尖晶石結構鐵氧磁體係由三價鐵氧化物與二價金屬氧化物所組成，其中二價金屬（M2+）可由Fe2+、Mg2+、 Ba2+、 Ni2+、Cu2+和Zn2+等金屬互相取代，具有良好耐熱及化學穩定性。因此若能將電鍍污泥等組成複雜之重金屬污泥予以鐵氧磁體化，不僅可有效降低污泥中重金屬移動性，減少重金屬污泥對環境衝擊，更進一步可藉由鐵氧磁體資材化技術提昇重金屬污泥再利用價值。本研究嘗試利用高溫鐵氧磁體法穩定電鍍污泥中重金屬，並檢討燒成物之觸媒特性於類芬頓反應中對反應黑染料（RB5）降解效果。研究中透過XRD晶相分析、燒成物金屬殘留率、燒成物毒性特性溶出試驗（TCLP）以及染料UV分析等試驗，檢討高溫鐵氧磁體化技術應用於電鍍污泥穩定化/資材化之可行性。
以高溫鐵氧磁體法穩定重金屬組成單純之含銅污泥時，控制生料Fe3+/M2+莫耳比大於鐵氧磁體理論合成劑量比2時，高溫鐵氧磁體化形成之CuFe2O4晶相可將銅離子嵌入鐵氧磁體晶格中達穩定化；其最適控制參數為生料Fe3+/Cu2+莫耳比3.5，燒結溫度800˚C下持溫時間大於10小時。針對重金屬組成複雜之含鉻電鍍污泥，直接加熱法可有效穩定污泥中銅與鎳，但熟料中鋅與鉻殘留率低且鉻易於溶出。而以鐵氧磁體法處理含鉻電鍍污泥時，證實可有效穩定污泥中銅、鎳與鋅，並提高熟料中鉻殘留率，但仍無法顯著降低鉻溶出。此外研究亦發現電鍍污泥中Ca(OH)2於高溫下會與Cr2O3形成CaCrO4，導致電鍍污泥中鉻於熱處理後易於溶出。經進一步以活性碳控制高溫鐵氧磁體法於還原氣氛時，證實可有效將污泥中銅、鎳、鋅與鉻皆穩定於熟料中。含鉻電鍍污泥鐵氧磁體化最適參數為生料Fe3+/M2+莫耳比2，添加活性碳5％，於氮氣氣氛燒結溫度800˚C下持溫3小時。
此外經以重金屬化合物配合10％高嶺土，5％聚乙烯醇(PVA)以高溫鐵氧磁體法燒製多孔性鎳鐵氧磁體進行RB5破壞去除。研究證實鎳鐵氧磁體可有效誘發類芬頓反應破壞RB5，且其使用壽命長穩定性甚佳。上述結果證實高溫鐵氧磁體法可將電鍍污泥中之重金屬形成尖晶石結構，有效提高重金屬殘留率降低溶出量，並具有誘發類芬頓反應之材料特性，可達成有害重金屬污泥之穩定化與資材化功效，提昇其利用價值。

Ferrites, known as spinel ferrites, have the general formula of M2+O．Fe23+O3 where M2+ is divalent metallic ion such as Fe2+, Mg2+, Ba2+, Ni2+, Cu2+ and Zn2+. The structure of ferrite is very similar to that of natural mineral, which is thermally and chemically stable. By utilization of plating sludges to synthesize ferrites, the heavy metals in the sludges could be stabilized and the environmental impact of the wastes would also be minimized. The aim of this study is to examine the feasibility of high temperature ferritization on the stabilization of heavy metals in plating sludges, and verify the catalytic effect of sintered specimens in Reactive Black 5 (RB5) degradation. The stabilization of heavy metals in plating sludges by high temperature ferritization is examined using the data obtained from an XRD analysis, the residual ratio of heavy metals in a solid state and the concentration of heavy metals in the Toxicity Characteristic Leaching Procedure (TCLP) leachate.
In terms of copper containing sludges stabilization by high temperature ferritization, copper is stabilized by insertion of copper ion into the stable CuFe2O4 structure. The result indicates that when the Fe3+/M2+ molar ratio of sludges are greater than the stoichiometric ratio of 2, copper ion in sludges would be stabilized hence inhibited Cu leaching. The optimum ferritization parameters are Fe3+/M2+ molar ratio = 3.5, sintering temperature at 800˚C and isothermal time over 10 hours.
