河南省典型城市PM2.5无机元素污染特征及来源分析

分析2012年采暖季和非采暖季郑州市、洛阳市和平顶山市大气细颗粒物(PM_(2.5))样品中22种无机元素含量和污染特征,采用富集因子法、因子分析法研究当地PM_(2.5)中无机元素来源。结果表明:3个城市PM_(2.5)中无机元素总量在采暖季均高于非采暖季,不同季节占PM_(2.5)质量浓度的比例为1.7%~3.6%。Al、Na、Ca等地壳元素在PM_(2.5)中占比与PM_(2.5)浓度呈负相关关系,而Zn、Pb、Cu等人为源元素的占比随PM_(2.5)浓度增加无明显下降趋势。3个城市PM_(2.5)中Se、Cd、Br的富集因子高于1 000,Pb、Zn、Cu的富集因子为100~1 000,Co、Sc、Cr、Ni、As、Mn、Ba的富集因子为10~100,说明这些元素主要来源于人为源。13种人为源元素质量浓度在22种元素中占比为18.9%~26.3%,K、Fe、Ca、Al等4种元素占比为67.9%~76.1%。因子分析结果表明:3个城市无机元素来源组成有很大相似性,主要来源于燃煤、机动车、扬尘和建筑尘等,但Ni、Co、Sr、Ba还有来自其他排放源的贡献。     

2020年泰州市细颗粒物质量浓度高值区污染来源解析

2020年在位于泰州市主城区大气细颗粒物(PM_(2.5))质量浓度高值区的莲花国控空气站点进行手工采样,分析了大气PM_(2.5)的质量浓度和元素组成,以及离子、有机碳和元素碳的质量浓度。根据监测结果,采用正定矩阵因子分解(PMF)受体模型对其来源进行解析。结果显示,莲花站点大气PM_(2.5)中主要组分包括有机物、硝酸盐、硫酸盐、铵盐、地壳物质、氯盐、钾盐、黑炭、微量元素和钠盐,占比分别为35.7%,25.6%,13.9%,11.9%,6.1%,2.3%,1.5%,1.5%,0.8%和0.7%,有机物、硝酸盐、硫酸盐、铵盐为首要污染组分,这4类物质对PM_(2.5)的累计贡献为87.1%。根据解析结果与实际污染特征,提出应优化城市路网结构,强化工地扬尘管控,全面取缔燃煤炉和严抓秸秆禁烧工作等控制对策。     

抚顺市PM10中元素分布特征及来源分析

为了确定抚顺市PM10中元素的浓度特征及其来源,于2006—2007年的采暖季、风沙季和非采暖季在抚顺市的6个采样点采集PM10样品,并用等离子体原子发射光谱法(ICP-AES)测定样品中Ti、Al、Mn、Mg、Ca、Na、K、Cu、Zn、As、Pb、Cr、Ni、Co、Cd、Fe、V等17种元素的含量。结果表明,Al、Mg、Ca、Na、K、Mn、Fe等地壳元素在17种元素中占有较大比重,全年平均达到97.0%。富集因子分析结果表明,Cu、Zn、Pb、Cr、Co、Cd等元素在各季和各采样点明显受到人为活动影响,是典型的污染元素。主因子分析结果显示,土壤风沙尘、建筑尘、燃煤尘、道路扬尘、机动车尾气排放、金属冶炼、锰、铜、钛工业源是抚顺市PM10中元素的主要来源。     

青藏高原典型城市拉萨市大气颗粒物污染源成分谱建立研究与特征分析

系统研究建立高原典型城市拉萨市开放源(土壤风沙尘、道路扬尘、施工扬尘、采矿扬尘),移动源(机动车尾气尘),固定源(工业烟粉尘、生物质燃烧尘及餐饮油烟)共3类8种大气颗粒物(PM_(2.5)、PM_(10))污染源化学成分谱。研究结果表明:开放源以地壳类元素为主,自然背景特征明显;移动源源成分谱中元素碳含量明显高于其他城市,在PM_(2.5)、PM_(10)源谱中分别占60.15%、51.86%,有机碳含量也相对较高,均超过20%;固定源中,牛粪和松柏枝两类生物质燃烧污染源的有机碳含量显著高于其他组分,工业烟粉尘中Ca远高于其他组分,在PM_(2.5)、PM_(10)源谱中分别占21.32%、21.21%。移动源、固定源源成分谱均显示出高原城市的独特特征。     

