分子标志物参数在识别土壤多环芳烃(PAHs)来源中的应用

土壤中PAHs污染物的成因十分复杂,常见的污染源包括生物质的高温降解产物、石油等化石燃料及其不完全燃烧产物等,其输入方式主要有大气中所含PAHs的干、湿沉降、水体输入、固体废弃物排放等。不同成因的PAHs组成特征有一定差别,并可能具有独特的分子标志物或分子化合物组合特征,由此,可以根据环境介质中PAHs的组成特征判断污染物来源或成因类型。目前,分子标志物特征参数已成为追踪PAHs污染来源的有效手段。介绍了近年来国内外在运用PAHs分子标志物特征参数识别土壤中PAHs污染源方面的主要研究进展、应用潜力及存在的问题。     

PAHs and Petroleum Markers in the Atmospheric Environment of Alexandria City,Egypt

To evaluate the chemical fingerprint of hydrocarbons in airborneorganic matter in the arid environment of Alexandria City, Egypt,the compositions of aliphatic and aromatic compounds were determined in suspended particulate material collected from a street undergoing heavy traffic in central Alexandria and in bulkdeposition samples collected from a site representing an area increasingly influenced by human and industrial activities. Qualitative and quantitative characterizations of individual compounds were based on gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS) analyses. More than 100 organic compounds are quantified in each sample, including n-alkanes, isoprenoids, polycyclic aromatic hydrocarbons(PAHs), sulfur-bearing heterocyclics, steranes/diasteranes, terpanes and aromatic steroids. The use of hydrocarbon profilesand ratios for identifying sources and processes is discussed.The molecular distribution of alkanes revealed that the mainsource of these compounds is from petroleum contamination withtrace input of vascular plant wax. The PAH profiles, especiallythe relative abundance of alkyl-PAHs and sulfur-containing heterocyclics, showed that PAHs are chiefly derived from trafficsources. The results further indicated that diesel vehicles aremore important PAH sources than gasoline vehicles. In addition,the source fingerprint of fossil fuel biomarkers such as steranes, terpanes and aromatic steroids agreed well with thefingerprint of unburned lubricating oil, which are probably contributed to vehicle exhaust emissions.     

Assessment of the effect of aerial transport of salts on solonetzic process in the Black Sea region

The aerial deposition of salts is often considered as one of the sources of soil salinity; the amount and composition of the salts deposited from the air are studied. In this paper, the potential contribution of aerial salts to the development of the solonetzic process in the soils of the Black Sea region is analyzed. The wet and dry (with dust) depositions are considered separately. To reveal their influence on the potential development of the solonetzic process, special calculations with the use of cation exchange equations have been performed. It is shown that solutions of salts deposited from the air can lead to a very weak development of the solonetzic process. Their amount is only sufficient to ensure the exchangeable sodium percentage in soils from 0. ⁿ to 2–4% of the exchange capacity.     

Formation of polycyclic aromatic hydrocarbons in the smoke from heated model lipids and food lipids.

The contents of polycyclic aromatic hydrocarbons (PAHs) in the smoke from model lipids and food lipids during heating were determined and the mechanism of PAH formation was studied. A Rancimat oil stability analyzer was used as a model system for heating model lipids and food lipids at 220 degrees C for 2 h and for adsorption of smoke. The various lipid degradation products and PAHs in the smoke were identified and quantified by a GC/MS technique. Results showed that model lipids were more susceptible to smoke formation than food lipids during heating, but the PAH levels were lower for the former than latter. Methyl linolenate produced the highest amount of PAHs, followed by methyl linoleate, methyl oleate, and methyl stearate. Also, soybean oil generated a larger amount of PAHs than canola oil or sunflower oil. Benzene-like compounds were found to be possible precursors for PAHs formation. Several PAH derivatives were also present in heated model lipids and food lipids.     

