城市污泥反应器堆肥实验

采用强制通风好氧静态方式对城市污泥进行堆肥实验,结果表明:通过调节城市污泥水分和C/N,经过好氧反应器堆肥处理,污泥有机质发生降解,TN、TP和TK含量都呈上升趋势,VS和有机碳分别达到60%和30%的稳定状态,种子发芽指数达到100%左右,有效杀灭病原菌,实现城市污泥无害化、稳定化和减量化的要求.腐熟的污泥堆肥成为高价值的农用产品.     

污水处理厂污泥好氧发酵堆肥农用研究进展

介绍了污泥好氧发酵堆肥技术工艺流程,探讨了好氧发酵堆肥工艺的影响因素,并分析该工艺技术的环境效益、社会效益和经济效益。     

城市污泥中甾类在堆肥、消化过程中的稳定性

在应用气相色谱-质谱仪联机检测技术（GC/MS）对深圳、广州两地城市污泥中甾类污染物进行检测的基础上,研究污泥堆肥、消化过程中甾类的转化、降解稳定性。研究结果表明,深圳和广州两地城市污泥中含有丰富的甾类污染物,主要来源于家庭生活污水,且以动物来源甾类为主,植物和酵母细菌来源次之。好氧堆肥对广州污泥和厌氧消化对深圳污泥中大部分甾族化合物均有明显的降解作用。好氧堆肥并不能促进甾醇中稳定组分甾酮的转化,厌氧消化亦不能使甾酮丰度降低。这表明有环境微生物介入的转化、降解作用与化合物本身的化学稳定性并不一定吻合。     

有机固体废物处理行业臭气的产生与控制

针对目前主流的有机固体废物处理处置工艺,总结了各工艺的臭气成分和影响因素。恶臭物质NH3和H2S在污泥堆肥、污泥干化、餐厨垃圾好氧分解和生活垃圾填埋场中都有产生,但不同处理工艺的主要致臭物质不同。污泥堆肥工艺的主要致臭物质为含硫化合物,污泥干化工艺和垃圾填埋场的主要致臭物质为苯系物和萜烯类,餐厨垃圾好氧分解的主要致臭物质为含氧类化合物。提出了相应的恶臭防控措施。     

用排水管污泥混合堆肥或做建筑材料的可行性研究

对利用城市排水管污泥进行堆肥和做建材进行探讨，通过采用高温好氧混合静态堆肥进行实验，可知排水管污泥经堆肥处理后，可达到我国的无害化处理要求。将排水管污泥与粘土混合烧制成砖和陶粒。测试表明用排水管污泥烧制砖或陶粒具有可行性。     

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。     

模糊数学法在堆肥腐熟度评价中的应用

根据常见物料的自身特征及国内外评价堆肥腐熟度的相关标准,提出以堆肥高温期持续时间、C／N降解速率、NH3-N／NO3-N、种子发芽指数、NH3-N降解速率5个指标作为堆肥腐熟度的判别指标,并基于模糊数学方法建立腐熟程度的综合判别模型,然后利用该模型验证了分别以污水污泥和生活垃圾为物料的3种堆肥样品的腐熟度。结果表明,利用这5个指标,通过综合判别模型可以作为污泥（C／N初≥C／N终）、生活垃圾高温好氧堆肥腐熟程度通用的判别方法．判别结果合理且较符合实际。     

污泥好氧堆肥不同阶段通风量研究

讨论了通风控制对污泥好氧堆肥堆体温度变化的影响,分析了堆体温度变化曲线与合理通风量之间的关系。并根据不同学者的研究结果,提出污泥好氧堆肥合理通风量及控制方式,指出在污泥好氧堆肥堆体起爆阶段采用微量0．01m3／（m3．min）通风,缓慢升温阶段通风量为0．02m3／（m3．min）,快速升温期通风量为0．04m3／（m3．min）,高温维持期通风量为n17m3／（m3·min）,降温期通风量为0．04m3／（m3·min）。通风控制采用温度反馈一时间联合控制方式,通风间隔为20min。     

