基于Donnan分离的磷酸盐离子迁移与膜内分布

基于Donnan分离原理,研究磷酸盐离子在无电压条件下通过阴离子交换膜的迁移过程以及膜内磷酸盐的分布。结果表明,阴离子交换膜采用NaCl溶液浸泡预处理后,促进磷酸盐离子的第1步迁移过程,磷酸盐离子的迁移去除效果提高5%。受体液NaCl浓度是阴离子交换膜内磷酸盐含量的控制因素,其浓度从0.001 mol/L增加至0.1 mol/L时,膜内磷酸盐含量由0.077 mg/cm2降至0.002 mg/cm2。受体液NaCl浓度较高时,有利于促进磷酸盐离子的第3步迁移过程,且2层膜内磷酸盐含量的分布由给体液至受体液呈递减趋势。温度升高,低浓度受体液条件下膜内磷酸盐的含量增加,对高浓度受体液条件下膜内磷酸盐的含量几乎无影响。

Phosphate transport and distribution in membranes based on Donnan dialysis

Transport process of phosphate ions through anion-exchange membranes and its distribution were investigated without supplying electrical potential based on Donnan dialysis principle.Results show that the first transport process of phosphate ions is promoted using pretreated anion-exchange membrane immersing in NaCl solution,and removal efficiency of phosphate increases by 5%.NaCl concentration in receiver solution is leading factor controlling amount of phosphate in an anion-exchange membrane.Increasing NaCl concentration from 0.001 mol/L to 0.1 mol/L,amount of phosphate in the membrane decreases from 0.077 mg/cm2 to 0.002 mg/cm2.Higher NaCl concentration in receiver solution facilitates the third transport process of phosphate ions,and quantity of phosphate distribution in two overlapping membranes presents descending trend from side of feed solution to side of receiver solution.When phase temperature increases,it results in amount of phosphate in membranes increased if NaCl concentration in receiver solution is at low level,but it has little effect on amount of phosphate in membranes if NaCl concentration is at high level.