基于Zeta电位及微观形态的极细石英质粉砂絮凝特性研究OA

The flocculation of fine-grained sediment significantly influences their transport behavior and coastal evolution,making it essential to understand their flocculation characteristics and underlying mechanisms.In this study,ultrafine quartz silt was selected as a representative non-clay mineral,with kaolinite serving as a typical clay mineral for comparison.The flocculation behavior of quartz silt particles was investigated by analy-zing the grain size distribution,microscopic morphology,and Zeta potential variations of both samples in NaCl and CaCl2 solutions with varying concentrations.Results indicate that ultrafine quartz silt can flocculate in freshwater,primarily through the aggregation of fine particles.As electrolyte concentration increases,the Zeta potentials of both minerals exhibit an initial sharp increase followed by fluctuations around a stable value.However,the fluctuation centers and amplitudes differ between the two samples.The trend of floc Zeta poten-tial and gradation parameters of non-clay mineral components of particle size less than 8 μm with variation of e-lectrolyte concentration are similar to those of clay minerals.It is suggested that cohesive sediment theory can be applied to estimate floc size and settling velocity for non-clay particles smaller than 8 μm.