scholarly journals Intensification of Nickel Bioleaching with Neutrophilic Bacteria Guyparkeria halophila as an Approach to Limitation of Sulfuric Acid Pollution

2021 ◽  
Vol 9 (12) ◽  
pp. 2461
Author(s):  
Tatiana Abashina ◽  
Alyona Yachkula ◽  
Elena Kaparullina ◽  
Mikhail Vainshtein
Keyword(s):  
Sulfuric Acid ◽  
Formic Acid ◽  
Mine Drainage ◽  
Low Grade ◽  
Sulfide Ores ◽  
Mining Areas ◽  
Nickel Recovery ◽  
Acidophilic Bacteria ◽  
Autotrophic Bacteria ◽  
Leaching Bacteria

Hydrometallurgical production of valuable and non-ferrous metals is traditionally accompanied with acid waste effluents/acid mine drainage leading to acidification of the mining areas. The traditional cause of this pollution is the well-known technology based on the recovery of metals with acid solutions and the application of strong acidophilic leaching bacteria for the oxidation of sulfide ores. In our experiments, we used neutrophilic autotrophic bacteria (NAB) stimulated with formic acid or coupled with acidophilic bacteria. The first approach was based on using formic acid as an energetic substrate by autotrophic bacteria. In the second case, the NAB provided initial biogenic acidification for the following growth of the inoculated acidophilic bacteria. Our experiments resulted in increased nickel recovery from the low-grade sulfide ores, which was provided by the NAB in a medium supplemented with formic acid. Bioleaching resulted in 1116 mg Ni/L (69.75%) in the medium with formate and only 35.4 mg Ni/L without formate in 43 days. As a whole, our bench scale experiments showed that the stimulated NAB can be effective at pH 7–5. Partially replacing sulfuric acid with formic acid could also give benefits via the following natural degradation of acid wastes. As a whole, this approach is more environmentally friendly than conventional bioleaching techniques.

Uranium Bioleaching from Low Grade Ore

2020 ◽  
Vol 989 ◽  
pp. 559-563
Author(s):  
Ashimkhan T. Kanayev ◽  
Khussain Valiyev ◽  
Aleksandr Bulaev
Keyword(s):  
Sulfuric Acid ◽  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Sulfuric Acid Concentration ◽  
Acid Leaching ◽  
Leach Solution ◽  
Low Grade ◽  
Bacterial Cells ◽  
Acid Mine

The goal of the present work was to perform bioleaching of uranium from low grade ore from Vostok deposit (Republic of Kazakhstan), which was previously subjected to long-term acid leaching. The ore initially contained from 0.15 to 0.20% of uranium in the form of uraninite, but ore samples used in the study contained about 0.05% of uranium, as it was exhausted during acid leaching, and uranium was partially leached. Representative samples of ore were processed in 1 m columns, leach solutions containing 5, 10, 20 g/L of sulfuric acid and bacterial cells (about 104) were percolated through the ore. Leaching was performed at ambient temperature for 70 days. In one of the percolators, the leaching was performed with leaching solution containing 10 g/L of H2SO4, cells of A. ferrooxidans, and 0.5 g/L of formaldehyde. Leaching with the solution containing 5, 10, and 20 g/L of sulfuric acid made it possible to extract 50, 53, and 58% of uranium. Addition of formaldehyde in leach solution led to the decrease in uranium extraction extent down to 37%. Thus, the results of the present work demonstrated that uranium ore exhausted during long-term acid leaching may be successfully subjected to bioleaching, that allows extracting residual quantities of uranium. Leaching rate of uranium from exhausted ore depended on both sulfuric acid concentration and microbial activity of bacteria isolated from acid mine drainage, formed on uranium deposit. In the same time, acid mine drainage may be used as a source of inoculate, to start bioleaching process.

