Predominance Diagrams of Dissolved Uranium Species and logfO2(g)-pH Diagrams of U-PO43--Nacl-H2O System at 25°C, PCO2=10-3.5 Mpa

2013 ◽  
Vol 781-784 ◽  
pp. 3-8
Author(s):  
Xin Yu Wang ◽  
Shi Jun Ni ◽  
Ze Ming Shi
Keyword(s):  
Thermodynamic Model ◽  
Uranium Concentration ◽  
Phosphate Concentration ◽  
Oxidative Condition ◽  
Nacl Concentration ◽  
Solid Phases ◽  
Ph Range ◽  
Uranium Species ◽  
Predominance Diagrams

To explore the effect of logfO2(g), pH, uranium concentration, phosphate concentration and NaCl concentration on the predominance diagrams of dissolved uranium species and formation of solid phases containing uranium in the U-PO43--NaCl-H2O system at 25 °CandPCO2=10-3.5MPa, the thermodynamic model of this system was constructed. Based on the results of calculation, the logfO2(g)-pH diagrams were drawn. It can be found that: 1) the formation of uraninite needed enough reductive condition (about logfO2(g) < -50 ), while the formation of Na-Autunite needed the strict pH range (5<pH<8) in oxidative condition. 2)The addition of phosphate concentration could promote the formation of Na-Autunite, and inhibit the formation of U4O9(C). 3)The independent increasing of uranium concentration can lead to more kinds of uranium species.4) The variance of NaCl concentration had little impact on the formation of solid phases containing uranium.

scholarly journals Isolation and Assessment of the Symbiotic Efficiency of Faba bean (Vicia faba L.) Nodulating Rhizobial Isolates from Eastern Hararghe Highlands of Ethiopia

2021 ◽  
Vol 9 (2) ◽  
pp. 91-105
Author(s):  
Mulugeta Mekonnen ◽  
Ameha Kebede
Keyword(s):  
Vicia Faba ◽  
Faba Bean ◽  
Dry Weight ◽  
Symbiotic Efficiency ◽  
Shoot Dry Weight ◽  
Nacl Concentration ◽  
Vicia Faba L ◽  
Positive Correlations ◽  
Ph Range ◽  
Rhizobial Isolates

This particular work was devoted to isolate and assess the symbiotic efficiency of faba bean (Vicia faba L.)-nodulating rhizobia isolate at few faba bean growing areas of the eastern Hararghe highlands of Ethiopia. Overall 50 rhizobia isolates were obtained from soil samples of three Woredas (districts) of the eastern Hararghe highlands using the host trap method. Out of these 50 isolates, 40 were presumptively identified as rhizobia. Among these 40 rhizobia isolates, only 31 were successful to nodulate faba bean, and authenticated as true faba bean nodulating rhizobia. Concerning the symbiotic efficiency, about 52%, 35%, and 13% of the rhizobial isolates were found to be highly effective, effective, and lowly-effective, respectively. The correlation data on the sand experiment displayed that nodule dry weight was associated positively and significantly (r = 0.494, p<0.05) with shoot dry weight while shoot dry weight was associated positively and significantly (r=0.41, p<0.05) with plant total nitrogen. Positive correlations were also observed concerning shoot dry weight and dry weight of nodules (r = 0.7, p<0.05) on unsterilized soil. Among the observed rhizobium isolates, EHHFR (4A, 6A) showed the highest symbiotic efficiency above 110%, tolerated NaCl concentration ranging from 2% to 6% and 2% to 8%, respectively, and a pH range of 4.5 to 8 and 5 to 8, respectively. Thus, based on their symbiotic efficiency at the greenhouse level and relative tolerance to extreme conditions these faba bean nodulating rhizobia isolates were recommended to be used as nominees for the future development of faba bean rhizobial inoculants after being tested on field conditions.

