The Scientific Basis of Filtration

K.J. Ives Professor of Public Health Engineering University College London The filtration of liquids is a process which is widely used in industry. In some cases the object of the process is to clarify the liquid, as in the filtration of beer, or sugar solutions; in other cases the object is to recover solids suspended in the liquid, for example, ores in mineral processing, or the production of pigments such as titanium dioxide. In addition to the many industrial applications of liquid filtration, a considerable investment lies in municipal applications for the filtration of drinking water, wastewater and the sludges arising from water and sewage treatment. Indeed, in terms of volume filtered, it is likely that the municipal application exceeds that of industry. The difference between clarification of the liquid and recovery of the solids is often expressed in the division of the processes into deep bed filtration and cake filtration.