Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/5733
標題: pH對過硫酸鹽氧化甲基藍影響之反應動力探討
pH effect on the reaction kinetics of persulfate oxidation of methylene blue
作者: 黃順欽
Huang, Shun-Chin
關鍵字: persulfate
過硫酸鹽
sulfate radical
hydroxyl radical
thermal activation
kinetics
硫酸根自由基
氫氧根自由基
熱活化
反應動力
出版社: 環境工程學系所
引用: Afkhami, A., Mosaed, F., 2002. Catalytic-spectrophotometric determination of trace amounts of oxalate by methylene blue-dichromate redox reaction. Canadian Journal of Analytical Sciences and Spectroscopy 47, 55-59. Aldrich-Chemicals, 1996. Aldrich Handbooks of Dyes and Strains. Alexander, A., Eli, K., Emanuel, M., 2001. Solubilities and vapour pressures of saturated aqueous solutions of sodium peroxydisulfate and potassium peroxydisulfate. Journal of Chemical Thermodynamics 33, 61-69. An, T.-C., Zhu, X.-H., Xiong, Y., 2002. Feasibility study of photoelectrochemical degradation of methylene blue with three-dimensional electrode-photocatalytic reactor. Chemosphere 46, 897-903. Andreottola, G., Bonomo, L., De Gioannis, G., Ferrarese, E., Muntoni, A., Polettini, A., Pomi, R., Saponaro, S., 2010. Lab-scale feasibility tests for sediment treatment using different physico-chemical techniques. Journal of Soils and Sediments 10, 142-150. Anipsitakis, G.P., Dionysiou, D.D., 2004. Radical generation by the interaction of transition metals with common oxidants. Environmental Science & Technology 38, 3705-3712. Banat, F., Al-Asheh, S., Al-Rawashdeh, M.m., Nusair, M., 2005. Photodegradation of methylene blue dye by the UV/H2O2 and UV/acetone oxidation processes. Desalination 181, 225-232. Behrman, E.J., Dean, D.H., 1999. Sodium peroxydisulfate is a stable and cheap substitute for ammonium peroxydisulfate (persulfate) in polyacrylamide gel electrophoresis. Journal of Chromatography B: Biomedical Sciences and Applications 723, 325-326. Bhattacharyya, K.G., Sharma, A., 2005. Kinetics and thermodynamics of methylene blue adsorption on neem (azadirachta indica) leaf powder. Dyes and Pigments 65, 51-59. Bougie, S., Dube, J.S., 2007. Oxidation of dichlorobenzene isomers with the help of thermally activated sodium persulfate. Journal of Environmental Engineering & Science 6, 397-407. Brooks, M.M., 1936. Methylene blue as an antidote for cyanide and carbon monoxide poisoning. The Scientific Monthly 43, 585-586. Buchholz, K., Schirmer, R.H., Eubel, J.K., Akoachere, M.B., Dandekar, T., Becker, K., Gromer, S., 2008. Interactions of methylene blue with human disulfide reductases and their orthologues from plasmodium falciparum. Antimicrobial Agents and Chemotherapy 52, 183-191. Buxton, G.V., Greenstock, C.L., Helman, W.P., Ross, A.B., 1988. Critical review of rate constants for reactions of hydrated electrons, hydrogen atoms and hydroxyl radicals (‧OH/‧O - ) in aqueous solution. Journal of Physical and Chemical Reference Data 17, 513-886. Buxton, G.V., Salmon, G.A., Wood, N.D., 1990. A pulse radiolysis study of the chemistry of oxysulfur radicals in aqueous solution. In: Restelli, G., Angeletti, G. (Eds.). Proceedings of the Fifth European Symposium: Physico-Chemical Behaviour of Atmospheric Pollutants. Kluwer, Dordrecht, Netherlands, pp. 245-250. Chang, C.-Y., Hsieh, Y.-H., Hsieh, L.-L., Yao, K.-S., Cheng, T.