末梢水与水源水数据“倒挂”现象探讨

末梢水与其水源水的数据“倒挂”现象是影响居民饮水健康的安全隐患。基于末梢水数据“倒挂”现象在新闻报道、政府信息公开及相关调查研究中的表现形式,分析了引起末梢水数据“倒挂”的原因主要包括：监测采样、分析偏差,物理因素和化学、生物反应以及综合因素造成的污染等。提出,在饮用水水源方面,加强规范化管理,保持水源水水质合格并长期稳定;在水处理阶段,选择适宜且安全高效的水处理方式;在水管输送阶段,选择健康的管道材质并合理规划设计、维护输水管网体系;在饮用水使用阶段,加强用水宣传,让居民养成良好的健康用水习惯。从而逐渐消除末梢水数据“倒挂”现象,保障居民的饮水安全。     

大气颗粒物源解析土壤风沙尘成分谱研究进展

土壤风沙尘是颗粒物源解析的一类重要尘源,文章从概念、成分、粒径、采样、区域性特征、标识元素选择、成分谱比较、影响因素、数据库建设等几个方面介绍了土壤风沙尘的研究进展。     

Airborne fine particulate matter (PM2.5) at industrial,high- and low-density residential sites in a Nigerian megacity

Abstract

Airborne particulate matter PM_2.5 was collected in an industrial, a low-density, and a high-density residential area of Lagos from December 2010 to November 2011, and elemental composition was determined by proton-induced X-ray emission. Across the months, mass concentrations ranged from 13 to 237?µg?m^?3, exceeding the World Health Organization guideline value of 10?µg?m^?3. Data on 24 elements were obtained, with maximum values during Harmattan season months; source identification and apportionment studies by positive matrix factorization suggested that petroleum oil combustion (70%) was the major source of PM_2.5 and could pose a great hazard to Lagos receptors.     

Free or low-cost geoinformatics for disaster management: Uses and availability issues

The disaster management applications of geographical information systems and remote sensing are examined relative to the disaster cycle, in pre-disaster, crisis and post-disaster contexts. We focus on the uses and limitations of free or low-cost data and software. A wide range of geospatial datasets are currently freely available, from digital elevation models (DEMs) and thematic digital maps, to multispectral satellite imagery and virtual globes, such as Bing Maps. Maps of hazardous terrain and vulnerable features can be derived from sets of satellite data such as shuttle radar topography mission DEMs and Landsat imagery. The derived maps are particularly useful for district scale (1:25 to 1:100 K) disaster management in low-income countries. Detailed maps (i.e. better than 1:25 K scale) of hazardous terrain and vulnerable features generally require expensive high-resolution satellite imagery or aerial photography.

Although the Internet allows the distribution of free or low-cost geospatial data, software and training materials, there are still some countries with limited Internet access. Data integration, spatial/temporal analysis and map production are also limited by the frequently high price of geoinformatic software, making it a priority to develop suitable Free and Open-Source Software.     

吉林省典型城市大气中PAHs来源解析

通过对吉林省4个典型城市,即吉林、白城、四平和通化市大气颗粒物中多环芳烃（PAHs）的采样和分析,得到16种PAHs的成分谱,应用主因子分析和特征比值法对其进行定性研究,得到吉林省大气中PAHs的2种主要来源--车辆尾气和燃煤。并应用绝对主因子分析法进一步定量计算这2种源对PAHs的浓度贡献值及贡献率,结果表明：吉林省典型城市PAHs解析值为772.39μg·g-1,绝大多数解析值与监测值之间的比值接近于1,车辆尾气对各PAH的贡献率为2.6%~67.6%,燃煤源的贡献率为24.1%~121.2%。另外,该研究还计算了已识别的2种源对于不同环数的PAHs的贡献,2~3环的PAHs大部分来自于燃煤,约占总体的89%,车辆尾气仅占11%;4环的PAHs约58%来源于燃煤,42%来源于车辆尾气;5环的PAHs约45%来源于燃煤,55%来源于车辆尾气;6环PAHs来源于燃煤的占61%,来源于车辆尾气的占39%。     

武汉秋冬季大气PM2.5中多环芳烃的分布特征及来源

采集了2011—2012年武汉市工业区、交通区和植物园的3个功能区的秋冬2季大气PM2.5样品,采用超声提取预处理和GC/MS分析检测了PM2.5中27种PAHs,探讨了其时空分布特征,然后运用主成分分析/多元线性回归法解析了PAHs的来源.结果表明:PAHs的质量浓度范围为24.705~112.490 ng·m-3,PAHs的质量浓度分布呈现出工业区>交通区>植物园的规律;冬季PAHs质量浓度高于秋季等特征.不同环数PAHs质量浓度呈现出规律变化为:5环>4环>2-3环>6-7环,4环、5环的 PAH 含量比例高表明机动车尾气和煤燃烧排放是主要排放源.不同功能区化合物的比值指示来源略有不同,但总体指明了武汉主要污染源来自燃煤和机动车尾气的排放.源解析结果显示,工业区的污染源主要来自于燃煤,其贡献率为55%,其次为汽油燃烧、柴油燃烧、焦炉和轻质油燃烧.在交通区中,车辆尾气排放(34%)和天然气燃烧(25%)的贡献较大,其次是烹饪、燃煤及木材燃烧.植物园对照区的主要污染源分别是木材燃烧、燃煤、天然气燃烧、车辆排放和烹饪,其中木材燃烧(46%)的贡献最大.     