Determination of total and partially extractable solid-bound element concentrations using collision/reaction cell inductively coupled plasma-mass spectrometry and their significance in environmental studies

Determination of solid-bound element concentrations is an important initial step in environmental studies especially for assessment of contamination level, and of origin, relative mobility, and fate of contaminants. This study revealed that a relatively new collision/reaction cell inductively coupled plasma-mass spectrometry is a potent tool for determining total and partially extractable solid-bound element (V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, and Pb) concentrations in a complex matrix solution containing HF and/or HCl. Six different extraction methods commonly used for environmental monitoring studies were tested for their bias and variability using estuarine and marine standard reference materials. Microwave-assisted methods based on concentrated [HNO₃] or [HNO₃?+?HF (4:1)] and [HNO₃?+?HF?+?HCl (10:3:2)] were applied for determining pseudo-total and total element concentrations, respectively. Dilute-acids (1 M HNO₃, 1 M HCl, and 0.5 M HCl) were utilized in single-step partial extraction protocols. Except the 0.5 M HCl cold-extraction method which was performed at room temperature, other partial extraction protocols used microwave-digestion. This study demonstrated that the use of microwave-assisted methods in studies aimed at determining the non-residual, non-specific extractable fractions of elements in solid environmental samples may result in overestimation, and thus needs to be re-examined. We believe that the cold extraction method will play a significant role in future environmental monitoring studies. Nevertheless, results of the cold extraction method not accompanied with total element concentrations have limited value, as the amount of extraction may vary significantly with the nature (origin) of the elements, and with the types of the samples. Therefore, we suggest combining microwave-assisted total digestion and 0.5 M HCl cold-extraction methods as a relatively cost- and time-effective, environmentally sound screening procedure for routine environmental monitoring programs involving a large number of samples from diverse geological and anthropogenic settings.     

PM2.5手工监测技术要点探讨

以重量法为原理的手工监测法是国内外监测环境空气PM2.5质量浓度的标准方法,在空气质量监测中具有重要应用。该文以2012年跨4个季度近150 d的PM2.5手工监测实际操作经验为基础,重点探讨了手工监测法各环节的监测技术要点,如手工监测采样器的操作技术、滤膜种类的选择及前处理要求、滤膜更换技术、滤膜平衡和称重条件、质量保证和质量控制技术等,以期为推广PM2.5手工监测法提供技术参考。     

Effect Of Reagent (Dye) Addition In Wet Chemical Method Of Sulfur Dioxide Determination In Ambient Air

For measurement of sulfur dioxide (SO₂) in ambient air, the United States Environment Protection Agency (US EPA) had recommended the PRA dye-based colorimetric method as a reference technique. The method has been developed and applied in many countries for a longtime; however information regarding the sensitivity of the method with respect to sampling and analysis conditions is not available. Collaborative studies conducted in some of the South East Asian countries indicated substantial variations (of the order of 50%) in the measured concentrations against the true values. It was observed that dye used for color development plays an important role and even a slight variation in the way the dye solution is prepared can cause substantial variation in the measured SO₂ concentration. Because a major objective of air quality measurements is to relate air pollution concentration to the effects of air pollution, it is important that the method used should yield accurate levels of the pollutant, so that appropriate management plans can be devised and implemented effectively. In the present investigation, therefore, the role of dye used in SO₂ monitoring method has been highlighted. Different makes of dyes prepared in different modes were used to study the variation in the measured SO₂ concentration levels. Specifications of all the dyes were also tested. Need for use of certified reference material (CRM) for SO₂ has also been emphasized.     

