chloride system
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Author(s):  
Tareq W. M. Amen ◽  
Meng Sun ◽  
Mitsuharu Terashima ◽  
Hidenari Yasui

Halophytes are unique in that they can thrive in a wide range of soil conditions, from normal to extremely saline. This has recently prompted researchers to consider using halophytes as a phytoremediation end-product as a source for biogas generation. Therefore, applying the anaerobic digestion process for halophytes may have the potential advantage in terms of efficient land utilization, soil remediation, and biogas production. Based on this, the anaerobic digestion efficiency of high saline biomass was investigated in continuous laboratory-scale anaerobic reactors at two different sludge residence times (SRT) of 40 and 80 days. Under mesophilic atmosphere, two reactors were operated, one reactor used organic substrate with 30 g-Na+.L-1 originating from sodium chloride whereas the other was operated with the presence of sodium bicarbonate and sodium sulfate. The salt-tolerant microorganism was gradually developed and the salt concentrations were selected based on the elemental analyses results of 30 species of wild halophyte plants taken from the saline-affected area of the Aral Sea in Uzbekistan during the early phase of the operation. For 40 and 80 days of SRT, respectively, 65.56 percent and 60.42 percent of the feed COD were converted into methane gas by the chloride system. However, only about 60% of the feed COD was converted into methane for bicarbonate, and the remaining fraction of gas was assigned to sulfide as a final product of increased sulfate reduction bacteria activity. These findings showed that the salt-tolerant microorganism could be incubated and the anaerobic digestion process could be adapted for a high-saline substrate, implying that the biodegradability of phytoremediation end-products may be used for methane production.


Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7449
Author(s):  
Xiali Zheng ◽  
Wei Luo ◽  
Yun Yu ◽  
Zebin Xue ◽  
Yifan Zheng ◽  
...  

A comparative study of the metal emulsion-based synthesis of Sn-based materials in two different types of molten salts (namely LiCl–KCl–CsCl and LiNO3-NaNO3-KNO3 eutectics) is presented, and the properties of Sn, Sn-Cu and Sn-Cu-Zn microsphere phase change materials prepared in chloride salts are evaluated by differential scanning calorimetry (DSC) to understand the effect of element doping. Despite a high ultrasonic power (e.g., 600 W or above) being required for dispersing liquid Sn in the chloride system, well-shaped Sn microspheres with a relatively narrow size range, e.g., about 1 to 15 µm or several micrometers to around 30 µm, can be prepared by adjusting the ultrasonic power (840–1080 W), sonication time (5–10 min) and the volume ratio of salts to metal (25:1–200:1). Such a method can be extended to the synthesis of Sn-based alloy microspheres, e.g., Sn-Cu and Sn-Cu-Zn microspheres. In the nitrate system, however, a very low ultrasonic power (e.g., 12 W) can be used to disperse liquid Sn, and the particles obtained are much smaller. At low ultrasonic power (e.g., 12 W), the particle size is generally less than 10 or 4 µm when the sonication time reaches 2 or 5 min, and at high ultrasonic power, it is typically in the range of hundreds of nanometers to 2 µm, regardless of the change in ultrasonic power (480–1080 W), irradiation time (5–10 min), or volume ratio of salts to metal (25:1–1000:1). In addition, the appearance of a SnO phase in the products prepared under different conditions hints at the occurrence of a reaction between Sn droplets and O2 in situ generated by the ultrasound-induced decomposition of nitrates, and such an interfacial reaction is believed to be responsible for these differences observed in two different molten salt systems. A DSC study of Sn, Sn-Cu, and Sn-Cu-Zn microspheres encapsulated in SiO2 reveals that Cu (0.3–0.9 wt.%) or Cu-Zn (0.9 wt.% Cu and 0.6% Zn) doping can raise the onset freezing temperature and thus suppress the undercooling of Sn, but a broad freezing peak observed in these doped microspheres, along with a still much higher undercooling compared to those of reported Sn-Cu or Sn-Cu-Zn solders, suggests the existence of a size effect, and that a low temperature is still needed for totally releasing latent heat. Since the chloride salts can be recycled by means of the evaporation of water and are stable at high temperature, our results indicate that the LiCl–KCl–CsCl salt-based metal emulsion method might also serve as an environmentally friendly method for the synthesis of other metals and their alloy microspheres.


Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4436
Author(s):  
Elzbieta Radzyminska-Lenarcik ◽  
Ilona Pyszka ◽  
Artur Kosciuszko

This study indicates that a new amine derivative of β-diketone (EDAB-acac) can be successfully used in an acidic medium (HCl) to separate a mixture containing Au(III), Pd(II), and Pt(IV) ions using solvent extraction. The study was conducted in single and ternary model solutions. The impact of acid concentration and the type of solvent (toluene, chloroform, methylene chloride, 2-ethylhexanol) on separation efficiency was discussed. It has been shown that increasing the HCl concentration in the aqueous phase does not favor extraction. In contrast, solvents with high donor numbers (methylene chloride, 2-ethylhexanol) increase both the extraction percentage of Pd and Au as well as the separation coefficients of Pd in relation to Au and Pt. The palladium(II) and gold(III) (which form 4-coordinated planar [MCl4]2− complexes) are extracted most efficiently, Pd(II) (87–93%) and Au(III) (56–62%). The stripping of Au(III), Pd(II), and Pt(IV) ions from the EDAB-acac-methylene chloride phase was also investigated using 0.5 M ammonia aq., mineral acid (5 M HCl, 5 M HNO3), 0.1 M thiourea in HCl and 0.5 M ammonium thiocyanate. A 3-step stripping process was proposed for the recovery of Pd(II), Au(III), and Pt(IV) from the Pd-Au-Pt mixture in the EDAB-acac-methylene chloride system. In the first stage, the aqueous phase is treated with 5 M HNO3 (Pt separation), followed by the application of 0.5 M ammonia (Pd separation) and, finally, 0.1 M thiourea in HCl (Au separation). The solvent extraction with EDAB-acac in acidic medium (HCl) can be used for separation of Pd(II) and Au(III) ions from e-waste leach solutions.


Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 129
Author(s):  
Paweł Mituła ◽  
Czesław Wawrzeńczyk ◽  
Witold Gładkowski

Susceptibility of soybean phosphatidylcholine, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and its phosphono analogue (R)-2,3-dipalmitoyloxypropylphosphonocholine (DPPnC) towards selected lipases and phospholipases was compared. The ethanolysis of substrates at sn-1 position was carried out by lipase from Mucor miehei (Lipozyme®) and lipase B from Candida antarctica (Novozym 435) in 95% ethanol at 30 °C, and the hydrolysis with LecitaseTM Ultra was carried out in hexane/water at 50 °C. Hydrolysis at sn-2 position was carried out in isooctane/Tris-HCl/AOT system at 40 °C using phospholipase A2 (PLA2) from porcine pancreas and PLA2 from bovine pancreas or 25 °C using PLA2 from bee venom. Hydrolysis in the polar part of the studied compounds was carried out at 30 °C in acetate buffer/ethyl acetate system using phospholipase D (PLD) from Streptococcus sp. and PLD from white cabbage or in Tris-HCl buffer/methylene chloride system at 35 °C using PLD from Streptomyces chromofuscus. The results showed that the presence of C-P bond between glycerol and phosphoric acid residue in DPPnC increases the rate of enzymatic hydrolysis or ethanolysis of ester bonds at the sn-1 and sn-2 position and decreases the rate of hydrolysis in the polar head of the molecule. The most significant changes in the reaction rates were observed for reaction with PLD from Streptococcus sp. and PLD from Streptomyces chromofuscus that hydrolyzed DPPnC approximately two times slower than DPPC and soybean PC. The lower susceptibility of DPPnC towards enzymatic hydrolysis by phospholipases D gives hope for the possibility of using DPPnC-like phosphonolipids as the carriers of bioactive molecules that, instead of choline, can be bounded with diacylpropylphosphonic acids (DPPnA).


Minerals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 69
Author(s):  
Arthur Sekisov ◽  
Anna Rasskazova

The geochemical features of the ores present in the oxidation zone of the gold-copper Malmyzh mineral deposit are characterized. This deposit is located in the the Nanaian region of the Khabarovsk Territory in the Russian Federation, and a technological assessment of ores present was carried out. The initial gold content in the oxidized ore is 0.1–1.2 ppm, and the leachability of gold from different size fractions by hot cyanide revealed the fact that the ore is not refractory and characterized by increased cyanide consumption. The results demonstrated a high gold content in fine size fractions. Different leaching reagents were applied for oxidized ore testing. These reagents were used both for oxidative pretreatment and leaching process. Activation of solutions was carried out by electrolysis and UV radiation. Different reagent combinations were tested in laboratory with the highest gold recovery (94%) provided by the chloride system with peroxide-sulfuric pretreatment of the oxidized ore. The same reagent combination resulted in 91–94% gold recovery during the column leaching of crushed (−10 mm) ore.


