本研究確立可透過流體化床均質造粒程序從合成螺絲廢水中回收高純度重金屬－「鋅」。實驗中使合成廢水中鋅的濃度保持在每公升500毫克。研究變數包含氯化物濃度、流出水體酸鹼值及CO32-與Zn2+ 之莫耳比。本反應系統造粒的最佳操作參數為CO32-與Zn2+莫耳比為1.2，廢水酸鹼值為7.2。氯化物會干擾鋅的沉澱與造粒，在沒有氯化物干擾的情況下，去除和造粒效率分別為97.60%與92.49%。然而，氯化物在5000mg/L的情況下，去除和造粒效率分別會明顯下降到89.29%與86.67%。氯離子在低於5000mg/L的情況下，則對於鋅的去除率並無顯著性差異。本程序是以水鋅礦顆粒形式回收鋅，通過X-射線繞射分析證實，其顆粒直徑達1.0毫米。以能量色散X-射線光譜分析元素組成，比較氯化物的存在與不存在，其鋅含量分別為63.71%與63.08%。流化床均勻顆粒化技術是晶種結晶技術的有效替方案，而且因為產品的純度較高，回收潛力高，所以可降低操作總成本。 This research studied the recovery of zinc from screw-production wastewater by fluidized-bed homogeneous granulation process by using synthetic zinc wastewater with constant concentration at 500 mg/L. The studied variables included chloride, pH, and CO32-:Zn2+ molar ratio. The results show that the optimum conditions for hydrozincite granulation were molar ratio of CO32-:Zn2+ of 1.2, and pH at 7.2. Chloride interfered zinc precipitation and granulation. In the absence of chloride, removal and granulation efficiencies were 97.60% and 92.49%, respectively. However, the removal and granulation efficiencies significantly dropped to 89.29% and 86.67%, respectively, in the presence of 5,000 mg/L of chloride. Considering on the system operating manner, there was no significant difference in zinc removal between the absence and presence of chloride. The largest hydrozincite granule has the diameter of 1.0 mm. Elemental composition analysis of the hydrozincite in the absence and presence of chloride revealed that there were 63.71% and 63.08% of zinc content, respectively.
