Research On Interactional Relationship Of Growing Floc Within The Best Area Of The Turbidity Of Water

In the process of water supply treatment, the effect of flocculation has direct influence on the treatment result of the succeeding technology units,water quality and the cost of the treatment.,so it becomes the key point of environmental research field.In 2006, Ministry of Construction promulgated the new《Standars for drinking water quality》(GB5749-2006), in which the national standard requirements on water quality has been increased from 35 items to 103 items with stricter regulations. Especially, the national standard turbidity has been adjusted from 3 degree to 1 degree. In order to reach this new national standard, most of the water factory have increased the amount of flocculant so as to reduced the turbidity of the settled water and finally enable it to be within the best area of the turbidity of the water. However, people do little researche on the changing characteristics of flocs formation and its influencing factors within the best area of the turbidity of the water.Only adding the amount of flocculant sometimes can not reduce the turbidity of settled water, on the contrary, it might has some negative impact on the effect of flocculation, resulting in further deterioration of the water quality.This thesis, taking aluminum sulfate as flocculant and particles of gaolintu in the water as the wipe off target, makes an online test and analysis on changing process of the dynamic flocculation form of aluminum salt by SCD and on-line TV-microscope base on the decided water condition. The result of the experimental research indicates: the change ofξpotentials of colloid surface leads to the change of flocs formation in the flocculation process, and the change of flocs formation is the main factor that influences the the effect of flocculation. For different turbidity water,streaming current,sum of particles and the fractal dimensions can make an effective and accurate evaluation of the flocculation effect. when it is within low turbidity water, comparing with turbidity of settled water, streaming current,sum of particles and the fractal dimensions can reflect the changing of flocculation effect more accurately. In addition, this research also studies the fractal dimensions through picturing and compute fractal dimensions with many different calculation methods. Through comparison, it is found that the way of acreage-perimeter can accurately compute fractal dimensions of flocs. In this thesis, the concept of best area of the turbidity of the water is put forward for the first time, and the experiments also prove the existence of it. The research indicates that streaming current,sum of particles and the fractal dimensions changes with the change of amount of flocculant , and in this process, index of flocculation appears to fluctuate to different extent within certain range. Outside this range, the change of index of flocculation shows obvious rules in accordance with different amount of flocculant, we define this range as best area of the turbidity of the water...