高铁酸盐(Fe(Ⅵ))氧化去除水中PPCPs的研究进展

药物和个人护理用品(PPCPs)采用传统的污水处理方法不易去除,高铁酸盐(Fe(VI))因具有强氧化性,且氧化产物Fe(III)具有絮凝作用,近年来被广泛应用于去除PPCPs。介绍了Fe(VI)近年来的制备进展,分析了Fe(VI)去除PPCPs的效率及影响因素,探讨了Fe(VI)与PPCPs的反应机理及产物、中间产物的毒性变化,并展望了未来Fe(VI)去除PPCPs的研究方向。Fe(VI)能有效去除多种PPCPs,去除效率受p H值、温度、Fe(VI)初始浓度和PPCPs性质影响,Fe(VI)与PPCPs反应的中间产物毒性值得关注。     

二氧化氯在中水回用作电厂循环水中的杀菌特点

分析了中水作为电厂循环冷却水的特点,对比了Cl2和ClO2对此类水体的杀菌特点,分析了ClO2在硝化菌类存在下的化学变化。在总结实际应用效果的基础上,肯定了ClO2在中水回用作电厂循环水中有独到的杀菌作用。     

安规实验室仪器期间核查基本方法研究

本文介绍期间核查的作用,要素,结果的判定,从而认识安规实验室仪器期间核查的基本方法与意义,对安规实验室仪器的期间核查的运用有进一步了解和帮助。     

苯系物光催化开环降解产物低级醛类的健康效应

采用连续流配气系统,利用氮掺杂TiO2,在UV(4 W,254 nm)光照下光催化降解(PCO)室内甲苯和苯甲醛污染物,运用质子转移反应质谱仪实时检测气相中间产物,应用健康风险评估模型分析甲苯、苯甲醛光催化降解过程的健康效应.结果表明,甲苯和苯甲醛转化率和矿化率较高,但如乙醛和甲醛等低级醛类(VAs)中间产物形成潜在的健康风险,常规的转化率和矿化率指标不能全面表征苯系物的光催化过程的健康风险.乙醛极易在气相积累,是影响健康风险变化的关键;甲醛的摩尔分数稳定在较低水平,但其影响不可忽视.甲苯和苯甲醛降解过程的健康风险指数增大因子(η)随VAs积累而增大,最大值分别为8 499.68和21.43,VAs的贡献率为99.3%和98.3%;光催化降解稳定后η分别为236.09和2.30,VAs的贡献率为97.9%和97.8%;η平均值(30 min)分别为932.86和8.52,VAs的贡献率为98.5%和98.0%.由此提出了以低级醛类健康风险指数增大因子贡献值(ηVAs)表征苯系物光催化安全降解过程的特征评价指标.     

Intra-industry trade in intermediate products, pollution and internationally increasing returns

This paper examines the relationship between intra-industry trade in intermediate products, pollution and increasing returns. We develop a two-country model in which production occurs in two stages, final and intermediate good production. Intermediate goods are produced under monopolistic competition and final good production exhibits increasing returns with respect to the number of varieties of intermediates. Pollution occurs in the production of the final good when polluting intermediates are used. We analyze the effects of international trade in intermediate products on pollution, output and welfare under an endogenous tax scenario and with two types of pollution functions. The results show that, because of increasing returns, international trade either leads to lower total pollution in each country or lower pollution per unit of output in at least one country. In addition, intra-industry trade causes countries to import the environmental quality of their trading partners.     

