Identification of Odor Causing Compounds in a Commercial Dairy Farm

The odorous air emissions from confined animal feeding operations (CAFOs), such as swine, poultry and dairy farms, are increasingly raising community complaints. Odorous emissions can result in health damages, psychological discomforts and adverse aesthetic effects in the community. However, these emissions are not well characterized up to now due to the lack of legislation, the limitations in sampling and instrumentation techniques, and the complexity of the emissions themselves. This study is aimed at the development of a high volume sampler and sorbent assembly to identify the odor causing compounds from a diary CAFO. The sorbent was custom designed to target the potential compounds that may exist in a dairy farm and was validated in laboratory with a synthetic odor from the swine manure. The actual samples at the diary farm were collected in spring and summer of 2005. The sorbents were solvent extracted and individual odor compounds were identified using GC–MS (gas chromatography–mass spectroscopy). The data obtained indicated that high volume sampling can shorten the sampling time from days to within 4 h. Both volatile organic compounds (VOCs) and volatile fatty acids (VFAs) have been identified from the dairy farm, such as phenol, methylphenol, 4-ethyl phenol, indole, methyl indole, benzyl alcohol, hexanoic acid, valeric acid and iso-valeric acid, together with some nitrogen containing compounds that have not been reported before.     

碱熔融法合成NaA和NaX型粉煤灰沸石的品质表征

以粉煤灰为原料采用碱熔融法合成了2种单一沸石矿物种的NaA和NaX型沸石,并对产物的结构、性能和应用指标进行了详细表征.经x射线衍射和IR光谱分析,表明合成产物是无杂晶生成的NaA和NaX型沸石相;在扫描电镜观察下,产物分别具有NaA和NaX型沸石的立方体和八面体晶体骨架结构.DTA分析表明了合成产物中沸石水的存在,且产物热稳定性较好.通过对比,粉煤灰合成的NaA和NaX型沸石的比表面积达到了相应商品沸石的66.9%和83.6%;孔容为41.1%和70.2%;阳离子交换容量(CEC,cation exchange capacity)为82.93%和84.31%.通过比较化学组成表明,大规模应用合成产物不会对环境造成危害.     

城市垃圾预处理改善焚烧特性的探讨

针对目前我国城市垃圾的高水分、低热值的特性,提出了2种改善城市垃圾焚烧特性的有效措施:生物质垃圾源分类和生物干燥.在我国建立生物质垃圾源分类体系,将生物质垃圾源头分类后,剩余垃圾的热值可以提高约50%～120%,已适合直接入炉焚烧,同时分离出来的生物质垃圾也更易于好氧堆肥或厌氧消化.另外一项技术措施是在焚烧前利用生物干燥技术,降低城市垃圾的水分含量,提高入炉垃圾的热值,这种方法主要是利用生物反应热来干燥城市生活垃圾,只需要在垃圾投入焚烧炉前增加一个预处理步骤,不必改变目前的垃圾收运体系,而且进行生物干燥后的垃圾更易于分选其中的可回收物质.     

A2/O工艺中的反硝化除磷

A2/O工艺是一种最简单的同步脱氮除磷工艺,但由于其系统中固有的基质竞争和污泥龄等矛盾,在实际应用中特别是处理低C/N比污水时脱氮除磷效率较低.反硝化除磷工艺作为近年来颇受关注的污水生物处理新技术.由于在脱氮除磷过程中可以在碳源利用上耦合,可从一定程度上缓解A2/O工艺中的基质竞争矛盾,使得其在处理低C/N比污水时也能实现较高的脱氮除磷效率.就反硝化除磷的技术原理,结合其在A2/O工艺中的最新研究成果及其控制策略,对A2/O工艺中的反硝化除磷的实现、维持及影响因素进行了分析和探讨,并对其发展方向进行了展望.     

Enhancing community-based disaster preparedness with information technology

A critical component of community-based disaster preparedness (CBDP) is a local resource database of suppliers providing physical, information and human resources for use in disaster response. Maintenance of such a database can become a collaborative responsibility among community-based non-governmental organisations (NGOs) and public and private community organisations. In addition to mobilising resources, this process raises awareness within the community and aids in assessing local knowledge and resources. This paper presents the results of a pilot study on implementing a community-based resource database through collaboration with local American Red Cross chapters and public and private community organisations. The design of the resource database is described. The resource database is accessible via the internet and offline using laptops and handheld Personal Digital Assistants. The study concludes that CBDP is strengthened through a combination of appropriate information technology and collaborative relationships between NGOs and community-based organisations.     