Natranaerobaculum magadiense gen. nov., sp. nov., an anaerobic, alkalithermophilic bacterium from soda lake sediment

2013 ◽  
Vol 63 (Pt_12) ◽  
pp. 4456-4461 ◽  
Author(s):  
Daria G. Zavarzina ◽  
Tatyana N. Zhilina ◽  
Boris B. Kuznetsov ◽  
Tatyana V. Kolganova ◽  
Georgy A. Osipov ◽  
...  
Keyword(s):  
Yeast Extract ◽  
Sequence Similarity ◽  
Soda Lake ◽  
Rrna Gene ◽  
Donor Strain ◽  
Content Type ◽  
Link Type ◽  
Nacl Concentration ◽  
Novel Genus And Species ◽  
Ph Range

An obligately alkaliphilic, anaerobic, thermo- and halotolerant, spore-forming bacterium was isolated from sediments of soda lake Magadi (Kenya) and designated strain Z-1001T. Cells of strain Z-1001T were straight, Gram-positive rods, slowly motile. Strain Z-1001T was found to be an obligate anaerobe. It grew within a pH range from 7.5 to 10.7 with an optimum at 9.25–9.5 (at 40 °C), a temperature range from 20 to 57 °C with an optimum at 45–50 °C, and a NaCl concentration range from 0 to 1.55 M with an optimum at 1.2–1.4 M. Peptides, such as meat and yeast extracts, peptone and tryptone, were fermented by Z-1001T. Carbohydrates did not support growth. With yeast extract as an electron donor, strain Z-1001T reduced S 2 O 3 2 − , NO 3 − , AsO 4 3 − , Fe(III) citrate and anthraquinone-2,6-disulfonate (AQDS) as electron acceptors. The isolate was able to grow oligotrophically with a very small amount of yeast extract: 0.03 g l−1. The main fatty acids were C16 : 0, C16 : 1ω7c , C18 : 0 and C18 : 1ω9. The DNA G+C content of the isolate was 35.6 mol%. 16S rRNA gene sequence analysis showed that strain Z-1001T is a member of family Natranaerobiaceae , clustering with the type strain of Natranaerobius thermophilus (95.8–96.0 % sequence similarity). On the basis of physiological and phylogenetic data it is proposed that strain Z-1001T ( = DSM 24923T = VKM B-2666T) represents a novel genus and species, Natranaerobaculum magadiense gen. nov., sp. nov.

Factors affecting germination of horseweed (Conyza canadensis)

Weed Science ◽  
2006 ◽  
Vol 54 (5) ◽  
pp. 898-902 ◽  
Author(s):  
Vijay K. Nandula ◽  
Thomas W. Eubank ◽  
Daniel H. Poston ◽  
Clifford H. Koger ◽  
Krishna N. Reddy
Keyword(s):  
Seedling Emergence ◽  
Soil Surface ◽  
Conyza Canadensis ◽  
Light Conditions ◽  
Complete Darkness ◽  
Continuous Darkness ◽  
Factors Affecting ◽  
Nacl Concentration ◽  
Alkaline Conditions ◽  
Ph Range

The influence of environmental factors on germination and emergence of horseweed was examined in growth chamber experiments. Germination was highest (61%) under 24/20 C day/night temperature under light. Horseweed seed germination was observed under both light (13 h photoperiod) and complete darkness (24 h), but germination under continuous darkness was only 0 to 15% compared with 0 to 61% under light. All other experiments were conducted under 24/20 C and 13-h light conditions. Germination was 19 to 36% over a pH range from 4 to 10, with a trend toward higher germination under neutral-to-alkaline conditions. Horseweed germination was > 20% at < 40 mM NaCl concentration and lowest (4%) at 160 mM NaCl. These data suggest that even at high soil salinity conditions, horseweed can germinate. Germination of horseweed decreased from 25% to 2% as osmotic potential increased from 0 (distilled water) to −0.8 MPa, indicating that germination can still occur under moderate water stress conditions. Horseweed seedling emergence was at its maximum on the soil surface, and no seedlings emerged from seeds placed at a depth of 0.5 cm or higher.