Vertical distribution and environmental significance of PAHs in soil profiles in Beijing,China

Vertical distribution of both the concentration and composition of polycyclic aromatic hydrocarbons (PAHs) in ten profiles in Beijing has been investigated. The results showed that PAH concentrations and compositions in topsoil from different sampling sites were different. PAH concentrations were much higher in topsoil of the investigated urban area, industrial region, and paddy field with wastewater irrigation than in other areas. Moreover, PAH concentrations in topsoil were much higher than those at greater depth, where the concentrations were relatively consistent in most soil profiles. The fingerprints of PAHs in the samples from topsoil (0–30 cm) in the same profiles were similar and were obviously different from those at greater depth, suggesting that PAH sources were consistent in topsoil samples and were discriminating between topsoil and deeper soils. PAHs in topsoil mainly arose from mixed sources of combustion of liquid fuel, coal, and/or wood, as well as wastewater irrigation, while those at greater depth were derived from soil genesis and the process of soil formation.     

2022年春季南京臭氧污染特征及成因分析

2022年春季,受新一轮新冠疫情影响,长三角各城市采取了一系列管控措施,使得大气污染物排放水平降低。对2022年春季(3—5月)南京及长三角地区的六项污染物尤其是臭氧(O₃)的变化特征进行了分析,从气象因素和O₃前体物方面,同时利用基于观测的模型(OBM)对南京O₃污染变化原因进行了研究,并分析了南京挥发性有机物(VOCs)的关键活性组分和来源。结果表明:2022年春季,南京PM_2.5、PM₁₀、NO₂和CO均值浓度均同比下降,但O₃日最大8 h滑动平均质量浓度(O₃-8 h)同比上升19.8%,O₃-8 h超标时间同比增加9 d;长三角区域O₃-8 h同比上升17.9%,O₃-8 h超标天数为2021年同期的2.5倍。南京O₃浓度上升的原因:一方面是由于不利的气象条件,另一方面是由于南京O₃生成处于VOCs控制区,但氮氧化物(NO_x)降幅大于VOCs降幅,同时结合O₃前体物削减方案的分析结果发现,VOCs和NO_x不当的削减比例会导致O₃浓度不降反升。南京O₃生成的关键VOC活性物种依次为乙醛、丙烯、间/对二甲苯、丙烯醛和乙烯;正定矩阵因子分解(PMF)解析结果显示,机动车尾气是南京城区VOCs的主要来源,其次为液化石油气/天然气使用和石油化工。     

津冀辽地区典型湖库沉积物PAHs污染特征及来源解析

采集津冀辽地区典型3湖库（于桥水库、衡水湖和大伙房水库）表层沉积物样品共29个,利用GC-MS检测了16种多环芳烃含量.结果表明,沉积物中ΣPAHs（ng·g^-1）分别是337.3~1604.1（均值820.0）、461.1~1497.5（均值932.3）和102.3~2240.5（均值564.9）.与国内其他河流湖库相比,3个典型湖库PAHs污染均处于中等水平.3个湖库在环数占比上有着一致性,均以高环数的高占比为主.通过特征比值与主成分分析法进行PAHs源解析,结果表明,3湖库污染主要以燃烧源（包括石油类燃烧、煤及生物质燃烧）为主,少部分为石油源.其中汽油和柴油不完全燃烧污染贡献占比51.4%,煤和薪柴燃烧污染来源贡献为22.3%.风险评价结果显示,于桥水库、衡水湖和大伙房水库表层沉积物中PAHs总体处于中等偏低水平,但对Flu、InP和DahA这3类物质的监控应当加强,做好对应应急措施.     

天津市夏季不同臭氧浓度级别VOCs特征及来源

为深入了解挥发性有机物（VOCs）对臭氧（O₃）污染的影响,基于2019年夏季天津市O₃和VOCs高时间分辨率在线监测数据,对不同O₃浓度级别VOCs污染特征及来源进行分析.结果表明,2019年夏季天津市O₃浓度为优、良、轻度污染和中度污染时,VOCs浓度分别为32.94、38.10、42.41和47.12μg·m^-3.VOCs组分中烷烃、烯烃、炔烃和芳香烃浓度占比分别为61.72%~63.36%、14.96%~15.51%、2.73%~4.13%和18.53%~19.10%,其中烷烃在O₃浓度为良和轻度污染时占比略高,烯烃和炔烃在O₃浓度为优时占比最高,芳香烃在O₃浓度为中度污染时占比最高.浓度较高的VOCs物种主要为丙烷、乙烷、乙烯、甲苯、正丁烷、异戊烷、间/对-二甲苯、丙烯、乙炔、正己烷、异丁烷、苯、正戊烷、异戊二烯和1,2,3-三甲苯,其中异戊烷、正戊烷、苯、乙烯、丙烯、正丁烷和异丁烷浓度贡献随O₃浓度级别上升逐步增加,异戊二烯和1,2,3-三甲苯浓度贡献在轻中度污染时明显升高.烯烃和芳香烃对臭氧生成潜势（OFP）贡献较高,随着O₃浓度级别上升,烯烃对OFP贡献下降,芳香烃贡献上升.乙烯、丙烯、间/对-二甲苯、1,2,3-三甲苯、甲苯、异戊二烯、反-2-丁烯和顺-2-戊烯是影响臭氧生成的关键物种,其中1,2,3-三甲苯、异戊二烯、丙烯和乙烯对OFP的贡献比例在O₃为轻中度污染时明显增加.源解析结果显示,机动车排放源、溶剂使用源、LPG/汽油挥发源、燃烧源、石化工业排放源、天然源和其他工艺过程源是天津市夏季VOCs主要来源,随着O₃浓度级别上升,机动车排放源、LPG/汽油挥发源、石化工业排放源和天然源贡献逐渐增加,燃烧源和其他工艺过程源贡献总体下降,溶剂使用源贡献在轻中度污染时有所下降.