Life Cycle Assessment as Part of Sustainability Assessment for Chemicals (5 pp)

Background LCA is the only internationally standardized environmental assessment tool (ISO 14040-43) for product systems, including services and processes. The analysis is done ‘from cradle-to-grave’, i.e. over the whole life cycle. LCA is essentially a comparative method: different systems fulfilling the same function (serving the same purpose) are compared on the basis of a ‘functional unit’ - a quantitative measure of this function or purpose. It is often believed that LCA can be used for judging the (relative) sustainability of product systems. This is only partly true, however, since LCA is restricted to the environmental part of the triad ‘environment/ecology - economy - social aspects (including intergenerational fairness)’ which constitutes sustainability. Standardized assessment tools for the second and the third part are still lacking, but Life Cycle Costing (LCC) seems to be a promising candidate for the economic part. Social Life Cycle Assessment still has to be developed on the basis of known social indicators.Method and Limitations LCA is most frequently used for the comparative assessment or optimization analysis of final products. Materials and chemicals are difficult to analyse from cradle-to-grave, since they are used in many, often innumerable product systems, which all would have to be studied in detail to give a complete LCA of a particular material or substance! This complete analysis of a material or chemical is evidently only possible in such cases where one main application exists. But even if one main application does exist, e.g. in the case of surfactants (chemicals) and detergents (final products), the latter may exist in a great abundance of compositions. Therefore, chemicals and materials are better analysed ‘from cradle-to-factory gate’, leaving the analysis of the final product(s), the use phase and the ‘end-of-life’ phases to specific, full LCAs.Conclusion A comparative assessment of production processes is possible, if the chemicals (the same is true for materials) produced by different methods have exactly the same properties. In this case, the downstream phases may be considered as a ‘black box’ and left out of the assessment. Such truncated LCAs can be used for environmental comparisons, but less so for the (environmental) optimization analysis of a specific chemical: the phases considered as ‘black box’ and left out may actually be the dominant ones. A sustainability assessment should be performed at the product level and contain the results of LCC and social assessments. Equal and consistent system boundaries will have to be used for these life cycle tools which only together can fulfil the aim of assessing the sustainability of product systems.     

物理化学方法在安全评价中的应用研究

提出以本质安全与系统安全为目的,在安全评价领域中使用物理化学方法,对化工装置中化学反应过程及其他物理化学过程进行安全分析与评价,从而深入了解变化过程,提出安全对策与措施。对安全评价模式、方法进行了探索并应用到实际工作中,同时阐述了该模式中HAZOP方法、物理化学方法各自的特点。列举了物理化学方法在几个方面的应用并以一实例:催化剂制备装置的安全评价。     

DISSOLVED HEAVY METALS IN SHALLOW GROUND WATER IN A SOUTHEASTERN MICHIGAN URBAN WATERSHED1

ABSTRACT: The occurrence of dissolved heavy metal concentrations in shallow ground water were measured at 126 sites within an urban watershed in southeastern Michigan. A total of 1,140 samples were collected from the first saturated zone, and the mean concentrations of 11 heavy metals (arsenic, barium, cadmium, chromium, copper, lead, mercury, nickel, selenium, silver, and zinc) were obtained and compared to their corresponding mean concentrations within surface soil. The results suggest that former and current land use processes have resulted in significant adverse impacts on the study region. Levels of Cr 20 to 30 times the maximum contaminant level (MCL) have been detected in the ground water beneath industrial sites. In addition, Cd and Pb have been found at levels exceeding their MCLs where surface soils are clay‐rich, and in sandy soils at more than 10 times their MCLs. The high levels of Cr in ground water strongly suggest that the chromium is in a hexavalent form, and this likelihood is supported by current studies. Given the hydraulic connection between the watershed's surface waters and the Great Lakes, these findings raise significant ecological and public health concerns.     

