降水中 SO_2含量与大气中 SO_2表面浓度的相关性

作为美国多洲电力生产大气污染研究(简称MAP3S)的一部分,作者从1978年10月以来对大气中SO_2浓度进行了连续监测。同时,用Battelle和Aero-chem两种不同的采样器采集降水样品分析。为确定雨水中所含SO_2和大气中SO_2浓度的相关程度,以及所溶SO_2对降水酸度的贡献,作者对两种采样器所提供的数据、温度、SO_2的数据等进行了分析。研究结果扼要如下: (1)用Battelle采样器所采集的雨样中S_1v的含量接近于相对应的大气SO_2表面浓度的平衡值。Aerochem采样器所采样品结果偏低。作者认为降雨中气—液相间的平衡建立的相当迅速。若样品收集、保存得当,平衡值可维持不变。 (2)冬度时S_1v对总游离酸度的贡献高达13％,而在夏季则降到零。 (3)雨水中SO_4~(2-)的含量与大气中 SO_2表面浓度呈负相关。     

KCY—L型空气总氚采样器

上海市工业卫生研究所研制的以氧化——冷凝程序组装的KCY-1型空气总氚采样器,已于1983年12月由上海市环境保护局和上海第一医学院联合组织鉴定、一致通过。该采样器的基本原理是根据氧化-冷凝程序来采集空气中的总氚样品。利用催化燃烧室把水状态的氚全部氧化成同一的水蒸汽状态,然后用冷凝程序加以捕集。采样器由四部份组成:第一部份是催化燃烧室,它的功能是把样品空气中的非水形     

不同级数的ANDERSEN生物粒子采样器采样效果的比较

用不同级数的FA-I型、FA-Ⅱ型和由FA-I型6级简化为2级型的3种类型的ANDERSEN生物粒子采样器，在室内外对空气微生物粒子浓度、粒子大小分布的采样效果进行了比较，同时对FA-Ⅱ型生物粒子采样器的性能进行了检测。结果表明，5台FA-I型生物粒子采样器的第1级、第2级采集的空气微生物粒子数和所占粒数百分比均无明显差别；逃失率为3．3％。FA-I型和FA-I型采样器对空气微生物粒子浓度的采样效果也没有明显差别；由FA-I型6级简化为2级型的采样器与FA-I型采样器对空气微生物粒子浓度和粒子大小分布的采样效果有明显差别，FA-I型采样器不宜简化为2级型采样器使用。     

上海大气中花粉与颗粒物的复合污染特征

于2009~2010年,利用风标式花粉采集器,采集了上海不同区域春、秋、冬季的飞散花粉和大气颗粒物样品,并于春季(2010年4月)利用重力花粉采集器在不同高度采集了飞散花粉样品,以及不同区域悬铃木的花粉.对风标花粉采样器采集的样品进行溶酸处理后进行花粉鉴定;对重力法采集的花粉样品染色后直接进行观察.利用高分辨的扫描电镜(SEM)对悬铃木花粉上吸附的大气颗粒物进行了微观表征.结果显示,上海春季大气中的花粉以木本植物花粉为主.不同区域悬铃木花粉上所吸附的颗粒物组分有所差异.冬季和春季大气颗粒物(总悬浮颗粒物)中的SO42-的浓度均为所检测离子(Na+、K+、Ca2+、Mg2+、NH4+、NO3-、SO42-、Cl-)中浓度最高的,NO3-、SO42-、NH4+在冬季样品中要比春季样品中的浓度高.上海大气颗粒物中的地壳元素的质量浓度从高到低为Ca >Na>Mg>K.     

