改善水質優養的方法很多，其中在水庫內浮除去藻是一種直接有效的方法，但影響浮除法效果因素很多，有浮除時間、pH值、混凝劑/助凝劑及氣固比 (A/S) 等，本研究以金門太湖為對象，研究各種浮除條件對葉綠素-a及磷的去除效果。
本研究以明礬與多元氯化鋁 (PAC) 為混凝劑，並以幾丁聚醣 (Chitosan) 及聚二甲基二烯丙基氯化銨 (PDMDAC) 為助凝劑。PAC最佳pH為5.8，A/S=0.147，浮除時間3分鐘下之最佳加藥量為30 mg/L，其葉綠素-a及正磷、總磷之去除率分別為90.2 %、75.79 %和31.2 %；若添加0.1 mg/L 之PDMDAC及0.3 mg/L之幾丁聚醣，其最佳加藥量可降至25 mg/L，兩者對葉綠素-a及正磷之去除率效果相近，但對總磷去除率前者較後者佳；另一種混凝劑之明礬，在最佳pH=5.8，A/S=0.478，浮除時間為3分鐘下，最佳加藥量為40 mg/L，對葉綠素-a及正磷、總磷去除率依次為87.5 %、94.2 %和76.5 %。若再加0.1 mg/L之 PDMDAC及3 mg/之幾丁聚醣，其最佳加藥量可降至25mg/L及10 mg/L。兩者對葉綠素-a及正磷去除率效果相似，但對總磷之去除率還是以添加PDMDAC效果較為顯著。
將去除效率換算成去除1 kg葉綠素-a所需處理成本，結果顯示，以明礬25 mg/L加PDMDAC 0.1 mg/L的成本最低，每kg約1,350元。其次是PAC 25 mg/L加PDMDAC 0.1 mg/L，處理成本每kg約1,950元。而最貴的是明礬10 mg/L加幾丁聚醣3 mg/L，約每kg約39,651元。

This study is aimed at using dissolved air flotation (DAF) process in laboratory to purify lake water sampled from an eutrophicated reservoir with frequent algal-bloom events. DAF is one of the most effective methods for not only algae but also phosphorus removal, which are the most important components of eutrophication index. Four primary factors related to the efficiency of chlorophyll-a (chl-a) and phosphorus removal were discussed in this study, including flotation time, pH value, air to solid ratio (A/S) and coagulant/coagulation-aids.
Two common coagulants for traditional water treatment were test, e.g., aluminum sulfate (AS) and poly-aluminum chloride (PAC). Additionally, two advanced polymer, e.g., Chitosan and Poly-dially-dimethy-ammomium-chloride (PDMDAC), are selected as coagulation-aids to test their extra values for DAF. The best pH value, A/S, and flotation time for PAC is 5.8, 0.147, and 3 minutes, respectively. Under the optimum settings and a dosage of 30 mg/L PAC, the removal efficiency for chl-a, PO43--P and total phosphorous (TP) is 90 %, 76 % and 31 %, respectively. The dosage of PAC can be reduced to 25 mg/L if 0.1 mg/L PDMDAC or 0.3 mg/L Chitosan is added. The performance of chl-a and PO43--P removal for PAC-PDMDAC and PAC-Chitosan is similar, but PAC-PDMDAC has higher efficiency (90 % to 76 %) for the removal of TP. Follow the same procedures of PAC test, the optimum settings for AS as coagulant is the same as PAC except for the much higher A/S value, 0.478. The removal efficiency for chl-a, PO43--P and TP is respectively 88 %, 94 % and 77 % when the AS dosage is 40 mg/L. The dosage of AS can be reduced to 25 mg/L (0.1 mg/L PDMAC as coagulation-aids) and 10 mg/L (3 mg/L Chitosan as coagulation-aids). The performance of chl-a and PO43--P removal for AS-PDMDAC and AS-Chitosan is similar, but the AS-PDMDAC has higher efficiency (94 % to 72 %) for the removal of TP.
