空气中总挥发性有机物检测吸附率影响因素分析

采用正交实验分析了Tenax TA为吸附管、复合吸附管采样各因素对总挥发性有机物中易穿透组分正己烷、苯吸附率的影响及优化,采用复合吸附管采样,于温度25～45℃、组分浓度0.03～1.80 mg/m3的条件下,可使正己烷及苯等的吸附率达到99%以上,为检测方法准确度的提高奠定了基础。     

T-C复合吸附管对空气中苯系物检测准确度的研究

以T-C复合吸附管采样检测室内空气中苯系物,在温度25～40℃、相对湿度10%～90%的采样条件,可使苯系物的吸附率达到98.4%～99.8%,方法精密度达到1.4%～4.8%,回收率达到103.4%～112.4%,准确度很高。     

Tenax-TA吸附解析空气中的研究

利用Tenax—TA和活性炭以不同流速吸附苯,并解析。通过回收率、穿透率的比较,认为在一定的流速以内,Tenax-TA吸附解析空气中苯的数值是可以参考的。     

关于《民用建筑工程室内环境污染控制规范》中苯和TVOC标准曲线绘制和适用性问题的讨论

从活性炭和Tenax—TA的吸附效率、二硫化碳的提取效率、Tenax-TA的热解吸效率等方面,对苯和TVOC标准曲线的绘制和适用性问题进行验证,并对影响标准曲线准确性和应用性的一些试验条件提出了改进建议。     

活性炭吸附检测空气中苯方法的溶剂影响及解决方法

通过实验分析苯检测过程中,使用液体外标法配置标准吸附管时,溶剂的种类和浓度对标准曲线的影响,提出并论证有效的解决方法.     

室内空气中TVOC检测方法的探索与研究

根据《民用建筑工程室内环境污染控制规范》,对室内空气中总挥发性有机物(TVOC)的气相色谱进行了分析,研究了吸附管、载气、气相色谱仪等对TVOC测定结果的影响,并在检测过程中进行对比、总结,以提高检测技术和手段。     

Tenax-TA吸附管和热解吸技术在集体防护系统检测设备校准技术中的应用

本文从对常用的化学毒剂侦检技术进行介绍,并详细介绍了Tenax吸附管和热解吸技术的优势所在以及在校准技术中的研究应用情况,提出了我国防化装备技术的发展要求,可为集体防护系统建设发展提供科学参考。     

兰州市绿色建筑室内空气中苯和TVOC污染研究

为了解兰州市绿色建筑室内空气中苯和TVOC污染程度,通过对兰州市碧桂园二期一星级绿色居住建筑长期检测,确定绿色建筑室内空气苯和TVOC浓度水平及影响因素。试验结果表明:同一房间不同功能区室内空气苯浓度表现为卧室客厅厨房,TVOC浓度表现为卧室厨房客厅;随着高度的增加,室内空气苯和TVOC浓度逐渐降低;新风系统的运行可有效降低室内空气苯和TVOC污染;室内装饰装修会显著增加室内空气苯和TVOC污染;兰州市绿色建筑室内空气苯和TVOC污染相对较轻。     

上海市建筑室内空气污染现状研究

选取上海地区82间办公室和48户住宅,以《室内空气质量标准》为检测和评价依据,以室内空气中的甲醛、TVOC和苯作为代表污染物,对其浓度水平进行了分析.从中发现目前民用建筑室内空气质量超标情况普遍,除客厅污染物超标率偏低外,厨房和书房中甲醛的超标率较高,书房中TVOC的超标率最高,卧室中苯的超标率最高.同时根据目前检测指标的选取情况发现大多数居民对于室内空气污染整体认识还需加强.     

