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331.
Occurrence and source analysis of typical veterinary antibiotics in manure, soil, vegetables and groundwater from organic vegetable bases, northern China 总被引:19,自引:0,他引:19
The residue of antibiotics is becoming an intractable environmental problem in many organic vegetable bases. However, their residual levels and distribution are still obscure. This work systematically analyzed the occurrence and migration of typical veterinary antibiotics in organic vegetable bases, northern China. The results showed that there was no obvious geographical difference in antibiotic distribution between soil and manure. A simple migration model can be easy and quick to predict the accumulation of antibiotics in soil. Antibiotics were mainly taken up through water transport and passive absorption in vegetables. The distribution of antibiotics in a plant was in the sequence leaf > stem > root, and performed biological accumulation. The residues of antibiotics in all samples in winter were significantly higher than those in summer. Overall, this work can lay the foundation for understanding ecological risk of antibiotics and their potential adverse effects on human health by food chain. 相似文献
332.
Hong-Wen Gao Jing Lin Wei-Ying Li Zhang-Jun Hu Ya-Lei Zhang 《Environmental science and pollution research international》2010,17(1):78-83
Purpose
Owing to the present complexity and difficulty of concentrated dye wastewater treatment, this work aimed to synthesize a reproducible waste-sorbing material for the treatment of wastewater by forming the dye-conjugating complex hybrid.Methods
The inorganic/organic hybridization was applied to prepare the objective material by immobilizing waster dye-Mordant blue 9 (MB) with barium sulfate (BaSO4). The composition and pattern of the formed material were determined by spectrometry and characterized by SEM and XRD, and their formation process was clarified. The adsorption of cationic dye-basic blue BO (BB) and copper ion was investigated..Results
The hybrid of MB alone into growing BaSO4 formed the pineapple-like particles while that of the MB/BB-conjugating complex was the rhombus material. The adsorption of BB on the MB–BaSO4 hybrid was probably attributed to ion-pair equilibrium and that of Cu2+ may result from the complexation. The treatment of dye and heavy metal wastewaters indicated that the MB hybrid material removed 99.8% BB and 97% Cu2+ and the dye-conjugating hybrid with growing BaSO4 100% MB, 99.5% BB, and 44% Cu2+.Conclusion
The waste MB–BaSO4 hybrid material is efficient to treat cationic dye and Cu2+ wastewater. The dye-conjugating hybridization method is the first to be advanced for in situ wastewater treatment, and it showed a combined effect for the removal of both organic dyes and heavy metals. 相似文献333.
Mark Hixson Abdullah Mahmud Jianlin Hu Song Bai Debbie A. Niemeier Susan L. Handy Shengyi Gao Jay R. Lund Dana Coe Sullivan Michael J. Kleeman 《Atmospheric environment (Oxford, England : 1994)》2010,44(4):552-562
Future air pollution emissions in the year 2030 were estimated for the San Joaquin Valley (SJV) in central California using a combined system of land use, mobile, off-road, stationary, area, and biogenic emissions models. Four scenarios were developed that use different assumptions about the density of development and level of investment in transportation infrastructure to accommodate the expected doubling of the SJV population in the next 20 years. Scenario 1 reflects current land-use patterns and infrastructure while scenario 2 encouraged compact urban footprints including redevelopment of existing urban centers and investments in transit. Scenario 3 allowed sprawling development in the SJV with reduced population density in existing urban centers and construction of all planned freeways. Scenario 4 followed currently adopted land use and transportation plans for the SJV. The air quality resulting from these urban development scenarios was evaluated using meteorology from a winter stagnation event that occurred on December 15th, 2000 to January 7th 2001. Predicted base-case PM2.5 mass concentrations within the region exceeded 35 μg m?3 over the 22-day episode. Compact growth reduced the PM2.5 concentrations by ~1 μg m?3 relative to the base-case over most of the SJV with the exception of increases (~1 μg m?3) in urban centers driven by increased concentrations of elemental carbon (EC) and organic carbon (OC). Low-density development increased the PM2.5 concentrations by 1–4 μg m?3 over most of the region, with decreases (0.5–2 μg m?3) around urban areas. Population-weighted average PM2.5 concentrations were very similar for all development scenarios ranging between 16 and 17.4 μg m?3. Exposure to primary PM components such as EC and OC increased 10–15% for high density development scenarios and decreased by 11–19% for low-density scenarios. Patterns for secondary PM components such as nitrate and ammonium ion were almost exactly reversed, with a 10% increase under low-density development and a 5% decrease under high density development. The increased human exposure to primary pollutants such as EC and OC could be predicted using a simplified analysis of population-weighted primary emissions. Regional planning agencies should develop thresholds of population-weighted primary emissions exposure to guide the development of growth plans. This metric will allow them to actively reduce the potential negative impacts of compact growth while preserving the benefits. 相似文献
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335.
X.X. Zhang P.J. Shi L.Y. Liu Y. Tang H.W. Cao X.N. Zhang X. Hu L.L. Guo Y.L. Lue Z.Q. Qu Z.J. Jia Y.Y. Yang 《Atmospheric environment (Oxford, England : 1994)》2010,44(13):1641-1648
Based on environmental monitoring data in 93 major cities and meteorological records at 398 weather stations in China from 1981 to 2007, total suspended particle (TSP) concentration, the intensity of dustfall, and sand and dust storm frequency (Fd) were analysed. During the past 27 years, the annual average TSP concentration (CTSP) in 93 cities was 402 μg m?3. Annual average CTSP decreased from the north to the south and from inland to the coast areas with a peak value of 628.8 μg m?3 in Lanzhou. In the 1980s, 1990s and 2000s, annual average CTSP was 628.7, 319.2, and 250.1 μg m?3, respectively. Annual average intensity of dustfall (Id) was 240.5 t km?2 a?1, decreased from northern to southern China and from inland to the coast areas with the maximum value of 717.2 t km?2 a?1 in Baotou. In the 1980s, 1990s and 2000s, annual average Id was 334.8, 220.9, 146 t km?2 a?1 respectively. Annual average Id in the Loess Plateau region was commonly higher than 200 t km?2 a?1. The annual average Fd decreased from arid regions in northwestern China to humid areas in southeastern China with two sand and sand storm centers existing in Xinjiang Taklamakan Desert and western Inner Mongolia. The annual average Fd in the 1980s, 1990s, 2000s was 16, 8, 6 days respectively, decreased steadily from 18 days in 1981–5 days in 2007. Annual average Id had a positive linear relation to annual average CTSP (R2 = 0.96). Annual average Fd had a positive relation with annual average CTSP (R2 = 0.97) as well as annual average Id (R2 = 0.94). TSP was the chief pollutant influencing Air Pollution Index (API) in northern China in spring and winter seasons. Sand and dust storm might be a major factor affecting the temporal variability and spatial distribution of TSP and dustfall in China. 相似文献
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指出了Ⅱ系统烧结机机尾CSF型收尘系统投入使用以来存在的问题 ,并对存在的问题作了详细分析 ,最后针对问题提出了相应的改进措施 相似文献
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340.
利用微型滴定法测定白醋中的总酸度,并对常量实验和微型实验的测定结果进行了比较分析。结果两种方法无显著性差异,F检验、t检验均在允许范围内,微型实验的准确度和精密度均达到常量实验的测定水平,完全满足化学分析要求,并且有效地节省了实验试剂,大大降低了实验成本。 相似文献