城市居住空气中苯系物的测定来源分析

本文讨论了城市居住警察擗苯，甲苯，二甲苯的采集，测量和来源的识别方法，分别在受污染居住区和未受污染居住区，用活性炭吸收，气相色谱法测定苯系物，通过日烨地比方法玫各种苯系物之间浓度相关性的观察，判断居住区苯系物的来源，为环境管理和污染防治提供科学依据。     

北京市大气挥发性有机物(VOCs)的污染特征及来源

挥发性有机物(VOCs)的排放是大气污染的重要来源,已经成为我国最重要的环境问题之一,北京市的污染尤为严重。本文对北京市近年来大气挥发性有机物、苯系物的污染情况和来源以及不同控制措施下挥发性有机物的浓度变化进行了总结概括,并对今后的研究进行了展望。     

中国北方典型城市空气中苯系物的污染特征

为了研究中国北方典型城市大气中苯系物的污染状况和季节变化特征,于2008年4月—2009年1月间,选取沈阳和天津共11个监测点位分别采集大气样品,并利用三级冷阱预浓缩-GC-MS方法进行分析.结果表明,天津的苯系物污染浓度比沈阳高,这是因为天津的机动车保有量远远大于沈阳,机动车尾气排放量大.苯系物的污染程度与不同季节的气候变化密切关联,两城市均表现为春秋两季污染严重,冬夏两季污染较轻.城市不同功能区采样点的比较和苯与甲苯(B/T)的比值以及各苯系物之间的相关性分析表明,两城市苯系物污染浓度均受到局部排放源的明显影响,但在大部分地区交通源仍为主要排放源.     

北京市典型城区环境空气中苯系物的污染特征、来源分析与健康风险评价

自2013年6月以来,利用Airmo VOC在线分析仪在北京市典型城区开展了环境空气中挥发性有机物(VOCs)的连续观测,选取2014年4个季节中各1个月的苯系物在线数据,分析了其浓度水平、变化特征、光化学反应活性,利用美国环保署(US EPA)提出的健康风险评价方法开展了有毒有害苯系物物种的健康风险评价,结合来源分析结果,明确北京市应重点控制的苯系物污染来源。研究区观测期间环境空气中16种苯系物的质量浓度为(22.64±16.83)μg·m-3,且具有秋季冬季春季夏季的特点,其中BTEX(苯、甲苯、乙苯和二甲苯)的质量浓度为(19.27±14.46)μg·m-3,占苯系物浓度水平的41.09%~95.16%。研究区观测期间苯系物质量浓度夜间高于日间,日变化呈V字形,在13:00—15:00时质量浓度低。16种苯系物的臭氧生成潜势(OFP)的范围为66.62~170.67μg·m-3,其中间+对二甲苯、甲苯和邻二甲苯的OFP值相对较大;二次有机气溶胶生成潜势(SOAFP)的范围为0.71~1.86μg·m-3,其中甲苯、间+对二甲苯和乙苯的SOAFP值相对较大。研究区观测期间6种苯系物(BTEX和苯乙烯)的危害指数在8.19E-03~5.01E-02之间,在4个季节中对暴露人群尚不存在非致癌性风险;而Ⅰ类致癌物质苯的风险值处于7.13E-08~8.13E-06之间,在夏、秋和冬季对研究区暴露人群的人体健康均存在潜在的致癌性风险。来源分析结果表明,研究区春、秋季苯系物主要来源于机动车尾气的排放,其中春季还受到溶剂等挥发的影响,夏、冬季苯系物则主要来自于燃煤源。     

北京市典型城区环境空气中苯系物的污染特征、人体健康风险评价与来源分析

自2013年6月以来利用Airmo VOC在线分析仪在北京市典型城区开展了环境空气中挥发性有机物(VOCs)的连续观测,选取2014年4个季节中各1个月的苯系物在线数据,分析了其浓度水平、变化特征、光化学反应活性,利用美国环保署(US EPA)提出的人体健康风险评价方法开展了有毒有害苯系物物种的人体健康风险评价,结合来源分析结果,明确北京市应重点控制的苯系物污染来源。研究区观测期间环境空气中16种苯系物的质量浓度为22.64±16.83μg·m-3,且具有秋季冬季春季夏季的特点,其中BTEX(苯、甲苯、乙苯和二甲苯)的质量浓度为19.27±14.46μg·m-3,占苯系物浓度水平的41.09%~95.16%。研究区观测期间苯系物质量浓度夜间高于日间,日变化呈V字形,在13:00~15:00时质量浓度低。16种苯系物的臭氧生成潜势(OFP)的范围为66.62~170.67μg·m-3,其中间+对二甲苯、甲苯和邻二甲苯的OFP值相对较大;二次有机气溶胶生成潜势(SOAFP)的范围为0.71~1.86μg·m-3,其中甲苯、间+对二甲苯和乙苯的SOAFP值相对较大。研究区观测期间6种苯系物(BTEX和苯乙烯)的危害指数在8.19E-03~5.01E-02之间,在四个季节中对暴露人群尚不存在非致癌性风险;而Ⅰ类致癌物质苯的风险值处于7.13E-08~8.13E-06之间,在夏、秋和冬季对研究区暴露人群的人体健康均存在潜在的致癌性风险。来源分析结果表明,研究区春、秋季苯系物主要来源于机动车尾气的排放,其中春季还受到溶剂等挥发的影响,夏、冬季苯系物则主要来自于燃煤源。     

