scholarly journals ANC–BNC Titrations and Geochemical Modeling for Characterizing Calcareous and Siliceous Mining Waste

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 257
Author(s):  
Clémentine Drapeau ◽  
Cécile Delolme ◽  
Clément Vézin ◽  
Denise Blanc ◽  
Thomas Baumgartl ◽  
...  
Keyword(s):  
Mine Drainage ◽  
Geochemical Modeling ◽  
Mining Waste ◽  
Main Element ◽  
Liquid Phases ◽  
Neutralizing Capacity ◽  
Mineral Assemblages ◽  
Ph Range ◽  
Neutral Conditions

Pyrite and calcite are mineral phases that play a major role in acid and neutral mine drainage processes. However, the prediction of acid mine drainage (AMD) or contaminated neutral drainage (CND) requires knowledge of the mineral composition of mining waste and the related potential for element release. This paper studies the combination of acid–base neutralizing capacity (ANC–BNC) with geochemical modeling for the characterization of mining waste and prediction of AMD and CND. The proposed approach is validated with three synthetic mineral assemblages: (1) siliceous sand with pyrite only, representing mining waste responsible for AMD, (2) siliceous sand with calcite and pyrite, representing calcareous waste responsible for CND, and (3) siliceous sand with calcite only, simulating calcareous matrices without any pyrite. The geochemical modeling approach using PHREEQC software was used to model pH evolution and main element release as a function of the added amount of acid or base over the entire pH range: 1 < pH < 13. For calcareous matrices (sand with calcite), the results are typical of a carbonated environment, the geochemistry of which is well known. For matrices containing pyrite, the results identify different pH values favoring the dissolution of pyrite: pH = 2 in a pyrite-only environment and pH = 6 where pyrite coexists with calcite. The neutral conditions can be explained by the buffering capacity of calcite, which allows iron oxyhydroxide precipitation. Major element release is then related to the dissolution and precipitation of the mineral assemblages. The geochemical modeling allows the prediction of element speciation in the solid and liquid phases. Our findings clearly prove the potential of combined ANC–BNC experiments along with geochemical modeling for the characterization of mining waste and the assessment of risk of AMD and CND.

scholarly journals Lead Mobilization and Speciation in Mining Waste: Experiments and Modeling

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 606
Author(s):  
Clémentine Drapeau ◽  
Rabei Argane ◽  
Cécile Delolme ◽  
Denise Blanc ◽  
Mostafa Benzaazoua ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mine Drainage ◽  
Geochemical Modeling ◽  
Buffering Capacity ◽  
Mining Waste ◽  
Accurate Identification ◽  
Geochemical Model ◽  
Neutralization Capacity ◽  
Mineral Phases ◽  
Solid Phases

Mining produces significant amounts of solid mineral waste. Mine waste storage facilities are often challenging to manage and may cause environmental problems. Mining waste is often linked to contaminated mine drainage, including acidic waters with more or less elevated concentrations of trace metals such as lead. This work presents a study on the mobilization of lead from waste from two typical mining sites: Zeida and Mibladen, two now-closed former Pb–Zn mines in the Moulouya region of Morocco. Our research investigates the mobilization potential of Pb from the waste of these mines. The study involved acid–base neutralization capacity tests (ANC–BNC) combined with geochemical modeling. Experimental data allowed for the quantification of the buffering capacity of the samples and the mobilization rates of lead as a function of pH. The geochemical model was fitted to experimental results with thermodynamic considerations. The geochemical model allowed for the identification of the mineral phases involved in providing the buffering capacity of carbonated mining waste (Mibladen) and the meager buffering capacity of the silicate mining waste (Zeida). These cases are representative of contaminated neutral drainage (CND) and acid mine drainage (AMD), respectively. The results highlight the consistency between the ANC–BNC experimental data and the associated modeling in terms of geochemical behavior, validating the approach and identifying the main mechanisms involved. The modeling approach identifies the dissolution of the main solid phases, which impact the pH and the speciation of lead as a function of the pH. This innovative approach, combining ANC–BNC experiments and geochemical modeling, allowed for the accurate identification of mineral phases and surface complexation phenomena, which control the release of lead and its speciation in drainage solutions, as well as within solid phases, as a function of pH.

