Recently, the flocculants used for dye decolorization are mainly aluminum salts and iron salts. These two types of flocculants have good decolorization effects on water-insoluble dye wastewater, but water-soluble dyes such as target reactive dyes have poor decolorization effects. . The research on Poly(Dimethyl diallyl ammonium Chloride) (PDMDAAC) series of flocculants has gradually deepened, and this series of flocculants are being used more and more widely in the field of water treatment.

PDMDAAC series flocculants are excellent decolorizing agents, which are not only suitable for wastewater containing disperse dyes, but also have good decolorizing effects for wastewater containing reactive dyes that are difficult to treat.

Cationic degree, molecular weight and the structure of the flocculant are important factors that affect the decolorization effect of the PDMDAAC series of flocculants. Generally speaking, the higher the cation, the larger the molecular weight. The better the decolorization effect. For reactive dye wastewater, cationicity has a greater impact on decolorization; for disperse dye wastewater, the impact of molecular weight on decolorization increases. PDMDAAC flocculant containing VTMS has a special decolorization effect due to its special structure.

For reactive dye wastewater, PDMDAAC series flocculants are electro-neutralized, and their quaternary ammonium ions are combined with the anionic groups of dye molecules to make them precipitate out of the water, and then aggregate and settle through adsorption and bridging. For disperse dye wastewater, the absorbance of the dye solution is mainly reduced by adsorption and bridging.

PDMDAAC series flocculant is compounded with PAC. It can complement each other's advantages, so that the decolorization effect is better, the processing cost is lower, and the operation and post-processing are easier. But when compounding, we must pay attention to the ratio of the two and the specific operation details (this needs to be obtained through a lot of experiments), otherwise the decolorization effect will become worse. Therefore, in water treatment, the treatment The object to choose the appropriate PDMDAAC series flocculant. For the flocculant containing VTMS, when introducing VTMS, it should avoid the decrease of its molecular weight and cationicity. When necessary, PDMDAAC series flocculants should be compounded with inorganic coagulants to achieve efficient treatment purposes.