The nature and origin of the aeolian mantles of central northern Nigeria

Evidence is presented here to show that the upland soils of central northern Nigeria are formed in aeolian mantles deposited by two aeolian processes: aeolian suspension (or dust) deposition and aeolian saltation (or dune sand) deposition. The soils to the south and west of Kano are largely the product of Harmattan dust deposition, whereas the northern soils appear to originate from dune sand migration from the Quaternary dune fields to the east of the study area. The spatial pattern of particle-size populations (or quanta) and quartz grain roundness characteristics, within the mantles and dune sands, indicates that considerable mixing of dune sands and dust has occurred in the formation of these mantles.     

Characterization of Polycyclic Aromatic Hydrocarbons Created in Lubricating Oils

Used lubricating oils are majorsources of polycyclic aromatic hydrocarbons (PAHs) inmarine environments. This study presents an improvedmethod for characterization PAHs in used lubricatingoils. Recoveries of sixteen certified PAHs spikedinto used lubricating oil indicated this method wasmore precise and efficient than those reportedpreviously. Aromatic and aliphatic compounds in usedlubricating oil were extracted by dimethylsulfoxide,then separated by a silica gel column using hexane anddichloromethane as solvents. Finally, gaschromatography-mass spectrometry was used inqualitative and quantitative analysis of various PAHsin oil samples. Sixteen certified PAHs andeighty-three other PAHs were identified and quantified usingPAH standards and previously reported retentionindices as references. The improved method was usedto determine PAH profiles in lubricating oil samplescollected from a gasoline-driven automobile aftervarious driving distances. One hundred and eightyaromatic compounds, including ninety-nine PAHs, wereidentified by the gas chromatographic method. Theseresults suggested that the new method was superior tomethods described in previous studies. Theconcentrations of PAHs, including the comparativelytoxic 5-ring PAHs, increased rapidly even after theautomobile had only been driven for a short distance. 2- and 3-ring PAHs, most of them are alkylated,dominated the PAH profiles of the collected oil samples.     

Biological activity and chemical composition of the essential oil from Jamaican Hyptis verticillata Jacq

The chemical composition of the essential oil obtained by hydrodistillation from the aerial parts of Hyptis verticillata Jacq. was elucidated by a combination of GC and GC-MS analyses. The oil was dominated by the sesquiterpenoids cadina-4,10(15)-dien-3-one (15.1%) (1) and aromadendr-1(10)-en-9-one (squamulosone) (30.7%) (2). The oil exhibited chemosterilant activities against the cattle tick, Boophilus microplus Canest., and toxic action against adult Cylas formicarius elegantulus Summer, the most destructive pest of sweet potato (Ipomoea species).     

太原小店污灌区农田土壤多环芳烃的污染特征及其来源

[目的]对太原小店污灌区农田土壤多环芳烃(PAHs)的污染特征及来源进行分析,为该区农田土壤环境质量评价及土壤污染防治对策的制定提供科学依据。[方法]采集太原小店污灌区15个表层土壤样品,利用GC/MS分析16种US EPA优控多环芳烃(PAHs)的含量,并对其来源和生态风险进行探讨。[结果]所有样品的16种PAHs均被检出,其检出率为100%。研究区农田土壤中总PAHs的浓度为0.315~7.661μg/g,平均值为3.568μg/g。在组成上,2,3环含量约占总量的64.2%,4环含量约占总量的14.2%,5,6环含量约占总量的21.6%,低环和中环PAHs含量所占的比例较高。根据特征比值法及调查结果判定,农田土壤中PAHs污染来源一方面与灌溉水质及灌溉历史有很大的关系,另一方面,主要通过燃煤或化石燃料产生的PAHs在大气干湿沉降和风力输送作用下进入到土壤环境中。[结论]与国内外其他地区的相关研究比较,小店污灌区农田土壤PAHs含量处于中高等污染水平。依据Maliszewska-Kordybach建议的分级标准评价,该区域所有采样点PAHs总量均超标;但基于我国《土壤环境质量标准(征求意见稿)(GB15618-2008)》提出的16种多PAHs污染物总量的农业用地标准值,该区域均未超出此标准。     

