Abstract: Floc can be formed by using Kaolin water distribution water sample as research target,combining magnesium chloride with ferric chloride by on-line intelligent Particle Dispersion Analyzer (iPDA). The coagulation capacity and floc characteristics of using separate magnesium chloride and ferric chloride,and that of using combined magnesium-ferric composite are discussed. The results show that under conditions as follows:20 NTU and water sample pH=11.5,the optimum dosages of magnesium ions and ferric ions are 7.2 mg/L and 21 mg/L,respectively. As to combining magnesium chloride with ferric chloride,magnesium chloride should be added first,and then ferric chloride,at an interval of 20 s. In this case,the coagulation capacity is better. When the optimal dosage of magnesium ions is 7.2 mg/L,ferric ions 21 mg/L,and m (Fe³⁺):m (Mg²⁺)=1:2, the coagulation capacity is better. When magnesium and ferric are combined,its FI is obviously greater than that of being used separately. Synergistic effect occurs,and,as a result,the deficiency happened in the course of coagulation caused by using magnesium salt singly can be made up.

Key words: magnesium hydroxide, coagulation, floc, ferric hydroxide

摘要： 以高岭土配水水样为研究对象，复配氯化镁和氯化铁，运用在线激光光散射测定仪iPDA监测混凝过程絮体形成，探讨了单独使用氯化镁和氯化铁及镁铁复配的混凝效果和絮体特性。结果表明：对20 NTU、pH=11.5水样，氯化镁、氯化铁最佳投加量分别为7.2、21 mg/L；氯化镁和氯化铁复配时，先投加氯化镁，间隔20 s投加氯化铁，混凝效果较好；在氯化镁最佳投加量7.2 mg/L，m（Fe³⁺）：m（Mg²⁺）=1：2时效果较好；镁铁复配时其FI明显大于单独作用时，发生了协同效应，弥补了单独使用镁盐混凝过程的不足。

关键词: 氢氧化镁, 混凝, 絮体, 氢氧化铁

CLC Number: 

• X703.1