炼焦粉尘中多环芳烃的赋存特性

通过对焦化厂不同地点的粉尘采样,并进行粒度分级、超声波预处理及高效液相色谱分析,得到多环芳烃（PAHs）的赋存特性。在采集的样品中,地面除尘站粉尘仓的粉尘中PAHs的含量最高,达到1880．83μg／g。在焦化粉尘中,PAHs明显表现出对小粒径粉尘的富集特性,粉尘中单组分的PAHs含量差别较大,以4～6环的PAHs居多。此外,地面除尘站粉尘仓的粉尘样品中含有大量的苯并[a]芘。     

大气中多环芳烃的分布特征研究进展

大气中PAHs的分布特征主要表现为时空分布不同。不同的地区间浓度不同,重工业城市大气中PAHs浓度明显高于轻工业城市,近年来我国大气环境质量明显好转,地区间PAHs污染浓度差异缩小;不同环数PAHs在气固两相以及在不同粒径颗粒物中分布不同,低环数PAHs主要分布在气相中和大粒径的颗粒物中,高环数PAHs主要分布于固相中和小粒径的颗粒物中;不同季节大气中PAHs的浓度不同,北方地区采暖期高于非采暖期,南方地区冬季气态PAHs浓度夏季高于冬季,颗粒物中PAHs浓度冬季>秋季>春季>夏季;室内PAHs浓度高于室外,不同场所空气中PAHs浓度不同。     

韩家湾煤及其热解半焦中多环芳烃分布特征研究

低阶煤的热解是其深加工工艺的基础,为探究其固体产物半焦中多环芳烃(PAHs)的含量水平及组成特征,以陕西榆林韩家湾次烟煤及其不同温度条件下(350℃～700℃)生成的热解半焦为样品,采用溶剂萃取结合GC/MS方法分析其中PAHs分布特征。结果显示：韩家湾原煤中16种优控母体(美国环保署规定)PAHs含量(∑16PAHs, 15 161 ng/g)低于对应烷基取代PAHs含量(∑aPAHs, 24 055 ng/g),380℃热解半焦中∑16PAHs(19 003 ng/g)和∑aPAHs(45 009 ng/g)均呈极大值;半焦中∑16PAHs和∑aPAHs随温度呈先增后降的变化趋势,但aPAHs含量随热解温度变化的幅度大于16PAHs含量变化的幅度,推测热解过程释放的PAHs可能以aPAHs为主;16PAHs组成上,原煤以4环母体PAHs为主,半焦中则以2～3环PAHs为主;350℃～400℃热解半焦中萘和烷基萘含量显著高于原煤中相应成分的含量,表明煤在低温热解时发生裂解反应并生成大量萘系物。     

不同煤种热解多环芳烃的生成分布特征研究

研究了四种适宜地下气化的低阶煤在600℃热解条件下热解气中EPA-PAHs的生成分布特征,探讨了原煤组成的影响.结果表明,随着煤变质程度的增大,热解所产生的低环芳烃含量减少,高环芳烃含量增加,EPA-PAHs总量增加;热解气中EPA-PAHs以2R萘、3R苊、3R二氢苊、4R荧蒽、4R芘和4R苯并(a)蒽为主;3R芳烃含量最多,平均占EPA-PAHs总含量的67.57%;EPA-PAHs含量分别在碳含量为76.98%,H/C摩尔比为0.94,O/C摩尔比为0.16和挥发分为43.32%时达到最高水平.     

大气颗粒物中多环芳烃的粒径分布

用GC/MS法测定了北京市北部的城乡结合部和远郊区的大气颗粒物中的16种优控多环芳烃(PAHs)的浓度。采样时间从2003年1月到11月,分季节采样。采样器采集的大气颗粒物粒径分为5段,粒径范围从小于等于1.1μm到100μm。对颗粒物中的总优控PAHs和检测出的单一优控PAHs在不同地区、不同时期的粒径分布进行了比较和讨论。总优控PAHs和单一优控PAHs化合物均趋向于吸附在小粒径颗粒物中,占总量47%~65%的总优控PAHs分布在粒径小于1.1μm的颗粒物中,只有不到10%的总优控PAHs分布在粒径大于7.0μm的粗颗粒物上。     

