Synthesis and Application of Starch Modified Flocculant

Starch (St) and acrylamide (AM) copolymers was prepared by aqueous solution polymerization, which as raw material finished hydroxyl methylation reaction, then condensation dehydration with dicyanodiamine, cationic starch graft flocculant is synthetized. Hydroxyl methylation reaction optimum conditions are: temperature T=50°C; pH=10; n (HCHO) : n (St-AM)=1.1:1; reaction time t=2h; Dehydration optimum reaction conditions: mole ratio of 1:1; pH = 4; t=3 h; temperature T=45°C. Intrinsic viscosity number of product is 1023 ml/g, cationizing degree is 50%. Treatment performance for oil wastewater is investigated by using cationic starch graft flocculant compound with the inorganic polymeric coagulant polyferric chloride, the experimental results show that: in wastewater pH=7, the amount of inorganic polymeric coagulant polyferric chloride is 2000 mg/L, the amount of starch graft flocculant is 500 mg/L, the treatment effect is the best, oil content and suspension content are less than 10 mg/L, which reach Daqing oilfield re-injection standard.