Preparation And Flocculating Performance Of Inverse Emulsion Of AM/DAC

The cationic polyacrylamide (CPAM) was synthesized by inverse emulsion polymerization using acrylamide (AM) and acryloyloxyethyltrimethyl ammonium chloride (DAC) as monomers, Span80-Tween80 as compound emulsifier, liquid paraffin as continuous phase. The influences factors to the viscosity of product and the stability of the system were discussed, such as the volume ratio of oil to water, the ratio and concentration of Span80 to Tween80, the ratio and concentration of AM to DAC, the type and concentration of initiator, the initial reaction temperature, reaction time, inlet time of N2, whisk speed, the drying and granulation. The optimum conditions of copolymerization were obtained as follows:the volume ratio of oil to water was 1:1.6, the emulsifier dosage was 30%, the mass ratio of Span80 to Tween80 was 3:5, the concentration of monomer was 30%, the mol distribution ratio of AM to DAC was 2:3, initiating temperature was 40℃, inlet time of N2 was 30min and reaction time was 5 hours. The cationic polyacrylamide with viscosity 897 mL·g-1 and cationic degree being about 60% was obtained.Using acetone and the ethanol to demulsify the product, then dry it. The optimum conditions of deemulsification and drying were obtained as follows: then at the Vacuum Degree of 1000MPa, the drying temperature was 70℃, drying time was 10h. Using the differential thermal analysis and infrared spectroscopy characterize the self-made CPAM. The infrared spectroscopy result shows that self-made CPAM was consentaneous with the theory. The differential thermal analysis result shows that the self-made CPAM was decomposed at 265.54℃.Use the self-made CPAM to flocculation the sludge in condenses pool of a sewage plant in the city of Chongqing, China. The experiment shows that the performance of self-made CPAM has related with the viscosity of CPAM, the cationic degree, the adding quality of CPAM, the mixing speed, etc. With the viscosity of CPAM was 897 mL·g-1, the dosage was 25mL, cationic degree was 60%, CPAM has the better treatment effects. Under the optimum conditions, the transmittance removal for upper clean liquid was up to 96.9%, filtrate turbidity was decreasing to 11.2, the water content for press cake was decreasing to 62.05%. In addition, the paper also researched the effects of viscosity of CPAM, the dosage and the cationic degree. The result shows that the dosage and the cationic degree have optimum scope. It means sludge dewatering was not better even with excessive cationic degree and dosage. In addition to that, the temperature and mixing speed also have effect to sludge dewatering...