Carbon nanotube (CNT) was used as an activator to activate persulfate (PS) to decolorize the azo dye, acid orange 7 (AO7). Effect of PS dosage, CNT loading, initial pH and reaction temperature on decolorization of AO7 was investigated. The results indicated that completely decolorization of AO7 was achieved within 480min when 0.2g/L of CNT and 20 of n(PS)/n(AO7) were present in the system. AO7 decolorization was increased with increasing PS dosage, raising CNT loading and elevating temperature, and neutral pH was most favorable for AO7 decolorization. The oxidative degradation of AO7 mainly took place on the surface of CNT and the activation energy (Ea) was determined to be 46.76kJ/mol. From the analysis of UV-Vis spectra, GC-MS and TOC during the reaction, the azo band and naphthalene ring of AO7 were proposed to be destroyed to generate other small intermediate containing benzene, and finally mineralized to CO2 and H2O.
Han D,Wan J,Ma Y,et al.Enhanced decolorization of Orange G in a Fe (Ⅱ)-EDDS activated persulfate process by accelerating the regeneration of ferrous iron with hydroxylamine[J].Chemical Engineering Journal,2014,256:316-323.
[2]
Lin H,Zhang H,Hou L.Degradation of C.I.Acid Orange 7in aqueous solution by a novel electro/Fe3O4/PDS process[J].Journal of Hazardous Materials,2014,276:182-191.
[3]
Møller P,Wallin H.Genotoxic hazards of azo pigments and other colorants related to 1-phenylazo-2-hydroxynaphthalene[J].Mutation Research/Reviews in Mutation Research,2000,462(1):13-30.
[4]
Wang M,Liu X,Pan B,et al.Photodegradation of Acid Orange 7 in a UV/acetylacetone process[J].Chemosphere,2013,93(11):2877-2882.
[5]
Mezohegyi G,Kolodkin A,Castro U I,et al.Effective anaerobic decolorization of azo dye Acid Orange 7in continuous upflow packed-bed reactor using biological activated carbon system[J].Industrial&Engineering Chemistry Research,2007,46(21):6788-6792.
[6]
Van der Zee F P,Villaverde S.Combined anaerobic-aerobic treatment of azo dyes-a short review of bioreactor studies[J].Water Research,2005,39(8):1425-1440.
[7]
Martínez-Huitle C A,Brillas E.Decontamination of wastewaters containing synthetic organic dyes by electrochemical methods:a general review[J].Applied Catalysis B:Environmental,2009,87(3/4):105-145.
[8]
Forgacs E,Cserhati T,Oros G.Removal of synthetic dyes from wastewaters:A review[J].Environ.Internat.,2004,30(7):953-971.
[9]
Daneshvar N,Salari D,Khataee A.Photocatalytic degradation of azo dye acid red 14in water on ZnO as an alternative catalyst to TiO2[J].Journal of Photochemistry and Photobiology A:Chemistry,2004,162(2/3):317-322.
[10]
Kusvuran E,Gulnaz O,Irmak S,et al.Comparison of several advanced oxidation processes for the decolorization of Reactive Red 120azo dye in aqueous solution[J].Journal of Hazardous Materials,2004,109(1-3):85-93.
[11]
Zhang B T,Zhang Y,Teng Y H,et al.Sulfate Radical and Its Application in Decontamination Technologies[J].Critical Reviews in Environmental Science and Technology,2015,45(16):1756-1800.
[12]
Tsitonaki A,Petri B,Crimi M,et al.In Situ Chemical Oxidation of Contaminated Soil and Groundwater Using Persulfate:A Review[J].Critical Reviews in Environmental Science and Technology,2010,40(1):55-91.
[13]
Anipsitakis G P,Dionysiou D D.Radical Generation by the Interaction of Transition Metals with Common Oxidants[J].Environ.Sci.Technol.,2004,38(13):3705-3712.
[14]
Guan Y H,Ma J,Li X C,et al.Influence of pH on the Formation of Sulfate and Hydroxyl Radicals in the UV/Peroxymonosulfate System[J].Environ.Sci.Technol.,2011,45(21):9308-9314.
[15]
Furman O S,Teel A L,Watts R J.Mechanism of Base Activation of Persulfate[J].Environ.Sci.Technol.,2010,44(16):6423-6428.