2020 ◽  
Vol 77 (4) ◽  
pp. 141-168
Author(s):  
Silvia M. Calderón ◽  
Jussi Malila ◽  
Nønne L. Prisle

AbstractWe introduce the CMC based Ionic Surfactant Activity model (CISA) to calculate activity coefficients in ternary aqueous solutions of an ionic surfactant and an inorganic salt. The surfactant can be either anionic or cationic and in the present development, the surfactant and inorganic salts share a common counterion. CISA incorporates micellization into the Pitzer–Debye–Hückel (PDH) framework for activities of mixed electrolyte solutions. To reduce computing requirements, a parametrization of the critical micelle concentration (CMC) is used to estimate the degree of micellization instead of explicit equilibrium calculations. For both binary and ternary systems, CISA only requires binary experimentally-based parameters to describe water–ion interactions and temperature–composition dependency of the CMC. The CISA model is intended in particular for atmospheric applications, where higher-order solution interaction parameters are typically not constrained by experiments and the description must be reliable across a wide range of compositions. We evaluate the model against experimental activity data for binary aqueous solutions of ionic surfactants sodium octanoate and sodium decanoate, as common components of atmospheric aerosols, and sodium dodecylsulfate, the most commonly used model compound for atmospheric surfactants. Capabilities of the CISA model to describe ternary systems are tested for the water–sodium decanoate–sodium chloride system, a common surrogate for marine background cloud condensation nuclei and to our knowledge the only atmospherically relevant system for which ternary activity data is available. For these systems, CISA is able to provide continuous predictions of activity coefficients both below and above CMC and in all cases gives an improved description of the water activity above the CMC, compared to the alternative model of Burchfield and Wolley [J. Phys. Chem., 88(10), 2149–2155 (1984)]. The water activity is a key parameter governing the formation and equilibrium growth of cloud droplets. The CISA model can be extended from the current form to include the effect of other inorganic salts with the existing database of binary PDH parameters and using appropriate mixing rules to account for ion specificity in the micellization process.


Matter ◽  
2020 ◽  
Vol 3 (5) ◽  
pp. 1714-1724
Author(s):  
Kai Liu ◽  
Jialiang Lang ◽  
Minzheng Yang ◽  
Jing Xu ◽  
Bin Sun ◽  
...  

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 253 ◽  
Author(s):  
Giacomo Saielli

We present fully atomistic molecular dynamics (MD) simulations at 450 K of two ionic liquid crystals in the smectic phase: 1-dodecyl-3-methylimidazolium tetrafluoroborate ([C12C1im][BF4]) and 1-dodecyl-3-methylimidazolium chloride ([C12C1im]Cl). The two systems experimentally exhibit different ranges of thermal stability of the ionic smectic phase: The chloride salt has a more stable LC phase, between 270.3 K and 377.6 K, with a range of SmA of more than 107 K. In contrast, the tetrafluoroborate salt has a smectic phase between 299.6 K and 311.6 K, with a range of mesophase of just 12 K. The MD simulations show that the chloride system is stable in the smectic phase for the 5 ns of simulation, while the tetrafluoroborate salt melts into an isotropic ionic liquid, in qualitative agreement with the experiments. Comparison of the electrostatic and van der Waals energetic contributions enables one to rationalize the observed behavior as being due to the large size of the [BF4] anion: a larger size of the anion means a lower charge density, and therefore a weaker electrostatic interaction in the ionic layer.


