Study On Graft Copolymerization Of Chitosan And Flocculating Ability Of Product

The graft copolymerization of AM or AA or both AM and DMDAAC onto chitosan was mainly studied in this paper. Under the individual optimum conditions, the flocculating abilities of the products were also compared.Through experimental studies, the effect rules of experimental factors of the copolymerization on the products and their flocculating abilities were studied, including reaction temperature, category and concentration of the initiator, viscosity and degree of deacetylation of chitosan and so on.The flocculating abilities of the three different copolymerization products and other commonly used flocculants were studied by using kaolin suspension as the flocculating object. The results indicate that the flocculating activity of every chitosan graft copolymerization product is superior to chitosan. Under the conditions of pH 6.03, the flocculating rate of cationic copolymerization product is up to 94.0% as much as PAM-C. However, the dosage of the flocculant is 2.5mg/L, which is less than PAM-C.The results of dewatering experiments on the sludge from northeastern pharmacy factory indicate that the cationic copolymerization product is the best of the three different copolymerization products in sludge dewatering. The filtrating volume of cationic chitosan copolymerization achieves 70mL, when the pH of sludge 6.00, total sludge volume 100mL, dosage of flocculant 20mg/L, vacuum degree 0.05MPa, filtration time 1min are decided. The sludge water content can be reduced from95.4% to 86.4% after filtrated five minutes. Its dewaterting performance is better than other common flocculants.