An approach to uncertainty estimation in determining polycyclic aromatic hydrocarbons in fuel-contaminated soils

An estimation of uncertainty contribution in the entire set of the analytical data of polycyclic aromatic hydrocarbons (PAHs) in soil during a full year is presented. The analyses were performed as part of a project devoted to the assessment of the natural attenuation of selected PAHs in agricultural soil contaminated by a fuel spill. In particular, we investigated the effect of natural attenuation on the PAH dissipation rate in plots of two types of scenarios in agricultural soils. One of them was previously affected by an accidental fuel spill 10 years ago, and the other one was non-affected. The major components for estimating uncertainty contributions have been evaluated based on intermediate precision from different levels of PAH mass fraction, sample locations, and long term data set. An analysis of variance (ANOVA) test was applied to the mass fractions of clean or blank soil sub-samples versus contaminated soil sub-samples for grouping comparable data. Variables of influence in this study were site, month, and lysimeter of sampling (referring to a stainless steel box, with side lengths of 50 cm). Study sites or the spatial arrangement of lysimeter showed a clear effect in sub-sample results with the lowest mass fraction levels for heavier PAH, while monthly sampling was the variable of most significant influence for the more strongly contaminated sub-sample results.

Finally, the results of the PAH mass fractions in contaminated soil sub-samples indicated a monthly variation for which lighter, volatile PAHs rapidly decreased while the less volatile did not change.     

受载复合煤岩变形破裂电磁辐射中频信号规律试验研究

采用自主研制的电磁辐射采集系统,深入研究受载复合煤岩变形破裂电磁辐射中频信号特性。在前置部分的天线和电缆之间加入巴伦,把从振子流过电缆屏蔽层外皮的高频电流截断,减小信号的传输损耗,提取电磁辐射信号,分析其在加载各个阶段的分布规律和特征。结果表明:复合煤岩受载破裂释放的电磁辐射能量主要集中于500 kHz～1 MHz中频段,电磁辐射信号整体与应力相关性较高,相关系数大于0.8。     

Remediation of soil heavily polluted with polychlorinated biphenyls using a low-temperature plasma technique

Polychlorinated biphenyls （PCBs） were removed by low-temperature plasma technique （dielectric barrier discharge） from heavily polluted soil and their intermediate products were analyzed. The removal rate ranged from 40.1 to 84.6% by different treatments, and they were also influenced significantly （P 〈 0.01） by soil particle-size, electric power, gas flow rate and reaction time. The optimal reaction conditions of PCB removal from the soil were obtained experimentally when soil particle-size, electrical power, flow rate and reaction time were 5-10mm, 21w, 120mL. rain and 90rain, respectively. However, decreasing electrical power, flow rate and reaction time to 18 w, 60 mL. min- and 60 min respectively were also acceptable in view of the cost of remediation. This technique was characterized by the additional advantage of thorough oxidation of PCBs in the soil, with no formation of intermediate products after reaction. The technique therefore shows some promise for application in the remediation of soils contaminated with persistent organic pollutants in brown field sites in urban areas.     

考虑中间主应力对圆形巷道Hoek Brown准则解的影响

为了建立更加适用于深部巷道围岩塑性解分析的Hoek Brown准则,获得更加准确的巷道围岩塑性区范围及其支护变形量。通过将洛德参数表示的中间主应力带入Hoek Brown准则中,经过理论公式的推导,获得巷道围岩塑性区的应力和半径以及巷道周边位移的解析解。经算例分析,随着中间主应力的减小,塑性区范围也减小,当中间主应力趋近于第三主应力时,塑性区范围为最小;并且支护阻力和原岩应力对巷道塑性区范围也有一定影响;最后将计算的结果与Mohr-Coulomb准则对应的卡斯特纳解进行比较,发现文中建立的Hoek Brown强度准则更加适用于深部巷道塑性区分析。由此可知考虑中间主应力的Hoek Brown强度准则,更能全面分析巷道围岩塑性区的范围,获得更为准确的结果;在工程实践中,在易破坏的地段取地应力值时,应适当的增大中间主应力的取值,并且刚开挖巷道应及时支护,这样可有效的维护巷道围岩的稳定。     

灾害间接经济损失的计量

本文研究了三种灾害间接经济损失的计量，即间接停减产损失、中间投入积压增加损失和投资溢价损失。利用了城市投入──产出表所表达的产业关联关系估计了由于生产的联锁性造成灾害的进一步损失。并用上海市的实际数据对地震的间接经济损失作了预测计量。