Similitude Interpretation of Jar Test Data

Abstract

A method for using a modified jar test in conjunction with a hydraulic similitude calculation was developed to predict sedimentation basin performance. The method was tested at the Mark B. Whitaker Water Treatment Plant in Knoxville, Tennessee, for field verification. A comparison of jar test turbidity data collected at settling times controlled by the similitude calculations versus the turbidity of the sedimentation basin effluent was very close to ideal (one‐to‐one relationship). The settling data suggested that a measurement of the floe size distribution might be a more reliable method for coagulant dosage control. Jar test settling time had a significant effect on the selection of the operating dosage. Therefore, if a jar test is used, the sample time must be related to the hydraulic conditions of the treatment plant.