空气微生物采样方法的比较

对3种空气微生物采样方法进行了比较。结果表明,在室外自然条件下,大气细菌粒子的沉降量与大气细菌粒子的浓度、大气真菌粒子的沉降量与大气真菌粒子的浓度均呈显著的正相关关系。对大气细菌粒子,用平皿沉降法分别与A·S采样器法、THK－201采样器法测定的结果相比,有非常显著的差异。平皿沉降法测定结果比后二者方法高出2.9倍和4.0倍;A·S采样器和THK－201采样器测定结果之间没有显著性差异。对大气真菌粒子,A·S采样器法和平皿沉降法与THK－201采样器法均有非常显著性差异;平皿沉降法与A·S采样器法测定结果之间没有显著性差异。进一步用直线回归分析的方法,得出了大气细菌粒子浓度与大气细菌粒子沉降量及大气真菌粒子浓度与大气真菌粒子沉降量之间的关系式。     

不同采样和保存方式测定非甲烷总烃比对研究

文章建立了以双柱双检测器气相色谱法对环境空气和污染源废气中的非甲烷总烃进行分析的方法。并且比较了注射器采样、真空瓶采样以及铝箔采气袋采样3种不同采样及其保存方式和时间对非甲烷总烃测定结果的影响。结果表明:对同一样品的采集和分析,是否避光保存和采样器具的材质对非甲烷总烃的浓度随时间变化的影响很大,无论非甲烷总烃的浓度大小如何,用玻璃器具对样品进行采集,在避光条件下进行保存,非甲烷总烃浓度随时间的降低百分比最低。     

水质自动采样器与手工采样测定结果对比与分析

在废水监测中，样品采集方法对能否客观地测定出水中污染物质的含量起到相当重要的作用，采集方法不当造成样品“失真”，以后的分析操作无论怎样认真，准确都毫无意义。自动采样器的应用是样品采集方法的一次飞跃，也是环境监测工作发展的需要。掌握水质自动采样器与现普遍采用的手工采样测定水中不同污染物的对比情况是自动采样器在实际应用的前提。     

不同级数的ANDERSEN生物粒子采样器采样效果的比较

用不同级数的 FA- 型、FA- 型和由 FA- 型 6级简化为 2级型的 3种类型的 ANDERSEN生物粒子采样器 ,在室内外对空气微生物粒子浓度、粒子大小分布的采样效果进行了比较 ,同时对 FA- 型生物粒子采样器的性能进行了检测。结果表明 ,5台 FA- 型生物粒子采样器的第 1级、第 2级采集的空气微生物粒子数和所占粒数百分比均无明显差别 ;逃失率为 3.3%。FA- 型和 FA- 型采样器对空气微生物粒子浓度的采样效果也没有明显差别 ;由 FA- 型 6级简化为 2级型的采样器与 FA- 型采样器对空气微生物粒子浓度和粒子大小分布的采样效果有明显差别 ,FA- 型采样器不宜简化为 2级型采样器使用     

采样时间对空气微生物采样效果的影响

用ＡＮＤＥＲＳＥＮ生物粒子采样器和微孔滤膜空气微生物采样器，在室内进行了不同采样时间对空气微生物采样效果的研究。结果表明，这两种采样器采集的空气微生物粒子浓度随采样时间增加而减少，呈明显的负相关关系，相关系数分别为：－０．８９８和－０．９１１，Ｐ值均小于０．０５。ＡＮＤＥＲＳＥＮ采样器采样时间〈７ｍｉｎ和微孔滤膜采样器采样时间〈３ｍｉｎ时，对采集的空气微生物粒子浓度没有明显影响。采样时间对采集的空     

南京大气PM10谱分布和细粒子中多环芳烃的研究

文章使用分级采样器采集夏秋两季南京市不同功能区的大气PM10样品,运用GC-MS等方法,研究细粒子中的多环芳烃(PAHs)的分布特征和污染来源。结果表明:各功能区秋季细粒子质量浓度均大于夏季,本底区细粒子质量浓度最低,为41.7～59.0μg/m3;交通商业区浓度最高,为206.5～467.0μg/m3。各功能区PM1...     

