Research On Flocculation Process Enhanced In Water Treatment And Particle Morphology Control Technology

In conventional water treatment process，coagulation is the indispensable basis unit，which can importantly affect the operation of the water plant and the final effect ofwater treatment, and coagulation is one of the main branches of research direction forwater treatment. At this stage, experimental study on coagulation process mostly use thejar test, which is different with the coagulation process in the actual water treatmentprocess, only suitable for theoretical research and analysis. While the model test cansimulate and reflect the coagulation process in the actual water treatment process better.In the operation of actual water treatment process, the flocculation effect is concernedmostly, and there are few researches on the internal variation of flocculation process.Model test study on the internal variation of flocculation process with different testconditions can guide the practical operation better and optimize the control.In the thesis, pilot model test simulate dynamic change of flocculation process inthe machinery flocculating tank, to dynamic analysis and optimal control the process. Inthe test, polymeric aluminum chloride is used for flocculant, and on-line turbidimeter，particle counter and electronic camera are applied to monitor, monitoring indicatorssuch as turbidity, particle counts, and derivation of indicators such as particle sizedistribution, fractal dimension, average diameter are regarded as a foundation ofanalysis. The variation of flocculation process and the effect of different experimentcondition to the flocculation process can be takenFor simulating actual water treatment and optimize the control, the conventionalprocess parameters and the situation of shock-load, aimed at the water plant operation,were researched and analyzed. Breakage and regrowth technology were used to enhancethe flocculation process. Research finding that simulation test under the condition ofconventional process had the optimum flocculation effect with polymeric aluminumchloride dosing amount30mg/L, and the hydraulic agitation conditions250r/min in thefirst flocculation basin,150r/min in the second flocculation basin,90r/min in the thirdflocculation basin was optimal. During flocculation continuous process, the particlemorphology of more than7microns can be used to measure the effect of flocculation,the more the better the results. The particle morphology for the process between the firstflocculation basin and the second flocculation basin was under effective control, anobvious effect for removing turbidity and particles can be taken. Under the situation ofshock-load, the machinery flocculating tank has a stronger capacity of shock-load.Under the conventional process, for low temperature and low turbidity water, thetreatment effect can not reach the ideal requirements. Comprehensive analysis found that granularity fractal dimension and geometric fractal dimension can complement eachother, the values of them are larger in a good flocculation process.In the study on breakage enhance the coagulation process of low temperature andlow turbidity water, comprehensive analysis found that there will be a betterflocculation effect if primary breakage was taken in flocculation continuous process.The flocs after breakage and restructure were smaller and more compact. To comparewith the primary breakage, the secondary breakage affected the continuous flocculationprocess greater and the effluent water better, and the flocs of secondary breakage afterbreakage and restructure was smaller and more compact than the flocs of primarybreakage. The effluent water quality of the secondary breakage was more stable than theeffluent water quality of the primary breakage. The effluent water quality of the primarybreakage was more stable than the conventional process.