Aspects of Tests and Assessment of Filtering Materials Used for Respiratory Protection Against Bioaerosols. Part I: Type of Active Substance,Contact Time,Microorganism Species

This paper presents the results of a study on antimicrobial activity of polymer filter nonwovens produced by needle-punching or melt-blowing with an addition of disinfecting agents. The first part of the paper discusses how the biocidal activity of nonwovens is a function of the active agent added to the nonwovens, the duration of the contact of microorganisms with nonwovens and the type of microorganisms. The types of fibres and disinfecting agents had a considerable effect on the biocidal activity of nonwovens. The biocidal effect of nonwovens increased with the duration of their contact with microorganisms. Fibre activity differed considerably depending on the species of the microorganism. The microorganisms most sensitive to biocidal activity of the active filter nonwoven were S. aureus, M. flavus and E. coli. There were no biocidal effects on spore-forming bacterium B. subtilis.     

Investigation of Blended Fibre Filtering Materials

Five variants of mixtures of different synthetic fibres at different area ratios were manufactured into needled nonwovens intended to be used as a filtering material for respiratory protection. Two variants were produced according to an earlier patent, and the contents of the other three was completely new. Samples of the nonwovens were tested for sodium chloride particles penetration and for breathing resistance. The results showed that one variant of a nonwoven, designated PP/PPFM, had very valuable filtering properties and that those properties were stable in time.     

Strategies and methods for investigation of airborne biological agents from work environments in Germany.

In 2004/2005, a European Twinning Project was carried out to support Polish occupational safety and health institutions in putting into practice Directive 2000/54/EC regarding the protection of workers from risks related to exposure to biological agents at work. Information on and training in sampling and analysing biological agents of people responsible for bioaerosol measurements and the assessment of measuring results from the workplace atmosphere were part of the project. This paper is an extract of the authors' activities within the project and can be used as a tool for comparable activities in future projects with other European Union candidates. It gives information on working standards for bioaerosol measurements worked out and commonly used in Germany within the frame of European guidelines for bioaerosol measurements in the workplace atmosphere. Additionally it summarizes the authors' long practical experience in carrying out bioaerosol measurements in the atmosphere of various workplaces.     

Filtration Properties of Nonwovens

Abstract

This paper presents the results and conclusions from experimental investigations concerning filtration properties of nonwovens. The needled nonwovens were made from polyester fibres (PTE) with average fibre diameter 12 µm and polypropylene fibres (PP) with average fibre diameter 32 μm. Nonwovens were produced out of each of those fibres or out of a mixture of polyester and polypropylene fibres. This paper also presents investigations of nonwoven fabric made of polypropylene fibres (PP) with average fibre diameter 2.6 μm, which was formed according to melt-blown technology. Oil mist, as challenge aerosol, was used to evaluate the performance of filter media at various aerosol velocities. The average oil mist test aerosol particle diameter was 0.3 μm. Filter penetration was measured at oil mist concentration 0.24 g/m³.     

不同环境温度和活动强度下人体出汗率测定

提出了一种测定人体出汗量的方法—衣物增重法,并利用该法分别测定20、25、28℃环境温度下,8名受试者在跑步机上分别以2、4、6mi/h(54、107、161 m/min)的速度跑步15min后的出汗量。运用配对样本t检验,并对出汗率测定结果进行分析后发现,环境温度和活动强度对人体单位面积出汗率均有显著影响,环境温度分别为20、25、28℃以及活动强度分别为2、4、6mi/h时,人体单位面积出汗率的范围为1.605～681.100 g/(h.m2)。     

一种抗菌生物防护口罩的研制

具有抗菌功能的生物防护口罩对于预防呼吸道传染病的流行、保护人员健康具有重要的意义。本文采用化学键结合的方法将生物抗菌剂ε-聚赖氨酸(ε-PL)固定在聚对苯二甲酸乙二酯(PET)非织造布上并与其它过滤材料复合,采用密合拱型结构设计研制出一种具有抗菌功能的生物防护口罩。实验结果表明,该口罩对菌悬液和微生物气溶胶的抗菌率分别为99.99%和81.9%,且抗菌性能稳定;对颗粒气溶胶和微生物气溶胶的过滤效率分别为99.32%和99.99%,在满足GB19083的基础上具有优良的生物防护性能。     

固定剂对土壤中Cr形态变化及生物可利用性的影响

为了考察固定剂对土壤中重金属Cr形态变化及生物可利用性的影响,用天然沸石、FeSO4、MgO质量比为2∶1∶1的物质组合作为固定剂,取一定量风干后的Cr污染棕壤土样,按照5%的比例加入固定剂。在封闭的体系里培养1周后,用Tessier序列提取法提取土壤中添加固定剂前后不同污染程度时各形态的Cr,并对生物可利用性进行评价。结果表明,Cr在土壤中的存在形态以残渣态比例最高,固定剂的添加使Cr向稳定的铁锰结合态和有机结合态方向转变,降低了碳酸盐结合态的比例,从而使Cr的生物利用性和迁移性降低,减小了Cr进入生物链的几率,一定程度保证了土壤使用的安全性。     

