湿法脱除垃圾焚烧飞灰重金属的研究

以福建和湖北垃圾焚烧发电厂采集的飞灰为研究对象,比较了单独水洗、水洗结合酸洗等工艺对飞灰重金属的洗脱效果,考察了不同酸洗工艺条件下飞灰重金属浸出毒性的变化.结果表明:在水灰比为10时水洗效果最佳,水洗结合酸洗处理可有效降低飞灰重金属浸出毒性,部分飞灰经湿法脱除后可作为普通废物排放.     

城市生活垃圾焚烧飞灰的处理与综合利用

城市生活垃圾焚烧飞灰中可溶性重金属和溶解盐含量较高,并含有二(口恶)(口英)等剧毒有机污染物,一般可认为是危险废物.目前飞灰处置的主要模式是对飞灰进行单独收集,经适当处理后,送入填埋场进行填埋.固化/稳定化和重金属提取是目前飞灰处理的主要方法.介绍了飞灰的4类共9种再利用途径:建筑材料制作(水泥、混凝土、陶瓷、玻璃和玻璃陶瓷),岩土工程应用(道路、筑堤),农业利用(土壤改良剂)和其它(吸附剂、污泥调理剂).     

生活垃圾焚烧厂飞灰无害化处理技术的应用

结合某工程项目案例,阐述采用水泥固化＋螯合剂相结合的处理技术处理飞灰,可以在实现飞灰无害化的同时,达到飞灰少增容,从而提高飞灰处理处置系统的总体效率和经济性。     

适用GB16889—2008的垃圾焚烧厂飞灰处理成本分析

对生活垃圾焚烧厂飞灰采用水泥固化法、熔融固化法和螯合剂稳定化的技术特点进行对比分析,指出目前飞灰处理工艺应采用水泥固化法和螯合剂稳定化的处理方法。简述了GB 16889—2008生活垃圾填埋场污染控制标准有关飞灰的规定,据此对上海江桥生活垃圾焚烧厂飞灰不同处理方法进行财务测算,结果表明:进入生活垃圾填埋场方案的飞灰处理费用将大大低于进入危废填埋场的处置方案,建议采用螯合剂稳定化的方案。     

医疗垃圾焚烧炉飞灰水泥固化体的浸出特性研究

为检验医疗垃圾焚烧飞灰的水泥固化处理效果,对不同养生龄期及不同飞灰／水泥配比下飞灰水泥固化体重金属渗沥特性进行了实验研究。结果表明：随养生龄期的延长,水泥固化体中的Zn、Pb、Cu等重金属渗沥浓度总体上是逐渐降低的;掺40％飞灰、60％飞灰养生28d的水泥固化体中Pb渗沥浓度分别为5．634、6．032mg／L,超过5mg／L的限值。若按照目前国内生活垃圾焚烧飞灰水泥固化工艺的配比（水泥掺量40％以下）,重金属渗沥指标不能达到填埋要求。     

垃圾焚烧飞灰污染特性及其控制对策

分析了上海浦东御桥垃圾焚烧发电厂垃圾焚烧过程的二次污染物——飞灰的污染特性,得出结论：飞灰中Pb和Hg的浸出浓度超过我国危险废物鉴别标准,属于危险废物;飞灰中含有毒有害的二噁英类物质,为0．98—1．50ngTEQ／g;溶解盐含量高达17．4％～21．9％。结合国内外的飞灰管理现状,建议对飞灰先进行适当处理以稳定其中的Pb、Cd、Zn和Hg,达到我国危险废物浸出毒性鉴别标准后,再单独填埋(含渗滤液收集系统、底衬和覆盖层等)。     

垃圾焚烧飞灰固化/稳定化实验研究

探讨了水泥固化和药剂稳定化相结合处理垃圾焚烧飞灰的可行性,结果表明:单独采用普通硅酸盐水泥固化处理垃圾焚烧飞灰,水泥掺量需控制在35%左右;若药剂稳定化与水泥固化联合使用,则药剂添加比为3.0%、水泥掺量为15%时,飞灰固化体即可达到垃圾填埋场入场控制标准。     

生活垃圾焚烧飞灰特性分析

分别对炉排床垃圾焚烧炉飞灰(FA1)和流化床垃圾焚烧炉飞灰(FA2)的化学成分、物相、微观形貌、重金属含量及其渗沥行为等特性进行分析,结果表明:2种飞灰的主要化学成分为SiO2、CaO、Al2O3、Fe2O3等,FA2中高熔点成分含量比FA1高;飞灰的主要物相为SiO2、NaCl、CaSO4等晶体,飞灰颗粒为不规则形;飞灰中Cu、Pb和Zn的含量较多,按照硫酸硝酸法,FA1、FA2中重金属Pb的浸出浓度超过国家规定的危险废物鉴别标准;按醋酸缓冲溶液法,FA1、FA2中的浸出液重金属Pb、Cd浓度都远高于填埋场的限值,需处理后方可进入生活垃圾填埋场填埋。     

