Chapter 4 - Transport Models, Membrane Materials, and Basic Flow Patterns

Abstract

Proper understanding of the reverse osmosis (RO) system operation is essential for developing theoretical models outlining the transport of water and solutes through the reverse osmosis membrane. By the accurate knowledge of how water and solutes are transported across the membranes, suitable modifications could be carried out in the membrane systems for improving the performance (water flux and salt rejection). This chapter concisely covers the transport models, which describe the flow of water and salt in the reverse osmosis system, such as nonporous models, porous models, and irreversible thermodynamic models. Also we discuss in detail the basic membrane materials, their preparation methods, different module configurations, and how they are arranged. Moreover understanding of the flow patterns for reverse osmosis systems is important for the proper functioning of a reverse osmosis system. Arrays, recycle, double pass, and multiple trains are the different flow patterns employed in a reverse osmosis system. Also various seawater reverse osmosis system configurations and hybrid reverse osmosis desalination systems are described.