汽车用聚合物材料火灾燃烧特性研究

为研究车用聚合物材料的燃烧特性，并对材料的火灾危险性进行全方位的评估，采用锥形量热仪，对汽车上常用的ABS，PP-PVC，PVC革-无纺毡以及无纺布-PVC聚合物材料进行分析表征，测得点燃时间、热释放速率、总热释放量、质量损失速率、烟气生成速率等参数。结果表明:ABS材料的点燃危险性相对最低，PVC革-无纺毡材料相对最高；随热辐射强度的增加，各样品的热释放速率和烟气生成速率明显加快；结合热释放速率峰值、均值和总热释放量可知，无纺布-PVC材料的热危险性相对最低；结合烟气生成速率和总烟释放量可知，ABS材料的发烟危害性相对最高，无纺布-PVC的相对最低；综合比较各样品的FGI和FPI值，安全等级由高到低依次为ABS，PP-PVC，PVC革-无纺毡，无纺布-PVC。     

Efficiency of Filtering Materials Used in Respiratory Protective Devices Against Nanoparticles

The basic aim of this research was to establish the efficiency of filtering materials widely used in respiratory protection devices with particular interest in their porosity, degree of electric and changeable process parameters, such as the flow rate of the test nanoaerosol and the size range of nanoparticles. Tests were carried out with an NaCl solid aerosol of 3.2 × 10⁵ particles/cm³ for the range of particle size of 7–270 nm, at aerosol flow rate of 1800, 2700, 3600, 4500 and 5400 L/h. The tests showed that electrospun nonwovens were the most effective filtering materials for nanoparticles over 20 nm. Melt-blown electret nonwovens with lower porosity than electrospun nonwovens had higher values of penetration of 1%–4%. Those materials provided very efficient protection against nanoparticles of certain sizes only.     

Study of Fe–Co mixed metal oxide nanoparticles in the catalytic low-temperature CO oxidation

Iron–cobalt mixed metal oxide nanoparticles (Co/Fe molar ratio: 1/5) have been prepared by a simple co-precipitation method and employed as catalyst in low-temperature CO oxidation. The prepared catalysts were characterized by thermal gravimetric and differential thermal gravimetric analyses (TGA/DTG), X-ray diffraction (XRD), temperature programmed reduction (TPR), N₂ adsorption (BET) and transmission electron microscopy (TEM) techniques. The results revealed that inexpensive iron–cobalt mixed metal oxide nanoparticles have a high potential as catalyst in low temperature CO oxidation. The results showed that increasing in calcination temperature increased the crystallite and particle size and decreased the specific surface area, which caused a decrease in catalytic activity of prepared catalysts. In addition, the pretreatment conditions affect the catalytic activity and catalyst pretreated under oxidative atmosphere showed the higher activity than those pretreated under reductive and inert atmospheres.     

城市污水处理厂职业健康风险评估研究进展

为进一步开展城市污水处理厂职业健康风险评估工作,运用文献调研方法对国内外城市污水处理厂职业健康风险评估研究现状进行综述和展望。研究结果表明:目前,污水处理厂职业健康风险评估主要针对有毒有害气体和生物气溶胶2类危害因素;主要采用问卷调查、矩阵法和剂量-反应模型等3种评估方法;噪声和人机工程等职业危害因素的健康风险评估、暴露特征污染物的识别、复合污染物的健康风险评估、职业与非职业危害因素对工人健康影响等研究工作还有待开展。     

Modelling ice and wax formation in a pipeline in the Arctic environment

In the Arctic environment, the fluid temperature in the pipeline can drop below the freezing point of water, which causes wax and ice to form on the pipeline surface. Solid formation on the pipeline surface can lead to flow assurance and process safety issues, such as blockage of the pipeline, pipeline component failure, and release of hazardous liquid. Remediating the plugging requires a shutdown of pipeline operation, which incurs tremendous cost and delays the entire production system. In order to prevent blockage, the pigging operation can be used to remove the deposits on the pipeline surface on a regular interval. Ice and wax depositions in the pipeline are a slow process. However, if the deposition grows too thick, pipeline blockage can still occur after pigging operation. So, ice and wax deposition rates are required to be estimated accurately. This paper investigates ice and wax deposition rates in a 90,000 m pipeline. A fundamental model for both ice and wax deposition is proposed using the first principles of heat and mass transfer.     

