Mechanism of Osmotic Flow in Porous Membranes

Osmotic Flow of Water across Permeable Cellulose Membranes

Direct measurements have been made of the net volume flow through cellulose membranes, due to a difference in concentration of solute across the membrane. The aqueous solutions used included solutes ranging in size from deuterated water to bovine serum albumin. For the semipermeable membrane (impermeable to the solute) the volume flow produced by the osmotic gradient is equal to the flow produc...

Mechanism of osmotic flow in a periodic fiber array.

The classic analysis by Anderson and Malone (Biophys J 14: 957-982, 1974) of the osmotic flow across membranes with long circular cylindrical pores is extended to a fiber matrix layer wherein the confining boundaries are the fibers themselves. The equivalent of the well-known result for the reflection coefficient sigma0 = (1 - phi)2, where phi is the partition coefficient, is derived for a peri...

Effects of charge on osmotic reflection coefficients of macromolecules in porous membranes.

A computational model was developed to predict the effects of solute and pore charge on the osmotic reflection coefficients (sigma(o)) of spherical macromolecules in cylindrical pores. Results were obtained for particles and pores of like charge and fixed surface charge densities, using a theory that combined low Reynolds number hydrodynamics with a continuum, point-charge description of the el...

Characterization of Porous Membranes

Mechanisms Involved in Osmotic Backwashing of Fouled Forward Osmosis (FO) Membranes

Organic matter leads to one of the biggest problems in membranes: fouling. Developing efficient cleaning processes is therefore crucial. This study systematically examines how alginic acid fouling formed under different physical and chemical conditions affect osmotic backwashing cleaning efficiency in forward osmosis (FO). The fouling layer thickness before and after osmotic backwashing was mea...