沈阳市生活垃圾好氧堆肥实验研究

以城市生活垃圾为堆肥原料,庭院垃圾和秸秆为填充料,进行了2组堆肥实验,在堆肥周期内定期测定了含水率、有机质含量、灰分含量、堆体质量和堆体温度等参数,并根据所得实验数据对堆肥的影响因素进行了分析。     

强制通风堆肥技术处理农村生活垃圾的可行性研究

对北京市海淀区北部新区农村生活垃圾中的有机成分进行3组不同物料配比的堆肥试验,在堆肥周期内对堆体的理化性质、腐熟度指标与控制参数进行了研究.结果表明:农村生活垃圾中的有机成分含水率偏高,不利于直接堆肥.采用强制通风静态好氧堆肥,堆肥过程中温度、含水率、体积、pH、电导率、碳氮比的变化与一般堆肥过程各参数的变化规律相似,...     

调理剂对城市粪便垃圾堆肥的影响

采用静态仓考察添加不同调理剂的粪便和垃圾混合堆肥过程的物理化学性质.结果表明:相对于锯末、干树叶和稻壳,玉米秸秆可以调节生活垃圾与粪便混合堆料孔隙率和堆料结构强度,是最合适的调理剂.主发酵期堆肥含水率降低较多,腐熟期变化较小.孔隙大的堆料结构和高温有利于含水率下降.堆肥初期有酸化现象,添加2%石灰调节pH可以避免严重酸...     

餐厨垃圾高效好氧堆肥小试装置及机理研究

将粒径为30 mm的餐厨垃圾与锯末混合均匀,调节含水率至50%后进行小规模好氧堆肥试验,通过测定堆料的温度、pH、水溶性C/N和总有机碳下降率推断反应进程.结果表明:堆肥反应装置可以使堆肥顺利升温.最高温度达到60.5℃,并且高温期(＞55℃)持续6 d,所得堆肥产品的理化性质和卫生指标符合国家相关标准.通过通入40℃恒温水提高堆肥的环境温度,可加快堆温的提升,提高堆肥效率和热灭活效果.     

生活垃圾与植物废弃物混合堆肥过程重金属的形态变化

中试规模条件下,以有机生活垃圾与植物废弃物为原料,考察堆肥过程重金属形态变化。结果表明:重金属Pb、Cd和Zn由其它形态向Fe-Mn结合态转化,堆肥结束时,Fe-Mn结合态分别占各自总量的56.0%、48.7%和64.1%;残渣态的Ni向有机结合态和Fe-Mn结合态转化,堆肥结束时,Ni主要以残渣态和有机结合态存在;Cu和Cr主要以残渣态存在,分别占各自总量的64.9%和77.5%。堆肥会使重金属Pb、Ni、Cu和Zn的生物有效性略微增加,而Cr的生物有效性则出现了下降。源分类收集垃圾堆肥样中各种重金属含量均低于混合收集垃圾堆肥样,说明采用源分类方式收集生活垃圾进行堆肥处理,可有效控制堆肥产品中的重金属含量。     

初始物料含水率对餐厨垃圾高温好氧消化过程的影响

利用自制好氧消化反应装置对3组不同初始含水率的物料进行了小规模模拟试验,通过测定物料中水溶性凯氏氮、水溶性总有机碳和水溶性碳氮比、pH来推断反应进行的程度。结果表明:在堆料初始环境温度为50℃,水溶性C/N约18∶1,通风量为16.69m3/d的初始条件下,综合水溶性TOC的降解率和实际生产过程的要求,物料配比m餐厨垃圾/m锯木粉=3∶1(即含水率约为55%)时为最佳值,水溶性TOC可由4.97%降至1.84%。同时最佳值下,物料水溶性C/N最终可降至7.19,接近腐熟程度;在本实验通风和加热条件下,不同含水率的物料最终含水率均可降至25%左右。     

《环境卫生工程》2006年总目次

期页沈阳市源分类有机生活垃圾堆肥研究冯磊Bernhard Raninger李润东李延吉姚伟1(1)河北省城市生活垃圾处理现状及产业化分析马建立郭斌周保华周江亚1(4)填埋场封场绿化工程设计与应用(7)王辉黄建东郑尧1填埋场封场绿化工程设计与应用(7)王辉黄建东郑尧1新加坡对固体废弃物管理的实践和面临的挑战(9)施惠生施慧聪1污泥衍生活性炭技术研究(14)宋薇聂永丰金宜英1公厕规划的理论和方法探讨———以广州市公厕规划为例尧文元江斯潘志坤钟观福沈阳市电子废物产生量估算及管理对策金志英梁文隋儒楠建筑垃圾填埋场的环境效应袁玉玉王罗春赵由才城…     

通风量和翻堆对生活垃圾好氧生物干化的影响

以高含水率混合收集生活垃圾为对象,试验研究了通风量和翻堆对其生物干化效果的影响.结果表明:通风量与物料温度及有机物降解率呈反比;水分去除量同时受物料温度及通风量影响,产物含水率最低的适宜通风量为0.064m3/(h·kg);翻堆能进一步改善干化效果,在适宜通风量条件下,每2 d翻堆1次,产物含水率为53.7%,水分去除率达0.472 kg/kg.     

