高盐分低放射性废水膜蒸馏处理技术研究

Research on High Salinity-Low Radioactive Wastewater Treatment by Membrane Distillation

采用管式膜蒸馏组件以气隙式方式处理模拟高盐分低水平放射性废水,研究温度、流量和盐(Ca(NO3)2+Al(NO3)3)含量对膜蒸馏通量与截留率的影响,验证该组件对高盐分低放废水的净化效果。结果表明,热侧温度、流量的增大均会显著提高膜通量,盐含量升高时膜通量呈下降趋势,当盐质量浓度达320 g/L时,通量约降为初始的2/3,总截留率大于99.8%;当冷侧、热侧温度分别控制在20、65℃,冷侧、热侧体积流量均控制在2 m3/h时,膜蒸馏运行效果为佳。废水净化系数大于103,控制指标远低于GB 8978-1996排放标准。

Tubular membrane distillation component with air gap type was used to treat simulated high salinity- low radioactive wastewater, the effect of temperature, flow rate and salt content （Ca（NO3）2＋Al（NO3）3） on membrane distillation （MD） flux and studied, the wastewater purification effect by the component was verified. The results showed that, the membrane flux increased with the increase of hot side temperature and flow rate and decreased with the increase of salt content. When the mass concentration of salt was 320 g/L, the flux was reduced to about two-thirds of the initial, total rejection rate was greater than 99.8%. When the temperature of cold and hot side was 20 ℃ and 65 ℃ respectively, and the volume flow rate of cold and hot side was 2 m3/h, the MD operation effect was optimal. The decontamination factor was more than 103, and the index was controlled less than the discharge standard of GB 8978-- 1996.