| 题名 | 芳香聚酰胺中空纤维纳滤膜制备及其应用研究 |
| 作者 | 王涛 |
| 学位类别 | 博士 |
| 答辩日期 | 2015-05 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 栾兆坤 ; 赵长伟 |
| 关键词 | 纳滤膜，中空纤维，聚间苯二甲酰间苯二胺，染料，全氟辛烷磺酸, Nanofiltration membrane, Hollow fiber, Poly(m-phenylene isophthalamide), Dyes, Perfluorooctane sulfonate |
| 其他题名 | Fabrication and Application of Aromatic Polyamide Hollow Fiber Nanofiltration Membrane |
| 学位专业 | 环境工程 |
| 中文摘要 | 本文在综合分析国内外纳滤膜研究与发展的基础上，针对水处理领域对高性能、低成本纳滤膜的巨大需求，结合中空纤维膜比表面积高、制造简单、成本能耗低、效率高等特点，首次开展了以干湿相转化法制备芳香聚酰胺—聚间苯二甲酰间苯二胺（PMIA）中空纤维纳滤膜，研究了铸膜液组成、配比及制备工艺参数对膜结构及性能的影响。在此基础上，开展了 PMIA膜结构参数及性能评价和PMIA膜在印染废水和持久性有机污染物—全氟辛烷磺酸（PFOS）去除中的可行性研究，取得了如下创新性研究成果： （1）以聚间苯二甲酰间苯二胺（PMIA）为制膜原材料，系统考察了铸膜液中溶剂、聚合物浓度、有机添加剂和无机添加剂对铸膜液性质及成膜结构和性能的影响，研究并确定了空气浴、凝胶浴、牵引速度对膜结构及性能的影响，成功纺制出了一系列具有不同孔径、不同结构和性能的 PMIA中空纤维膜。所制备的中空纤维膜孔径范围在 0.5 nm~45 nm范围内，在 0.7 MPa压力下，纯水通量在45 L•m-2•h-1~86 L•m-2•h-1之间，对 Na2SO4的截留率在 20%~69%之间。为中空纤维纳滤膜的制备提供了理论指导和技术数据支持。 （2）开展了 PMIA中空纤维纳滤膜结构、分离特性及物化稳定性能的评价研究。结果表明，制备的 PMIA中空纤维膜是孔径分布较窄的荷负电性纳滤膜,表面均一平整，机械强度高。对不同无机盐的截留顺序为：R(Na2SO4)>R(MgSO4) > R(NaCl) > R(MgCl2)。可有效实现 SO42-与 Cl-的分离。且 PMIA中空纤维纳滤膜具有良好的耐压密性、耐酸碱性、耐有机溶剂性和耐高温性。 （3）系统开展了 PMIA中空纤维纳滤膜处理印染废水的可行性研究，选取酸性红（CFB）、活性黄（RY3）及直接耐晒蓝（B2RL）三种阴离子染料作为去除研究对象，考察了料液浓度、pH值、温度、盐度等因素对膜去除染料分子的影响。结果表明，所制备的 PMIA中空纤维纳滤膜对三种阴离子染料具有较好的分离性能。在压力 1.0 MPa时，PMIA膜对 CFB、RY3和 B2RL的截留率分别可达到 95.71%、96.88%和 100%。通过 PMIA膜的染料脱盐实验研究，结果表明，经过 9个循环的恒容脱盐后，染料中的盐基本除净。 （4）依据纳滤膜对小分子有机物高截留率的技术优势，开展了 PMIA中空纤维纳滤膜处理饮用水中新型持久性有机污染物--全氟辛烷磺酸（PFOS）的可行性研究，系统考察了料液浓度、pH值、离子强度等不同操作条件下，膜对水中PFOS的去除效果及膜通量的变化，分析了影响截留效率的因素并探讨了截留机理。研究结果表明，PFOS的截留率随着pH、PFOS初始浓度、Ca2+浓度、腐殖酸浓度的升高而升高。同时，Ca2+可与 PFOS发生架桥络合作用，络合之后的分子尺寸变大，膜的筛分作用增强。当 Ca2+浓度从 0.1 mM提高至 2.0 mM时，膜对 PFOS的截留率可从 97.10%提高至 99.40%。通过吸附解吸实验表明，Ca2+及腐殖酸的加入提高了 PFOS在膜表面的吸附，从而影响了膜通量和膜对 PFOS的截留率。 |
| 英文摘要 | Based on the comprehensive investigation and analysis of existing research on nanofiltration membranes in China and abroad, in consideration of the facts that the nanofiltration membranes with high separation performance and low cost are enormous needed in the fields of water treatment, and the membranes in hollow fiber configuration have the characteristics of higher surface to volume ratio and easier manufacturing technique, lower cost and energetic consumption, higher energy efficiency, a novel aromatic polyamide--poly(m-phenylene isophthalamide) (PMIA) hollow fiber nanofiltration membranes were fabricated by dry-jet wet spinning technology. The influence factors on membrane morphology structure and performance, such as dope compositions and spinning conditions, were systematically investigated, respectively. And also the structure parameters and performances were studied. At last, the feasibility for treatment of dye wastewater and a persistent organic pollutant perfluorooctane sulfonate (PFOS) using the PMIA hollow fiber nanofiltration membranes were investigated in this study, the following results were obtained as follows: (1) Hollow fiber membranes were prepared successfully using PMIA as membrane material. The influence factors on dope rheological properties, membrane structures and performances, such as solvent, polymer concentration, inorganic and organic additives, air bath, coagulation bath and take-up speed were systematically studied respectively. A