Molybdenite Bioleaching by Thermophilic Bacteria in a RELVA-ARBP Bioreactor

2013 ◽  
Vol 825 ◽  
pp. 418-422
Author(s):  
Rosa Elva Rivera-Santillán ◽  
Felipe Patricio-Ramírez ◽  
Francisco Artuto López-López
Keyword(s):  
Necessary Conditions ◽  
Thermophilic Bacteria ◽  
Optimal Growth ◽  
Bacterial Strains ◽  
Chemical Parameters ◽  
Thermophilic Microorganisms ◽  
Solubility In Water ◽  
Physical Chemical ◽  
Difficult Condition ◽  
Nutrients Concentration

The biological technologies application in sulfide minerals leaching to the recovery of valuables metal is a very important technological advance. They are environmental friendly and favor the sustainability of metals production in the mining and metals industry. Nowadays there is not enough basic information on molybdenite bioleaching, as well as there isn`t equip capable to obtain efficient molybdenum extractions. The difficulty depends in part on microorganisms tolerance to the molybdenum. An 85% molybdenum extraction in 6 months has been reported. This work assesses the molybdenite bioleaching from a concentrate (MoS2) with thermophilic microorganisms, at a temperature of 65 °C, on a new reactor designed at the Faculty of Chemistry of the Universidad Nacional Autónoma de México, to obtain higher extractions of molybdenum. Since bioleaching an aerobic process, the oxygen transference is a difficult condition to achieve because its solubility in water is very low and in the air 20.9 %. In addition to homogenize and maintain constant the nutrients concentration, in this new bioreactor could be established the physical, chemical and biological conditions that lead to the microorganisms optimal growth, due to these are environmental sensitive. This new equip allows us mix the nutrients in a homogeneous way. Also is able maintain constant the nutrients concentration, and all controlled physical, biological and chemical parameters. Finally does not cause any microorganisms damage. The RELVA-ARBP bioreactor allows us the control of necessary conditions for a growth more efficient of the bacterial strains. This will allow leach more rapidly the ore, increasing the molybdenum extraction kinetics. The tests results of bioleaching molybdenite with a mixed strain of extreme thermophiles carried out at 65 °C in an orbital incubator and in the RELVA-ARBP bioreactor, show a better efficiency of the bioreactor used.

Bioleaching of a Molybdenite Concentrate by Thermophilic Microorganisms in a New RELVA-RBAL 1 AIR LIFT Bio-Reactor

2015 ◽  
Vol 1130 ◽  
pp. 300-303
Author(s):  
R.E. Rivera Santillan ◽  
F. Patricio Ramirez ◽  
F.A. Lopez Lopez
Keyword(s):  
Constant Temperature ◽  
Necessary Conditions ◽  
Homogeneous Medium ◽  
Optimal Growth ◽  
Extraction Kinetics ◽  
Thermophilic Microorganisms ◽  
Molybdenite Concentrate ◽  
Physical Chemical ◽  
Air Lift

In this paper bioleaching of molybdenite concentrate (MoS2) with extreme thermophilic microorganisms at constant temperature (65°C) was studied using a new RELVA-RBAL1 bioreactor, designed at the Faculty of Chemistry of the National Autonomous University of Mexico (UNAM). The equipment keeps homogeneous medium creating physical, chemical and biological conditions that lead to optimal growth of microorganisms, improving its resistance and tolerance to molybdenum significantly, thus achieving high extraction. The RELVA-ARBAL1 AIR LIFT bioreactor allows us the control of necessary conditions for a growth more efficient of the microorganisms. This will allow leach more rapidly the ore, increasing the molybdenum extraction kinetics. The results of extraction from bioleaching molybdenite in an orbital incubator were <1% Mo. The new RELVA-RBAL 1 AIR LIFT bioreactor showed a hight efficiency, 96.84% of molybdenum extracted, most reported, in the shortest time.

