Water treatment before use. Dissolved substances

The previous article, " [G 1 170] ," focused on the removal of all suspended particulate matter from natural water sources. These treatments, known as "clarification," may be sufficient for preparing industrial water when quality standards are not very stringent (e.g., certain types of wash water, transport water, or cooling water; water from cardboard and packaging paper manufacturing facilities).

In many cases, however, treatment must be taken a step further, removing oxidizable organic matter that is poorly or not at all biodegradable (generally analyzed by COD, TOC, etc.), nitrogen-based macro-pollutants (nitrates, ammonium, etc.), metals and other non-metallic mineral compounds, mineral and organic micropollutants, certain gases, etc., sometimes requiring disinfection to produce drinking-quality water, and in the most advanced cases, achieving a product as close as possible to the element H ₂ O (“ultrapure water”).

This article therefore reviews all physicochemical treatment processes (biological treatments are not covered here; see [G 1 300][G 1 305][W 2 703] , [IN 44] ) that affect all dissolved constituents (gases, mineral salts, organic matter, and various pollutants). Some of these processes...