氢氧化镁混凝过程絮体形成研究  

Study on the floc formation in the process of magnesium hydroxide coagulation

作　　者：刘文娟[1] 赵建海[1] 李文朴[1] 封娜[1] 

机构地区：[1]天津城市建设学院环境与市政工程系,水质科学与技术天津市重点实验室,天津300384

出　　处：《环境污染与防治》2011年第10期43-47,共5页Environmental Pollution & Control

基　　金：天津市应用基础及前沿技术研究计划项目(No.10JCYBJC05700);河北省教育厅自然科学研究指导项目(No.Z2009110)

摘　　要：以不同浊度高岭土水样为研究对象,运用激光光散射法对氢氧化镁混凝剂絮体开始形成时间和氯化镁最小投加量进行测定,探讨了氯化镁投加量对沉后出水浊度和Zeta电位的影响。结果表明:(1)氢氧化镁混凝剂絮体开始形成时间随着氯化镁投加量的增大而缩短;pH增大及浊度增大时,絮体开始形成时间总体缩短,pH=11.5、氯化镁投加量为25.20mg/L时,浊度为5.0、8.0NTU的水样,絮体开始形成时间分别为12、8s;(2)随着浊度增大,氯化镁最小投加量也随之减小;(3)随着氯化镁投加量的增大,沉后出水浊度呈先减小后增大的趋势;(4)混凝剂能够使溶液Zeta电位绝对值减小,氯化镁投加量为14.40mg/L、浊度为8.0NTU的水样在投加混凝剂前后电位分别为-18.50、-5.85mV。Laser method was applied to determine the floc formation time of magnesium hydroxide coagulant and the minimum coagulation dosage in different turbidity of kaolin water samples.The effects of coagulant dosing quantity on effluent turbidity and Zeta potential were also discussed.The results showed that the floc formation time was decreased with increasing the coagulant dosage,pH and initial turbidity.When MgCl2 dosage was 25.20 mg/L and pH was 11.5,the floc formation time was 12 s and 8 s respectively for 5.0 NTU and 8.0 NTU of water sample.The larger of initial turbidity,the smaller of minimum coagulation dosage.With increasing the coagulant dosage,the effluent turbidity presented the tendency of decreased first and then increased.The Zeta potential was reduced when MgCl2 was fed to water sample.For the water sample with initial turbidity of 8.0 NTU,the Zeta potential was changed from-18.50 mV to-5.85 mV after the cagulation.

关 键 词：氢氧化镁 氯化镁 混凝 絮体 

分 类 号：X703[环境科学与工程—环境工程]