[16]
Johnson R L,Tratnyek P G,Johnson R O B.Persulfate Persistence under Thermal Activation Conditions[J].Environ.Sci.Technol.,2008,42(24):9350-9356.
[17]
Shukla P R,Wang S B,Sun H Q,et al.Activated carbon supported cobalt catalysts for advanced oxidation of organic contaminants in aqueous solution[J].Applied Catalysis B:Environmental,2010,100(3/4):529-534.
[18]
Faria P C C,Orfao J J M,Pereira M F R.Activated carbon and ceria catalysts applied to the catalytic ozonation of dyes and textile effluents[J].Applied Catalysis B:Environmental,2009,88(3/4):341-350.
[19]
Huling S G,Jones P K,Lee T R.Iron optimization for fenton-driven oxidation of MTBE-spent granular activated carbon[J].Environ.Sci.Technol.,2007,41(11):4090-4096.
[20]
Zhang J,Shao X T,Shi C,et al.Decolorization of Acid Orange 7with peroxymonosulfate oxidation catalyzed by granular activated carbon[J].Chem.Engineering J.,2013,232:259-265.
[21]
Yang S Y,Xiao T,Zhang J,et al.Activated carbon fiber as heterogeneous catalyst of peroxymonosulfate activation for efficient degradation of Acid Orange 7in aqueous solution[J].Separation and Purification Technology,2015,143:19-26.
[22]
Yang S Y,Yang X,Shao X T,et al.Activated carbon catalyzed persulfate oxidation of Azo dye acid orange 7at ambient temperature[J].J.of Hazardous Materials,2011,186(1):659-666.
[23]
Sun H,Kwan C,Suvorova A,et al.Catalytic oxidation of organic pollutants on pristine and surface nitrogen-modified carbon nanotubes with sulfate radicals[J].Applied Catalysis B:Environmental,2014,154-155,134-141.
[24]
Zhang J,Su D,Zhang A,et al.Nanocarbon as Robust Catalyst:Mechanistic Insight into Carbon-Mediated Catalysis[J].Angewandte Chemie,2007,119(38):7460-7464.
Chen J,Qian Y,Liu H,et al.Oxidative degradation of diclofenac by thermally activated persulfate:implication for ISCO[J].Environ.Sci.Poll.Res.,2016,23(4):3824-3833.
[27]
Luo J,Peng F,Yu H,et al.Aerobic Liquid-Phase Oxidation of Ethylbenzene to Acetophenone Catalyzed by Carbon Nanotubes[J].Chem.Cat.Chem.,2013,5(6):1578-1586.
[28]
Lee H,Lee H J,Jeong J,et al.Activation of persulfates by carbon nanotubes:Oxidation of organic compounds by nonradical mechanism[J].Chemical Engineering Journal,2015,266:28-33.
[29]
Huang K C,Couttenye R A,Hoag G E.Kinetics of heat-assisted persulfate oxidation of methyl tert-butyl ether (MTBE)[J].Chemosphere,2002,49(4):413-420.
[30]
Cai C,Zhang H,Zhong X,et al.Ultrasound enhanced heterogeneous activation of peroxymonosulfate by a bimetallic Fe-Co/SBA-15 catalyst for the degradation of Orange Ⅱ in water[J].Journal of Hazardous Materials,2015,283:70-79.
[31]
Nie M,Yang Y,Zhang Z,et al.Degradation of chloramphenicol by thermally activated persulfate in aqueous solution[J].Chemical Engineering Journal,2014,246:373-382.
[32]
Yan J C,Lei M,Zhu L H,et al.Degradation of sulfamonomethoxine with Fe3O4magnetic nanoparticles as heterogeneous activator of persulfate[J].Journal of Hazardous Materials,2011,186(2/3):1398-1404.
[33]
Furman O,Teel A,Ahmad M,et al.Effect of Basicity on Persulfate Reactivity[J].J.Environmental Engineering,2011,137(4):241-247.
[34]
Liang H Y,Zhang Y Q,Huang S B,et al.Oxidative degradation of p-chloroaniline by copper oxidate activated persulfate[J].Chemical Engineering Journal,2013,218:384-391.
