Emission of Particulate Matter 2.5 (PM2.5) from Sewage Sludge Incinerators in Japan

Because fine particulate matter ≤2.5 µm in diameter (PM2.5) causes health problems, PM2.5 emissions are of concern. However, little research on stationary sources has been conducted. To determine the concentration and filtration behavior of PM2.5, dust was collected from five fluid-bed sewage sludge incinerators (SSIs) sorted by particle size using cascade impactors. The average PM2.5 concentration was 0.00014–4.8 mg/Nm³. The total estimated amount of PM2.5 emissions from the SSIs for all plants in Japan was 0.96–8.9 tons/year. Since the SSIs with dry Electrostatic Precipitators (EP) contributed 75–99% of the total emissions, replacing dry EPs with bag filters would significantly reduce the PM2.5 emissions from SSI.     

交流高压电凝并用于铅冶炼烟尘PM_(2.5)控制

有色冶炼工业窑炉排放的PM2.5(粒径小于等于2.5μm的颗粒物)中富集铅、砷、铬、汞、铜等多种重金属元素,是空气中重金属污染物的重要贡献源。选择铅冶炼过程中产生的PM2.5作为重点控制污染物,分析其粒径特征和重金属含量,在此基础上开展交流高压电源电晕放电对细颗粒物的凝并效率研究。试验结果表明,交流高压电晕放电对于PM3.3以下的颗粒物均有明显的凝并作用,在最佳试验条件下,PM2.5的质量分数下降58%以上。该法可有效减少除尘器入口精细粉尘的含量,为有效控制冶炼烟气PM2.5排放及伴生重金属污染物的控制提供方法和工艺。     

The relationship between particulate air pollution and emergency hospital visits for hypertension in Beijing, China

Background

A number of epidemiological studies have examined the adverse effect of air pollution on mortality and morbidity. Also, several studies have investigated the associations between air pollution and specific-cause diseases including arrhythmia, myocardial infarction, and heart failure. However, little is known about the relationship between air pollution and the onset of hypertension.

Objective

To explore the risk effect of particulate matter air pollution on the emergency hospital visits (EHVs) for hypertension in Beijing, China.

Methods

We gathered data on daily EHVs for hypertension, fine particulate matter less than 2.5 μm in aerodynamic diameter (PM_2.5), particulate matter less than 10 μm in aerodynamic diameter (PM₁₀), sulfur dioxide, and nitrogen dioxide in Beijing, China during 2007. A time-stratified case-crossover design with distributed lag model was used to evaluate associations between ambient air pollutants and hypertension. Daily mean temperature and relative humidity were controlled in all models.

Results

There were 1,491 EHVs for hypertension during the study period. In single pollutant models, an increase in 10 μg/m³ in PM_2.5 and PM₁₀ was associated with EHVs for hypertension with odds ratios (overall effect of five days) of 1.084 (95% confidence interval (CI): 1.028, 1.139) and 1.060% (95% CI: 1.020, 1.101), respectively.

Conclusion

Elevated levels of ambient particulate matters are associated with an increase in EHVs for hypertension in Beijing, China.     

Spatial heterogeneity of personal exposure to airborne metals in French urban areas

The spatial distribution of urban population exposures to ambient air particles was investigated as part of the Genotox'ER study conducted in four metropolitan areas (Grenoble, Paris, Rouen and Strasbourg) in France. In each city, 60 to 90 non-smoking adult and children volunteers were selected. Subjects lived in three different urban sectors: one highly exposed to traffic emissions, one influenced by local industrial sources, and a background urban environment. The Harvard Chempass multi-pollutant personal sampler was used to sample PM10 and PM2.5 particles during 48 h during two different seasons ('hot' and 'cold'). The elemental composition of the filters was analysed by Particle-Induced X-ray Emission (PIXE). Sixteen elements were found to be over the method detection limits: Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn and Pb. The relative concentrations of elements of crustal origin (Si, Al, Ca) were higher in the coarse fraction of PM10 filters, while elements associated with combustion processes (traffic emissions or industrial combustion) presented higher relative concentrations in the PM2.5 fraction (S, Ni, V, Pb). Spatial heterogeneity of elemental exposures by urban sector is substantial for some metals of health concern, with 20% to 90% greater exposure values, on average, in the traffic proximity or industrial sectors, compared to the background sector, for Fe, Zn, Cu, V and Cr. This spatial heterogeneity should not be overlooked in epidemiological or risk assessment studies.     