南京市典型交通区与背景区春季大气中VOCs的污染水平与日变化趋势

于2014年春季使用Tedlar气袋采集南京市典型交通区与背景区的大气样品,参照美国EPA TO-15方法共检出30种挥发性有机物(VOCs)组分,研究了典型区域的VOCs污染特征与日变化趋势。结果表明,交通区ρ(VOCs)范围为122.58!236.97μg·m-3,平均值为(149.31±36.70)μg·m-3;背景区ρ(VOCs)范围为27.24!54.68μg·m-3,平均值为(43.29±10.53)μg·m-3。从污染物类型来看,烯烃、芳烃、卤代烃和酯类化合物是空气中的主要污染物。交通区空气中VOCs以苯系物为主,质量浓度范围为18.72!41.28μg·m-3,平均值为(25.39±7.63)μg·m-3,苯系物浓度日变化高峰出现在9:00、12:00和18:00,与道路车流量密切相关;而背景区苯系物浓度偏低,且无明显的变化趋势。对交通区苯系物各组分进行主成分分析发现,苯、乙苯、对,间-二甲苯、邻-二甲苯、4-乙基甲苯、1,3,5-三甲苯和1,2,4-三甲苯是主要的贡献因子,汽车尾气是交通区苯系物污染的主要来源。     

北京市东北城区夏季环境空气中苯系物的污染特征与健康风险评价

于2013年8月2日至31日,利用Airmo VOC在线分析仪开展了北京市东北城区环境空气中挥发性有机物(VOCs)的在线监测,分析了其中16种苯系物的污染水平、变化特征、来源及其臭氧形成潜势(OFP),并采用US EPA的健康风险评价模型对BTEX(苯、甲苯、乙苯、间-对二甲苯、邻二甲苯)和苯乙烯的人体健康风险进行了评价。结果表明,16种苯系物在观测期间总平均质量浓度为10.36μg·m-3,其中BTEX的质量浓度均值为7.45μg·m-3,约占总的苯系物质量浓度的72%。苯系物的质量浓度呈现明显的一次污染物日变化特征,即早晚较高,中午较低。苯与甲苯的质量浓度比值(B/T)平均为0.39,说明除机动车尾气外,涂料和溶剂的挥发释放对大气中苯系物也可能具有重要贡献。间-对二甲苯、1,2,4-三甲苯和甲苯的OFP值较高,对北京市大气臭氧光化学形成具有显著贡献。BTEX和苯乙烯对人体的非致癌风险危害商值在8.70E-05至3.76E-02之间,危害指数为6.19E-02,对暴露人群尚不存在明显的非致癌风险;而苯的致癌风险值为8.80E-06,超过了US EPA的建议值1.00E-06,显示苯对研究区居民身体健康存在潜在的致癌风险。     

固相微萃取采集空气中苯系物的竞争吸附效应

通过采用多组分苯系物标准气体对萃取头的吸附情况进行分析和各种参数的考察,对固相微萃取技术应用于空气中苯系物的检测方法和相互的竞争吸附行为进行了研究,结果表明,固相微萃取技术在空气中苯系物定量检测的应用过程中受多种因素影响,各种苯系物在萃取头表面存在显著的竞争吸附效应使定量较为困难,但通过标准加入法可满足定量检测的需要,并得到了相应的应用条件和范围.     

