东北地区大气BTEX的时空分布特征

在东北地区7个典型城市中25个监测点进行了观测,时间分别为2008年4月、7月、10月和2009年1月,使用吸附剂采样管采集并通过热脱附-气相色谱-质谱联用技术分析了苯系物样品,系统研究了东北地区大气苯系物的时空分布特征。研究结果表明,苯和甲苯年均浓度值最高,分别为(4.19±2.31)μg/m3和(3.22±1.14)μg/m3,共占苯系物浓度近70%;各功能区按苯系物浓度大小顺序排列为混合区工业区交通区居民区文教区对照区;受排放源和气象条件的影响,采暖期苯系物浓度高于非采暖期苯系物浓度;风向频率影响苯系物浓度分布,沿下风向浓度逐渐降低;苯/甲苯比值分析表明,东北地区苯系物的主要来源是煤燃烧。     

天津市大气中挥发性有机物的组成及分布特点

参照美国EPA TO17的方法研究天津市不同功能区大气中挥发性有机物(VOCs)冬夏季中的组成及浓度水平,共检出62种挥发性有机物,冬季VOCs浓度水平低于夏季;苯系物稳定存在于各功能区且所占比例最高;VOCs的主要来源是机动车尾气。     

沈阳市环境空气中挥发性有机物污染特征及来源解析

基于2019年沈阳市4个不同功能区挥发性有机物(VOCs)小时分辨率的在线监测数据,分析了环境空气中VOCs的污染特征及来源。结果表明,观测期间沈阳市环境空气中VOCs日平均体积分数为(31.5±13.3)×10^-9,4个功能区VOCs体积分数均呈现出冬季明显大于夏季的特征;工业区环境空气中VOCs体积分数明显高于其他功能区。商业交通居民混合区、文化居民混合区、郊区VOCs体积分数呈现明显双峰结构,工业区双峰结构不明显。工业区VOCs以新鲜排放为主,而其他3个区域为老化气团的传输。工业区春、夏季环境空气中VOCs来源包括燃料挥发源(26.90%)、溶剂与涂料源(17.69%)、燃烧源(16.40%)、化工源(15.69%)、交通源(7.57%)和炼油炼焦源(4.15%)。秋、冬季VOCs的来源包括燃烧源(30.77%)、溶剂与涂料源(20.26%)、燃料挥发源(18.79%)、化工源(11.54%)、炼油炼焦源(9.34%)和交通源(5.51%)。     

化工企业废气BTEX排放及周边居民区空气暴露健康风险分析

采用气相色谱-质谱法,于2016年9月和12月对江苏省某化工企业与苯系物排放相关的废气排放口和周边居民区环境空气中苯、甲苯、邻二甲苯、间/对二甲苯、乙苯等5种典型苯系物（BTEX）的排放和区域污染特征进行分析,并开展BTEX来源分析及人体健康风险评估研究。结果表明,化工企业有机废气排放口苯质量浓度最高,超过《化学工业挥发性有机物排放标准》（DB32/3151—2016）限值,超标率达26.4%;环境空气中BTEX平均质量浓度为47.31μg/m³,BTEX检出率均超过80%,秋季和冬季BTEX质量浓度分别为72.5和22.2μg/m³,各组分质量浓度大小排序为：苯＞甲苯＞乙苯＞间/对-二甲苯＞邻-二甲苯,与废气排放口浓度大小顺序一致;与其他城市和地区进行比较,BTEX质量浓度处于中等水平。比值分析法研究BTEX来源结果表明,本地排放源是化工企业周边环境空气BTEX主要来源,一定程度上也受交通排放、化石燃料燃烧等污染源的影响。人体健康风险评估结果表明,BTEX单组分非致癌风险值（HQ）在安全范围之内,各监测点位 BTEX的HQ均＜１,非致癌风险可以忽略不计;苯的致癌风险值（R）为7.33×10^-6～7.49×10^-5,均超过10,有一定的致癌风险,且苯是I类致癌物质,应采取源头控制措施避免健康风险。     

