Polyacrylamide-grafted legume starch for wastewater treatment: synthesis and performance comparison

A novel polyamidine-grafted carboxymethylcellulose: Synthesis, characterization and flocculation performance test

This study facilitates the synthesis process of a novel graft copolymer (flocculant) using carboxymethyl cellulose, acrylonitrile and N-vinyl formamide as raw materials. The carboxymethyl cellulose graft polyamidine (CMC-g-PAMD) can be used as new flocculant to replace the traditional polyacrylamide flocculant, which manifested its excellent flocculation and degradation efficiency. A five-membered cyclic copolymer was prepared by the graft copolymerization, and the synthesized flocculants were characterized by EA, TG-DTG, FT-IR, SEM and NMR, confirming the successful synthesis of the desired copolymers. The operation conditions for copolymerization were experimentally investigated, and the results indicated that the optimal initiator dosage, copolymerization temperature, amidinization temperature, acidification time and flocculant dosage were 4 g/L, 50°C, 90°C, 3 h and 60 mg/L, respectively. Compared with the traditional polyacrylamide flocculant, the CMC-g-PAMD presented an outstanding flocculation ability of 96.1% under its optimal operation conditions, which showed an enormous potential in the application of coalmine waste-water treatment.