A Lamella Clarifier is used to separate organic and inorganic solids from liquid. The solid material, which is denser than the liquid, falls under the influence of gravity to the base of the tank,
which is often sloping or conical, from where it is pumped away as a sludge. Some solid materials may not settle easily, or may take too long to settle under the influence of gravity alone.
Coagulants and flocculants, such as polyelectrolytes, ferric sulphate or lime, may be added to enhance the agglomeration of particles, and speed up settlement.