垃圾焚烧飞灰中重金属污染物控制的研究进展

介绍了垃圾焚烧过程中重金属污染的来源及其在灰渣中的分布,指出垃圾焚烧后重金属主要集中在飞灰中,飞灰的处理是控制重金属污染的关键。并综述了当前国际上有关垃圾焚烧飞灰中重金属的污染控制方法与技术的研究现状。     

基于XRF检测的飞灰重金属元素数据库构建和分析

使用X射线荧光光谱(XRF)分析仪定量检测生活垃圾焚烧飞灰中重金属总量,并与重金属浸出浓度对比,构建飞灰重金属元素数据库。通过统计分析,可知不同焚烧厂的飞灰重金属含量规律差异较大,飞灰重金属元素的XRF检测值与浸出浓度之间不存在一元线性关系。探讨了飞灰XRF定量检测方法在反映烟气净化辅料用量、预判飞灰样品特性、指导飞灰稳定化药剂添加等方面的应用。     

Calcium intake in the elderly: validation of a dietary questionnaire

Epidemiological studies of calcium and osteoporosis have been hampered by the lack of a suitable tool for assessing calcium intake. This report describes a new frequency and amount questionnaire for measuring present and past calcium intake in the elderly. The validity of the questionnaire was tested against two commonly used standards of dietary assessment, five-day duplicate diets and seven-day weighed dietary inventories. The resulting correlation coefficients were, respectively, r = 0.76 and r = 0.69, while that for repeatability was r = 0.84. Furthermore, the questionnaire categorized subjects into thirds of the distribution of intake with almost no gross misclassification. It is suggested that the present findings may be extended to the majority of normal, healthy elderly subjects, implying wide application for the questionnaire in the assessment of calcium intake in the elderly.     

The human drama of genetics: 'hard' and 'soft' media representations of inherited breast cancer

This paper examines media coverage of 'breast cancer genetics', and explores its implications for public understanding. We present a content analysis of coverage in British newspapers and look at a variety of popular forms, including women's magazines, television soap opera and radio drama. Genetic/inherited risk receives a great deal of coverage across a wide range of media formats and outlets. Much of this attention has focused on individuals from 'high risk families' and dilemmas around prophylactic mastectomies. Through examining media coverage, combined with interviews with media personnel and their sources, we show why this story proved so attractive to the media and highlight the different production values which influence coverage. Finally, we introduce preliminary findings from focus group discussions to demonstrate how such 'human interest' framing has engaged audience attention and influenced public understandings. The paper concludes by highlighting the implications for analysing, predicting, and engaging with, media representations of science.     

Worker education in the primary prevention of occupational dermatoses

This paper reports the evaluation of a skin care education programmeconducted on a fine chemicals manufacturing site where over1,000 employees are located. Approximately 60% are involvedin chemical manufacture. Over a 12 month period production staffreceived training in prevention of occupational dermatoses linkedto a site-wide poster initiative. The incidence of new casesof occupational dermatoses fell from 0.055 (70 cases in 1,277employees) to 0.021 (27 cases in 1,277 employees) before andafter the intervention respectively (p<0.0001). After otherfactors such as chemicals handled, observer bias and changesin reporting related to socioeconomic climate were taken intoaccount it is concluded that this study demonstrates the importanceof worker education as a tool for primary prevention of disease.Training materials such as video and poster presentations maybe effectively used in the chemical manufacturing industry asan adjunct to prevention and control of exposure to substanceshazardous to the skin. Such methods may also be used in otherindustries where there are significant risks of dermatoses.     

Regional Variation in Travel-related Illness acquired in Africa,March 1997–May 2011

To understand geographic variation in travel-related illness acquired in distinct African regions, we used the GeoSentinel Surveillance Network database to analyze records for 16,893 ill travelers returning from Africa over a 14-year period. Travelers to northern Africa most commonly reported gastrointestinal illnesses and dog bites. Febrile illnesses were more common in travelers returning from sub-Saharan countries. Eleven travelers died, 9 of malaria; these deaths occurred mainly among male business travelers to sub-Saharan Africa. The profile of illness varied substantially by region: malaria predominated in travelers returning from Central and Western Africa; schistosomiasis, strongyloidiasis, and dengue from Eastern and Western Africa; and loaisis from Central Africa. There were few reports of vaccine-preventable infections, HIV infection, and tuberculosis. Geographic profiling of illness acquired during travel to Africa guides targeted pretravel advice, expedites diagnosis in ill returning travelers, and may influence destination choices in tourism.     

