Reverse Osmosis and Nanofiltration
|Publication Date:||1 January 2007|
This first chapter provides a general introduction to the reverse osmosis (RO) and nanofiltration (NF) membrane treatment processes. The subjects addressed in this chapter should serve as the basic foundation for a broader understanding of RO and NF processes as applied to potable water, industrial process water, tertiary wastewater, and reclaimed water treatment, and include a general overview of the technology (i.e., types of processes, history of development, general RO/NF system description, and typical performance), specific applications, and membrane materials and configurations. Successive chapters will build on these concepts to provide more detailed information about process design (chapter 2), facility design and construction (chapter 3), and operations and maintenance (O&M) (chapter 4). For readers unfamiliar with RO and NF, a typical facility is shown in Figure 1-1. This picture shows the 10-mgd Scottsdale Water Campus, an RO system treating reclaimed water for aquifer recharge. The RO process itself consists of numerous skids with long horizontal pressure vessels containing the membrane elements, as shown in the center of the picture. The prefiltration (i.e., cartridge filters) to remove particulate matter upstream of the RO process is shown in the foreground at the bottom of the picture, and the high pressure pumps are aligned along the left side.