超高效液相色谱-串联质谱法测定北京市区灰霾天气空气颗粒物中的全氟化合物

全氟化合物（PFCs）是全球性持久性有毒有机污染物（POPs）中危害最为严重的一类物质,而有关环境气溶胶中所含PFCs的报道却较少,尤其是北京市区灰霾天气PM2.5和PM10中PFCs含量研究未见报道。本文应用甲醇和丙酮混合溶剂提取采集的大气颗粒物样品,超高效液相色谱-串联质谱法（UPLC—MS／MS）测定颗粒物中全氟丁烷磺酸、全氟己烷磺酸、全氟辛烷磺酸、全氟辛烷酸、以及全氟十一烷酸、全氟十二烷酸、全氟十三烷酸和全氟十四烷酸等八种全氟化合物的含量。采集了2014年3月底到4月上旬北京市区北四环附近苏州街南典型的灰霾天气空气颗粒物样品。结果表明PM2.5和PM10浓度分别为73．8-260μg／m^3和219-398μg／m^3,所采集的样品中均检出PFCs,PM2.5中PFCS的总含量在13．5-115pg／m^3,平均值78．2pg／m^3,在PMl0中含量在22．2-160pg／m^3,平均值105pg／m^3,颗粒物中成分以全氟辛烷酸、全氟己烷磺酸和全氟辛烷磺酸为主。     

U-2.5%Nb合金氢化物生长动力学研究

为了探讨U-2.5%Nb(质量分数)合金的氢腐蚀行为,利用在线显微镜研究了U-2.5%Nb合金氢蚀初期氢化物的生长动力学,研究了U-2.5%Nb合金氢化初期的氢化物形貌、生长速度、氢化反应速度等之间关系。结果表明,利用在线显微镜表征氢化物的生长速度是可行的,氢化物前沿推进距离与时间呈线性关系。在一定温度范围内,氢化物的生长速度与反应温度符合Arrhenius关系,U-2.5%Nb合金氢化物生长激活能为24.34 kJ/mol。当温度增加到125℃附近时,氢化物的生长速度达到最大值,之后,随着反应温度的升高,生长速度快速下降。     

Oxide microstructure and deuterium ingress in Zr-2.5Nb CANDU® pressure tubes

Abstract

The microstructures of oxides grown on the inside surface (water-side) of Zr–2.5Nb pressure tubes removed from CANDU® reactors were characterised by TEM and correlated with deuterium ingress. Oxide cross-sections consisted of two structurally distinct regions: a columnar oxide region next to the metal/oxide interface, and an outer coarse equiaxed oxide region. Near the metal/oxide interface, the microstructure consisted of columnar grains without overt porosity. Away from the interface, the oxide consisted of coarsened equiaxed grains with (100)_m twins, grain-boundary cracks and nanopores. The oxide microstructures on various pressure tubes differ in the proportion of equiaxed grains. Electron micrographs suggest that a larger proportion of equiaxed grains is associated with higher deuterium uptake. The predominance of grain-boundary cracks in equiaxed oxides indicates that they are likely more permeable to water than columnar oxides.

Energy dispersive X-ray analyses revealed substantial amounts of Fe–K_α (and Mn–K_α) in the equiaxed oxide grains at the outermost surface. Energy Dispersive X-ray mapping of Fe–K_α and detection of the Mn-K_α (produced by neutron activation of ⁵⁴Fe and subsequent decay of ⁵⁵Fe) in the absence of external excitation, unequivocally demonstrated that the iron had accumulated in the oxide during reactor operation. The Fe concentration was highest near the outermost region, and decreased inwards towards the metal/oxide interface. These results are consistent with permeable equiaxed oxides picking up considerable amounts of Fe at the outermost region from the heavy water coolant.     

萌芽状态下的移动娱乐业

日本DoCoMoI-mode的成功,使人们感到移动娱乐业务将是移动通信的“杀手应用”。然而,WAP的挫折和失败、用户离网率的增加和ARPU值的下降,又让人们觉得依然是困难重重。目前的主要问题是,除了业务单调外,各个不同的角色还没有找准自己在价值链中的位置。虽然目前GPRS和其他2.5代技术正在快速发展,但只有等到3G设备大范围使用后,一些复杂的游戏才能推出。     

Measurement of fracture properties of Zr-2.5 Wt.% Nb pressure tube material and effect of trace impurities

This paper reports the details of a test method that uses elements of elastic-plastic fracture mechanics to assess fracture resistance of zirconium (Zr)-2.5 wt.% niobium (Nb) pressure tubes for a pressurized heavy water reactor. The fracture properties were evaluated on curved specimens, and the effect of certain trace elements on the fracture properties was determined. Significant reduction of trace impurities, produced by using four-stage melting practices rather than the conventional two-stage process, was observed to cause considerable improvement in the fracture resistance of the alloy. Scanning electron microscopy (SEM) of the fracture surfaces of the test specimens confirmed this observation.