The Research On Fractal Structures Of Microbial Flocculants

In the water and wastewater treatment process,the coagulation process which is the key to water-wastewater separation and solid-liquid separation plays a very important role. Flocculant which is a key agent in coagulation process can destroy the stability of the particles in water.At present,there are two major kinds of flocculants:one is nutrients flocculation agentand organic polymer flocculant kind material,including synthetic organic polymer and natural polymer flocculant,These flocculant are widely used in cogulation process,however the insecurity and the problem of secondary pollution during the using process yet impossible to ignore.In nowadays society,accompany with the increase of peoples higer demand for flocculants,to develop high security and no secondary pollution products become a hot spots.Microbial Flocculants belong to this new type of flocculants.In the experiment,the morphological specificcity of flocs of PZ-MBF on kaoline soliquid can be observed by electron microscope,the fractal dimension can also be calculated.According to the result, the fractal dimension of the flocs varied in different reaction condition. By analyzing the researches of fratal characteristic,there is close connection between the effect of flocculation and fratal dimension.It is found that the precipitation effect and the fractal structures of aggregates will be affected by the inventory of MBF,pH value. When the MBF dosage ranged in5-50mL,there is a higher level of flocculation rate and fractal dimension which ranged in85.94%～90.56%,1.507～1.806respectively.Furthermore,a good linear relativity can be sawn between them.It is also can found that,there is a better flocculation effects and fractal features when the raw water in alkaline acidic pH. Meanwhile the pH value of raw water is neutral,the fractal festure of the flocs is not obvious.In addition,through six factors four level of orthogonal experiment, it is also found that the inventory of MBF,pH value of raw water have a significant influence on flocculation effect.