Adsorption of Direct Green B on mixed hydroxy-Fe-Al pillared montmorillonite with large basal spacing

Through cation-exchanging of montmorillonite, mixed hydroxy Fe-Al-pillared montmorillonites with large basal spacing were synthesized. The application of these mixed hydroxy Fe-Al-pillared montmorillonites as adsorbents in the areas of environmental protection and pollution control was investigated. Adsorption of Direct Green B, an organic dye, on OH-Fe-, OH-Al-, OH-Fe-Al- pillared montmorillonites was studied. Results showed that these pillared montmorillonites had much better adsorption properties than traditional Na-organo-montmorillonite. It was also found that pH of the solutions had great effect on the performance of these hydroxy-metal pillared montmorillonites in treating the wastewater containing Direct Green B.     

二(噁)(口英)样品制备与检测技术进展

环境中存在的二噁是一类严重影响食品安全和人类健康的强毒性有机污染物,为了能正确评价这类化合物的来源与环境中分布情况,二噁的分析检测引起了人们强烈的关注。本文介绍了样品检测前处理纯化过程中所用的各种传统的吸附剂(硅酸盐、佛罗里土和活性炭等)和新发展的几种主要吸附剂(2(1芘基)乙基二甲基硅烷化硅胶(PYE)、炭纳米管和多孔石墨炭等)的性能、在样品前处理过程中所起的作用及存在的问题和发展趋势,并在概括样品制备的基础上,阐述了二纯化技术及其检测方法(包括化学分析法和生物分析法)的进展。     

The power of simulating experiments

Addressing complex ecological research questions often requires complex empirical experiments. However, due to the logistic constraints of empirical studies there is a trade-off between the complexity of experimental designs and sample size. Here, we explore if the simulation of complex ecological experiments including stochasticity-induced variation can aid in alleviating the sample size limitation of empirical studies. One area where sample size limitations constrain empirical approaches is in studies of the above- and belowground controls of trophic structure. Based on a rule- and individual-based simulation model on the effect of above- and belowground herbivores and their enemies on plant biomass, we evaluate the reliability of biomass estimates, the probability of experimental failure in terms of missing values, and the statistical power of biomass comparisons for a range of sample sizes. As expected, we observed superior performance of setups with sample sizes typical of simulations (n = 1000) as compared to empirical experiments (n = 10). At low sample sizes, simulated standard errors were smaller than expected from statistical theory, indicating that stochastic simulation models may be required in those cases where it is not possible to perform pilot studies for determining sample sizes. To avoid experimental failure, a sample size of n = 30 was required. In conclusion, we propose that the standard tool box of any ecologist should comprise a combination of simulation and empirical approaches to benefit from the realism of empirical experiments as well as the statistical power of simulations.     

Faecal elimination of cypermethrin by cows after pour-on administration: Determining concentrations and measuring the impact on dung beetles

Cattle treatment with antiparasitic drugs is associated with an important risk exposure for dung beetles. Previous studies demonstrated the impact of some avermectin and pyrethroid compounds on several species such as Onthophagus gazella and Neomyia cornicina. However, little information is available regarding the elimination of these compounds in faeces 8 days after a pour-on administration in dairy cows. The present study, utilising a dairy cow model with cypermethrin treatment, demonstrated that concentrations in dry faeces can reach levels of 5?mg?kg^?1 between the first and fourth day after treatment and were present up to 3 months after a single dose of administration at a concentration around 10?µg?kg^?1. Faecal samples were purified with three successive columns (silica gel, anion exchange phase, and basic alumina) and analysed by GC-MS. The limit of quantification of this method was 0.5?µg?kg^?1. The high sensitivity of the method permitted one to see that the risk exposure of cypermethrin to dung beetles is longer than what was noted in the literature. According to other studies, repeated treatment with such agents may lead to the local extinction of dung beetles. Even if the impact of pyrethroid largely depends on the conditions of the ecosystem where the treated cattle are living, adverse effects of these agents may still occur.     

