Control Techniques for Coagulation‐Filtration

When the removal of suspended solids from unsoftened surface waters is the primary objective of treatment, coagulation is all‐important. The efficiency of the plant and the quality of the treated water depend upon careful control of the process. Type and frequency of tests for controlling coagulation depend largely upon the character of the raw water and the plant design. Some parameters may be evaluated in the laboratory, while others need monitoring of the treatment equipment or the treated water at various stages of treatment. Every operator develops his favorite monitoring and control techniques that allow him to produce a satisfactory product most of the time. This article compares some of these techniques and evaluates their general applications for research and plant control.