what is filtration

Filtration is a physical separation process that separates solid matter and fluid from a mixture using a filter medium that has a complex structure through which only the fluid can pass. The process involves the use of a filter medium that permits the fluid to pass through but not the solid particles. Filtration can be mechanical, biological, or physical, and it can be used to separate solids from liquids or gases. The basic requirements for filtration include a filter medium, a fluid with suspended solids, a driving force such as a pressure difference to cause fluid to flow, and a mechanical device that holds the filter medium, contains the fluid, and permits the application of force. Filtration is commonly used to purify water for cities and is also used in chemical laboratories. Examples of filtration include slow sand filters, trickling filters, and coffee filters. Filtration is also a biological process where water and solutes move across the cell membrane due to hydrostatic pressure from the cardiovascular system.