Coprecipitation Experiments Using Simulated Spent Fuel Solutions in the Presence of Metallic Iron in Synthetic Bentonitic-Granitic Water Under Oxidising Conditions

2004 ◽  
Vol 824 ◽  
Author(s):  
Javier Quiñones ◽  
Ángel González de la Huebra ◽  
Aurora Martínez Esparza
Keyword(s):  
Metallic Iron ◽  
Room Temperature ◽  
Uranium Concentration ◽  
Solid Phase ◽  
Spent Fuel ◽  
Secondary Phases ◽  
Bulk Solid ◽  
Show Evidence ◽  
Ph Range ◽  
Iron Material

AbstractThis paper presents the results obtained from coprecipitation experiments of uranyl solutions in the presence of metallic iron and/or its alteration phases in synthetic bentonitic-granitic composition water. Experiments were done under oxidising conditions at room temperature. The pH range covered was 7.4 – 8.8. Changes in the uranium concentrations and the characterisation of the secondary phases formed in the experiments were done using XRD and SEM-EDS and are presented herein.Final uranium concentration values were in the range of 2·10−5 – 5·10−4 mol (kg of H2O)−1. In all cases, results from these experiments did not show evidence of a clear effect due to the presence of iron (metallic or previously corroded) on the uranium concentration. These data were similar to those obtained by coprecipitation in similar conditions but in absence of iron material. Boltwoodite was observed [K2(UO2)2(SiO3)2(OH)2·3H2O] in iron surface materials and characterized in all experiments. Based on the experimental data obtained (uranium concentration in solution and bulk solid phase characterisation) we propose the following surface-mediated reaction:2 K+ + 2 H4SiO4 + 2 UO2+2 + 3 H2O ⇔ K2(UO2)2(SiO3)2(OH)2·3H2O + 6 H+

scholarly journals Thermococcus thioreducens sp. nov., a novel hyperthermophilic, obligately sulfur-reducing archaeon from a deep-sea hydrothermal vent

2007 ◽  
Vol 57 (7) ◽  
pp. 1612-1618 ◽  
Author(s):  
Elena V. Pikuta ◽  
Damien Marsic ◽  
Takashi Itoh ◽  
Asim K. Bej ◽  
Jane Tang ◽  
...  
Keyword(s):  
Hydrothermal Vent ◽  
Rrna Gene ◽  
Strictly Anaerobic ◽  
Black Smoker ◽  
Separate Species ◽  
Gene Sequence Analysis ◽  
Nacl Concentration ◽  
Mid Atlantic Ridge ◽  
Casamino Acids ◽  
Ph Range

A hyperthermophilic, sulfur-reducing, organo-heterotrophic archaeon, strain OGL-20PT, was isolated from ‘black smoker’ chimney material from the Rainbow hydrothermal vent site on the Mid-Atlantic Ridge (36.2°N, 33.9°W). The cells of strain OGL-20PT have an irregular coccoid shape and are motile with a single flagellum. Growth was observed within a pH range of 5.0−8.5 (optimum pH 7.0), an NaCl concentration range of 1–5 % (w/v) (optimum 3 %) and a temperature range of 55–94 °C (optimum 83–85 °C). The novel isolate is strictly anaerobic and obligately dependent upon elemental sulfur as an electron acceptor, but it does not reduce sulfate, sulfite, thiosulfate, Fe(III) or nitrate. Proteolysis products (peptone, bacto-tryptone, Casamino acids and yeast extract) are utilized as substrates during sulfur reduction. Strain OGL-20PT is resistant to ampicillin, chloramphenicol, kanamycin and gentamicin, but sensitive to tetracycline and rifampicin. The G+C content of the DNA is 52.9 mol%. The 16S rRNA gene sequence analysis revealed that strain OGL-20PT is closely related to Thermococcus coalescens and related species, but no significant homology by DNA–DNA hybridization was observed between those species and the new isolate. On the basis of physiological and molecular properties of the new isolate, we conclude that strain OGL-20PT represents a new separate species within the genus Thermococcus, for which we propose the name Thermococcus thioreducens sp. nov. The type strain is OGL-20PT (=JCM 12859T=DSM 14981T=ATCC BAA-394T).

