Hindered settling of mud flocs: Theory and validation

This paper deals with settling of highly concentrated cohesive sediment suspensions. We evaluate a new hindered settling formula. New settling experiments on these highly concentrated suspensions are described to test this formula. For the analysis of the experiments both an analytical and a numerical method are used. Kynch's analytical theory, based on the method of characteristics is used to study the type of settling. Furthermore, a 1DV-point model is used for analysis of the settling process. We have implemented the new hindered settling formula in this model, which is tested against experimental data. It is concluded that the data are described fairly well. The analysis with the theory of Kynch [1952. A theory of sedimentation. Transactions of the Faraday Scociety 48, 166–176] and the model show that highly concentrated suspensions can settle with either one interface or with two interfaces, depending on the initial concentration and the shape of the settling flux function.