低浓度范围内盐浓度对纳滤膜截留性能的影响

发布时间：2018-05-30 15:40

本文选题：纳滤膜 + 截留率　；参考：《膜科学与技术》2017年01期

【摘要】：采用Desal-DK有机纳滤膜分别对低浓度范围(1~50mol/m~3)的KCl、NaCl、Na_2SO_4、K_2SO_4、MgCl_2水溶液进行纳滤实验,考察盐的浓度及类型对截留率的影响,结合道南细孔-介电DSPM-DE模型计算等效荷电密度(Xd),孔内介电常数(εp),采用DSPM模型计算等效膜孔半径(rp),研究不同类型盐的截留率变化和Xd、εp、rp的关系.结果表明,Na_2SO_4、K_2SO_4的截留率变化趋势和KCl、NaCl相同,随着盐浓度的增加而降低,其原因归结于随着浓度的增加|Xd|增加,电荷屏蔽作用增强,道南电势减弱;MgCl_2的截留率随着盐浓度的增加而升高,原因是浓度的增加Mg~(2+)与膜的羧基不断发生特性结合,|Xd|升高,εp降低,静电排斥作用变大和介电排斥作用增强的双重作用.
[Abstract]:The Desal-DK organic nanofiltration membrane was used to study the effects of salt concentration and type on the retention rate of KCl-NaCl-Na2SO4 / K2SO4 / MgCl2 in the low concentration range of 50 mol-1 / mc3 respectively, and to investigate the effect of salt concentration and type on the rejection rate of KCl-NaCl-Na _ 2SO _ 4S _ 2SO _ 4T _ 2SO _ 4 / MgCl _ 2. The equivalent charge density (XD) and internal dielectric constant (蔚 PX) were calculated by using the DSPM-DE model. The equivalent membrane pore radius was calculated by using the DSPM model. The relationship between the rejection rate of different salt types and the relation between XD and 蔚 Pnrp was studied. The results showed that the change trend of the rejection rate was the same as that of KCl-NaCl, and decreased with the increase of salt concentration. The reason was that with the increase of Xd concentration, the effect of charge shielding was enhanced. The rejection rate of Daonan potential decreased and the rejection rate of MgCl2 increased with the increase of salt concentration, because the increase of concentration of Mg~(2) combined with the carboxyl group of the membrane, Xd increased, 蔚 p decreased, electrostatic repulsion increased and dielectric repellent increased.
【作者单位】：南京工业大学材料化学工程国家重点实验室;
【基金】：国家支撑计划(2013BAE11B03)
【分类号】：TQ051.893

【参考文献】