Due to the relative high price of Chitosan, the unit cost of 1 kg chl-a removal for AS-PDMDAC, PAC-PDMDAC and AS-Chitosan is NT 1,350, NT 1,872 and NT 39,651, respectively. Therefore, we suggest AS-PDMDAC as the better coagulant/coagulation-aids in the treatment of Lake Tai water using in-situ DAF process.

[1]. Amirtharagjah, A. and O'Melia, C. R. “Chap 6: Coagulation and Flocculation (Vol. 6.1.)”: Water Quality and Treatmant. 5th. AWWA. (1990).
[2]. Amirthrajah, A. and Mills, K. M. “Rapid Mix Design for Mechanism of Alum Coagulation.” Journal of the American Water Works Association 74(4), 210-216. (1982).
[3]. AWWARF and IWSA. “Treatment Process Selection for Particle Removal”. Denver, Colorado: American Water Works Association. (1998).
[4]. Caceres, L. and Contreras, R. “Municipal wastewater treatment by lime/ferrous sulfate and dissolved air flotation.” Water Science and Technology, 31(3), 285-294. (1995).
[5]. Chen, Y. M., Liu, J. C. and Ju, Y. H. “Flotation removal of algae from water.” Colloids and Surfaces, 12, 49-55. (1998).
[6]. Chin, K. K. “Evaluation of Treatment Efficiency of Process for Petroleum Refinery Wastewater.” Water Science and Technology, 29(8), 47-50. (1994).
[7]. Chorus, I., Falconer, I. R., Salas, H. J. and Bartram, J. “Health risks caused by freshwater cyanobacteria in recreational waters.” Journal of Toxicology and Environmental Health, Part B, 3, 323-347. (2000).
[8]. Chung, T. H. and Kim, D. T. “Significance of Pressure and Recirculation in Sludge Thickening by Dissolved Air Flotation.” Water Science and Technology, 36(12), 223-230. (1997).
[9]. Craenenbroeck, W. V., Bogaert, J. V. D. and Ceulemans, J. “The Use of Dissolved Air Flotation for the Removal of Algae - the Antwerp Experience.” Water Supply, 11, 123-133. (1993).
[10]. Donigian, A. S. J. and Crawford, N. H. “Modeling Nonpoint Pollution from the Land Surface.” Athens, GA, EPA. (1976).
[11]. Edzwald, J. K. “Algae, bubble, coagulant, and dissolved air flotation.” Water Science and Technology, 27(10), 67-81. (1993).
[12]. Edzwald, J. K. “Principle and application of dissolved air flotation.” Water Science and Technology, 31(3-4), 1-23. (1995).
[13]. Edzwald, J. K. and Walsh, J. P. “Dissolved air flotation: Laboratory and pilot investigation.” American Water Works Association research foundation and American Water Works Association. Dnever. (1992)
[14]. Edzwald, J. K., Walsh, J. P., Kaminski, G. S. and Dunn, H. J. “Flocculation and air requirements for dissolved air flotation.” Journal of the American Water Works Association, 84(3), 92-100. (1992)
[15]. Falconer, I. R. “Potential impact on human health of toxic cyanobacteria.” Phycologia, 35, 6-11. (1996).
[16]. Ferguson, C., Logsdon, G. S. and D. Curley. “Comparison of Dissolved Air Flotation and Direct Filtration.” Water Science and Technology, 31(3-4), 113-124. (1995).
[17]. Fukushi, K., Tambo, N. and Matsui, Y. “A kinetic model for dissolved air flotation in water and wastewater treatment.” Water Science and Technology, 31(3), 37-47. (1995).
[18]. Han, M. and Dockko, S. “Zeta Potential Measurement of Bubbles in DAF Process and Its Effect on the Removal Efficiency.” KSCE Journal of Civil Engineering, 2(4), 461-466. (1998).
[19]. Heinanen, J., Jokela, P. and Peijari, T. A. “Use of Dissolved Air Flotation in Potable Water Treatment in Finland.” Water Science and Technology, 31(3-4), 225-238. (1995).
