filter out
phrasal verbfilter something  out 
- to remove something that you do not want from a liquid, light, etc. by using a special device or substance
- to filter out dust particles/light/impurities
 - The air was improving as the recyclers filtered out the smoke.
 
 - to remove somebody/something that you do not want from a large number of people or things using a special system, device, etc.
- The test is used to filter out candidates who may be unsuitable.
 - The software filters out internet sites whose content is not suitable for children.