| 摘要: | 台灣每年均產生數量龐大的污泥及焚化灰渣，諸如燃煤電廠飛灰、水庫淤泥、上水與下水污泥，以及都市垃圾與工業廢棄物之焚化灰渣，必須極待妥善處理、處置以及整合之管理。國內在自然資源匱乏與處置場址難求等困境下，減量與資源化成為廢棄物管理的重要方向。目前對於污泥、灰渣類等廢棄物資源化，還是偏向成生態水泥、營建砂石骨材、路基材料、製磚等相關研究為主，可惜此方面的應用附加價值不高，且僅少數部分應用在水泥原料或路基材料，其餘的最終還是轉向掩埋處置。因此開發關鍵技術，以提升資源化產品附加價值，尋求新的再利用途徑，取之於廢棄物，用之於環境淨化（作為環境淨化材料），在環境保護與資源循環上極有意義。廢棄污泥、灰渣，尤其是每年產量驚人的燃煤電廠飛灰、淨水污泥、下水污泥，以及晶圓廠之化學研磨機械廢水污泥等本質上都蘊含許多可再利用的無機資源。綜觀上述污泥、灰渣之性質，其成分大多為SiO2、Al2O3 組成的矽鋁酸鹽礦物相，不難發現此組成是與形成天然沸石(nature zeolite)的火山灰相似，若能善加利用此資源，合成出具沸石分子篩結構的多孔材料是有可行性的。中孔徑多孔材料具有多種優異之性能，如：孔洞大小分佈均勻一致、孔洞大小具有可調整性、具有高表面積(BET 表面積約1000m2/g)，可對環境中的汙染物進行吸附或催化。傳統中孔徑分子篩的合成還是以矽基材為主，但這種純矽質的分子篩離子交換能力小、水熱穩定性不佳，以及非常弱的布忍斯特酸位 (Brǿnsted acid)，實際應用在吸附分離及催化反應上將受到限制。過去文獻已證實，含鋁的中孔徑矽基材可在表面產生酸性位置以增加酸性，還可防止Si-O-Si 鍵被水解，提高在水熱環境下的結構穩定性。鋁矽質的中孔徑多孔材料主要是由帶負電荷的無機物與帶正電荷的界面活性劑經過自組合(self-assembly)的過程所形成的產物，而矽氧化物的來源可以是矽酸鹽溶液，如矽酸鈉(sodium silicate)、有機矽化物，如四乙基氧矽(TEOS)，或是colloidal silica；鋁氧化物的來源可以是Catapal Alumina 或 sodium aluminate，但通常這些矽、鋁源價格偏高，製造價格昂貴，導致應用在環境汙染整治方面其實用性不高，主要原因還是歸於成本考量。一般泥渣廢棄物中主要成分為SiO2、Al2O3 組成，萃取其矽源時勢必會有一定量的鋁含量溶出，而這恰好可作為合成含鋁的中孔徑矽基材料之前趨液(precursor solution)使用，同時兼具矽、鋁來源，不必額外添加鋁源。本計畫將嘗試利用污泥及灰渣類等廢棄資源，作為取代合成含鋁的中孔徑矽基分子篩 (Al-MCM-41 和Al-MCM-48)所需的矽、鋁源，並將自製中孔徑材料進行表面官能基改質，開發低成本、高效率多孔性吸附材料，除了能大幅提高本身材料的比表面積與孔體積外，更能提高中孔徑分子篩的純度，未來將應用在吸附去除水體中的重金屬離子(砷酸鹽與鉻酸鹽)，以提高其附加價值性，更能達到廢棄物回收再利用的效果。有鑑於此，本研究特針對此一泥渣廢棄物合成中孔徑多孔吸附材料之開發與應用研究，規劃兩年研究期程，進行開發與探討：第一年「含鋁的中孔徑矽基多孔材料之合成與鑑定」。第二年「含鋁的中孔徑矽基多孔材料其表面改質與吸附毒性氧陰離子之研究」。第一年為「含鋁的中孔徑矽基多孔材料之合成與鑑定」，嘗試利用下水污泥灰、淨水污泥灰或各種水處理污泥灰等廢棄無機資源，萃取其矽、鋁成分以取代傳統昂貴的矽源與鋁源，開發低成本、高純度含鋁的中孔徑矽基多孔材料(Al-MCM-41 和Al-MCM-48)。研究過程將分析不同Si/Al 莫爾比的前趨液對合成含鋁的中孔徑材料其合成條件、表面結構參數與水熱穩定性的變化，探討不同Si/Al 比的污泥灰，鋁含量的多寡，對於合成矽鋁質中孔徑材料的作用與影響。最後將二次回收萃取後殘餘的固體物，使之轉換成微孔沸石吸附劑，以達全資源化效果；第二年為「含鋁的中孔徑矽基多孔材料其表面改質與吸附毒性氧陰離子之研究」，本年度將延續上年度研究建立的基礎下，將自製合成出含鋁的中孔徑矽基多孔材料，以後嫁接(Post-grafting)的修飾方法，進行孔洞表面胺基(Amino group)官能基改質，並評估應用在吸附水中毒性氧陰離子(砷酸鹽和鉻酸鹽)之可行性。 Increasing generation of various sludges, sediments, and inorganic residues such as municipal/industrial incinerator ashes is posing an environmental problem facing society. Traditional treatment of such waste streams includes recycling as roadbed fill, artificial aggregates for concrete, replacements for par tof the raw meal for producing eco-cement, all targeting a recycling-benificial use of the residues to set-off part of the resources depletion problem. The traditional technologies for recycling the above sludges and residues into constructional materials is well developed and have long been practiced; the products, however, have less performance and lack of added value. Therefore, there is possibility to develop novel mesoporous aluminosilicate adsorbents from waste sludge and incinerator residues, that is functional, environmental-friendly, low-cost, and with high added values. The inorganic residues, especially the water-treatment sludge ash, are essentially composed of SiO2, Al2O3 . In addition, most of the mesoporous molecular sieves having been developed thus far are all of aluminosilicates or silicates. In