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411.
Liu P Zhu D Zhang H Shi X Sun H Dang F 《Environmental pollution (Barking, Essex : 1987)》2008,156(3):1053-1060
Improved predictions on the fate of organic pollutants in surface environments require a better understanding of the underlying sorption mechanisms that control their uptake by soils. In this study, we monitored sorption of nine aromatic compounds with varying physicochemical properties (hydrophobicity, electron-donor/acceptor ability and polarity), including two polycyclic aromatic hydrocarbons, two chlorobenzenes, two nitroaromatic compounds, dichlobenil, carbaryl and 2,4-dichlorophenol in aqueous suspension of four surface soils of eastern China. The tested soils were characterized with respect to organic carbon (OC) content, black carbon content, mineralogy, morphology and size fraction to assess the role of the diverse soil characteristics in sorption. The results of this study show that not only the solute hydrophobicity and the OC content of soil are important to the retention of organic pollutants, but also the solute molecular structure and the soil nature. 相似文献
412.
水质总氮测定中的有关问题探讨 总被引:1,自引:0,他引:1
对总氮测定中的一系列影响因素,诸如实验用水,器皿的洗涤,实验室环境试剂的提纯、配制和保存,消解温度、压力和时间的控制,以及高氨氮水样中的总氮测定、总氮、总磷的同时测定和其他有关的问题,作了较为详细的探讨,并提出了相应的解决办法。 相似文献
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Zhu J Wu X Miller C Yu F Chen P Ruan R 《Journal of environmental science and health. Part. B》2007,42(4):393-401
In this paper, continuous production of hydrogen through fermentation with liquid swine manure as substrate was researched using a semi-continuously fed fermenter (8 L in total volume and 4 L in working volume). The pH and temperature for the fermenter were controlled at 5.3 +/- 0.1 and 35 +/- 1 degrees C, respectively, throughout the experiment. Three hydraulic retention times (16, 20, and 24 h) were investigated for their impact on the efficiency and performance of the fermenter in terms of hydrogen yields. The results indicate that hydraulic retention time (HRT) has a strong influence on the fermenter performance. An increasing HRT would increase the variation in hydrogen concentration in the offgas. To produce hydrogen with a fairly consistent concentration, the HRT of the fermenter should not exceed 16 h, which, however, did not appear to be short enough to control methanogenesis because the offgas still contained about 5% methane. When methane content in the offgas exceeded 2%, an inverse linear relationship between hydrogen and methane was observed with a correlation coefficient of 0.9699. To increase hydrogen content in the offgas, methane production has to be limited to below 2%. Also, keeping oxygen content in the fermenter below 1.5% would increase the hydrogen concentration to over 15%. The product to substrate ratio was found to be around 50% for the fermenter system studied, evidenced by the observation that for every 6 liters of manure fermented, 3 liters of pure hydrogen were produced, which was significant and encouraging. 相似文献
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419.
湖北水资源现状与可持续利用战略对策 总被引:11,自引:2,他引:9
湖北省有十分丰富的过境客水资源,但自产水资源却十分有限,在水资源开发利用中存在许多亟待解决的问题。如地表水污染日趋严重,地下水也存在不容的污染;农业用水占大头,其节水潜力巨大;目前主要是利用地表水,地下水的利用很少;洪涝时时灾害仍然十分严重,并有愈演愈烈的趋势;从长远看,湖北省的水资源问题将主要是污染型短缺的问题;南水北调中线工程将对汉江中下游供水和水质造成不容忽视的影响;在计划体制下形成的水资源 相似文献
420.
高架路桥的震害、震害原因及抗震措施 总被引:2,自引:0,他引:2
对近年来美、日等国的高架道路和高架桥梁所遭受到的地震破坏以及破坏原因进行了概述,对其在高架路桥的规划、设计、施工过程中所要取的抗震措施作了介绍。 相似文献