Colloidal particles in suspension are excluded from the vicinity of various hydrophilic surfaces. On the basis of this phenomenon, a novel method of water purification is proposed and tested. Proof-of-concept is demonstrated using a custom-made extractor that collected clean water from the annular "exclusion zone" within a Nafion tube. Up to 99.6% of particles could be removed from the suspension. The experimental results suggest that particle exclusion may provide a new framework for water purification from both organic and inorganic matter, as well as from harmful pathogens.