Conductivity Of Distilled Water Research Articles

Hydrogen Production by Water Electrolysis with Low Power and High Efficiency Based on Pre-Magnetic Polarization

In this paper, a method of efficient hydrogen production using low-power electrolysis based on pre-magnetic polarization was proposed in order to improve the rate of hydrogen production by water electrolysis, with reduced energy consumption, molecular polarity, and stress–strain characteristics of distilled water under the condition of a pre-magnetic field. By constructing a microphysical model of hydrogen proton energy-level transition and a macroscopic mathematical model corresponding to magnetization vector-polarization hydrogen proton concentration in the pre-magnetic field, the ionic conductivity, electrolyte current density, interelectrode voltage, and hydrogen production efficiency under a varying magnetic field were qualitatively and quantitatively analyzed. In addition, an adjustable pre-magnetic polarization hydrolyzing hydrogen production test platform was set up to verify the effectiveness of the proposed method. The repeated test results, within a magnetic field strength range of 0–10,000 GS, showed that the conductivity of distilled water after pre-magnetic polarization treatment increased by 2–3 times, the electrolytic current density of the PEM (Proton Exchange Membrane) increased with increasing magnetic field strength, the voltage between the poles continuously decreased, and the hydrogen production rate was significantly improved. When the magnetic field strength reached 10,000 GS, the rate of hydrogen production by the electrolysis of distilled water increased by 15–20% within a certain period of time.

Salinity of flowback fracturing fluid in shale reservoir and its reservoir damage: Experimental and field study

In order to study the salinity of fracturing fluid flowback from shale gas wells and its damage to reservoirs, shale gas wells in PS (Peng Shui) and CN (Chang Ning) areas of Sichuan Basin (China) were taken as research objects in the current work. Immersion experiments of shale particles and single mineral particles were carried out using distilled water. The conductivity of distilled water during immersion was monitored using a conductivity meter, and the ionic composition and the content of immersed fluid were analyzed using ion chromatograph and atomic absorption spectrophotometer. Meanwhile, the flowback fracturing fluids from shale gas wells in PS and CN areas of Longmaxi reservoir in Sichuan Basin, China were collected, and their salinity and composition were analyzed. The results of shale particle immersion experiments showed that the mass concentration of salt in shale was 1 mg salt/g of shale. Furthermore, the salinity of flowback fracturing fluid was found to be about 30,000 mg/L. Compositional analyses of shale particle immersion fluid and field flowback fluid show that the contents of Na+ and Cl− in shale reservoir are the highest. The analysis of field flowback fracturing fluid in shale gas wells shows that the salinity of flowback fracturing fluid is much higher than that of fracturing fluid. High salinity flowback fracturing fluid would produce salt crystals in the later stage of flowback and production stage, blocking fractures and pores, and reducing gas seepage capacity.

Electrical Properties of Dead Sea Water

In this paper, dielectric measurements were carried out to obtain conductivity, permittivity (real and imaginary parts) and loss tangent of Dead Sea water. These dielectric properties were measured using two different methods: Vector Network Analyzer “VNA” (Dielectric Assessment Kit “DAK”) and Four Probe method, all measurements taken at room temperature (25˚C). The collected data has been analyzed in the frequency range (200 MHz - 9 GHz), by making a comparison between the measured data for Dead Sea water and distilled water, the results have shown that a huge difference in dielectric properties for the two samples. The conductivity of Dead Sea water is much larger than the conductivity of distilled water, which has been expected because of the fact of the high salinity of Dead Sea water.

