近二十年來，高技術產業在臺灣迅速地發展，也導致排放的廢水中含有各種高濃度的含氮化合物。一般氨氮廢水多以生物活性汙泥法以消化脫硝方式處理，但由於硝化菌的生長及處理速率緩慢且容易受其他環境因素影響，因此需要發展更有效率的處理方法。以濕式相轉化法製備的聚偏二氟乙烯(PVDF)薄膜，因其不對稱的結構與疏水特性可應用於薄膜接觸器以去除水中氨氮，並以硫酸水溶液作為加速分離氨之萃取液。本計畫首先利用濕式相轉換法製備PVDF 平板薄膜， 溶劑為N-methyl pyrrolidinone(NMP)，非溶劑為水；藉由改變製膜液與沈澱槽之組成，製作出一系列不同孔隙結構之薄膜。以SEM、DSC、XRD、接觸角等作為膜材物性及膜表面性質分析。設計並架設薄膜接觸器系統以去除水中氨氮，以氯化銨配置不同濃度之模擬廢水並控制pH 值為8~12，以蠕動泵輸送至薄膜接觸器，以硫酸配置0.05~0.2 M之萃取液以逆向流通入另一側。計畫第二年將以PVDF/NMP溶液以濕式紡絲法進行中空纖維膜製備，以延遲成膜法進行中空纖維膜皮層結構之最佳化，並利用水溶液為芯液，降低內表面相分離速率，增加內表面孔隙度，達到多孔性PVDF中空纖維膜結構製備出最適合薄膜接觸技術之中空纖維膜，並製成管狀模組以薄膜接觸器去處水中氨氮效率與連續式測試，及其長期穩定性的影響。 The High-Tech Industries have been rapidly developing for the last two decades in Taiwan, which also result in high concentrations of various nitrogenous compounds in the wastewater. Although biological nitrification–denitrification methods have been used in reducing ammonia–nitrogen content in sewage effluent to an acceptable level, the effectiveness of this process is restricted by slow bioconversion and unfavorable environmental factors. It is necessarily to find an efficiency process of promoting the removal of ammonia from wastewater. Polyvinylidene fluoride (PVDF) membranes with asymmetric structures and good hydrophobicity will prepare by a phase-inversion method and have been applied to removal of ammonia from water by membrane contactor. Aqueous solution containing sulfuric acid was used as stripping solution to accelerate the removal of ammonia. This research investigates the preparation and application in the membrane contactor of porous and hydrophobic PVDF membranes. PVDF membranes with different porous structures prepare by immersion-precipitation of a casting solution in coagulation baths composed of N-methyl pyrrolidinone(NMP) and water (nonsolvent). SEM, DSC, XRD, and Contact Angle analyzer use to characterize the membranes. A membrane module was prepared for ammonia stripping from water will be setup. The simulated wastewater, aqueous ammonium chloride solution to give a pH value of 8–12 is pump into the membrane contactor while the stripping solution, 0.05-0.2 M aqueous sulphuric acid solution was countercurrently fed into the other side of membrane contactor module. In the second year of the project, PVDF hollow fiber membrane spun via dry-wet spinning method to eliminate the outer dense skin layer by vapor induced phase separation (VIPS). In addition, aqueous solvent solution is use as the bore liquid to increase inner surface porosity. So that it could achieve the objective of porous morphology design. In addition, membrane contactor with tubular modules also studied theoretically and experimentally.