Thermodynamic Modeling of Phase Equilibria in the FeO-MgO-Al2O3 System

2020 ◽  
Vol 989 ◽  
pp. 3-9 ◽  
Author(s):  
O.V. Samoilova ◽  
L.A. Makrovets
Keyword(s):  
Experimental Data ◽  
Phase Equilibria ◽  
Phase Diagrams ◽  
Thermodynamic Modeling ◽  
Thermodynamic Stability ◽  
Thermodynamic Model ◽  
Liquidus Surface ◽  
Melt Temperature ◽  
Oxide Melt ◽  
Solid Phases

Thermodynamic modeling of coordinates of phase diagrams’ liquidus lines of the FeO–MgO, FeO–Al2O3, MgO–Al2O3 systems and coordinates of phase diagram’s liquidus surface of the FeO–MgO–Al2O3 system has been carried out. In the course of work, a thermodynamic model which describes activity of oxide melt had been selected for each of the systems; energy parameters of the model have been determined. Regions of thermodynamic stability of solid phases which are at equilibrium with the oxide melt have been determined. Results of the modeling have been compared with experimental data existing in the literature. Modeling technique has also allowed evaluating enthalpies and entropies of FeAl2O4 and MgAl2O4 compounds’ formation out of components of the oxide melt. The obtained results are of interest for steelmaking industry processes when determining the melt temperature of a slag containing oxides of iron, magnesium and aluminum.

La2O3-modified MCM-41 for efficient phosphate removal synthesized using natural diatomite as precursor

2019 ◽  
Vol 79 (10) ◽  
pp. 1878-1886 ◽  
Author(s):  
Xiaoning Jia ◽  
Xiaojuan He ◽  
Kaixuan Han ◽  
Yuhong Ba ◽  
Xia Zhao ◽  
...  
Keyword(s):  
Phosphate Concentration ◽  
Phosphate Removal ◽  
Treated Wastewater ◽  
Molar Ratio ◽  
Phosphate Adsorption ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Isothermal Model ◽  
Enhanced Adsorption ◽  
Ph Range

Abstract In this study, an ordered mesoporous silica modified with lanthanum oxide was synthesized using diatomite as silica source and applied for adsorption of phosphate from aqueous solution. By taking cost-effectiveness for practical application into consideration, the adsorbent with a theoretical La/SiO2 molar ratio of 0.2 (La0.2M41) possessed a promising performance. In the batch adsorption tests, the adsorbents with La2O3 loading possessed markedly enhanced adsorption capacities. Phosphate uptake by La0.2M41 was pH-dependent with the highest sorption capacities observed over a pH range of 3.0–6.0. Coexistent anions displayed an adverse effect on phosphate adsorption following the order of CO32−  &gt; F−  &gt; NO3− &gt; Cl− &gt; SO42−. In the kinetic study, phosphate adsorption onto La0.2M41 followed the pseudo-second-order equation better than the pseudo-first-order, suggesting chemisorption. The Langmuir isothermal model well described the adsorption isotherm data, showing a maximum adsorption capacity for phosphate of up to 263.16 mg/g at 298 K. In a real treated wastewater effluent with phosphate concentration of 2.5 mg P/L, La0.2M41 efficiently reduced the phosphate concentration to 28 µg P/L.

Ternary cycle treatment of high saline wastewater from pesticide production using a salt-tolerant microorganism

2013 ◽  
Vol 67 (9) ◽  
pp. 1960-1966 ◽  
Author(s):  
Xiang Wu ◽  
Ya-guang Du ◽  
Yi Qu ◽  
Dong-yun Du
Keyword(s):  
Gene Sequencing ◽  
Oxygen Demand ◽  
Ethyl Chloride ◽  
Aerobic Treatment ◽  
Salt Tolerant ◽  
Chemical Oxygen Demand Removal ◽  
Saline Wastewater ◽  
Nacl Concentration ◽  
Ph Range ◽  
Immobilized Microorganism

The material of this study is provided by biological aerobic treatment of high saline wastewater from pesticide production. The microorganism used for biodegradation has been identified by gene-sequencing as a strain of Bacillus sp. SCUN. The best growth condition for the salt-tolerant microorganism has been studied by varying the pH, immobilized microorganism dosage and temperature conditions. The feasibility of pretreating wastewater in ethyl chloride production containing 4% NaCl has been discussed. It was found that under the pH range of 6.0–8.0, immobilized microorganism dosage of 1.5 g/L, temperature of 30 °C, and NaCl concentration of 0–3%, the microorganism achieves the best growth for biodegradation. After domestication, the strain can grow under 4% NaCl. This salt-tolerant microorganism is effective in the pretreated high saline wastewater. With a newly developed ternary cycle treatment, the chemical oxygen demand removal approaches 58.3%. The theoretical basis and a new method for biological treatments in biodegradation of high saline wastewater in ethyl chloride production are discussed.

