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臭氧氧化水中石油类污染物的初步研究 总被引:23,自引:0,他引:23
对石油类污染物严重污染的某市水源地下水进行了臭氧净化技术的静态试验研究,通过臭氧对石油类污染物的氧化作用,结合紫外分光光度法测定油的吸收峰曲线和色-质联机结果的分析,初步研究了臭氧氧化水中石油类污染物的过程和途径。 相似文献
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Yahui He Man Meng Woldemariam Kalekristos Yohannes Majid Khan Mengqiang Wang A. M. Abd EI-Aty 《Journal of environmental science and health. Part. B》2020,55(4):388-395
AbstractTo stipulate the rationale of spraying doses and to determine the safe interval period of boscalid suspension concentrate (SC), the degradation dynamics and residual levels were investigated in cucumber and soil using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Field trials were conducted according to Chinese Guideline on pesticide residue trials. Following application, the degradation kinetics was best ascribed to first-order kinetic models with half-life of 2.67–9.90 d in cucumber. Spraying boscalid SC at 1.5-fold the recommended dosage yield terminal residues, which are clearly lower than the maximum residue limit (MRL) established by China (MRL =5?mg.kg?1) in cucumber. At variance, the dissipation dynamics in soil did not fit to first-order kinetics and the half-life was more than 17?days, the finding which denotes that the degradation behavior of boscalid in soil proceeds slowly. It has therefore been shown that boscalid is safe for use on cucumbers under the recommended dosage. 相似文献
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S. Christensen P. Ambus J.R.M. Arah H. Clayton B. Galle D.W.T. Griffith K.J. Hargreaves L. Klenzedtsson A.-M. Lind M. Maag A. Scott U. Skiba K.A. Smith M. Welling F.G. Wienhold 《Atmospheric environment (Oxford, England : 1994)》1996,30(24):4183-4190
The soil in a drained fjord area, reclaimed for arable farming, produced N2O mainly at 75–105 cm depth, just above the ground water level. Surface emissions of N2O were measured from discrete small areas by closed and open-flow chamber methods, using gas chromatographic analysis and over larger areas by integrative methods: flux gradient (analysis by FTIR), conditional sampling (analysis by TDLAS), and eddy covariance (analysis by TDLAS). The mean emission of N2O as determined by chamber procedures during a 9-day campaign was 162–202 μg N2ONm−2h−1 from a wheat stubble and 328–467 μg N2ONm−2 h−1 from a carrot field. The integrative approaches gave N2O emissions of 149–495 μg N2ONm−2 h−1, i.e. a range similar to those determined with the chamber methods. Wind direction affected the comparison of chamber and integrative methods because of patchiness of the N2O emission over the area. When a uniform area with a single type of vegetation had a dominant effect on the N2O gradient at the sampling mast, the temporal variation in N2O emission determined by the flux gradient/FTIR method and chamber methods was very similar, with differences of only 18% or less in mean N2O emission, well below the variation encountered with the chamber methods themselves. A detailed comparison of FTIR gradient and chamber data taking into account the precise emission footprint showed good agreement. It is concluded that there was no bias between the different approaches used to measure the N2O emission and that the precision of the measurements was determined by the spatial variability of the N2O emission at the site and the variability inherent in the individual techniques. These results confirm that measurements of N2O emissions from different ecosystems obtained by the different methods can be meaningfully compared. 相似文献
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城市污水处理厂不同工艺段中有机氯农药残留 总被引:3,自引:0,他引:3
建立了基于HLB固相萃取柱和气相色谱 /电子捕获 (GC/ECD)分析城市污水中有机氯农药的分析方法 ,同时分析了北京市高碑店和北小河两个污水处理厂中 4个不同工艺段水体中有机氯农药的浓度。在两个污水处理厂的水体中共检出了 6种有机氯类农药 ,分别是α 六六六、β 六六六、γ 六六六、δ 六六六、艾氏剂和 4 ,4’ 滴滴滴 ,浓度在 1 89—6 9 6ng/L之间。结果表明 ,曝气活性污泥法对六六六类有机氯农药的去除效果较好。 相似文献