污水处理厂微生物气溶胶的暴露风险评价

为了给污水处理厂微生物气溶胶的健康风险评价提供定量依据,于2011年6—7月利用Andersen 6级撞击式空气微生物采样仪对西安市第三污水处理厂氧化沟单元内不同距离处的细菌气溶胶进行现场采样,利用平皿培养和菌落计数对细菌进行分析。选用适于我国国情的暴露因子参数,建立暴露风险评价模型,对污水处理厂的工人及周围居民的健康风险进行评价。评价点的细菌气溶胶浓度采用修正的高斯模型计算。结果表明,呼吸吸入是人体(儿童和成人)摄入微生物气溶胶的主要途径,暴露非致癌风险商随距离的增加而逐渐降低。同种途径在同样位置,儿童的风险商是成年男性或成年女性的2~3倍。经呼吸途径的风险商从大到小为儿童、成年男性、成年女性,经皮肤接触途径的风险商从大到小为儿童、成年女性、成年男性。     

养殖池塘生态系统中磷的收支及解磷微生物的研究进展

综述了池塘养殖系统磷的收支情况.研究发现,在池塘养殖系统中,磷输出最主要的形式为底泥沉积,养殖池塘中存在着磷的总体利用效率不高,水体中活性磷含量低的问题.而解磷微生物的应用在一定程度上可有效解决上述问题,它们能将植物难以吸收利用的磷转化为可吸收利用的形态.通过阐述解磷微生物的种类、解磷效果及解磷机制,结合养殖池塘的情况,分析了将解磷微生物应用于水产养殖中的可行性,并对今后的研究方向作出了展望.结合我国水产养殖的实际情况,筛选适应池塘养殖环境的高效解磷微生物,并将其应用于池塘养殖中,使池塘沉积物中难溶性磷转化具备相当的可行性.     

超压防护急救车车厢内生物污染物运动扩散的数值模拟与试验验证

为考核超压防护急救车通过生物污染区域时的车厢环境安全性,运用CFD方法和拉格朗日颗粒随机轨道模型,对车厢内的生物污染物运动扩散进行了数值模拟,并通过试验对比研究了车厢内污染物浓度场的分布状态.试验结果与模拟结果基本一致,说明拉格朗日颗粒随机轨道模型能较好地反映生物污染物运动扩散的时空分布特点,超压防护急救车车厢环境安全性良好.     

全身正压生物防护服防护性能研究

为研究动力送风全身式正压生物防护服对人员的防护性能,采用标准方法检测正压生物防护服气密性和液体喷溅防护性能,连续监测穿着正压生物防护服活动时的内部正压值变化。采用微环境气溶胶密闭舱室平台,研究正压生物防护服对黏质沙雷氏菌(ATCC 8039)和phi-x174噬菌体气溶胶的整体防护性能。结果表明,正压生物防护服气密性和液体喷溅防护性能均达到气密型防护服和喷射液密防护服水平。对2种生物气溶胶的防护效率均在99.97%以上,且与送风量与环境湿度无关。正压生物防护服被人员穿着进行作业时,其内部能始终能保持大于16 Pa的正压。对该防护服防护性能的系统分析能全面评估类似防护服的整体防护性能,也为未来各类正压式防护服研发和防护性能研究提供技术参考。     

饮用水生物稳定性控制指标体系研究

主要阐述了饮用水生物稳定性的主要控制指标AOC(可生物同化有机碳)、BDOC(可生物降解溶解性有机碳)、TP(总磷)、MAP(可生物利用磷)、BGP(细菌生长潜力)及其测定方法和AOC-T DWMS评价体系.利用层次分析法确定了在城市输水管网中各控制指标的重要性权,使城市饮用水的处理更具有针对性,保证城市饮用水的生物稳定性.     

免疫磁珠分离技术在环境病原微生物检测中的应用

介绍免疫磁珠分离技术的原理和操作步骤,分析其主要影响因素.介绍该技术在环境样品病原菌、原虫及病毒检测中的应用及研究进展.环境样品成分复杂,需经适当分离纯化处理再进行病原微生物检测,从而保证检测结果的可信性.免疫磁珠分离技术兼具免疫反应的特异性及磁性分离的快速性,能够有效分离纯化环境水样中的病原微生物,广泛应用于病原微生物的检测.     

水环境中轮状病毒分子生物学检测技术

轮状病毒是重要的水介传播病原体,其感染性强,稳定性高,是水环境中危害严重的病原微生物,快速、准确地检测水环境中的轮状病毒对于控制疾病爆发和保障水质公共卫生安全极为重要.本文系统介绍了水环境中病毒浓集方法、核酸提取方法以及分子生物学检测方法,综述了水中轮状病毒浓集和分子生物学检测方法的研究进展,并探讨了分子生物学方法在检测水环境中轮状病毒存在的问题及发展趋势.     

水平弯管内硫沉积数值模拟研究

元素硫在集输管道中沉积会引起堵塞和腐蚀问题,而弯管是集输管道中较易出现硫沉积的部位之一。为此,采用数值模拟的方法研究水平弯管内的硫沉积问题,首先利用雷诺应力模型对流场进行模拟,其次采用Lagrange颗粒轨道模型对硫颗粒进行模拟追踪,研究不同因素对硫颗粒在弯管中沉积率的影响。结果表明:弯管内壁会出现负压区和低速区,气流速度和弯曲比会对流场产生影响;硫颗粒在弯管中的沉积率随流速、粒径和弯曲比的增大而增大;硫颗粒沉积是重力和离心力共同作用的结果,其中离心力是导致弯管中沉积率增大的重要原因。