基于超滤的放射性废水中^(90)Sr去除技术研究

Removal of^(90)Sr From Aqueous Solution Based on Technology of Ultrafiltration

以Na_(2)CO_(3)及Na_(3)PO_(4)为沉淀剂,MnO_(2)为吸附剂,将化学沉淀、吸附与超滤相结合,研究不同条件下超滤对放射性废水中Sr^(2+)的截留性能。结果表明,提高溶液pH是增大超滤对Sr^(2+)截留率的一种有效手段,当溶液pH值为11.78时,超滤对Sr^(2+)的截留率可达95%;增加Na_(2)CO_(3)及Na_(3)PO_(4)用量可显著提高超滤对Sr^(2+)的截留率,Na_(2)CO_(3)及Na_(3)PO_(4)的最佳用量分别为2 g/L、0.7 g/L,这时超滤对Sr^(2+)的截留率分别为98.59%、98.59%,同等条件下,添加Na_(3)PO_(4)后超滤对Sr^(2+)的截留率优于添加Na_(2)CO_(3);MnO_(2)为一种性能优良的Sr^(2+)吸附剂,Sr^(2+)截留率随MnO_(2)用量的增加而增大,为了充分利用MnO_(2)的吸附性,采用MnO_(2)吸附Sr^(2+)时应使其与溶液充分接触2 h以上。

This study characterized the removal of strontium from aqueous solution via precipitation and adsorption followed by ultrafiltration.Na_(2)CO_(3)and Na_(3)PO_(4)were used as the precipitating agent,and MnO_(2)was used as adsorbent.The results showed that increasing of the pH value of solution was an effective way to increase the rejection rate of Sr^(2+)by ultrafiltration.When the pH value of solution was 11.78,the rejection rate of Sr^(2+)by ultrafiltration could reach 95%.Increasing of the amount of Na_(2)CO_(3)and Na_(3)PO_(4)could significantly increase the rejection rate of Sr^(2+)by ultrafiltration,and the optimal dosage of Na_(2)CO_(3)and Na_(3)PO_(4)were 2 g/L and 0.7 g/L repectively.Under the optimal dosage,the rejection rate of Sr^(2+)by ultrafiltration were both 98.59%.Under the same conditions,the rejection rate of Sr^(2+)by ultrafiltration after adding Na_(3)PO_(4)was better than adding Na_(2)CO_(3).MnO_(2)was an excellent adsorbent for Sr^(2+).The rejection rate of Sr^(2+)by ultrafiltration increased with the increase of dosage of MnO_(2).In order to make full use of MnO_(2),MnO_(2)should contact with solution for more than 2 hours.