Assessing Perlite as a Sand Substitute in Filtration

Filtration has been used since the beginning of the nineteenth century to remove particulates from water. Granular media filtration is currently the most common filtration process used in water and wastewater treatment. Because of its low cost and ease of operation, quartz sand is the most widely used filter media.1 Other filter bed materials include anthracite, coal, magnetite, garnet sand, and coconut shells. In some areas, such as Turkey, a limited amount of sand suitable for use in filter beds is available, and other filter bed materials, such as those just mentioned, are not available at a reasonable cost. Limited sources of sand, limited availability or high cost of usual alternative materials, and the rapid increase in the number of filtration units being installed in water and wastewater treatment plants in Turkey spurred a search for a substitute for quartz sand.