2009年北京市苯系物污染水平和变化特征

采用Tenax-TA/吸附热解吸、光离子化气相色谱法(GC-PID)对北京市大气中苯系物(BTEX)的小时平均浓度进行了为期1年的观测.结果表明,苯、甲苯、乙苯、间/对-二甲苯和邻二甲苯的年平均浓度分别为:4.43、7.03、2.27、4.18和2.06μg.m-3.苯系物之间具有很好的同源性,其浓度存在明显的日变化和季节变化,这些变化特征与交通尾气排放、采暖期化石燃料燃烧、光化学反应活性等密切相关.苯与甲苯特征比值(B/T)的分析表明,交通尾气排放是北京市大气中苯系物的主要来源,冬季和早春采暖期化石燃料燃烧也是北京市大气中BTEX的重要来源之一.乙苯与二甲苯比值(E/X)的季节变化为:夏季>春季>秋季>冬季,与北京市大气光化学反应活性季节变化趋势相似.2009年北京夏季总苯系物的平均浓度比2004年夏季减少了2/3,表明北京市政府为改善空气质量所采取的一系列控制措施十分有效.     

环境参数对硝基清漆苯系物散发的影响

本文利用环境测试舱法对硝基清漆中苯系物的释放特征及影响因素进行了研究,在不同温度、相对湿度和空气流速下测试苯系物释放,并采用一阶衰减模型进行模拟.结果表明,苯系物的初始释放速率和衰减速率均与温度和空气流速呈线性正相关关系,而相对湿度并不影响苯系物的初始释放速率和衰减速率;温度和空气流速在释放初始阶段对释放的影响较大,随着苯系物的不断挥发,其影响逐渐变小,因此,增加温度和空气流速有助于加速苯系物的释放,缩短苯系物的释放周期,达到控制苯系物浓度的目的.     

Planning for the monitoring of pollutants from non‐stationary combustion sources†

The most important constituents of traffic exhaust are carbon monoxide, nitrogen oxides, volatile organic compounds, polycyclic hydrocarbons and lead. Satisfactory analytical methods are available for measuring these compounds, but the required expenditure in their application to air pollution studies is quite different. Due to correlations between the concentrations of several exhaust components in road air conclusions regarding the expected level of some substances can be drawn by measurement of another emitted compound. But the selection of indicator compounds must be made under the aspect of the source‐specific relationship of emitted substances. The temporal and spatial distribution of air pollutants in street air is affected by traffic emissions more than by meteorological conditions. “Fingerprints”; of typical organic gaseous components of traffic exhaust also were found in residential areas.     

室内空气中多环芳烃污染的测量和特征性研究

本文就室内空气中多环芳烃典型污染源－室内燃煤和室内吸烟排放的多环芳烃组成和含量进行了测定，并同室外大气（对照）中多环芳烃组成含量进行了对比，研究了室内环境不同污染源排放多环烃组成和含量的特征性，结果表明，室内燃煤污染同燃煤型室外大气源排放多环芳烃具有相似组成含量特征，而室朵烟草烟雾污染源的多环芳烃组成含量特征，则与室外煤型和交通型均有显著区别。     

Source apportionment of polycyclic aromatic hydrocarbons in Lake Baikal water and adjacent air layer

The composition of polycyclic aromatic hydrocarbons (PAHs) in Lake Baikal water and adjacent air layer and PAH emission composition profiles of possible sources were investigated. Analysis of emission composition data showed that the source profiles could not be grouped by fuel type or pyrogenic/petrogenic origin. Because of the similarity of source PAH profiles, the drawing of 3D mixing diagrams was the only way to check whether some of the potential PAH sources were the true sources. The mixing diagrams showed that the sources of air pollution were paper mills and wood burning and that the sources of water pollution were coal-fired and oil-fired boilers. The common source for both air and water was only oil and petroleum products. To determine the locations of PAH sources, their contributions to air and water pollution were calculated and mapped. Based on the results, air and water were polluted from both local and regional sources. The location of the zone influenced by a particular source was conditioned by physical properties of source emission, direction of air/water flows that transfer PAHs and temperature differences between mixing air/water flows.     

长江三角洲河网地区典型城镇街尘中多环芳烃的污染特征

街尘是一种重要的环境介质,其携带的污染物在城镇化过程中对河网地区的水环境构成了一定的威胁.为初步探讨长江三角洲河网地区典型街尘中多环芳烃(PAHs)的污染特征,以杭嘉湖平原河网地区饮用水水源河流上游典型小城镇的街尘为研究对象,对工业区、交通干道、旧居区、新居区和商业区5种土地利用类型的15个采样点进行街尘样品采集和粒径分级,测试街尘的密度、有机质含量以及16种U.S.EPA优控PAHs含量等指标.结果表明,粒径为<63、63～125、125～250和250～900μm街尘中总多环芳烃(∑PAHs)的平均含量分别为7261、5835、4660和2909μg·kg-1,粒径越小,PAHs含量越高,其生态风险越大.不同土地利用类型的街尘中PAHs的含量顺序依次为:工业区>交通干道>旧居区>新居区>商业区.街尘中PAHs和有机质含量存在显著正相关关系,且街尘粒径越小,有机质和PAHs的相关性越强.源解析结果表明,街尘中的PAHs多为燃烧源.     

