scholarly journals Triborate Formation Constants and Polyborate Speciation under Hydrothermal Conditions by Raman Spectroscopy using a Titanium/Sapphire Flow Cell

2019 ◽  
Vol 123 (24) ◽  
pp. 5147-5159 ◽  
Author(s):  
Swaroop Sasidharanpillai ◽  
Hugues Arcis ◽  
Liliana Trevani ◽  
Peter R. Tremaine
Author(s):  
Jacy Conrad ◽  
Peter R. Tremaine

The first reported Raman spectra and ionization constants for the phosphate ion in H2O and D2O above 50 °C quantify deuterium isotope effects under hydrothermal conditions.


2019 ◽  
Vol 10 (5) ◽  
pp. 2275 ◽  
Author(s):  
Ben Hansson ◽  
Christian Harry Allen ◽  
Sami Qutob ◽  
Bradford Behr ◽  
Balazs Nyiri ◽  
...  

2016 ◽  
Vol 18 (34) ◽  
pp. 24081-24094 ◽  
Author(s):  
H. Arcis ◽  
J. P. Ferguson ◽  
G. H. Zimmerman ◽  
P. R. Tremaine

The limiting conductivity of borate and its association constants with sodium and potassium ions have been determined from T = 298 K to T = 623 K at p = 20 MPa, using a high-precision flow AC conductivity instrument.


2019 ◽  
Vol 48 (22) ◽  
pp. 7755-7765 ◽  
Author(s):  
Haylie L. Lobeck ◽  
Hrafn Traustason ◽  
Patrick A. Julien ◽  
John R. FitzPatrick ◽  
Sara Mana ◽  
...  

The behaviours of two uranyl peroxide nanoclusters in water heated to 180 °C were examined by in situ Raman spectroscopy.


MRS Advances ◽  
2020 ◽  
Vol 5 (51) ◽  
pp. 2623-2629
Author(s):  
Diwash Dhakal ◽  
Nadib Akram ◽  
Robert A. Mayanovic ◽  
Hakim Boukhalfa ◽  
Hongwu Xu

ABSTRACTThe transport and deposition of uranium under hydrothermal conditions in the Earth’s crust has been a subject of ongoing study but is yet to be completely understood. In addition, there is little known about the fate of nuclear waste, consisting of uranium from spent fuel and other radioactive materials, upon storage in repositories or in nuclear reactor facilities. Because the nuclear waste often comes in contact with aqueous fluids in storage environments, studies of uranyl complexation with chloride and other ligands in aqueous media, to high temperature and pressure conditions, are needed. The primary purpose of this study was to investigate the speciation of aqueous uranyl (VI) chloride complexes, in solutions having a 0.05 M uranyl concentration and [Cl] concentrations ranging from 0.2 M to 6 M, under hydrothermal conditions. The aqueous uranyl chloride complexes in the samples were studied using Raman spectroscopy and the hydrothermal diamond anvil cell (HDAC), at temperatures up to 500 °C and pressures up to ~ 0.5 GPa. The uranyl bond stretching band feature occurring in the ~810 to 870 cm-1 region was fitted using the Voigt peak shape to determine the speciation of the equilibrium uranyl chloride complexes present in the samples. As expected, the n integer value of the UO2Cln+2-n complex species increases with the increase in temperature and chloride concentration, generally trending toward charge neutrality at high temperatures.


1995 ◽  
Vol 73 (5) ◽  
pp. 716-724 ◽  
Author(s):  
Sheila Ball ◽  
John Milne

Elemental selenium dissolves in sulfite solution to form selenosulfate ion: Se + SO32− = SeSO32−.The formation constants for this equilibrium at temperatures from 0 to 35 °C are reported for the first time. The isomeric thioselenate anion, SSeO32−, is not, however, produced by the reaction of sulfur with selenite nor is the selenoselenate ion, Se2O32−, formed from selenium and selenite. Selenotrithionate is formed rapidly from the reaction of selenous acid with sulfite and hydrogen sulfite according to: HSeO3− + 3 HSO3− = Se(SO3)22− + SO42− + 2H2O.Two isomers of the selenotrithionate ion are observed by Se-77 NMR and Raman spectroscopy, one with O-bonded Se, Se(OSO2)22−, and the other with S-bonded Se, Se(SO3)22−. Both isomers are formed in reactions with hydrogen sulfite but only the O-bonded isomer is formed in sulfite solutions at ambient temperatures. The Raman and Se-77 NMR spectra of the various sulphur–selenium anions formed are given and the parallel with the reactions of selenous acid and thiols is discussed. Keywords: selenium, sulfite, selenosulfate, selenotrithionate, Se-77 NMR, Raman spectroscopy, equilibria, aqueous solutions.


Sensors ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 1839 ◽  
Author(s):  
Ann-Kathrin Kniggendorf ◽  
Christoph Wetzel ◽  
Bernhard Roth

Microplastic particles have been found in drinking water sources worldwide and, thus, also in our food and beverages. Especially small microplastics, with sizes of 1 mm and less, cannot be identified reliably without spectroscopic means such as Fourier transform infrared spectroscopy (FTIR) or Raman spectroscopy, usually applied to the particles extracted from the samples. However, for drinking and tap water, with its comparatively low biological loads, direct observation may be possible and allows a point-of-entry monitoring for beverages and food to ensure uncontaminated drinking water is being used. In a proof of concept, we apply Raman spectroscopy to observe individual microplastic particles in tap water with added particulate and fluorescent contaminants streaming with 1 L/h through a custom-made flow cell. We evaluated several tubing materials for compatibility with microplastic suspensions containing three different polymers widely found in microplastic surveys worldwide. The experiment promises the monitoring of streaming tap water and even clear surface waters for microplastics smaller than 0.1 mm.


Sign in / Sign up

Export Citation Format

Share Document