The ecosystem of the bay of Mali Ston natural and anthropogenic influence

Chemical hydrography, nutrients and trace metals in water, sediments and marine organisms were studied in the Bay of Mali Ston and their role in terms of pollution discussed. Results show that the entire study area is very strongly affected by the adjacent land. The overall area is well aerated so that no dangerous accumulation of nutrients with oxygen content reduction was recorded.

Results of analyses of trace metals show that the water and sediments of the bay contain high levels of some metals significantly higher than those from the open sea. This may be attributed to the natural sedimentation processes and the Neretva River and submarine spring runoffs carrying constituents of ignous and limestone rocks.     

北京西站应急管理现状及对策

从2006年春运期间北京西站发生的大规模旅客滞留事件入手,通过对事件发生的原因、发生过程以及事件发生过程中管理者应对突发事件的措施详细分析,以及对北京西站现有应急管理措施的总结,指出北京西站在应急管理中存在的主要问题。首先缺乏持续全面的风险评估工作,其次应对新的突发事件中准备不足,再次应急管理的中心环节应急响应过程中措施不得力,再次之是恢复阶段工作重点不突出。针对暴露出的问题给出提高西站应急管理能力的几点建议,建立长期动态的风险评估机制,加强铁路与地方的协调合作,加快对硬件设施的改造,以及完善应急预案和加强培训、应急演练等解决措施。     

不同水热炭化条件处理青霉素菌渣制备生物炭

为了考察不同水热炭化条件处理青霉素菌渣制备的生物炭特征,采用菌渣中分别添加氯化钠、柠檬酸和硝酸铁为添加剂和分别设置不同温度的方法,分析不同温度、不同添加剂对水热炭化产物特征的影响。结果表明, 在210 ℃时,各种样品的干重产率较高。对于水热产物结构,RNa温度最佳为210 ℃;RAc和RFe最佳温度为180 ℃。在180 ℃时,RH产物孔径平均当量直径最大为3.61 μm;RNa、RAc、RFe变化不大,分别为3.08、3和3.16 μm,变化幅度小于0.2 μm;在210 ℃时,对照产物孔径平均当量直径大于180 ℃时产物为3.94 μm;而RNa为2.99 μm,RAc、RFe孔径依次减小,为别为2.33 μm和1.84 μm。添加剂对产物孔径平均当量直径有影响,而添加剂种类影响不大;温度变化对RNa产物孔径平均当量直径影响不大,对RFe产物影响最明显。     

Review of the progress in preparing nano TiO2: An important environmental engineering material

TiO2 nanomaterial is promising with its high potential and outstanding performance in photocatalytic environmental applications, such as CO2 conversion, water treatment, and air quality control. For many of these applications, the particle size, crystal structure and phase,porosity, and surface area influence the activity of TiO2 dramatically. TiO2 nanomaterials with special structures and morphologies, such as nanospheres, nanowires, nanotubes, nanorods,and nanoflowers are thus synthesized due to their desired characteristics. With an emphasis on the different morphologies of TiO2 and the influence factors in the synthesis, this review summarizes fourteen TiO2 preparation methods, such as the sol–gel method, solvothermal method, and reverse micelle method. The TiO2 formation mechanisms, the advantages and disadvantages of the preparation methods, and the photocatalytic environmental application examples are proposed as well.     

萃取技术在环境样品处理中的运用

环境监测中环境样品的处理是非常重要的环节。环境样品成分复杂,干扰物质较多,组分的含量较低。传统的萃取方法耗时、耗能、试刘用量大、产生交叉污染,而且操作步骤繁琐。近年来,一些高效萃取技术在环境样品的处理中相继成功运用,为萃取技术的发展提供了广阔的空间。     

某定向钻工程中泥浆的配制及注意事项

介绍了某定向钻工程中黏土层、细砂中砂层、粉砂合砾地层泥浆的配制工艺及斜孔段、水平孔段、扩孔段、回拖段施工过程泥浆性能的调整方法。简述了该穿越工程泥浆的混配、回收及处理应注意的若干事项。实践表明,该水平定向钻穿越工程施工质量较好,其安全与环保工作也较为理想。