For aqueous media such as drinking water, here are some reference charts which compare ranges of relevant pollutants, and suggest different filtration mediums which are relatively effective in removing these contaminants.

Particle sizes using thin film membrane filtration

*NOTE – there is an error in this chart at the very top. Instead of pm which is traditionally for picoMeters, the correct unit should be in um or microMeters. (Microns)

Water Filtration vs Particle Size

Water Filtration Particle Size Chart Common Contaminants