大同市秋季大气气溶胶化学成分及来源解析

采集了大同市2004年9月大气颗粒物样品,应用外束质子激发X荧光(PIXE)方法分析得到了20种元素浓度谱分布。分析结果表明:大气颗粒物样品中绝大多数元素的浓度较低,多数元素呈粗粒模态分布;大同市秋季颗粒物污染较轻。富集因子分析结果表明,大同市秋季大气中颗粒物主要来源于源燃煤尘、土壤尘和工业排放源。     

开封大气扬尘颗粒物的来源解析

为了解析河南省开封市大气扬尘颗粒物的来源,对开封市的扬尘源成分谱和大气颗粒物PM_(10)进行采样,提取城市扬尘源中各单一源类的标识物,分析PM_(10)化学组分,应用化学质量平衡模型(CMB)和二重源解析技术进行定性和定量分析。结果表明:开封市PM_(10)污染严重,主要是城市扬尘,对环境空气中颗粒物的贡献在27. 7%,是首要污染因素;二次颗粒物对PM_(10)的贡献率达到26. 92%;汽车尾气尘对PM_(10)的贡献率在11. 29%。     

燃煤电厂烟气中Hg的生成、治理、测试及排放特征研究

燃煤电厂是大气Hg排放的主要来源之一，基于文献调研，分析了燃煤电厂烟气中Hg的来源及生成、燃烧后现有设备协同脱Hg技术和吸附剂喷射脱Hg技术、主要离线测试方法、超低排放实施前后燃煤电厂烟气Hg排放特征等，指出燃煤电厂实施更严格的烟气Hg排放控制是非常有必要的，且改性活性炭、改性飞灰喷射脱Hg技术将是未来应对更严格Hg排放限值的主流技术。研究结果可为燃煤电厂烟气Hg排放控制提供参考。     

大气中颗粒物污染来源分析

大气颗粒物污染源是指向大气环境排放有害物质或对大气环境产生有害影响的场所,设备和装置。按污染物质的来源可分为天然污染源和人为污染源。文章通过对大气中颗粒物分类进行了分类,在此基础上讨论了大气中颗粒物污染来源分析,并对大气中颗粒物污染的危害进行了研究。     

长春市2006—2007年采暖期大气降尘来源研究

研究长春市2006—2007年采暖期大气降尘的来源,采用电感耦合等离子体法分析降尘中的元素组成,应用富集因子法分析大气降尘中各元素的来源,应用化学质量平衡法分析各污染源的特征元素。结果表明:大气降尘样品中主要元素有As、Mn、Ca、Mg、Fe、Ti、Al、Pb、Zn和Cu;采暖期间长春市区的大气降尘首要来源是燃煤尘,其次是土壤风沙尘;降尘中各污染源特征元素是,建筑尘为Ca元素,土壤风沙尘为Al元素,机动车尾气尘为Pb、Zn元素,燃煤尘为Ti、Mn元素,道路尘为Fe元素;富集因子法和化学质量平衡法在元素的来源分析上具有很好的一致性。     

济南市开放源细粒子中多环芳烃成分谱研究

目前我国空气污染监测已由无机污染物向有机污染物、粗粒子向细粒子发展,本文通过采样分析获取了济南市八种开放源PM10与PM2.5中多环芳烃的成分谱,为济南市大气颗粒物来源解析以及危害性评价提供基础数据。     

实测数据对大气颗粒物浓度计算模式的验证

针对常用的大气颗粒物(PM10、PM2.5)浓度计算模式计算结果偏差较大的问题,由太原市城区例行监测的PM10浓度估算出燃煤电厂导致的大气颗粒物(PM10、PM2.5)浓度推算值,使用AERMOD和CALPUFF模式计算燃煤电厂排放源导致的大气颗粒物浓度,对大气颗粒物浓度的计算值与实测值进行了比较分析与评估。结果表明:在城市区域,性能较佳的大气颗粒物浓度计算模式是AERMOD模式。     