波长色散-X射线荧光光谱法测定PM2.5中23种元素

研究以单元素标准膜为基础，结合NIST SRM 2783颗粒物滤膜标准样品，建立了波长色散-X射线荧光光谱法测定PM_2.5中23种无机元素的测定方法，优化了测试条件，测量一个样品耗时约15 min，计算了各元素的方法检出限。对NIST SRM 2783滤膜标准品在一周内重复测定10次来计算方法的准确度与精密度，测定结果显示大多数元素的测量值在给出的参考值范围内，且测量标准偏差一般在10%以内。对比了石英与聚四氟乙烯材质（Teflon）滤膜的空白值，石英滤膜中Si、Fe、Na、Mg、Al、K、Ca等元素的背景值较高，Teflon滤膜的背景值较低，推荐选用Teflon滤膜作为PM_2.5组分分析采样滤膜。分别用波长色散-X射线荧光光谱法及酸消解-ICP-MS法测定了样品膜中的元素组分，得到的测定结果基本一致。     

重庆城区不同粒径颗粒物元素组分研究及来源识别

为研究重庆市大气颗粒物的污染特征及其来源,于2010年3—10月在主城区分别采集PM_1.0、PM_2.5和PM₁₀3种粒径的颗粒物样品,利用XRF分析其中的26种元素浓度。结果表明,重庆市主城区S元素在各粒径中含量都较高,细粒子中K的含量较高,粗粒子中Si、Ca和Fe的浓度较大。富集因子分析表明,主城区Cd、S、Se等污染元素的富集系数较大,且粒径越小,富集现象越明显。利用因子分析得出土壤风沙、扬尘、燃煤的燃烧、机动车燃油产生的尾气排放、生物质燃烧排放是重庆市颗粒物污染的主要来源。     

微波消解ICP-MS法测定宣威和富源土壤中的微量元素

建立了微波消解-ICP-MS法测定土壤中32种微量元素的方法。采用氢氟酸-硝酸-过氧化氢体系微波消解,稀释定容后用ICP-MS对溶液进行元素的测定,在优化仪器工作参数后,以双内标铑(Rh)和铼(Re)进行校正。元素检出限为0.01～0.45ng/ml,测定国家标准物质西藏土壤成分分析标准物质GBW 08302中的元素,测定值与标准值或参考值基本一致,用该法测定云南宣威和富源两地24份土壤样品结果表明,该方法快速、简便、准确,适于土壤中多种微量元素的测定。     

某集中式饮用水源地保护区土壤重金属监测与评价

采用现场采样与室内测试方法测定了某大型集中式饮用水源地一级保护区土壤中Cd、Hg、As、Pb、Cr、Cu、Zn和Ni的含量,利用污染指数法、地累积指数法和潜在生态指数法对其土壤环境质量进行了评价。结果表明,上述8种重金属都存在不同程度的超标,其中Cd超标最为严重。地累积指数法评价结果表明,研究区只有Cd、Hg存在一定污染,污染程度分别为中度污染到强污染、中度污染和中度污染到强污染。潜在生态指数法结果表明:研究区土壤样品Cd的单因子潜在生态风险指数最高,轻微、中等和较高风险等级中所占比例分别为44.7%、23.7%、31.6%;其次为Hg,有89.5%的土壤样品中Hg处于轻微生态风险水平,10.5%的土壤样品处于中等生态风险水平;土壤样品中As、Pb、Cu、Ni、Zn、Cr都处于轻微生态风险水平。Cd是研究区最主要的污染和生态风险因子,其次是Hg,说明集中式饮用水源地保护区土壤已受到个别重金属的影响。虽然目前尚不存在饮用水源地水体受污染问题,但应引起高度关注。     

北京地区不同季节PM2.5和PM10浓度对地面气象因素的响应

利用2013年1月—2014年12月北京地区PM_(2.5)和PM_(10)监测数据和同期近地面气象观测数据,采用非参数分析法(Spearman秩相关系数)研究了北京地区PM_(2.5)和PM_(10)的浓度对不同季节地面气象因素的响应。结果表明:北京地区大气颗粒物浓度水平具有明显的季节特征,冬季大气颗粒物污染最严重,夏季最轻。不同季节影响颗粒物浓度水平的气象因素各不相同,其中风速和日照时数为主要影响因素。PM_(2.5)和PM_(10)质量浓度对气象因素变化的响应程度也有较大区别,PM_(2.5)/PM_(10)比值冬季最高,PM_(2.5)影响最大,春季最低,PM_(10)影响最大。这些结论可对制订科学有效的大气污染控制策略提供参考。     

