双组分无机电解质溶液的纳滤膜分离性能

纳滤膜是20世纪90年代问世的新型分离膜，具有两个显著特点：一是其截留分子量介于反渗透膜和超滤膜之间，约为2002000；另一是纳滤膜的表面分离层由聚电解质构成，一般带有负电荷，因此对无机电解质有一定的截留率．

Separation performance of nanofiltration membranes for binary electrolyte solutions

Investigations have revealed the permeation performance of electrolytes in the separation process by nanofiltration membranes in single salt solutions. However, there is still not much information about the separation process of mixed electrolyte solutions, and by now most of the investigations have been on solutions containing three kinds of ions, in which anions are mostly NO-_3, Cl- and SO 2-_4, and cations are mostly Na ,Ca 2 and Mg 2 . In this work, permeation experiments of three kinds of nanofiltration membranes(ESNA 1-LF, ESNA 1 and LES 90) for binary electrolyte solutions(NaNO_3, Ca(NO_3)_2; NaCl, NaNO_3; NaCl, Ca(NO_3)_2; etc.) were carried out, and the interactions between co-ions and counter-ions were investigated.The result showed that the ion with better permeation performance would permeate first,thus depressing the rejection of itself and enhancing the rejection of the co-ion with poor permeation performance. Interaction between co-ions with similar permeation performance was not obvious. Counter-ions influenced each other mainly through the electroneutrality principle.