气溶胶单颗粒分析方法的应用和进展

大气颗粒物污染由于其对区域环境和人体健康的影响而日益成为全球关注的焦点。相对于全颗粒物分析方法,大气单颗粒分析方法可以获得特征单颗粒的形貌、元素组成及粒子数量粒径谱等大量信息,具有采样量少、样品处理过程简单和分析速度快的特点,这使得单颗粒分析已成为表征大气颗粒物理化特征的重要手段。该方法已在源解析、颗粒物基本理化特性、颗粒物的混合状态和老化过程等方面得到应用。本文就单颗粒分析主要方法及其在颗粒物源解析等大气环境化学研究中的应用进行介绍,并对比分析不同单颗粒分析仪器的特点。     

中子活化分析测定大气颗粒物的质量保证

仪器中子活化分析具有灵敏度高、无需样品预处理、可测元素种类多等优点,是大气颗粒物元素含量分析的常用方法之一,为污染源解析提供重要的数据基础。本文归纳整理了NAA实验室利用相对比较法和单比较器k0法分析大气颗粒物样品工作中各实验流程的质量保证过程,以及内、外部质量控制方法。     

北京地区冬季气溶胶分级化学成分及来源分析

在北京城区进行冬季大气气溶胶采样,样品采用PIXE方法进行分析,得到大气气溶胶中20种元素的质量浓度。结果表明:元素Mg、Fe、Si这3种元素均呈粗粒模态单峰型分布,且峰值出现在2～4μm,表明它们来自土壤尘;S、Cl、K等3种元素谱分布呈细粒单峰型分布,峰值都出现在0.25～0.5μm范围内,表明这3种元素主要来自燃煤;Cu、Zn、As、Br、Pb等5种元素谱分布呈双峰型谱分布;Ni、Cu、Zn、As、Se、Br、Pb等元素的粗、细模态的富集因子都较大,尤其是细粒模态,表明这些元素更容易在细粒模态上富集,进一步说明这些元素主要来自人为污染源。因子分析结果表明:土壤尘、煤烟尘、工业源和汽车尾气排放源对北京冬季气溶胶有主要贡献。     

Explosibility boundaries for fly ash/pulverized fuel mixtures

Incomplete combustion and subsequent fuel contamination of a waste stream can pose a serious explosion hazard. An example of this type of incident is the contamination of fly ash with unburned pulverized coal. The coal, if present in sufficient quantities in the mixture, can act as a fuel source for a potential explosion. Experiments were conducted in a 20l Siwek explosibility test chamber to determine the minimum fuel contamination of fly ash required to form an explosible mixture. A sample of fly ash from Ontario Power Generation (OPG) (Ont., Canada) was artificially contaminated with Pittsburgh pulverized coal dust (the surrogate used to represent unburned fuel dust). Additionally, the influence of fly ash particle size on the amount of fuel contaminant required to form an explosible mixture was examined. Fine and coarse size fractions of fly ash were obtained by screening the original sample of OPG fly ash.The results show that at least 21% Pittsburgh pulverized coal (or 10% volatile matter) was required to form an explosible mixture of the original fly ash sample and coal dust. The results also illustrate that fly ash particle size is important when examining the explosibility of the mixture. The fine size fraction of fly ash required a minimum of 25% coal dust (12% volatile matter) in the mixture for explosibility, whereas the coarse fly ash required only 10% coal dust (7% volatile matter). Thus, the larger the particle size of the inert fly ash component in the mixture, the greater the hazard.     

Chinese power-station coal mills use Espey shaft-seals to contain ‘coal dust’

This brief case study looks at a sealing system that is being used in coal mills at a power station in Dezhou, China. The mills produce ‘coal dust’ which is used to fuel steam generators. Designed and developed by German company Gustav Espey GmbH, the seals have proved to be highly reliable and robust, preventing any ‘coal dust’ from being discharged into the atmosphere.     

