化学事故救援方舱舱室环境安全性模拟研究

运用计算流体动力学(CFD)方法,对具有超压防护功能的某化学事故应急救援手术方舱室内气体污染物运动扩散的规律以及对人员安全的影响进行了数值模拟,其研究结果表明:当大气环境中氢氰酸(HCN)浓度为5mg/L时,前10s从常规进风口进入舱室的HCN在滤毒通风装置开启后,随气流运动逐渐向整个舱室扩散,经净化空气的混合稀释作用,绝大部分通过舱体缝隙排出舱室,30min内舱室HCN浓度的总量下降了95.1%,说明超压防护很好地保证了舱室环境的安全性。     

灰色关联分析与内梅罗指数法在克钦湖水体重金属评价中的应用

以扎龙湿地克钦湖水体重金属监测资料为基础,在湖内均匀布设了12个采样点,用电感耦合等离子体质谱仪法测定各点的重金属质量浓度.水体中Mn、Cu、Cd、As、Pb和Se的平均质量浓度分别为2.23 mg/L、0.65 mg/L、0.12 mg/L、5.98 mg/L、0.48 mg/L、0.13 mg/L.应用灰色关联分析方法和内梅罗水污染指数法综合评价克钦湖的水环境质量.结果表明:灰色关联分析方法体现了各评价因子的综合影响,得出克钦湖总体达到V类水质标准,水体受到严重污染;内梅罗指数法反映了各重金属元素的污染程度,由大到小依次为As、Mn、Pb、Se、Cd、Cu.应用两种方法从不同角度分析水体重金属的污染程度,并得出污染原因,最后提出扎龙湿地克钦湖生态环境保护对策.     

焦化废水生物脱氮的试验研究

采用单相活性污泥法对焦化废水进行了试验研究。研究结果表明:当进水NH_3—N浓度为300mg/L左右,COD为1200～1500mg/L,酚浓度为100～380mg/L,CN~-为10～30mg/L,在系统总水力停留时间为27h和混合液回流比为400％的条件下,出水各项污染指标均达到国家排放标准。     

饮用水水源突发性Cr(VI)污染应急处理实验研究

针对水源水突发性Cr(VI)污染进行了应急处理的实验研究.当原水中Cr(VI)质量浓度超过0.100 mg/L时,水厂现行处理工艺不能保证Cr(VI)达标去除.用硫酸亚铁还原法去除水中的Cr(VI),当原水中Cr(VI)质量浓度为0.1～2.0 mg/L,pH值在6.5～8.0时,硫酸亚铁和氯化铁的投量分别控制在3.0～16.0 mg/L和5～15 mg/L,可保证出水总铬质量浓度低于0.02 mg/L,去除率在99%以上,保障了饮用水水质安全.     

以河床井水为应急水源的可行性研究

为解决城市水源地突发污染事故引起的自来水厂断水问题,提出了以河床井水代替受污染河水作为应急水源的应急预案,在取水口附近的河床打一口水井,当城市水源地发生突发污染事故时,关闭取水头水阀,开启水井水阀,以河床井水作为应急水源,并通过模拟试验验证了其可行性.结果表明,在细沙体积分数为40％的土壤条件下,原水苯胺质量浓度分别为952 mg/L、781 mg/L、580 mg/L、452mg/L、352mg/L、182mg/L的试验中,出水苯胺质量浓度开始超标的时间随土壤渗透系数减小而延迟,与原水苯胺质量浓度无关.当土壤渗透系数为1.94×10-5～ 3.64×10-5 cm/s时,出水苯胺质量浓度开始超标的时间为84～ 144h,以河床井水作为应急水源可以避免由河水突发污染引起的84h内的自来水厂断水事故.土壤对苯胺的吸附量仅占原水中苯胺含量的14.95％～ 2.86％,其对出水苯胺质量浓度开始超标的时间的影响可以忽略,出水苯胺开始出现的时间主要由土壤渗透系数决定.出水苯胺最大质量浓度随原水苯胺质量浓度增大呈线性增加,线性方程为y =0.4979x-3.7029,R2=0.9775.研究表明,以河床井水作为应急水源,能够有效地降低城市因突发污染事故而引起的自来水厂断水的可能性.     