Author(s):  
Д.Л. Байдаков ◽  
Е.В. Колужникова ◽  
Н.В. Михайлова

Методом химического нанесения из растворов халькогенидных стекол в н-бутиламине получены пленки MnCl2GeS2Ga2S3 и MnSGeS2Ga2S3, исследованы масс-спектрометрические характеристики и изучены электродные свойства пленок. Нанесение халькогенидных пленок осуществляли согласно методике, подробно описанной в Байдаков, Виграненко, 2019. Магнитную восприимчивость в области температур 90293 К исследовали на установке, подробно описанной в Тверьянович, 1978. Измерения проводили в гелиевой атмосфере в режиме дискретного нагревания с термостабилизацией каждой ступени в течение 20 мин Байдакова, 1989. Для регистрации масс-спектров использовали времяпролетный масс-спектрометр типа масс-рефлектрон с разрешающей способностью на половине высоты пика в области массового числа 500 а.е.м., равной 5000. Описание прибора и условия эксперимента приведены в работе Каратаев, Любин, 1988. Ионизацию паров изучаемых образцов осуществляли в источнике ионов с электронным ударом. Обзорные масс-спектры наблюдали в диапазоне энергий 750 эВ. Остаточное давление в камере анализатора составляло 2,7.105 Па. Изготовление электродов на основе мембран халькогенидных пленок и методика электродных измерений подробно описаны в работе Baidakov, Shkolnikov, 2019. Для пленок MnSGeS2Ga2S3 наблюдается значительный рост с увеличением содержания марганца. В сульфидной системе величина 150 К (х 0,25), что свидетельствует о формировании фазы, обогащенной марганцем. Для пленок MnCl2-GeS2-Ga2S3 значение 30 К (х 0,20). С увеличением содержания марганца в хлоридной системе наблюдается рост абсолютной величины константы Вейсса. Из результатов магнитостатического исследования сделано предположение о наличии реакций обмена в пленках MnCl2GeS2Ga2S3. Масс-спектр пленок MnSGeS2Ga2S3 обусловлен диссоциацией трехкомпонентных марганецсодержащих структурных единиц, которым соответствуют соединения состава Mn2GeS4, MnGa2S4, Mn2Ga2S5, Mn3Ga2S6. Наличие спектра пара пленок MnCl2GeS2Ga2S3 только при температурах, превышающих 180 С, существенно отличающегося по составу от исходных пленок, указывает на то, что исходный спектр хлоридной системы обусловлен диссоциацией сульфида германия. Присутствие в масс-спектре фрагментов хлорида германия при 250 С указывает на его наличие в исходных пленках. Это, по-видимому, связано с обменными реакциями в системе MnCl2GeS2Ga2S3. Электроды с пленочными мембранами MnCl2GeS2Ga2S3 показали высокую чувствительность и низкий предел обнаружения катионов Mn2. Нернстовская область электродного отклика лежит в пределах 101106 моль/л нитрата марганца, предел обнаружения достигает 107 моль/л. Электродные свойства халькогенидных стекол и пленок аналогичного состава практически не отличаются. Chalcogenide films MnCl2GeS2Ga2S3 and MnSGeS2Ga2S3 were synthesized from the solutions of chalcogenide glasses in n-butylamine. The mass spectrometric characteristics and electrode properties of films were studied. The application of chalcogenide films was carried out according to the procedure described in detail in Baidakov, Vigranenko, 2019. The magnetic susceptibility in the temperature range 90293 K was studied using a setup described in detail in Tveryanovich, 1978. The measurements were carried out in a helium atmosphere in the mode of discrete heating with thermal stabilization of each stage for 20 min Baidakova, 1989. To record the mass spectra, we used a time-of-flight mass spectrometer of the mass-reflectron type with a resolution at half the peak height in the region of the mass number of 500 amu equal to 5000. A description of the device and experimental conditions are given in Karataev, Lyubin, 1988. Ionization of the vapors of the samples under study was carried out in a source of ions with electron impact. Survey mass spectra were observed in the energy range of 750 eV. The residual pressure in the analyzer chamber was 2,7-105 Pa. The manufacture of electrodes based on chalcogenide film membranes and the method of electrode measurements are described in detail in Baidakov, Shkolnikov, 2019. For MnS-GeS2-Ga2S3 films, a significant increase in with increasing manganese content. In the sulfide system, the quantity 150 K (x 0.25), which indicates the formation of a phase enriched in manganese. For MnCl2GeS2Ga2S3 films, the value 30 K (x 0.20). With an increase in the manganese content in the chloride system, an increase in the absolute value of the Weiss constant is observed. From the results of the magnetostatic study, an assumption was made about the presence of exchange reactions in MnCl2GeS2Ga2S3 films. The mass spectrum of MnSGeS2Ga2S3 films is due to the dissociation of three-component manganese-containing structural units, which correspond to compounds of the composition Mn2GeS4, MnGa2S4, Mn2Ga2S5, Mn3Ga2S6. The presence of the vapor spectrum of MnCl2GeS2Ga2S3 films only at temperatures exceeding 180 C and significantly differing in composition from the starting films indicates that the initial spectrum of the chloride system is due to the dissociation of germanium sulfide. The presence of germanium chloride fragments in the mass spectrum at 250 C indicates its presence in the starting films. This, apparently, is associated with exchange reactions in the MnCl2GeS2Ga2S3 system. MnCl2GeS2Ga2S3 film membrane electrodes showed high sensitivity and low detection limit of Mn2 cations. The Nernst region of the electrode response lies within 101106 mol/l of manganese nitrate, the detection limit reaches 107 mol/l. The electrode properties of chalcogenide glasses and films of a similar composition practically do not differ.


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