The effect of foam polystyrene granules on cement composite properties

Crumbled recycled foam polystyrene waste as well as spherical large and fine blown polystyrene waste is used to produce the filler for a light thermo-insulating composite, the matrix of which is light foam cement. For better cohesion, fillers are hydrophilizated with foam cement surfactant solution.Polystyrene granules and foam cement concrete interaction schemes are discussed. The investigation of foam cement concrete and polystyrene granule contact zone showed that the contact of these two materials is very close, without any fractures or microcracks. Adherence of the two components depends on the size and shape of granules used.When a polystyrene granule is ripped out of foam cement concrete, the emerged “hole” closely repeats the structure of the granule and there is some polystyrene residue left in it. This proves the fact that foam cement concrete contact zone is stronger than the polystyrene granule material. When fine polystyrene granules are used, it disintegrates along the contact zone. Such composite has the lowest adhesion strength, however, it is stronger in comparison with a composite, made with different foam polystyrene granules, provided by better macrostructure. Strength and thermal conductivity of the composite depend on its density, the filler, its sort and amount used, and is defined by regression equations.     

Technology assessment for clean energy technologies: The case of the Pacific Northwest

This study presents a technology assessment for clean power generation in the Pacific Northwest. Our goal is to incorporate clean production principles into the evaluation process for power alternatives. Two types of technologies are considered: one is for a renewable energy source (wind) and the other is for a traditional, fossil fuel based energy source (coal). The Analytical Hierarchy Process is used to assess the feasibility of both the wind energy and clean burning coal energy technologies. Criteria such as location, cost, feasibility, and availability are used for evaluations. For the wind energy, cost was determined to be the most important criterion when making a technology decision. For the SO₂ emissions technology, the regenerative process was determined to be the best technology to scrub SO₂ emissions from the air. Additionally, efforts towards renewable energy in Oregon should continue. Both federal and state governments offer tax credits that can help mitigate costs and facilitate the adoption of renewable energy options for power companies.     

中国沙尘暴及其监测预警

利用1954—2001年中国大陆681个站的气象资料，分析了中国沙尘暴的时空分布特征和分级标准，给出了沙尘暴若干观测事实。通过分析沙尘暴的发生发展机制，讨论了沙尘暴的定性预报和定量预报技术，指出发展包含大气运动、风蚀物理过程和下垫面地表信息的集合数值预报模式是沙尘暴定量预警技术的发展方向。同时，指出传统的监测网尚不能全面监测沙尘暴的发生和发展，建立包含下垫面生态环境要素、大气物理化学要素的专业化沙尘监测网络是深化对沙尘暴特性认识和发展沙尘暴定量预警技术的基础。     

Analysis of enzyme dust formation in detergent manufacturing plants

In the detergent industry, enzymes are used to catalyze the breakdown of tough stains such as oils and fats, which cannot be easily removed with surfactants and bleaches. In the 1960s, a number of plant workers developed respiratory allergies from inhaling enzyme dust over long periods. The response from the enzyme manufacturing companies was to encapsulate the enzymes by granulation, fluid bed coating, extrusion and other techniques. The end users of encapsulated enzymes such as the detergent industry concentrated on the installation of engineering containment and dust extraction systems. These were combined with other safe systems of work, including airborne monitoring and health surveillance. The result was a significant decrease in the concentration of airborne enzyme dust in the working environment and virtually eliminated the incidence of respiratory allergy. However, enzyme dust generation has not been eliminated completely and the integrity of the enzyme encapsulates remains a key control point. In 2000, the Enzyme Dust Consortium was formed with the objective to design a validated test method with a protocol (for granule qualification and quality control) to correlate with dust levels in plant. Current test methods for dust formation do not replicate the mechanical stresses in the detergent plant and limit the enzyme manufacturer's ability to develop better granules. Our efforts are focused on evaluating the prevailing mechanical stresses in detergent manufacturing plants and their effect on enzyme granule attrition. Dust sampling of the factory ventilation ductwork show a large variation in enzyme dust levels. This may be attributed to the presence of some weak granules. Nevertheless, the likely sources and mechanisms of enzyme dust need to be identified. Once a new testing procedure is established, enzyme manufacturers will be able to design and produce improved products that will result in a further reduction of enzyme exposure in detergent manufacturing facilities.     

