Wastewater treatment is usually characterized as consisting of four sequential processes: preliminary, primary, secondary and tertiary treatment. This publication will introduce you to processes and equipment for primary treatment of wastewater. You will be introduced to descriptions, functions and design considerations for sedimentation tanks and clarifiers, chemical precipitation, and Imhoff tanks. You will learn how the primary treatment processes works together with the preliminary, secondary, tertiary and sludge handling processes to form a complete wastewater treatment plant.