江苏省典型汽车涂装企业VOCs排放特征与污染控制技术

利用物料衡算和源排放测试对江苏省典型汽车涂装企业VOCs排放特征进行研究,并提出最佳治理技术。结果表明,大客车单位涂装面积VOCs排放量达到300 g/m2以上,小轿车为40~60 g/m2。苯系物是VOCs排放的重要组分,最高占比为33.2%~64.6%。乙酸丁酯、异丙醇、丁醇等醇酯类物质近年来广泛用于代替苯系物溶剂,其排放占比为29.6%~61.2%。汽车涂装行业最佳治理技术包括采用3C1B、水性免中涂等先进涂装工艺,用粉末涂料、水性涂料和高固体成分涂料等代替溶剂型涂料,从源头控制排放。采用干式漆雾分离技术、转轮浓缩吸附-蓄热式焚烧技术等先进尾气治理技术,VOCs去除率可达99%以上。     

实验室苯系物测定关键问题的研讨

苯系物是实验室常测项目之一,本文探讨了苯系物测定中影响较大的3个关键问题,避免因溶剂选择不当、校准曲线检测结果偏差大、三点校正浓度选取不正确等原因,影响最后测定结果,为今后实验室苯系物测定提供了一种既简单又准确可靠的方法总结。     

典型污染时段鹤山大气VOCs的臭氧生成潜势及来源解析

2013年10月对广东鹤山大气中挥发性有机化合物（VOCs）变化特征、臭氧生成潜势和来源进行了研究。结果表明,观测期间测得的VOCs总平均值为26.6×10-9,表现为烷烃＞苯系物＞烯烃;烯烃日间值变化幅度较大,在清晨达到最大值;苯系物与一次污染物CO的变化趋势十分接近;烷烃的峰值出现时间较苯系物有所提前,且在短时间内迅速升高,表明观测点周边可能存在排放源;大气中各类VOCs的臭氧生成潜势（OFP）贡献表现为苯系物＞烯烃＞烷烃;从物种来看,乙烯等10种物质对总OFP的贡献占到了80.4%;观测期间测得的OFP贡献较大的VOCs物种主要来源于石化源、油漆溶剂和汽油挥发源。     

上海市交通干道空气中苯系物冬季污染特征初探

2004年冬季对上海市交通干道附近空气中苯系物的浓度水平进行了监测,并采用气相色谱法进行分析。结果表明,采样期间大气中苯、甲苯、乙苯、二甲苯的浓度分别为1.77~27.7μg/m3、7.29~195μg/m3、3.11~40.2μg/m3、4.49~82.4μg/m3。每日6:30~9:30和15:30~19:00两个时段苯系物的浓度要高于中午时间的浓度,与国内其他城市相比,上海市甲苯的浓度要高,浓度水平要远远高于国外城市的测定结果。苯系物的浓度受风速和风向影响较大。提出了制订空气中苯系物的排污清单和加强机动车尾气中苯系物控制的建议。     

西南某化工园区周边区域环境空气中苯系物和卤代烃的污染特征及健康风险研究

于2020年8月和11月,在中国西南某化工园区周边6个采样点采集环境空气样品,对5种典型苯系物(苯、甲苯、乙苯、邻二甲苯、间/对二甲苯)和7种典型卤代烃(三氯甲烷、三氯乙烯、四氯化碳、四氯乙烯、三溴甲烷、一溴二氯甲烷和二溴一氯甲烷)进行研究,明确了区域典型苯系物和卤代烃(BSHs)的污染特征,并评估其对人体的健康风险。结果表明:化工园区周边环境空气中苯系物检出率均 60%,卤代烃中除三溴甲烷、一溴二氯甲烷和二溴一氯甲烷外,检出率均 50%。苯系物和卤代烃的平均质量浓度分别为4.14～11.19μg/m~3和0.30～10.86μg/m~3。BSHs的浓度夏季低于冬季,这可能与人为的季节性燃烧源有关。苯、四氯化碳和四氯乙烯超过国际WELL建筑标准v2,全年超标率分别为3.33%,8.33%和11.67%。BSHs的非致癌和致癌风险均为成人儿童,成人和儿童的非致癌总风险分别为1.87×10~(-2)和1.26×10~(-2),处于可接受水平;成人和儿童的致癌风险分别为1.76×10~(-3)和1.19×10~(-3),处于不可接受水平。     