The study of chromium containing sludges stabilization was accomplished by different thermal treatments. The results showed that direct thermal treatment facilitates Cu stabilization in plating sludges, but results in low residual ratio of Zn and Cr as well as significant Cr leaching by TCLP. Therefore, high temperature ferritization assists the stabilization of Ni, Cu and Zn, but the TCLP result reveals that it cannot inhibit Cr leaching. Further investigation was conducted to clarify the stability factor of chromium containing sludges during thermal treatment. The results shows that Ca(OH)2 and CaO are easy to react with Cr2O3 to from CaCrO4 thus significantly increase the Cr concentration in TCLP leachate after thermal treatment. Therefore, activated carbon was added in raw modified sludges to enhance reducing atmosphere during high temperature ferritization which effectively facilitates Cr stabilization.
Finally, porous Ni ferrite was synthesized with addition of 5% PVA and 10% kaolinite, which could be utilized to degrade RB5 by Fenton-like reaction. The results show that porous Ni ferrite can effectively degrade RB5, and only minor heavy metal leaching is observed during the process. In summary, high temperature ferritization effectively stabilizes heavy metals in plating sludges and the sintered sludge has the ability to induce Fenton-like reaction. Therefore high temperature ferritization could be applied to hazardous heavy metal sludges stabilization and materialization.

Agrawal, A.; Kumar, V.; and Pandey, B.D., Remediation options for the treatment of electroplating and leather tanning effluent containing chromium - A review. Miner. Process Extr. Metall. Rev., Vol. 27, No. 2, pp. 99-130, 2006.
Ahmed, M.A., Alonso, L., Palacios, J.M., Cilleruelo, C., and Abanades, J.C., Structural changes in zinc ferrites as regenerable sorbents for hot coal gas desulfurization, Solid State Ion., Vol. 138, No. 1-2, pp. 51-62, 2000.
Barth, E.F., An overview of the history, present status, and future direction of solidification/stabilization technologies for hazardous waste treatment, J. Hazard. Mater., Vol. 24, pp. 103-109, 1990.
Box, G.E.P., Hunter, W.G., and Hunter, J.S., Statistics for Experimenters: A Introduction to Design, Data Analysis, and Model Building, John Wiley & Sons, Inc., New York, 1978.
Box, G.E.P., Hunter, W.G., and Hunter, J.S., Statistics for Experimenters: Design, Innovation, and Discovery, second ed., John Wiley & Sons, Inc., Hoboken, NJ, 2005.
Bricka, R.M., Investigation and evaluation of the performance of solidified cellulose and starch xanthate heavy metal sludgess, U.S. army corps of engineers waterway experiment station, technical report EL-88-5, 1998.
Brinker, C.J., and Scherer, G.W., Sol-gel science: the physics and chemistry of sol-gel processing, Academic Press Inc., New York, 1990.
Campbell, S.J., Kaczmarek, W.A., and Wang, G.M., Mechanochemical transformation of hematite to magnetite, Nanostructured Materials, Vol. 6, No. 5-8, pp. 735-738, 1995.
Chen, N.S., Yang, X.J., Liu, E.S., and Huang, J.L., Reducing gas-sensing properties of ferrite compounds MFe2O4 (M=Cu, Zn, Cd and Mg), Sens. Actuators, B Chem., Vol. 66, No. 1, pp. 178-180, 2000.
Chen, P.H., and Watts, R.J., Determination of rates of hydroxyl radical generation in mineral-catelyzed Fenton-like oxidation., Journal of the Chinese Institute of Environmental Eengineering, Vol. 10, pp. 201-208, 2000.
Chen, W.C., A study on the treatment of heavy metal ions by ferrite process, Master thesis on Department of minerals metallurgy and materials science, National Cheng Kung University, 1992.
Cheng, K.Y., Controlling mechanisms of metal release from cement-based waste form in acetic acid solution, Ph.D. Disseration, University of Cincinnati, Cincinnati, OH, 1991.
Chiou, C.S., Chang, C.F., Chang, C.T., Shie, J.L., and Chen, Y.H., Mineralization of Reactive Black 5 in aqueous solution by basic oxygen furnace slag in the presence of hydrogen peroxide, Chemosphere, Vol. 62, pp. 788–795, 2006.
