环境空气连续自动监测系统性能审核相关问题探讨

为独立评估环境空气连续自动监测系统运维质量,掌握环境空气监测数据准确性等信息,我国开展了环境空气连续自动监测系统性能审核工作,通过分析影响审核结果的相关因素,提出,性能审核标准气体浓度应接近实际监测空气中的气体浓度,性能审核时间的选择应满足《环境空气质量标准》(GB 3095—2012)中数据统计的有效性规定,性能审核气体压力应保持恒定并接近实际采样时的气压,标准气体进样方式应通过日常采样管路等,从而进一步提高性能审核结果的科学性和准确性,为生态环境管理部门了解环境空气数据质量提供坚实基础。     

室内空气颗粒物中HCHs和DDTs的含量

采用中流量TSP采样器在北京大学住宅小区和教学楼同步采集了室内和室外的大气颗粒物样本 ,分析了其中的HCHs和DDTs残留量 .结果表明 :室内外大气颗粒物中∑HCH的含量分别为 0 1 39ng·m- 3和 0 1 63ng·m- 3,∑DDT含量为 0 40 1ng·m- 3和 0 42 4ng·m- 3.室内外的浓度差别不大 .但由于室内空气颗粒物含量显著低于室外 ,其颗粒物中HCHs和DDTs的质量浓度显著高于室外 ,这可能与室内颗粒物的粒径较小有关 .考虑到室内外空气颗粒物中有机氯异构分布的相似性 ,居住区室内空气颗粒物中的HCHs和DDTs主要来自室外 .而实验室内空气在一定程度上受HCHs内部源污染 .     

Measurements of peroxyacyl nitrates (PANS) in Mexico City: implications for megacity air quality impacts on regional scales

Peroxyacyl nitrates (PANs) were measured using gas chromatography with electron capture detection (GC/ECD) in north central Mexico City during February–March of 1997. Peroxyacetyl nitrate (PAN) was observed to exceed 30 ppb during five days of the study, with peroxypropionyl nitrate (PPN) and peroxybutryl nitrate (PBN) reaching 6 and 1 ppb maximum, respectively. Levels of total PANs typically exceeded 10 ppb during the period of measurement and showed a very strong diurnal variation with PANs maximum during the early afternoon and falling to less than 0.1 ppb during the evening hours. These levels of PANs are the highest reported values in North America (and the world) for an urban center, since levels of approximately 30 ppb were reported during the late 1970s in the Los Angeles area (South Coast Air Basin, Tuazon et al., 1978). Hydrocarbon measurements indicate that the levels of olefins, specifically butenes are significant in Mexico City. A time series taken of source indicator hydrocarbons taken before and during a Mexican National Holiday with reduced automobile traffic clearly show that mobile sources of butenes are as important as liquefied petroleum gas. Observations of 10–40 ppb C methyl-t-butyl ether (MTBE) are consistent with MTBE/gasoline fuel usage as a source of isobutene and formaldehyde. Both these reactive species can lead to increased oxidant and PAN formation. The strong diurnal profiles of PANs are consistent with regional clearing of the Mexico City air basin on a daily basis. Estimates are given using a simple box model calculation for a number of key primary and secondary pollutant emissions from this megacity on an annual basis. These calculations indicate that megacities can be important sources of both primary and secondary pollutants, and that PANs produced in megacity environments are likely to contribute strongly to regional scale ozone and aerosol productions during long range transport.     

Composition of extractable organic matter in aerosols from urban areas of Rio de Janeiro city, Brazil

The hydrocarbon compositions of atmospheric particulate matter from urban areas of Rio de Janeiro city have been studied to assess the different pollution levels. Samples were acquired using a standard high-volume air sampler (Hi-Vol), extracts were prepared and fractionated into aliphatic and aromatic compounds. High-resolution gas chromatography and GC coupled to mass spectrometry (GC–MS) were used for the analysis of the organic matter. The results show that all samples contain n-alkanes, but the distributions are different for each sample, reflecting both the biogenic (vascular plant wax input) and fossil fuel contamination sources (vehicular exhaust). The fossil fuel biomarkers, hopanes and steranes, were also observed in all samples except in the Tijuca Forest, which is a mountain forest in the midst of the sea-level city. A decrease in the level of pollution was observed in the sequence for Rebouças Tunnel>Cinelândia (downtown)>Quinta da Boa Vista Park>Tijuca Forest, as expected from the traffic density. Unfortunately, all sites are polluted mainly from vehicular emissions, but at different degrees, with the lowest levels in Tijuca Forest.     

活性炭吸附室内空气中挥发性有机化合物

活性炭吸附室内空气中挥发性有机化合物的１０％穿透时间与气相浓度及挥发性有机化合物的种类有关,通过对苯、甲苯和丙酮的实验研究,得出了由高浓度估算室内低浓度时炭床１０％穿透时间的经验公式ｔｂ,１＝ｔｂ,ｈ（Ｃ０,１／Ｃ０,ｈ）＾ａ,其中ａ值是与炭床性能及挥发性有机化合物种类有关的参数,可通过实验确定。     

空调车间的通风除尘设计

针对空调车间的通风除尘,阐述了确定系统风量的方法。     

Establishing a Regional Monitoring Strategy: The Pacific Northwest Forest Plan

adaptive monitoring design. Adaptive monitoring design is an iterative process that refines the specifications for monitoring over time as a result of experience in implementing a monitoring program, assessing results, and interacting with users. An adaptive design therefore facilitates ecosystem management. We also discuss lessons of temporal and spatial scales raised by the consideration of a design for ecosystem management. Three additional issues—integration of information from different sources, institutional infrastructure, and the roles of individuals working in an interagency setting—are also identified, but not developed in detail.     

90锶在核排污水域中的分布与监测

本文报告了川江上游核排污水环境中９０ Ｓｒ 的监测结果。表明：９０ Ｓｒ 在河水和底泥中的含量与排污距离密切相关,在不同水生物种之间的蓄积分布有显著性差异,其中底泥和含钙高的生物对９０ Ｓｒ 有较强的浓集作用。所以,选用指示性物种能提高９０ Ｓｒ 监测灵敏度,是核污染监测的较好方法。     

废水监测分析的系统化问题

详细、全面地阐述了废水监测工作系统应具备的基本条件和设施及各个环节之间的协调配合关系,指出了该系统管理中应注意的主要问题。     

浅议环境监测档案的建立和运用

通过分析目前环境监测站监测档案建立和运用中存在的问题,探讨了档案的建立方法及在环境监测和环境管理中的运用。