Synthesis Of Microspherical Cationic Polyacrylamide And Its Application In Wastewater Treatment

With an economic boom in China,there is a growing demand for polymer polyacrylamide and its derivatives in water treatment,paper making,oil recovery and other industries,and accordingly its preparation technology has undergone development and improvement.Up to now,there are many methods for the preparation of polyacrylamide in laboratories.This thesis adopts the inverse suspension polymerization to study the synthesis conditions of microsphere polyacrylamide,on the basis of which the cationic polyacrylamide microspheres are prepared.The effects of different monomers,initiators,pH,oil-water ratio and dispersant on the properties of polymers are explored,and the factors which effect the turbidity and chromaticity of self-made P(AM-DAC)in the treatment of simulated sewage are investigated,such as stirring rate,pH,stirring time,the amount of P(AM-DAC)and so on.The conclusions are obtained:(1)Different ionic polyacrylamide microsphere flocculants are prepared by the inverse suspension polymerization,by means of using acrylamide(AM)to react with the three ionic monomer,i.e.acryloyloxyethyltrimethyl ammonium chloride(DAC),methacryloyloxyethyltrimethyl ammonium chloride(DMC)and 2-Acrylamide-2-methylpropanesulfonic acid(AMPS).(2)Synthesis conditions of cationic polyacrylamide microspheres P(AM-DAC)are as follows: the amount of dispersant is 3% Span60-Span80(1:1),the amount of initiator AIBA is 0.2%,and the monomer mass ratio is AM:DAC=3:1,the oil-water volume ratio is 1.5:1,the bath temperature is 75 ?,the reaction time is 3h,the synthesis of cationic degree is 20%,the dispersion is good,the microsphere size is uniform,the particle diameter is about 1mm,the dissolution time is about 70 min millimeter polyacrylamide microspheres.The polymer is identified by infrared spectrometer as P(AM-DAC).The thermal weight analyzer TGA analysis shows that the polymer is stable at room temperature.(3)The factors on efficiency of methylene blue simulated sewage chromaticity removal are discussed in the experiment,such as the amount of P(AM-DAC),bentonite content,pH,stirring time,settling time and stirring rate.The optimum treatment conditions are as follows: the content of bentonite 120mg/L,pH is about 6.0,the stirring time 15 min,PAM 1.2ml,the stirring rate 150 rpm,the settling time 15 min,and the rate of chromaticity removal can reach about 95% in such condition.(4)The effects of the amount of P(AM-DAC),pH,stirring time,stirring rate and settling time on the turbidity removal of bentonite simulated sewage are investigated in experiments.The final optimum treatment conditions are: the stirring rate 150 rpm,PAM 1.2mL,pH is about 6.0,the stirring time 15 min,the settling time 10 min,the final turbidity removal rate can reach about 60%.