吸附剂Tenax—TA和活性炭对空气中苯的吸附性能比较

分别采用吸附剂为Tenax-TA和活性炭的吸附管模拟现场采集室内环境空气,了解Tenax-TA和活性炭对空气中苯的吸附性能。当Tenax-TA吸附剂以0.5L/min的流量采集10L空气时,苯存在漏出现象。说明空气中苯的采集不宜用Tenax-TA吸附剂替代活性炭吸附剂。     

Tenax-TA吸附剂检测室内空气中苯浓度的影响因素分析

通过测定苯回收率的方法探讨了使用Tenax-TA吸附剂检测室内空气中苯浓度的影响因素,如样品浓度、Tenax-TA试剂重量、采样温度、采样流速、采样体积等.试验结果表明,在一定浓度范围内,样品浓度不影响苯回收率;采样流速对苯回收率影响较小;而Tenax-TA试剂重量、采样温度和采样体积对苯回收率影响显著.     

Comparison Of Tenax And Carbotrap For VOC Sampling In Indoor Air

The most important features of Tenax and Carbotrap, solid sorbents used widely for sampling organic pollutants in air, have been tested under the conditions requested for surveys in indoor spaces and for determinations of VOC emitted from indoor sources by chamber experiments. The performances of samplers, tested with 10 nonpolar and polar (mostly lipophilic) hydrocarbons, present as vapours in 0.5 to 2.0 litre air samples, include: (a) accuracy and reproducibility of the measured concentration, (b) background or “blank” of samplers, (c) stability upon storage (at ambient and below ambient temperatures) of clean samplers and of samplers loaded with VOC, and (d) performance stability after several sampling desorption cycles. The results fulfil the requirements for both adsorbents, though each presents some different drawbacks. In particular (a) Tenax samplers show a “blank” (90 percentile) of 16 ng of benzene and 5 ng of toluene, Carbotrap samplers roughly twice as much; (b) the samplers may be stored for one month either before or after use and (c) they may withstand many cycles without discernible deterioration.     

Vegetal fiber paper matrix impregnated with silica gel for benzene removal

Removing benzene from indoor space plays an important role in indoor air purification. A novel filter with vegetal fiber paper (VFP) as matrix hosting silica gel is proposed in this paper for benzene removal. In order to investigate the feasibility and performance of this idea, firstly, three pieces of VFP samples impregnated with different amounts of silica gel are fabricated and their benzene adsorption quantities are tested. The results show that three times is recommended as the optimal number for impregnating. The VFP sample impregnated with silica gel after the third impregnating exhibits commendable coating stability and good benzene adsorption performance. Additionally, at low relative pressure (P_b/P_s ≤ 0.05), the experimental data of benzene adsorption isotherms fit well with the Langmuir model with R² greater than 0.97. Then, two actual filters made of VFP impregnated with silica gel after the third impregnating were fabricated. It is found that the pressure drop of the actual filter is only 1200 Pa/m when the air velocity is 2 m/s. Besides, the one‐pass efficiency of the filter can reach to 19.44%. It is expected that the silica gel coated on the filter can be modified to improve the purification performance of the filter.     

The application of heat pipe heat exchangers to improve the air quality and reduce the energy consumption of the air conditioning system in a hospital ward—A full year model simulation

Research was conducted to study the effect of heat pipe heat exchangers on the existing air conditioning system of a hospital ward located in Malaysia, a tropical region. The present research employs the transient system simulation software (TRNSYS) to study the hour-by-hour performance of the system in terms of supply duct air and indoor air conditions in the ward space. Fieldwork study showed that the existing air conditioning system operating in the Orthopaedic Ward, University of Malaya, Malaysia is not capable of providing the desired supply duct air and indoor air to the space. Therefore, the possibility of improving the air conditioning system by adding heat pipe heat exchangers was investigated. The impact on energy consumption, power savings, supply duct air and indoor air with heat pipe heat exchangers incorporated in the air conditioning system were simulated and the results were compared with the existing system.Based on the present research, the system with the added eight-row heat pipe heat exchangers is recommended to provide convenient and healthy air into the ward space according to the ASHRAE recommendations. Moreover, it was found that by applying the new design, a considerable amount of energy and power could be saved.     