拉链排咪、塑料制品和印刷行业VOCs排放特征比对分析

采用GC-MS法测定拉链排咪、塑料制品、包装印刷行业的生产车间无组织VOCs排放,得到3个工业源VOCs源成分谱。结果表明：不同工业源排放的VOCs组分存在明显差异,拉链排咪以苯系物为主,占比3529%,主要污染物为正己烷、二氯甲烷、甲苯;塑料制品中苯系物占比为4735%,甲苯、乙酸乙酯、正己烷为主要污染物;包装印刷中苯系物质量分数高达6367%,甲苯、1,2,4-三甲苯、丙酮为主要污染物     

Characterization of Volatile Organic Compounds (VOCs) and Their Sources in the Air of Izmir, Turkey

Air samples were collected in Izmir, Turkey at two (suburban and urban) sites during three sampling programs in 2002 and 2004 to determine the ambient concentrations of several monoaromatic, chlorinated and oxygenated volatile organic compounds (VOCs). Samples were analyzed for 60 VOCs using gas chromatography/mass spectrometry and 28 compounds were detected in most samples. On the average, urban air VOC concentrations were about four times higher than those measured at the suburban site. Toluene (40.6%) was the most abundant compound in suburban site and was followed by benzene (7.4%), o,m-xylene (6.5%), and 1,2-dichloroethane (5.1%). In urban site, toluene (30.5%), p-xylene (14.9%), o,m-xylene (11.4%), and ethyl benzene (7.2%) were the dominating compounds in summer. In winter, toluene (31.1%), benzene (23.9%), 1,2-dichloroethane (9.5%), and o,m-xylene (8.2%) were the most abundant compounds. Receptor modeling (positive matrix factorization) has been performed to estimate the contribution of specific source types to ambient concentrations. Six source factors (gasoline vehicle exhaust, diesel vehicle exhaust+residential heating, paint production/application, degreasing, dry cleaning, and an undefined source) were extracted from the samples collected in the urban site. Three source factors (gasoline vehicle exhaust, diesel vehicle exhaust, and paint production/application) were identified for the suburban site.     

东北地区城市大气颗粒物中多环芳烃的污染特征

2008年4月至2009年1月期间,在东北三省(辽宁、吉林、黑龙江)设立30个观测点位,研究了东北城市大气颗粒物中PAHs的浓度水平、分布及来源.结果表明,不同季节14种PAHs总浓度的变化范围是16.3 ～712.1 ng/m3,呈冬季高、夏季低的季节变化特征;PAHs组成以4～5环化合物为主,3～4环化合物受温度的影响较大,表现出较强的季节波动;8个城市中抚顺和吉林PAHs污染最重,城市不同功能区中以工业区污染较重;燃煤和机动车尾气是区域PAHs的主要来源.     

Pollution characteristics of volatile organic compounds in the atmosphere of Haicang District in Xiamen City, Southeast China

The compositions, spatial distributions, seasonal variations and ozone formation potential (OFP) of volatile organic compounds (VOCs) were investigated in the atmosphere of Haicang District, Xiamen City, Southeast China. Twenty-four types of VOCs were measured in this study, and ethanol, methylene chloride, toluene, ethyl acetate and isopropyl alcohol were the abundant species based on concentration rank. The concentrations of total VOCs (TVOCs) in industrial areas were higher than those in residential and administrative areas and background site. For industrial areas, the TVOCs concentrations in summer were higher than those in winter, which might result from higher emissions from industrial activities because of stronger evaporation in summer. In contrast, non-industrial areas showed higher concentrations in winter due to the unfavorable meteorological conditions. The spatial distribution of BTEX (benzene, toluene, ethylbenzene and xylene) followed the order of industrial areas > residential and administrative areas > background site, and the concentrations in summer were lower than those in winter for most sites. The high ratios (8.9-14.0) of T/B in this study indicated that industrial emissions were the main sources in this district. X/B ratios were used to assess the ages of air parcels and provided evidence of the transport of air parcels among these sites. Total OFP (TOFP) showed the trend of increase with the increase of TVOCs, and toluene was found as the major contributor to TOFP.     

