Filtration is a physical separation process in which the particles in suspension are retained using a filter. The filters are highly efficient and safe in the solid-liquid separation process (Pires et al., 2012). The filtration is a separation method that is suitable for large microalgae

such as Spirulina but unsatisfactory for smaller cells such as Chlorella and Scenedesmus (Ho et al., 2011).

Filtration provides easy operation and construction, low investment, and insignificant abrasion. The filters can be operated under pressure or vacuum (Harun et al., 2010). The main limitation of filtration is the reduction of the permeation flow during the process; this is due to adsorption and concentration of the compounds on the membrane surface (Rossi et al., 2008).