ABSTRACT
Filter powders are largely used in the food industry, but their use in the treatment of drinking water is still limited. One of the reasons, therefore, is that they are more appropriate for limited flows smaller than what is required for the supply of potable water. The filtration method as used is a consequence of World War II, during which diatomite or diatomaceous earth was used to filtrate water for the troops. It has been applied successfully for the purification of water in swimming pools, in which only a part of the water is treated and where a temporary failure of the filtration system is sometimes accepted. This is completely opposite to the reliability required for the purification of potable water. We should also mention that in building installations for filtration with powders, certain valuable principles are not always applied. The recommendations for good design are treated in Section 5. At present, a thousand installations for the treatment of potable water using this method exist in the United States.