Self-reported health problems among Swedish miners one year after unemployment

Unemployment is considered to be a public health concern sincedeterioration in the health of the unemployed is often anticipated.However, for some groups, such as miners, unemployment mightimprove health due to a cessation of potentially harmful occupationalexposures. This study evaluates the health of 79 miners in oneSwedish iron-ore mine, and 226 age-matched controls from thegeneral population, during one year after the closure of themine. The participants received a questionnaire regarding medicalhistory and subjective symptoms at the beginning of the studyperiod, and after one year. Statistically significant negativeeffects on self-reported health attributable to unemploymentwere not found, although neuropsychiatric symptoms were morecommon among the unemployed miners. The miners reported a statisticallysignificant improvement in grip force (p=0.031). They had asignificantly higher prevalence of symptoms associated withmining related exposures when compared with the population controls;pain in the upper extremities [relative risk (RR)=2.27, 95%confidence interval (Cl)=1.44–3.59), back pain (RR=1.84;Cl=1.237–2.75), vasospastic disease of the fingers (RR=2.05;Cl=1.18–3.57) and obstructive respiratory symptoms (attacksof dyspnea and wheezing: RR=3.67; Cl=1.167–11.6).     

Excès de cas humains et animaux de tularémie en France au cours de l’hiver 2007–2008 : émergence ou phénomène isolé ?

Context

Tularemia is a zoonosis affecting humans and hares in France. We describe the results of surveillance in both species, in 2007 and 2008.

Methods

Human tularemia cases are mandatorily notifiable in France since 2003. In hares, surveillance relies on volunteer hunter associations in all districts of the country. Data from mandatory reports and volunteer surveillance in 2007/2008 were analyzed and compared with previous results.

Results

In 2007/2008, 144 cases were reported in humans and 117 cases in hares. This was a 100% increase compared to previous years. Human cases differed from those of previous years only by the frequency of contact with breeding animals. Human cases without any documented risk exposure were also more frequent.

Conclusion

An increase of tularemia cases occurred in 2007/2008 in both species. Complementary studies are needed to identify the species reservoir in France to understand the causes of this peak of cases.     

深圳公立医院管理体制改革制度设计

深圳公立医院管理体制改革实行政事分开、管办分开,在理事会架构下按法定机构模式组建市医管中心,落实公立医院运营管理自主权.作者从当前公立医院管理体制的弊端入手,介绍了深圳市进行公立医院管理体制改革的基本思路及改革方案设计的主要举措,深入剖析了的改革方案的特点,并对改革效果进行了预测.     

Effects of nitrogen dioxide on red blood cells of rats: Changes in components of red cell membranes during in vivo exposure to NO2

Red cell membranes, prepared from red blood cells of rats exposed to 4, 10, or 20 ppm nitrogen dioxide (NO₂) for 1 to 10 days, were examined for evidence of changes in membrane components. Appreciable changes were not found in contents of phospholipid and cholesterol during exposure to 10 ppm NO₂. By contrast, protein content altered with the time of exposure. Moreover, changes in protein composition were observed by employing sodium dodecyl sulfate — polyacrylamide gel electrophoresis. Twenty-four-hour exposure to NO₂ at the concentration above 10 ppm resulted in a marked increase in the percentage of lysophosphatidylethanolamine (LysoPE) to the total phospholipids. The prolonged exposure to 10 ppm NO₂ gave rise to a further increase in LysoPE, whereas the percentage of phosphatidylethanolamine (PE) showed a gradual decrease. A 1-day exposure to 4.0 ppm NO₂ also caused an increase in sialic acid content and decreases in those of PE and hexose. In addition to contents of these components the percentage of LysoPE increased 5 days after exposure and the elevated values were maintained up to the end of exposure period. These results demonstrate that red blood cells in circulation exhibit different membrane properties in terms of lipid and carbohydrate composition during 10 days of exposure to 4.0 ppm NO₂.     

The design of hazard risk assessment matrices for ranking occupational health risks and their application in mining and minerals processing

Two hazard risk assessment matrices for the ranking of occupational health risks are described. The qualitative matrix uses qualitative measures of probability and consequence to determine risk assessment codes for hazard-disease combinations. A walk-through survey of an underground metalliferous mine and concentrator is used to demonstrate how the qualitative matrix can be applied to determine priorities for the control of occupational health hazards. The semi-quantitative matrix uses attributable risk as a quantitative measure of probability and uses qualitative measures of consequence. A practical application of this matrix is the determination of occupational health priorities using existing epidemiological studies. Calculated attributable risks from epidemiological studies of hazard-disease combinations in mining and minerals processing are used as examples. These historic response data do not reflect the risks associated with current exposures. A method using current exposure data, known exposure-response relationships and the semi-quantitative matrix is proposed for more accurate and current risk rankings.