Biomining Microorganisms' Molecular Aspects and Applications in Biotechnology and Bioremediation

2018 ◽  
pp. 1-18
Author(s):  
Jyoti Srivastava ◽  
Pradeep Srivastava
Keyword(s):  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Low Grade ◽  
Sulfide Ores ◽  
Genomics And Proteomics ◽  
Industrial Operations ◽  
Biotechnological Processes ◽  
Acidic Environments ◽  
Molecular Aspects ◽  
Extraction Of Metals

The effective dissolution of metals is widely known with the help of microorganisms called bioleaching or biomining used for the extraction of metals from their ores. Usually the microorganisms involved in biomining are chemolithoautotrophic and extremophilic in nature, since they are living in highly acidic environments (pH 1-3.0) containing heavy concentrations of metals. The commonly found genera of archea are Sulfolobus, Acidianus, Metallosphaera, and Sulfurisphaera. Throughput microbial genomics and proteomics analysis provides novel insights of metabolism mechanisms of bioleaching microbes. These microbes are having significant impact on the bioremediation of acid mine drainage (AMD) resulted from many industrial operations. Using these microbes, various metals including Ni, Cd, Cu, Fe, As, Pb, Hg, Cr, Mn, Zn, etc. are removed from the environment. Biomining microorganisms are having significant applications in the biotechnological processes including extraction of gold from ores, extraction of nickel from low-grade sulfide ores, extraction of copper from chalcopyrite, etc.

A Headspace Gas Chromatographic Method for Determination of Formic acid Content in Isosulfan Blue and in Various Drugs

2021 ◽  
Vol 37 (2) ◽  
pp. 321-329
Author(s):  
Nilesh Takale ◽  
Neelakandan Kaliyaperumal ◽  
Gopalakrishnan Mannathusamy ◽  
Rajarajan Govindasamy
Keyword(s):  
Sulfuric Acid ◽  
Formic Acid ◽  
Chromatographic Method ◽  
Isopropyl Alcohol ◽  
Class Iii ◽  
Drug Substances ◽  
Headspace Gas ◽  
Concentrated Sulfuric Acid ◽  
Gas Chromatographic Method

The Pharmaceutical industry uses formic acid in the manufacturing of various drug substances or API. At the time of manufacturing of API formic acid is use as an oxidizing agent. Formic acid is the simplest carboxylic acid. It also called methanoic acid.Formic acid present in API at high concentrations is very hazardous but in low concentrations is very beneficial. The developed and validated method was short, precise, cost effective and reproducible with FID detector and easy to use. The method is a selective and superficial analytical method for determination of formic acid in different drug substances. We report here the development and validation study of headspace gas chromatographic method to determine formic acid in different drug substances we are reported here. As per this method, the drug sample was dissolved in 0.1% (v/v) of concentrated sulfuric acid in isopropyl alcohol (IPA) in a GC headspace vial and 0.1% (v/v) of concentrated sulfuric acid in isopropyl alcohol used as a diluent. A AB-Inowax capillary column (30 m x 0.32 mm I.D. and 0.5 µm film thickness) was used under gradient conditions with FID. The formic acid peak was well separated from all other solvents that are used in synthesis of particular drug substance. The LOD and LOQof the method for formic acid are 82 ppm and 249 ppm respectively. Formic acid are low toxic class-III solvent as per ICH guideline.

scholarly journals Comparisons of formic acid oxidation at supported Pt catalyst and at low-index Pt single crystal electrodes in sulfuric acid solution

2003 ◽  
Vol 68 (11) ◽  
pp. 849-857 ◽  
Author(s):  
Amalija Tripkovic ◽  
Ksenija Popovic ◽  
Jelena Lovic
Keyword(s):  
Sulfuric Acid ◽  
Formic Acid ◽  
Single Crystal ◽  
Particle Diameter ◽  
Supported Catalyst ◽  
Pt Catalyst ◽  
Acid Oxidation ◽  
Potential Region ◽  
The Mean ◽  
Supported Pt Catalyst

The oxidation of formic acid was studied at supported Pt catalyst (47.5 wt%. Pt) and a low-index single crystal electrodes in sulfuric acid. The supported Pt catalyst was characterized by the TEM and HRTEM techniques. The mean Pt particle diameter, calculated from electrochemical measurements fits well with Pt particle size distribution determined by HRTEM. For the mean particle diameter the surface averaged distribution of low-index single crystal facets was established. Comparison of the activities obtained at Pt supported catalyst and low-index Pt single crystal electrodes revealed that Pt(111) plane is the most active in the potential region relevant for fuel cell applications.

scholarly journals Formation and characterization of acid mine drainage in the Madzharovo ore field, Southeastern Bulgaria