Costa, R.C.C., Lelis, M.F.F., Oliveira, L.C.A., Fabris, J.D., Ardisson, J.D., Rios, R.R. V.A., Silva, C.N., and Lago, R.M., Novel active heterogeneous fenton system based on Fe3-xMxO4 (Fe, Co, Mn, Ni): The role of M2+ species on the reactivity towards H2O2 reaction, J. Hazard. Mater., Vol. 129, No. 1-3, pp. 171-178, 2006.
Cross, W.B., Affleck, L., Kuznetsov, M.V., Parkin, I.P., and Pankhurst, Q.A., Self-propagating high-temperature synthesis of ferrites MFe2O4 (M = Mg, Ba, Co, Ni, Cu, Zn); reactions in an external magnetic field, J. Mater. Chem., Vol. 9, No. 10, pp. 2545-2552, 1999.
Cussler, E., Kopinsky, J., and Weimer, J., The effect of pore diffusion on the dissolution of porous mixtures, Chem. Ene. Sci., Vol. 38, pp. 2027-2033, 1981.
Dennis, J.K., and Such, T.E., Nickel and Chromium Plating, 3rd. Eds. Woodhead Publishing Ltd., pp. 205–240, 1996.
Faungnawakij, K., Kikuchi, R., Fukunaga, T., and Eguchi, K., Catalytic hydrogen production from dimethyl ether over CuFe2O4 spinel-based composites: Hydrogen reduction and metal dopant effects, Catal. Today, Vol. 138, No. 3-4, pp. 157-161, 2008.
Faungnawakij, K., Kikuchi, R., Fukunaga, T., and Eguchi, K., Catalytic hydrogen production from dimethyl ether over CuFe2O4 spinel-based composites: Hydrogen reduction and metal dopant effects, Catal. Today, Vol. 138, pp. 157-161, 2008.
Fukumasa, O. and Fujiwara, T., Rapid synthesis of ferrite particles from powder mixtures using thermal plasma processing, Thin Solid Films, Vol. 435, pp. 33-38, 2003.
Goldman, A., Modern Ferrite Technology, 2nd. Ed. Springer, pp. 51-60, 2006.
Hsueh, C.L., Huang, Y.H., Wang, C.C., and Chen, C.Y., Degradation of azo dyes using low iron concentration of Fenton and Fenton-like system, Chemosphere, Vol. 58, pp. 1409–1414, 2005.
Hu, J., C., I.M. and Chen, G., Removal Cr(VI) by magnetite nanoparticles, Water Sci. Technol., Vol. 150, No. 12, pp. 139-146, 2004.
Hu, S.H., Tsai, M.S., Yen, F.S., and Onlin, T., Recovery of copper-contaminated sludges in a two-stage leaching process, Environ. Prog., Vol. 25, No. 1, pp. 72-78, 2006.
Illés, E., Tombácz, E., The effect of humic acid adsorption on pH-dependent surface charging and aggregation of magnetite nanoparticles, J. Coll. Int. Sci., Vol. 295, pp. 115-123, 2006.
Illés, E., Tombácz, E., The role of variable surface charge and surface complexation in the adsorption of humic acid on magnetite, Colloids and Surfaces. A, Physicochemical and Engineering Aspects, Vol. 230, pp. 99-109, 2004.
James, M.G., Beattie, J.K., and Kennedy, B.J., Recovery of chromate from plating sludges, Waste Manage and Research, Vol. 18, No. 4, pp. 380-385, 2000.
Janghorban, K., and Shokrollahi, H., Influence of V2O5 addition on the grain growth and magnetic properties of Mn-Zn high permeability ferrites, J. Magn. Magn. Mater., Vol. 308, pp. 238-242, 2007.
Kakarla, K.C., and Watts, R.J., Depth of Fenton-like oxidation in remediation of surface soil, Journal of Environmental Engineering, Vol. 123, pp. 11-17, 1997.
Karapinar, N., Magnetic separation of ferrihydrite from wastewater by magnetic seeding and high-gradient magnetic separation, Int. J. Miner. Process, Vol. 71, pp. 45-54, 2003.
Kato, I., and Nagai, S., Treatment of chromium containing wastewater, Jpn. Kokai Tokkyo Koho JP, 03224691, 1991.
