国产纳滤膜淡化高氟苦咸水基础研究

Basic studies on the performance of domestic nanofiltration membranes for desalting brackish water with high fluoride

实验选取两种国产纳滤膜NF2A和NF3A进行纳滤膜淡化高氟苦咸水的基础研究,考察操作压力、温度、进水pH、进水氟浓度、总含盐量（TDS）及运行时间对纳滤膜分离性能的影响,并测定膜的Zeta电位,同时简单比较两种膜。研究结果表明,两种纳滤膜处理高氟苦咸水的理想操作条件为：压力1.0~1.5 MPa,温度20℃,进水pH=6.5左右,在此条件下NF3A纳滤膜的脱盐率为79%,脱氟率为90%,产水通量为53L/（m^2·h）,NF2A纳滤膜的脱盐率分别为73%,73%和71L/（m^2·h）,此外,随进水氟浓度和总含盐量的增大,纳滤膜的脱氟和脱盐率降低,同时得出两种膜在长期运行72h内膜性能基本保持稳定,最后测得NF3A和NF2A的Zeta电位分别为-22和-18mV。这项研究为国产纳滤膜处理高氟苦咸水的实际应用提供了技术数据,有利于国产纳滤膜的发展和完善.

In this study, the performances of two domestic NF membranes （NF2A and NF3A） for defluorinating brackish water with high fluoride were studiedand compared. And the influences of pressure, temperature, pH, fluoride concentration, total dissolved solids and running time were studied by a pilot unit test. And the Zeta potential of the two NF membranes was detected. Then the optimum condition was identified as followings： Pressure 1.0-1.5 MPa, Temperature 20 ℃, pH=6.5. Under this condition,the desalination rate, the defluorination rate and the water flux of NF3A membrane were 79%, 90% and 53 L/（m^2 · h）, while that of the NF2A membrane was 73%, 73% and 71 L/（m^2 · h）, respectively. And as a result of the increasing of fluoride concentration and TDS, the defluorination ratedecreased. Meanwhile,the results of long-term operation （72 h） showed that the permeability of the membrane remained stable. Finally, the Zeta potential of NF3A and NF2A was -22 and -18 inV. This research will provide technical references to the practical application of domestic NF membranes in the treatment of brackish water, and promote andimprove the development of domestic NF membranes.