A multiple-system,multi-channel diffusion denuder sampler for the determination of fine-particulate organic material in the atmosphere

Measurement of the loss of semi-volatile organic compounds from particles collected with a filter is carried out by comparing the amounts collected by comparable filter pack and diffusion denuder samplers. The sorbents used to collect organic compounds in the denuder and sorbent filters must have the same efficiency for collection of all gas-phase organic compounds present. Interpretation of the data requires that the efficiency of collection of gas-phase compounds by the denuder be known. In theory this can be accomplished by determination of the deposition pattern of all organic compounds collected in the denuder, but in practice this is very difficult if the organic material consists of a wide variety of compounds. An alternative approach is to determine the breakthrough of organic compounds in a sampler with a particle-collection filter preceding the denuder and sorbent filter. In such a sampler only gas-phase organic material enters the denuder. We have developed both a multi-channel parallel plate diffusion denuder sampler and a comparable sampler in which the denuder is preceded by a filter. Samples can be collected with the multisystem sampler at a flow rate of 35 sLpm. The denuder surfaces and the sorbent filters are made from sheets of an activated charcoal-impregnated filter paper. Collection of semi-volatile compounds by the samplers has been characterized and the systems have been field tested. The samplers are now being used for the routine collection and determination of semi-volatile organic compounds in particles at Canyonlands National Park in southeastern Utah. Available data from this field program show significant losses of particulate organic compounds on a quartz filter due to volatilization during sampling.     

Equilibration times,compound selectivity,and stability of diffusion samplers for collection of ground-water VOC concentrations

Vapor-filled polyethylene diffusion samplers (typically used to locate discharge zones of volatile organic compound contaminated ground water beneath streams and lakes) and water-filled polyethylene diffusion bag samplers (typically used to obtain volatile organic compound concentrations in ground-water at wells) were tested to determine compound selectivity, equilibration times, and sample stability. The aqueous concentrations of several volatile organic compounds obtained from within water-filled diffusion samplers closely matched concentrations in ambient water outside the samplers. An exception was methyl-tert-butyl ether, which was detectable, but not reliably quantifiable using the diffusion samplers. The samplers equilibrated to a variety of volatile organic compounds within 24 h for vapor-filled passive diffusion vial samplers and within 48 h for water-filled passive diffusion bag samplers. Under field conditions, however, a longer equilibration time may be required to account for environmental disturbances caused by sampler deployment. An equilibrium period for both vapor- and water-filled diffusion samplers of approximately 2 weeks probably is adequate for most investigations in sandy formations. Longer times may be required for diffusion-sampler equilibration in poorly permeable sediment. The vapor-filled samplers should be capped and water from the diffusion bag samplers should be transferred to sampling vials immediately upon recovery to avoid volatilization losses of the gasses.     

The influence of outliers on results of wet deposition measurements as a function of measurement strategy

The results of a wet deposition monitoring experiment, carried out by eight identical wet-only precipitation samplers operating on the basis of 24 h samples, have been used to investigate the accuracy and uncertainties in wet deposition measurements. The experiment was conducted near Lelystad, The Netherlands over the period 1 March 1983–31 December 1985.By rearranging the data for one to eight samplers and sampling periods of 1 day to 1 month both systematic and random errors were investigated as a function of measuring strategy. A Gaussian distribution of the results was observed. Outliers, detected by a Dixon test (a = 0.05) influenced strongly both the yearly averaged results and the standard deviation of this average as a function of the number of samplers and the length of the sampling period. The systematic bias in bulk elements, using one sampler, varies typically from 2 to 20% and for trace elements from 10 to 500%, respectively. Severe problems are encountered in the case of Zn, Cu, Cr, Ni and especially Cd. For the sensitive detection of trends generally more than one sampler per measuring station is necessary as the standard deviation in the yearly averaged wet deposition is typically 10–20% relative for one sampler. Using three identical samplers, trends of, e.g. 3% per year will be generally detected in 6 years.     

