以電混凝/浮除法收集優養化水體藻類供製生質能之可行性評估

台灣水庫面臨優養化的威脅，已成為水資源利用的隱憂。傳統的去除藻類技術，具有操作和設備成本高、高耗能、控制不易及化學污泥等缺點，近年來電混凝/浮除(ECF)技術被廣泛運用，此技術不但具備固液分離及水質淨化效果且無大量污泥產生問題。回收的藻體富含碳水化合物，是第三代生質能的主要來源，因此本研究以優養化水體為主要標的物，以ECF技術回收微藻及淨化水質，並找出最適操作參數，最後評估回收微藻作為生質能源之潛勢。研究結果顯示，在A及D為最佳操作條件；在水質淨化部分，TP及DOC在A及D條件下具有較明顯的去除效率，然而，這些操作條件對於E. Coli去除的影響並不明顯；藻類生質能潛勢部分，回收的藻類皆殘留43 %以上的金屬；藻類經酸處理後酒精含量為0.38-0.40(g ethanol/g algae)，而鹼處理則為0.06-0.08(g ethanol/g algae)。證實應用電混凝/浮除法於優養化水體回收藻類供製生質能是具可行性的。

關鍵字

電混凝/浮除；生質酒精；微藻；優養化

並列摘要

Lakes and reservoirs in Taiwan are confronted by the threat of eutrophication. It has become the concern of water resources. Technologies of algae removal that have been developed so far have shortcomings of high costs of operating and equipment, high energy consumption, operational difficulties, and chemical sludge. In recent years, electro-coagulation/flotation (ECF) technology is widely used. The technology does not have the problems of solid-liquid separation, water purification and large amounts of sludge. Algae are rich in carbohydrates, which are major soruces of the third generation biofuels. In this study, the water body with eutrophication problems is the main subject matter. We will use ECF technology to recover microalgae from water and remove pollutants and find the optimal operating parameters. Finally, we will assess the potential of producing biofuels from the recovered microalgae. The results show that: the condition of A and D were the best for algae recovery. In the water purification, TP and DOC in the A and D conditions were with obvious removal efficiency .However, the influence of these conditions on the removal of E. Coli/ was unobvious. In the potential of producing biofuels, the recovered microalgae contained more than 43% of the metal. Algae after acid treatment, the bioethanol content was 0.38-0.40 (g ethanol / g algae), and the alkali treatment was 0.06-0.08 (g ethanol / g algae). Confirmed that it was possible to recover algae from eutrophication lakes by electro-coagulation/flotation for biofuel production.