Kim, Y.K., and Huh, I.R., Enhancing biological treatability of landfill leachate by chemical oxidation, Environ. Eng. Sci., Vol. 14, No. 1, pp. 73-79, 1997.
Kirk, D.W., Chan, C.C.Y., and Marsh, H., Chromium behavior during thermal treatment of MSW fly ash, J. Hazard. Mater., Vol. 90, No. 1, pp. 39-49, 2002.
Kitis, M., Adams, C.D., and Daigger, G.T., The Effects of Fenton’s reagent pretreatment on the biodegradability of nonionic surfactants, Water Res., Vol. 33, No. 11, pp. 2561-2568, 1999.
Li, P., Yu, Bo. and Wei, X., Synthesis and characterization of a high oil-absorbing magnetic composite material, J. Appl. Polym. Sci., Vol. 93, pp. 894-900, 2004.
Lin, T.T., Reaction Mechanisms and Leaching Behaviors of CuO Solidified/ Stabilized with Cement, Ph.D. thesis on Graduate Institute of Environmental Engineering, National Taiwan University, 1993.
Lorentzou, S., Karadimitra, K., Agrafiotis, C., and Konstandopoulos, A.G., New routes for ferrite powders synthesis, PARTEC, International Conference for Particle Technology, Nuremberg, Germany, 2004.
Marco, S., Lucas, and Jose’ A. Peres, Decolorization of the azo dye Reactive Black 5 by Fenton and photo-Fenton oxidation, Dyes and Pigments, Vol. 71, pp. 236-244, 2006.
McCurrie, R.A., Ferromagnetic Materials: structure and properties, Academic Press Inc., New York, 1994.
Mohai, I., Szépvölgyi, J., Bertóti, I., Mohai, M., Gubicza, J. and Ungár T., Thermal plasma synthesis of zinc ferrite nanopowders, Solid State Ionics, Vol. 141-142, pp. 163-168, 2001.
Montanaro, L., Bianchini, N., Rincon, J.M., and Romero, M., Sintering behaviour of pressed red mud wastes from zinc hydrometallurgy, Ceram. Int., Vol. 27, No. 1, pp. 29-37, 2001.
Nakamura, T., Okano, Y., and Miura, S., Interfacial diffusion between Ni-Zn-Cu ferrite and Ag during sintering, J. Mater. Sci., Vol. 33, No. 4, pp. 1091-1094, 1998.
Okuda, T., Removal of heavy metals from wastewater by ferrite co-precipitation, Filtr. Sep., Vol. 12, No. 5, pp. 472-478, 1975.
Peng, X., Luan, Z. and Zhang H., Montmorillonite-Cu(Ⅱ)/Fe(Ⅲ) oxides magnetic material as adsorbent for removal of humic acid and its thermal regeneration, Chemosphere, vol. 63, pp. 300-306, 2006.
Qu, J.H., Research progress of novel adsorption processed in water purification: A review, J. Environ. Sci, Vol. 20, No. 1, pp. 1-13, 2008.
Rahaman, M.N., and Jonghe, L.C., Reaction sintering of zinc ferrite during constant rates of heating, J. Am. Chem. Soc., Vol. 76, No. 7, pp. 1739-1744, 1993.
Rahman, I.Z., and Ahmed, T.T., A study on Cu substituted chemically processed Ni-Zn-Cu ferrites, J. Magn. Magn. Mater., No. 290-291, pp. 1576-1579, 2005.
Renard, D.E., Metal recovery from leached plating sludge, Plat. Surf. Finish., Vol. 74, No. 10, pp. 46-48, 1987.
Rezlescu, R., Doroftei, C., Rezlescu, E., and Popa, P.D., Lithium ferrite for gas sensing applications, Sens. Actuators B: Chem., Vol. 133, No. 2, pp. 420-425, 2008.
Ristic, M., Hannoyer,B., Popovic, S., Music, S., and Bajraktaraj, N., Ferritization of copper ions in the Cu–Fe–O system, Mater. Sci. Eng. B Solid State Adv. Technol., Vol. 77, No. 1, pp. 73-82, 2000.
Roy, C.H., Wastewater control and treatment, in: Durney L.J. (Ed.), Electroplating engineering handbook, 4th. Ed. England: Chapman & Hall, pp. 212–215, 1996.