2021 ◽  
Vol 35 (1) ◽  
pp. 41-50
Author(s):  
Svetlana Bratkova
Keyword(s):  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Negative Impact ◽  
Sulfide Minerals ◽  
Mining Areas ◽  
Acid Mine ◽  
Zinc Cadmium ◽  
High Concentrations ◽  
Cadmium Lead ◽  
The Impact

The formation of acid mine drainage (AMD) is a serious environmental problem in areas with mining and processing industries worldwide. Their generation is associated with chemical and biological processes of oxidation of sulfide minerals, mainly pyrite. Sources of AMD can be deposits of sulfide minerals and coal with a high content of pyrite sulfur, mining waste and some tailings. The impact of AMD on surface and groundwater in mining areas continues for decades after the cessation of extraction. An example of the negative impact of generated acid mine drainage on the state of surface waters is in the region of Madzharovo. Years after the cessation of mining, the waters at the discharge points "Momina Skala", "Harman Kaya" and "Pandak Dere" are characterized by low pH values and high concentrations of iron, copper, zinc, cadmium, lead and manganese.

scholarly journals N-Formylation of Anilines with Silica Sulfuric Acid under Solvent-Free Conditions

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Davood Habibi ◽  
Payam Rahmani ◽  
Ziba Akbaripanah
Keyword(s):  
Sulfuric Acid ◽  
Formic Acid ◽  
Reaction Times ◽  
Solvent Free ◽  
Secondary Amines ◽  
Silica Sulfuric Acid ◽  
Excellent Yield ◽  
Solvent Free Conditions ◽  
Primary And Secondary Amines

N-formylation of primary and secondary amines was carried out with formic acid in the presence of silica sulfuric acid under solvent-free conditions to give the corresponding formamides in excellent yield and short reaction times.

Stable isotopes as a tool for determining transformation and fate of sulphur in AMD affected water bodies in Meghalaya

2021 ◽  
Author(s):  
Vivek Kumar ◽  
Dibyendu Paul ◽  
Sudhir Kumar
Keyword(s):  
Stable Isotopes ◽  
Coal Mining ◽  
Environmental Fate ◽  
Mine Drainage ◽  
Chemical Elements ◽  
Aquatic Systems ◽  
Water Bodies ◽  
Hydrochemical Parameters ◽  
Dominant Form ◽  
Mining Areas

<p>Meghalaya, also known as ‘abode of clouds’, is a state located in north-eastern part of India, blessed with abundance of water resources. In the last few decades, extensive coal mining in different parts of Meghalaya has caused detrimental changes in the environment, particularly the aquatic systems. Acid and metal loaded effluents (also known as acid mine drainage or AMD), resulting from the exposure of sulphide mineralization to oxidizing conditions from abandoned or active mining areas, are the principal environmental problems today. Sulphate (SO<sub>4</sub><sup>2-</sup>) is a major contaminant and attracts widespread attention as the dominant form of sulphur in coal mining affected aquatic systems. The increased presence of SO<sub>4</sub><sup>2- </sup>in ecosystems affected by mining activities has immense negative environmental and human health effects. Low pH and high heavy metal concentrations have been reported from streams flowing in and around the coal mining area in Meghalaya rendering the water quality to be very poor  and unfit for use as potable water.</p><p>Stable isotopes have emerged as a promising environmental tracer to understand different environmental functions and processes. Valuable information on the sources and processes can be obtained from the stable isotope ratios of chemical elements in environmental samples as the sources and processes influence history of the samples. Stable isotopes analysis combined with hydrochemical analysis enhances our understanding of transformation and environmental fate of different compounds in water bodies and can provide precise information about factors responsible for controlling water chemistry of different water bodies.</p><p>Stable isotopes of sulphur and oxygen combined with hydrochemical parameters were used as a tool for determining origin, transformation and fate of sulphur in AMD affected water bodies in Meghalaya.The study was conducted on two rivers affected by AMD, viz. Myntdu River and Lunar-Lukha River, flowing in the Jaintia Hills region of Meghalaya. The water samples collected are analysed for hydrochemical parameters and stable sulphur and oxygen isotopes (δ<sup>34</sup>S and δ<sup>18</sup>O in aqueous SO<sub>4</sub><sup>2-</sup>). The stable isotopes of sulphur and oxygen were also analysed in the coal samples from the nearby mining areas. The result provided an insight into the transformational processes of sulphur in these two AMD affected rivers and the environmental fate of sulphur.</p>

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