纳滤-反渗透技术用于高盐废水中NaCl的回收

为了实现高盐废水中NaCl的回收,采用纳滤-反渗透双膜串级组合工艺,处理NaCl和Na₂SO₄的混合模拟废水,考察了浓度配比、操作压力、流速及温度等工艺参数对膜分离效果的影响,并确定出了最佳工艺参数.实验结果表明:在最佳工艺参数下,经纳滤和反渗透分离后的反渗透浓缩液中,NaCl]/Na₂SO₄]≥41.45,可实现NaCl和Na₂SO₄的有效分离;反渗透膜对Cl^－的截留率达到96%以上,回收得到的NaCl其纯度可达到97.5% 以上.

Nanofiltration-reverse osmosis process for recovery NaCl in high-salt wastewater

In order to realize the recovery of NaCl in high-salt wastewater, a nanofiltration-reverse osmosis double-membrane cascade combined process was used to purify the mixed simulated wastewater contained NaCl and Na₂SO₄. The concentration ratio, operating pressure, flow rate and temperature were investigated, and the most excellent technical conditions were determined. The experimental results showed that the value of NaCl]/Na₂SO₄] was not less than 41.45 in reverse osmosis concentrate, which indicated that the process can achieve separation of NaCl and Na₂SO₄ effectively; In addition, the reverse osmosis membrane can separate Cl^－ with the rejection rate of Cl^－ more than 96%, and the purity of the recovered NaCl can reach over 97.5%.