本研究係利用硫酸浸漬法對淨水污泥進行回收二氧化錳之製備，於批次試驗中以不同反應時間、質量比、濃度高低參數配合，探討出最佳之錳(II)離子之浸出效率。得到 50mL 0.2M H2SO4、5mL 0.8M H2O2、實場污泥3g、反應時間5分鐘、攪拌轉速100 rpm為操作條件達到最佳之錳(II)溶出率。而後對浸漬出之溶液使用NaOH進行pH值之調整至pH 4，可使溶液中鐵(II)完全沉降而濾除，以達到純化錳離子於溶液中，以利從中製備MnO2。試驗中以KMnO4作為氧化劑，對純化後之溶液使用濃度0.02M KMnO4對55mL之溶液加熱至90℃配合磁石攪拌50rpm進行加藥，結果顯示，於提高操作條件之pH值，並採用分段加藥之加藥策略，可減少KMnO4之消耗量。經氧化後，過濾所得之產物，經X射線繞射分析儀(XRD)分析定性，確認本研究所回收之產物為γ-MnO2，此晶相之MnO2係應用於電容器產業之優秀材料。 Sludge leaching and recovery manganese from drinking water treatment sludge were investigated by using H2SO4 as a leachant. The effects of agitation, H2O2 concentration, H2SO4 concentration, liquid/solid mass ratio, leaching time and reaction temperature on manganese recovery were also studied. The optimal leaching conditions were determined as 0.2M H2SO4 and 0.8 M H2O2 using liquid–solid mass ratio of 16.7(mL/g) for 5 minutes at normal atmospheric temp with agitation rate 100 rpm. Under these conditions, the Mn2+ leaching efficiency can reach to 95%. In this study, NaOH was used to adjust the leach solution pH value to 4.0. It enabled the deposition of Fe ions in solution and formed solids that can be filtered. Therefore, we can separate manganese ions in the solution which was facilitating recovery of MnO2.For the MnO2 recovery, KMnO4 were used to perform oxidation. To increase the pH value to pH 6 of operating conditions while using two-stage addition. It was found can be reducing the consumption of KMnO4.The results from X-ray diffraction (XRD) pattern indexed to the orthorhombic phase of γ-MnO2 with lattice constants JCPDS 14-644 the recovered product of this study is γ-MnO2. Crystal phase of this outstanding material is high potential to capacitor industry application.
