基于絮凝体分形控制的絮凝动力学指标研究

针对目前絮凝工艺的动力学控制指标和絮凝体形态学研究的不足,基于分形理论,应用分形维数描述絮凝体的形成和成长,进行了絮凝动力学指标的研究.利用数学分析方法,推求絮凝体的密度和强度的表达式,得出絮凝体的密度和强度是分形维数的函数,同时絮凝体的强度与水体的能耗成反比.通过量纲分析方法,得出絮凝体分形维数是能耗GT与剪切强度Fr的函数,进而确立絮凝动力学控制指标为G、GT和Fr,以期为工艺设计和运行提供了科学依据,为实际工程应用提供了合理的指导.通过形态学和动力学两方面的研究表明,高效的絮凝过程需要控制一定的G、GT和Fr的递减梯度,并保证絮凝体达到一定的分形维数Df.

Research on flocculation kinetics factors based on control of floc fractal dimension

The current study on flocculation kinetics control factors and floc morphology has several shortages.In this paper,fractal dimension was used to describe the formation and growth of flocs on the basis of fractal theory,and the research on flocculation kinetics factors was carried out.According to mathematical analysis of floc density and floc strength expressions,it was verified that floc density and floc strength was the function of fractal dimension,and floc strength was inversely proportional to energy consumption.Based on the dimensional analysis method,it was found that fractal dimension was the function of the energy consumption GT and the shear strength Fr.Furthermore,the flocculation kinetics control factors defined as G,GT and Fr were proposed which were hoped to contribute scientific basis for the design and operation of coagulation processes and reasonable guidance for practical engineering application.Morphology and kinetics researches on the flocculation process showed that,in an efficient flocculation process certain descending gradient of G,GT and Fr should be controlled,and fractal dimension Df of flocs should be guaranteed to reach a certain value.