一般處理砷化鎵研磨廢水須添加大量混凝劑，並且會產生大量污泥，而所添加之混凝劑無法再次利用，因而提高廢水處理成本及環境上之負荷，由於市售的磁性顆粒粒徑較大，單位重量所含的顆粒數較少，基於成本及處理效率的考量，本研究群前期已利用自行製備的氧化鐵奈米顆粒（Fe3O4）。
利用合成的Fe3O4磁性奈米顆粒處理實廠的砷化鎵研磨廢水，以Fe3O4磁性顆粒與研磨廢水中的砷化鎵顆粒於不同的條件下，對濁度及總懸浮固體物去除之影響，如pH值、劑量，且利用Fe3O4顆粒具有磁性的特性，靜置於1000 Gauss外加磁場下以提升處理效率，並利用回收再利用氧化鐵磁性污泥，藉以延長氧化鐵顆粒再處理砷化鎵研磨廢水的能力及減少廢水處理成本。由實驗結果發現，在操作條件控制在pH=7時，濁度及總懸浮固體物去除效率為最佳，可達到98 %，而Fe3O4劑量控制在0.145 g 的Fe3O4量最佳，濁度為2.96 NTU，砷濃度為1 mg/L。以SDS 溶液處理氧化鐵砷化鎵污泥後，可連續處理10次砷化鎵研磨廢水，其濁度為76.5 NTU，SS去除效率95.4 %，累積去除的SS重為5.622 g/L。Fe3O4磁性顆粒操作成本低於混凝處理法，數次Fe3O4磁性顆粒回用分離處理操作成本則可降低至110.5元/m3，低於混凝處理法之操作成本141.3元/m3。
利用磁種凝聚作用將廢水中的砷化鎵顆粒與磁性奈米顆粒(Fe3O4) 碰撞凝聚，不僅只受到重力的沈降，也受到磁力的作用使得去除率提高且沈降也更快速，且投入的氧化鐵顆粒可回收再利用於廢水處理系統中，因此對於砷化鎵研磨廢水的處理，可說是發展了一個操作簡單、快速、減少廢水處理成本及污泥產生量的處理程序。

Magnetic seeding aggregation has been developed to remove GaAs nanoparticles from GaAs grinding wastewaters. Since the number of particles per unit weight of the commercial magnetite is very small due to its large size; therefore, magnetite nanoparticles are required to have efficient removal efficiency of theturbidity. In this study,the recovery of magnetite nanoparticles by different types and concentrations of surfactants.
Synthesized magnetite nanoparticles were then used in the magnetic seeding aggregation of GaAs grinding wastewaters. Influences of solution pH, dasage on the removal efficiency of GaAs nanoparticles were examined, and application of an external magnetic 1000 Gauss field during sedimentation. Experimental results showed that when the solution pH = 7, the removal efficiency of the turbidity is the highest, which is about 98 %, Fe3O4=0.145 g have efficient removal efficiency of theturbidity is 2.96 NTU, As=1 mg/L.
When magnetite-GaAs nanoparticles aggregates settled down in an external magnetic field, besides gravity, they also experienced magnetic forces, which enhance the settling velocity. Hence, high removal efficiency could be achieved in a much shorter time.

[1].陳珮紋，利用 Fe3O4磁性顆粒處理化學機械研磨廢水，中央大學環境工程研究所碩士論文，2004。
[2].F.Ali&A.Gapta,”HEMTs and HBTs: Devices, Fabrication, and Circuits”,1991
[3].劉鎮宗，砷與生態環境的關係，科學月刊，第26 卷，第一期，134-140，1995。
[4].阮國棟，砷之污染特性及處理技術，工業污染防治，第五卷，第二期，156-165，1986。
[5].Sadler, R., H. Olszwy, G. Shaw, and D. D. Connell, Soil and Water Contamination by Arsenic from Atannery Waste, Water Air and Soil Pollutant, Vol.78, pp. 189-198, 1994.
