Studies Of The Formation, Aqueous Solution Properties, Flocculating Performance And Mechanism Of OS/PDADMAC Complexes

To utilize plentiful starch resources in our country and meet the high requests on flocculants in modern wastewater processing, oxidized starch/ PDADMAC complexes as flocculants were studied. In chapter 2, the formation of OS/PDADMAC complexes were studied, the complex system presented obvious polyelectrolyte viscosity behavior, the two components interacted mainly via electrostatic force and the complex was whole electrically positive. In chapter 3, the aqueous solution properties of OS/PDADMAC complexes were determined via viscometer, the results showed that, the aqueous solution properties of the complexes made evident changes due to different kinds and different concentrations of inorganic salts. The interaction between the complexes and salts augmented with the ionic radius of salt augmenting, so did the curling extent of macromolecular chains; however, the reduced viscosities and intrinsic viscosities reduced. With the concentrations of salts augmenting, the intrinsic viscosities of complex system decreased, and the Huggins constant k' increased. In chapter 4, the flocculating performance of DJF-2 treating stone wastewater was studied, with the addition of DJF-2 at the dosage of 8mg/L, the main pollution indexes of the wastewater (pH 9) could tally with the National Sewage Discharge Grade-2 Standards after sedimentation for 30 min, and the treatment cost was the lowest of all related flocculants. In chapter 5, the flocculating mechanism of the complexes treating stone wastewater was discussed via TEM, it's concluded that, the adsorption/bridging mechanism was the main, with the electrical neutralization and meshing secondary.