炼焦过程中多环芳烃产生特性的研究

对炼焦过程中产生排放的多环芳烃特性进行分析研究,利用超声波萃取和高效液相色谱技术,测定了单煤、配煤炼焦各阶段产生的16种PAHs的含量。研究结果表明,升温初期的1~4 h内PAHs的产生量最多,其中具有四环结构的居多,具有"三致"作用的苯并[a]芘超标排放,是PAHs的重要污染源之一。     

不同来源污泥热解油中多环芳烃分布特征

分析了4种不同来源污泥的热解油中16种EPA-PAHs生成分布,并探讨了污泥原样中自由赋存PAHs和污泥泥质特性（碳含量、H/C摩尔比、O/C摩尔比及挥发分含量等）的影响。结果表明,4种来源污泥热解油中均不同程度包含16种EPA-PAHs,∑EPA-PAHs含量分布次序为：工业印染污泥热解油（21.72 mg·kg^-1）>生活污泥热解油（14.10 mg·kg^-1）>造纸污泥热解油（13.72 mg·kg^-1）>食品污泥热解油（5.48 mg·kg^-1）,且以低环（2R）和中环（3R和4R）PAHs为主,其总量占∑EPA-PAHs的95%以上。热解油中PAHs含量高低与污泥自身赋存的自由PAHs含量具有一定关联;泥质特性对热解油中EPA-PAHs含量分布也呈现了不同程度影响,随着污泥泥质特性变化,3R和4R-PAHs含量变化规律较相似,均在碳含量为30.96%、H/C摩尔比为1.1、O/C摩尔比为0.33和挥发分为35.5%时达到最高水平;2R-PAHs含量在碳含量为20.75%、H/C摩尔比为1.44、O/C摩尔比为0.6和挥发分为46.3%时达到最高水平。     

焦作市土壤剖面多环芳烃的含量及分布特征研究

本文研究了焦作市博爱土壤剖面多环芳烃(PAHs)含量的分布特征。发现在美国EPA优先控制的16种PAHs中,检测出8种,PAHs主要分布在0—40cm土层中,PAHs总含量与土壤深度的增加无明显相关性。     

北京市大气颗粒物中多环芳烃的分布特征

用撞击式分级采样器同步采集了北京市城乡结合部、郊区的2003年4个季节的不同粒径大气颗粒物样品,用气相色谱-质谱分析了其中的多环芳烃,并对两个地区大气颗粒物中的多环片烃含量、分布及季节性变化特征进行了探讨。     

DISTRIBUTION OF PRIORITY POLYCYCLIC AROMATIC HYDROCARBONS IN THE SEDIMENT OF LAKE BALATON,HUNGARY

The determination of 13 PAH pollutants was carried out on sediment samples collected at 27 sites at the Lake Balaton, Hungary. The aim was to investigate the distribution patterns of PAHs and the correlation of source-sink relationship. Sediment samples were collected from the upper 10 cm and from 20 to 70 cm depth. The dry mass ratio of the fine grain-size fraction (<0.063 mm) and the coarse sand sediments (0.063–500 mm) were analyzed. Principal component analysis (PCA) was performed on the PAH compositional data for 110 samples to estimate the distribution of PAHs in different compartments. The average concentration of PAHs was found as 132 μg/kg dry weight (11–1734 μg/kg) for all sites and depth. Considering the harbors, at some sites, 930–950 μg/kg of total PAHs were obtained. The ratio of phenantrene/anthracene (PHE/AN) and fluoranthene/pyrene (FA/PY) indicated that most of the samples showed pyrogenic origin. It can be established that the upper 10 cm of the sediment is significantly more polluted than the deeper layers. The interim sediment quality guideline (ISQG) values and the probable effect level (PEL) were used to compare our findings with other data. No concentrations of PAHs were found higher than either ISQG and PEL values of samples collected inside of the lake, so the sediment has not been associated with adverse biological effects. However, the maximum concentrations of 7 out of 9 PAH compounds found in samples of harbors were higher than ISOG values but lower than PELs. Analysis of the harbor sediments revealed an elevated amount of contamination probably derived from the fuel of ships.     