The 2004 Madrid train bombings: an analysis of pre-hospital management

The terrorist train bombings in Madrid, Spain, on 11 March 2004 triggered a swift and massive medical response. This paper analyses the pre-hospital response to the attacks to gain insight into current trends in disaster management among Madrid's Emergency Medical Services (EMSs). To this end, the existing emergency planning framework is described, the basic structures of the different EMSs are presented, and the attacks are briefly depicted before consideration is given to pre-hospital management. Finally, an explanation of the main underlying misconceptions in emergency planning and management in Madrid is provided to aid understanding of the origins of some of the problems detected during the response. These are attributable mainly to inappropriate planning rather than to mistakes in field-level decision-making. By contrast, many of the successes are attributable to individual initiatives by frontline medics who compensated for the lack of clear command by senior managers by making adaptive and flexible decisions.     

海洋巨藻(Durvilaea potatorum)生物吸附剂对Hg~(2 )的吸附动力学研究

对经特殊的稳定化预处理所得的海洋巨藻 (Durvillaeapotatorum)生物吸附剂对Hg2 的吸附动力学进行了研究 ,报导了不同Hg2 初始浓度、温度以及生物吸附剂平均粒径下动态吸附量与时间的关系 .结果显示 ,各吸附动力学曲线呈优惠型 ;当生物吸附剂平均粒径为 0 .45mm时 ,Hg2 的半饱和时间tS均不超过 6 0min ;Hg2 初始浓度和生物吸附剂粒径越小 ,吸附温度越大 ,达到吸附平衡所需的时间越短 .在测试范围内 ,生物吸附剂的平衡吸附容量与粒径和温度无关 .同时考察了吸附过程中的传质效应并对液膜传质系数kL进行了关联 ,结果表明 :当吸附时间t≤tS时 ,Hg2 的吸附速率为液膜传质控制 ;在测试范围内 ,kL为 0 .0 40 7～ 0 .112cm/s.本研究结果为利用海洋巨藻 (Durvillaeapotatorum)生物吸附剂处理含汞废水的规模化应用提供了一定的依据 .图 5表 2参 11     

2,2’,4,4’-和3,3’,4,4’-四氯联苯(TCB)对小白鼠体外受精的影响(英文)

采用体外受精技术评价环境污染物 2 ,2’ ,4,4’ 和 3,3’ ,4,4’ 四氯联苯对小白鼠卵母细胞受精能力和 2 细胞胚胎发育的毒性作用 .实验结果表明 :ρ(PCB) =0 .1,1.0 ,10 .0mg/mL的 2 ,2’ ,4,4’ 和 3,3’ ,4,4’ 四氯联苯均显著降低小白鼠卵母细胞的受精能力 ;ρ(PCB) =1.0 ,10 .0mg/mL的 2 ,2’ ,4,4’ 和 3,3’ ,4,4’ 四氯联苯使卵母细胞的退化率和 2 细胞的畸形率显著增加 ;两种四氯联苯对小白鼠卵母细胞体外受精能力、退化率和 2 细胞胚胎的畸形率无统计差异 .表 2参 2 5     

Identifying the largest individual sample value from a two-way composite sampling design

Composite sampling techniques for identifying the largest individual sample value seem to be cost effective when the composite samples are internally homogeneous. However, since it is not always possible to form homogeneous composite samples, these methods can lead to higher costs than expected. In this paper we propose a two-way composite sampling design as a way to improve on the cost effectiveness of the methods available to identify the largest individual sample value.     

底泥中多环芳烃(PAHs)提取方法评析

总结了底泥中多环芳烃(PAHs)提取的处理流程和国内外多种提取方法,比较了几种在我国较为常用的提取方法的效率.同时还提出了PAHs分离纯化的方法和步骤,并指出了提取过程中影响实验回收率的几个因素.