Cryptosporidium in potable water - filtration

Sedimentation – because of small size and low density the settling rate of oocysts is extremely low and removal by sedimentation is insignificant. flocculation - clumping with -ve charged particles. rapid filtration - successful after flocculation. slow sand filtration - the top few centimetres support aerobic bacteria that produce a network of extracellular polymers forming a natural biological filter. membrane filtration - final finishing process.