POLYCYCLIC AROMATIC HYDROCARBONS IN BALTIC SEA BIVALVES

Concentrations of parent polycyclic aromatic hydrocarbons (PAHs) in the bivalves Macoma balthica and Astarte borealis were studied as an indication of the state of the Baltic Sea. Samples were collected between 1999 and 2001 from the Gulf of Finland, the Eastern Gotland Basin, and the Southern Baltic Proper. PAHs were quantified by liquid chromatography with fluorescence detection. The sum of 12 PAHs varied between 44 and 298 ng/g (ww), with the most contaminated bivalves found in Hanö Bight (the Bornholm basin). High-molecular-weight PAHs predominated among the PAHs. The PAH profiles of M. balthica differed from those determined in sediment from the same area. Both pyrolytic and petrogenic origins were indicated. Toxic equivalency factors evaluated as benzo[a]pyrene equivalents (BaPEs) were used to assess the PAH contamination. BaPEs were higher than values for M. balthica found in the southern part of the Gulf of Finland in 1995 and much lower than values measured in 1987 after the most serious oil spill in the Gulf of Finland in the past 25 years.     

SOURCE APPORTIONMENT OF POLYCYCLIC AROMATIC HYDROCARBONS IN ROAD DUST IN TOKYO

This study was aimed at investigating source apportionment of PAHs in urban road dust. Seven kinds of PAHs sources were defined: diesel vehicle exhaust, gasoline vehicle exhaust, tire, asphalt-pavement, asphalt or bitumen, petroleum products excluding tire and asphalt, and the combustion products except for those in vehicle engines. Using cluster analysis combined with principal component analysis, 189 source data were classified into 11 source groups (S1–S11) based on the content percentage of 12 individual PAHs (12-PAH profiles). Thirty-seven dust samples on nine streets in Tokyo were collected and analyzed for 12-PAH profiles. In order to estimate the PAHs, contributions of S1–S11 to dust samples, the multiple regression analysis was performed. The 12-PAH profiles of each dust sample and those of 11 source groups were applied as dependent and independent variables, respectively. We defined the comparative contribution of each source group as the ratio of each regression coefficient to the sum of them. The result revealed that diesel vehicle exhaust, tire, and pavement were the major contributors of PAHs in the road dust.     

POLYCYCLIC AROMATIC HYDROCARBONS IN BALTIC SEA SEDIMENTS

Present concentrations of parent polycyclic aromatic hydrocarbons (PAHs) were studied in bottom sediments of the Baltic Sea. Sediments were collected in 2001 and 2002 from the Gulf of Finland, the Northern Baltic Proper, the Eastern Gotland Basin, the Southern Baltic Proper, and Kattegat. Parent PAHs were quantified by liquid chromatography with fluorescence detection. The sum of 13 PAHs in 1 cm slices in the first 5 cm varied between 64 and 5161 ng/g (dw) depending on the bottom type. The most contaminated area was in the Eastern Gotland Basin, and the most abundant PAH components found in sediments were fluoranthene, benzo[b]fluoranthene, benzo[ghi]perylene, and indeno[1,2,3-cd]pyrene. The studied PAHs were both pyrolytic and petrogenic in origin. In addition, the concentrations of indeno[1,2,3-cd]pyrene and benzo[ghi]perylene indicated a contribution from diesel engines, which may indicate pollution caused by the steadily increased shipping in the Baltic Sea.     

BIOTA ACCUMULATION OF POLYCYCLIC AROMATIC HYDROCARBONS IN BENIN COASTAL WATERS

The contamination levels of 12 US-EPA polycyclic aromatic hydrocarbons (PAHs) from the tri-aromatics to the hexa- aromatics in biota and sediment of Cotonou's lagoon and Benin's continental shelf waters are identified in this paper.

PAHs were analyzed by gas-chromatography coupled with mass spectrometry (GC-SM). Total lipid contents (TLC) were measured for biota, and total organic carbon content (TOC) for sediment.

Total PAH concentrations obtained for organisms ranged between 15 and 102ngg^{? 1}, with mussels accumulating the highest concentrations of PAHs. The lower–molecular-weight (LMW) 3 ring PAHs were predominant in all biota and showed similar distribution patterns. Phenanthrene accounts for 76% of total bioaccumulation factors (BAFs). Biota and sediment accumulation factors (BSAFs) showed that the mussels are exposed to the LMW PAHs more than to the hydrophobic higher-molecular-weight (HMW) PAHs in the Benin coastal waters.     