Seasonal Variation of Chemical Composition in Fine Particles at Gosan, Korea

PM_2.5 aerosol samples were collected at Gosan in Jeju Island during six intensive measurement periods between November 2001 and August 2003. In order to investigate the chemical composition of fine particles, major ion components, trace elements, and elemental and organic carbon were analyzed. Quite different seasonal characteristic in the chemical composition of fine particles was observed. The concentration of most secondary aerosol components showed a summer minimum and a winter maximum with higher correlation between them at Gosan. This fact clearly reveals the possibility of long-range transport of such pollutants in winter. On the other hand, OC and EC had the highest concentration and good correlation with ion components, such as K⁺, Ca²⁺ in fall. It means that biomass burning could significantly influence the ambient fine carbonaceous particulate in fall, which was primarily long-range transported.     

Gravimetric and Chemical Features of Airborne PM10 AND PM2.5 in Mainland Portugal

This paper describes concentration amounts of arsenic (As), particulate mercury (Hg), nickel (Ni) and lead (Pb) in PM₁₀ and PM_2.5, collected since 1993 by the Technological and Nuclear Institute (ITN) at different locations in mainland Portugal, featuring urban, industrial and rural environments, and a control as well. Most results were obtained in the vicinity of coal- and oil-fired power plants. Airborne mass concentrations were determined by gravimetry. As and Hg concentrations were obtained through instrumental neutron activation analysis (INAA), and Ni and Pb concentrations through proton-induced X-ray emission (PIXE). Comparison with the EU (European Union) and the US EPA (United States Environmental Protection Agency) directives for Ambient Air has been carried out, even though the sampling protocols herein – set within the framework of ITN's R&D projects and/or monitoring contracts – were not consistent with the former regulations. Taking this into account, 1) the EU daily limit for PM₁₀ was exceeded a few times in all sites except the control, even if the number of times was still inferior to the allowed one; 2) the EU annual mean for PM₁₀ was exceeded at one site; 3) the EPA daily limit for PM_2.5 was exceeded one time at three sites; 4) the EPA annual mean for PM_2.5 was exceeded at most sites; 5) the inner-Lisboa site approached or exceeded the legislated PMs; 6) Pb levels stayed far below the EU limit value; and 7) concentrations of As, Ni and Hg were also far less than the reference values adopted by EU. In every location, Ni appeared more concentrated in PM_2.5 than in coarser particles, and its levels were not that different from site to site, excluding the control. The highest As and Hg concentrations were found in the neighbourhood of the coal-fired, utility power plants. The results may be viewed as a “worst-case scenario” of atmospheric pollution, since they have been obtained in busy urban-industrial areas and/or near major power-generation and waste-incineration facilities.     

西宁市城区冬季PM2.5和PM10中有机碳、元素碳污染特征

2014年11月—2015年1月对西宁市冬季开展PM_(2.5)和PM_(10)的连续监测。利用DRI 2001A型热光碳分析仪(美国)对有机碳和元素碳进行分析,结果表明:西宁市冬季PM_(2.5)和PM_(10)中碳气溶胶所占比例分别为33.13%±6.83%、24.21%±6.27%,说明碳气溶胶主要集中在PM_(2.5)中;OC/EC值均大于2,说明西宁市大气中存在二次污染;SOC占PM_(2.5)和PM_(10)的质量浓度比例分别为46.50%和57.40%,PM_(2.5)中SOC浓度占PM_(10)中SOC浓度的61.88%,说明SOC主要存在于PM_(2.5)中,且SOC形成的二次污染和直接排放的一次污染都是西宁市碳气溶胶的主要来源;与其他城市比较发现,西宁市冬季PM_(2.5)中的碳气溶胶含量普遍高于其他城市,PM_(10)中OC质量浓度相对其他城市较高,EC质量浓度偏低;OC和EC的相关性不显著,说明来源不统一;进一步对OC和EC各组分质量浓度进行分析知,西宁市冬季碳气溶胶主要来源于机动车汽油排放、燃煤和生物质燃烧。     

