大气降尘中多环芳烃的分布特征及源解析

为探讨大气降尘中多环芳烃的污染水平和来源的解析,于2008年冬、春、夏、秋四个季节采集了北京昌平地区大气降尘样品,采用超声抽提方法,使用GC/MS测定了样品中PAHs的含量。结果表明,冬、春、夏、秋四个季节样品中多环芳烃总量分别为18.6μg/g、17.3μg/g、15.1μg/g和11.0μg/g,单体化合物均值分别为1.04μg/g、0.96μg/g、0.84μg/g和0.61μg/g。与其他城市监测结果比较可知:昌平地区大气降尘中PAHs含量相对较低。使用多种方法对降尘中的PAHs来源进行解析,结果表明:化石燃料燃烧在不同季节中的贡献相对稳定,燃煤在冬季为多环芳烃主要来源之一,在其他季节贡献相对较低。     

浙江台州典型电子废弃物无序拆解区土壤多环芳烃污染风险评估

电子废弃物的无序拆解会导致其中多环芳烃(polycyclic aromatic hydrocarbons, PAHs)的无规律释放,进而对周边生态环境和人体健康构成威胁。为了量化电子废弃物无序拆解区土壤中PAHs的含量及其对人体健康的风险,本研究从浙江省台州市路桥区某典型电子废弃物无序拆解区采集了3个作坊式电子废弃物拆解点、3个作坊式塑料或金属加工点和1个电子废弃物拆解尾渣倾倒点的土壤样品,以气相色谱-质谱联用法和美国环保署规定的暴露量化及风险表征方法为分析手段开展PAHs含量分析及其风险评估。结果发现:上述7个土壤样品PAHs的总量范围为32.62～1053.71μg/kg,平均为414.05μg/kg,其中一个作坊式电子废弃物拆解点的PAHs含量属于重污染级别,土壤存在强烈的环境风险,单体菲(Phe)、蒽(Ant)、荧蒽(Fla)和芘(Pyr)对环境风险的贡献率最大。此外,PAHs通过不同途径对人体造成的健康风险程度为呼吸途径﹥皮肤接触﹥经口途径。结果表明,电子废弃物无序拆解区土壤PAHs污染急需建立相关环境管理措施及污染控制标准,逐步规范电子废弃物无序拆解活动。     

三峡库区典型次级支流表层沉积物中PAHs的分布特征及来源分析

本文表征了三峡库区典型次级支流(梁滩河)表层沉积物中18种多环芳烃(PAHs)的浓度,并对其分布特征和污染来源进行了探讨。18种PAHs的总浓度(∑18 PAHs)范围为198.5～4349 ng/g-dw(干重),平均浓度为1441ng/g,中值为1160 ng/g。与其他地区沉积物污染情况相比,梁滩河沉积物中PAHs浓度处于中等偏低的污染程度,支流污染程显著高于干流,流经城镇的右支污染程度显著高于流经农村或人口较少的左支和主干流。大部分采样点以高环(4～6环)PAHs污染为主。PAHs源解析结果表明,梁滩河表层沉积物中PAHs污染以燃烧源为主,主要源于化石燃料和生物质的不完全燃烧。沉积物中苯并[a]芘的毒性当量因子(TEF)值为39.38～384.37 ngTEQ/g,平均值110.94 ngTEQ/g。生态风险评价的结果表明,右支流的两个采样点R3和R4点沉积物中PAHs可能存在生物负效应影响,R4点的高风险可能与附近白市驿机场污染有关。     

农田土壤中多环芳烃的高效液相色谱法测定

采用快速溶剂提取(ASE)—凝胶渗透色谱(GPC)—高效液相色谱法测定农田土壤中的多环芳烃(PAHs)。优化了ASE的提取溶剂和GPC的净化时间,方法具有良好的精密度和准确度,拥有良好的线性范围和检出限。对济南市某农田土壤样品进行了测定,共检出5种PAHs,总浓度为26.8μg/kg,参照Maliszewska-Kordybach土壤中PAHs污染分级方法,属于无污染水平,同时参考荷兰土壤质量标准中10种PAHs标准限值,均未超标。     