硫酸铜和氰戊菊酯对斑马鱼急性毒性试验

为探究重金属和农药对斑马鱼的毒性与安全评价,选用硫酸铜、氰戊菊酯对斑马鱼进行急性毒性试验,以24～96h半致死浓度(LC50)判定斑马鱼对这两种药物的敏感性.结果表明,硫酸铜24 hLC50、48h LC50、72 h LC50、96h LC50分别为12mg/L、7.9 mg/L、6.8mg/L、5.4 mg/L;氰戊菊酯24 h LC50、48h LC50、72h LC50、96h LC50分别为1.2×10-4 mg/L、0.9×10-4 mg/L、0.9×10-4 mg/L、0.9×10-4 mg/L; 硫酸铜安全质量浓度为1.03mg/L,氰戊菊酯为1.52×1O-5 mg/L.参照我国化学物质对鱼类毒性分级标准,判定硫酸铜对斑马鱼急性毒性为Ⅱ级,氰戊菊酯对斑马鱼急性毒性为Ⅰ级.     

铀胁迫对5种牧草种子萌发的影响

为进一步探究放射性重金属铀污染环境对植物种子萌芽及生长所产生的迫害,根据我国铀矿冶废水中铀的质量浓度(5 mg/L)选择不同质量浓度(0、1 mg/L、5 mg/L、10 mg/L、15 mg/L、20 mg/L)的铀溶液进行试验,用以胁迫5种1年生牧草(三叶草、苜蓿草、黑麦草、高丹草和苏丹草)种子,同时观察记录各自的萌发状况(发芽数和第7 d幼苗生长长度),计算其发芽率、发芽势、发芽指数(GI)、活力指数(VI)及耐性指数,并与对照组进行量化指标比较。最后比较各牧草种子所受到的危害并做出评价。结果表明:对于不同程度的铀污染,多数植物表现为低质量浓度促进其种子萌发,高质量浓度则严重抑制甚至致死。对于三叶草、苜蓿草和黑麦草种子,低质量浓度(1 mg/L)铀溶液促进种子的萌发,质量浓度升高则为抑制,其中黑麦草表现稍异常,质量浓度为5 mg/L时对种子萌发有促进作用,使最终发芽率较对照提升14%;对于高丹草,低质量浓度(5 mg/L)时促进种子萌发,而在质量浓度稍低于或超过5 mg/L时表现出明显的抑制现象,各指标低于对照13%左右;苏丹草则仅呈现抑制现象,铀质量浓度为5mg/L时抑制现象稍轻,最终发芽率较对照组仅降4%,小于或大于5mg/L时均受抑制,且质量浓度越高抑制现象越明显,最终发芽率最高仅28%。     

太原市蔬菜中铅、铬和镉含量分析及安全性评价

笔者采用原子吸收光谱法 ,测定了太原市蔬菜批发市场的 8种蔬菜 72个样品的铅、铬、镉含量。结果表明 :在检测的 8种蔬菜中 ,有 5种蔬菜出现铅含量超标 ,铅是蔬菜中的主要污染元素 ,且污染带有普遍性 ;铬的污染仅出现在芹菜和青菜上 ,其他 6种蔬菜均无超标 ;8种蔬菜均未受到镉的污染 ,合格率为 10 0 %。参照国家食品卫生标准和蔬菜质量分级标准 ,对蔬菜的重金属污染程度进行了安全性评价。在所检测的蔬菜样品中 ,只有青菜受到重金属污染 ,其综合污染指数为 1.12 ,污染程度为轻度污染。其他蔬菜的综合污染指数均低于 0 .7,污染程度均为安全 ,污染水平均为清洁。     

航海人员的不安全行为分析与评价模型研究

随着国际、国内对航运系统安全认识的不断提高,航海人员的行为及如何对其安全行为进行科学评价日益受到关注。从人—机—环—管的安全系统基本要素出发,全面分析导致航海人员不安全行为的各种因素。在此基础上提出综合评价航海人员安全行为的指标体系,并探讨以各指标实测值经归一化处理后作为系统的输入,以评价结果作为系统的输出,应用BP神经网络建立综合评价模型。该种评价模型简单、实用,而且克服了其他评价方法中存在的人为和随机干扰,同时也为航海人员的安全行为评价提供了一种新的研究思路。     