合肥市冬季细颗粒物中碳组分特征分析

利用2020年12月1日至2021年2月28日合肥市细颗粒物(PM_2.5)、有机碳(OC)和元素碳(EC)等环境空气质量监测数据和气象观测数据，分析了合肥市大气PM_2.5中OC和EC的污染特征，并探讨了其来源以及气象因素影响。结果表明：合肥市冬季碳质气溶胶是PM_2.5中主要组分，随着污染程度的加重，碳质气溶胶的质量浓度逐步增加，但其在PM_2.5中的占比先减小后增加。在以PM_2.5为首要污染物的不同污染级别天气条件下，OC和EC的相关性说明不同程度下碳质气溶胶来源复杂。OC/EC表明机动车尾气和燃煤源排放是碳质气溶胶的主要来源。二次有机碳(SOC)会随着污染程度的加重而呈现升高趋势。OC和EC在冬季受温度影响较小；较大的相对湿度对OC和EC具有一定的清除作用，明显降水或连续降水的清除作用更加显著；而风速对含碳气溶胶的影响主要出现在污染天气背景下。     

环境监测用高锰酸盐指数和氨氮标准溶液量值比对研究

针对高锰酸盐指数(COD_Mn)和氨氮(NH₃-N)标准溶液(以下简称液标)制造商、浓度水平和使用情况进行调研,根据调研结果选择常用的7个品牌COD_Mn液标和9个常用NH₃-N液标品牌开展量值比对和质量评价研究,匿名采购129支液标经盲样编码后采用《地表水环境质量标准》(GB 3838—2002)推荐标准进行分析测定,计算和评定测定结果的不确定度,以En法进行量值比对评价。研究表明,NH₃-N液标量值均满意,COD_Mn测试中的加盖操作会使测定结果偏高,按照证书要求操作时COD_Mn液标量值合格,未按照液标证书中要求进行液标样品前处理测定会造成测定结果的偏离,影响评价结果。建议监测人员合理选用和规范使用环境用液标,加强环境用液标的选购和管理,确保检测过程得到有效控制。     

PM2.5 and PM10 Concentrations from the Qalabotjha Low-Smoke Fuels Macro-Scale Experiment in South Africa

This article presents results from the particulate monitoringcampaign conducted at Qalabotjha in South Africa during the winter of 1997. Combustion of D-grade domestic coal and low-smoke fuels were compared in a residential neighborhood to evaluate the extent of air quality improvement by switchinghousehold cooking and heating fuels.Comparisons are drawn between the gravimetric results from the two types of filter substrates (Teflon-membrane and quartz-fiber) as well as between the integrated and continuous samplers. It is demonstrated that the quartz-fiber filters reported 5 to 10% greater particulate mass than the Teflon-membrane filters, mainly due to the adsorption of organic gases onto the quartz-fiber filters. Due to heating of sampling stream to 50 °C in the TEOM continuous sampler and the high volatile content of the samples, approximately 15% of the particulate mass was lost during sampling.The USEPA 24-hr PM_2.5 and PM₁₀ National Ambient Air Quality Standards (NAAQS) of 65 g m^-3 and 150 g m^-3, respectively, were exceeded on several occasions during the 30-day field campaign. Average PMconcentrations are highest when D-grade domestic coal was used, and lowest between day 11 and day 20 of the experiment when a majority of the low-smoke fuels were phased in. Source impacts from residential coal combustion are also found to be influenced by changes in meteorology, especially wind velocity.PM_2.5 and PM₁₀ mass, elements, water-soluble cations (sodium, potassium, and ammonium), anions (chloride, nitrate, and sulfate), as well as organic and elemental carbonwere measured on 15 selected days during the field campaign. PM_2.5 constituted more than 85% of PM₁₀ at three Qalabotjha residential sites, and more than 70% of PM₁₀ at the gradient site in the adjacent community of Villiers. Carbonaceous aerosol is by far the most abundant component, accounting for more than half of PM mass at the three Qalabotjha sites, and for more than a third of PM mass at the gradient site. Secondary aerosols such as sulfate, nitrate,and ammonium are also significant, constituting 8 to 12% of PM mass at the three Qalabotjha sites and 15 to 20% at the Villiers gradient site.     