[20]. Janssens, J. G. “Developments in Coagulation, Flocculation and Dissolved Air Flotation.” Water Engineering and Management, 139(1), 26-31. (1992).
[21]. Johnson, B. A., Gong, B., Bellamy, W. and Tran, T. “Pilot plant testing of dissolved air flotation for treating Boston's low-turbidity surface water supply.” Water Science and Technology, 31(3-4), 83-92. (1995).
[22]. Knorr, D. “Dye Binding Properties of Chitin and Chitosan.” Journal of Food Science, 48(1), 36-37. (1983).
[23]. Koutlemani, M. M., Mavros, P. and Zouboulis, A. I. “Recovery of Co2加 Ions from Aqueous Solution by Froth Flotation. PartⅡ . CoS Precipitation.” Separation Science and Techonology, 30(2), 263-284. (1995).
[24]. Letterman, R. D. and Pero, R. W. “Contaminants in Polyelectrolytes used in water treatment.” Journal of the American Water Works Association, 82(11), 87-97. (1990)
[25]. Malley, J. P. “The use of selective and direct DAF for removal of particulate contaminants in drinking water treatment.” Water Science and Technology, 31(3), 49-57. (1995).
[26]. Malley, J. P. Jr. and Edzwald, J. K. “Laboratory comparison of DAF with conventional treatment.” Journal of American water works association, 83(9), 56-61. (1991)
[27]. Matis, K. A. and Mavros, P. “Recovery of Metals by Ion Flotation from Dilute Aqueous Solutions.” Separation and Purification Methods, 20(1), 1-48. (1991).
[28]. Matsui, Y., Fukushi, K. and Tambo, N. “Modeling, simulation and operational parameters of dissolved air flotation.” Journal of Water Supply Research and Technology-Aqua, 47(1), 9-20. (1998).
[29]. M'Bareck, C. O., Metayer, M. and Labbe, M. “Interpolymer associations between poly(vinyl alcohol) and poly(diallyldimethylammonium chloride) in aqueous dilute solution.” Journal of Applied Polymer Science, 86(2), 433-435. (2002).
[30]. McGarry, M. G. “Algal Folcculation with Aluminum Sulfate and Polyelectrolytes.” Journal WPCF, 42(5), 191-201. (1970).
[31]. Muchmore, C. B. “Algae control in water-supply reservoirs.” Journal of American water works association, 70(5), 273-279. (1978).
[32]. O’Melia, C. R. “Coagulation and Flocculation.” (1972).
[33]. Offringa, G. “Dissolved Air Flotation in Southern Africa.” Water Science and Technology, 31(3-4), 159-172. (1995).
[34]. Rilyov, N. N. “Application of ultra-flocculation and turbulent micro-flotation to the removal of fine contaminants from water.” Colloids and Surfaces A: Physicochemical and Engineering Aspects, 151(1-2), 283-291. (1999).
[35]. Robarts, R. D. and Zohary, T. “Temperature effects on photosynthetic capacity, respiration, and growth rates of bloom-forming cyanobacteria.” New Zealand Journal of. Marine and Freshwater Research 21, 391-399. (1987)
[36]. Saffermar, R. and Bernstei, I. “Clinical sensitivity to green-algae demonstrated by nasal challenge and in vitro tests of immediate hypersensitivity.” J Allergy Clin Immunol, 51(7), 22-28. (1973).
[37]. Schneider, I. A., Neto, V. M., Soares, A., Rech, R. L. and Rubio, J. “Primary treatment of a Soybean protein bearing effluence by dissolved air flotation and by sedimentation.” Water Research, 29(1), 69-75. (1995)
[38]. Schneider, O. D., Nickols, D. and Lehan, E. R. “Dissolved Air Flotation and Polyaluminum Chloride – An Effective, Economical Combination.” Proceedings of the Annual AWWA Conference – Water Research for the New Decade, Philadelphia, PA, USA,, 367-383. (1991).
[39]. Schofield, T. “Birmingham Frankley water treatment works redevelopment.” Water Science and Technology, 31(3), 213-223. (1995).
