ABSTRACT
The mechanism of filtration, the comparison of slow sand and rapid sand filters, and the main components of a filter are described in this unit. Under filter operation, the various types of flow control and the criteria for stopping filter run, backwashing and filtering to waste are discussed. Parameters used for design and process control are defined and illustrated by presenting relevant solved example problems. The hydraulics of filter operation and an equation for head loss through a clean filter, and related example problems are also included. A brief description of common problems encountered in the operation of filters follows.