两种消解法测定沉积物总磷的对比

通过过硫酸钾消解法与HClO₄-H₂SO₄消解法对土壤和水系沉积物的标准物质,以及三峡水库沉积物未知样品中的总磷含量进行测定,并对检测结果进行对比,分析过硫酸钾消解法测定沉积物总磷的可行性。结果表明,在标准样品中,HClO₄-H₂SO₄消解法的检测结果是标准值的83%~100%,并且所有结果均在其不确定度范围之内;过硫酸钾消解法的检测结果仅达到标准值的19%~42%,超出其不确定度范围,不能作为有效数据。在未知样品中,过硫酸钾消解法检测结果也远低于HClO₄-H₂SO₄消解法检测结果,只达到后者的32%~52%。由此可见,过硫酸钾消解法测定沉积物或土壤中总磷,仍需要进一步的研究,以达到符合实际的检测结果。     

Inter-Laboratory Comparison of No2 and SO2 Generated by Dynamic Dilution System Under Laboratory Conditions: A Technical Discussion

A workshop on analytical quality control (AQC) of ambient air quality measurement methods for nitrogen dioxide (NO₂) and sulphur dioxide (SO₂) was conducted by Central Pollution Control Board (CPCB) for officials involved in National Ambient Air Quality Monitoring (NAAQM) in India. Concentrations of NO₂ and SO₂ were generated by dynamic dilution system under laboratory conditions at low and high levels and measured using static dilution system and wet chemical methods laid down by CPCB under section 16(2)(h) of the air act 1981. CPCB provided the measured values as reference values for comparing the means obtained by the officials participated from thirteen organizations. A tolerance limit of ±15% of the reference values was specified to accept the results. Generated concentrations, which were unknown to the participants, were measured using gaseous sampling assembly (Envirotech APM 411, New Delhi, India), and wet chemical methods laid down by CPCB i.e. the same methodology which is used by the organizations to generate the data of NO₂ and SO₂ in ambient air. Simultaneously, concentrations were checked by CPCB using automatic analyzers as a check on reference concentration. It is observed that results of automatic analyzers for NO₂ and SO₂ were within a tolerance of ±5% with %RSD below 3. On the other hand, results of most of the participants showed variability in the measurements with %RSD ranging between ±0.8 and ±88.6 and exceedences of means from the tolerance limit with bias ranging between 1.4 and −59%. To check the cause of high variability in the measurements obtained under identical conditions, duplicate sampling was performed by one of the participants for SO₂ at low concentration level. In this study, results of wet chemical methods, automatic analyzers and results of duplicate sampling are analysed statistically to assess the cause of high variability in the measurements. Analysis of t-test and analysis of variance (ANOVA) showed highly significant results for NO₂ and SO₂ at high concentration levels (α 0.05) and for SO₂ at both the levels (α 0.01) respectively indicating some bias is existing either in the sampling or in analytical technique. Duplicate sampling performed to check precision in parallel measurements showed high %RSD indicating the presence of systematic error in sampling technique as the same calibration factor (CF) was used to measure the concentration of duplicate samples. Statistical analysis of flow rates of duplicate sampling showed that the sampling assembly could not maintain the constant flow rate within the ±10% with that measured at the start of the sampling. This resulted in high %RSD and deviation from the reference values for the results of most of the participants, even after accepting ±15% tolerance limit. There is a need to improve and evaluate this gaseous sample collection device under laboratory conditions to generate reliable database of NO₂ and SO₂ in ambient air.