Submikroninių aerozolio dalelių kilmės ir fizikinių-cheminių parametrų įtaka atmosferos šiluminei pusiausvyrai

2020 ◽  
Author(s):  
◽  
Julija Pauraitė-Dudek
Keyword(s):  
Chemical Parameters ◽  
Radiative Balance ◽  
Submicron Aerosol ◽  
Physical Chemical ◽  
The Impact ◽  
Aerosol Source

The impact of submicron aerosol source and physical-chemical parameters on atmospheric radiative balance

Dry and storm weather transport of coliforms and faecal streptococci in combined sewage

1995 ◽  
Vol 31 (7) ◽  
pp. 311-320 ◽  
Author(s):  
R. M. Ashley ◽  
W. Dabrowski
Keyword(s):  
Data Collection ◽  
Coliform Bacteria ◽  
Pathogenic Microorganisms ◽  
Chemical Parameters ◽  
Physical Chemical ◽  
Sediment Bacteria ◽  
Wet Weather ◽  
Faecal Streptococci

Combined sewage coliform bacteria are important as indicators of pathogenic microorganisms and of their possible discharge into the environment. Whilst specifying limits for viruses, most legislation recognises the difficulty of enumerating such organisms and also prescribes limits for coliforms. Despite the importance of these organisms, little is known about their numbers and behaviour in sewerage systems. A data collection programme is described which has monitored dry and wet weather sewage coliform bacteria and also sediment bacteria. These data are used to review recent UK recommendations for assessing bacteria numbers in storm discharges. It is concluded that relationships between bacteria numbers and other physical/chemical parameters may be developed during DWF, but are seasonally and catchment dependent. Extension of DWF measurements to predict storm bacteria may be possible with more data.

Management of Dairy Waste in the Sonoran Desert Using Constructed Wetland Technology

1999 ◽  
Vol 40 (3) ◽  
pp. 57-65 ◽  
Author(s):  
Martin M. Karpiscak ◽  
Robert J. Freitas ◽  
Charles P. Gerba ◽  
Luis R. Sanchez ◽  
Eylon Shamir
Keyword(s):  
Sonoran Desert ◽  
Suspended Solids ◽  
Waste Treatment ◽  
Oxygen Demand ◽  
Dairy Wastewater ◽  
Chemical Parameters ◽  
Treatment Facility ◽  
Physical Chemical ◽  
Scirpus Validus ◽  
Surface Wetland

An integrated wastewater treatment facility, consisting of upper (solids separators, anaerobic lagoons, and aerobic ponds) and lower (wetland cells) subsystems, has been built to replace the lagoon at a dairy in Arizona, USA. The collection sump of the new waste treatment facility collects all dairy wastewater outflow. Wastewater is then pumped to solids separators, and flows by gravity to anaerobic ponds and aerobic ponds. The upper subsystem is expected to treat the water sufficiently so that the wetland cells may achieve further pollutant reductions. The lower subsystem, comprised of 8 surface wetland cells with an approximate surface area of 5,000 m2, receives outflow from the ponds. The cells are planted with cattail (Typha domingensis), soft-stem bulrush (Scirpus validus), and reed (Phragmites australis). After treatment is completed via the lagoons and ponds followed by the wetland cells, the wastewater can be reused to flush barns or to irrigate crops. Performance of the overall system is evaluated by measuring physical, chemical and biological parameters in water samples taken from selected locations along the treatment system. Chemical parameters studied include biochemical oxygen demand, pH, total suspended solids, nitrogen species. Biological monitoring included coliforms (total and fecal) and Listeria monocytogenes.

scholarly journals Decomposition of Rice Chaff Using a Cocultivation System of Thermobifida fusca and Ureibacillus thermosphaericus

Proceedings ◽  
2021 ◽  
Vol 66 (1) ◽  
pp. 31
Author(s):  
Sachiko Nakamura ◽  
Norio Kurosawa
Keyword(s):  
Lignin Peroxidase ◽  
Culture Medium ◽  
Reducing Sugars ◽  
Thermophilic Bacteria ◽  
Thermobifida Fusca ◽  
Bacterial Strains ◽  
Basal Salt Medium ◽  
Moderately Thermophilic ◽  
Fuels And Chemicals ◽  
Ureibacillus Thermosphaericus