series of PMIA hollow fiber membranes with different pore sizes, different morphologies and performances have been successfully prepared. It was found that the pore size of the resultant membranes was about 0.5 nm-45 nm. The properties of the prepared membranes showed that the pure water flux was about 45 L•m-2•h-1-86 L•m-2•h-1, and the rejection of Na2SO4 was about 20%~69% under the operating pressure of 0.7 MPa. The results can provide a theoretical technique foundation for the preparing hollow fiber nanofiltration membrane. (2) The pore characteristics, separation performances and physicochemical properties of the PMIA hollow fiber nanofiltration membranes were systematically investigated respectively. It was found that the resultant PMIA membrane was negative charged with narrow pore size distribution. The membrane surface was uniform, and the membrane mechanical strength was excellent. The inorganic electrolytes rejection of PMIA membrane decreased in the order of R(Na2SO4) > R(MgSO4) > R(NaCl) > R(MgCl2), and has good separation performance for SO42-/Cl-binary mixed electrolyte solutions. Furthermore, the PMIA hollow fiber nanofiltration membrane has good pressure resistance, excellent acid and alkali resistance, solvent resistance and temperature stabality. (3) The feasibility for treatment of dye wastewater using the home-made PMIA hollow fiber nanofiltration membrane was investigated. The membrane was assessed for the treatment of different anionic dyes (Chromotrope FB, Reactive Yellow 3,Direct Fast Blue B2RL) under various operating conditions, such as feed concentration, pH, temperature, salts et al. The newly developed PMIA hollow fiber nanofiltration membrane exhibited excellent removal capabilities. The rejection rate for CFB, RY3, B2RL could reach up to 95.71%, 96.88% and 100% respectively under the pressure of 1.0 MPa. Furthermore, the dyes were almost desalinized through nine times cycle during the dyes desalination filtration experiments. (4) This study investigated the separation performance of PMIA hollow fiber nanofiltration membrane for sustainable water recovery from water containing trace amount of perfluorooctane sulfonate (PFOS) that was a persistent organic pollutant commonly existed in water. The effects of feed concentration, pH, ionic strength et al.on PFOS retention and membrane flux were investigated. The results showed that PFOS rejection rate increased as the increasing of pH, feed concentration, Ca2+ concentration and humic acid concentration in the feed systems. An increase of Ca2+ concentration from 0.1 mM to 2.0 mM enhanced PFOS rejection from 97.10% to 99.40%. This is due to the fact that the size sieve effect was enhanced because of the complexation between PFOS and Ca2+. The presence of Ca2+ and humic acid enhanced the PFOS adsorption on the membrane surface and caused more pore blockage of the membrane. As such, the declination in the water flux and augmentation in the PFOS rejection were observed. |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/34439]  |
| 专题 | 生态环境研究中心_环境水质学国家重点实验室 |
| 推荐引用方式 GB/T 7714 | 王涛. 芳香聚酰胺中空纤维纳滤膜制备及其应用研究[D]. 北京. 中国科学院研究生院. 2015. |
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