我国城市住宅室内空气挥发性有机物污染特征

通过调研1990年以来我国城市住宅室内空气污染的研究资料,提炼城市住宅室内空气中挥发性有机物的浓度数据,总结甲醛、苯系物等常见住宅室内挥发性有机物的污染水平和分布规律,并且对主要由装修引起的污染物浓度与装修时间的关系进行了探讨. 分析发现,我国城市居民住宅室内普遍呈现以甲醛、苯、二甲苯等污染物为主的装修型污染,甲醛是首要污染物,ρ(甲醛)平均值为0.05～0.61 mg/m3,ρ(苯)、ρ(甲苯)、ρ(二甲苯)、ρ(乙苯)和ρ(TVOC)平均值分别为0.001~0.134、0.003~0.645、0.001~1.012、0.001~0.091和0.11~1.81 mg/m3. 新装修住宅室内空气中各种污染物均呈现较高的浓度水平,除甲醛外,其他挥发性有机物随着竣工时间的推移而快速下降.      

热传导强化气相抽提处理苯系物污染土壤实验

以苯系物(BTEX)污染土壤为研究对象,研究加热源功率和加热时间对土壤苯系物去除率的影响;实验通过分析尾气和冷凝水的污染物浓度来判断实验的终止时间点.结果显示,在3个功率100、200 W和400 W作用下,各污染物的残留浓度较低,所需要的处理时间分别为168.5、122.5 h以及104 h,消耗的总电能分别为:0.49、0.56 KW.h.Kg-1TS以及0.81 kW.h.Kg-1TS.功率越高,土壤中BTEX去除效率越高,同时能耗也越大.实验通过分析处理前后土壤中有机质含量,发现在加热的条件下有机质会逐渐减少,功率越高,有机质去除的速率越快,越有利于污染物的去除.本文的结果可证实通过加热可有效提高土壤中苯系物的气相抽提去除效率,对现场中试的开展提供参数依据.     

Spatial and seasonal variations of atmospheric BTEX,sulfur dioxide,nitrogen dioxide,and ozone concentrations in Istanbul,and health risk assessment of BTEX

Volatile organic compounds (VOCs) such as benzene, toluene, ethylbenzene, and xylene (BTEX) along with inorganic gases such as sulfur dioxide (SO₂), nitrogen dioxide (NO₂), and ozone (O₃) levels were found in the atmosphere of the Kemerburgaz region where environmental issues became a major concern due to nearby incineration plant and waste disposal facility in Istanbul. Ten sampling locations were selected considering possible sources in the study area. The sampling areas were classified as suburban, industrial, rural, and background regions. Sampling campaigns were carried out for four-week periods from March 2011 to August 2012 in all locations. Elevated concentrations of BTEX around roads and the industrial locations indicated that vehicle exhaust and industrial activities were the main sources of these pollutants in the region. Concentrations of NO₂ were also high around roads. A much more uniform distribution was observed for SO₂ during sampling periods. However higher levels were observed at suburban locations due to the use of coal for local heating especially during winter. Ozone concentrations were low at the industrial locations and roadsides, but high in suburban and rural locations downwind from the sources. The results of these organic and inorganic gases meet the national limit values. Furthermore, a lifetime risk assessment methodology was used to evaluate the potential adverse health effects of BTEX. The mean cancer risk level for benzene was estimated to be 7.71E-07 that is lower than assigned acceptable risk level of 1.0E-04. Toluene, ethylbenzene, and xylenes were lower than the specified level of 1.0 with respect to mean non-carcinogenic risks. The findings reveal that determined BTEX emissions do not pose a health threat to residents in the studied region.     

室内空气中苯系物污染现状及治理措施

苯系物指苯及苯的同系物,室内空气中的苯系物主要包括苯、甲苯和二甲苯。本文介绍了室内空气中苯系物的来源以及对人体的危害作用,讨论了目前室内苯系物的治理措施,为苯系物的治理提供一定的理论依据。     

顶空-气相色谱法测定水中苯系物的不确定度研究

建立顶空-气相色谱法测定水中苯系物不确定度的评定方法,分析测定过程中的主要影响因素,评定测定过程中引入不确定度的来源.通过分析和量化影响测定结果的不确定度分量,得出各分量对不确定度的相对贡献,对测定结果进行了表述.结果表明,顶空-气相色谱法测定水中苯系物七种组分的相对合成不确定度范围为6.09％ ∽ 11.11％,苯乙烯和邻二甲苯的不确定度较大,不确定度的主要影响因素为标准溶液及曲线配制、方法加标回收和样品重复测量.     

