不同来源溶解性有机质在光辐射下产生活性氧基团能力的差异
|
摘要
溶解性有机质(DOM)在光辐射下可以吸收光能产生活性氧物质(Reactive oxygen species, ROS),如单线态氧(~1O_2),羟基自由基(HO·)及激发三线态DOM(~3DOM~*)等,这些ROS对污染物的光化学反应起着重要的作用.本实验在254 nm紫外光辐射下,利用特征ROS探针化合物,探究4种不同来源土壤DOM光致产生ROS能力的差异.通过XAD-8树脂分组将2种不同来源DOM分成5个组分,进一步探究DOM结构对ROS生成的影响.研究发现,来源于黄褐土、潮土的DOM分别产生~1O_2、HO·的能力较强,而来源于黄褐土的富里酸及潮土的胡敏酸产生~3DOM~*的能力较强,说明不同来源DOM在光辐射下产生ROS的能力不同.紫外光谱分析表明,分子量较大、腐殖化程度较高的腐殖酸产生ROS的能力较强,且富里酸与胡敏酸对ROS生成的影响存在差异.整体来看,2种腐殖酸的不同分组组分对ROS生成的影响趋势相似,水与乙醇组分所产生的影响非常小,低pH值组分对ROS生成的影响比高pH值大.结合红外光谱分析,研究发现,低pH值组分的腐殖酸羧基含量较高,脂肪族官能团含量低,含氧量高,可能具有较高的光化学活性,有利于ROS的生成.此外,2种腐殖酸不同组分对ROS生成的影响存在差异,说明DOM结构中官能团的可解离程度对ROS生成具有一定影响.
Reactive oxygen species(ROS) photo-generated by dissolved organic matter(DOM) that absorbs light energy under radiation, such as singlet oxygen(~1O_2), hydroxyl radical(HO·) and excited triplet states of DOM(~3DOM~*), play important roles in the photochemical reaction of pollutants. In this experiment, the difference in ROS formation by irradiated DOM with four different sources of soil was investigated by using special probe compounds under 254 nm UV radiation. According to the XAD-8 fractionation, the DOM from two different sources was divided into five components to further explore the influence of DOM structure on ROS formation. We found that DOM derived from yellow clunamon soil and fluvo-aquic soil had stronger ability to produce ~1O_2 and HO·, respectively; while the fulvic acid derived from yellow cinnamon soil and the humic acid from fluvo-aquic soil had strong ability to produce ~3DOM~*. These results suggested that different sources of DOM had different abilities to produce ROS under light radiation. Ultraviolet spectrum analysis showed that the humic acid with higher molecular weight and higher degree of humification had stronger ability to produce ROS, and the effect between fulvic acid and humic acid on ROS formation was different. Overall, the effects of different components of the two humic acids on ROS formation were similar, the effects of water and ethanol components were negligible, and the low pH component had a greater effect on ROS formation than the high pH component. Combined with the analysis of infrared spectroscopy, we found that the low pH component had high content of carboxyl group and low content of the aliphatic functional group and, therefore, the content of oxygen was high, which had high photo-activity. In addition, there was a difference in the formation of ROS between the two components of humic acid, indicating that the dissociation degree of functional groups in DOM structure had a certain influence on ROS formation.
Reactive oxygen species(ROS) photo-generated by dissolved organic matter(DOM) that absorbs light energy under radiation, such as singlet oxygen(~1O_2), hydroxyl radical(HO·) and excited triplet states of DOM(~3DOM~*), play important roles in the photochemical reaction of pollutants. In this experiment, the difference in ROS formation by irradiated DOM with four different sources of soil was investigated by using special probe compounds under 254 nm UV radiation. According to the XAD-8 fractionation, the DOM from two different sources was divided into five components to further explore the influence of DOM structure on ROS formation. We found that DOM derived from yellow clunamon soil and fluvo-aquic soil had stronger ability to produce ~1O_2 and HO·, respectively; while the fulvic acid derived from yellow cinnamon soil and the humic acid from fluvo-aquic soil had strong ability to produce ~3DOM~*. These results suggested that different sources of DOM had different abilities to produce ROS under light radiation. Ultraviolet spectrum analysis showed that the humic acid with higher molecular weight and higher degree of humification had stronger ability to produce ROS, and the effect between fulvic acid and humic acid on ROS formation was different. Overall, the effects of different components of the two humic acids on ROS formation were similar, the effects of water and ethanol components were negligible, and the low pH component had a greater effect on ROS formation than the high pH component. Combined with the analysis of infrared spectroscopy, we found that the low pH component had high content of carboxyl group and low content of the aliphatic functional group and, therefore, the content of oxygen was high, which had high photo-activity. In addition, there was a difference in the formation of ROS between the two components of humic acid, indicating that the dissociation degree of functional groups in DOM structure had a certain influence on ROS formation.