Isolation and Characterization of Plasminogen Activator from Pig Leucocytes

1974 ◽  
Vol 31 (01) ◽  
pp. 072-085 ◽  
Author(s):  
M Kopitar ◽  
M Stegnar ◽  
B Accetto ◽  
D Lebez
Keyword(s):  
Molecular Weight ◽  
Plasminogen Activator ◽  
Gel Electrophoresis ◽  
Gel Filtration ◽  
Ph Optimum ◽  
Isolation And Characterization ◽  
Ph Range ◽  
Inhibition Studies ◽  
Final Purification

SummaryPlasminogen activator was isolated from disrupted pig leucocytes by the aid of DEAE chromatography, gel filtration on Sephadex G-100 and final purification on CM cellulose, or by preparative gel electrophoresis.Isolated plasminogen activator corresponds No. 3 band of the starting sample of leucocyte cells (that is composed from 10 gel electrophoretic bands).pH optimum was found to be in pH range 8.0–8.5 and the highest pH stability is between pH range 5.0–8.0.Inhibition studies of isolated plasminogen activator were performed with EACA, AMCHA, PAMBA and Trasylol, using Anson and Astrup method. By Astrup method 100% inhibition was found with EACA and Trasylol and 30% with AMCHA. PAMBA gave 60% inhibition already at concentration 10–3 M/ml. Molecular weight of plasminogen activator was determined by gel filtration on Sephadex G-100. The value obtained from 4 different samples was found to be 28000–30500.

GEOCHEMICAL MODELING OF HARD-ROCK MINE DRAINAGE AND MINE-IMPACTED WATERS

2019 ◽  
Author(s):  
Kate M. Campbell ◽  
◽  
Charles N. Alpers ◽  
Christy L. Grettenberger ◽  
Thomas N Wallis ◽  
...  
Keyword(s):  
Hard Rock ◽  
Mine Drainage ◽  
Geochemical Modeling

Characterization of water reservoirs affected by acid mine drainage: geochemical, mineralogical, and biological (diatoms) properties of the water

2015 ◽  
Vol 23 (7) ◽  
pp. 6002-6011 ◽  
Author(s):  
T. Valente ◽  
M. J. Rivera ◽  
S. F. P. Almeida ◽  
C. Delgado ◽  
P. Gomes ◽  
...  
Keyword(s):  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Water Reservoirs ◽  
Acid Mine

scholarly journals Assessment of Characteristics of Acid Mine Drainage Treated with Fly Ash

2021 ◽  
Vol 11 (9) ◽  
pp. 3910
Author(s):  
Saba Shirin ◽  
Aarif Jamal ◽  
Christina Emmanouil ◽  
Akhilesh Kumar Yadav
Keyword(s):  
Fly Ash ◽  
Acid Mine Drainage ◽  
Power Plants ◽  
Mine Drainage ◽  
Thermal Power ◽  
Mineralogical Characterization ◽  
Acid Mine ◽  
Before And After ◽  
Abandoned Coal Mines

Acid mine drainage (AMD) occurs naturally in abandoned coal mines, and it contains hazardous toxic elements in varying concentrations. In the present research, AMD samples collected from an abandoned mine were treated with fly ash samples from four thermal power plants in Singrauli Coalfield in the proximate area, at optimized concentrations. The AMD samples were analyzed for physicochemical parameters and metal content before and after fly ash treatment. Morphological, geochemical and mineralogical characterization of the fly ash was performed using SEM, XRF and XRD. This laboratory-scale investigation indicated that fly ash had appreciable neutralization potential, increasing AMD pH and decreasing elemental and sulfate concentrations. Therefore, fly ash may be effectively used for AMD neutralization, and its suitability for the management of coalfield AMD pits should be assessed further.

