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91.
The study was undertaken to evaluate the environmental exposure to polycyclic aromatic hydrocarbons in subjects living in the area of recycling electronic garbage in Southern China and research the influence of environment smoke tobacco (EST) to people through active and passive smoking. Urinary concentrations of 2-hydroxynaphthalene, 2-hydoxyfluorene, 9-hydroxyphenanthrene, and 1-hydroxypyrene were determined in 141 randomly selected voluntary residents aged 13 to 81 years in two polycyclic aromatic hydrocarbon (PAH)-exposed groups, two control groups, and an EST research group. The concentrations of 2-hydroxynaphthalene, 2-hydoxyfluorene, 9-hydroxyphenanthrene, and 1-hydroxypyrene in PAH-exposed groups are significantly higher (p?PAHs (PAHm) are significantly elevated through active and passive smoking, while the influence of EST to other PAHm is not statistically significant. 2-Hydroxynaphthalene, 2-hydoxyfluorene, 9-hydroxyphenanthrene, and 1-hydroxypyrene in the urine of smokers are, respectively, 3.9, 1.9, 1.4, and 1.9 times to those of nonsmokers. In nonsmokers, passive smokers excreted 1.1, 1.5, 1.9, and 1.5 times of 2-hydroxynaphthalene, 2-hydoxyfluorene, 9-hydroxyphenanthrene, and 1-hydroxypyrene compared to nonpassive smokers.  相似文献   
92.
Abstract

A fluorescent method for the determination of rhodamine B (RhB) and brilliant sulfaflavine (BSF) dual tracers on cotton string collectors and in spray tank solutions was developed for the evaluation of the effects of adjuvants on the atmospheric drift of agricultural sprays. Both tracers on collectors were extracted with deionized water simultaneously and measured directly with a Fluorescent Specrometer by switching the maximum excitation and emission wavelengths. The linear ranges of the RhB and BSF standard curves were 0–50 and 0–10 ppb respectively. Recoveries of tracers on cotton strings ranged from 92.9% ± 1.1% to 95.1% ± 1.0% for RhB and 91.9% ± 2.8% to 103% ± 0.6% for BSF when spiked levels ranged from 0.25 to 2.5 μg per collector. The detection limit of the instrument was approximately 0.1 ppb for both tracers. The detection limits of the analytical method were approximately 0.1 ppb for RhB and 0.3 ppb for BSF when the background levels of cotton strings were subtracted. The presence of one tracer in the solution did not significantly interfere with the detection of the other tracer in the same solution. The presence of adjuvants added to the spray tank solutions did not interfere with the detection of both tracers when the adjuvants were applied at the manufacturer's maximum recommendation rates.  相似文献   
93.
The interactions between metals (Ca2+ and Hg2+) and extracellular polymeric substances (EPS) extracted from the aerobic and anaerobic sludge in wastewater treatment reactors were investigated using a combination of zeta potential measurement and 3-dimensional excitation–emission matrix (EEM) fluorescence spectroscopy with parallel factor (PARAFAC) analysis. Results show that Ca2+ had no substantial effects on the EEM fluorescence spectra of the EPS, but their zeta potentials increased with the increasing Ca2+ dosage. However, Hg2+ had a significant effect on the EEM fluorescence spectra of the EPS, while their zeta potentials seemed not to be affected by the dose of Hg2+. The interactions between Hg2+ and EPS were elucidated using the fluorescence quenching with PARAFAC analysis, while the interactions between Ca2+ and EPS were evaluated by the zeta potential technique. The binding constants for Hg2+ and EPS were two orders of magnitude higher than those for Ca2+ and EPS, suggesting that the binding mechanisms between Ca2+ and EPS were different from those between Hg2+ and EPS. The results might be useful for understanding the roles of EPS in bacterial self-protection against heavy metals and the aggregate formation mechanisms through ionic bridging interactions.  相似文献   
94.
诺氟沙星作为一种抗生素广泛应用于人类日常生活,并大量进入水体环境,给水环境质量和生态系统安全带来隐患。研究了由3种不同填料组成的水平流和复合垂直流生物活性滤床对诺氟沙星的去除效果,结果表明,在水力负荷为0.1m^3/(m^2·d)、进水诺氟沙星浓度为392.11—686.17μg/L(平均浓度为500.97μg/L)条件下,复合垂直流滤床对诺氟沙星去除效果普遍好于水平潜流滤床,以沸石为填料的复合垂直流生物活性滤床对诺氟沙星的去除效果最好,平均去除率为80.61%,说明选择合适填料和合适类型的生物活性滤床可以作为去除诺氟沙星的一种有效方法。  相似文献   
95.