Model Simulations of the Alkaline Dust Distribution from Estonian Sources over the Baltic Sea Basin

The model calculations of oil-shale fly ash deposition from the Narvapower plants (north-eastern Estonia) are performed using the models HILATAR (regional scale) and AEROPOL (local scale). The modelling results are compared with air quality monitoring results from the observation stations in the Baltic Sea region and with the results of snow pollution study in Estonia. It was found, that although the bulk of the ash emitted is deposited near the sources, the emissions are large enough to create remarkable background deposition in the Baltic Sea region. The uncertainties related to the effective particle size are discussed and corresponding sensitivity studies are performed.     

Distribution of polycyclic aromatic hydrocarbons (PAHs) in floodplain soils of the Mosel and Saar River

Background, Aim and Scope  Polycyclic aromatic hydrocarbons (PAHs) have gained serious attention in the scientific community due to their persistence and toxic potential in the environment. PAHs may pose a risk to ecosystem health. Along the Mosel River/Germany, a tributary of the river Rhine, PAHs were found at significantly high concentrations (> 20 mg kg⁻¹, German national guideline value Z2, LAGA 1998). These high concentrations were detected during the construction of a storm water retention basin, in which the contaminated soils had to be removed and treated as hazardous waste. This resulted in higher construction costs for implementing flood prevention measures, but did not address the origin of these PAHs and its distribution along Mosel River. Hence, for future flood prevention projects, it is necessary to estimate the extent of PAH contamination along the Mosel River. The aim of the study is to determine the extent of PAH contamination in soils collected along Mosel and Saar River, and to obtain a first insight into the origin of the PAH contamination in this region. Materials and Methods  In total twenty seven sample sites were investigated. Forty two single samples were collected along a 167 km distance of Mosel River and six samples were collected along a 20 km distance of Saar River. Soil samples were collected at a depth of 0 to 2 m with a stainless steel corer (▫ 8 cm). Each 2 m sample was further separated into two sub-samples (0–1 m and 1–2 m). The sixteen EPA PAHs and three additional PAHs (1methylnaphthalene, 2methylnaphthalene and perylene) were analysed with gas chromatography mass spectrometry (GC-MS). For soil characterisation, total organic carbon (TOC), grain size, microscope and X-ray diffraction (XRD) analysis were performed. Results  Grain size for all soil samples was classified as a mixture of sand and silt. XRD analysis showed that all samples were dominated by quartz. Some clay minerals, such as illite and montmorillonite and feldspars, i.e. anorthoclase and orthoclase, were found in minor quantities. TOC ranged from 0.1% to 13%. Microscope analysis showed black coal particles in the majority of the soils collected from the Saar River and part of the Mosel River (downstream of the confluence of Saar and Mosel River). The black particles were not found further upstream along Mosel River. The sum of nineteen PAHs in the soil samples was up to 81 mg kg⁻¹ dry weight (dw). Most soil samples showed a relationship between the presence of coal particles and PAH concentrations. Discussion  Elevated PAH concentrations were found in all soil samples collected from Saar River and downstream Mosel River. Due to former coal mining activities in the Saarland, Germany, there is a strong evidence that the majority of the PAH contamination in the soils downstream Mosel River are linked to these mining activities. Upstream Mosel River coal particles were hardly found although PAH concentrations were high. Therefore another PAH source has to be responsible for these concentrations. PAH distribution patterns indicate a pyrogenic PAH input upstream Mosel River and a mixed input (petrogenic and pyrogenic) downstream Mosel River. Conclusions  Due to PAH distribution patterns, the contamination along the upstream of the Mosel River is probably linked to atmospheric depositions and other sources not linked to coal mining activities. Downstream Mosel River the PAH distribution patterns reflect former coal mining activities. We could corroborate for the first time that coal mining resulted in a serious problem of an extensive PAH contamination at Saar and Mosel River floodplain soils. Recommendations and Perspectives  Coal mining activities have a strong impact on the neighbouring regions (Johnson and Bustin 2006, Short et al. 1999, Stout et al. 2002). It is known that coals exhibit relative high PAH concentrations, especially in the low molecular weight PAHs (Chapman et al. 1996, Radke et al. 1990). However, PAHs in coals are hardly bioavailable (Chapman et al. 1996) and hence may have less adverse effects on exposed biota. They can act as sink for other hydrophobic contaminants. For the assessment of the environmental impact, a detailed study of the sorption and desorption behaviour of PAHs linked to coal particles should be carried out. ESS-Submission Editor: Dr. Ralph Portier (rportie@lsu.edu)     

