Water treatment before use - Systems and applications

The two previous articles examined the various standalone treatment processes for particulate matter [G 1 170] and dissolved substances [G 1 171] . We will now look at how these processes can be combined into more or less complex treatment systems, the purpose of which may sometimes be limited to simple water clarification and disinfection, while in other cases, it will also be necessary to provide for further refinement (removal of micropollutants and improvement of organoleptic characteristics), reduction of water hardness through lime decarbonation or resin softening, and demineralization using ion exchange resins and/or membranes—to mention only the general treatments; more specific treatments may also be required, such as the removal of certain dissolved gases (O ₂ , N ₂ , CO ₂ , H ₂ S), iron and manganese, ammonium or nitrates, etc.

This article therefore provides a description of how unit processes are organized into treatment streams and the applications they can have in various industries. It is obviously not possible to cover the subject exhaustively, given the great diversity of:

• water resources (including seawater and brackish water, when they are readily available and their use is feasible); in some cases, a manufacturer may also opt for only supplementary treatment if connected to the drinking water supply; the following primarily concerns the treatment of natural freshwater, whether from surface or groundwater sources; For seawater or brackish water desalination techniques, see [W 5 700] ; another type of resource, already discussed in the article