Concentration polarisation

Diffusive transport of a substance through a membrane separating solutions of different concentrations leads to the formation of concentration boundary layers (CBLs) adjacent to its surfaces. This phenomenon, commonly referred as concentration polarisation, causes the permeability coefficient measur

Two 2D models of non-stationary and non-isothermal transfer of a strong binary electrolyte in a rectangular electrodialysis desalination cell formed by anion- and cation-exchange membranes are developed. Both gravitational and forced convection occurring in underlimiting current mode are taken into

A theoretical investigation of particle deposition onto a permeable surface of a tubular membrane is presented. The mass transport mechanisms are mathematically expressed using the two-dimensional convective diffusion equation. A numerical scheme is presented to solve the two-dimensional convective

One of the major problems associated with membrane separation processes, which restricts the widespread application of this process in the industry is the decline in flux. This occurs due to the build up of the solute concentration near the membrane surface, which is defined as concentration polaris

The emf method has been compared with the conductometric one in determining the apparent electrolyte permeability of membrane ( ). It has been found that this method is limited to the membranes of low permeability ( of the order 10!7 m/s). In order to obtain the real permeability coefficient (Ps), t

The key to developing highly efficient spiral-wound modules is the improvement of the mass transfer mechanisms. In this study a study of the mass transfer has been carried out using a flat test cell with six permeate outlets and a rectangular feed channel. Using this experimental set-up, it has been

A detailed study on concentration polarisation during microfiltration (MF) was carried out in order to improve control on cake layer formation. Concentration polarisation is reduced by several back-transport mechanisms, however, for particles in the size range 0.5–30 µm shear-induced diffusion is th

While models of membrane systems with varying degrees of complexity have been developed since the early 1960s, reports of the use of computational fluid dynamics to provide in-depth insights into the separation phenomenon have only recently appeared in the literature. This paper describes the valida