What is the preferred filter size for removing certain pathogens?

The preferred filter size for removing certain pathogens, especially bacteria, is generally one micron. Filters that are one micron in size can effectively capture a range of pathogenic organisms, including many bacteria that can cause waterborne diseases. This size is small enough to block the majority of harmful pathogens while still allowing water to flow through easily.

Filters with larger sizes, such as three microns or six microns, may allow some bacteria to pass through, thus failing to adequately protect against microbial contamination. On the other hand, half a micron filters can be very effective in trapping smaller pathogens, such as some viruses and bacteria, but they can also lead to increased pressure drop and reduced water flow due to their tighter mesh structure. Therefore, the one-micron filter strikes an effective balance for general pathogen removal in most water treatment applications.