[35]
Bauer C,Jacques P,Kalt A.Photooxidation of an azo dye induced by visible light incident on the surface of TiO2[J].Journal of Photochemistry and Photobiology A:Chemistry,2001,140(1):87-92.
[36]
Wu F,Deng N S,Hua H L.Degradation mechanism of azo dye CI reactive red 2by iron powder reduction and photooxidation in aqueous solutions[J].Chemosphere,2000,41(8):1233-1238.
[1]
Han D,Wan J,Ma Y,et al.Enhanced decolorization of Orange G in a Fe (Ⅱ)-EDDS activated persulfate process by accelerating the regeneration of ferrous iron with hydroxylamine[J].Chemical Engineering Journal,2014,256:316-323.
[2]
Lin H,Zhang H,Hou L.Degradation of C.I.Acid Orange 7in aqueous solution by a novel electro/Fe3O4/PDS process[J].Journal of Hazardous Materials,2014,276:182-191.
[3]
Møller P,Wallin H.Genotoxic hazards of azo pigments and other colorants related to 1-phenylazo-2-hydroxynaphthalene[J].Mutation Research/Reviews in Mutation Research,2000,462(1):13-30.
[4]
Wang M,Liu X,Pan B,et al.Photodegradation of Acid Orange 7 in a UV/acetylacetone process[J].Chemosphere,2013,93(11):2877-2882.
[5]
Mezohegyi G,Kolodkin A,Castro U I,et al.Effective anaerobic decolorization of azo dye Acid Orange 7in continuous upflow packed-bed reactor using biological activated carbon system[J].Industrial&Engineering Chemistry Research,2007,46(21):6788-6792.
[6]
Van der Zee F P,Villaverde S.Combined anaerobic-aerobic treatment of azo dyes-a short review of bioreactor studies[J].Water Research,2005,39(8):1425-1440.
[7]
Martínez-Huitle C A,Brillas E.Decontamination of wastewaters containing synthetic organic dyes by electrochemical methods:a general review[J].Applied Catalysis B:Environmental,2009,87(3/4):105-145.
[8]
Forgacs E,Cserhati T,Oros G.Removal of synthetic dyes from wastewaters:A review[J].Environ.Internat.,2004,30(7):953-971.
[9]
Daneshvar N,Salari D,Khataee A.Photocatalytic degradation of azo dye acid red 14in water on ZnO as an alternative catalyst to TiO2[J].Journal of Photochemistry and Photobiology A:Chemistry,2004,162(2/3):317-322.
[10]
Kusvuran E,Gulnaz O,Irmak S,et al.Comparison of several advanced oxidation processes for the decolorization of Reactive Red 120azo dye in aqueous solution[J].Journal of Hazardous Materials,2004,109(1-3):85-93.
[11]
Zhang B T,Zhang Y,Teng Y H,et al.Sulfate Radical and Its Application in Decontamination Technologies[J].Critical Reviews in Environmental Science and Technology,2015,45(16):1756-1800.
[12]
Tsitonaki A,Petri B,Crimi M,et al.In Situ Chemical Oxidation of Contaminated Soil and Groundwater Using Persulfate:A Review[J].Critical Reviews in Environmental Science and Technology,2010,40(1):55-91.
[13]
Anipsitakis G P,Dionysiou D D.Radical Generation by the Interaction of Transition Metals with Common Oxidants[J].Environ.Sci.Technol.,2004,38(13):3705-3712.
[14]
Guan Y H,Ma J,Li X C,et al.Influence of pH on the Formation of Sulfate and Hydroxyl Radicals in the UV/Peroxymonosulfate System[J].Environ.Sci.Technol.,2011,45(21):9308-9314.
[15]
Furman O S,Teel A L,Watts R J.Mechanism of Base Activation of Persulfate[J].Environ.Sci.Technol.,2010,44(16):6423-6428.
[16]
Johnson R L,Tratnyek P G,Johnson R O B.Persulfate Persistence under Thermal Activation Conditions[J].Environ.Sci.Technol.,2008,42(24):9350-9356.
[17]
Shukla P R,Wang S B,Sun H Q,et al.Activated carbon supported cobalt catalysts for advanced oxidation of organic contaminants in aqueous solution[J].Applied Catalysis B:Environmental,2010,100(3/4):529-534.