商业区与轻轨站厅开口处防火分隔失效时人员安全疏散评估

针对相连接部位开口处的防火分隔失效时人员能否安全疏散进行评估,研讨人员安全疏散评估过程中所采用的定性分析和定量分析方法。以某商场与轻轨站相连接开口处为例,考察当防火分隔耐火性能失效后,商场内人员和轻轨站的人员能否从火灾中得以安全疏散;通过火灾模拟的方法,采用BuildEvac和FDS软件分别对火灾时人员疏散状况和火灾烟气的蔓延情况进行人员疏散模拟和火灾烟气运动模拟。根据模拟计算结果,对商场内人员和轻轨站人员的安全性进行详细分析和讨论,从而得出实例评估结论:当排烟系统正常工作时,即使防火分隔(防火卷帘)失效,火场环境对商业区和轻轨站的人员生命安全在整个疏散过程中均不会构成威胁,所有人员都能安全疏散到安全地点。     

综合管廊天然气舱危险区域划分研究与监控系统设计

随着天然气管道逐渐被纳入综合管廊,天然气舱的安全运营引起广泛关注,但目前针对天然气舱及设备间等场所进行危险区域详细划分,以及事故发生后的现场气体监测设备布置,尚缺少相应的标准和设计规范。因此,从爆炸性气体区域划分、危险气体泄漏量及持续时间、通风效果等方面进行计算和分析,提出天然气舱和设备间的危险区域划分依据;在设备间设置为安全区域的前提下,提出一种本质安全兼隔爆型监控系统的设计思路,进而实现天然气舱内气体的可靠连续监测,为事故发生后的监测提供技术支持。     

Analysis of gas dispersion and ventilation within a comprehensive CAD model of an offshore platform via computational fluid dynamics

Maintaining an adequate air flow with a desired air quality that is free from hazardous gases is among the most important actions taken toward the improvement of safety in any process plant. Due to the increased focus on the consequences of existing hazardous material on safety, health, and the environment, air quality and sufficient ventilation within a plant has been increasingly considered in the design stage. This paper investigates and analyzes methane and hydrogen sulfite dispersion and the effect of air ventilation within a CAD model of an offshore platform using computation fluids dynamics (CFD). In addition, this method and its principals could be utilized in any other hazardous environment. Simulations of possible hazardous events along with solutions for preventing or reducing their probability are presented to better assess the data. These investigations are performed by considering hypothetical hazardous scenarios which consist of gas leakages from pipes and process equipment under different conditions. After drafting a precise and highly detailed CAD model of the plant and performing CFD simulations on this model, the results of gas behaviors, dispersion, distribution, accumulation, and its possible hazards are investigated and analyzed. The larger amount of details of the actual plant model in CFD simulation are obtained by using a combination of different methods and software. These include PDMS for 3-D drawing of the plan, Rinoceros for geometrical integration of the process equipment and facilities, and Sharc Harpoon which meshes the model. Moreover, the probability of inducing ignitable or toxic concentration of gases within the atmosphere and air ventilation of the unit is considered by these investigations.     

A mobile flight case learning system for ATC miscommunications

Aviation’s highest priority is safety. The primary risk to safety derives not from automated systems but from human factors, most notably air traffic control. We present results from development of a flight case learning system designed to operate on mobile phones used by air traffic controllers (ATCs). Our system takes advantage of key Ontology concepts, a case-based system development procedure, human-centered design (HCD) strategies, and appropriate small-screen interface design protocols. A questionnaire to assess user interaction satisfaction (QUIS) was deployed for subsequent usability testing and to verify acceptance of, and satisfaction with, the system. Twelve subjects participated in the questionnaire-based evaluation of subjective satisfaction. In addition, two flight experts served on a review panel for domain knowledge verification and acceptance of the interface design. Our results confirm that the system is a suitably designed mobile learning system that can accelerate self-learning for ATCs.     

