Concentration polarization

The parameters of the model comprising the polarization layer and the Spiegler–Kedem–Katchalsky model of membrane transport were determined for a series of nanofiltration membranes. Membranes with different NaCl retentions were chosen. The experiments were performed at the same hydrodynamic conditio

Textile industries consume large amounts of water and generate highly dye-contaminated effluents. Textile wastewaters have to be treated in order to be recycled in the process or to meet legislative requirements before being discharged. The objective of the present study was to examine the potential

Rotating reverse osmosis (RO), which is based on Taylor-Couette flow, offers a means to minimize flux decline due to concentration polarization and membrane fouling. However, the operating conditions play a significant role in determining the effectiveness of the system. In this study, the effect of

In cross-flow ultrafiltration permeate flux has three types of flow regimes. Initially it has a transient regime with a decreasing permeate flow rate. Then it attains a steady state, and the flux reaches a plateau. In the third stage the flow rate becomes independent of applied pressure and is calle

A mathematical model of the competitive electro-transport of two counter-ions through an ion exchange membrane based on the Nernst-Planck and Poisson equations is developed. A three-layer system is considered: the membrane and two adjacent diffusion layers. Concentration profiles in the three layers

Reverse osmosis (RO) is an efficient process for the removal of ionic and organic pollutants from contaminated water. In this study, rotating RO, which takes advantage of Taylor-Couette flow instabilities to reduce the flux decline related to concentration polarization and membrane fouling, was inve

A theoretical analysis of the effect of random fiber packing on shell flow distribution, associated shell-side concentration boundary layers, and ultimate performance of shell-fed hollow-fiber gas separation modules is presented. Specifically the relationship between recovery and product oxygen mole

A primary reason for flux decline during the initial period of a membrane separation process is concentration polarization of the solute at the membrane surface. The objective of the present study was to analyze and model concentration polarization in spiral-wound seawater membrane elements. In part

The laminar flow structure and concentration distribution in a narrow rectangular channel simulating the feed channel of nanofiltration (NF) spiral-wound modules are investigated. The continuity, Navier–Stokes equations and the solute continuity equation are solved by the control volume formulation.

The objective of the present study was to analyze and model concentration polarization in spiral-wound seawater membrane elements. In particular, the influence of feed temperature, salinity and flow rate on permeate flow and salinity was evaluated. Membrane lifetime and permeate fluxes are primarily