4.1 The need to understand the relationships found in membrane unit processes for water treatment increases with the continuing demand for these separation systems. Defining the terms common to microfiltration, ultrafiltration, nanofiltration, and reverse osmosis processes assist the manufacturer, consultant, and end-user in eliminating inter-process terminology confusion. This standard expands the definitions found in Terminology D1129.

1.1 This terminology covers the use of microfiltration, ultrafiltration, nanofiltration, and reverse osmosis for membrane separation processes.

1.2 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.