淮河上游全新世黄土-古土壤序列元素地球化学特性研究

在野外考察研究的基础上,对河南禹州全新世风成黄土-古土壤剖面系统采样,利用X-荧光光谱仪测定了常量元素和微量元素的含量及其变化,并与磁化率曲线、粒度变化曲线对比分析发现:常量元素氧化物比值钾钠比、残积系数和以Rb为代表的微量元素含量等随剖面层次呈规律性变化,即在古土壤层(S0)中含量最高,表土层(MS)中次之,在黄土层(L1、Lt、L0)中最低。硅铝率和Sr的含量表现出相反的变化规律。表明在全新世古土壤层和表土层形成时期,气候温暖湿润,成壤作用和次生粘化作用较强;在黄土堆积时期,气候比较干旱,沙尘暴频繁,成壤作用微弱。这些化学参数与磁化率曲线可以进行对比,表明成土过程中元素的迁移变化受全新世以来气候变化和成壤环境变化的控制。与黄土高原腹地的洛川剖面相比,淮河上游禹州剖面中绝大多数常量元素的含量较高,而绝大多数微量元素的含量偏低,磁化率也显著偏低,绝对值差别很大,粒度组成当中细沙成分含量很高,这说明淮河上游黄土物质来源与黄土高原地区明显不同。联系全新世时期黄河频繁泛滥、改道、沉积与黄淮平原盛行东北风形成流沙地的事实,认为淮河上游的黄土是黄河泛滥沉积物质经过风沙活动改造,由东北风力系统搬运而来的近源粉尘堆积,再经过就地风化或者成土改造而形成。     

某氮肥厂场地土壤PAHs污染特征研究

采用现场采样及室内测试方法对广州某氮肥厂原料车间和油库区土壤中16种优控多环芳烃（PAHs）的含量进行调查研究,分析了EPAHs含量及其组成特征和垂直分布特征,并在此基础上进行了源解析。结果表明,分析样品中∑PAHs范围在10-7795μg·kg,原料车间土壤中的∑PAHs小于油库区土壤中的,菲、芘、荧蒽、并（b）荧蒽、苯并（a）芘为主要污染物;油库土壤0-40cm的样品中16种PAHs均有检出,∑PAHs和单体分布基本一致;原料车间土壤∑PAHs和单体浓度随着地面深度的增加而减少。通过对单组分比值（菲／蒽,荧蒽／芘）的分析可以看出油库区土壤中PAHs来源于石油和燃烧源,而原料车间污染源主要为燃烧源。     

土壤中多环芳烃的分布特征及其来源分析

利用气相色谱法分析了南充市10个不同功能区表层土壤中美国环保署规定的16种优控多环芳烃（PAHs）的含量和组分特征,运用同分异构体比率揭示了其污染来源。研究表明,该区土壤中PAHs的含量在9.1～2269.1μg·kg-1之间,而且工业区的残留量大于农业区和居民区的残留量。按PAHs的环数来分,在工业污染区PAHs的含量总的趋势是四环〉二环〉三环〉五环〉六环;农业和居民区二环〉三环〉五环〉四环〉六环。该污染状况与国内外相关研究比较,处于中等污染水平。煤、木材和化石的燃烧是该地区土壤中PAHs污染的主要来源,苯并（a）蒽和菲是主要的超标化合物。     

