Theory of Declining Rate Filtration. II: Bank Operation

Abstract

In declining rate filtration (DRF), the mode of operation of a bank of filters modifies and determines the performance of an individual rapid sand filter. The theoretical formulation previously developed by the writer for continuous DRF is extended to the case of bank‐operated DRF. The problem is expressed as a system of first‐order nonlinear differential equations for the dimensionless filtrate volumes produced by various filters in the bank. Variable DRF mode of operation is considered explicity in this formulation. The theoretical model permits a study of the evolution of water equality, head loss, and filtration rate of each filter in the bank.