An interval dynamic multimedia fugacity (IDMF) model for environmental fate of PAHs and their source apportionment in a typical oilfield,China

An interval dynamic multimedia fugacity (IDMF) model with a new validation criterion of interval average logarithmic residual error (IALRE) was developed in this study. The environmental fate of polycyclic aromatic hydrocarbons (PAHs) and their source apportionment in a typical oilfield of China were simulated from 1985 to 2010. The PAH concentrations predicted by the model were in agreement with the measured concentrations, which were indicated by the IALREs calculated at 0.41, 0.63, 0.52, and 0.58 for air, water, soil, and sediment, respectively. The multimedia concentrations of Σ16 PAHs were 29.55, 39.22, 31.98, and 26.69 times greater in 2010 than those in 1985, and were higher than any other year modelled. Additionally, 87.82% of PAHs remained in the soil in 2010. PAH source emission into the soil was the major modelled source, whereas PAH degradation in the air was the major modelled loss pathway; the dominant transfer process between the adjacent compartments was atmospheric deposition from air to soil. It was demonstrated that high-temperature combustion was the major source of PAHs in the air and soil, whereas biomass and coal combustion were attributed to water and sediment compartments. The IDMF model was effective in the dynamic source apportionment of PAHs.     

南京市大气中挥发性有机物污染的研究

1　IntroductionVolatileorganiccompounds (VOCs)areimportantairpollutantsintheurbanatmosphere .SomeVOCsaretoxicandpotentiallycarcinogenic.ExposuretoVOCsisofconcernasitmayresultinsignificantrisktohumanhealth .AmbientVOCsareemittedfromvariousurban ,industrial…     

苯系化合物好氧生物降解性研究

选用城市污水处理场的活性污泥做菌源，研究了苯、甲苯、邻－间－、对－二甲苯、乙基苯、三甲苯等七种芳香化合物的好氧生物降解规律。实验结果表明，七种化合物浓度在１０ｍｇ／ｌ左右时，在实验周期内能全部降解；浓度在４０－１８０ｍｇ／ｌ时，有的化合物不能被降解。七种化合物降解的难易程度为：甲苯＞间二甲苯＞苯＞对二甲苯＞乙基苯＞三甲苯＞邻二甲苯。此外，实验结果还表明，化合物的降解性受苯环上取代基数量及位置等因素     

石家庄市室内空气中甲醛、苯系物和TVOC的污染特征

在石家庄市内选取部分新装修装饰的民用住宅进行室内空气采样,对甲醛、苯、甲苯、二甲苯和TVOC分别采用酚试剂分光光度法和气相色谱法进行分析。测定结果表明:新装修装饰后的室内空气中甲醛、苯、甲苯、二甲苯和TVOC存在不同程度的超标现象,其中,甲苯污染相当严重,最大超标倍数为17.7;卧室中甲醛、苯、甲苯、二甲苯和TVOC等污染物的超标率普遍高于客厅,其中卧室甲醛超标率约为客厅的2倍;室内空气中甲醛浓度随着密闭时间的增加持续增加。最后提出一系列相应的防治措施与建议。     

Influence of simulated tidal cycles on aromatic hydrocarbon uptake and elimination by the shore crab Hemigrapsus nudus

Specimens of the intertidal crab Hemigrapsus nudus (Dana, 1851) were collected near Sitka, Alaska, in 1983, and were used in laboratory experiments to determine the influence of periodic exposure to air on the toxicity, uptake, and elimination of two aromatic hydrocarbons, toluene and naphthalene. Three tidal cycles were simulated; i.e., crabs spent 0, 33, or 66% of the time in air and the remainder of the time in toxicant or seawater solutions. Naphthalene was 10 to 20 times more toxic than toluene: naphthalene caused locomotory impairment or killed the crabs more rapidly and at concentrations lower than those of toluene. In tissues, naphthalene was accumulated faster and to higher concentrations than was toluene. Exposure to air 66% of the time reduced mortality as well as the rate at which toluene and naphthalene were accumulated and lost. Crabs exposed to air had significantly higher respiration rates than those submerged in seawater; thus, reduced rates of accumulation and loss of hydrocarbons were not caused by general metabolic quiescence. Exposure to air reduced the time the crabs were in contact with water-borne hydrocarbons and, therefore, reduced toxicity of the hydrocarbons. Once crabs had accumulated the toxicants, however, elimination was hindered by exposure to air, even for the somewhat volatile compound toluene.