引文
Batista A P,Teixeira A C,Cooper W J,et al.2016.Correlating the chemical and spectroscopic characteristics of natural organic matter with the photodegradation of sulfamerazine[J].Water Research,93:20-29
Cai D,Yang X,Wang S,et al.2017.Effects of dissolved organic matter derived from forest leaf litter on biodegradation of phenanthrene in aqueous phase[J].Journal of Hazardous Materials,324:516-525
Charles M.Sharpless.2012.Lifetimes of triplet dissolved natural organic matter (DOM) and the effect of nabh4 reduction on singlet oxygen quantum yields:Implications for DOM photophysics[J].Environmental Science & Technology,46(8):4466-4473
Chen J,Gu B,Leboeuf E J,et al.2002.Spectroscopic characterization of the structural and functional properties of natural organic matter fractions[J].Chemosphere,48(1):59-68
Dai J,Ran W,Xing B,et al.2006.Characterization of fulvic acid fractions obtained by sequential extractions with pH buffers,water,and ethanol from paddy soils[J].Geoderma,135:284-295
Dalrymple R M,Carfagno A K,Sharpless C M.2010.Correlations between dissolved organic matter optical properties and quantum yields of singlet oxygen and hydrogen peroxide[J].Environmental Science & Technology,44(15):5824
Dutta Majumdar R,Bliumkin L,Lane D,et al.2017.Analysis of DOM phototransformation using a looped NMR system integrated with a sunlight simulator[J].Water Research,120:64-76
Fadi A H,Davide V,Serge C,et al.2010.Reactive photoinduced species in estuarine waters.Characterization of hydroxyl radical,singlet oxygen and dissolved organic matter triplet state in natural oxidation processes[J].Photochemical & Photobiological Sciences,9(1):78-86
Fang G,Zhu C,Dionysiou D D,et al.2015.Mechanism of hydroxyl radical generation from biochar suspensions:Implications to diethyl phthalate degradation[J].Bioresource Technology,176:210-217
Fu P Q,Mostofa K M G,Wu F C,et al.2010.Excitation-emission matrix characterization of dissolved organic matter sources in two eutrophic lakes (Southwestern China Plateau)[J].Geochemical Journal Gj,44(2):99-112
Helms J R,Stubbins A,Ritchie J D,et al.2008.Absorption spectral slopes and slope ratios as indicators of molecular weight,source,and photobleaching of chromophoric dissolved organic matter[J].Limnology & Oceanography,53(3):955-969
Hodgkins S B,Tfaily M M,Podgorski D C,et al.2016.Elemental composition and optical properties reveal changes in dissolved organic matter along a permafrost thaw chronosequence in a subarctic peatland[J].Geochimica Et Cosmochimica Acta,187:123-140
何伟,白泽琳,李一龙,等.2016.溶解性有机质特性分析与来源解析的研究进展[J].环境科学学报,36(2):359-372
刘本定,李夏,代静玉.2007.XAD树脂分组水稻土富里酸组分的脂肪族特性[J].光谱学与光谱分析,27(10):2032-2037
Lester Y,Sharpless C M,Mamane H,et al.2013.Production of photo-oxidants by dissolved organic matter during UV water treatment[J].Environmental Science & Technology,47(20):11726-11733
Maizel A C,Remucal C K.2017.Molecular Composition and Photochemical Reactivity of Size-Fractionated Dissolved Organic Matter[J].Environmental Science & Technology,51(4):2113-2123
Mostafa A M,Rosario-Ortiz F I.2013.Singlet oxygen formation from wastewater organic matter[J].Evironmental Science & Technology,47(15):8179-8186
Rezaei R,Mohseni M.2016.Impact of natural organic matter on the degradation of 2,4-dichlorophenoxy acetic acid in a fluidized bed photocatalytic reactor[J].Chemical Engineering Journal,310(2):457-463
