中孔洞二氧化矽/殼聚醣複合膜應用於奈米過濾之研究

Abstract

為了解決高鹽度染料廢水直接排放所造成的環境汙染問題，開發高效率且低耗能的淨化技術用於的染料廢水淨化是迫切需要的，然而，常用的傳統淨化技術如化學降解法、吸附法都難以高效率地淨化的染料廢水。由於奈米過濾技術具有低耗能且對環境較友善的特性，因此在染料廢水淨化中有極大的應用潛力。 近年來，為了實現高效率的染料廢水淨化，並通過增加過濾膜的膜通量來降低耗能，許多文獻結合了多孔材料的滲透性與高分子的柔性及易於成膜的優勢製成複合基材膜 (mixed matrix membranes, MMMs) 。本研究通過具有垂直通道的中孔洞二氧化矽薄膜SBA⊥15作為過濾主體，將其與殼聚醣高分子結合製成複合基材膜以提升奈米過濾的效率，通過分別修飾不同官能基調控SBA⊥15之表面特性，如環氧基 (SBA⊥15-Epo) 及胺基 (SBA⊥15-NH2) ，實現了其與殼聚醣的共價鍵結合進而增加複合體系的相容性和機械強度。實驗結果證實，SBA⊥15-Epo/殼聚醣複合膜表現出最佳的奈米過濾性能，對分子量大於585 g / mol的染料表現出90%以上的阻擋率，並具有優於單純殼聚醣過濾膜的膜通量，此外，在染料/鹽類混合水溶液的選擇性過濾分離實驗中，SBA⊥15-Epo/殼聚醣複合膜對染料分子和無機鹽類表現出高效的選擇性分離性能，對剛果紅分子 (Congo red, M.W.=696.67) 表現出99.9%以上的阻擋率及85%的氯化鈉 (NaCl) 滲透率，因此，該SBA⊥15-Epo殼聚醣複合膜體系在染料廢水淨化中有很大的應用潛力。

Textile dye wastewater with high salinity is directly discharge every year, causing serious environmental pollution and water resource waste. Consequently, it is imperative to design effective approaches for dye recycle and selective dye/inorganic salt separation from textile dye waste water. However, traditional technologies, such chemical degradation and adsorption, are inadequate for this purpose. Nanofiltration (NF) technology becomes an attractive alternative for effective removal of textile dyes from wastewater and dye desalination due to its environment friendliness and low energy consumption. In recent years, in order to achieve efficient nanofiltration, porous fillers were utilized to prepare the mixed matrix membranes (MMMs). Herein, SBA⊥15, a mesoporous thin film with perpendicular nanochannel, was selected as a filler and mixed with chitosan polymer as nanofiltration membranes. By functionalizing amino and epoxy groups into SBA⊥15, respectively, covalent bonds between amine-functionalized, epoxy-functionalized SBA⊥15 (SBA⊥15-NH2 and SBA⊥15-Epo) with chitosan were formed so as to improve the compatibility between SBA⊥15 and polymer. As a result, SBA⊥15-Epo/Chitosan MMM demonstrates superior nanofiltration performance for various dye molecules with a cut off of 585 g/mol and improved water permeance compared with chitosan membrane. Besides, the excellent performance in selective separation of dye/salt in mixed solution was demonstrated, with 99.9% rejection of Congo red and 85% permeation of NaCl. Thus, the SBA⊥15-Epo/Chitosan is highly potential in purification of textile dye wastewater.