occurrence in ore deposits and acid mine drainage and high affinity towards sulfide minerals [3-5]. In this work, the alterations of surface properties of pyrite after interaction with L. ferriphilum and A. caldus are studied, and the changes in surface properties caused by bacterial adsorption are discussed with reference to bioleaching behavior of pyrite.

scholarly journals Intermediates Transformation of Bornite Bioleaching by Leptospirillum ferriphilum and Acidithiobacillus caldus

Minerals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 159 ◽  
Author(s):  
Maoxin Hong ◽  
Xingxing Wang ◽  
Lingbo Wu ◽  
Chaojun Fang ◽  
Xiaotao Huang ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Photoelectron Spectrum ◽  
Elemental Sulfur ◽  
Electrochemical Analysis ◽  
Intermediate Species ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrochemical Tests ◽  
Leptospirillum Ferriphilum ◽  
Acidithiobacillus Caldus

Bioleaching experiments, electrochemical tests, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were conducted to investigate the intermediates transformation of bornite by Leptospirillum ferriphilum and Acidithiobacillus caldus. The bioleaching experimental results showed that the presence of L. ferriphilum and A. caldus significantly accelerated the bornite bioleaching. In addition, the intermediate species of bornite bioleaching with these two kinds of bacteria were similar. Electrochemical analysis indicated that the dissolution of bornite was an acid-consuming process. The results of XRD showed that intermediate species, namely covellite (CuS), mooihoekit (Cu9Fe9S16) and isocubanite (CuFe2S3), were formed during bornite bioleaching, and a mass of elemental sulfur was formed in the late stage of bioleaching. The Cu 2p photoelectron spectrum revealed that Cu was present in the form of Cu (I) during the bornite bioleaching. Additionally, the S 2p3/2 photoelectron spectrum suggested that S2− and S22− were gradually converted to Sn2−/S0, and the formation of elemental sulfur hindered the further dissolution of the bornite.

Analysis of Microbial Community in Heap Bioleaching of Low-Grade Copper Sulfide Ores

2018 ◽  
Vol 777 ◽  
pp. 277-281
Author(s):  
He Shang ◽  
Biao Wu ◽  
Jian Kang Wen ◽  
Xing Lan Cui
Keyword(s):  
Microbial Community ◽  
Acidithiobacillus Ferrooxidans ◽  
Copper Sulfide ◽  
Heterotrophic Bacteria ◽  
Low Grade ◽  
Sequencing Technology ◽  
Leptospirillum Ferriphilum ◽  
Acidithiobacillus Caldus ◽  
Sulfobacillus Thermosulfidooxidans ◽  
Number Of Microorganisms

High-throughput sequencing technology also known as "next generation" sequencing technology, compared with the traditional sequencing method has the characteristics of fast speed, high flux, low cost. In recent years the technology in the detection of microbial diversity has been fully applied. In this study, the microbial community of ore heap in different area and different depth was studied by using this method. The results showed the bio - heap leaching of low - grade secondary copper sulfide ore in Zijinshan from China could effectively recover the copper in the ore. The number of microorganisms in the center was significantly larger than that on the edge of ore heap, and as the depth increases in the heap, the number of microorganisms decreases. The dominant bacteria in the ore heap center was Acidithiobacillus ferrooxidans, in addition there were also some Sulfobacillus thermosulfidooxidans, Ferroplasma cupricumulans, Acidithiobacillus caldus and a small amount of Leptospirillum ferriphilum in the center of the ore heap. Unlike the ore heap center, Sulfobacillus thermosulfidooxidans was the main species on the edge of the ore heap, moreover Acidithiobacillus ferrooxidans, Ferroplasma cupricumulans, Acidithiobacillus caldus and a small amount of Leptospirillum ferriphilum were found on the edge of the ore heap. In addition, some heterotrophic bacteria such as Pseudomonas, Serratia, Sediminibacterium, Stenotrophomonas, Brevundimonas and Variovorax were found both in the center and the edge of the sample, these heterotrophic bacteria may be beneficial for the leaching of valuable metals.