[6].羅新衡、劉婉菁，砷化鎵半導體IC製程含砷廢水處理，第六屆水再生及再利用研討會，59-67，2001。
[7].陳從和，砷之特性及其檢驗處理方法，自來水會刊雜誌，第13卷，105-115，1977。
[8].Ghimire, N. K., Inoue, K., Yamaguchi, H., Makino, K. and Miyajima, T.,“Adsorptive separation of arsenate and arsenite anions from aqueous medium by using orange waste”, Water Res., 37, 4945-4953,2003.
[9].Ferguson, J. F. and Gavis, J.,“A review of the Arsenic Cycle in Natural Waters”, Water Res., 6, 11, 1259-1274,1972.
[10].Gulledge, J. H. and O’Conner, J. T.,Removal of arsenic from water byadsorption on aluminum and ferric hydroxides, JAWWA, 65,8, 548-552, 1973.
[11].O，Connor, J. T.,Removal of trace inorganic constituents by conventionalwater treatment processes, In Proc 16th Water Qual.Conf., 16, 99-110, Univ. of Ill,1974.
[12].Edwards, M., Chemistry of arsenic removal during coagulation and Fe-Mn oxidation, JAWWA, 86, 64-78 ,1994.
[13].葉宣顯、賴文亮，水中砷混凝去除機構之初探，中國環境工程學刊，65-71，1991。
[14].Hering, J.G., Chen, P.Y., Wikie J.A., Elimelech M. and Liang S.,Arsenic removal by ferric chloride , JAWWA, 155-167 ,1996.
[15].Scott, K., Green, J., Do, H. D. and McLean, J. S.,“Arsenic removal by coagulation”, JAWWA, 4, 114-126,1995.
[16].McNeill, S. L. and Edwards, M.,“Aesenic removal during precipitative softening”, J. Environ. Eng., 453-460,1997a.
[17].McNeill, S. L. and Edwards, M.,“Predicting As removal during metal hydroxide precipitation”, JAWWA, 89, 75-86,1997b.
[18].李雅萍，混凝與離子交換法去除水中As (V)之研究，台大環工所碩士論文，1998。
[19].Waypa, J.J. Elimelech, M. and Hering, J.G. Arsenic removeal by RO and NF membranes, JAWWA, 89, 102-114 ,1997.
[20].江謝令涵，以外加電場輔助掃流過濾處理水中砷及天然有機物，台大環工所碩士論文，2002。
[21].Gupta, S.K., Chen, K.Y. Arsenic removal by adsorption, J. Water pollut. Con. Fed. 50, 493-506,1978.
[22].邱誌忠，半導體產業高濃度含砷廢水之處理-化學沈降法與活性炭吸附法之 評估，中興大學環工所碩士論文，2004。
[23].張有義、郭蘭生編譯，膠體及界面化學入門，高立出版社，1997。
[24].Gouy, C., “Suy la Constitution de la Charge Electrique ala Surface Dum Electrolyte,” Annals of Physics, (Pairs)Serie4, 9, pp. 457-468 ,1910.
[25].Chapman, D. L., “A Contribution to the Theory of Electrocapillarity,” Philosophical Magazing, 25, pp. 475-481,1910.
[26].Stern,O.,“Zur Theorie der, Elektrolytischem Doppelschicht”,Acta Electro-chemistry, 30, pp. 508-532, 1924.
[27].蔡騰龍著，工業水處理，正文書局有限公司，2001。
[28].Derjaguin, B. V., L. D. Landau, “Theory of Stability of Strong Charge Lyophobioc Sols and of the Adhesion of Strong Charged Particles in Solutions of Electrolytes”, Acta Physicochimca URSS, 14, pp. 633-662, 1941.
[29].Verwey, E. J., J. Th. G. Overbeek, Theory of the Stability of Lyophobic Colloid, Elsevier, Amsterdam, 1948.
[30].Zhang, X. and R. H. Davis, “The rate of collisions due to Brownian or gravitational motion of small drops,” Journal of Fluid Mechanics, 230, pp. 479–504 ,1991.
[31].Yiacoumi, S., D. Rountree, and C. Tsouris, “Mechanism of Particle Flocculation by Magnetic Seeding,”Journal of Colloid Interface Science, 184, pp. 477-488,1996.
