A Study On Sedimentation Law Of Yellow River High Turbidity Water

In this thesis the spontaneous flocculation phenomena and its law is studied. Using the dyeing method, the surface area of Xi'an loess particles is firstly determined; the result is clay particles have a huge specific surface area. The silt particles shape and its floccules configuration is observed by TEM and SEM. The molecular-weight of Organic macromolecule flocculating agent is measured by viscometric method. And the forming theory of the pulp-supernatant interface is discussed. The critical concentration and critical particle surface area in constant rate section is studied. The floc density pa and the floc equivalent diameter da are calculated on the basis of experimental data and theoretic analysis. And in this paper the author also discusses the influence of settling column with different size to sedimentation. Through discussing the law of compression regime, the experiential equation about the Roberts coefficient k is firstly put forward, at the same time the reliability of experiential Roberts's equation is validated by contrasting it to practical settling curves. The studies on flocculation parameters of high turbidity water are completed more integrally, including establishing the equation about the relationship between the covering ratio of flocculent on silt surface 6 and the surface area of silt particles S. The re-concentration law of thickener underflow is studies. At the end of this thesis, the semi-academic Roberts's equation is given for calculating thickener depth; this equation shows a newer, reliable ways for designing settling tank and thickener in high turbidity water treatment.