高性能内压式中空纤维纳滤膜的制备及其性能

Preparation and properties of high performance internally pressurized hollow fiber nanofiltration membrane

纳滤(NF)膜在海水软化和废水回收利用等方面已经被广泛应用.内压式中空纤维(HF)NF膜因其填充密度大、皮层不易被破坏等特点具有广阔的发展前景.以自制的聚砜(PSf)HF超滤(UF)膜为基膜,采用界面聚合(IP)法,分别以哌嗪(PIP)和均苯三甲酰氯(TMC)为水相和油相单体,以十二烷基硫酸钠(SDS)和三乙胺(TEA)为水相添加剂,在基膜内表面完成IP反应,制备出内压式HFNF膜.考察了水相流速、氮气吹扫时间、PIP浓度以及TEA浓度对内压式HFNF膜分离性能的影响.结果表明,最优条件下制备的内压式HFNF膜在0.4 MPa的测试条件下,对于2 000 mg/L的硫酸钠(Na_(2)SO_(4))溶液中的Na_(2)SO_(4)截留率可达97.3%,水渗透率达93 L/(m^(2)·h·MPa);对于2 000 mg/L的硫酸锌(ZnSO_(4))、硫酸锰(MnSO_(4))溶液中的ZnSO_(4)、MnSO_(4)的截留率均达到93%以上.所制备的内压式HFNF膜有良好的耐污染性能和耐氯性能.

Nanofiltration(NF) membrane has been widely used in seawater softening and wastewater recycling. Internally pressurized hollow fiber(HF) NF membrane has broad development prospects as it possesses high filling density and difficult to damage the polyamide layer. In this paper, polysulfone(PSf) HF ultrafiltration membrane was used as the substrate membrane, the internally pressurized HFNF membrane was prepared by interfacial polymerization(IP) on the inner surface of the substrate membrane with piperazine(PIP) and trimesoyl chloride(TMC) as aqueous and organic monomers and sodium dodecylsulfate(SDS) and triethylamine(TEA) as aqueous additives. The effects of water phase flow rate, N_(2) purging time, PIP concentration and TEA concentration on the separation performance of internally pressurized HFNF membrane were studied. The performance test results showed that the internally pressurized HFNF membrane prepared under the optimal conditions had higher water permeability of 93 L/(m^(2)·h·MPa) and the Na_(2)SO_(4) rejection of 97.2% for 2 000 mg/L Na_(2)SO_(4) solution at 0.4 MPa. For 2 000 mg/L heavy metal salt solution, the rejection of ZnSO_(4) and MnSO_(4) in ZnSO_(4) and MnSO_(4) solution could reach 93%. Moreover, the prepared internally pressurized HFNF membrane showed good anti-fouling performance and chlorine resistance performance.