1. Clarification presentation

Clarification is the removal of suspended solids, colloidal matter and macromolecules that can impart undesirable turbidity or color to water. This includes organic as well as mineral matter, and the living organisms of phytoplankton (algae) and zooplankton are also included in this definition.

Two categories of process can be distinguished.

• Physical treatments

  They are used for simple mechanical solid-liquid separation, without the introduction of reagents:

  • screen (if possible, self-cleaning screen) ;

  • sieving (mesh size of the order of 1 mm) ;

  • micro-screening (mesh voids of the order of ten micrometers);

  • grit removal ;

  • ...