Features of Measuring the Electrical Conductivity of Distilled Water in Contact with Air

The paper describes the results of experiments on measuring the electrical conductivity (specific conductance) of distilled water during prolonged contact with air. To carry out the experiments, a hardware-software complex was developed and manufactured that made it possible to measure the electrical conductivity of water with a relative error of the order of ±0.1% with a change in its temperature within 2–50°C, and a temperature error of ±0.06°C. It is shown that the time of diffusion and dissolution of carbon dioxide in water significantly affects the time dependence of the specific conductance of water when its temperature changes. The peculiarity of measuring the electrical conductivity of distilled water for open and closed systems is shown in the results of experiments with partially and completely filled conductometric cells. Thus, in a filled cell in the absence of gas exchange between water and air, the temperature coefficient of electrical conductivity of water is close to the known table value. In this case, in an empty cell, the gas exchange process significantly reduces the value of this coefficient, and the degree of decrease is proportional to the exposure time between the temperature setting and the moment of conductivity measurement. The experimental results are supplemented by theoretical dependences of the specific conductance of water on temperature for various gas exchange conditions between water and air. It is also shown that when measuring the temperature coefficient of electrical conductivity of distilled water in contact with air, it is necessary to take into account not only the time of dissolution of carbon dioxide in it, but also the design features of the electrolytic cell.

Variations of Proton Mobility in Distilled Water

Variations in the electrical conductivity of distilled water were studied experimentally at constant water temperatures. When the concentrations of major ions in water remained constant, proton mobility was found to display daily variations with a coefficient of variation reaching 15% of the initial value. The amplitude of the variation was observed to depend on the water temperature. Possible mechanisms of the observed effects are discussed.

Features of measuring the electrical conductivity of distilled water in contact with air

Features of measuring the electrical conductivity of distilled water in contact with air

Manifestation of Solar–Terrestrial Rhythms in Variations of the Electrical Conductivity of Water

Variations of electrical conductivity of distilled water were continuously measured for 1 month. Long-period (up to 7 days or longer) variations were observed in electrical conductivity of water. The effect of temperature on the conductivity was minimized methodically and analytically. Temporal variations in distilled water conductivity were periodically observed to correlate with the intensity of solar radiation at a wavelength of 10.7 cm and variations in atmospheric pressure and global magnetic indices. Possible causes of the phenomena are discussed.

Slow variations of the electroconductivity of distilled water

The conductivity of distilled water with a slow change in temperature has been measured experimentally and studied. Periodic variations in the electrical conductivity of water have been found, which are observed at the rate of temperature change dT/dt < 0.1 K/h. The periods were longer than 24 h; the amplitudes of the variation ranged from +2.7% to–2.3%. The possible causes of the observed phenomena are discussed.

Energy transformation in water and oxygen-containing electrolytes

The conductivity of distilled water and dilute electrolyte solutions in the presence and absence of dissolved oxygen is studied. It is found that the circuit can be implemented with equal probability as a capacitive circuit with physically different current carriers and as an inductive circuit in water and dilute aqueous solutions of oxygen-containing electrolytes. The occurrence of an inductive resistance is caused by the presence of particles with intrinsic magnetic moment, i.e., reactive oxygen species. The frequency ranges of possible pulse energy transformation in an electrochemical system that contains oxygenated water are shown. In the absence of oxygen, this circuit is not implemented.

Electrodialytic boron removal from SWRO permeate

The electrodialytic removal of boron from seawater reverse osmosis permeate was examined in laboratory. Two model SWRO permeates were investigated. The composition of the first one (TDS 604 mg/L, B content 2.25 mg/L) was calculated using ROSA 6.0 software (DOW Chem.) assuming SW30HR-320 membrane, ocean seawater feed composition and 40% water recovery. The composition of the second one (TDS 400 mg/L, B content 1.3 mg/L) was calculated assuming higher membrane rejection. An ED unit, equipped with AMX and CMX Neosepta (Tokuyama Co.) membranes and 0.4 mm membrane-to-membrane distance, was applied. In both cases the ED processes were carried out to decrease the B content down to 0.4 mg/L. At the same time the RO permeate was almost completely deionized to diluate conductivity been ca. 0.7 μS/cm that is less than the distilled water conductivity. The boron current efficiency reached 10.4% and boron flux across membrane 15.2 μg/cm 2 h in the first case and respectively: 4.6% and 11.3 μg/cm 2 h in the second. The energy consumption was very low and equal to 0.237 kWh/m 3 (0.186 kWh/m3) and the estimated cost of boron removal was found to be promising.

