紫外光照条件下固体颗粒表面氧化铁对苯酚降解的抑制
Decreased phenol degradation by hematite under UV irradiation on HMT-silica surface
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摘要: 在负载氧化铁的硅胶颗粒(HMT-silica)表面探讨紫外光照下氧化铁对苯酚降解的影响机理.结果表明,硅胶表面负载的氧化铁可以降低苯酚的降解.光照50 h,吸附在硅胶上的苯酚(固相浓度0.75±0.17μg·mg-1)降解率为69.3%,而吸附在负载氧化铁硅胶颗粒上的苯酚降解率仅为17.7%.改变苯酚的固相浓度或者硅胶表面氧化铁的负载比例也出现同样的现象,排除了苯酚挥发和不同固体颗粒吸光度差别造成的影响.由自由基信号检测结果表明,产生这种影响的原因主要是在含氧化铁系统中生成的环境持久性自由基阻碍了苯酚的进一步降解.Abstract: In this study, the effects of hematite on phenol degradation on HMT-silica surface were investigated under UV irradiation. The results showed that, under UV irradiation, phenol degradation was reduced because of the coating of hematite on silica surface. After UV irradiation for 50 h, the degradation rate of phenol adsorbed on silica particles(particle concentration 0.75±0.17μg·mg-1) was 69.3%, while phenol degradation on HMT-silica was 17.7%. In addition, similar phenomena were observed when the phenol concentration or the ratio of hematite on the silica surface was changed. The impact of phenol evaporation and the light absorbance of solid particle were thus excluded. Environmentally persistent free radicals were observed on HMT-silica, which may hinder phenol degradation.
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Key words:
- phenol /
- hematite /
- UV irradiation /
- degradation rate /
- environmentally persistent free radicals.
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[1] CALACE N, NARDI E, PETRONIO B, et al. Adsorption of phenols by papermill sludges[J]. Environmental Pollution, 2002, 118(3):315-319. [2] MICHAŁOWICZ J, DUDA W. Phenols-sources and toxicity[J]. Polish Journal of Environmental Studies, 2007, 16(3):347-362. [3] 张建英, 丁腾达, 梁璐怡, 等. 水体生态系统对不同浓度水平苯酚污染的急性毒性响应[J]. 环境化学, 2012, 31(5):714-719. ZHANG J Y, DING T D, LIANG L Y, et al. Response of aquatic ecosystem to phenol pollution at different concentration levels[J]. Environmental Chemistry, 2012, 31(5):714-719(in Chinese)
[4] BOTAS J A, MELERO J A, MARTÍNEZ F, et al. Assessment of Fe2O3/SiO2 catalysts for the continuous treatment of phenol aqueous solutions in a fixed bed reactor[J]. Catalysis Today, 2010, 149(3-4):334-340. [5] GONDAL M, SAYEED M, ALARFAJ A. Activity comparison of Fe2O3, NiO, WO3, TiO2 semiconductor catalysts in phenol degradation by laser enhanced photo-catalytic process[J]. Chemical physics letters, 2007, 445(4-6):325-330. [6] GUO L, CHEN F, FAN X, et al. S-doped α-Fe2O3 as a highly active heterogeneous Fenton-like catalyst towards the degradation of acid orange 7 and phenol[J]. Applied Catalysis B:Environmental, 2010, 96(1-2):162-168. [7] KAVITHA V, PALANIVELU K. The role of ferrous ion in Fenton and photo-Fenton processes for the degradation of phenol[J]. Chemosphere, 2004, 55(9):1235-1243. [8] NEYENS E, BAEYENS J. A review of classic Fenton's peroxidation as an advanced oxidation technique[J]. Journal of Hazardous materials, 2003, 98(1-3):33-50. [9] 张德莉, 黄应平, 罗光富, 等. Fenton及Photo-Fenton反应研究进展[J]. 环境化学, 2006, 25(2):121-127. ZHANG D L, HUANG Y P, LUO F G, et al. Research progress of Fenton and Photo-Fenton reaction[J]. Environmental Chemistry, 2006, 25(2):121-127(in Chinese).
[10] DELLINGER B, LOMNICKI S, KHACHATRYAN L, et al. Formation and stabilization of persistent free radicals[J]. Proceedings of the Combustion Institute, 2007, 31(1):521-528. [11] LOMNICKI S, TRUONG H, VEJERANO E, et al. Copper oxide-based model of persistent free radical formation on combustion-derived particulate matter[J]. Environmental Science & Technology, 2008, 42(13):4982-4988. [12] VEJERANO E, LOMNICKI S, DELLINGER B. Formation and stabilization of combustion-generated environmentally persistent free radicals on an Fe(Ⅲ)2O3/silica surface[J]. Environmental Science & Technology, 2010, 45(2):589-594. [13] LI H, PAN B, LIAO S, et al. Formation of environmentally persistent free radicals as the mechanism for reduced catechol degradation on hematite-silica surface under UV irradiation[J]. Environmental Pollution, 2014, 188:153-158. [14] BATTISHA I, AFIFY H, HAMADA I. Structural and magnetic susceptibility studies of SiO2:Fe2O3 nano-composites prepared by sol-gel technique[J]. Journal of magnetism and magnetic materials, 2005, 292:440-446. [15] LI J J, MU Z, XU X Y, et al. A new and generic preparation method of mesoporous clay composites containing dispersed metal oxide nanoparticles[J]. Microporous and Mesoporous Materials, 2008, 114(1):214-221. [16] Hu C,Tang H X,Wang Y Z. Destruction of phenol aqueous solution by photocatalysis or direct photolysis[J]. Chemosphere, 2000, 41(8):1205-1209. [17] 李强, 霍丽华, 高山, 等. 准立方体α-Fe2O3 纳米薄膜的紫外和红外光谱研究[J]. 光散射学报, 2004, 15(4):297-299. LI Q, HUO L H, GAO S, et al. Study on UV and IR spectra of pseudocubic shaped α-Fe2O3 nano-films[J]. Environmental Chemistry, 2004, 15(4):297-299(in Chinese).
[18] NOVOTNY E H, MARTIN-NETO L. Effects of humidity and metal ions on the free radicals analysis of peat humus[J]. Geoderma, 2002, 106(3-4):305-317. [19] JEZIERSKI A, CZECHOWSKI F, JERZYKIEWICZ M, et al. EPR investigations of structure of humic acids from compost, soil, peat and soft brown coal upon oxidation and metal uptake[J]. Applied Magnetic Resonance, 2000, 18(1):127-136. [20] TRUONG H, LOMNICKI S, DELLINGER B. Potential for misidentification of environmentally persistent free radicals as molecular pollutants in particulate matter[J]. Environmental science & technology, 2010, 44(6):1933-1939.
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