污染场地土壤气中VOCs定量被动采样技术研究及应用

污染场地中土壤气样品的采集是蒸气入侵风险评估的关键,目前最常用的主动土壤气采集技术包括真空苏玛罐和泵吸附管,其操作繁琐、成本高、易受多种因素影响、只能采集短时间的浓度.土壤气定量被动采样技术是一种新兴的采样技术,很好地克服了主动式采样存在的不足,是目前污染场地中土壤气调查的研究热点.通过总结现有研究,就定量被动采样技术的理论、被动采样器吸附剂和外壳材料的选择、被动采样器吸附速率的研究及定量被动采样在污染场地中的应用进行论述.综合研究发现,只要严格控制吸附速率,被动采样能够提供准确的定量土壤气浓度测量;采样器结构的设计、外壳材料的选择能够有效控制吸附速率;吸附速率受环境因素和土壤性质的影响,场地校正是获得准确结果的有效途径.我国在土壤气采样领域的研究刚刚起步,建议:加大高效、广谱型或混合型吸附材料及相应测试方法和设备的研发;加强吸附速率的影响因子及场地校准方法的研究;加强土壤钻孔内土壤气的补给速率的模型和场地实测研究;增加不同种采样器的现场应用比较研究;进行适合我国国情的技术标准的研究与制订.      

大气飘尘冲击式分级采样器

本文分析了冲击式分级采样器的工作原理,对采样器中各种几率给予了严格的定义,阐明了这些几率概念之间的差别和相互联系,提出了多级采样器的研究简化为单级采样器研究的方法.提供了考虑粘性效应及用二种阻力公式(斯托克斯公式和标准阻力公式)的数值计算的P(Θ,Ω~*)曲线.对采样器工作特性曲线作了分析,指出各级主要采集粒径的范围大小和绝对收集几率的互相制约关系.提出采样器全面性能计算和设计方法.按本文提出的方法设计的LH-1型采样器,性能达到设计指标,已通过产品成果鉴定.     

哈尔滨市大气气相中多环芳烃的研究

在哈尔滨地区8个采样点同时安装了PUF大气被动采样器,研究了该地区2007年春季(1月末~4月末)大气气相中多环芳烃的含量和分布特征.结果表明,PUF大气被动采样器主要采集了大气气相中三环和四环的多环芳烃,占总量的91.22%~96.37%,PAHs的浓度具有明显的功能区差异,依次为:市区(356.49 ng/d),郊区(162.65 ng/d),农村(278.35 ng/d),偏远地区(183.99 ng/d),市区大气中多环芳烃的浓度是农村的2倍,偏远地区的3倍.污染源是影响大气中多环芳烃含量高低的主要因素,通过特征分子含量比值法对该地区大气中多环芳烃的来源进行了初步研究,结果表明,哈尔滨地区城市大气中多环芳烃主要来自于燃煤,农村大气中的多环芳烃主要来自于农作物秸秆的燃烧.利用毒性当量因子法对该地区大气气相中多环芳烃的健康风险进行了评价,具有与浓度分布类似的功能区差异,表明市区和农村地区大气中PAHs对于人们的健康存在较大潜在威胁.通过安装平行采样器,PUF被动采样器具有很好的重现性,研究表明,可以用于城市尺度多个采样点大气中多环芳烃的同时研究.     

Classification of residential exposure to nitrogen dioxide

In epidemiological studies of indoor nitrogen dioxide (NO₂) reported to date, only a limited number of measurements were made to estimate personal exposures. The accuracy of exposure estimates depends on the measurement error inherent in the samplers and in the sampling scheme. If categorical measures of exposure are used, the consequences of measurement error vary with classification rules. The effects of alternative measurement strategies on exposure classification were evaluated using NO₂ diffusion sampler measurements from 653 residences with gas cooking ranges. A time-series of consecutive 2-week integrated measurements was obtained for each home. During the winter season, the standard deviation was 26% of the mean. The probability of misclassification, a function of the mean and the standard deviation per home, was examined for three concentration classes (<25, 25–50, ⩾50 ppb). The average probability of misclassification was 10% for three 2-week integrated measurements across the winter and decreased to under 5% for continuous sampling (i.e. 13 consecutive 2-week samples). The sensitivity and predictive value were improved by increasing the number of samples obtained. The misclassification is determined by the number of concentration classes and by the relationship of class boundaries to the distribution of true means.     