静态好氧堆肥处理城市生活垃圾的工艺特性

生活垃圾堆肥装置——好氧静态立式发酵仓具有温度控制、通风自动控制系统。用该装置对城市生活垃圾进行了堆肥试验，对堆肥过程的温度、pH值、含水率、耗氧量和有机质等参数进行监测，表明堆肥过程能顺利进行，堆肥产品的卫生指标符合国家标准；堆肥过程中含水率和有机质VS含量明显减少；通过对堆肥的通风加热，能加快温度提升，加快堆肥过程。     

水洗-脱水预处理降低餐厨垃圾堆肥含盐量的实验研究

利用水洗方式对餐厨垃圾进行预处理,考虑了加水量、搅拌时间、温度时除盐率和水洗废水水质的影响;同时对后续离心脱水最佳工艺条件进行实验.结果表明:除盐最佳工艺条件为温度25℃,搅拌时间10 min,m(水)/m(餐厨垃圾)=2,餐厨垃圾堆肥舍盐率可由(1.38±0.02)%降至(0.57±0.05)%;离心脱水最佳工艺条件为脱水时间6 min,离心速度4 000 r/min,餐厨垃圾含水率由95.10%降至72.86%.     

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 occurrence of antimicrobial substances in toilet,sink and shower drainpipes of clinical units: A neglected source of antibiotic residues

Antibiotics represent one of the most important drug groups used in the management of bacterial infections in humans and animals. Due to the increasing problem of antibiotic resistance, assurance of the antibacterial effectiveness of these substances has moved into the focus of public health. The reduction in antibiotic residues in wastewater and the environment may play a decisive role in the development of increasing rates of antibiotic resistance. The present study examines the wastewater of 31 patient rooms of various German clinics for possible residues of antibiotics, as well as the wastewater of five private households as a reference.To the best of our knowledge, this study shows for the first time that in hospitals with high antibiotic consumption rates, residues of these drugs can be regularly detected in toilets, sink siphons and shower drains at concentrations ranging from 0.02?μg·L^?1 to a maximum of 79?mg·L^?1. After complete flushing of the wastewater siphons, antibiotics are no longer detectable, but after temporal stagnation, the concentration of the active substances in the water phases of respective siphons increases again, suggesting that antibiotics persist through the washing process in biofilms. This study demonstrates that clinical wastewater systems offer further possibilities for the optimization of antibiotic resistance surveillance.     

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.     

Occupational health hazards in mining: an overview

This review article outlines the physical, chemical, biological, ergonomic and psychosocial occupational health hazards of mining and associated metallurgical processes. Mining remains an important industrial sector in many parts of the world and although substantial progress has been made in the control of occupational health hazards, there remains room for further risk reduction. This applies particularly to traumatic injury hazards, ergonomic hazards and noise. Vigilance is also required to ensure exposures to coal dust and crystalline silica remain effectively controlled.     

Manufacture and use of nanomaterials: current status in the UK and global trends

This paper provides an overview of the production and use of nanomaterials (NMs), particularly in the UK. Currently, relatively few companies in the UK are identifiable as NM manufacturers, the main emphasis being the bulk markets in metals and metal oxides, and some niche markets such as carbon nanotubes and quantum dots. NM manufacturing in the UK does not reflect the global emphasis on fullerenes, nanotubes and fibres. Some assumptions have been made about the types of NM that are likely to be imported into the UK, which currently include fullerenes, modified fullerenes and other carbon-based NMs including nanotubes. Many university departments, spin-offs and private companies have developed processes for the manufacture of NMs but may only be producing small quantities for research and development (R&D) purposes. However, some have the potential to scale up to produce large quantities. The nanotechnology industry in the UK has strong R&D backup from universities and related institutions. This review has covered R&D trends at such institutions, and appropriate information has been added to a searchable database. While several companies are including NMs in their products, only a few (e.g. manufacturers of paints, coatings, cosmetics, catalysts, polymer composites) are using nanoparticles (NPs) in any significant quantities. However, this situation is likely to change rapidly. There is a need to collect more information about exposure to NPs in both manufacturing and user scenarios. As the market grows, and as manufacturers switch from the micro- to the nanoscale, the potential for exposure will increase. More research is required to quantify any risks to workers and consumers.     

Investigating clusters in the workplace and beyond

Clusters of disease are common and occur in the workplace and in the general community. They often arouse considerable concern among the population. Investigations have sometimes lead to exciting new knowledge, but in general the investigation of clusters is difficult and often unrewarding, especially for community clusters. In the workplace, investigations are more likely to find associations and even new causes, but still many clusters remain enigmatic. Despite this, there are many reasons for investigating clusters, including allaying community concern and identifying uncontrolled exposures. A structure for investigating clusters in the workplace is suggested.