【摘要】：本論文將以相轉(zhuǎn)化法制備的超濾膜為支撐層,再以界面聚合反應(yīng)生成的超薄功能層為復(fù)合層來(lái)制備具有較高通量的親水性復(fù)合納濾膜,并將其用于稀土回收中,探究其最佳的操作條件。研究?jī)?nèi)容包括以下三部分:以聚砜(PSF)為膜材料、聚乙二醇(PEG-600)和聚乙烯基吡咯烷酮(PVP-K30)為添加劑、N-N二甲基乙酰胺為溶劑,采用相轉(zhuǎn)化法制備超濾膜。實(shí)驗(yàn)研究了不同濃度的PSF及PEG-600、PVP-K30添加劑含量對(duì)超濾膜性能的影響規(guī)律,并得出作為支撐層的超濾膜的最佳制備條件為:PSF含量15%-17%,PEG-600含量為1.5%-2.5%,PVP含量為4%-6%。該條件下獲得的超濾膜在0.1MPa壓力下的純水通量為247-372L/m2·h,對(duì)濃度為1g/L牛血清蛋白溶液截留率為93.5%至99.4%。以哌嗪(PIP)和均苯三甲酰氯(TMC)分別為水相和有機(jī)相單體,以相轉(zhuǎn)化法制備的超濾膜為基膜,采用界面聚合法制備親水性復(fù)合納濾膜。實(shí)驗(yàn)研究了界面聚合反應(yīng)中水相單體濃度、有機(jī)相單體濃度、酸接收劑磷酸鈉添加量、界面聚合反應(yīng)時(shí)間、熱處理溫度及時(shí)間等對(duì)復(fù)合納濾膜性能的影響規(guī)律,得出親水性復(fù)合納濾膜的最佳制備工藝為:PIP濃度為1%-1.5%,TMC濃度為0.25%-0.3%,磷酸鈉濃度為1%-2%,水相反應(yīng)時(shí)間為60-70s,有機(jī)相反應(yīng)時(shí)間為55-65s,熱處理溫度為70-80℃,熱處理時(shí)間為8-12min。在該條件下制得的親水性復(fù)合納濾膜在0.6MPa下的純水通量最高可達(dá)36.78 L/m2·h,對(duì)濃度為1g/L Mg SO4的截留率均在94%以上。此外,復(fù)合納濾膜的SEM表征、AFM表征及親水性表征顯示磷酸鈉的加入有效的提高了復(fù)合納濾膜的有效膜面積及親水性。該復(fù)合納濾膜對(duì)不同價(jià)態(tài)鹽離子的截留順序依次為Na2SO4(94.76%)≈Mg SO4(94.54%)Mg Cl2(78.66%)Na Cl(42.5%),且適當(dāng)增大操作壓力將有助于提高膜通量及截留率。為考察所制親水性復(fù)合納濾膜的實(shí)際應(yīng)用性能,將其用于低濃度稀土浸出液中回收稀土離子的應(yīng)用研究。實(shí)驗(yàn)發(fā)現(xiàn),該復(fù)合納濾膜對(duì)稀土離子的截留率可達(dá)93%以上,且適當(dāng)提高進(jìn)料溫度及操作壓力可以提高截留率和通量。在1MPa壓力下,該復(fù)合納濾膜對(duì)初始濃度為0.33g/L的稀土原液進(jìn)行8小時(shí)的濃縮,即可使其濃度提高到3.48倍,滲透液中稀土離子濃度僅為0.015g/L。由此可以看出,該復(fù)合納濾膜對(duì)稀土離子具有較好的截留性能,在稀土回收中將有很好的應(yīng)用前景。
[Abstract]:In this paper, the ultrafiltration membrane prepared by phase inversion method is used as the supporting layer, and the ultrathin functional layer generated by interfacial polymerization is used as the composite layer to prepare the hydrophilic composite nanofiltration membrane with high flux, and it is used in the recovery of rare earths. Explore the best operating conditions. The research contents are as follows: ultrafiltration membrane was prepared by phase inversion method using polysulfone (PSF) as membrane material, polyethylene glycol (PEG-600) and polyvinylpyrrolidone (PVP-K30) as additives, N-N dimethyl acetamide as solvent. The effects of different concentrations of PSF and PEG-600,PVP-K30 additives on the performance of ultrafiltration membrane were studied. The optimum preparation conditions of ultrafiltration membrane were obtained as follows: 15% PSF content and 1.5 -2.5% PEG-600 content. Under this condition, the pure water flux of the ultrafiltration membrane obtained under 0.1MPa pressure is 247-372L/m2 h, and the rejection rate of 1g/L bovine serum protein solution is 93.5% to 99.4%. Hydrophilic composite nanofiltration membranes were prepared by interfacial polymerization with piperazine (PIP) and trimethoyl chloride (TMC) as aqueous and organic monomers and ultrafiltration membranes prepared by phase inversion method. The effects of water monomer concentration, organic monomer concentration, acid receiver sodium phosphate addition, interfacial polymerization time, heat treatment temperature and time on the properties of composite nanofiltration membrane were studied experimentally. The optimum preparation process of hydrophilic composite nanofiltration membrane was obtained as follows: 1% PIP concentration 1-1.5 and TMC concentration 0. 25-0. 3, sodium phosphate concentration 1-2 and water phase reaction time 60-70 s, organic phase reaction time 55-65 s, heat treatment temperature 70-80 鈩，

本文編號(hào)：2255078