| Cationic polyacrylamide is a widely used water-soluble polymer flocculant. It has anumber of advantages,such as less dosage, low cost to waste water treatment and sludgedewatering, low toxicity, and widely range of pH used. The hydrophobic associationpolyacrylamide has a unique solution hydrodynamic properties due to the introductionof the hydrophobic monomer.Hydrophobic association polyacrylamide can makeintermolecular and intramolecular association in macromolecular chains to form athree-dimensional reversible physical cross-linked structure because of hydrophobiceffect and aggregation. This structure can enhanceinteractions of polymer and smallmolecules in water, and improve flocculation of hydrophobic associationpolyacrylamide.In this research, hydrophobic association polyacrylamide P(AM-DBC) with ionicand hydrophobic groups was synthesized by the monomer of acrylamide(AM) andcationic monomer (N,N-Dimethyl-N-acryloyl oxyethyl-N-benzyl) ammonium chloride(DBC), using photo-initiation polymerization method. The paper considers the factorwhich can affect the performance of P(AM-DBC), such as total monomer massconcentration, molar ratio of monomer, initiator dosage, urea dosage, pHandphotopolymerization time. The polymer was characterized,solution properties andflocculation properties of polymer were studied.After the single factor experimental research, it takes these factors whichthe totalmonomer mass ration is40%, the monomer ratio of9:1, the amount of initiator is0.03wt%, urea amount of1wt%, reaction system pH value is4, for60min asphotopolymerization time, as the P(AM-DBC) optimal conditions for synthesis. Therelative molecular mass of P(AM-DBC) basedon this synthetic condition are between6,680,000and8,280,000and the polymers have good solubility.Determined by infrared spectrum analysis of functional groups, the polymer can besure it is hydrophobic association polyacrylamide P(AM-DBC). By nuclear magneticresonance spectrum analysis, the proton peaks of the two monomers were appeard in thespectra of polymerization product, which once again confirmed that the polymer waspolymerized by AM and DBC.The solution properties of P(AM-DBC) with different content of DBC andmolecular weights were studied. The results showed that P(AM-DBC) has strong thickening properties in aqueous solution.As the copolymer concentration above thecritical association concentration C*, P(AM-DBC) forms supramolecularstructures-dynamic physical cross-linked structure based on intermolecular associationwhich results in the enhancement of hydrodynamic volume and a rapid increase ofappearant viscosity.With the increase of molecular weight and DBC content, theapparent viscosity of the polymer solution is increased, but C*of P(AM-DBC) isdecreased.The preparation of the P(AM-DBC) was used for sludge dewatering experimentalresearch. The experimental data showed that the performance of sludge dewatering isnot better even with bigger relative molecular mass, higher cationic degree and greaterdosage of P(AM-DBC). When the dosage of P(AM-DBC) is45mg/L, the moisturecontent of sludge reaches a minimum of73.77%. P (AM-DBC) is compares with CPAMthat is commonly used in sewage treatment plants,it found that they have goodimprovement effect on sludge dewatering performance, and under the sameexperimental conditions,the sludge which is quenched and tempered by P(AM-DBC)has lower moisture content than the sludge which is quenched and tempered by CPAM,but the optimal dosage of CPAM is less than the optimal dosage of P(AM-DBC).The color removal of dispersion organe was inverstigated by P(AM-DBC). Theresults show that the initial concentration is a factor which impact decolorization of dye,reasonable initial concentration of dye wastewater can achievethe ideal treatment effectunder optimal dosage in reality wastewater treatment. P(AM-DBC) has higherdecolorization efficiency than that of P(AM-DAC) because of the hydrophobecharacteristics of DBC. When DBC content of P(AM-DBC) is15mol%, maximumdecolorization of dispersion organe is88.56%. |
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