The purposes of this study are to investigate the settling phenomenon of cohesive fine particles and to predict the concentration of suspended solids in quiescent seawater. Experiments on the settling of cohesive fine particles (Kaoline) in quiescent seawater were performed. The mass balance equation for the growth of cohesive fine particles by settling in quiescent seawater was computed numerically by the Monte Carlo method. Assuming the similarity of the particle size distribution, a simplified method for the prediction of the concentration of suspended solids has been developed. A factor of both collision and adhesion, an important parameter with regard to the growth of cohesive fine particles, was studied by comparing the results of the experiments and computation. The numerically computed results show good agreement with experimental results. The factor depends on particle diameter. It is shown that fine particles in quiescent seawater are less cohesive. The simplified method is also applicable to predict the concentration of suspended solids by considering the decrease in the factor due to the growth of cohesive particles.