IN VITRO INTESTINAL TRANSFER AND METABOLISM OF POLYCYCLIC AROMATIC HYDROCARBONS

Though polycyclic aromatic hydrocarbon (PAH) transfer through intestinal epithelium seems principally governed by transcellular diffusion, other mechanisms may interfere. Several studies suggest a PAH metabolism via CYP450, particularly in liver, but only few data are available regarding intestinal barrier. This in vitro work aimed at studying PAH metabolism and its consequences on the transfer in the intestinal epithelium according to molecule physicochemical properties. It used ¹⁴C-labeled benzo[a]pyrene, pyrene, and phenanthrene. Medium analysis proved a metabolism in intestinal cells for each PAH. Parallel metabolism appeared to play a positive role in the intestinal transfer of PAHs under different forms: ¹⁴C from benzo[a]pyrene, pyrene, and phenanthrene were respectively transferred 26, 4, and 2 times less when cells were incubated with CYP450 inhibitors. Generally speaking, the faster and the higher a PAH crosses intestinal barrier, the less metabolized it will be.     

纳滤膜对水中多环芳烃类物质的分离特性研究

以萘、菲、荧蒽为对象研究了不同操作压力、pH、离子强度条件下纳滤膜对多环芳烃类物质的去除特性.结果表明,纳滤膜对PAHs类物质的截留率达到90%以上,是有效的分离方法.选用BDXN-70去除PAHs的最佳处理条件为:操作压力0.4MPa,pH为10,离子强度(Ca2+)为0.4mS·cm-1.     

POLYCYCLIC AROMATIC HYDROCARBONS IN THREE VARIETIES OF FISH FROM KUWAIT BAY

The study reports levels of parent polycyclic aromatic hydrocarbons (PAHs) in three native fish species—mullet, sea bream and tonguesole—captured from Kuwait Bay (KB) area and outside the Bay from the Auha area between October 2004 and June 2005. KB has witnessed rapid urban and industrial development since the discovery of oil and is considered to be the most productive area in the region. Whole fish analysis revealed that the lower molecular weight PAHs (pyrene, fluoranthene and phenanthrene) were present in all the three varieties of fish in considerably higher amounts. Other low molecular weight PAHs like acenaphthylene, acenaphthene and anthracene were also present but in lower concentrations. Among the higher molecular weight PAHs, the frequency of detection of benzo(a)anthracene and chrysene was high and were present in high concentrations, whereas Benzo(k)fluoranthene and benzo(a)pyrene were not frequent in detection. The contamination of Σ PAHs was higher in the winter season in mullet and sea bream but in tonguesole a reverse pattern was found. Tonguesole from KB had the highest Σ PAHs suggesting that this bottom dwelling species can be used as an indicator of sediment pollution in the area. The observed seasonality in ∑ PAHs concentration in fish coupled with species difference may be related to difference in metabolic disposition of pollutants and their habitats.     

ALIPHATIC,POLYCYCLIC AROMATIC HYDROCARBONS AND NITRATED-POLYCYCLIC AROMATIC HYDROCARBONS IN PM 10 IN SOUTHWESTERN MEXICO CITY

A sampling campaign of airborne particles ≤ 10 μ m (PM ₁₀ ) was carried out from February to April of 2004 at the Universidad Nacional Autónoma de México in southwestern Mexico City. The average PM ₁₀ mass concentration was 51 ± 14 μ g m^?3. Extracted organic matter was determined, with a mean of 6.5 ± 1.7 μ g m^?3, which represents 12.9% of PM ₁₀ mass concentration. The standard additions method was used on real samples at four concentration levels for 13 n-alkanes, 14 PAHs and 5 nitro-PAHs. The average concentration for the sum was 99.04 ng m^{? 3} for n-alkanes, 4.9 ng m^?3 for PAHs and 710 pg m^{? 3} for nitro-PAHs. Higher concentrations of n-alkanes > C ₂₄ were found, indicating biogenic emissions as the dominant source. Coronene, benzo[ghi]perylene, benzo[b+j+k]fluoranthenes and indeno[1,2,3-cd]pyrene were the most abundant PAHs, suggesting a strong contribution from incomplete combustion of gasoline. The PAHs considered for calculating BaPE represented 52% of the total PAHs analyzed. The presence of 9-nitroanthracene indicates direct emission from diesel combustion and heterogeneous nitrating reactions on sorbed particles, while 2-nitrofluoranthene, indicates gas-phase reactions with fluoranthene, hydroxyl (OH^?) and/or nitrate (NO ₃ ^?) radicals in the presence of nitrogen oxides (NOx).