聚合氯化铁混凝剂的电性及除浊性能研究

采取共聚与复合两种制备工艺 ,加入稳定剂 (S) ,合成了具有不同碱化度 (B)的稳定的高浓度聚合氯化铁混凝剂 (PFC)。通过测定zeta电位对其水解物的电动特性进行了研究 ;通过对模拟悬浊水样的絮凝实验 ,对其除浊性能进行了考察。结果表明 ,在pH >5的范围内 ,PFC比聚合氯化铝 (PAC)的zeta电位有所降低 ,PFC的zeta电位随pH的变化趋势与PAC也有所不同 ;

磁场对混凝-膜过滤工艺中铁盐聚合态的干预机制

为提高氯化铁混凝剂的混凝性能并减少膜污染,以四氧化三铁为磁种,利用剩磁对氯化铁混凝剂聚合态进行调控,并进行混凝-膜过滤实验,分析磁化干预对混凝剂形态分布和处理效果的影响。结果表明:在0.2T的磁干预强度下磁化之后的磁种悬浊液存在剩磁,磁化3min时,剩磁达到最大;水解过程中Fea逐渐转化为Fec,而通过外磁场干预,一定程度上抑制了混凝剂由低聚态向高聚态的转化,且剩磁越大,低聚态含量越多,被磁化3min的磁种影响后70mg/L的氯化铁溶液中Fea+b约占总铁含量的26.3%,比不磁化和磁化9min时分别高出了8.2%和5.7%;在混凝-膜过滤过程中,磁化3min时絮体尺寸最大,约为750μm,膜通量为105L/(m^2·h),远大于直接过滤的膜通量45L/(m^2·h),膜通量下降最慢,反洗之后膜通量恢复到90%以上,恢复程度最佳。。

PAC-PPFC复合混凝预处理酮连氮法制肼废水

为加强混凝预处理酮连氮法制肼废水的处理效果,研发了以聚合氯化铝(PAC)-聚磷氯化铁(PPFC)复合混凝剂,以阴离子型聚丙烯酰胺(APAM)为助凝剂的强化混凝工艺。通过单因素实验和响应曲面设计,探讨了强化混凝工艺预处理酮连氮法制肼废水参数。结果表明,COD和NH^+4-N去除率影响先后顺序为废水pH>PAC-PPFC投加量>APAM投加量和PAC-PPFC投加量>废水pH>APAM投加量,各影响因子之间存在一定的交互作用。当PACPPFC投加量2 g/L、APAM投加量6.3 mg/L、原水pH为9.0时,COD和氨氮的去除率分别达到32.64%和50.42%,与模型预测结果基本一致,表明了强化PAC-PPFC复合混凝工艺预处理制肼废水是可行的。

Preparation of New Poly Silicate Iron Coagulants and Their Coagulation Property on Micro-polluted Water

The sodium silicate, ferric chloride, ferrous sulfate, sodium chlorate and other common inorganic materials were used to synthesize two new poly silicate iron coagulants： Polysilicate Ferric Chloride （PFSiC） and Polymeric Ferric Silicate Sulfate （PFSiS）. Their coagulation effect on micro-polluted water was compared with the poly ferric choride （PFC） saled in the market. The results showed that turbidity, organic matter, total phosphorus, total nitrogen removal rate ofPFSiC, PFSiS coagulant were better than PFC on micro-polluted water treatment at the same dosage. The coagulation effect of PFSiC was the best. The surface morphology of three coagulants was observed by scanning electron microscopy （SEM）, and the coagulation mechanism was discussed preliminarily.