-C., 2009. Establishment of activity indicator of TiO2 photocatalytic reaction--Hydroxyl radical trapping method. Journal of Hazardous Materials 166, 897-903. Chawla, O.P., Fessenden, R.W., 1975. Electron spin resonance and pulse radiolysis studies of some reactions of peroxysulfate (SO4-‧). Journal of Physical Chemistry 79, 2693-2700. Chen, K.F., Kao, C.M., Wu, L.C., Surampalli, R.Y., Liang, S.H., 2009. Methyl tert-butyl ether (MTBE) degradation by ferrous ion-activated persulfate oxidation: Feasibility and kinetics studies. Water Environment Research 81, 687-694. Chen, X., Qiao, X., Wang, D., Lin, J., Chen, J., 2007. Kinetics of oxidative decolorization and mineralization of Acid Orange 7 by dark and photoassisted Co2+-catalyzed peroxymonosulfate system. Chemosphere 67, 802-808. Christodoulatos, C., Koutsospyros, A.D., Brodman, B.W., Korfiatis, G.P., 1997. Biodegradation of diphenylamine by selected microbial cultures. Journal of Environmental Science and Health. Part A: Environmental Science and Engineering and Toxicology 32, 15-30. Chu, W., Ma, C.W., 1998. Reaction kinetics of UV-decolourization for dye materials. Chemosphere 37, 961-974. Clesceri, L.S., Greenberg, A.E., Eaton, A.D., 1998. Standard methods for the examination of water and wastewater, 20th ed. APHA, AWWA, WEF, Washington, DC, USA. Costa, C., Santos, V.H.S., Araujo, P.H.H., Sayer, C., Santos, A.F., Fortuny, M., 2009. Microwave-assisted rapid decomposition of persulfate. European Polymer Journal 45, 2011-2016. Criquet, J., Leitner, N.K.V., 2009. Degradation of acetic acid with sulfate radical generated by persulfate ions photolysis. Chemosphere 77, 194-200. David Gara, P.M., Bucharsky, E., Wörner, M., Braun, A.M., Mátire, D.O., Gonzalez, M.C., 2007. Trichloroacetic acid dehalogenation by reductive radicals. Inorganica Chimica Acta 360, 1209-1216. De, A.K., Chaudhuri, B., Bhattacharjee, S., Dutta, B.K., 1999. Estimation of ‧OH radical reaction rate constants for phenol and chlorinated phenols using UV/H2O2 photo-oxidation. Journal of Hazardous Materials 64, 91-104. Dogliotti, L., Hayon, E., 1967. Flash photolysis of per[oxydi]sulfate ions in aqueous solutions. The sulfate and ozonide radical anions. Journal of Physical Chemistry 71, 2511-2516. Dutta, K., Mukhopadhyay, S., Bhattacharjee, S., Chaudhuri, B., 2001. Chemical oxidation of methylene blue using a Fenton-like reaction. Journal of Hazardous Materials 84, 57-71. Eberson, L., 1987. Electron Transfer Reactions in Organic Chemistry. Springer-Verlag, Berlin. Edwards, J.O., 1980. Thermal decomposition of peroxodisulphate ions. Reviews in Inorganic Chemistry 2, 179-206. FMC-Corporation, 2001. Persulfate technical information http://www.fmcchemicals.com/TechDataSheetsMSDS/Persulfates.aspx. Gayathri, P., Praveena Juliya Dorathi, R., Palanivelu, K., 2010. Sonochemical degradation of textile dyes in aqueous solution using sulphate radicals activated by immobilized cobalt ions. Ultrasonics Sonochemistry 17, 566-571. Gimenez, J., Curc, D., Marco, P., 1997. Reactor modelling in the photocatalytic oxidation of wastewater. Water Science and Technology 35, 207-213. Goulden, P.D., Anthony, D.H.J., 1978. Kinetics of uncatalyzed peroxydisulfate oxidation of organic material in fresh water. Analytical Chemistry 50, 953-958. Hayon, E., McGarvey, J.J., 1967. Flash photolysis in the vacuum