Investigation of Intermediates Evolutions during Bornite Bioleaching by Mesophilic Mixed Bacteria

2017 ◽  
Vol 262 ◽  
pp. 159-163
Author(s):  
Xing Xing Wang ◽  
Ming Hao Hu ◽  
Xiao Tao Huang ◽  
Rui Liao ◽  
Hong Bo Zhao ◽  
...  
Keyword(s):  
Redox Potential ◽  
Photoelectron Spectroscopy ◽  
Dissolution Process ◽  
Surface Species ◽  
X Ray Diffraction ◽  
Xps Spectra ◽  
X Ray ◽  
Leptospirillum Ferriphilum ◽  
Acidithiobacillus Caldus ◽  
Mixed Bacteria

In this study, bioleaching experiments, X-ray Diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS) were conducted to investigate the intermediates and surface species of bornite leached by mesophilic mixed bacteria of Leptospirillum. ferriphilum and Acidithiobacillus. caldus. Bioleaching experiments results showed that the mixed bacteria induced higher redox potential and significantly increased the copper extractions. In the presence of mesophilic mixed bacteria, bornite bioleaching was not inhibited by jarosite and S8. The evolution of intermediates during bornite dissolution was proposed: Cu5FeS4→ Cu9Fe9S16→CuFe2S3→CuS→Cu2+, the presence of mesophilic mixed bacteria accelerated the dissolution process. XPS spectra showed that the Cu was existed as Cu(I) species in different period, and confirmed that the presence of polysulfide and jarosite.

Investigation of Controlled Redox Potential with Pyrite during Chalcopyrite Bioleaching by Mixed Moderately Thermophiles

2017 ◽  
Vol 262 ◽  
pp. 281-284
Author(s):  
Xiao Tao Huang ◽  
Jun Wang ◽  
Hong Bo Zhao ◽  
Min Gan ◽  
Rui Liao ◽  
...  
Keyword(s):  
Redox Potential ◽  
Ferrous Ion ◽  
Copper Extraction ◽  
Ferrous Ions ◽  
Sem Images ◽  
Leptospirillum Ferriphilum ◽  
Acidithiobacillus Caldus ◽  
High Copper ◽  
Constant Ph

Various methods of controlling redox potential (ORP) with electrochemical bioreactor and others have been investigated to increase copper extraction of chalcopyrite in bioleaching,but less attention has been paid to reducing ferric to ferrous ions. Therefore, in this work, the redox potential of chalcopyrite bioleaching system in the presence of mixed moderately thermophiles containing Leptospirillum. ferriphilum,Acidithiobacillus. caldus and Sulfobacillus.thermosulfidooxidans has been controlled by pyrite. It was found that at a constant pH of 2.0, the addition of pyrite can reduce ferric to ferrous ion to a large extent, and the lower ORP values can be obtained. Bioleaching experiments indicated that the time for adding pyrite caused different bioleaching behaviors of chalcopyrite. The high copper extraction can be obtained by added pyrite at a low ORP values (<420 mV vs. Ag/AgCl). The XRD tests and SEM images showed that the amounts of formed jarosite increased as the pyrite addition, and the loose and porous jarosite can be found at low ORP values.

Biological and Surface Properties of C-Type Virus Particles Produced by Novikoff Ascites Hepatoma Cells

1977 ◽  
Vol 35 ◽  
pp. 388-389
Author(s):  
D.C. Hixson ◽  
J.C. Chan ◽  
J.M. Bowen ◽  
E.F. Walborg
Keyword(s):  
Surface Properties ◽  
Ricinus Communis ◽  
Rat Kidney ◽  
Leukemia Virus ◽  
Viral Envelope ◽  
Virus Particles ◽  
Chemically Induced ◽  
Sarcoma Virus ◽  
Hepatocarcinoma Cells ◽  
Type C

Several years ago Karasaki (1) reported the production of type C virus particles by Novikoff ascites hepatocarcinoma cells. More recently, Weinstein (2) has reported the presence of type C virus particles in cell cultures derived from transplantable and primary hepatocellular carcinomas. To date, the biological function of these virus and their significance in chemically induced hepatocarcinogenesis are unknown. The present studies were initiated to determine a possible role for type C virus particles in chemically induced hepatocarcinogenesis. This communication describes results of studies on the biological and surface properties of type C virus associated with Novikoff hepatocarcinoma cells.Ecotropic and xenotropic murine leukemia virus (MuLV) activity in ascitic fluid of Novikoff tumor-bearing rats was assayed in murine sarcoma virus transformed S+L- mouse cells and S+L- mink cells, respectively. The presence of sarcoma virus activity was assayed in non-virus-producing normal rat kidney (NRK) cells. Ferritin conjugates of concanavalin A (Fer-Con wheat germ agglutinin (Fer-WGA), and Ricinus communis agglutinins I and II (Fer-RCAI and Fer-RCAII) were used to probe the structure and topography of saccharide determinants present on the viral envelope.

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