大气颗粒物采样器的设计与应用

自行开发设计大气颗粒物双通道采样器,通过更换粒径切割器实现对大气总悬浮颗粒物(TSP)、可吸入颗粒物(PM10)或细颗粒物(PM2.5)样品的采集。该仪器通过流量传感器、比例阀和流量控制板精确控制每个通道的采样流量,控制系统还可实时采集大气环境温度、压力、湿度、风速和风向5个气象参数,并根据环境温度、压力的变化对采样的体积流量进行补偿计算,以确保进样口体积流量恒定,保证粒径切割准确。在2011年深圳大学生运动会期间(8月12—23日)和后期(8月24日至9月4日),利用该仪器进行了大气环境野外观测实验,并对该仪器和Thermo2300采样器的结果进行了平行性分析和对比分析,其平行结果和对比结果相关系数均大于0.99。     

Passive monitoring of nitrogen dioxide in urban air: a case study of Durban metropolis, South Africa

To devise and implement strategies to manage the quality of urban air, a metropolis needs air pollution data on which an air quality management plan can be formulated. Although air pollutants can come from several sources, many reports suggest that nitrogen dioxide from motor vehicle emissions is the major contributor to air pollution in cities. Since vehicles stop or move slowly through traffic intersections, concentrations of nitrogen dioxide (NO(2)) are expected to be relatively high at these sites. Inexpensive Ogawa passive samplers were placed at selected traffic intersections in the Durban Metropolis to trap the NO(2) which was then analysed by a sensitive laboratory-based method. The data obtained by this method was compared with data from sophisticated system comprising an active sampler cum on-line chemiluminescence detector. The sampling was done over a twelve month period to cover all seasons. Statistical analysis of the data showed that there was no significant difference between the means for the two methods. This study has established that an Ogawa passive sampler may be used as an economical and reliable collector for NO(2) in ambient air under varying climatic conditions. Further, the analysis method using a UV-Visible spectrophotometer was sensitive enough to detect NO(2) at the 10-20 ppb level. The cost of the method should be well within the budgets of most municipalities and it would motivate them to develop policies to alleviate traffic congestion.     

Air-soil exchange of organochlorine pesticides in a sealed chamber

So far little is known about air-soil exchange under any sealed circumstances (e.g., in plastic and glass sheds), which however has huge implications for the soil-air-plant pathways of persistent organic pollutants including organochlorine pesticides (OCPs). A newly designed passive air sampler was tested in a sealed chamber for measuring the vertical concentration profiles of gaseous phase OCPs (hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs)). Air was sampled at 5, 15, and 30 cm above ground level every 10th day during a 60-day period by deploying polyurethane foam cylinders housed in acrylonitrile butadiene styrene-covered cartridges. Concentrations and compositions of OCPs along the vertical sections indicated a clear relationship with proximity to the mixture of HCHs and DDTs which escapes from the soils. In addition, significant positive correlations were found between air temperatures and concentrations of HCHs and DDTs. These results indicated revolatilization and re-deposition being at or close to dynamic pseudo-equilibrium with the overlying air. The sampler used for addressing air-soil exchange of persistent organic pollutants in any sealed conditions is discussed.     

重庆市春季大气NO2浓度空间分布特征研究

为了解重庆市大气中NO2浓度空间分布特征，研究了一种被动式采样器在该地区野外采集大气NO2的可行性，并在2004年3～5月期间利用这种采样器对重庆城区2600Km^2范围大气中的NO2进行了连续观测。结果表明：NO2浓度值随城区类型、观测点位置不同有一定的差异，其分布与交通强度密切相关；前后两次观测有相同(除南岸区外)的区间浓度梯度。     

