This second part of the overview of reverse osmosis investigates the ability of membrane transport models, presented in Part 1, to describe and/or predict membrane performance under different operating conditions. The problem of using the transport models to describe mixed solute systems is also discussed. The emphasis is to provide a simple, practical, and yet comprehensive summary of the most...

The current concept of fluid transport in vertebrates is that water moves passively down the osmotic gradient created by an active transport of solute. Earlier suggestions that these tissues could transport water in the absence of a concomitant movement of solute have been rejected (Curran, 1965; Diamond, 1965; Robinson, 1965, 1966). Interest is now focused on the mechanism by which water movem...

Knowing the overall solute flux and the partial fluxes expressed by every single transport layer, the membrane internal interface concentrations can separately be expressed. Both the overall transport coefcient and the driving force strongly depend, among others, on the value of the structural parameter and the water permeability. Study of the interface concentrations as ...

A finite-element approach was formulated, aimed at enabling an integrated study of mechanical and biochemical factors that control the functional development of tissue engineered constructs. A nonlinear biphasic displacement-velocity-pressure description was combined with adjective and diffusive solute transport, uptake and biosynthesis. To illustrate the approach we focused on the synthesis an...

Solute transport in soils is commonly simulated with the advective-dispersive equation, or ADE. It has been reported that this model cannot take into account several important features of solute movement through soil. Recently, a new model has been suggested that results in a solute transport equation with fractional spatial derivatives, or FADE. We have assembled a database on published solute...

Peritoneal solute transport increases with time on treatment in a proportion of peritoneal dialysis (PD) patients, contributing to ultrafiltration failure. Continuous exposure of the peritoneum to hypertonic glucose solutions results in morphologic damage that may have a causative role in changes in peritoneal function. The purpose of this analysis was to establish whether increased exposure to...

advection-diffusion equation and its related analytical solutions have gained wide applications in different areas. compared with numerical solutions, the analytical solutions benefit from some advantages. as such, many analytical solutions have been presented for the advection-diffusion equation. the difference between these solutions is mainly in the type of boundary conditions, e.g. time pat...

A stream solute workshop was held February 1-5,1989, at The University of Mississippi with the goals of 1) suggesting a conceptual model for stream solute studies that integrates physical, chemical, and biological processes, and 2) identifying advantages and limitations of various methods for studying solute transport and exchanges. Solute dynamics refers to the spatial and temporal patterns of...

dispersivity (?) and effective transport porosity (?eff) are input parameters in equilibrium convection dispersion equation (cde). normally these parameters are obtained from breakthrough curves by inverse method. however, obtaining breakthrough curves in the field is not often possible in practice. the objective of this study was to estimate ? and feff from soil hydraulic data. for this purpos...