Saxena, N.K., Kumar, N., and Pourush, P.K.S., Study of LiTiMg-ferrite radome for the application satellite communication. J. Magn. Magn. Mater., Vol. 322, No. 18, pp. 2641-2646, 2010.
Schrank, S.G., José, H.J., Moreira, R.F.P.M., and Schröder, H.F.r., Applicability of fenton and H2O2/UV reactions in the treatment of tannery wastewaters, Chemosphere, Vol. 60, No. 5, pp. 644-655, 2005.
Selvan, R.K., Augustin, C.O., Berchmans, L.J ., and Saraswathi, R., Combustion synthesis of CuFe2O4, Mater. Res. Bull., Vol. 38, No. 1, pp. 41-54, 2003.
Seo, S.H., and Oh, J.H., Effect of MoO3 addition on sintering behaviors and magnetic properties of NiCuZn ferrite for multilayer chip inductor, IEEE Trans. Magn., Vol. 35, No. 5, pp. 3412-3414, 1999.
Snyder, R.L., The use of reference intensity ratios in X-ray quantitative analysis, Powder Diffr., Vol. 7, No. 4, pp. 186-193, 1992.
Sylvester, P., Rutherford, L. A., JR., Gonzalez-Martin, A., and Kim, J., Ferrite treatment for removing chromium from high-level radioactive tank waste, Environ. Sci. Technol., Vol. 35, pp. 216-221, 2001.
Tamaura, Y., Katsura, T., Rojarayanont, S., Yoshida, T., and Abe, H., Ferrite process. Heavy metal ions treatment system, Water Sci. Technol., Vol. 23, No. 10-12, pp. 1893-1900, 1991.
Tamaura, Y., Tu, P.Q., Rojarayanont, S., and Abe, H., Stabilization of hazardous materials into ferrites, Water Sci. Technol., Vol. 23, No. 1-3, pp. 399-404, 1991.
Tiravanti, G., Petruzzelli, D., and Passino, R., Low and non waste technologies formetals recovery by reactive polymers, Waste Management, Vol. 16, No. 7, pp. 597-605, 1996.
Tsuji, M., Kodama, T., Yoshida, T., Kitayama, Y., and Tamaura, Y., Preparation and CO2 methanation activity of an ultrafine Ni(Ⅱ) ferrite catalyst, J. Catal., Vol. 164, pp. 315-321, 1996.
U.S. EPA., Stabilization/Solidification of CERCLA and RCRA wastes, physical tests, chemical testing procedures, technology screening, and field activities, EPA/625/6-89/022, Office of Research and Development, Washington, D.C., 1989.
USEPA (1998). Permeable reactive barrier technologies for contaminant remediation. EPA/600/R-98/125. Http://www.epa.gov/nrmrl/pubs/600R98125/reactbar.pdf. Accessed the 9th of February 2010.
Valdés-Solís, T., Valle-Vigón, P., Álvarez, S., Marbán, G., and Fuertes, A.B., Manganese ferrite nanoparticles synthesized through a nanocasting route as a highly active Fenton catalyst, Catal. Commun., Vol. 8, pp. 2037-2042, 2007.
Wang, Y., Linag, Z., Yuan, X., and Xu, Y., Preparation of cellular iron using wastes and its application in dyeing wastewater treatment, J. Porous Mater., Vol. 12, pp. 225-232, 2005.
Windholz, M., Budavari, D., Stroumtsos, L. Y., and Fertig, M. N., The Merck Index, 9th. Eds. Merck & Co., Inc, Rahway, New Jersey, 1976.
Xu, X.R., Li, H.B., Wang, W.H., and Gu, J.D., Degradation of dyes in aqueous solutions by the fenton process, Chemosphere, Vol. 57, No. 7, pp. 595-600, 2004.
Yamamoto, H., Uchida, K., Kaneko, T., and Kami, Y., Noise filter using a transmission line formed in lossy ferrite medium, Electron. Comm., Jpn. 1 Vol. 87, No. 10, pp. 1-9, 2004.
Zhang L., Su, M., and Guo, X., Studies on the treatment of brilliant green solution of combination microwave induced oxidation with CoFe2O4, Sep. Purif. Technol., Vol. 62, pp. 458-463, 2008.