呼吸效应对矿井封闭火区氧浓度的影响分析

为避免因火区封闭导致重大安全事故发生,通过采集某矿井1 d内3个不同监测点的大气压力变化情况,建立大气压力波动模型并分析计算,同时建立火区内外压差100,750 Pa情形下的氧浓度模型进而获得火区内侧氧气浓度因呼吸效应,在不同压差、体积大小火区、风阻、瓦斯涌出量、封闭时刻等多因素耦合影响下随时间的变化规律,以评估火区危险性。研究结果表明:井下大气随地面大气周期波动,封闭火区内、外侧之间的气压差因外界大气波动呈现16 h的余弦波动和8 h的线性波动周期变化;密闭质量好的火区具有更好地抗干扰性,内侧氧浓度的降低主要依靠瓦斯稀释;密闭质量差的火区,内侧氧浓度易受到火区涌出瓦斯、外界涌入大气双重影响;火区氧浓度在2%~12%之间波动,以至火区存在发生瓦斯爆炸的可能性;火区内外压差较大时,氧浓度波动变化幅度更大,危险作用持续时间更长。结合火区氧浓度波动模型,可有效地对矿井火区采取安全的防范措施,避免瓦斯爆炸事故发生。     

水泥行业NOx污染防治及减排措施研究

环境污染问题是现代社会面临的一项重要问题。NOx作为大气污染物的重要组成部分之一,我国现行规定水泥行业的NOx排放限值为400mg/Nm^3,这与国际标准之间尚存在较大的差距。近年来,随着社会经济的快速发展,人们对环保的要求也越来越高,因此水泥行业必须要更加开展好NOx污染防治及减排工作。本文主要针对水泥行业NOx污染防治及减排措施进行了研究,希望有助于提升相关工作质量,促进环境保护。     

中心商业区环境安全管理与控制

城市中心商业区环境安全的管理与控制是城市诸多问题中的热点.通过分析中心商业区的环境空气质量和环境噪声、防火防爆设施及应急装备、人流车流秩序、公共卫生系统,提出了在城市中心商业区环境安全的管理与控制中应执行的相关标准,设立了相关部门和管理措施.对中心商业区环境安全控制的规制化具有一定积极意义.     

负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

为掌握负压防护急救车车厢内生物污染物的分布情况,运用计算流体动力学(CFD)方法和拉格朗日颗粒随机轨道模型,对该车车厢内生物污染物的运动扩散进行数值模拟;并通过试验对比研究车厢内污染物浓度场的分布状态,试验与模拟的结果基本一致。同时表明:该随机轨道模型较好地反映生物污染物运动扩散的时空分布特点;负压防护急救车车厢内污染物浓度较高,医护人员应穿戴有效的个人防护器材。     

Railroad injury: Causes, costs, and comparisons with other transport modes

Safety regulators in the railroad industry need comprehensive injury costs by cause, and cost comparisons to other modes of transport to gain policy insights. This study links case-level data from the Federal Railroad Administration to monetary costs and consequences of specific injuries. Lost quality of life was estimated from physicians' ratings of injury impairment and the value of fatal risk reduction. Railroad injuries and illnesses cause an average of $3 billion in fatality costs and $650 million in nonfatal incident costs annually. Impacts at rail-highway crossings impose three times as much cost as the next highest cause. Commercial air travel is the safest per passenger mile. Trains, second lowest, have injury costs six times higher, but only one-fifth as high as cars. The relative safety of trains and airplanes in transport means highway modes enjoy implicit price subsidies. Better injury cost recovery through taxation or insurance would make the subsidies explicit. More informed modal choices and thus enhanced economic efficiency would result.     

Recent development of standardization of testing methods for dust explosion in Japan

The Dust Explosion Committee of the Association of Powder Process Industry and Engineering (APPIE) of Japan has acted to establish the standard for the member of the Association. Two testing methods have been authorized by the Association. The methods are established to evaluate sensitivity and severity for dust explosion.The ignition sensitivity is evaluated by the minimum explosive dust cloud concentration. Tapping sieve equipment and a strictly-specified Hartmann-type explosion tube have been selected as the testing apparatus. The tapping sieve equipment is applied to measure the minimum explosive concentration by forming a dust cloud supplied from a sieve on the top of the explosion chamber. The Hartmann-type tube is used to investigate roughly whether the test powder is explosive or not. A lot of explosion tests had been carried out to standardize the equipment and evaluate the sensitivity. This APPIE standard is being revised.Along with the ISO standard for explosion severity, Research Institute of Industrial Safety, the Ministry of Labour published a Guide to Test Method for Explosion Pressure and Rate of Pressure Rise for Combustible Dusts in 1994. Based on this Guide, The APPIE Committee has made the draft for the member.These standards and drafts are aimed to be the Japanese Industrial Standard (JIS). No other similar standard exists in Japan. In the present paper, technical data and explosion statistics which are the background of the APPIE standard for the ignition sensitivity are to be described.