Olá Teresa,

Aqui tem alguma informação, que lhe pode vir a ser útil. Tudo de bom, para si!

Floc is flake of precipitate that comes out of solution during the process of flocculation.
Flocculation refers to a process where a solute comes out of solution in the form of floc or "flakes." The term is also used to refer to the process by which fine particulates are caused to clump together into floc. The floc may then float to the top of the liquid, settle to the bottom of the liquid, or can be readily filtered from the liquid. In ...flocculation.

http://www.glossary.com/reference.php?q=Floc