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61.
利用生物模拟被动采样研究第二松花江吉林市段的有毒有机污染物种类,并与鱼的生物富集及沉积物的吸附作用进行了比较。对采样器,鱼类及沉积物样品中难降解有机物的分析可以看出、难降解有机污染物在三者之间的分布有较好的对应关系。生物模拟被动采样技术一定程度上模拟了具有生物有效性的难降解有机污染物的富集过程。  相似文献   
62.
Goal, Scope and Background Some anthropogenic pollutants posses the capacity to disrupt endogenous control of developmental and reproductive processes in aquatic biota by activating estrogen receptors. Many anthropogenic estrogen receptor agonists (ERAs) are hydrophobic and will therefore readily partition into the abiotic organic carbon phases present in natural waters. This partitioning process effectively reduces the proportion of ERAs readily available for bioconcentration by aquatic biota. Results from some studies have suggested that for many aquatic species, bioconcentration of the freely-dissolved fraction may be the principal route of uptake for hydrophobic pollutants with logarithm n-octanol/water partition coefficient (log Kow) values less than approximately 6.0, which includes the majority of known anthropogenic ERAs. The detection and identification of freely-dissolved readily bioconcentratable ERAs is therefore an important aspect of exposure and risk assessment. However, most studies use conventional techniques to sample total ERA concentrations and in doing so frequently fail to account for bioconcentration of the freely-dissolved fraction. The aim of the current study was to couple the biomimetic sampling properties of semipermeable membrane devices (SPMDs) to a bioassay-directed chemical analysis (BDCA) scheme for the detection and identification of readily bioconcentratable ERAs in surface waters. Methods SPMDs were constructed and deployed at a number of sites in Germany and the UK. Following the dialytic recovery of target compounds and size exclusion chromatographic clean-up, SPMD samples were fractionated using a reverse-phase HPLC method calibrated to provide an estimation of target analyte log Kow. A portion of each HPLC fraction was then subjected to the yeast estrogen screen (YES) to determine estrogenic potential. Results were plotted in the form of 'estrograms' which displayed profiles of estrogenic potential as a function of HPLC retention time (i.e. hydrophobicity) for each of the samples. Where significant activity was elicited in the YES, the remaining portion of the respective active fraction was subjected to GC-MS analysis in an attempt to identify the ERAs present. Results and Discussion Estrograms from each of the field samples showed that readily bioconcentratable ERAs were present at each of the sampling sites. Estimated log Kow values for the various active fractions ranged from 1.92 to 8.63. For some samples, estrogenic potential was associated with a relatively narrow range of log Kow values whilst in others estrogenic potential was more widely distributed across the respective estrograms. ERAs identified in active fractions included some benzophenones, various nonylphenol isomers, benzyl butyl phthalate, dehydroabietic acid, sitosterol, 3-(4-methylbenzylidine)camphor (4-MBC) and 6-acetyl-1,1,2,4,4,7-hexamethyltetralin (AHTN). Other tentatively identified compounds which may have contributed to the observed YES activity included various polycyclic aromatic hydrocarbons (PAHs) and their alkylated derivatives, methylated benzylphenols, various alkylphenols and dialkylphenols. However, potential ERAs present in some active fractions remain unidentified. Conclusions and Outlook Our results show that SPMD-YES-based BDCA can be used to detect and identify readily bioconcentratable ERAs in surface waters. As such, this biomimetic approach can be employed as an alternative to conventional methodologies to provide investigators with a more environmentally relevant insight into the distribution and identity of ERAs in surface waters. The use of alternative bioassays also has the potential to expand SPMD-based BDCA to include a wide range of toxicological endpoints. Improvements to the analytical methodology used to identify ERAs or other target compounds in active fractions in the current study could greatly enhance the applicability of the methodology to risk assessment and monitoring programmes.  相似文献   
63.
报警器使用过程中经常出现准确度下降、零点漂移、检测器损坏等问题,严重影响着企业的安全生产.分析了可燃气体报警器使用过程中存在的问题,提出了相应的解决方案.  相似文献   
64.
半渗透膜采样技术在有机污染物监测中的作用   总被引:6,自引:1,他引:6       下载免费PDF全文
介绍了半透膜装置的组成和特点、半渗透膜采样技术的优点及其在有机污染物监测中的应用,指出该技术可用于研究有机污染物在空气、生物、水体中的分布和迁移规律,以及与有机污染物相关的生态毒理实验。  相似文献   
65.
电石法制氯乙烯生产装置涉及到乙炔、氯化氢、氯乙烯等众多的易燃、易爆、有毒物质,反应条件苛刻,系统一旦失控,极易发生火灾、爆炸、中毒等重大事故。因此,对氯乙烯生产装置进行危险性分析具有重要的意义。本文采用危险性和可操作性研究及故障类型影响分析方法分别对氯乙烯生产装置工艺过程及设备的危险性进行了分析,找出了可能引发系统失控的工艺偏离及原因,并提出了控制措施。  相似文献   
66.
Objective: Powered mobility devices (PMDs) are commonly used as aids for older people and people with disabilities, subgroups of vulnarable road users (VRUs) who are rarely noted in traffic safety contexts. However, the problem of accidents involving PMD drivers has been reported in many countries where these vehicles have become increasingly popular.