ultraviolet region of sulfate, carbonate, and hydroxyl ions in aqueous solutions. Journal of Physical Chemistry 71, 1472-1477. Hayon, E., Treinin, A., Wilf, J., 1972. Electronic spectra, photochemistry, and autoxidation mechanism of the sulfite-bisulfite-pyrosulfite systems. SO2-, SO3-, SO4-, and SO5- radicals. Journal of the American Chemical Society 94, 47-57. Hori, H., Nagaoka, Y., Murayama, M., Kutsuna, S., 2008. Efficient decomposition of perfluorocarboxylic acids and alternative fluorochemical surfactants in hot water. Environmental Science & Technology 42, 7438-7443. Houas, A., Lachheb, H., Ksibi, M., Elaloui, E., Guillard, C., Herrmann, J.-M., 2001. Photocatalytic degradation pathway of methylene blue in water. Applied Catalysis B: Environmental 31, 145-157. House, D.A., 1962. Kinetics and mechanism of oxidations by peroxydisulfate. Chemical Reviews 62, 185-203. Huang, K.-C., Couttenye, R.A., Hoag, G.E., 2002. Kinetics of heat-assisted persulfate oxidation of methyl tert-butyl ether (MTBE). Chemosphere 49, 413-420. Huang, K.-C., Zhao, Z., Hoag, G.E., Dahmani, A., Block, P.A., 2005. Degradation of volatile organic compounds with thermally activated persulfate oxidation. Chemosphere 61, 551-560. Huie, R.E., Clifton, C.L., Kafafi, S.A., 1991a. Rate constants for hydrogen abstraction reactions of the sulfate radical, SO4-‧: Experimental and theoretical results for cyclic ethers. Journal of Physical Chemistry 95, 9336-9340. Huie, R.E., Clifton, C.L., Neta, P., 1991b. Electron transfer reaction rates and equilibria of the carbonate and sulfate radical anions. International Journal of Radiation Applications and Instrumentation. Part C. Radiation Physics and Chemistry 38, 477-481. Huling, S.G., Jones, P.K., 2006. Research on chemical oxidation/in situ chemical oxidation. In: Groundwater and Ecosystem Restoration Research. USEPA http://www.epa.gov/ada/topics/oxidation.html. Huyer, E.S., 1970. Free-Radical Chain Reactions. John Wiley & Sons Inc, New York. Irmak, S., Kusvuran, E., Erbatur, O., 2004. Degradation of 4-chloro-2-methylphenol in aqueous solution by UV irradiation in the presence of titanium dioxide. Applied Catalysis B: Environmental 54, 85-91. ITRC, 2005. Technical and Regulatory Guidance for In Situ Chemical Oxidation of Contaminated Soil and Groundwater. Technical/Regulatory Guideline, 2nd ed., Washington, DC. Johnson, R.L., Tratnyek, P.G., Johnson, R.O., 2008. Persulfate persistence under thermal activation conditions. Environmental Science & Technology 42, 9350-9356. Kelner, M.J., Alexander, N.M., 1985. Methylene blue directly oxidizes glutathione without the intermediate formation of hydrogen peroxide. Journal of Biological Chemistry 260, 15168-15171. Kim, J., Edwards, J.O., 1995. A study of cobalt catalysis and copper modification in the coupled decompositions of hydrogen peroxide and peroxomonosulfate ion. Inorganica Chimica Acta 235, 9-13. Kishore, K., Guha, S.N., Mahadevan, J., Moorthy, P.N., Mittal, J.P., 1989. Redox reactions of methylene blue: A pulse radiolysis study. International Journal of Radiation Applications and Instrumentation. Part C. Radiation Physics and Chemistry 34, 721-727. Kislenko, V.N., Berlin, A.A., Litovchenko, N.V., 1995. Kinetics of glucose oxidation with persulfate ions, catalyzed by iron