CAJ | 학술논문

研究了多效膜蒸馏（MEMD）过程对氢氧化钠稀溶液的浓缩回收。结果表明，该过程可将NaOH稀溶液浓缩至250 g/L以上，且截留率维持在99.9%以上；虽然NaOH溶液的黏度和沸点随着浓度上升而急剧上升使得膜通量和造水比都显著下降，但是当NaOH质量浓度达到200 g/L时膜通量和造水比仍可达3.05 L/（m2·h）、5.04，达到相当于7效蒸发器的节能效果。膜组件在连续运行的60 d内保持了良好的操作稳定性。
연구료다효막증류（MEMD）과정대경양화납희용액적농축회수。결과표명，해과정가장NaOH희용액농축지250 g/L이상，차절류솔유지재99.9%이상；수연NaOH용액적점도화비점수착농도상승이급극상승사득막통량화조수비도현저하강，단시당NaOH질량농도체도200 g/L시막통량화조수비잉가체3.05 L/（m2·h）、5.04，체도상당우7효증발기적절능효과。막조건재련속운행적60 d내보지료량호적조작은정성。
Multi-effect membrane distillation (MEMD) process used for the concentration and recovery of dilute aqueous solution of sodium hydroxide has been studied. The experimental results show that the dilute solution could be successfully concentrated to>250 g/L by using MEMD process ,and the rejection coefficient R>99.9%. The vis-cosity and boiling point of NaOH solution increase rapidly with the increase of the concentration,and,as a result, both of the membrane flux and water producing ratio decrease significantly ,but when NaOH concentration reaches 200 g/L,the membrane flux and water producing ratio can still reach 3.05 L/(m2·h) and 5.04,respectively,which e-quals to the energy-saving efficiency of a 7-effect evaporator. Within 60 d the continuously running membrane mod-ules have kept very good operational stability.