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Charge-Modified Filter Media
Published in Maik W. Jornitz, Filtration and Purification in the Biopharmaceutical Industry, 2019
Eugene A. Ostreicher, Todd E. Arnold, Robert S. Conway
Streaming potential is the electric potential that is developed when a liquid is forced through a capillary or a network of capillaries such as a microporous membrane. It is due to the pressure drop across the end of a capillary or a porous plug such as a microporous membrane containing a liquid. The fluid flow created by the pressure drop across the capillary creates a disturbance in the electrical double layer, which sets up an electric potential across the ends of the capillary or porous medium. This potential can be measured directly by using a pair of inert electrodes in an external circuit of high impedance, so that all the current is forced to flow back through the system being measured, in this case a capillary. An apparatus for measuring streaming potential on a charged glass capillary is shown in Figure 2.8. It should be obvious from Figure 2.8 that a simple test apparatus can easily be assembled to evaluate the charge characteristics of filter material, whether it is a microporous membrane, felted filter medium, or granular material.
Fundamentals of Microscale Convection
Published in C. B. Sobhan, G. P. Peterson, Microscale and Nanoscale Heat Transfer, 2008
The streaming potential is the potential of the electric field generated when a liquid is forced through a channel under hydrostatic pressure (Mala et al. 1997). The zeta potential, which is the electrostatic potential at the interface of the electric double layer, can be calculated using the channel height and the volume flow rate of the fluid. The procedures for determining the streaming potential and the zeta potential in a practical flow situation are elaborated in Mala et al. (1997) and will not be discussed here. The velocity distribution has been used in calculating the friction coefficients, as well as in the solution of the energy equation to obtain the Nusselt number by Mala et al. (1997), in their excellent work. The readers are referred to these for a complete analysis of the problem and the procedure discussed above. Variation of the local Nusselt number along the channel length and the average Nusselt number as a function of the Reynolds number obtained from the analysis are shown in Figures 3.4 and 3.5.
Advanced Nanofiltration Membranes for Wastewater Treatment
Published in Pankaj Chowdhary, Abhay Raj, Contaminants and Clean Technologies, 2020
Oluranti Agboola, Samuel E. Sanni, Rotimi Sadiku, Patricia Popoola, Victoria Oluwaseun Fasiku
Studies have revealed that the electrical surface characteristics of membranes, such as streaming potential and surface charge density, have great influence on nature and extent of membrane fouling instigated by the membrane–particle interfacial interactions (Salgın et al., 2013), solute retention (Luxbacher et al., 2014), and water permeability (Saksena and Zydney, 1995). Usually, the streaming potential is employed to assess the zeta potential, which is an estimation of the extent of electrostatic interactivities amid charged surfaces. It is the potential at the shear plane amid the solid stratum that is present with the pore wall and the mobile diffusion stratum on the surface of the membrane pores (Jing et al., 2013). This potential is created at the interface of a solid and a neighboring liquid, which denotes the surface charge that transpires in the presence of an aqueous solution when functional groups dissociate on surface or ions adsorb onto surfaces from the solution (Sathappa and Alder, 2016). Hence, together with the direct correlation between the zeta potential with salt rejection, water permeability, and the nature of fouling, zeta potential is a vital indicator for surface functional groups. These surface functional groups are hydrogen–carbon chemical entities of the membrane surface, for example, carboxylic acid, which render the surface acidic, amphoteric, or basic (Luxbacher et al., 2014). These functional groups are the reasons for the charge creation. Apart from streaming potential, zeta potential could be measured by electroosmosis, sedimentation potential, electrophoresis, and potentiometric titration method.
Numerical analysis of streaming potential induced by loads in micro-pores of articular cartilage
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2022
Yutao Men, Yucheng Ren, Zhonghai Zhao, Xin Wang, Lu Liu
The cartilage solid matrix has negatively charged ions, and the wall of the cartilage matrix will more or less absorb the counter ions in the interstitial fluid. A electric double layer (EDL) is formed at the solid-liquid junction (Lee et al. 1981; Grodzinsky 1983; Frank and Grodzinsky 1987b) (Figure 1(a)). When the cartilage is subjected to a certain external force, the interstitial fluid of the cartilage pores will move tangentially along the surface of the cartilage matrix, while driving the ions to flow to the other end in the direction of flow. There is a kind of current, called streaming current (IS), and the streaming current generated by the pressure gradient, it will generate an induced electric field along the flowing direction (Grodzinsky 1983; Frank and Grodzinsky 1987b). The existence of the induced electric field causes the heterogeneous ions in the diffusion layer to move in the direction opposite to the direction of the pressure gradient. Accordingly, a current opposite to the flowing direction is generated, which is called conduction current (IC). When these two currents are equal, an equilibrium state will be reached, and the potential will also reach a stable value. This steady-state potential is called the streaming potential. Figure 1(b) shows the cause of streaming potential in the pores of cartilage micro-element.
Synergistic SmartWater based surfactant polymer flooding for enhanced oil recovery in carbonates
Published in Petroleum Science and Technology, 2022
Jinxun Wang, Subhash C. Ayirala, Abdulkarim Sofi, Ali Yousef
The zeta potentials were measured using ZetaCAD-HT, CAD instrument, France. Tests were conducted using carbonate reservoir cores with both HSW and SmartWater at the elevated temperature of 60 °C using streaming potential method. It was not possible to perform the measurement at reservoir temperature as it exceeds the upper temperature specification limit of the instrument. The electrolyte is forced through the core in this technique to measure the potential across the core when a steady state is established, which is called as “streaming potential (E).” The differential pressure across the core (P) and electrical conductivity (λ) of the solution is also measured. The zeta potential (ζ) is then calculated from the slope of the streaming potential versus the pressure line using the classic Helmholtz–Smoluchowski equation, where ε is the permittivity and η is the viscosity of the brine solution, respectively.
Nylon fibers coated with diclofenac: adsorption properties
Published in The Journal of The Textile Institute, 2019
E. Giménez-Martín, M. A. López-Andrade, D. Campos
where: ΔU streaming potential; Δp pressure difference; conductivity of the electrolyte solution; dynamic viscosity of electrolyte solution. Zeta potential has been determined by streaming potential with an Electrokinetic Analyzer, EKA, (Anton Paar, KG). Samples of 1 g of fiber were placed between two electrodes at a constant distance of 1 cm of a cylindrical cell of 20 mm diameter, which corresponds to a bulk sample density inside the cell of approximately .32 g/cm3. An electrolyte solution of 1 mM KCl is forced to stream along the solid surface by a pressure difference, and the flow changes its direction periodically. The streaming potential is measured with two electrodes Ag/AgCl placed at both sides of the sample. Data are obtained by the average value of tree measurements.