Effect of alcohols on scavenging efficiencies to hydroxyl radical in UV-Fenton system
DAI Hui-wang1,2, CHEN Jian-xin1,2, MIAO Xiao-zeng1,2, JIANG Bo-quan1, GONG Xian3
1. School of Resources, Environmental and Chemical Engineering, Nanchang University, Nanchang 330031, China; 2. The Key Laboratory of Poyang Lake Environment and Resource Utilization of Ministry of Education, Nanchang University, Nanchang 330031, China; 3. Nanchang Environmental Monitoring Station, Nanchang 330038, China
Abstract：The comparative experiment of scavenging efficiencies of alcohols to hydroxyl radical (·OH) in UV-Fenton system was designed. In homogeneous and heterogeneous UV-Fenton systems, the effects of alcohol species and initial concentration on scavenging rate to ·OH was studied. And the concentration of ·OH was quantified by fluorescence spectra measurement in heterogeneous UV-Fenton system with alcohols as scavenging reagents. The results showed that the scavenging ability of alkanols to ·OH was in the order tert-butanol > isopropanol > ethanol > n-propanol > n-butanol > methanol, and as for polybasic alcohols, its scavenging ability to ·OH enhanced with increasing chain length and hydroxyl number. Among those alcohols, the two stage scavenging rates of glycerol to ·OH in heterogeneous UV-Fenton system were 86.7% and 61.7%, respectively; which were 79.6% and 65.6% in homogeneous UV-Fenton system. The results indicated that glycerol could scavenge ·OH high efficiently and stably in both homogeneous and heterogeneous UV-Fenton systems and can be used as a new efficient scavenger to hydroxyl radical.
Feng J Y, Hu X J, Yue P L, et al. Discoloration and mineralization of Reactive Red HE-3B by heterogeneous photo-Fenton reaction[J]. Water Research, 2003,37:3776-3784.
[2]
He J, Ma W H, He J J, et al. Photooxidation of azo dye in aqueous dispersions of H2O2/α-FeOOH[J]. Applied Catalyst B:Environmental, 2002,39:211-220.
Li M K, Qiang Z M, Pulgarin C, et al. Accelerated methylene blue(MB) degradation by Fenton reagent exposed to UV or VUV/UV light in an innovative micro photo-reactor[J]. Applied Catalyst B:Environmental, 2016,187:83-89.
[5]
Elmolla E S, Chaudhuri M, Degradation of the antibiotics amoxicillin, ampicillin and cloxacillin in aqueous solution by the photo-Fenton process[J]. Journal of Hazardous Materials, 2009,172:1476-1481.
[6]
Lin Z R, Zhao L, Dong Y H. Quantitative characterization of hydroxyl radical generation in a goethite-catalyzed Fenton-like reaction[J]. Chemosphere, 2015,141:7-12.
[7]
Louit G, Foley S, Cabillac J, et al. The reaction of coumarin with the OH radical revisited:hydroxylation product analysis determined by fluorescence and chromatography[J]. Radiation Physics and Chemistry, 2005,72:119-124.
[8]
Zhang J, Nosaka Y. Quantitative detection of OH radicals for investigating the reaction mechanism of various Visible-Light TiO2 photocatalysts in aqueous suspension[J]. The Journal of Physical and Chemistry C, 2013,117:1383-1391.
Wang Y, Lin X H, Shao Z Z, et al. Comparison of Fenton, UV-Fenton and nano-Fe3O4 catalyzed UV-Fenton in degradation of phloroglucinol under neutral and alkaline conditions:Role of complexation of Fe3+ with hydroxyl group in phloroglucinol[J]. Chemical Engineering Journal, 2017,313:938-945.
[11]
Zhang J, Shao X T, Shi C, et al. Decolorization of Acid Orange 7with peroxymonosulfate oxidation catalyzed by granular activated carbon[J]. Chemical Engineering Journal, 2013,232:259-265.
[12]
Song S, Xu L J, He Z Q, et al. Mechanism of the photocatalytic degradation of C.I. reactive black 5 at pH 12.0using SrTiO3/CeO2 as the catalyst[J]. Environmental Science &Technology, 2007,41:5846-5853.
Monteagudo J M, Duran A, San Martin I, et al. Roles of different intermediate active species in the mineralization reactions of phenolic pollutants under a UV-A/C photo-Fenton process[J]. Applied Catal B:Environmental, 2011,106:242-249.
[15]
Hwang S C, Huling S G, Ko S, Fenton-like degradation of MTBE:Effect if iron counter anion and radical scavenger[J]. Chemosphere, 2010,78:563-568.
[16]
Xu L J, Wang J L, Magnetic nanoscaled Fe3O4/CeO2 composite as an efficient Fenton-Like heterogeneous catalyst for degradation of 4-Chlorphenol[J]. Environmental Science & Technology, 2012,46:10145-10153.
Tokumura M, Morito R, Hatayama R, et al. Iron redox cycling in hydroxyl radical generation during the photo-Fenton oxidative degradation:Dynamic change of hydroxyl radical concentration[J]. Applied Catal B:Environmental, 2011,106:565-576.
[19]
Maezono T, Tokumura M, Sekine M, et al. Hydroxyl radical concentration profile in photo-Fenton oxidation process:Generation and consumption of hydroxyl radicals during the discoloration of azo-dye Orange[J]. Chemosphere, 2011,82:Ⅱ 1422-1430.
[20]
Baba Y, Yatagai T, Harada T, et al. Hydroxyl radical generation in the photo-Fenton process:Effects of carboxylic acids on iron redox cycling[J]. Chemical Engineering Journal, 2015,277:229-241.
[21]
Chen J X, Zhu L Z. Catalytic degradation of Orange by Ⅱ UV-Fenton with hydroxyl-Fe-pillared bentonite in water[J]. Chemosphere, 2006,65:1249-1255.
[22]
Chen J X, Zhu L Z, UV-fenton discolouration and mineralization of Orange Over hydroxyl Ⅱ -Fe-pillared bentonite[J]. Journal of Photochemistry and Photobiology:A:Chemistry, 2007,188:56-64.
[23]
Li G T, Wong K H, Zhang X W, et al. Degradation of Acid Orange 7using magnetic AgBr under visible light:The roles of oxidizing species[J]. Chemosphere, 2009,76:1185-1191.
Wang M L, Fang G D, Liu P, et al. Fe3O4@β-CD nanocomposite as heterogeneous Fenton-like catalyst for enhanced degradation of 4-chlorophenol (4-CP)[J]. Applied Catal B:Environmental, 2016,188:113-122.
[28]
Buxton G V, Greenstock C L, Helman W P, et al. Critical review of rate constants for reactions of hydrated electrons, hydrogen atoms and hydroxyl radicals (·OH/·O-) in aqueous solution[J]. Journal of Physical and Chemical Reference Data, 1988,17:513-886.
[29]
Xue X F, Hanna K, Despas C, et al. Effect of chelating agent on the oxidation rate of PCP in the magnetite/H2O2 system at neutral pH[J]. Journal of Molecular Catalyst A:Chemical, 2009,311:29-35.
Chen F X, Xie S L, Huang X L et al. Ionothermal synthesis of Fe3O4 magnetic nanoparticles as efficient heterogeneous Fentonlike catalysts for degradation of organic pollutants with H2O2[J]. Journal of Hazardous Materials, 2017,322:152-162.
[32]
Romão J, Salata R, Park S Y, et al. Photocatalytic methanol assisted production of hydrogen with simultaneous degradation of methyl orange[J]. Applied Catalyst A:General, 2016,518:206-212.