燃煤污染源排放颗粒物采样方法实验室比对研究

为研究适用于我国燃煤污染源排放颗粒物的分级采样标准测试方法,采用民用小煤炉排放装置结合烟气采集系统,对比研究了直接采样法(双级虚拟撞击PM₁₀/PM_2.5采样器、旋风采样器、总烟尘采样器)和稀释采样法(低压荷电撞击器ELPI配备稀释系统)对烟气中不同粒径颗粒物测试结果的稳定性、相关性、仪器可操作性等特点,并分析了煤质对颗粒物分级测试结果的影响. 结果表明:①从决定系数和残差平方和角度分析,稀释采样法测试结果自身拟合性相对直接采样法差,实测数据点相对分散,95%置信带较宽. 直接采样法中,基于本文确定的清洗和收集方式,旋风采样器测试得到的PM₁₀和PM_2.5浓度拟合度高达0.999;双级虚拟撞击PM₁₀/PM_2.5采样器测试结果稳定性也较高,其测试得到的PM₁₀和PM_2.5浓度拟合度也为0.999. ②不同颗粒物采样器对烟气中PM_2.5、PM₁₀、TSP的浓度测试结果均表明,稀释采样法与直接采样法测试结果相关性较低;而各直接采样法之间呈高度相关,Pearson相关系数在0.993~0.999之间. ③稀释采样法分级测试结果显示,当颗粒物排放浓度较低时,各级滤膜称量误差叠加可导致PM₁₀、PM_2.5浓度测试结果误差较大. 因此,针对常温且颗粒物浓度较低的烟气,建议采用直接采样法;针对高温烟气,稀释采样法可捕集稀释降温过程中形成的可凝结颗粒物. ④各采样方法测试结果表明,相对于燃用无烟煤(如蜂窝煤),燃用烟煤产生的烟气中颗粒物浓度相对较高,且PM_2.5占比较高. 研究显示:稀释采样法能模拟燃煤污染源高温烟气排入大气环境中可凝结颗粒物的形成过程,测试结果更接近真实排放情况;对于常温颗粒物浓度较低的烟气,更适宜采用直接采样法.      

环境空气中醛酮类化合物检测方法优化与初步应用

环境空气中的醛酮类化合物是当今大气环境科学领域的研究热点.醛酮类化合物因反应活性较高、性质不稳定,导致检测较为困难.为准确测定环境空气中的醛酮类化合物,针对环境空气中质量浓度较高或活性较强的18种醛酮类化合物的采样和分析方法进行研究,并采用优化的方法于2018年5月对北京市典型城区环境空气中的醛酮类化合物进行了检测.结果表明:①与手动采样器同时同地点采样数据相比,自行制作的醛酮类化合物自动采样器能够实现连续采样,数据基本一致（R2为0.999 7）,其采样流速最大不超过0.8 L/min;醛酮类化合物采样管中杂质含量最高的乙醛为0.01 μg/管,小于我国HJ 683-2014《环境空气醛、酮类化合物的测定高效液相色谱法》标准限值（0.10 μg/管）.②采用所确定的二醛类化合物衍生化方法与质谱扫描条件可以成功检测乙二醛和甲基乙二醛两种二醛类化合物,建立了18种醛酮类化合物的标准曲线且标准曲线相关系数R2均大于0.995 0.③采用该优化方法得到北京市典型城区环境空气中18种醛酮类化合物质量浓度的日变化范围为17.73~88.42 μg/m3.      

Field intercomparison of filter pack and denuder sampling methods for reactive gaseous and particulate pollutants

Atmospheric sulphate, nitrate, chloride and ammonium species have been measured with colocated filter pack and denuder samplers. In general the total amount of a species collected by the two types of sampler was almost the same, although there was evidence of better inlet efficiency for particles in the filter pack sampler. The filter pack gives slightly higher measurements of the volatile species HNO₃, HCl and NH₃ than the denuder, with a corresponding lower measure of particulate NO₃⁻, Cl⁻ and NH₄⁺, attributable to volatilization of ammonium salts from the filter pack pre-filter. In the context of most ambient measurements, the divergences between the techniques are small, and it is argued that differences in these measurement techniques are inevitably site, operator and apparatus-specific and data from one site or research group cannot readily be extrapolated to other sites.