Lignocellulosic biomass comprises cellulose, hemicellulose, and lignin and is a potential source of fuels and chemicals. Although this complex biomass is persistent, it can be cooperatively decomposed by a microbial consortium in nature. In this study, a coculture of the moderately thermophilic bacteria Thermobifida fusca and Ureibacillus thermosphaericus was used for biodegradation of rice chaff. The bacterial strains were incubated in modified Brock’s basal salt medium (pH 8.0) supplemented with yeast extract and rice chaff at 50 °C for 7 days. The concentration of reducing sugars and the enzymatic activities of laccase, lignin peroxidase, cellulase, and xylanase in the supernatant of the culture medium were measured every day. The concentrations of reducing sugars in solo cultures of T. fusca and U. thermosphaericus and a mixed culture of the two strains after 7 days of incubation were 0.047, 0.040, and 0.195 mg/mL, respectively, indicating that the decomposition of rice chaff was enhanced in the coculture. Based on the results, it is thought that the lignin surrounding the cellulose was decomposed by laccase and lignin peroxidase secreted from U. thermosphaericus, resulting in cellulose and hemicellulose in the rice chaff being easily decomposed by enzymes from T. fusca.

scholarly journals Influence of Different Commercial Yeasts on Volatile Fraction of Sparkling Wines

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 247
Author(s):  
Valeriu V. Cotea ◽  
Mihai Cristian Focea ◽  
Camelia Elena Luchian ◽  
Lucia Cintia Colibaba ◽  
Elena Cristina Scutarașu ◽  
...  
Keyword(s):  
International Organization ◽  
Volatile Fraction ◽  
Chemical Parameters ◽  
Physical Chemical ◽  
Organoleptic Characteristics ◽  
Mass Spectrometry Technique ◽  
Minor Influence ◽  
Spectrometry Technique ◽  
A Minor ◽  
Aging Stage

The occurrence of aroma constituents in sparkling wines, with direct impact on their organoleptic characteristics, is affected by several factors, for example the base-wine particularities, grapes cultivar conditions, inoculated yeasts, the aging stage, and wine-making practices. This study evaluated the influence of different four commercial yeasts (IOC FIZZ™, IOC DIVINE™, LEVULIA CRISTAL™, and IOC 18-2007™) on the volatile composition of experimental sparkling wines. For this, five sparkling wines variants from the Muscat Ottonel grape variety were obtained. The base-wine was obtained through reverse osmosis and had a predetermined alcoholic concentration (10.5% vol.). In order to fulfill the proposed purpose, the experimental sparkling wines were characterized by the physical–chemical parameters (according to International Organization of Vine and Wine methods of analysis), volatile fraction (using gas-chromatography coupled with mass spectrometry technique), and sensory descriptors. Data showed a key impact on the concentration of the volatile constituents (p < 0.05), depending on the type of inoculated yeast for the second fermentation. Regarding the sensory analysis, important differences can be observed due to the type of inoculated yeast. Only a minor influence on the physical–chemical parameters was registered.

scholarly journals Determination of trace metals in water from Mangueira Lagoon – RS, Brazil

2018 ◽  
Vol 13 (3) ◽  
pp. 612-620
Author(s):  
Filipe Sousa dos Santos ◽  
Eduarda Medran Rangel ◽  
Pedro José Sanches Filho
Keyword(s):  
Trace Metals ◽  
Atomic Emission ◽  
Atomic Absorption Spectrophotometry ◽  
Emission Spectrometry ◽  
Chemical Parameters ◽  
Chelex 100 ◽  
Physical Chemical ◽  
Low Degree ◽  
Copper Zinc

Abstract Determination of trace metals was carried out in Mangueira Lagoon, in the southern zone of Rio Grande do Sul. Samples were collected at five points to evaluate the concentrations of the following trace metals: copper, zinc, lead, chromium, nickel and iron. Metals were determined by digestion with concentrated nitric acid and pre-concentrated in Chelex 100 resin analyzed by atomic absorption spectrophotometry. In parallel, the physical-chemical parameters pH, chlorides, alkalinity, hardness and organic matter in the water were determined. Potassium and sodium metals were analyzed by atomic emission spectrometry. The analyzes of pH and conductance were analyzed in the field while the others were done in the laboratory of the research group of environmental contaminants (GPCA). Through the results of physical-chemical parameters of the water, the Mangueira Lagoon exhibits a low degree of contamination, but in the future may compromise the biota of the lagoon. Regarding the focus of this work, of Cu, Cr, Fe, Ni, Pb, and Zn (heavy metals), only lead and iron obtained the values above that are established in CONAMA 357/2005.

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