造纸污泥交替好氧厌氧堆肥中氮素的形态转变研究

通过交替式好氧厌氧堆肥处理造纸污泥试验,研究氮素的变化规律.结果表明:堆肥初始的中高温期,主要是堆体中的有机氮转化为氨氮;之后的降温期和腐熟期是硝态氮形成的主要阶段;总氮在整个堆肥阶段呈上升趋势.无机氮(NH3-N,NO-3-N)可以直接被作物吸收,是污泥堆肥中的主要氮素形态,因此减少堆肥初期氨氮的挥发,增加腐熟阶段NO-3-N的形成,以及降低滤液中无机氮的流失是提高造纸污泥堆肥肥效的关键.     

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,...     

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.     

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.     

Assessing occupational and environmental exposure

Exposure assessment is a poorly understood component of the science of epidemiology. The relationship between exposure to chemicals and ill-health outcomes is often calculated using crude exposure measures such as ever/never exposed or duration. When investigating subtle effects, exposures need to be characterized much more fully in terms of intensity, frequency, duration and route. While occupational exposures tend to be much greater than those experienced from the wider environment there is a need to remember that, for many chemicals, exposure can occur occupationally, environmentally and through consumer use of products containing the material of interest. Inhalation exposure has generally been the traditional focus for most epidemiological investigations but there is now growing awareness of the importance of the dermal and ingested routes of contact and internalization. Quantification of the exposure also needs to be related to a biological mechanism of action and exposure metrics need to be selected accordingly. Occupational exposures can generally be measured using simple well-validated techniques. Environmental exposures require much more sensitive instruments and are more difficult to assess. Exposure modelling, particularly for the environmental fate of chemicals has undergone many recent developments and Monte Carlo techniques can be used to characterize model uncertainty and variability. This approach to exposure assessment can now be used in the setting of the wider environment and will enable a far better understanding of the relationship between exposure and disease.     

Mercury toxicity due to the smelting of placer gold recovered by mercury amalgam

A 19-year-old man developed tremor in both hands and fatigue after starting work at a placer gold mine where he was exposed to mercury-gold amalgam. Examination revealed an intention tremor, dysdiadochokinesis and mild rigidity. The 24-h urinary mercury concentration reached a peak of 715 nmol/l (143 ug/l) shortly before the clinical examination, after which he was removed from working in the gold room [Mercury No. Adverse Effect Level: 250 nmol/l (50 ug/l)]. On review 7 weeks later his tremor had almost resolved and the dysdiadochokinesis and rigidity had gone. The 24-h urinary mercury concentration had fallen to 160 nmol/l (32 ug/l). The principal exposure to mercury was considered to be the smelting of retorted gold with previously unrecognized residual mercury in it. The peak air concentration of mercury vapour during gold smelting was 0.533 mg/m3 (Mercury Vapour ACGIH TLV: 0.05 mg/m3 TWA). Several engineering and procedural controls were instituted. This episode occurred at another mine site, unrelated to Mount Isa Mines Limited.     

How Adults with Acquired Brain Damage Perceive Computer Training as a Rehabilitation Tool: A Focus-group Study

The aim of this study was to explore and describe how adult outpatients with acquired brain damage and referred to occupational therapy perceive computer training with the RehaCom programs, in order to evaluate the method of treatment as a tool in the rehabilitation of persons with cognitive disorders. By using focus-group discussions as a qualitative method of research when analysing the result, five themes with corresponding categories emerged, describing a development of understanding and learning about capacities. Themes describing how the participants could apply strategies to overcome shortcomings in daily occupations and the therapeutic role of the occupational therapist were identified as well. The result shows that a computer training program such as RehaCom can be used as an educational tool, for example, to guide a person who is trying to adopt compensatory strategies to avoid overload by taking pauses. It was found that anything the participants learned was also applicable to occupational performance in daily life.