Regional clarkes of chemical elements in soils of southern European Russia

Distribution patterns of 19 elements in soils of the southern part of European Russian were estimated on the basis of the analysis of more than 9000 soil samples; regional clarkes of the elements were compared with their global clarkes, The obtained data attest to the fact that southern Russia is characterized by increased concentrations of most of the microelements with a tendency for their rise in the recent decades. The great role of the aerial migration and deposition of elements results in the enrichment of the soils with technophilic elements, so that the geochemical convergence of the soils is observed. It can be concluded that natural element abundances in soils are subjected to the technogenic transformation reflecting the high rate of contamination of the biosphere.     

AS350B3e直升机航空喷施雾滴飘移分布特性

为了探究安装有AG-NAV Guía系统的AS350B3e直升机进行喷施作业时的雾滴飘移规律,以轻型机载北斗RTK差分系统获取的精准作业参数(时间、速度、高度、轨迹)为参考,进行了不同作业参数喷施试验。研究了该直升机以4种不同飞行速度范围进行单向式喷施作业时,对应的有效喷幅区域范围及雾滴飘移分布规律,对比了添加航空助剂对雾滴飘移距离及飘移量的影响。结果表明:有效喷幅区域的位置受自然风速和风向变化的影响,会向直升机航线下风向区域有不同程度的偏移;当直升机分别以70、90、100、120 km/h 4种速度参数进行喷施作业时,随着飞行速度的增大,有效喷幅宽度呈现先缓慢增大后急剧减小的趋势,100 km/h的飞行速度为有效喷幅宽度变化的峰值拐点;当侧风风速为1.1~2.3 m/s时,目标喷雾区的最小宽度在喷雾区域下风向水平距离27.61~48.94 m的范围内,且下风向受飘移影响距离均接近或小于下风向有效喷幅宽度,同时研究还发现雾滴粒径在200μm以下的雾滴更容易发生飘移,因此在作业时要预留至少50 m以上缓冲区(安全区)并合理选择航空喷头以避免药液飘移产生的危害;航空助剂的使用对于雾滴飘移量减轻效果显著,在同等作业条件下,添加航空助剂能够使雾滴飘移量减少33.94%。该研究结果可为直升机的喷施系统性能改进提供参考,对合理喷施农药、减少飘移、提高农药利用率具有重要意义。     

南四湖表层底泥中多环芳烃有机污染及其生态风险研究

通过对南四湖9个采样点表层底泥中16种美国EPA规定的优控PAHs的含量测定,分析了PAHs在南四湖表层底泥中的分布特征、来源,进而对其生态风险进行了评价。结果表明:河口区的PAHs含量最高,主要是受污染严重的入湖河流的影响。微山岛和二级坝附近表层底泥中PAHs的含量与湖内其他点位相比较高,且上级湖的含量要高于下级湖的含量。表层沉积物中PAHs主要来源于化石燃料的不完全燃烧,但也存在一定的石油污染。南四湖表层底泥中的PAHs生态风险很小,未对生物造成不利影响,属于轻微污染水平。     

