Index >> Microbes and Hydrosphere>>Purification of Water on a Small Scale Filtration

In the Katadyn filter, the surface of the filter is coated with a silver catalyst so that bacteria coming in contact with the surface are killed by the 'oligodynamic' action of the silver ions, which are liberated into the water.

Filter candles of the fine type usually remove bacteria found in drinking water, but not the filter-passing viruses. Filter candles are liable to be logged with impurities and bacteria. They should be cleaned by scrubbing with a hard brush under running water and boiled at least once a week.