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241.
Spectroscopic characterization of the structural and functional properties of natural organic matter fractions 总被引:31,自引:0,他引:31
Natural organic matter (NOM) is known to be complex in nature with varying structural and functional characteristics. In this study, an aquatic NOM was fractionated into the polyphenolic-rich (NOM-PP) and the carbohydrate-rich (NOM-CH) fractions in an attempt to better characterize their chemical and structural properties along with a reference soil humic acid (SHA). Various spectroscopic techniques were employed for the study, including ultraviolet-visible (UV/Vis). 13C-nuclear magnetic resonance, Fourier-transform infrared, fluorescence, and electron paramagnetic resonance spectroscopies. Results indicate that the relative abundance of aromatic C=C and methoxyl (-OCH3) functional groups are in the order of SHA > NOM-PP > NOM-CH. However, the aquatic NOM-PP and NOM-CH fractions are characterized by high contents of carboxylic and alcoholic functional groups relative to the SHA. In particular, the NOM-PP fraction appears to contain more phenolic and ketonic functional groups than the NOM-CH and SHA fractions, and it gives a strong fluorescence and high paramagnetic spin count. On the other hand, the NOM-CH fraction possesses a relatively low amount of carbon but a high amount of oxygen or oxygen-containing structural features, such as carbohydrate-OH and carboxylic groups, and shows the least fluorescence intensity and paramagnetic spin counts. Results of these spectroscopic studies confirm the heterogeneous nature of NOM, and point out the importance of isolation and improved characterization of various NOM subcomponents in order to better understand the behavior and roles of NOM in the natural environment. 相似文献
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Trace analysis of dissolved polychlorinated organic compounds in the water of the Yangtse River (Nanjing, China) 总被引:15,自引:0,他引:15
Sun C Dong Y Xu S Yao S Dai J Han S Wang L 《Environmental pollution (Barking, Essex : 1987)》2002,117(1):9-14
Eighteen organochlorine contaminants from the water samples of the Yangtse River have been qualitatively and quantitatively analyzed. The analysis of polychlorinated organic compounds (PCOCs) extracted by C18 Solid Phase Extract (SPE) was performed using HP6890 gas chromatograph coupled by ECD detector. The analytical results demonstrate that the analytical methods are reliable based on the fact that most of the recoveries for the targeted compounds are 60-90%. Most of the concerned contaminants, i.e. chlorinated pesticides and PCBs were found in the water samples of the Yangtse River, but their concentration was very low, <2.97 ng l(-1), which is far less than 1 microg l(-1)--the standard of drinking water of China. It is apparent that the PCOCs were in high concentration during the dry season, and in low concentration during the rainy season. The situation of PCOCs contamination in the water of the Yangtse River in 1999 was greatly improved in comparison with 10 years ago. 相似文献
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丝瓜对食品废水的净化功能及经济效益 总被引:14,自引:0,他引:14
本文研究了丝瓜(Luffacylindrica)在水面上的水培技术,对食品工业废水(啤酒废水)的净化功能及其经济效益。其试验结果表明:采用水培技术将丝瓜栽种在水面上是完全成功的。该法已经被应用到无锡市酿酒总厂食品工业废水净化处理。在5月份,丝瓜对啤酒废水中污染物TN的净化率为78.6%,TP78.0%,NH+_4-N99.6%,COD22.5%,浊度80.9%。在6月份,丝瓜的净化率为TN89.1%,TP90.4%,NH+_4-N99.2%,COD44.1%和浊度86.4%。由此可见,丝瓜是一种对食品废水净化的优良植物,其经济效益也很显著,每亩水面丝瓜(果实)可达2000kg~2500kg,经济价值达2000元~2500元。 相似文献
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城市室内环境多环芳烃污染与源的相关性 总被引:5,自引:0,他引:5
本实验选择了天津市4类典型室内环境和2处室外对照点,共19个采样点。现场采样测定了10种PAHs组成含量。结果显示,室内燃煤和室内吸烟是室内环境中多环芳烃排放的主要污染源。同作为对照的室外大气中多环芳烃组成和含量进行了对比,研究了室内环境不同污染源排放多环芳烃组成和含量的特征性。提出了室内燃煤污染同燃煤型室外大气源排放多环芳烃具有相似组成含量特征,而室内烟草烟雾污染源的多环芳烃组成含量特征则与室外 相似文献