宁波市环境空气中VOCs污染状况及变化趋势分析

基于近7年来的连续监测数据,对宁波市环境空气中挥发性有机物(VOCs)的污染状况及变化趋势进行了初步分析。研究表明:在宁波市环境空气中检测出94种VOCs,其主要成分是饱和烷烃、芳烃、烯烃、卤代烃、卤代芳烃、含氧有机物等,有37种属有毒有害物质,其中苯系物含量最高;宁波市环境空气中苯系物的污染程度与国内外城市基本处于同一水平,近年来的污染状况变化不大,没有明显恶化;空间分布特征显示一类保护区VOCs的排放以天然源为主,二类各功能区VOCs的排放由天然源和局部人为污染源共同形成,三类区以工业污染源排放为主;时间变化趋势显示VOCs在冬季和春季的平均浓度比其他季节高,VOCs的日变化基本呈现2个主浓度峰值特征,跟城市交通流量变化具有很好相关性。     

Personal, indoor, and outdoor exposure to VOCs in the immediate vicinity of a local airport

This study measures the effect of emissions from an airport on the air quality of surrounding neighborhoods. The ambient concentrations of benzene, toluene, ethylbenzene, and o-, m-, and p-xylene (BTEX) were measured using passive samplers at 15 households located close to the airport (indoor, outdoor, and personal), at the end of airport runways and an out-of-neighborhood location. Measurements occurred over a 48-h period during summer 2006 and winter 2006?C2007. The average concentrations were 0.84, 3.21, 0.30, 0.99, and 0.34 ??g/m³ at the airport runways and 0.84, 3.76, 0.39, 1.22, and 0.39 ??g/m³ in the neighborhood for benzene, toluene, ethylbenzene, m-, p-, and o-xylene. The average neighborhood concentrations were not significantly different to those measured at the airport runways and were higher than the out-of-neighborhood location (0.48, 1.09, 0.15, 0.78, and 0.43 ??g/m³, each BTEX). B/T ratios were used as a tracer for emission sources and the average B/T ratio at the airport and outdoors were 0.20 and 0.23 for the summer and 0.40 and 0.42 for the winter, suggesting that both areas are affected by the same emission source. Personal exposure was closely related to levels in the indoor environment where subjects spent most of their time. Indoor/outdoor (I/O) ratios for BTEX ranged from 1.13 to 2.60 and 1.41 to 3.02 for summer and winter. The seasonal differences in I/O ratios reflected residential ventilation patterns, resulting in increased indoor concentrations of volatile organic compounds during winter.     

Seasonal variation of polycyclic aromatic hydrocarbons in soil and air of Dalian areas, China: an assessment of soil-air exchange

The seasonal variations of concentrations of PAHs in the soil and the air were measured in urban and rural region of Dalian, China in 2007. In soil, mean concentrations of all PAHs in summer were larger than those in winter, whereas the concentrations of heavier weight PAHs in winter were larger than those in summer. Winter/summer concentration ratios for individual PAHs (R(W/S)) increased with the increase of molecular weight of PAHs in soil, indicating that PAHs with high molecular weight were more easily deposited to soil in winter than summer. In air, mean concentrations of all PAHs in winter were larger than those in summer. In comparison with the R(W/S) in soil, all the values of R(W/S) in air were larger than one indicating that the entire individual PAH concentrations in winter were larger than those in summer. The average concentration composition for each PAH compound in soil and air samples was determined and the seasonal change of PAH profile was very small. It was suggested that PAHs in soils and air had the same or similar sources both in winter and summer. The approach to the soil-air equilibrium was assessed by calculating fugacity quotients between soil and air using the soil and air concentrations. The calculated soil-air fugacity quotients indicated that soil acted as a secondary source to the atmosphere for all lighter weight PAHs (two-three rings) and it will continue to be a sink for heavier weight PAHs (five-six rings) in the Dalian environment, both in winter and summer. Medium weight PAHs (four-five rings) were close to the soil-air equilibrium and the tendency shifted between soil and air when season or function region changed. The fugacity quotients of PAHs in summer (mean temperature 298 K) were larger than those in winter (mean temperature 273 K), indicating a higher tendency in summer than winter for PAHs to move from soil to air. The variation of ambient conditions such as temperature, rainfall, etc. can influence the movement of PAHs between soil and air. Most of the fugacity quotients of PAHs for the urban sites were larger than that for the rural site both in winter and summer. This phenomenon may be related with that the temperatures in urban sites were higher than those in the rural site because of the urban heat island effect.     