Scully N M,Cooper W J,Tranvik L J.2010.Photochemical effects on microbial activity in natural waters:the interaction of reactive oxygen species and dissolved organic matter[J].Fems Microbiology Ecology,46(3):353-357
Stevenson F J.1982.Humus chemistry:genesis,composition,reactions[J].Soil Science,135(2):129-130
Timko S A,Romera-Castillo C,Rudolf Jaffé,et al.2014.Photo-reactivity of natural dissolved organic matter from fresh to marine waters in the Florida Everglades,USA[J].Environmental Science:Processes & Impacts,16(4):866-878
Xia X,Li G,Yang Z,et al.2009.Effects of fulvic acid concentration and origin on photodegradation of polycyclic aromatic hydrocarbons in aqueous solution:Importance of active oxygen[J].Environmental Pollution,157(4):1352-1359
Xue S,Sun J,Liu Y,et al.2018.Effect of dissolved organic matter fractions on photodegradation of phenanthrene in ice[J].Journal of Hazardous Materials,361:30-36
Yabuta H,Fukushima M,Kawasaki M,et al.2008.Multiple polar components in poorly-humified humic acids stabilizing free radicals:Carboxyl and nitrogen-containing carbons[J].Organic Geochemistry,39(9):1319-1335
Yu C H,Wu C H,Lin C H,et al.2008.Hydrophobicity and molecular weight of humic substances on ultrafiltration fouling and resistance[J].Separation & Purification Technology,64(2):206-212
杨小霞,马晓冬,顾丽鹏,等.2015.DOM结构特征及其对17β-雌二醇光降解的影响[J].中国环境科学,35(5):1375-138
Zhang S,Chen J,Xie Q,et al.2011.Comment on "Effect of dissolved organic matter on the transformation of contaminants induced by excited triplet states and the hydroxyl radical"[J].Environmental Science & Technology,45(18):7945-7946
Zhu Y,Song Y,Yu H,et al.2017.Characterization of dissolved organic matter in Dongjianghu Lake by UV-visible absorption spectroscopy with multivariate analysis[J].Environmental Monitoring & Assessment,189(9):443
张玉兰,孙彩霞,陈振华,等.2010.红外光谱法测定肥料施用26年土壤的腐殖质组分特征[J].光谱学与光谱分析,30(5):1210-1213
Cai D,Yang X,Wang S,et al.2017.Effects of dissolved organic matter derived from forest leaf litter on biodegradation of phenanthrene in aqueous phase[J].Journal of Hazardous Materials,324:516-525
Charles M.Sharpless.2012.Lifetimes of triplet dissolved natural organic matter (DOM) and the effect of nabh4 reduction on singlet oxygen quantum yields:Implications for DOM photophysics[J].Environmental Science & Technology,46(8):4466-4473
Chen J,Gu B,Leboeuf E J,et al.2002.Spectroscopic characterization of the structural and functional properties of natural organic matter fractions[J].Chemosphere,48(1):59-68
Dai J,Ran W,Xing B,et al.2006.Characterization of fulvic acid fractions obtained by sequential extractions with pH buffers,water,and ethanol from paddy soils[J].Geoderma,135:284-295
Dalrymple R M,Carfagno A K,Sharpless C M.2010.Correlations between dissolved organic matter optical properties and quantum yields of singlet oxygen and hydrogen peroxide[J].Environmental Science & Technology,44(15):5824
Dutta Majumdar R,Bliumkin L,Lane D,et al.2017.Analysis of DOM phototransformation using a looped NMR system integrated with a sunlight simulator[J].Water Research,120:64-76
Fadi A H,Davide V,Serge C,et al.2010.Reactive photoinduced species in estuarine waters.Characterization of hydroxyl radical,singlet oxygen and dissolved organic matter triplet state in natural oxidation processes[J].Photochemical & Photobiological Sciences,9(1):78-86
Fang G,Zhu C,Dionysiou D D,et al.2015.Mechanism of hydroxyl radical generation from biochar suspensions:Implications to diethyl phthalate degradation[J].Bioresource Technology,176:210-217
