탁도 측정을 통한 점착성 유사의 플록형성 분석

Flocculation Analysis of Cohesive Sediment by Turbidity Measurement

In many estuaries and rivers, the contaminants such as heavy metals have became serious threat to ecosystem including human communities since eagerly development of heavy industrialization. It was found that such materials tended to bound with cohesive sediments, and this bond mechanism is affected by hydraulic characteristics, for instance, turbulence intensity. To understand the complex relationship with the sediment-bond mechanism and hydrodynamics, the study for flocculation which includes the bond between sediment particles without heavy metals should be preceded as the first step. In this study, the flocculation of single sediment (Kaolin) was analysed through laboratory experiments in which the rotational jar-flow was generated and 3D numerical simulation which was performed to obtain the detailed flow fields and calculate hydraulic characteristics. First, the PIV experiment was conducted for the verification of 3D numerical model. And the flocculation index (IF) was proposed to consider the relation with the external energy and average turbulence length scale through the regression approach. The results showed that the flocculation was more affected by turbulence length (eddy size) than by turbulence intensity, and there was the significant specific range of turbulence length about formation of flocculation.