江汉油田区典型农田土壤烃类降解微生物功能基因bssA的遗传多样性研究

油田区土壤易受烃类物质影响并可能富集了特异的石油烃降解微生物类群。针对江汉油田区5个不同油井口附近的典型旱地农田土壤,采用石油烃(Petroleum hydrocarbons,PHs)中苯系物代谢的关键功能基因-bssA(苯甲基琥珀酸合成酶基因)作为分子标识物,通过克隆文库结合末端限制性片段长度多样性(Terminal-restriction fragment length polymorphism,T-RFLP)的方法,研究该油田区土壤含有bssA基因的烃类降解微生物群落结构,并探讨其环境驱动机制。结果表明,土壤中PAHs含量在0.21~2.01mg kg~(-1)之间,石油烃污染程度较低。T-RFLP的分析表明不同土壤样品中的bssA基因多样性差异明显,PAHs(Polycyclic Aromatic Hydrocarbons,多环芳烃)含量最高土壤中bssA基因多样性最高,其优势bssA基因类群与硫酸盐还原菌或地杆菌有较近的亲缘关系。冗余分析进一步表明,土壤硝态氮、有效磷、PAHs含量均是影响bssA基因多样性的重要因子。这些结果表明:江汉油田区典型农田土壤中含有bssA基因的主要类群为β-变形菌和δ-变形菌,并与地杆菌属(Geobacter)、索氏菌属(Thauera)和固氮菌属(Azoarcus)具有较近的系统发育亲缘关系。这些微生物可能通过硝酸盐、硫酸盐及铁还原代谢过程降解土壤PAHs。     

PAHs in the Soils of a Mature,Mixed-Deciduous (Quercus-Fraxinus) Woodland and the Surrounding Pasture

A survey of PAHs in the soils of a mature,mixed-deciduous woodland and the surrounding pasturewas conducted along two transects. PAH `profiles'were not significantly different in the woodland soilcompared with the pasture. ΣPAH concentrations in thewoodland soil were significantly higher than soil fromthe surrounding pasture by a factor of 1.5–3 (P < 0.01), indicating enhanced deposition of PAHs to thesoil under the canopy via leaf litter, stemflow and/or through-fall. A deposition `edge effect' was onlyobserved at the windward edge of the canopy where thenumber and density of aerial and basal stems washighest (P < 0.05). The influence of predominantwest/south-westerly winds was observable in the lackof an edge effect at the leeward edges, and the higherΣPAH concentrations in the predominantly leewardpasture compared to the windward pasture (P < 0.05).     

Assessment of soil tolerance toward contamination with black oil in the south of Russia on the basis of soil biological indices: A model experiment

The effect of soil contamination with black oil added in amounts of 0.1, 0.5, 1.0, 2.5, 5, 10, 25, and 50% of the soil mass on the biological properties of ordinary and leached vertic chernozems, brown forest soils, and gray sands in the south of Russia was studied in a model laboratory experiment. It was shown that the soil contamination causes a drop in the catalase and dehydrogenase activities, the cellulolytic capacity, the number of Azotobacter bacteria, and the characteristics of the plant germination. The ordinary and vertic chernozems were more tolerant toward the contamination than the gray sands and brown forest soils. The changes in the biological soil properties in dependence on the degree of the soil contamination differed considerably for the soils with different properties (the chernozems, brown forest soil, and gray sands) and were similar for the soils with similar properties (the ordinary and vertic chernozems). One soil (the brown forest soil) could be more tolerant toward the contamination than another soil (the gray sands) at a given concentration of black oil (<2.5%) and less tolerant at another concentration of black oil (>2.5%). The ecologically safe levels of the soil contamination with black oil do not exceed 0.7% in the ordinary chernozems, 0.3% in the compact chernozems, 0.1% in the brown forest soils, and 0.06% in the gray sands.     

多环芳烃长期污染土壤的微生物强化修复初步研究

本研究通过室内模拟试验,以急性毒性较强的菲(Phe)和遗传毒性较强的苯并[a]芘(B[a]P)为代表性多环芳烃(PAHs)污染物,以不同C源、通气状况和水分条件为调控因子,对PAHs长期污染土壤的土著微生物强化修复进行初步研究。结果表明,搅动处理使污染土壤中Phe和B[a]P的降解率分别达59.44%和26.14%,而淹水处理使两者降解率分别达46.48%和13.27%。添加C源(淀粉和葡萄糖)处理提高了土壤中PAHs的降解率,且随着C源的施用量而增加。同时也发现污染土壤中PAHs降解菌和微生物总量呈正相关,并随着PAHs降解菌数量的增加,土壤中PAHs降解率也随之提高。可见,土壤中PAHs降解速率主要决定于PAHs的降解菌数量。