is one of the process of separation and it defined as the action or process of filtering something. The act or process of filtering, especially the process of passing a liquid or gas, such as air, through a filter in order to remove solid particles. In liquid filtration Journals, such as that applied in waste material treatment, a liquid can be pulled through the filter by attraction, as in the examples given. On the opposite hand, some sort of applied pressure, or a pressure differential created by the existence of a vacuum, can force the liquid through the filter. Gas filtration is employed in a common appliance, the vacuum cleaner, which passes a stream of dust-filled air through a filtering bag inside the machine. The bag traps solid particles, while allowing clean air to pass back out into the room. This is essentially the same principle applied in air filters and even air conditioning and heating systems, which, in addition to regulating temperature, also remove dust, pollen, and other impurities from the air.