Long-term phenol, cresols and BTEX monitoring in urban air

This paper reports the results of a long-term monitoring of benzene, toluene, ethylbenzene, xylenes (BTEX), phenol and cresols in the air of Padua during a wide period of the year 2007 using two radial passive samplers (Radiello system) equipped with BTEX- and phenol-specific cartridges. Two sites were monitored, one in the industrial area and one close to the town centre. Relevant pollution episodes have been observed during both the winter and summer periods. Benzene, together with toluene, ethylbenzene and xylenes showed their maximum concentrations during the winter season, but the secondary pollutant phenol was higher than benzene for a large period of the year when the meteorological conditions blocked the pollutants in the lower layers of the atmosphere and solar radiation increased the benzene photo-oxidation process.     

Seasonal variations in nickel and vanadium in Mont Blanc snow and ice dated from the 1960s and 1990s

Ni and V have been determined in snow and ice collected at a high altitude location (Col du D?me) near the summit of Mont Blanc on the French-Italian border; dated from the 1960s and 1990s. Ni and V were simultaneously determined by inductively coupled plasma sector field mass spectrometry. Measured concentrations range from 6 to 700 pg g(-1) and 4 to 1,100 pg g(-1) for Ni and V, respectively. The results show pronounced seasonal variations in the concentrations of both metals, with high concentration values in summer layers and much lower values for winter layers. These seasonal variations are linked especially with the existence of inversion layers during winter months. Ni and V concentrations in excess of the contributions from rock and soil dust (Ni(excess), V(excess)) appear to be mainly associated with anthropogenic inputs, with pronounced seasonal variations. Large variations in the V(excess)/Ni(excess) ratio are observed, with a higher ratio in summer than in winter. This shows differences in anthropogenic inputs at Col du D?me during the different parts of the year. The above ratio was compared with the corresponding ratios for oil combustion from stationary sources and the exhaust from gasoline and diesel engines. It appears that Ni and V concentrations at Col du D?me are probably the result of changing combinations of contributions from oil combustion for power generation, industrial and residential uses, on one side, and automobile and truck traffic, on the other side, with possibly a significant contribution from Ni smelters in Russia during winter months.     

在线分析宁波市北仑区VOCs组成、趋势及来源

利用VOCs在线监测技术,对2010年宁波市北仑区空气内的VOCs的浓度、组成、变化规律及来源进行分析研究。结果表明,在北仑区域内的16种VOCs中,苯、甲苯、二甲苯、乙苯和己烷的比例占到了总数的82．9％,且该5种有机物浓度存在较为典型的季节性变化规律和日变化规律;采用CMD模型法对VOCs的来源进行解析后发现,北仑区域内的VOCs主要来源于汽车尾气、汽油蒸气和石油液化气,而且汽车尾气的贡献值要比一些大城市低得多,且夏季和冬季的成分源贡献率存在明显差异。     

天津市臭氧污染特征与影响因素分析

2013—2015年,天津市臭氧(O_3)浓度整体呈下降趋势,污染状况略低于京津冀区域的其他城市。O_3浓度春、夏季高,冬季低,高值主要集中在5—9月,浓度从早上06:00开始升高,至中午14:00达到峰值。污染主要集中在中心城区、西部和北部地区,东部、南部和西南部地区污染相对较轻。O_3浓度在温度303 K以上、相对湿度70%以下或西南风为主导时较高。VOCs/NOx比值低于8,O_3的生成处于VOCs控制区。芳香烃类和烯烃类对天津市O_3生成贡献最大,其中,乙烯和甲苯为O_3生成潜势贡献最大的物种,其次为间/对二甲苯、丙烯、邻二甲苯、异戊二烯、反-2-丁烯、乙苯等,通过控制汽车尾气、化工行业及溶剂使用等对O_3生成潜势贡献大的VOCs排放源可有效控制天津市O_3污染。