An approach to estimate the sputtering yield of water in glow-discharge electrolysis

When a high positive voltage is applied to the electrode above the negative liquid surface, glow-discharge is generated between the electrode and the liquid surface under reduced pressure. Bombardment of the water surface by energetic projectiles in glow-discharge electrolysis (GDE) leads to ejection of atoms and molecules from the water surface as Hickling reviews [1]. Although sputtering in GDE could be applied to film formation of oxide and diamond [2–4], virtually nothing is known about the sputtering yield of water. The collisional process occurs in the 100–1000 μm thick cathode sheath with a cathode drop of about 400 V [5]; the process increases the number of projectile by charge transfer [6]. The projectile energy distribution is likely to be very broad and even the average projectile energy is unknown under the typical GDE conditions. In our previous investigation, sputtering yield of water was deduced from the liquid loss assuming that the loss is totally due to the sputtering [7]. While, in the course of another experiment, we were obliged to admit that the water loss is due not only to the sputtering but also to the local heating of water and subsequent evaporation. How can we estimate the water loss due to sputtering excluding the effect of thermal evaporation? This work reports an approach to distinguish the sputtering from the thermal vaporization. Sputtering was carried out in a fused quartz glass chamber of 5 cm diameter as illustrated in Fig. 1. The positive electrode was a tungsten wire of 0.5 mm diameter. Water was biased negatively via graphite block. The electrode-liquid distance was 8 mm and the liquid layer thickness was 20 mm. The initial conductivity of distilled water was adjusted to about 60 μS/cm by adding a small amount of HCl. Prior to experiment, the water was evacuated for 1 h for degassing. Hydrogen gas was introduced in the chamber at a flow rate of 100 sccm. The pumped up water led to the surface water flow by overflowing the water into the reservoir. The circulation rate of the pump varied between 50 and 188 ml/min. The water loss was obtained from the difference in the water level in the measuring cylinder at 293 K under atmospheric pressure. First of all, the operational error and the amount of the evaporation at 293 K under 13 kPa (100 Torr) were evaluated. The operational error includes the error due to the thermal expansion of water. The water was circu-

Thermal conductivity measurements of non-Newtonian fluids in a shear field

An investigation was carried out to determine experimentally the thermal conductivities of non-Newtonian fluids in a shear field. Both time independent purely viscous and viscoelastic fluids were considered. A coaxial cylinder apparatus with a rotating outer cylinder was used to establish the velocity field in the test fluid. First, the thermal conductivity of distilled water measured to validate the instrument. The experimental water data agreed within 1% of literature values and there was no effect of outer cylinder rotation (shear field). However, for non-Newtonian fluids such as aqueous CMC and Separan solutions, there were significant increases in thermal conductivities of up to 70% for CMC and 50% for Separan depending on the shear rate, polymer concentration and temperature. Considering the shear rate dependent thermal conductivity in the study of heat transfer in non-Newtonian fluids could be important. As in natural convection, the momentum and energy equations could no longer be solved separately but would have to be solved simultaneously.

Experimental research on electrostatic voltmeters

The paper describes briefly various experimental work performed with the object of reducing the range of an electrostatic voltmeter. It was hoped to use water as the dielectric ( = 80) in order to increase the torque and so lower the full-scale voltage. The conductivity of distilled water was found to be far too high, however. Methyl alcohol ( = 34) was also tried and abandoned for the same reason. Experiments were made on a cylindrical vane-type of electrostatic voltmeter in paraffin. Under certain conditions the increase in scale for a given voltage was approximately proportional to the dielectric constant of the paraffin. Unless care is taken the mechanical properties of the liquid swamp the electrical force entirely. Another design of instrument with a constrained-strip suspension was tried and found to have its calibration directly proportional to epsilon, the mechanical effects being eliminated. The reduction of voltage for full-scale was only 1/√2 however, and hardly appreciable.