[40]. Schubert, H. “On the turbulence-controlled microprocesses in flotation machines.” International Journal of Mineral Processing, 56(1-4), 257-276. (1999).
[41]. Teseng, S. K. and Liu, C. J. “Removal of Algae from Water by Dissolved Air Flotation.” Journal of Chineses Institute of Environmental Engineering, 6(1), 71-76. (1996).
[42]. Tilton, R. C. and Murphy, J. “The Flocculation of Algae with Synthetic Polymeric Flocculants.” Wat. Res, 6(155-164). (1972).
[43]. Viitasaari, M., Jokela, P. and Heinanen, J. “Dissolved Air Flotation in the Treament of Industrial Wastewaters with a Special Emphasis on Forest and Foodstuff Industries.” Water Science and Technology, 31(3-4), 299-313. (1995).
[44]. Zouboulis, A. I. and Matis, K. A. “Removal of Cadmium from Dilute Solutionby Flotation.” Water Science and Technology, 31(3-4), 315-326. (1995).
[45]. Zabel, T. “The advantages of dissolved-air-flotation for water treatment.” Journal of American water works association, 77(5), 42-46. (1985).
[46]. 王任芳、周珊珊、李克華、董漢平、黃連華和嚴忠，”聚二甲基二烯丙基氯化銨的合成及絮凝性能研究”。長江大學，3(3)，44-47。(2006)
[47]. 台灣自來水公司，”高濁度原水處理現況與展望”。(2005)
[48]. 行政院環境保護署，”飲用水水源及水質中產毒藻種及藻類毒素之研究（第三年）期末報告”。(2007)
[49]. 江晃榮，”幾丁質與幾丁聚醣產業現況與展望”。財團法人生物技術開發中心。(1996)
[50]. 吳俊宗，”藻類與金沙地區自來水水質關係之探討”。中央研究院植物所。(2004b)
[51]. 李勳宜，”草蝦幾丁質之製備及其應用研究”。國立台灣大學食品科技研究所。碩士：104.。(1988)
[52]. 林俊煌，”不同去乙醯度之幾丁聚醣流變性質與鏈柔軟度、膜之物理特性的關係”。國立台灣海洋大學水產食品科學研究所。碩士：116。(1991)
[53]. 金門縣自來水廠，”飲用水湖庫水體水質改善實場-實場效能測試試驗計畫”。(2005)
[54]. 金門縣政府，From: http://www.kinmen.gov.tw
[55]. 株式会社イガデン，”湖沼水淨化處理裝置”。From: http://www.igaden.com/Lake.htm, 1-5。(2006)
[56]. 高嘉宏，”化學混凝程序去除水中腐植酸之研究”。大葉大學環境工程學系。碩士：128。(2002)
[57]. 郭振泰等，”以生態工法淨化水庫水質控制優養化研究計畫”，行政院環保署。(2005)
[58]. 張志杰和賴發英，”聚二甲基二烯丙基氯化銨對景觀水處理的影響”。安徽農業科學，35(31)，9910-9912。(2007)
[59]. 連啟祥，”以溶解空氣浮除法做為工業廢水前處理之研究”。國立台灣科技大學化學工程系。碩士：110。(1999)
[60]. 溫清光，”金門太湖、榮湖水庫污染整治規劃與初步設計計畫”。金門縣環境保護局。(2008)
[61]. 趙華章、高寶玉和岳欽豔，”二甲基二烯丙基氯化銨(DMDAAC)聚合物的研究進展”。數學化期刊，19(6)。(1999)
[62]. 蔡利局，”混凝沉澱及浮除法去除水中藻類之研究”。國立台灣大學環境工程學研究所。碩士：163。(1988)
[63]. 劉嘉宏，”混凝劑種類對低濁度原水混凝影響之研究”。國立成功大學環境工程學系。碩士：116。(2007)
[64]. 歐陽嶠暉，”下水道工程學”。長松文化公司出版。(2003)
[65]. 蘇郁婷，”微囊藻毒素在淨水處理程序流佈之研究”。國立成功大學環境工程學系。碩士：131。(2005)