DuYongliang,SunZengxu,HeShaolin,et al.Influence of Multi-stage Nanofiltration Operation Mode on Desalination and Salt Separation of High-salinity Wastewater[J].China Water & Wastewater,2026,42(13):92-98.
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Influence of Multi-stage Nanofiltration Operation Mode on Desalination and Salt Separation of High-salinity Wastewater

China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU] volume: 第42卷 Number: 第13期 Page: 92-98 Column: Date of publication: 2026-07-01
Author(s):
Du　Yongliang1;  Sun　Zengxu1;  He　Shaolin2; 3;  Yuan　Hongying1; 3;  Qiao　Hongwei1;  Li　Mengkai4
（1. Tianjin Key Laboratory of Aquatic Science and Technology， School of Environmental and Municipal Engineering， Tianjin Chengjian University， Tianjin 300384， China； 2. Beijing Zhonglu Consulting Co. Ltd. ， Beijing 100089， China； 3. The Ecology and Environment Branch of State Center for Research and Development of Oil Shale Exploitation， Beijing 100089， China； 4. Tianjin Chenchuang Environment Engineering Science & Technology Co. Ltd.， Tianjin 300384， China）
Keywords:
high-salinity wastewater;  multi-stage nanofiltration;  operation mode;  desalination;  salt separation
Abstract:
In order to investigate the desalination and salt separation performance of a multi-stage nanofiltration (NF) system for high-salinity wastewater, a multi-stage NF unit with different operation modes was constructed using VONTRON VNF1-4040 NF membranes. The results showed that under the same operating conditions and varying membrane flux, the rejection rates of Cl- and SO42- in the split-flow operation mode were generally higher than those in the parallel-flow operation mode. Increasing the membrane flux, as well as decreasing the influent temperature and concentration, the ion rejection rate of the system was improved. The desalination and salt separation performance of the multi-stage NF system varied significantly for salt-containing solutions of different compositions, and the split-flow operation mode exhibited better separation performance than the parallel-flow mode. When the mass ratio of NaCl to Na2SO4 in the raw water were 1∶9 and 1∶4 under the split-flow operation mode, the mass concentration ratios of NaCl in the produced water and that of Na2SO4 in the concentrated water exceeded 94.6% and 97.0%, respectively. After concentration and drying, the inorganic salt content could meet the relevant industrial product standards.
Last Update: 2026-07-01