salts. Russian Journal of General Chemistry 65, 1092-1096 Kolthoff, I.M., Medalia, A.I., Raaen, H.P., 1951. The reaction between ferrous iron and peroxides. IV. Reaction with potassium persulfate. Journal of the American Chemical Society 73, 1733-1739. Kolthoff, I.M., Miller, I.K., 1951. The chemistry of persulfate. I. The kinetics and mechanism of the decomposition of the persulfate ion in aqueous medium. Journal of the American Chemical Society 73, 3055-3059. Kolthoff, I.M., Stenger, V.A., 1947. Volumetric analysis. In: Titration Methods: Acid-Base, Precipitation, and Complex Reactions. Interscience Publishers, New York, USA Konstantinou, I.K., Albanis, T.A., 2004. TiO2-assisted photocatalytic degradation of azo dyes in aqueous solution: kinetic and mechanistic investigations: A review. Applied Catalysis B: Environmental 49, 1-14. Kumar, K.V., Kumaran, A., 2005. Removal of methylene blue by mango seed kernel powder. Biochemical Engineering Journal 27, 83-93. Latimer, W.M., 1952. Oxidation Potentials. Prentice-Hall Englewood Cliffs lnc, New Jersey, USA. Lawrence, N.S., Davis, J., Jiang, L., Jones, T.G.J., Davies, S.N., Compton, R.G., 2000. The electrochemical analog of the methylene blue reaction: A novel amperometric approach to the detection of hydrogen sulfide. Electroanalysis 12, 1453-1460. Lawrence, N.S., Davis, J., Jiang, L., Jones, T.G.J., Davies, S.N., Compton, R.G., 2001. Electrochemically Initiated 1,4-nucleophilic substitutions: A general strategy for the analytical detection of hydrogen sulfide. Electroanalysis 13, 432-436. Lawrence, N.S., Jiang, L., Jones, T.G.J., Compton, R.G., 2003. Voltammetric characterization of a N,N''-diphenyl-p-phenylenediamine-loaded screen-printed electrode: A disposable sensor for hydrogen sulfide. Analytical Chemistry 75, 2054-2059. Lee, J.-W., Choi, S.-P., Thiruvenkatachari, R., Shim, W.-G., Moon, H., 2006. Evaluation of the performance of adsorption and coagulation processes for the maximum removal of reactive dyes. Dyes and Pigments 69, 196-203. Lee, Y.-C., Lo, S.-L., Chiueh, P.-T., Chang, D.-G., 2009. Efficient decomposition of perfluorocarboxylic acids in aqueous solution using microwave-induced persulfate. Water Research 43, 2811-2816. Lee, Y.-C., Lo, S.-L., Chiueh, P.-T., Liou, Y.-H., Chen, M.-L., 2010. Microwave-hydrothermal decomposition of perfluorooctanoic acid in water by iron-activated persulfate oxidation. Water Research 44, 886-892. Lenka, S., Dash, S.B., 1983. Polymerization of acrylonitrile initiated by K2S2O8-Co(II) and K2S2O8-Mn(II) redox systems. Journal of Macromolecular Science: Part A - Chemistry 20, 397-407. Li, J., Zhu, X., Zhu, J., Cheng, Z., 2007. Microwave-assisted nitroxide-mediated miniemulsion polymerization of styrene. Radiation Physics and Chemistry 76, 23-26. Li, S.-X., Wei, D., Mak, N.-K., Cai, Z., Xu, X.-R., Li, H.-B., Jiang, Y., 2009. Degradation of diphenylamine by persulfate: Performance optimization, kinetics and mechanism. Journal of Hazardous Materials 164, 26-31. Liang, C., Bruell, C.J., 2008. Thermally activated persulfate oxidation of trichloroethylene: Experimental investigation of reaction orders. Industrial & Engineering Chemistry Research 47, 2912-2918. Liang, C., Bruell, C.J., Marley, M.C., Sperry, K.L., 2003. Thermally activated persulfate oxidation of trichloroethylene (TCE) and 1,1,1-trichloroethane (TCA) in aqueous systems and soil slurries. Soil and Sediment Contamination: An International Journal 12, 207-228. Liang, C., Su, H.