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231.
间苯二酚的微生物降解研究 总被引:4,自引:2,他引:4
从土壤中筛选的一株降解活性较高的细菌T1,当以间苯二酚为唯一碳源时,降解率可达98%,研究表明,菌体接种量的大小对间苯二酚降解速度有一定的影响;降解酶为胞内酶,经鉴定,T1菌为黄单胞菌,其某些特性与已知菌种有差异,需进一步研究。 相似文献
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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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