在铝盐、铁盐等众多常规的无机絮凝剂中， 阳离子型双氰胺甲醛 (DDF)

Among the many conventional inorganic flocculants such as aluminum salt and iron salt, cationic dicyandiamide formaldehyde (DDF) polymer flocculant has attracted attention because of its positive charge and good removal effect on anionic dyes in wastewater. However, its molecular weight is small, the flocs formed are small and dispersed, and it is not easy to separate and remove quickly from the water. Therefore, researchers often use ethylenediamine, polycyanamide, polyaluminum chloride, urea, ammonium chloride, ammonium sulfate, and polyacrylonitrile fibers to modify DDF. The modified DDF has a significant decolorization rate for dye wastewater. However, the wastewater with high chromaticity cannot be effectively improved, and the pH range is narrow. This is a huge challenge for the effective treatment of anionic dye wastewater with large changes in pH. At present, there are few reports on the use of adsorbent materials to modify DDF to make new adsorbents.

Among many conventional inorganic flocculants such as aluminum salt and iron salt, cationic dicyandiamide formaldehyde (DDF) polymer flocculant has attracted much attention because it has a good removal effect on anionic dyes in wastewater due to its positive charge. However, its molecular weight is small, the floc formed is small and dispersed, and it is not easy to be quickly separated and removed from water. Therefore, researchers mostly use ethylenediamine, cyanamide, polyaluminium chloride, urea, ammonium chloride, ammonium sulfate and polyacrylonitrile fiber to modify DDF. Although the decolorization rate of dye wastewater is greatly improved, it can not be effectively improved for wastewater with high chromaticity, and the pH application range is narrow, This is a great challenge for the effective treatment of anionic dye wastewater with large pH change. At present, there are few reports on using adsorbents to modify DDF to make new adsorbents.

Among many conventional inorganic flocculants, such as aluminum salt and iron salt, cationic dicyandiamide formaldehyde (DDF) polymer flocculant has attracted much attention because of its positive charge and good removal effect on anionic dyes in wastewater. However, its molecular weight is small, the flocs formed are small and dispersed, and it is not easy to be quickly separated and removed from water. Therefore, researchers mostly use ethylenediamine, melamine, polyaluminium chloride, urea, ammonium chloride, ammonium sulfate and polyacrylonitrile fiber to modify DDF. Although the decolorization rate of dye wastewater by modified DDF is greatly improved, it can't be effectively improved for wastewater with high chroma, and the pH application range is narrow, which is a huge challenge to effectively treat anionic dye wastewater with large pH change. At present, there are few reports about using adsorption materials to modify DDF to make new adsorbents.