| 摘要: | 本研究以富含矽鋁成分之淨水污泥灰與廢玻璃作為原料，合成出中孔徑材料MCM-41並進行表面胺官能基改質以及各項定性分析，最後於酸性環境下（pH ~ 3）進行六價鉻之吸附實驗，探討廢棄物資源化利用與處理廢水中帶負電污染物之可行性。研究結果顯示利用鹼融法與傳統水熱法將淨水污泥灰與玻璃灰製備成的中孔徑材料MCM-41粉末，於SAXS分析圖譜確定具有有序排列的六角型孔洞特徵峰出現；BET分析則指出本研究以廢棄物所合成出的中孔材料，其比表面積最高可達839 m2/g；而經由FTIR、29Si-NMR及EA的分析結果證明，本研究之迴流改質確實可達到胺基表面修飾之目的，且迴流8小時所得之胺官能基表面修飾的效果較迴流24小時為佳。此外，酸性環境下所進行的六價鉻氧化物陰離子之吸附平衡實驗結果可知，經胺官能基表面修飾後之材料較未改質前有更好的吸附效果，且經8小時改質之吸附效果比24小時好，推測可能是因為同重量之吸附劑含有較多之官能基，使得在酸性狀態下材料表面帶正電，與此時帶負電之六價鉻氧化物陰離子彼此間的靜電吸引作用所致；而等溫吸附實驗結果經吸附曲線擬合後，得知以廢棄物做為原料合成之MCM-41（液固比15）於改質前後其等溫吸附模式較符合Freundlich模式，表示材料表面吸附位置分佈並不均勻且位能不相同。綜合上述結果，證明可藉由本研究方法利用淨水污泥與廢玻璃作為合成MCM-41之替代矽鋁源料，並藉由表面胺基修飾增強對於於酸性環境下金屬氧陰離子之吸附效果，得到廢棄物資源化的效應。;In this study, ashes of water purification sludge and waste glass, two materials in which aluminum and silicate are abundant, were used as the source of silicone and aluminum to synthesize MCM-41 via the alkaline fusion method coupled with the traditional hydrothermal approach. In addition, surfaces of the MCM-41 particles were subsequently amino-functionalized for the application of chromate adsorption under acidic conditions (pH~3). The synthetic MCM-41 was characterized with a combination of SAXS, ASAP, TEM, SEM, FTIR, 29Si-NMR and EA techniques. Multiple lines of evidence first confirmed the success of the preparation processes, including (i) the observation of the signature peaks from the SAXS spectrum; (ii) the appearance of the ordered hexagonal holes from the TEM images; as well as (iii) the mesoporous property identified from the BET analysis, showing that the specific surface area of the particles was up to 839 m2/g. Further, FTIR, 29Si-NMR and EA measurements showed that the amine-refluxing method indeed resulted in the amino-functionalization on the MCM-41 surface, with 8-hr refluxing better than 24-hr. Results of the adsorption experiments conducted under acidic conditions showed that surface modification on the MCM-41 did lead to a higher chromate sorption efficiency, presumably due to the electrostatic interaction between the positively-charged surface of MCM-41 and the chromate anions at pH 3. Moreover, the adsorptive behavior was best explained by the Freundlich model, suggesting that the surface adsorption sites were not evenly distributed and the potential energy were not the same. Taken together, these results suggested that water sludge ashes and waste glass can be alternative sources of silicon and aluminum for MCM-41 synthesis, and adsorption of negatively-charged metal species such as chromate on to MCM-41 can be enhanced through appropriate functionality alternation on the surface of MCM-41. |