[18]
Faria P C C,Orfao J J M,Pereira M F R.Activated carbon and ceria catalysts applied to the catalytic ozonation of dyes and textile effluents[J].Applied Catalysis B:Environmental,2009,88(3/4):341-350.
[19]
Huling S G,Jones P K,Lee T R.Iron optimization for fenton-driven oxidation of MTBE-spent granular activated carbon[J].Environ.Sci.Technol.,2007,41(11):4090-4096.
[20]
Zhang J,Shao X T,Shi C,et al.Decolorization of Acid Orange 7with peroxymonosulfate oxidation catalyzed by granular activated carbon[J].Chem.Engineering J.,2013,232:259-265.
[21]
Yang S Y,Xiao T,Zhang J,et al.Activated carbon fiber as heterogeneous catalyst of peroxymonosulfate activation for efficient degradation of Acid Orange 7in aqueous solution[J].Separation and Purification Technology,2015,143:19-26.
[22]
Yang S Y,Yang X,Shao X T,et al.Activated carbon catalyzed persulfate oxidation of Azo dye acid orange 7at ambient temperature[J].J.of Hazardous Materials,2011,186(1):659-666.
[23]
Sun H,Kwan C,Suvorova A,et al.Catalytic oxidation of organic pollutants on pristine and surface nitrogen-modified carbon nanotubes with sulfate radicals[J].Applied Catalysis B:Environmental,2014,154-155,134-141.
[24]
Zhang J,Su D,Zhang A,et al.Nanocarbon as Robust Catalyst:Mechanistic Insight into Carbon-Mediated Catalysis[J].Angewandte Chemie,2007,119(38):7460-7464.
Chen J,Qian Y,Liu H,et al.Oxidative degradation of diclofenac by thermally activated persulfate:implication for ISCO[J].Environ.Sci.Poll.Res.,2016,23(4):3824-3833.
[27]
Luo J,Peng F,Yu H,et al.Aerobic Liquid-Phase Oxidation of Ethylbenzene to Acetophenone Catalyzed by Carbon Nanotubes[J].Chem.Cat.Chem.,2013,5(6):1578-1586.
[28]
Lee H,Lee H J,Jeong J,et al.Activation of persulfates by carbon nanotubes:Oxidation of organic compounds by nonradical mechanism[J].Chemical Engineering Journal,2015,266:28-33.
[29]
Huang K C,Couttenye R A,Hoag G E.Kinetics of heat-assisted persulfate oxidation of methyl tert-butyl ether (MTBE)[J].Chemosphere,2002,49(4):413-420.
[30]
Cai C,Zhang H,Zhong X,et al.Ultrasound enhanced heterogeneous activation of peroxymonosulfate by a bimetallic Fe-Co/SBA-15 catalyst for the degradation of Orange Ⅱ in water[J].Journal of Hazardous Materials,2015,283:70-79.
[31]
Nie M,Yang Y,Zhang Z,et al.Degradation of chloramphenicol by thermally activated persulfate in aqueous solution[J].Chemical Engineering Journal,2014,246:373-382.
[32]
Yan J C,Lei M,Zhu L H,et al.Degradation of sulfamonomethoxine with Fe3O4magnetic nanoparticles as heterogeneous activator of persulfate[J].Journal of Hazardous Materials,2011,186(2/3):1398-1404.
[33]
Furman O,Teel A,Ahmad M,et al.Effect of Basicity on Persulfate Reactivity[J].J.Environmental Engineering,2011,137(4):241-247.
[34]
Liang H Y,Zhang Y Q,Huang S B,et al.Oxidative degradation of p-chloroaniline by copper oxidate activated persulfate[J].Chemical Engineering Journal,2013,218:384-391.
[35]
Bauer C,Jacques P,Kalt A.Photooxidation of an azo dye induced by visible light incident on the surface of TiO2[J].Journal of Photochemistry and Photobiology A:Chemistry,2001,140(1):87-92.
[36]
Wu F,Deng N S,Hua H L.Degradation mechanism of azo dye CI reactive red 2by iron powder reduction and photooxidation in aqueous solutions[J].Chemosphere,2000,41(8):1233-1238.