竹材废弃物作为工业锅炉燃料的研究

我国竹材资源在传统制作和工业加工过程中的重量利用率低于40%,有60%以上的竹材成为加工剩余物,竹材生物资源量巨大.竹材的硫和灰分含量仅为洁净煤质燃料的1/5~1/3,是一种非常洁净的燃料.竹材作为工业锅炉燃料时,含水量应控制在20%以下.燃煤锅炉改烧竹材燃料时,需对配风方案、进料机构和局部结构进行改进.竹材废弃物代油燃烧,具有明显的价格优势和环保效益.经济性分析结果表明,在竹材废弃物丰富的地区,开发燃用竹材废弃物的工业锅炉具有良好的经济性.     

北京大气环境的区域特征与沙尘影响

讨论了北京大气环境的区域性特征。利用网络点集确定出大气输送通道，提出了汇聚带概念，同时分析了北京地区大气污染特征，使用激光技术探测了大气气溶胶的垂直分布。研究表明北京大气环境质量与周边地区的污染源有密切的关系，认为只有进行同步治理才能有效地改善首都大气环境的质量。通过卫星监测技术和对气象流场进行分析，对我国沙尘暴现象进行了研究。指出境外沙尘源和境内沙尘源，并以2002年3月20日北京一次特强沙尘暴为例，对原始沙尘源的分布进行了解析，分析指出原始沙尘源包括春季长江以北广大的裸露土地，显示出沙尘暴起始过程是以点源群出现，然后合并为沙尘带，最后出现大面积沙尘污染。并简述了我国现代环境理念。     

A new perspective on the mechanical evaluation of granular material

The mechanical strength of granules is an important parameter to be determined prior to any further downstream formulation processing. It is important to have a good gauge on the granule integrity to forecast any foreseeable powder issues associated with the material processability such as segregation, content uniformity, and material flow-ability. In this study, a systematic methodology has been developed to quantify the integrity of these granules subjected to a low frequency acoustic field to arrive at the Granule Integrity (GI) index. This methodology has been compared to existing well-established bulk characterization techniques reported in the literature such as Heckel analysis, Kawakita analysis, and Young’s modulus for four different processed samples. Heckel analysis is more amenable to examine the material deformability while Kawakita analysis is better suited to understand the mechanics of granular material. Individual granule strength measurements to determine Young’s modulus often show large variations across the bulk sample. The GI index in conjunction with the Kawakita analysis provides us with more mechanistic insight and understanding into the formation of these granules from a processing perspective. This paper shows the benefits of using the GI index as a practical and direct methodology to characterize the GI of bulk samples in an industrial setting.     

燃煤电站利用飞灰脱汞的研究现状

汞的累积性及高毒性使其成为了未来主要的污染物控制对象之一,目前较为成熟的活性炭喷射技术平均汞脱除率能够达到80%-98%,但极高的运行成本仍然难于达到大范围商业推广的要求。飞灰作为燃煤电站的废弃物,成本极低,且同样具备汞捕集能力,某些飞灰的汞脱除能力甚至能够达到商业活性炭级别。本文对目前影响飞灰汞脱除率的研究进行了综述。综合讨论了烟气气氛、煤炭类型、飞灰含碳量、飞灰岩相结构等多种因素对飞灰汞脱除率的影响。明确了飞灰脱汞技术的可行性,以及未来亟待解决的问题。