fact, the mesoporous materials can be synthesized using a variety of silicate and aluminate precursors such as fume silica, sodium silicate, tetraethoxysilane, colloidal silica, catapal alumina, and sodium aluminate. However, they are all suffering form high producing costs. Therefore, if waste-derived silica and aluminum sources are used as precursors, this may provide an excellent opportunity to prepare mesoporous aluminosilicate adsorbents economically. This study try to develop a novel synthesis approach for preparing cost-efficient mesoporous aluminosilicate adsorbents from sludge and incinerator residues. The research work is devied into two phases: First year: Development and Application of Mesoporous Aluminosilicate Adsorbents from Waste Sludge and Incinerator Residues(l/2)--Synthesis and Characterization of mesoporous aluminosilicate. Second year: Development and Application of Mesoporous Aluminosilicate Adsorbents from Waste Sludge and Incinerator Residues (2/2)--Surface modification of mesoporous aluminosilicate and its application to toxic oxyanions adsorption. The first year: the study focused on the preparation of a mesoporous aluminosilicate molecular sieves (i.e., Al-MCM-41and Al-MCM-48). The mesoporous molecular sieves are formed by fusion with NaOH with Si and Al species extracted from sludges and incinerator residues as precursors, followed by hydrothermal reaction. The solid residue arising from silica extraction is also simultaneously converted into zeolite adsorbents. The processes conditions and the characteristics of the mesoporous aluminosilicate generated are studied. The second year: based on the results from the first year study, the surface characteristics is modified with organic functional groups such as amino group, to facilitate the removal of arsenate and chromate from wastewater. Effects of modifications on both the pore structure and surface chemistry are studied. The adsorption by the functionalized mesoporous aluminosilicate adsorbents in related to target toxic oxyanions in wastewater are characterized. The preparation of mesoporous aluminosilicate adsorbents using sludge and incinerator residues as starting materials is a novel process, not only cost-effective but also recycling-beneficial. And the wastes-synthesized mesoporous aluminosilicate adsorbents has outperforming characteristics in adsorption and a wide range of potential applications. This study expects the results can be applied to the wastewater treatment process in industries from which sludges can be recycled and synthesized into a high-efficient adsorbent. And again, these functional adsorbents can be applied in the air and water treatment units. This preparation of the functional environmental-purifying composite from waste sludges and incinerator ashes is a novel technology not only recycling oriented, cost-effective but also environmental-benificial. 研究期間：10008 ~ 10107 |