用子高密度显热机房排热的分离式热管换热器性能优化分析

分析了应用于信息机房空调系统的热管换热器的流程.热管换热器的总驱动温差为室内外温差,单级热管换热器内部制冷剂的恒温特性导致室内换热器和室外换热器两侧热容不匹配、等效热阻较大,可通过增加热管级数来降低换热器的热容不匹配程度,从而降低等效热阻,提高换热效率.     

Monitoring of indoor volatile organic compounds and polycyclic aromatic hydrocarbons arising from kerosene cooking fuel.

Air samples, representing indoor environments of a kitchen in which a kerosene stove was used were collected and analysed for volatile organic compounds (VOCs) viz., n-hexane, benzene, heptane, toluene, p- and o-xylene and n-decane using a cryogenic preconcentration system and a gas chromatograph with a flame-ionisation detector. Simultaneous outdoor samples were also collected to determine indoor to outdoor (I/O) ratios for each compound. Reversed phase high performance liquid chromatography (HPLC) with ultra violet absorption detection was optimised for separation and quantification of polycyclic aromatic hydrocarbons (PAHs) in air particulate matter. Concentration of total suspended particulate matter (TSPM), benzene soluble organics and the PAHs in air samples collected in indoor environment of some tenements at Trombay, Mumbai where kerosene is used as cooking fuel are discussed in relation to the concentration of the same in outdoor environment in vicinity of the tenement. VOCs and PAHs results from samples collected in kitchens in Trombay are discussed in relation to indoor air pollution.     

Ambient air measurements of aromatic and halogenated hydrocarbons at urban,rural and motorway locations

Concern over the carcinogenic properties of certain volatile organics in air, particularly benzene, has recently been expressed. Reductions in the lead content of perol in the United Kingdom and other European countries are predicted to change the concentrations of aromatic and halogenated hydrocarbons (1,2-dichloroethane and 1,2-dibromoethane) in ambient air. In order to provide baseline air quality data, prior to progressive reductions in the lead content of petrol, this study reports the results of a monitoring survey of ambient air concentrations of aromatic and halogenated hydrocarbon concentrations at urban, rural and motorway locations. A thermal desorption/gas chromatographic method analysing Tenax GC sampling tubes was utilised. Highest concentrations for benzene (9.7 ppb) and toluene (15.5 ppb) were measured at the urban site. The average benzene concentration is comparable with a proposed ambient air quality standard in the Federal Republic of Germany. Multiple regression analysis of nonmethane hydrocarbon and carbon monoxide air quality data demonstrated the importance of meteorological variables in defining measured concentrations. The toluene/benzene ratio (w/w) provided useful information in determining the degree of vehicle-related air pollution and supported evidence obtained from dynamometer studies of dealkylation of higher aromatics to benzene in engines operating at high speed and load at the motorway site.     

Volatile organic compounds in indoor environments in Mumbai, India

Air samples, representing different types of indoor environments, were collected and analyzed for eight hydrocarbons namely, n-hexane, benzene, heptane, toluene, p- and o-xylene, ethyl benzene and n-decane using a cryogenic preconcentration system and a gas chromatograph with a flame-ionization detector. Simultaneous outdoor samples were also collected to determine indoor to outdoor (I/O) ratios for every compound at each location. In all, seven different types of indoor environments were investigated for VOC levels. Toluene concentration levels were found to be high in a hall which was recently renovated. The indoor environment of a kitchen in which a kerosene stove was used and smoker's rooms showed high levels of benzene. The concentrations of VOCs during painting were found to be high and the levels of VOCs depended on the type of paint used. The study revealed that the indoor concentrations of selected VOCs on occasions could be significantly high due to various sources. The data presented here can be useful in developing air quality standards for indoor air.     

用Tenax-TA吸附剂检测空气中的苯及TVOC的方法研究

通过改变Tenax-TA吸附剂的量、采样的温度、样品的采集体积等条件,研究这些条件的改变对Tenax-TA对苯及TVOC的吸附性能的影响。实验表明,用Tenax-TA吸附剂在合适的条件下能同时准确定量空气中的苯及TVOC。