Aquaculture Engineering (2+1)

Filtration - Classification according to form of materials

Unit 12 - Management of ponds

Filtration

Classification according to form of materials

Filtration system are classified into following groups according to the form of materials they handle

• Liquid–Liquid systems
• Liquid–solid systems
• Liquid–gas systems
• Gas–solid systems
• Gas–gas systems
• Solid–solid systems
• Solid–liquid–gas systems

Thus a liquid–liquid system is one in which filtration is used to separate two or more liquids, where as in a liquid–gas system separation of a liquid and a gas is desired. Although there are seven groups, filtration in aquatic cultural systems usually falls into 1, 2, 3 or 7 groups with the first two groups being the most common. Filtration is accomplished by identifying properties of the materials to be separated, then using the differences in properties to devise a separation procedure. Material properties often useful in filtration are listed below.

• Density
• Particle size
• Electrical properties
• Chemical properties
• Magnetic properties

Filters are classified as mechanical, gravitational, chemical or biological.