Thermal Injury and Recovery of Salmonella enterica Serovar Enteritidis in Ground Chicken with Temperature, pH, and Sodium Chloride as Controlling Factors†

2006 ◽  
Vol 69 (9) ◽  
pp. 2058-2065 ◽  
Author(s):  
L. SHERRE CHAMBLISS ◽  
NEELAM NARANG ◽  
VIJAY K. JUNEJA ◽  
MARK A. HARRISON
Keyword(s):  
Salmonella Enterica ◽  
Salmonella Enteritidis ◽  
Thermal Injury ◽  
Heating Temperature ◽  
Inhibitory Effect ◽  
Salmonella Enterica Serovar Enteritidis ◽  
Randomized Design ◽  
Nacl Concentration ◽  
Ph Range ◽  
D Values

Cells of Salmonella enterica serovar Enteritidis were grown at 25 and 35°C, heat injured (55, 60, and 62.5°C), and recovered in tryptic soy broth (TSB) at various NaCl concentrations (2.0 and 3.5%) and pH levels (5.5 and 6.5). To assess the interactions of growth temperature, heating temperature, NaCl concentration and pH on the thermal injury and recovery of Salmonella Enteritidis in ground chicken, a randomized design with each experimental combination was used. When a logistic equation for nonlinear survival curves was used, D-values of cells of Salmonella Enteritidis grown at 25°C were 7.60, 5.73, and 4.81 min at 55, 60, and 62.5°C, respectively. For cells grown at 35°C, the D-values were 12.38, 7.45, and 5.70 min at 55, 60, and 62.5°C. The influence of tryptic soy agar and double modified lysine agar (DMLIA) on the recovery of heat-injured cells was determined. Recovery was significantly reduced on DMLIA at increased pH levels and NaCl concentrations. Higher numbers of cells were recovered in TSB with 2.0% NaCl than in TSB with 3.5% NaCl. It was observed that the rate of recovery of heat-injured cells was similar at each pH. Therefore, a pH range of 5.5 to 6.5 does not have a major inhibitory effect on the recovery of Salmonella Enteritidis.

Georgenia sediminis sp. nov., a moderately thermophilic actinobacterium isolated from sediment

2013 ◽  
Vol 63 (Pt_11) ◽  
pp. 4243-4247 ◽  
Author(s):  
Zhi-Qing You ◽  
Jie Li ◽  
Sheng Qin ◽  
Xin-Peng Tian ◽  
Fa-Zuo Wang ◽  
...  
Keyword(s):  
Type Species ◽  
Minor Component ◽  
Optimal Growth ◽  
Rrna Gene ◽  
Content Type ◽  
Moderately Thermophilic ◽  
Link Type ◽  
Nacl Concentration ◽  
Ph Range ◽  
A Minor

A Gram-stain-positive actinobacterium, designated strain SCSIO 15020T, was isolated from sediment of the South China Sea, and characterized by using a polyphasic approach. The temperature range for growth was 24–60 °C, with optimal growth occurring at 50 °C. The pH range for growth was 6–10 (optimum pH 8–9). The NaCl concentration range for growth was 0–5 % (w/v). The peptidoglycan type was A4α. Polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside and an unknown polar lipid. The major menaquinone was MK-8(H4); MK-7(H4) was present as a minor component. The major fatty acids (>5 %) were anteiso-C15 : 0, iso-C15 : 0 and iso-C16 : 0. The DNA G+C content of strain SCSIO 15020T was 73.2 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain SCSIO 15020T belonged to the genus Georgenia , with the closest neighbours being Georgenia muralis 1A-CT (96.3 % similarity), Georgenia thermotolerans TT02-04T (95.7 %) and Georgenia ruanii YIM 004T (95.6 %). Based on evidence from the present polyphasic study, strain SCSIO 15020T is considered to represent a novel species of the genus Georgenia , for which the name Georgenia sediminis sp. nov. is proposed. The type strain is SCSIO 15020T ( = DSM 25884T = NBRC 108941T).

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