-W., 2009. Identification of sulfate and hydroxyl radicals in thermally activated persulfate. Industrial & Engineering Chemistry Research 48, 5558-5562. Liang, C., Wang, Z.-S., Bruell, C.J., 2007. Influence of pH on persulfate oxidation of TCE at ambient temperatures. Chemosphere 66, 106-113. Liang, C., Wang, Z.-S., Mohanty, N., 2006. Influences of carbonate and chloride ions on persulfate oxidation of trichloroethylene at 20 0C. Science of The Total Environment 370, 271-277. Maleki, A., Nematollahi, D., 2009. An efficient electrochemical method for the synthesis of methylene blue. Electrochemistry Communications 11, 2261-2264. Martínez-Huitle, C.A., Brillas, E., 2009. Decontamination of wastewaters containing synthetic organic dyes by electrochemical methods: A general review. Applied Catalysis B: Environmental 87, 105-145. Modarai, B., Kapadia, Y.K., Kerins, M., Terris, J., 2002. Methylene blue: A treatment for severe methaemoglobinaemia secondary to misuse of amyl nitrite. Emergency Medicine Journal 19, 270-270. Mora, V.C., Rosso, J.A., Carrillo Le Roux, G., Mártire, D.O., Gonzalez, M.C., 2009. Thermally activated peroxydisulfate in the presence of additives: A clean method for the degradation of pollutants. Chemosphere 75, 1405-1409. Muruganandham, M., Swaminathan, M., 2006. Photocatalytic decolourisation and degradation of reactive orange 4 by TiO2-UV process. Dyes and Pigments 68, 133-142. Muthuraman, G., Teng, T.T., Leh, C.P., Norli, I., 2009. Extraction and recovery of methylene blue from industrial wastewater using benzoic acid as an extractant. Journal of Hazardous Materials 163, 363-369. Nadim, F., Huang, K.-C., Dahmani, A., 2006. Remediation of soil and ground water contaminated with PAH using heat and Fe(II)-EDTA catalyzed persulfate oxidation. Water, Air, & Soil Pollution: Focus 6, 227-232. Neta, P., Madhavan, V., Zemel, H., Fessenden, R., 1977. Rate constants and mechanism of reaction of SO4-‧with aromatic compounds. Journal of the American Chemical Society 99, 163-164. Norman, R.O.C., Storey, P.M., West, P.R., 1970. Electron spin resonance studies. Part XXV. Reactions of sulphate radical anion with organic compounds. Journal of the Chemical Society B, 1087-1095. Oh, S.-Y., Kim, H.-W., Park, J.-M., Park, H.-S., Yoon, C., 2009. Oxidation of polyvinyl alcohol by persulfate activated with heat, Fe2+, and zero-valent iron. Journal of Hazardous Materials 168, 346-351. Pennington, D.E., Haim, A., 1968. Stoichiometry and mechanism of the chromium(II)-peroxydisulfate reaction. Journal of the American Chemical Society 90, 3700-3704. Peyton, G.R., 1993. The free-radical chemistry of persulfate-based total organic carbon analyzers. Marine Chemistry 41, 91-103. Satoh, A.Y., Trosko, J.E., Masten, S.J., 2007. Methylene blue dye test for rapid qualitative detection of hydroxyl radicals formed in a Fenton''s reaction aqueous solution. Environmental Science & Technology 41, 2881-2887. Schirmer, R.H., Coulibaly, B., Stich, A., Scheiwein, M., Merkle, H., Eubel, J., Becker, K., Becher, H., Müller, O., Zich, T., Schiek, W., Kouyaté, B., 2003. Methylene blue as