Purpose of physico-chemical treatments
Physico-chemical treatment of insoluble pollution

Almost all industrial effluents contain insolubles in highly variable proportions:

• more or less dispersed solid particles ;

• water-immiscible liquids in free form or in emulsion.

These compounds, which are responsible for turbidity and discoloration of wastewater, differ in nature (organic or mineral) and characteristics, in particular density and particle size, which can vary widely.

Figure 1 shows the various physico-chemical treatments applicable to industrial effluents, based on the approximate size of insoluble elements.

Generally speaking, any pollution control treatment ensuring the elimination of insolubles includes :

• preliminary treatments or pre-treatments, which consist of a number of mechanical...