scholarly journals Incidence and characterisation of Bacillus cereus bacteriophages from Thua Nao, a Thai fermented soybean product

2021 ◽  
Vol 12 (1) ◽  
pp. 85-93
Author(s):  
Wallapat Phongtang ◽  
Ekachai Chukeatirote
Keyword(s):  
Bacillus Cereus ◽  
Food Industry ◽  
Pathogenic Bacteria ◽  
Morphological Analysis ◽  
Food Poisoning ◽  
Fermented Soybean ◽  
Foodborne Pathogenic Bacteria ◽  
Ph Range ◽  
Potential Use

Abstract Bacillus cereus is considered to be an important food poisoning agent causing diarrhea and vomiting. In this study, the occurrence of B. cereus bacteriophages in Thai fermented soybean products (Thua Nao) was studied using five B. cereus sensu lato indicator strains (four B. cereus strains and one B. thuringiensis strain). In a total of 26 Thua Nao samples, there were only two bacteriophages namely BaceFT01 and BaceCM02 exhibiting lytic activity against B. cereus. Morphological analysis revealed that these two bacteriophages belonged to the Myoviridae. Both phages were specific to B. cereus and not able to lyse other tested bacteria including B. licheniformis and B. subtilis. The two phages were able to survive in a pH range between 5 and 12. However, both phages were inactive either by treatment of 50°C for 2 h or exposure of UV for 2 h. It should be noted that both phages were chloroform-insensitive, however. This is the first report describing the presence of bacteriophages in Thua Nao products. The characterization of these two phages is expected to be useful in the food industry for an alternative strategy including the potential use of the phages as a biocontrol candidate against foodborne pathogenic bacteria.

scholarly journals Mineralogical and Geochemical Characterization of Gold Mining Tailings and Their Potential to Generate Acid Mine Drainage (Minas Gerais, Brazil)

Minerals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 39
Author(s):  
Mariana Lemos ◽  
Teresa Valente ◽  
Paula Marinho Reis ◽  
Rita Fonseca ◽  
Itamar Delbem ◽  
...  
Keyword(s):  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Minas Gerais ◽  
Acid Mine ◽  
Fine Grain ◽  
Mineralogical Characteristics ◽  
Tailing Dams ◽  
The One ◽  
And Control

For more than 30 years, sulfide gold ores were treated in metallurgic plants located in Nova Lima, Minas Gerais, Brazil, and accumulated in the Cocoruto tailings dam. Both flotation and leaching tailings from a deactivated circuit, as well as roasted and leaching tailings from an ongoing plant, were studied for their acid mine drainage potential and elements’ mobility. Detailed characterization of both tailings types indicates the presence of fine-grain size material hosting substantial amounts of sulfides that exhibit distinct geochemical and mineralogical characteristics. The samples from the ongoing plant show high grades of Fe in the form of oxides, cyanide, and sulfates. Differently, samples from the old circuit shave higher average concentrations of Al (0.88%), Ca (2.4%), Mg (0.96%), and Mn (0.17%), present as silicates and carbonates. These samples also show relics of preserved sulfides, such as pyrite and pyrrhotite. Concentrations of Zn, Cu, Au, and As are higher in the tailings of the ongoing circuit, while Cr and Hg stand out in the tailings of the deactivated circuit. Although the obtained results show that the sulfide wastes do not tend to generate acid mine drainage, leaching tests indicate the possibility of mobilization of toxic elements, namely As and Mn in the old circuit, and Sb, As, Fe, Ni, and Se in the tailings of the plant that still works. This work highlights the need for proper management and control of tailing dams even in alkaline drainage environments such as the one of the Cocoruto dam. Furthermore, strong knowledge of the tailings’ dynamics in terms of geochemistry and mineralogy would be pivotal to support long-term decisions on wastes management and disposal.

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