an antimalarial agent. Redox Report 8, 272-275. Skarzewski, J., 1984. Cerium catalyzed persulfate oxidation of polycyclic aromatic hydrocarbons to quinones. Tetrahedron 40, 4997-5000. Steiner, N., Eul, W., 2006. Peroxides, inorganic. Kirk-Othmer Encyclopedia of Chemical Technology 5th ed., Vol.18. Wiley, New York, pp. 391-425. Syoufian, A., Nakashima, K., 2007. Degradation of methylene blue in aqueous dispersion of hollow titania photocatalyst: Optimization of reaction by peroxydisulfate electron scavenger. Journal of Colloid and Interface Science 313, 213-218. Syoufian, A., Nakashima, K., 2008. Degradation of methylene blue in aqueous dispersion of hollow titania photocatalyst: Study of reaction enhancement by various electron scavengers. Journal of Colloid and Interface Science 317, 507-512. Tsao, M.-S., Wilmarth, W.K., 1959. The aqueous chemistry of Inorganic free radicals. II. The mechanism of the photolytic decomposition of aqueous persulfate ion and evidence regarding the sulfate hydroxyl radical interconversion equilibrium. Journal of Physical Chemistry 63, 346-353. Umeda, N., Nibe, H., Hara, T., Hirazawa, N., 2006. Effects of various treatments on hatching of eggs and viability of oncomiracidia of the monogenean pseudodactylogyrus anguillae and pseudodactylogyrus bini. Aquaculture 253, 148-153. Van Eldik, R., Harris, G.M., 1980. Kinetics and mechanism of the formation, acid-catalyzed decomposition, and intramolecular redox reaction of oxygen-bonded (sulfito)pentaamminecobalt(III) ions in aqueous solution. Inorganic Chemistry 19, 880-886. Waldemer, R.H., Tratnyek, P.G., Johnson, R.L., Nurmi, J.T., 2007. Oxidation of chlorinated ethenes by heat-activated persulfate: Kinetics and products. Environmental Science & Technology 41, 1010-1015. Walling, C., Camaioni, D.M., Kim, S.S., 1978. Aromatic hydroxylation by peroxydisulfate. Journal of the American Chemical Society 100, 4814-4818. Wang, Y., Hong, C.-s., 1999. Effect of hydrogen peroxide, periodate and persulfate on photocatalysis of 2-chlorobiphenyl in aqueous TiO2 suspensions. Water Research 33, 2031-2036. Xu, X.-R., Li, X.-Z., 2010. Degradation of azo dye Orange G in aqueous solutions by persulfate with ferrous ion. Separation and Purification Technology 72, 105-111. Xu, X.-R., Zhao, Z.-Y., Li, X.-Y., Gu, J.-D., 2004. Chemical oxidative degradation of methyl tert-butyl ether in aqueous solution by Fenton''s reagent. Chemosphere 55, 73-79. Yang, S., Wang, P., Yang, X., Wei, G., Zhang, W., Shan, L., 2009. A novel advanced oxidation process to degrade organic pollutants in wastewater: Microwave-activated persulfate oxidation. Journal of Environmental Sciences 21, 1175-1180. Zhu, X., Chen, J., Cheng, Z., Lu, J., Zhu, J., 2003a. Emulsion polymerization of styrene under pulsed microwave irradiation. Journal of Applied Polymer Science 89, 28-35. Zhu, X., Chen, J., Zhou, N., Cheng, Z., Lu, J., 2003b. Emulsion polymerization of methyl methacrylate under pulsed microwave irradiation. European Polymer Journal 39, 1187-1193. Zollinger, H., 1991. Color Chemistry: Synthesis, Properties and Applications of Organic Dyes and Pigments, second revised ed. VCH, Weinheim. 石濤, 2001. 環境化學. 鼎茂圖書出版有限公司, 台北市, 台灣. 李尚凡, 林振隆, 陳寶祺, 張漢昌, 蔡明瞭, 1995. 化學反應工程. 高立圖書有限公司, 台北市, 台灣. 鄧禮堂, 1989. 反應工程. 高立圖書有限公司, 台北市, 台灣.
