Research On Flocculation Monitoring Indexes Base On Fractal Dimension

The flocculation has a very important role in water treatment process,and the extent of perfect of flocculation process directly affect the treatment effect of the following treatment. Traditional flocculation theory was based on the hypothesis that colloid was spherical in water, but in fact the characteristic of shape of colloid and Floc. in water has a great influence on the flocculation effect. So study of the effect of shape characteristic of Floc. On flocculation process will help to know the flocculation process more accurately.In the paper, the fractal theory was introduced to flocculation process, and quantitative research of flocculation morphology was done using Fractal dimension. Detailed works and major conclusions were as follows:(1) With respect to the variation in raw water different physico-chemical condition and hydraulic condition in coagulation process investigating was made on the relations between fractal dimension and setter water turbidity , The results showed :â‘ the fractal dimension of floc on the high side and the turbidity of treated water were low when PAC was optimal ,while the fractal dimension was on the low side and the turbidity of treated water was high when PAC were lack or excessive;â‘¡and the fractal dimension and turbidity of treated water changed according to the change of velocity and time of stirring. The fractal dimension was the highest and the turbidity of treated water was the lowest under the quick rapid srirring velocity or longer slow stirring time. The results suggested that the fractal dimension could fully reflect the impact of change of coagulation condition on the coagulation effect, and there was strong relativity between fractal dimension of flocs and the turbidity of treated water. The change of fractal dimension of floc sufficiently reflected the impact of hydraulic condition and physico-chemical condition on flocculation process;(2) The influences of related factors on the fractal dimension of flocs were studied using pilot-plant equipments. The results showed that the fractal dimension was sensitive to the change of influencing factors, the fractal dimension could synthetically represent the overall effect of all the influencing factors on the flocculation process, and it was feasible to use fractal dimension to describe the effect of flocculation.(3) The feasibility of using fractal dimension as checking index in producing experiment was studied. The results suggested that fractal dimension of flocs was more...