Abstract:

The polysilicate ferric chlori de (PFSC)used as flocculant for seawater desalination pretreatment is prepared with pickle liquor and sodium silicate. By investigating the effect of molar ratio of Fe/Si, aging time and agingtemperature on the turbidity removal of seawater, the results showthat when the molar ratio of Fe/Si is 1.5, the value of pH is 0.5, the aging time is 1.5 h and the aging temperature is 40 ℃, the PFSC product has a wider pH range, rapid floccule forming, bulkyand massive floccules and easytodeposit. Based on the research on the seawater pretreatment for the Bohai Sea, it is found that the PFSC has a strong ability to decrease turbidity when the pH value is within 5 to 9 and it is better than PFS and FeCl₃ in the market, especially at lowdosage.

Key words: pickle liquor, polysilicate ferric chloride, seawater desalination, pretreatment

摘要：

以酸洗废液为原料制备了海水淡化预处理絮凝剂聚硅酸氯化铁(PFSC)，考察了制备过程中的铁硅比[n(Fe)/n(Si)]、熟化时间、熟化温度等因素对模拟水样絮凝效果的影响。结果表明，当n(Fe)/n(Si)=1.5、40℃熟化1.5h、pH值为0.5时制备的产品有较宽pH适用范围，形成絮体速度快，颗粒粗大密实，易沉降。对渤海海水进行了预处理应用研究，发现PFSC在pH5-9的范围内均有很好的除浊效果，絮凝效果优于市售聚合硫酸铁(PFS)和氯化铁，特别是在低投加量时表现更为明显。

关键词: 酸洗废液, 聚硅酸氯化铁, 海水淡化, 预处理

CLC Number: 

• P747

• TQ314.253