摘要: 過硫酸鈉(sodium persulfate, SPS)可經由熱活化產生硫酸根自由基(SO4-‧)強氧化劑(E0 = 2.6 V),於酸性pH環境下,SO4-‧為優勢之氧化劑自由基物種;於中性pH環境下,SO4-‧可與氫氧根離子(OH-)進行自由基轉換反應,生成氫氧根自由基(OH‧);於鹼性pH環境下,OH‧為主要之氧化劑自由基物種。由於污染物對自由基之反應速率不盡相同,造成各污染物於不同pH條件下反應速率及去除效率亦不相同。因此本研究推導於酸性(pH = 3)、中性(pH = 7)及鹼性(pH = 11)環境下,70℃熱活化過硫酸鹽降解甲基藍之反應動力式,並求得甲基藍與硫酸根自由基間之反應速率常數及SO4-‧/OH‧之濃度。 過硫酸鹽與甲基藍反應動力實驗結果顯示,當溫度為60、70及80℃,所有pH環境下,反應一小時後,甲基藍之脫色率皆 > 95 %,且皆符合假一階反應動力。過硫酸鹽降解甲基藍之脫色速率於不同pH條件下之影響為:pH 11 > pH 3 > pH 7;於不同溫度下之影響則為:80℃ > 70℃ > 60℃。當溫度為70及80℃時,所有pH條件下,甲基藍與過硫酸鹽反應一小時後,TOC之去除率皆 > 90 %;當溫度為60℃時,pH 分別為 3、7及11條件下,TOC之去除率僅為37、30及57 %。由動力分析實驗結果求得SO4-‧與甲基藍之反應速率常數 ~ 108 M-1s-1,並證實於酸性(pH 3)環境下,SO4-‧(~ 10-6 M)為優勢自由基,活化能(Ea) = 87.17±2.09 kJ/mole;中性(pH 7)環境下,SO4-‧(~ 10-11 M)與OH‧(~ 10-10 M)同時存在,Ea = 109.06±2.70 kJ/mole;鹼性(pH 11)環境下,OH‧(~ 10-6 M)為主要自由基,Ea = 89.68±2.21 kJ/mole。
Sodium persulfate can be thermally activated to produce sulfate radicals (SO4-‧) (E0 = 2.6 V). It has been demonstrated that under acidic condition, SO4-‧ is the dominant oxidant radical species; in neutral condition, the SO4-‧ can proceed radical interconversion reaction with hydroxyl ions to generate the hydroxyl radical (OH‧); at alkaline condition, OH‧is the major oxidant radical species. Due to that the interaction between different radicals and specific pollutants is dependent of pH and hence the destruction of various pollutants varies at various pHs, this study focused on the deduction of the kinetics of thermally activated persulfate oxidation of methylene blue (MB) at acidic (pH = 3), neutral (pH = 7) and alkaline (pH = 11) conditions. Moreover, the reaction rate constant between MB and SO4-‧and the concentrations of both SO4-‧and OH‧were determined. The kinetic results of persulfate oxidation of MB revealed that at 60, 70 and 80°C under pH = 3, 7 and 11, the decolorization of MB achieved > 95 % at around 1 hour. The degradation of MB was found to follow pseudo-first-order kinetics model. The effect of pH on MB decolorization rate was pH 11 > pH 3 > pH 7; the effect of temperature was 80°C > 70°C > 60°C. At 70 and 80°C under pH = 3, 7 and 11, the removal of total organic carbons (TOC) reached > 90 % after around 1 hour while at 60°C under pH 3, 7 and 11 TOC removals were 37, 30, and 57 %, respectively. It was also demonstrated that the reaction rate constant between SO4-‧ and MB is around 108 M-1s-1, and confirmed that at acidic (pH 3) condition, SO4-‧, with concentration of ~ 10-6 M and reaction activation energy (Ea) = 87.17±2.09 kJ/mole, is the dominant radical; at neutral (pH 7) condition, SO4-‧, with concentration of ~ 10-11 M, and OH‧ , with concentration of ~ 10-10 M, are simultaneously present, Ea = 109.06±2.70 kJ/mole; at alkaline (pH 11) condition, OH‧, with concentration of ~ 10-6 M, is the major radical, Ea = 89.68±2.21 kJ/mole.
URI: http://hdl.handle.net/11455/5733
其他識別: U0005-0807201011590600
文章連結: http://www.airitilibrary.com/Publication/alDetailedMesh1?DocID=U0005-0807201011590600
Appears in Collections:環境工程學系所

文件中的檔案:

取得全文請前往華藝線上圖書館



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.