不同材质采样器采样对降水离子组分的影响研究

采用了四种材质即聚乙烯、聚氯乙烯、硬质玻璃和金属加特氟龙涂层采样器，在同一地点、同一时间采集同一场降雨，所获得的样品经过中速定量滤纸过滤，在相同实验条件下进行离子色谱分析。结果表明：聚氯乙烯材质采样器采集的降水样品pH值降低，电导率升高，且使其中的氯离子浓度产生显著性差异，其余材质采样器所采集的降水样品中的各阴离子浓度无显著性差异；四种材质采样器所采样的降水样品中的各阳离子浓度也无显著性差异。     

携带式大气采样器存在问题探讨

通过实践总结出携带式大气采样器存在的问题，并对其改进方法做了详细的研究。     

EFFECTS OF SPATIAL ORIENTATION OF MULTIPLE PLATE ARTIFICIAL SUBSTRATES ON INVERTEBRATE COLONIZATION1

ABSTRACT: Jumbo multiple plate samplers were suspended in a river at 0.3 and 1 m depth in one of three orientations: interplate spaces closed to downwelling light and open to flow, open to light and flow, or open to light and closed to flow. Mean numbers of colonizing taxa and individuals were not significantly different among orientations after eight weeks of submergence. All variables tested decreased significantly with depth. Mean number of taxa, number of individuals (1 m only), and insect diversity decreased between samplings at four and eight weeks for samplers that were closed to light and open to flow. All orientations, depths, and durations had one-half to two-thirds of the total taxa. Colonization was affected by location in the river and position on sampler suspension equipment. The results indicate lack of orientation effects on colonization or high variability that obscured such effects. The sampler suspension equipment possibly increased among-sampler variability by forming artificial snag habitats, and interplate light and flow conditions at different orientations may not have been sufficiently distinct to elicit different biological responses. Individual samplers provided diverse microhabitats regardless of orientation, but it would be prudent to include orientation among the variables considered in use of multiple plate samplers.     

Andersen酸雨采样器与国产酸雨采样器监测数据对比分析

对美国Andersen酸雨采样器与国产酸雨采样器在pH、电导率、雨量三方面的采样性能作了比较试验，结果表明监测数据基本一致，其中pH值的可比性最好，相关系数达到0.99;Andersen酸雨采样器采集的样品其电导率普遍低于国产酸雨采样器，说明该仪器在防颗粒物干扰方面性能较好。     

多孔喷嘴PM10-PM2.5串级冲击式大气采样器的研制及应用

多孔喷嘴冲击式大气采样器广泛应用于大气环境监测,相对于单孔喷嘴采样器,它具有压差小、相同空气雷诺数下采样流量大等特点.利用Marple的冲击理论,设计了一种中流量PM10-PM2.5串级冲击式大气采样器,采样流量为100L/min.用该采样器进行实地测量,通过PM2.5/PM10的比值分析,该采样器测量的PM2.5/PM10数据基本与文献报道一致.     

Atmospheric PAH concentrations in fine and coarse particles

Measurements of the urban air concentrations of PAHsassociated with PM2.5-fine and PM10-coarse particles inChicago on the campus of IIT were achieved using a UniversalAir Sampler. Short sampling time (12 hr) and high flowrates were used to measure the PAH concentrations in fineand coarse particles. Measured ambient concentrations ofPAHs were classified based on wind direction and backtrajectory calculations as Land and Lake samples.Differences in ambient concentrations of PAHs were observedbetween Land and Lake samples. Fine particle concentrationsvaried from 9.5 to 25.7 ng m^-3 and averaged18.2 ng m^-3 for the Land samples, while they ranged from4.2 to 31.5 ng m^-3 and averaged 13.4 ng m^-3 for the Lake samples. The measured PAH concentrationsin coarse particles varied from 6.2 to 22.1 ng m^-3 and averaged 12.9 ng m^-3 for the Land samples, andthey ranged from 2.4 to 13.0 ng m^-3 with an average value of 7.3 ng m^-3 for the Lake samples. The fine/coarse ratio of each individual PAH compound varied between1.3 and 2.7 for the Land samples; it varied between 1.6 and 4.2 for the Lake samples. There was an increase in the fine/coarse ratio of PAH as molecular weight of the compound increases for both Land and Lake samples.