The aim of this study is to extract and analyze national PMD-related accident and injury data reported to the Swedish Traffic Accident Data Acquisition (STRADA) database. The results will provide valuable insight into the risks and obstacles that PMD drivers are exposed to in the traffic environment and may contribute to improving the mobility of this group in the long term.

Methods: The current study is based on data from 743 accidents and 998 persons. An analysis was performed on a subset of data (N?=?301) in order to investigate the development of accidents over a period of 10 years. Thereafter, each accident in the whole data set was registered as either single (N?=?427) or collision (N?=?315).

Results: The results show that there was a 3-fold increase in the number of PMD-related accidents reported to STRADA during the period 2007–2016.

With regard to single accidents, collisions, as well as fatalities, the injury statistics were dominated by males. Single accidents were more common than collisions (N?=?427 and N?=?316, respectively) and the level of injury sustained in each type of accident is on par.

The vast majority of single accidents resulted in the PMD driver impacting the ground (87%), due to either PMD turnover (71%) or the driver falling out of the PMD (16%). The reason for many of the single accidents was a difference in ground level (34%, typically a curb).

Cars, trucks, or buses were involved in 67% of collision events; these occured predominantly at junctions or intersections (70%).

Abbreviated Injury Scale (AIS) 3+ injuries were dominated by hip and head injuries in both single accidents and collision events.

Conclusions: The present study shows that further research on PMD accidents is required, with regard to both single accidents and collision events. To ensure that appropriate decisions are made, future work should follow up on injury trends and further improve the quality of PDM-related accident data. Improved vehicle stability and design, increased usage of safety equipment, proper training programs, effective maintenance services, and development of a supporting infrastructure would contribute to increased safety for PMD drivers.  相似文献   
67.
弹上火工品报废处理技术研究   总被引:1,自引:1,他引:0       下载免费PDF全文
齐伟 《装备环境工程》2020,17(11):132-136
针对导弹弹上待报废火工品如何进行销毁处理问题,通过对待报废火工品性能特点进行全面分析,按照火工品销毁处理的原则,研究针对弹上待报废火工品的处理方法,同时对处理方法进行技术特点分析及实施方案介绍。提出对弹上火工品销毁按照分类采用分解销毁、爆炸销毁和燃烧销毁三种方法,介绍了三种销毁方法的技术特点和实施方案,同时较详细地研究了火工品销毁的技术安全要求。根据弹上火工品性能差异特点和火工品销毁处理安全性要求,对弹上待报废火工品可采用分解、引爆和燃烧的销毁方法,为有关部门进行火工品报废处理提供理论支持与技术参考。  相似文献   
68.
采用Ontario Hydro方法对某100MW燃煤机组进行了烟气汞取样测试,获得了选择性催化还原(SCR)脱硝装置、静电除尘器(ESP)和湿法烟气脱硫装置(WFGD)对烟气汞形态转化和脱除特性规律.借助程序升温脱附(TPD)、扫描电子显微镜分析(SEM)和X射线荧光光谱分析(XRF)等方法探究了飞灰对汞的吸附特性及吸附后汞的热稳定性.结果表明,在75% MCR和85% MCR不同的机组负荷下,SCR+ESP+WFGD对烟气总汞(HgT)的联合脱除率分别为92.83%、81.66%.SCR对元素汞(Hg0)的氧化率与燃煤氯(Cl)含量正相关,Cl含量为500mg/kg时,氧化率高达96.18%.ESP在完全脱除颗粒汞(HgP)的同时对Hg0和氧化态汞(Hg2+)的平均脱除率分别为12.73%和27.79%,ESP飞灰中的未燃尽炭和金属氧化物(Al2O3、Fe2O3)是吸附气态汞的关键组分,汞在飞灰表面主要以HgCl2、HgS(红色)和HgO的形态存在,高于190℃时会分解再释放.WFGD对Hg2+的平均脱除率为91.10%,并能将部分Hg2+还原成Hg0,存在明显的汞二次释放问题.  相似文献   
69.
研究了某典型焦化工业场地建筑物和生产设施表面Pb的污染特征及其存在的健康风险.在该场地选择了56个建筑物和生产设施,采用美国环保局(United States Environmental Protection Agency,US EPA)的擦拭取样方法,采集了94个擦拭样品,分析了建筑物和生产设施表面Pb的含量,目的是...  相似文献   
70.
呼吸器是一种自给式的呼吸保护器具,被广泛运用到消防、化工、船舶、石油、矿山等行业,其主要分为空气呼吸器、氧气呼吸器、氮氧混合呼吸器和潜水呼吸器。一直以来,作为特种设备的呼吸器用气瓶阀并没有相关的国家标准,而GB 15382-2011《气瓶阀通用技术条件》并不包括呼吸器用气瓶阀,因此有必要制定相关的国家标准来对其进行规范。目前,《空气呼吸器用气瓶阀技术条件》国家标准已经出台征求意见稿,本文针对意见稿的相关内容,对阀门进出气口连接型式、过滤装置、限流要求、泄压装置及爆破压力等方面提出相关意见和建议。  相似文献   
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