Preparation Of Starch-acrylamide Graft-type Flocculant By ⁶⁰Coγ Ray Irradiation

For the last few years. Grafting derivations with cation group will become widely used in the future because it possesses the properties of the starch-grafting-polyacrylamide and the preparation for cationic starch by semi-dry state process, thesis focuses on the research of cationic starch with vinyl group.Gelatinous starch was mixed with acrylamide to crank out water solusion. 60Coγ-ray mutual radiation induced graft copolymerization of corn starch with acrylamide,and work out grafting yield. And the use of two methods of its cation, the impact of reaction conditions on the various factors studied. Finally, we applied these cationic starch-acrymide inarch- copolymerization as flocculant on treating activated sludge . pH value of the starch grafted cationic flocculant has little effect on flocculation.Qualitative analysis of its structure.Wave number of 1668 cm-1absorption peak was amide-based copolymers of the characteristic absorption peak .Wave number of 1546ccm-1 in the vicinity of the strong absorption peak that is Mr amide-CO-NH- deformation vibration absorption peak.Analysis confirmed :starch graft copolymer of acrylamide modified by cation existence of molecules-CO-NH-CH2-N(CH3)2.From electron micrographs can be seen the surface of starch graft copolymer and cation of the starch graft copolymer is an uneven, multi-hairy and curly loose shape was closely embedded in the overall state of the granular structure.Starch, we can see a combination of a large number of branched-chain acrylamide On the adsorption capacity of suspended solids, have greatly enhanced .Through the single factor experiment, factors that had influenced on the grafting yield were mainly considered, including absorbed does , reaction temperature, the mass ratio about acrylamide and starch .On the basis of the experiments, the three factors and three levels orthogonal experiment was used to search the optimum grafting yield parameters, the optimum conditions were:absorbed dose was 10kGy, reaction temperature was 30℃, m(acrylamide):m(starch)=2:1.Cation using irradiation method of response.Through the single factor experiment, factors that had influenced on the cationic degree were mainly considered, including Etherification agent , NaOH , water.On the basis of the experiments, the three factors and three levels orthogonal experiment was used to search the optimum cationic degree parameters, account of the cost factors the optimum conditions were: the dosage of etherification agent was 30g , the dosage of NaOH was 0.3g, the amount of water was 30ml.Compare the effect of flocculant used in the experiment. on flocculation.pH value of the starch grafted cationic flocculant has little effect on flocculation. However, have larger impact of polyacrylamide-type flocculants . Chloride-type flocculant charge more for good performance when the flocculation amount is larger. Flocculant Starch Graft dosage for the best for 450mg/L,Polyacrylamide and chloride is the best dosage 600mg/L.