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...

[1] The experimental evidence suggests that for many chemicals surface runoff and rapid preferential flow through the shallow unsaturated zone are significant pathways for transport to streams and groundwater. The signature of this is the episodic and pulsed leaching of these chemicals. The driver for this transport is the timing and magnitude of rainfall events which trigger rapid flow and the...

The question of whether or not soil hydraulic parameters of dualpermeability models (DPM) can be properly identified by inverse analysis of preferential water flow data has not been resolved to date. We applied a DPM based on two coupled Richards’ equations to compare the performance of inverse and forward simulations of laboratory preferential flow data. Infiltration and drainage experiments w...

An analytical solution of macrodispersivity was derived for the adsorbing solute transport in physically and chemically heterogeneous unsaturated soils under the condition of gravity-dominated flow. The unsaturated hydraulic conductivity and water content were treated as spatial random functions. The chemical adsorption was described by a linear equilibrium isotherm, and the adsorption coeffici...