Influence of pollutants on rheological characteristics of sediment flow

<p>Abstract: In view of the weak research on the rheological characteristics involved in the variation of the fluid movement caused by the storm runoff carrying a large amount of pollutants and sediments, this study uses the NDJ-5S rotary viscometer and the self-made slim tube viscometer of Northwest Agriculture and Forestry University. On the basis of the research, the influence of pollutants on the rheological characteristics of high-concentration sandy water flow is studied. The results show that the NDJ-5S rotary viscometer can be used well under the sand content of less than 300kg/m<sup>3</sup>. The double vertical tube slim tube viscometer made by Northwest A&F University can better simulate the sand content of 0～800kg/m<sup>3</sup>; The structure of flocculation between particles in sandy water flow will affect the viscosity of muddy water, and the concentration of sediment and other pollutants will have a certain impact on flocculation. Under the same conditions, the concentration of pollutants increases (0～440kg/m3), the viscosity coefficient of fluid increases (90%～114%), and the variation of sand content from Newtonian body to Bingham body is about 300～400kg/m<sup>3</sup>, The influence of pollutants on the variation points of rheological properties is not significant.</p><p>Keywords: pollutants; sediment; variation; viscometer; Newtonian fluid; Bingham fluid</p><p>Funding: This study was funded by the National Natural Science Foundation of China (No. 41877078, 41371276), Key research and development project of Shaanxi Province (2020ZDLSF06-03-01), National Key Research and Development Program of China (No. 2017YFC0504703) and Knowledge Innovation Program of the Chinese Academy of Sciences (No. A315021615). </p>