Dissolution of iron in sodium chloride solution during alternating current polarization

Iron compounds are widely used in many industries and engineering, and even in medicine. The existing methods of obtaining iron compounds are multi-stage and complex. The purpose of this work is to obtain iron (II) hydroxide and oxide from metal waste under alternating current action using one and two half-cycles. For the first time, the electrochemical behavior of iron electrode was studied by electrolysis method during alternating current polarization of industrial frequency in sodium chloride solutions. The iron polarization was carried out in pair with titanium, while the current density on the iron electrode varied in the range of 200-1200 A/m2, and on the titanium is in the range of 20-100 kA/m2. It is established that in the anode half-cycle of alternating current, iron is oxidized to form divalent ions. At this moment, the titanium electrode is in the cathode half-cycle, hydrogen is released on it, hydroxyl ions are formed in the cathode space. In the solution, ions interact with iron (II) ions to produce iron hydroxide. At temperatures above 600C, iron (II) hydroxide is dehydrated with the production of iron (II) oxide. The electrolysis was carried out in two electrolyzers connected to each other in parallel with the immersion of pair of “titanium-iron” electrodes into each electrolyzer. The iron dissolution occurs simultaneously in two half-cycles of alternating current and this approach is proposed for the first time. The process productivity increases by more than 1.5 times.

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The solubility of iron hydroxide in sodium chloride solutions

Geochimica et Cosmochimica Acta ◽

10.1016/s0016-7037(99)00270-7 ◽

1999 ◽

Vol 63 (19-20) ◽

pp. 3487-3497 ◽

Cited By ~ 190

Author(s):

Xuewu Liu ◽

Frank J Millero

Keyword(s):

Sodium Chloride ◽

Iron Hydroxide ◽

Chloride Solutions ◽

Sodium Chloride Solutions

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ELECTROCHEMICAL BEHAVIOR OF CUPRONICKEL ELECTRODE IN ACIDIC MEDIA

SERIES CHEMISTRY AND TECHNOLOGY ◽

10.32014/2021.2518-1491.5 ◽

2021 ◽

pp. 38-46

Author(s):

R. N. Nurdillayeva ◽

N. Sh. Abdilda ◽

A. B. Bayeshov

Keyword(s):

Aqueous Solution ◽

Hydrochloric Acid ◽

Current Efficiency ◽

Current Density ◽

Kinetic Method ◽

Alternating Current ◽

Solution Temperature ◽

Cycle Duration ◽

Half Cycle ◽

Titanium Electrode

The electrochemical properties of the cupronickel electrode polarized by an alternating current in an aqueous solution of hydrochloric acid were studied for the first time. The electrochemical dissolution of cupronickel was carried out in a polarization mode with a frequency of 50 Hz in pairs with a titanium electrode. The current efficiency of dissolution of Cu-Ni alloys dependence on the current density at the titanium (20-120 kA/m2) and cupronickel (200-1200 A/m2) electrodes, the concentration of a hydrochloric acid solution (0.5-5.0 M), the electrolysis duration (0.5-1.75 h) and the alternating current effect (50-300 Hz) were considered. It was observed that the current efficiency of the alloy dissolution decreases linearly with increasing current density at the cupronickel electrode, while the current density at the titanium electrode passes through a maximum value at 60 kA/m2. The dependence of the alloy dissolution on the acid concentration was studied, and the reaction order was calculated. The reaction orders for the formation of copper (I) and nickel (II) ions accounted for 0.95 and 0.85, respectively. As the frequency of the alternating current increased, the current efficiency of the cupronickel electrode dissolution changed significantly. It has been shown that high current frequencies do not provide the required anodic half-cycle duration for the oxidation reaction of the metals, as the periods change very rapidly. It was found that electrolysis is effective at a frequency of 50 Hz AC. It was observed that the dissolution rate of the copper-nickel alloy increases with increasing solution temperature. It was found that the dissolution of cupronickel in an aqueous solution of hydrochloric acid by the temperature-kinetic method takes place in the diffusion-kinetic mode. Ideally, the current efficiency values were 59% for Cu (I) ions and 15% for Ni (II) ions.

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Axial Compressor Mean-Line Analysis: Choking Modelling and Fully-Coupled Integration in Engine Performance Simulations

International Journal of Turbomachinery Propulsion and Power ◽

10.3390/ijtpp6010004 ◽

2021 ◽

Vol 6 (1) ◽

pp. 4

Author(s):

Ioannis Kolias ◽

Alexios Alexiou ◽

Nikolaos Aretakis ◽

Konstantinos Mathioudakis

Keyword(s):

Axial Compressor ◽

Engine Performance ◽

Engine Model ◽

Multi Stage ◽

Transient Simulations ◽

Full Knowledge ◽

Compressor Performance ◽

First Time ◽

Performance Calculation ◽

Fully Coupled

A mean-line compressor performance calculation method is presented that covers the entire operating range, including the choked region of the map. It can be directly integrated into overall engine performance models, as it is developed in the same simulation environment. The code materializing the model can inherit the same interfaces, fluid models, and solvers, as the engine cycle model, allowing consistent, transparent, and robust simulations. In order to deal with convergence problems when the compressor operates close to or within the choked operation region, an approach to model choking conditions at blade row and overall compressor level is proposed. The choked portion of the compressor characteristics map is thus numerically established, allowing full knowledge and handling of inter-stage flow conditions. Such choking modelling capabilities are illustrated, for the first time in the open literature, for the case of multi-stage compressors. Integration capabilities of the 1D code within an overall engine model are demonstrated through steady state and transient simulations of a contemporary turbofan layout. Advantages offered by this approach are discussed, while comparison of using alternative approaches for representing compressor performance in overall engine models is discussed.

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Efficacy of compressed sodium chloride (CSC) against E. coli and Candida auris in minutes and methods improvement for testing

Scientific Reports ◽

10.1038/s41598-020-79212-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Lan N. Truong ◽

Brayden D. Whitlock

Keyword(s):

Sodium Chloride ◽

Improved Method ◽

Candida Auris ◽

Antimicrobial Surfaces ◽

E Coli ◽

Route Of Transmission ◽

The World ◽

Short Time ◽

First Time ◽

Time Point

AbstractControlling infections has become one of the biggest problems in the world, whether measured in lives lost or money spent. This is worsening as pathogens continue becoming resistant to therapeutics. Antimicrobial surfaces are one strategy being investigated in an attempt to decrease the spread of infections through the most common route of transmission: surfaces, including hands. Regulators have chosen two hours as the time point at which efficacy should be measured. The objectives of this study were to characterize the new antimicrobial surface compressed sodium chloride (CSC) so that its action may be understood at timepoints more relevant to real-time infection control, under two minutes; to develop a sensitive method to test efficacy at short time points; and to investigate antifungal properties for the first time. E. coli and Candida auris are added to surfaces, and the surfaces are monitored by contact plate, or by washing into collection vats. An improved method of testing antimicrobial efficacy is reported. Antimicrobial CSC achieves at least 99.9% reduction of E. coli in the first two minutes of contact, and at least 99% reduction of C. auris in one minute.

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