摘要
提高膜表面的疏水化及液体进入压力(LEP)是减缓膜蒸馏过程中膜污染问题的有效策略.以聚偏氟乙烯(PVDF)中空纤维膜为基膜,采用浸渍涂覆-固化法将乳液组装到PVDF膜表面,制备了具有抗污染性能的复合膜.探究了涂覆时间对膜的形貌及性能的影响,并考察了复合膜的抗污染和抗结垢性能.结果表明,当涂覆时间为20min时,复合膜的水接触角达到115°,LEP达到0.75 MPa.在DCMD浓缩实验中,复合膜在分别处理质量分数3.5%NaCl、质量浓度50 mg/L的HA和14.7 mmo/L CaSO_(4)水溶液时,膜通量稳定,冷凝液电导率保持在10μS/cm以内,表现出优异的抗污染和抗结垢性能.此外,考察了中空纤维复合膜的稳定性.结果表明,复合膜在浓缩质量分数3.5%NaCl水溶液时,膜通量为16 kg/(m^(2)·h),冷凝液电导率保持在15μS/cm以内,表现出良好的长期稳定性能.
Hydrophobization of membrane surface and high LEP are effective strategies to mitigate membrane fouling during membrane distillation.The composite membranes with anti-fouling properties were prepared by anchoring the emulsion on the PVDF hollow fiber porous membrane surface using the dip-coating-curing method.The effects of coating time on the morphology and properties of the membranes were investigated,and the anti-scaling and anti-fouling properties of the composite membranes were studied.The results showed that when the coating time was 20 min,the contact angle of the composite membrane reached 115°and the LEP reached 0.75 MPa.In the DCMD concentration experiment,the composite membrane maintained the flux when treating 3.5%NaCl,50 mg/L HA and 14.7 mmol/L CaSO_(4)aqueous solution,respectively,showing excellent anti-fouling and anti-scaling performance.In addition,the stability of hollow fiber composite membrane was investigated.The results show that when the hollow fiber composite membrane concentrates 3.5%NaCl aqueous solution,the osmotic flux is 16 kg/(m^(2)·h),and the condensate conductivity is less than 15 μS/cm,showing good long-term stability.
作者
晋墩尚
谢松辰
李志霞
宋旭峰
彭跃莲
JIN Dunshang;XIE Songchen;LI Zhixia;SONG Xufeng;PENG Yuelian(Faculty of Environment and Life,Beijing University of Technology,Beijing 100124,China)
出处
《膜科学与技术》
CAS
CSCD
北大核心
2022年第5期129-138,共10页
Membrane Science and Technology
基金
国家自然科学基金项目(21878005)。
关键词
PVDF中空纤维膜
浸渍涂覆-固化
抗污染
抗结垢
膜蒸馏
PVDF hollow fiber membranes
dip coating-curing
anti-fouling
anti-scaling
membrane distillation