Fu P Q,Mostofa K M G,Wu F C,et al.2010.Excitation-emission matrix characterization of dissolved organic matter sources in two eutrophic lakes (Southwestern China Plateau)[J].Geochemical Journal Gj,44(2):99-112
Helms J R,Stubbins A,Ritchie J D,et al.2008.Absorption spectral slopes and slope ratios as indicators of molecular weight,source,and photobleaching of chromophoric dissolved organic matter[J].Limnology & Oceanography,53(3):955-969
Hodgkins S B,Tfaily M M,Podgorski D C,et al.2016.Elemental composition and optical properties reveal changes in dissolved organic matter along a permafrost thaw chronosequence in a subarctic peatland[J].Geochimica Et Cosmochimica Acta,187:123-140
何伟,白泽琳,李一龙,等.2016.溶解性有机质特性分析与来源解析的研究进展[J].环境科学学报,36(2):359-372
刘本定,李夏,代静玉.2007.XAD树脂分组水稻土富里酸组分的脂肪族特性[J].光谱学与光谱分析,27(10):2032-2037
Lester Y,Sharpless C M,Mamane H,et al.2013.Production of photo-oxidants by dissolved organic matter during UV water treatment[J].Environmental Science & Technology,47(20):11726-11733
Maizel A C,Remucal C K.2017.Molecular Composition and Photochemical Reactivity of Size-Fractionated Dissolved Organic Matter[J].Environmental Science & Technology,51(4):2113-2123
Mostafa A M,Rosario-Ortiz F I.2013.Singlet oxygen formation from wastewater organic matter[J].Evironmental Science & Technology,47(15):8179-8186
Rezaei R,Mohseni M.2016.Impact of natural organic matter on the degradation of 2,4-dichlorophenoxy acetic acid in a fluidized bed photocatalytic reactor[J].Chemical Engineering Journal,310(2):457-463
Scully N M,Cooper W J,Tranvik L J.2010.Photochemical effects on microbial activity in natural waters:the interaction of reactive oxygen species and dissolved organic matter[J].Fems Microbiology Ecology,46(3):353-357
Stevenson F J.1982.Humus chemistry:genesis,composition,reactions[J].Soil Science,135(2):129-130
Timko S A,Romera-Castillo C,Rudolf Jaffé,et al.2014.Photo-reactivity of natural dissolved organic matter from fresh to marine waters in the Florida Everglades,USA[J].Environmental Science:Processes & Impacts,16(4):866-878
Xia X,Li G,Yang Z,et al.2009.Effects of fulvic acid concentration and origin on photodegradation of polycyclic aromatic hydrocarbons in aqueous solution:Importance of active oxygen[J].Environmental Pollution,157(4):1352-1359
Xue S,Sun J,Liu Y,et al.2018.Effect of dissolved organic matter fractions on photodegradation of phenanthrene in ice[J].Journal of Hazardous Materials,361:30-36
Yabuta H,Fukushima M,Kawasaki M,et al.2008.Multiple polar components in poorly-humified humic acids stabilizing free radicals:Carboxyl and nitrogen-containing carbons[J].Organic Geochemistry,39(9):1319-1335
Yu C H,Wu C H,Lin C H,et al.2008.Hydrophobicity and molecular weight of humic substances on ultrafiltration fouling and resistance[J].Separation & Purification Technology,64(2):206-212
杨小霞,马晓冬,顾丽鹏,等.2015.DOM结构特征及其对17β-雌二醇光降解的影响[J].中国环境科学,35(5):1375-138
Zhang S,Chen J,Xie Q,et al.2011.Comment on "Effect of dissolved organic matter on the transformation of contaminants induced by excited triplet states and the hydroxyl radical"[J].Environmental Science & Technology,45(18):7945-7946
Zhu Y,Song Y,Yu H,et al.2017.Characterization of dissolved organic matter in Dongjianghu Lake by UV-visible absorption spectroscopy with multivariate analysis[J].Environmental Monitoring & Assessment,189(9):443
张玉兰,孙彩霞,陈振华,等.2010.红外光谱法测定肥料施用26年土壤的腐殖质组分特征[J].光谱学与光谱分析,30(5):1210-1213