聚二甲基二烯丙基氯化铵对聚合硫酸铁处理冬季长江水的助凝效果

Coagulation aid effect of PDM in treatment of winter yangtze river water combined with PFS

采用聚二甲基二烯丙基氯化铵(PDM)与聚合硫酸铁(PFS)复合制得的稳定型复合混凝剂,用于冬季低温长江水强化混凝脱浊处理。通过混凝烧杯试验,考察了PDM对PFS在脱浊效果和沉淀性能上的改进程度。结果表明:对温度为5～7℃,浊度为45 NTU左右的冬季长江水,PDM助凝效果明显,同时PFS与PDM的复配比例越低,复合混凝剂混凝脱浊效果越好。复合混凝剂中PFS的用量比单独使用PFS时的少。复合混凝剂能增大絮团的沉淀速度,克服冬季低温条件下单独使用PFS时絮体轻而细小、沉淀慢、破碎现象严重的问题,从而使沉淀出水水质能够迅速稳定地达标,同时,还可明显改善PFS处理时出水带色、腐蚀设备等问题。

A steady composite coagulant prepared by polydimethyldially ammonium chloride （PDM） and polyferric sulfate （PFS） was used for turbidity removal of yangtze reiver water in winter. Through the jar test on the coagulation, the improving effect of PDM on turbidity removal and sedimentation property of PFS was investigated. The results showed that： for the yangtze river water in winter with temperature of 5 - 7℃ and turbidity of 45 NTU, the coagulation aid effect of PDM was obvious, furthermore, the lower the compound ratio of PFS and PDM was, the better the turbidity removal performance of the composite coagulant would be. The PFS demand for the composite coagulant was less than the demand when it was used singly. The composite coagulant could increase the settling velocity of flocs, the problems that appeared when PFS was used singly such as： the flocs was light and thin, the sedimentation was slow and the fragmentation was serious could be solved, then the effluent quality after the sedimentation could achieve the standard rapidly and steadily, meanwhile, the situation of effluent turbidity and corrosion of equipment which appeared during the treatment by PFS could be remarkably improved by PDM.