南京近地层单点气象要素与大气细菌浓度分布规律调查研究

为了分析南京某地的气象要素和当地大气细菌浓度的分布及变化规律，探讨二之间的关系，本利用气象观测仪器和大气细菌采样仪器进行现场观测与测量，在大量气象观测数据和大气细菌采样结果基础上，分析了他们的变化规律。总体来看，南京大气细菌浓度不高，1天内气象要素及细菌浓度均呈周期变化，且二有一定的相关性。     

绿色化学与环境保护

近年来国际上较普遍提倡和开展的绿色化学与技术的研究,目的是发展环境友好技术、环境无害技术或清洁生产技术,同时强调化学过程的原子经济性,反应的高选择性,不生成或很少生成副产品或废物,实现或接近零排放过程。通过介绍国内外对绿色化学的研究进展,指出国外对绿色化学的研究主要是围绕化学反应、原料、催化剂、溶剂和产品的绿色化展开的。绿色化学的发展能节省资源、减少环境污染,并将成为可持续发展战略的核心内容。     

原油指纹识别技术

为使毛细管色谱“指纹”特征应用于污染事故的鉴定,采用分辨效能高的毛细管色谱柱及原油指纹识别技术,对江苏油田９个不同地区和来源的原油进行了分析考察,测定了油品中正构烷烃及姥鲛烷、植烷的含量。实验进一步论证了：以正构烷烃轮廓特征和姥鲛烷、植烷特征峰面积比值相结合的原油鉴别方法不受进样和色谱条件的影响,具有一定的准确性和可靠性。     

绿色化学与21世纪水处理剂发展战略

绿色化学是近年提出的新概念 ,是一门全新的从源头上彻底阻止污染的化学 ,其影响已迅速扩展到自然科学的各个学科 ,将给与化学过程有关的学科带来革命性的变化 ,成为当前和 2 1世纪的学科前沿和重点研究方向。绿色化学正在重新塑造水处理剂的发展方向 ,改变新水处理剂分子的设计思想 ,并对现有的各种水处理剂产品重新评价和设计。     

库车前陆盆地流体化学、成因与流动

库车前陆盆地寒武系 -第三系流体分析显示 :寒武系 -奥陶系和侏罗系油田水与白垩系 -第三系有所差异 ,前者总矿化度相对较低 ,为 90g/L～ 1 1 0g/L ;相对富Ca2 + 和HCO-3 ;后者总矿化度介于 73g/L～ 3 1 0g/L,主要为 1 3 0g/L～ 2 90g/L,相对富K+ +Na+ 和Cl-;而大宛齐第三系油田水则相对富Ca。影响水化学演化的因素包括 :膏盐类、沸石类矿物溶解以及白云化作用和富镁绿泥石形成等。白垩系油田水δ18O、δD关系显示为淡水蒸发成因 ,且在轮台断隆带油田水87Sr/86Sr向西降低 ,指示了富87Sr的流体来自东部的碎屑泥岩 ,这与本区煤成油运移方向是一致的。而 2个寒武系 -奥陶系油田水87Sr/86Sr高达0 .71 71 6,并富Li、B、Sr元素和δ18O ,被认为来自结晶基岩 ,与氮气、氦气及部分甲烷的来源一致。     

陆上物质的远距离输送对西太平洋热带海域降水化学组成的影响

１９８８年９－１０月在西太平洋热带海域收集了４６个雨水样品和３８８份雨水样品和３８８份雨滴谱。分析结果表明，３个ｐＨ值范围下的平均两滴谱的分布基本上满足指数递减律。在风系作用下，远距离输送来的陆上物质对该海域雨水的平均ｐＨ值为５．７３，而“陆地性”降雨的平均ｐＨ值只有４．８０。ｐＨ５．７３可认为是ＴＷＰＡ上未受陆地源直接影响的天然降雨的平均ｐＨ值。最后还给出了观测期间该海域非海化学组分的湿沉降通量     

高浓度氨氮废水处理试验

采用二级吹脱加生化的方法处理高浓度氨氮废水，试验在工况I（气、水温均为4℃）和工况Ⅱ（气温4℃，水温28℃,pH=10.5)条件下分别进行静、动态试验，结果表明在工况Ⅱ条件下，氧化铁废水（浓氨水）的静、动态试验怕氮去除率分别为82.67%和84.19%；综合废水的静、动态试验氨氮去除率一级吹脱分别为62.03%和74.16%，二级吹脱后氨氮浓度降至82.16mg/L和74.32mg/L。再接上后续的生化处理，该废水能达到规定的排放标准。