| 摘要: | 流體化床均質化顆粒技術，嘗試在無單晶晶種的狀態下，從已處理過之低濃度廢水，進行重金屬物質之回收，使其形成重金屬均質顆粒，同時達到有價之重金屬資源化並且改善水質。鋁已於工業革命的興起至今扮演不可或缺的角色，主要產物為鋁門窗、鍍鋁製品、鋁漆和混凝劑。在此鋁回收的研究中，主要探討水質的變化對結晶化的影響。因此，在不同濃度的硝酸鹽、硫酸鹽和磷酸鹽存在時，同時改變進流濃度變化，分別為20mg.L-1、50mg.L-1和100mg.L-1。實驗結果顯示在低濃度的電解質，於較鹼性的狀態下，鋁離子可達到99%的去除率。此外在造粒的過程中，極細微的顆粒明顯受到結晶化的影響減少許多，然而結晶體最大的尺寸約為0.25毫米。這種效應與水質的離子強度變化有關，離子強度可以促進細粒的晶核生成和聚集作用，但限制晶體生長。在探討去除廢水中鋁離子方面，流體化床中出流水pH值，雙氧水與鋁的莫耳比、電解質入流濃度的最佳操作條件參數為pH9.5、1.5和 20 mg·L-1。加入電解質使其與氧化鋁生成磷酸鋁、Al(H2O)2(SO4)2Ｏ3、Al2Ca4H20N2O22和Al2H19O18PS的均質顆粒。因生成物離子強度較為高，因此結晶化的結構較為氧化鋁結晶強，並且表面也更為平整。
Fluidized-bed homogeneous granulation (FBHG) process (without seeds) allows recovering heavy metals with high purity grade from water effluents. Aluminum is one of the main impurities in industrial. The major quantities of aluminum from painting, anodizing processes at major aluminum finishing plants, and mineral coagulant. In this work, the recovery of aluminum was performed to study the water matrix influence on crystallization. Thus, the removal and granulation of aluminum was performed in the presence of different electrolytes, namely sulfate (SO42-), nitrate (NO3-), and phosphate (PO43-) while varying influent electrolyte concentration at 20 mg.L-1, 50 mg.L-1 and 100 mg.L-1. It has been observed an improvement of the pollutant removal in the presence of low concentrations of electrolytes under more alkaline pH, with 99 % achieved, of aluminum removal. Furthermore, the crystal sizes were dramatically affected diminishing the number of fines the largest around 0.25 mm but also the crystals sizes. This effect has been associated to the changes on the water matrix ionic strength that promoted the nucleation and aggregation of fines but limited the crystal growth. The optimum operating conditions for the aluminum removal were determined and the effects of effluent pH, influent electrolyte concentration in the synthetic wastewater on the aluminum removal efficiency. The best operating condition of influent electrolytes concentration were at 20 mg.L-1, molar ratio of [H2O2 : Al] was 1.5, and pH of 9.5 of the effluent wastewater. The characterized granules were confirmed that without electrolytes was Al2O3. When addition of electrolytes (SO42-, NO3-, PO43-) and combined electrolytes transformed Al2O3 into Al(H2O)2(SO4)2O3, Bi nitro aluminate, aluminum phosphate, and Sanjuanite (Al2H19O18PS), respectively. |
