This volume has been written as an introductory reference and working guide to the subject of liquid filtration engineering. The book is designed to acquaint the newcomer to industry practices, and general design and operating methodology for filtration processes. Emphasis is given to pollution control applications, however the technologies and equipment described herein are equally applicable to product recovery and product purification applications. The information presented in this volume is based largely on the author`s collected notes and lectures over the past 15 years. The volume is not intended for researches or equipment developers, but rather for process engineers, plant engineers, and technicians who require basic knowledge of this important unit operation. Much of the design methodology and working equations presented have been tested on pilot plant studies and applied to commercial and semi-commercial operations with success, however, neither the author nor publisher provideten or implied endorsements that these procedures will work in any or all cases. As with any piece of equipment or process, the designer must consult with specific vendors, suppliers and manufacturers, and further, should field test or at a minimum, conduct pilot tests to ensure performance in the intended application. Filtration equipment, operation conditions, and the use of filtration aids are highly dependent upon the properties of the suspension being filtered. Furthermore, overall process constraints and economics can have major impacts on the selection of equipment, their operating modes and characteristics, and efficiency. The author wishes to extend a heartfelt gratitude to Butterworth - Heinemann for their fine production of this volume, and to members of the United States Environmental Protection Agency for their advise and consultation on some of the materials presented herein.