Comparison of a native clay soil and an engineered clay used in experimental ceramic pot filter fabrication

Ceramic pot filters (CPFs) have been shown to be an effective means of household water treatment in the developing world. The filters are typically made using local labor and locally available materials including clay soils and various burn out materials used to create porosity. Artisanal approaches may be used to manufacture the filters, and there have been efforts to improve CPF performance through laboratory studies. The importation of soil to make the filters may be highly regulated and could be cost prohibitive, so some researchers use commercially available clay to fabricate experimental filters. However, such efforts typically do not include a comparison of the engineered clay to native clay soil, nor do most studies compare the performance of experimental CPFs fabricated from engineered clay to CPFs made from native clay. This study compares mineralogical and geotechnical properties of a clay soil from Rabinal, Guatemala, used to produce CPFs in that country to an engineered clay developed for use in laboratory experiments. Flowrate is the primary quality control parameter used in CPF production, and performance testing indicated that experimental CPF flowrates were not necessarily a function of clay composition. However, engineered clay could be used as a surrogate for native soil with some limitations.