[32].Chin, C. J., S. Yiacoumi, and C. Tsouris, “Shear-Induced Flocculation of Colloidal Particles in Stirred Tanks,”Journal of colloid and interface science, 206, pp. 532-545,1998.
[33].Young, W. D. and D. C. Prieve, “Initial Rate of Flocculation of Magnetic Dispersion in an Applied Magnetic Field,”Industrial and Engineering Chemistry Research, 35, pp. 3186-3194,1996.
[34].謝岱紘，界面活性劑類型與含量對四氯乙烯在氣液間質傳現象影響之探討，高雄第一科大環境與安全衛生系碩士論文，2004。
[35].Hiemenz Paul C., Raj Rajagoplan, Principles of Colloid and Surface Chemistry, 3nd Ed, Marcel Dekker Publisher, New York, 1997.
[36].曹恆光、連大成，淺談微乳液，物理雙月刊，第二十三卷，第四期，pp. 488-493， 2001。
[37].Paria, S., Khilar, K. C,“A review on experimental studies of surfactant adsorption at the hydrophilic solid–water interface ”, Advances in Colloid and Interface Science, 110(3), pp. 75-95, 2004.
[38].王立仁，自磁種凝絮污泥回收再利用奈米磁性顆粒─以化學機械研磨廢水為例，中央大學環境工程研究所碩士論文，2004。
[39].Hu, C. Y., S.L. Lo, C.M. Li and W.H. Kuan, “Treating chemical mechanical polishing (CMP) wastewater by electro-coagulation-flotation process with surfactant ”, Journal of Hazardous Materials , 120(1-3), pp. 15-20, 2005. Engineering B, 118 (1-3), pp. 293-300, 2005.
[40].Weiss, Donald E., Luis O. Kolarik, Anthony J. Priestley, Nevil J. Anderson,“Water clarification”, United States Patent, PAT. NO. 4279756, 1981.
[41].Feng, D., C. Aldrich, H. Tan, “Removal of heavy metal ions by carrier magnetic separation of adsorptive particulates ”, Hydrometallurgy,56(3), pp.359-368, 2000.
[42].Chun, Chan-Lan, Jae-Wood Park, “Oil spill remediation using magnetic separation”, Journal of Environmental Engineering, 127(5), pp. 443-449, 2001.
[43].Sakai, Y., Takahiro Miama and Fujio Takahashi, “Simultaneous removal of organic and nitrogen compounds in intermittently aerated activated sludge process using magnetic separation”, Water Research, 31(8), pp.2113-2116, 1997.
[44].Latour, C. D.,“Magnetic separation in water pollution control”, IEEE Transactions on Magnetics, 9(3), pp. 314-316, 1973.
[45].Latour, C. D., “Magnetic separation in water pollution control - II”, IEEE Transactions on Magnetics , 11(5), pp. 1570-1572, 1975.
[46].Kaminski, M. D., L. Nunez,“Cesium extraction from a novel chemical solvent using magnetic micro-particles”, Separation Science and Technology, 37(16), pp.3703-3714, 2002.
[47].Oliveira, Luiz C. A., Rachel V. R. A. Rios, “Activated carbon/iron oxide magnetic composites for the adsorption of contaminants in water ”, Carbon, 40(12), pp. 2177-2183, 2002.
[48].Oliveira, Luiz C. A., Rachel V. R. A. Rios, “Clay–iron oxide magnetic composites for the adsorption of contaminants in water ”, Applied Clay Science, 22(4), pp.169-177, 2003.
[49].行政院環保署環境檢驗所，水中濁度檢測方法-濁度計法（NIEA W219.51C）
[50].行政院環保署環境檢驗所，水中總溶解固體及總懸浮固體檢測方法-103℃～105℃乾燥（IEA W210.56A）
[51].邱威霖，砷化鎵研磨廢水混凝及其污泥固化處理之研究，元智大學化工碩士論文，2007。
[52].Lai, C. L. and S. H. Lin, “Electrocoagulation of chemical mechanical polishing (CMP) wastewater from semiconductor fabricaton, ”Chemical Engineering Journal, 95, pp. 205–211, 2003.