脱硫石膏粒径分布与脱水性能实验研究   总被引:1,自引:0,他引:1  
脱硫石膏粒径分布是影响脱硫石膏浆液脱水性能的重要因素之一,以干法、湿法筛分和研磨破碎获得不同粒径分布的脱硫石膏,在相同的过滤条件下,对不同粒径分布脱硫石膏浆液脱水性能进行了研究,实验结果表明,当脱硫石膏粒径d50大于50μm且(d90-d10)小于100μm,真空过滤最大真空度不低于0.098MPa,过滤时间不少于2.5min,滤饼厚度不超过20mm时,石膏滤饼含水率可以降低到12%以下(最低可达10%);d50在17μm为脱硫石膏在相同的过滤条件下能够实现真空脱水干燥的转折点;d50和(d90-d10)共同影响石膏脱水性能,d50小于20μm时,仅表现为d50的影响。  相似文献   
96.
关于行驶中的车辆在交通系统各因素作用下的行驶安全性评价,在现有交通系统四大要素的基础上加入车辆行驶状态,构成"人-车-环境-路-车辆行驶状态"5要素。并对各要素评价指标的选定做了细致的筛选,建立了车辆行驶安全性评价指标体系。其中"人-车-环境-路"因素采用打分的形式确定其参数的分值,并利用层次分析法(AHP)计算各参数权重来构建模型的;"车辆行驶状态"因素则是引入加速度干扰的定义,建立基于道路结构的加速度干扰模型。最后,运用层级分析法建立了总的车辆行驶安全评价模型。  相似文献   
97.
资源综合利用直接影响我国可持续发展战略的实现。我国资源型企业在资源开发利用过程中存在大量的浪费现象。运用演化博弈理论分析企业群体策略的选择和演化路径,揭示企业资源效率管理行为的内在机理。研究表明治理收益、治理成本、治理风险是企业资源保护行为系统演化的重要参数,企业群体选择策略的相对适应性取决于对方企业是否治理及企业自身治理的收益与成本,演化稳定状态不仅依赖于博弈双方的学习速度和方向,也取决于博弈双方的初始状态。政府应该根据上述机理和资源型企业现实状况,制定相应的政策。  相似文献   
98.
In this study, the occurrence and distribution of polycyclic aromatic hydrocarbons (PAHs) were investigated in six sludge samples collected from Guangdong Province, China. Concentrations of PAHs varying from 2,534.1 to 6,926.6 μg kg???1 (dry sludge) were observed in three municipal wastewater treatment plants with phenanthrene (Phe), fluoranthene, and pyrene being the main compounds. In addition, 682.6 μg kg???1 PAHs were detected in one sludge sample from a food processing plant, with fluorene, Phe, and chrysene being the main components. No PAHs were detected in sludge samples obtained from two cosmetic plants. The levels and distributional characteristics of PAHs, polychlorinated biphenyls (PCBs), and polycyclic musks (PMs) from the samples were also compared. The results of this comparison indicated that petrochemical refineries and road traffic played important roles in the PAH loads in sludge, while PMs primarily originated from domestic wastewater and industrial wastewater from cosmetic plants. Finally, the presence of 98.8 μg kg???1 PCBs in sludge suggested diffusional emission sources from electrical components containing PCBs.  相似文献   
99.
Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) in surface sediment samples from Taihu Lake--an important water supply of the Yangtze River Delta, China--were investigated in the present study. Concentrations of PCDD/Fs ranged from 0.91 to 4.8 pg TEQ g(-1) dw (mean: 2.9 pg TEQ g(-1) dw, TEQ: Toxic Equivalent), which were all higher than the threshold effect level established by interim sediment quality guidelines in Canada (0.85 pg TEQ g(-1) dw). The levels of PBDD/Fs ranged from 0.16 to 1.6 pg TEQ g(-1) dw (mean: 0.52 pg TEQ g(-1) dw) and accounted for 5-33% (mean: 14%) of the total PCDD/Fs and PBDD/Fs TEQ. Comparatively, the abundance of sedimentary PCDD/Fs in the three regions (Meiliang Bay, Gonghu Bay, and Xukou Bay) showed a decreasing trend from the inflow region to the outflow region, while no significant difference was observed among their 2,3,7,8-PBDD/Fs levels, which suggested that the sources of PCDD/Fs and PBDD/Fs differed in this area. Principal component analysis suggested that the historical production/usage of pentachlorophenol and sodium pentachlorophenate was the dominant source of PCDD/Fs in the sediment of these regions. Although the specific sources of PBDD/Fs in the sediment of Taihu Lake were unclear, it was suspected to be due to atmospheric deposition; however, an additional study is needed to confirm this.  相似文献   
100.
利用植物对生态环境进行监测能综合地判断生态环境变化情况。通过对黔北丹霞地貌区、香纸沟喀斯特地貌区及烂泥沟卡林型金矿区苔类、角苔类植物的比较研究,统计分析种群的分布情况。结果表明,角苔类植物主要生长于生态环境保护较好的区域,扁萼苔科、角苔科为生态环境保护较好区域监测指示科植物,蛇苔属为生态环境保护较好区域监测指示属植物,小蛇苔、蛇苔为生态环境保护较好区域监测指示种植物。  相似文献   
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