摘要
采用HyflonAD60聚合物对聚偏氟乙烯(PVDF)膜进行疏水改性,并研究了膜的形态、孔径、穿透压力(LEP)、机械强度,及其在直接接触式膜蒸馏(DCMD)中的分离性能(通量、截留率和润湿性).结果表明,经外涂覆和内涂覆改性后,复合膜的疏水性和机械性能大幅提高,截留性能和润湿性能也得到明显改善,但膜的水通量下降.在采用质量分数为5%的NaCl溶液作为进料液,进料温度为65℃条件下,外涂覆15 min的膜的水通量和截留率分别达到8.03 L/(m^2·h)和99.9%以上.在相同的实验条件下,以质量分数为20%硫酸为进料,经DCMD过程浓缩12 h后,冷侧电导率从2μS/cm增加到31797.5μS/cm;而使用经外涂覆20 min的复合膜时,冷侧浓缩液的电导率最终仅升到1154.3μS/cm.这一对比进一步证明膜的抗润湿性能得到提升.
In this study,HyflonAD60 polymer was used to enhance the hydrophobicity of polyvinylidene fluoride(PVDF)membrane,and membrane morphology,pore diameter,liquid entry pressure(LEP),mechanical strength and separation performance(flux,rejection and wettability)of the membrane in direct contact membrane distillation(DCMD)were studied.The results showed that the hydrophobicity and mechanical properties of the composite membrane were greatly improved,the salt retention and membrane anti-wettability also increased obviously.Nevertheless,the water flux of the membranes was reduced.When 5%NaCl solution was used as feed and its inlet temperature was 65℃,the water flux and salt retention of the membrane coated for 15 min were 8.03 kg/(m^2·h)and>99.9%,Under the same experimental conditions,with 20%sulfuric acid as the feed,the cold side conductivity increased from 2μS/cm to 31797.5μS/cm after being concentrated by DCMD process for 12 h.When the composite membrane coated for 20 min was used,the conductivity only reached 1154.3μS/cm.This comparison further proved that the anti-wettability is better with the coated membranes.
作者
胡彪
朱杰
蒋兰英
HU Biao;ZHU Jie;JIANG Lanying(School of metallurgy and environment,central south university,Changsha 410083,China;National Engineering Research Center for Control&Treatment of Heavy Metal Pollution,Changsha 410083,China;Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety,Changsha 410083,China)
出处
《膜科学与技术》
CAS
CSCD
北大核心
2020年第1期159-170,共12页
Membrane Science and Technology
