Risk assessment of the ignitability and explosivity of aluminum nanopowders

Previously, an extensive study has been carried out in order to assess the ignition sensitivity and explosivity of aluminum nanopowders. It showed notably that, as the particle size decreases, minimum ignition temperature and minimum ignition energy decrease, indicating higher potential inflammation. However, the explosion severity decreases for diameters lower than 1 μm. As a consequence, this study leads to the conclusions that the ignition sensitivity and explosion severity of aluminum nanopowders may be affected by various phenomena, as pre-ignition, agglomeration/aggregation degree and the intrinsic alumina content. The presence of wall-quenching effects and the predominance of radiation compared to conduction in the flame propagation process have to be discussed to ensure the validity of the 20 L sphere and of the results extrapolation. Based on the peculiar behaviours that had been previously highlighted, a specific risk analysis has been developed in order to assess the fire and explosion risks of such materials. It has been applied to an industrial plant of aluminum nanopowders production. The hazard identification and the consequence modelling steps, especially the quantification of the likelihood and consequences, have been designed specifically. The application of this method has led to the definition of the most adequate safety barriers.     

微生物处理含油污泥主要影响因素研究

污泥含油量和微生物接种量是影响微生物去除土壤中的石油污染物效果、时间和成本的主要因素。以安塞油田地面污泥为样本,在确定污泥物理化学性质的基础上,通过试验给出了不同污泥含油量和不同微生物接种量对降解速率影响的关系曲线,根据试验结论,综合考虑处理周期和成本,确定待处理污泥的含油量上限为8%,最佳微生物接种量为6%。按此条件进行现场施工,经过100 d的降解,污泥含油量降至1%以下,达到国家环保排放标准。     

MODELKEY

The EU Water Framework Directive (WFD) requires the achievement of good ecological and chemical status in European river basins. However, evidence is increasing that a majority of European water bodies will not achieve this goal. Nutrient emissions and related eutrophication together with hydromorphological alterations have been suggested as the major driving forces of this insufficient ecological status. MODELKEY (511237 GOCE, FP6) provides strong evidence that toxic chemicals also affect the ecological status of European rivers. This was demonstrated in the case study rivers Elbe, Scheldt and Llobregat on different scales. This paper summarises key findings of MODELKEY including recommendations for WFD implementation. We ? provide evidence of toxic stress in aquatic ecosystems, ? provide evidence that impairment of ecological status results from impact of multiple stressors, ? suggest a tiered approach to assess impact of chemicals on ecological status, ? suggest a new approach for deriving candidate compounds for monitoring and prioritisation, ? call for consideration of bioavailability and bioaccumulation in chemical status assessments, ? suggest improvements for WFD water quality monitoring programmes, ? provide new integrated tools for basin-scale risk assessment and decision making, ? developed a Decision Support System to support river basin management. These key results will be presented in a series of ten integrated sections; for the scientific details please refer to publications listed on the MODELKEY website (http://www.modelkey.org/). This article also looks beyond MODELKEY and proposes a combination of MODELKEY diagnostic tools with recent ecological methods to further improve effectiveness of river basin management.     

市售绿茶自混合水溶液中吸附除去铬（Ⅵ）的研究

本文探讨了国产茶叶（市售云南产绿茶）的结构、成份和溶解，以及在不同浓度、时间、ｐＨ、温度的条件下，自混合溶液中大量吸附铬（Ⅵ）的特性。结果表明，浸泡过的茶叶对Ｃｒ（Ⅵ）的吸附率略低于未泡茶样，在一定条件下，Ｃｒ（Ⅵ）的吸附量可达到４．９６ｍｇ／ｇ。我们建议在这复杂体系中，用离子交换吸附过程形成表面配合物，以及发生化学作用的综合吸附机理来解释。     

汉江下游农村区域经济发展方向

江汉下游农村经济区在湖北省中部，经济区位居中处优，在湖北省农村经济活动中具有举足轻重的地位，该区乡镇企业较发达，特别是天门、仙桃、潜江三市尤为突出。当前我国正处于向社会市场经济转轨初期，全省处于如何实现国民经济和社会发展“九五”计划和２０１０年远景目标建议重要开端时期，为了阐明本区在“转轨”和“实现建议”时期的作用，就今后的发展方向等问题作了初步探讨，并进一步提出相应对策措施。     

Ecotoxicological evaluation of pig slurry

Swine sewage could be source of nutrients and pollutants. This work estimates the environmental risk in nine samples from different farm treatment systems based on the evaluation of their effects in Daphnia magna acute test, and on the assessment of Cu, Zn and ammonia as main contributors. NH3 and Cu were responsible for LC50 results (1-5% of dilution). Organic compounds were quantified through several extraction methods (SPMDs, SPE and solvent extraction). A more exhaustive extraction was performed in an additional sample, which showed indole and phenol recoveries much higher than the previous ones. This method also includes PCBs (430 ppb) and fatty acids (approximately =150 ppm) quantification.     

县级系统开展全民环境教育探讨

叙述环境教育的产生及发展,介绍目前环境保护及环境教育还存在的问题,讨论了开展环境教育的必要性及有利条件,及在县级开展环境教育的基本作法。     

城市绿地系统植物生态功能评价及其应用——以苏州市为例

城市绿地植物作为城市生态系统的重要组成,在改善城市生存环境和维持生态平衡方面发挥着重要作用,在城市生态系统中具有其他子系统不可替代的特殊生态功能。文章以苏州市为例,采取分层随机抽样调查的方法选取了道路、公园、居住小区共计30个具有代表性的样本区进行调查,并结合苏州市实际情况,筛选出吸硫能力、滞尘能力、抗污能力、增湿能力、环境卫生等9个评价指标,运用综合指数评价法对30个样本区中40种常见植物进行评价。结果表明苏州市绿地系统植物生长现状及其总体生态功能较好,绿化植物综合评价指数达到中等以上水平的占80％,其中乔木占所调查乔木总数的100％。文章最后对苏州市绿地系统结构优化及植物物种配置等方面提出了建议。     

浅析化学品分类及分类目录的建立

介绍了目前国际上存在的分类体系,阐述了我国化学品分类现状,评估了我国现行危险化学品名录的分类标准与GHS要求上的差异,通过研究欧盟、日本等发达国家的目录编制情况,指出目录的编制对我国实施GHS的必要性。     

热脱附／毛细管气相色谱／质谱法测定车内空气中挥发性有机物

建立了热脱附／毛细管气相色谱／质谱联用测定车内空气中苯、甲苯、乙酸丁酯、乙苯、对／间二甲苯、苯乙烯、邻二甲苯、十一烷和对二氯苯等挥发性有机物采样、分析方法。十种挥发性有机物在一定浓度范围内工作曲线线性良好,相关系数均在0．9970～0．9998之间。检出限在0．2～1．2μg/m^3。用该法检测了某汽车企业生产的轿车内的空气,取得满意结果,表明本方法具有一定的实用性、推广性。