生物滴滤池对BTEX的去除及相应细菌群落分析

以预先驯化的菌群和活性污泥作为起始接种物用于生物滴滤池(BTF)中,研究评估了BTF去除苯、甲苯、乙苯和二甲苯混合气体(BTEX)的性能,并利用变性梯度凝胶电泳(DGGE)技术分析了微生物群落结构的变化.结果表明,BTF能在短时间内得到驯化,填料附着的生物量从第10 d的5.7 mg.g-1迅速增加至第30 d的112 mg.g-1.BTF能同时有效去除混合BTEX中的各组分,在进气负荷和停留时间分别为269.7 g.(m3.h)-1和39 s时,可获得的最大去除能力为216.6 g.(m3.h)-1.DGGE图谱表明,BTF中优势微生物种群主要来源于富集菌群,微生物群落结构随着运行时间发生变化,但在BTF上下空间分布较为均匀.     

Sources of Volatile Organic Compounds in a University Building

A total of 34 volatile organic compounds (VOCs) were measured in the indoor of laboratories, offices and classrooms of the Chemical Engineering Department of Hacettepe University in Ankara in 2 week-day passive sampling campaigns. The average concentrations ranged from 0.77 to 265 μg m^?3 at the different indoor sites, with the most abundant VOC found to be toluene (119.6 μg m^?3), followed by styrene (21.24 μg m^?3), 2-ethyltoluene (17.11 μg m^?3), n-hexane (10.21 μg m^?3) and benzene (9.42 μg m^?3). According to the factor analysis, the evaporation of solvents used in the laboratories was found to be the dominant source.     

新型动态针捕集阱技术分析大气中低浓度的VOCs

本研究针对大气中挥发性有机物（VOCs）浓度低,难于分析等特点,以Carboxen 1000作为吸附剂,制作一种新型动态针捕集阱（needle trap）装置,可用于主动富集大气中低浓度VOCs.该装置与气相色谱-质谱（GC-MS）联用,操作简单、无需溶剂、容易定性定量.选择空气中苯系物（BTEX）为目标化合物,对needle trap装置从设计原理到实际应用进行了详细分析,将萃取条件与穿透体积等实验条件进行优化,建立了needle trap吸附提取空气中BTEX的最佳条件.结果表明,方法检出限低至0.05ng·mL-1,加标回收率为86.5%～110.5%,符合外场采样要求.     

北京市BTEX的污染现状及变化规律分析

2008年10～2009年10月,利用前级浓缩-气相色谱/质谱法,对北京市大气中5种苯系物BTEX（苯、甲苯、乙苯、间、对二甲苯、邻二甲苯）的组成及浓度变化进行了采样分析研究.结果表明,北京市大气BTEX平均浓度为13.9～44.0μg.cm-3,其中甲苯的含量最高,苯次之,邻二甲苯含量最低,与国外城市和地区相比北京大气中BTEX浓度较低,研究发现北京市BTEX主要来自机动车排放,城市燃煤和工业溶剂挥发也是BTEX的重要来源.一年的观测结果表明,BTEX春、夏季节浓度较高,秋季浓度较低,季节性排放源的变化是BTEX季节变化的主要原因,同时也不能忽视温度和大风等天气因素对BTEX浓度的影响.受交通排放和边界层高度的影响,BTEX类化合物的日变化形式为夜晚高于白天,呈双峰形,日最低浓度出现在14：00前后.     

不同化学氧化剂对焦化污染场地苯系物的修复效果

采用自制全封闭模拟装置比较研究了Fenton试剂、类Fenton试剂、高锰酸钾以及活化过硫酸钠4种常用的化学氧化剂对焦化工业污染场地中苯系物的去除效果.结果表明,去除土壤BTEX效果较好的是Fenton试剂和类Fenton试剂,在最佳剂量条件下分别能使BTEX的浓度降低83%和73%,且反应过程中经挥发进入到回收液中的...