大庆地区总悬浮微粒中苯溶物及多环芳烃的测定与评价

通过对大庆地区总悬浮微粒（TSP）中主要化学组成──苯溶物、多环芳烃的测定分析得知：苯溶物占TSP的百分含量，年均值为10．31％，在空气中的平均浓度为12．5μg／m3。与北京燕山地区1983～1984年3个生活区（迎风、东风、东炼）苯溶物年平均值比较，大庆地区苯溶物含量较低。而对总悬浮微粒中多环芳烃的测定结果可明显看出各点采暖期苯并（a）芘、多环芳烃总量的浓度虽都明显高于非采暖期，但其致癌强度和浓度都比北京市、太原市及兰州市弱、低。     

多环芳烃污染农田土壤生态修复标准研究——辽宁省地方标准(DB 21/T 2274-2014)的建立及其依据

为指导正确评价多环芳烃污染农田土壤生态修复效果及环境风险,根据辽宁省农田土壤多环芳烃污染状况、多环芳烃污染农田土壤生态修复技术特点,参考国内外相关标准,应用生态风险模型,建立辽宁省地方标准(DB 21/T 2274-2014)——多环芳烃污染农田土壤生态修复标准,提出了生态修复完成后农田土壤中总多环芳烃浓度和苯并[a]芘环境当量总浓度限值。主要内容为:生态修复完成后农田土壤中总多环芳烃浓度低于2 mg/kg,生态修复完成后农田土壤中苯并[a]芘环境当量总浓度低于0.53 mg/kg。     

大气颗粒物中多环芳烃污染特征及防治对策

介绍了大港油田大气颗粒物和多环芳烃的污染现状,并对大港油田地区大气特征构成及大气颗粒物中多环芳烃的污染特征作了初步分析,得出大港油田地区大气颗粒物中多环芳烃污染类型为燃油型,并据此提出了防治多环芳烃污染的相应对策。     

四川省南充市大气中多环芳烃的分布

用超声波萃取，抽滤，减压蒸发浓缩，硅胶柱净化，再逍缩至干，定客溶解的方法处理了南充市5个监测点冬，夏季乘集的大气颗粒物样品，然后用高效液相色谱法分析其中9种多环芳烃含量，大气中苯并[a]芘的年平均含量为31．5ng/m3，略低于成都市1988年测定的年平均值，南充市大气中多环芳烃的主要来源是居民生活用煤，其次是汽车尾气，改变燃料结构，集中供热，加强城市交通管理，是减少多环芳烃污染的途径。     

水环境多环芳烃污染溯源研究

基于正定矩阵因子分解（Positive Matrix Factorization,PMF）模型对石马河河口及滨岸带中多环芳烃（Polycyclic aromatic hydrocarbons,PAHs）污染来源及贡献率进行解析,分别于2021年4月（平水期）和7月（丰水期）采集地表水及表层沉积物水样进行研究分析。结果表明：该研究区内PAHs污染的来源主要包括原油泄漏、煤炭燃烧、交通运输及生物质燃烧等,其中,交通运输源对研究区沉积物中PAHs的贡献率超过60%;交通运输及煤炭燃烧源对地表水中PAHs的贡献率之和接近80%;原油泄漏与交通运输源对研究区悬浮颗粒中PAHs的贡献率之和接近70%。研究结果可为石马河地区水资源绿色开发与PAHs污染治理提供一定依据。     

西溪湿地底泥质量现状与生态风险初步评价

为了解西溪湿地底泥质量现状,2012年9月采集保护区内不同干扰类型的底泥样本,测试了底泥中重金属和POPs中PCBs、OCPs和PAHs的含量,并对湿地底泥污染进行了生态风险初步评价。结果表明,底泥中未检出PCBs和OCPs,但检测出14种EPA优控PAHs,总PAHs的浓度范围为115.9～217.8 ng·g^-1,低于潜在生态风险的效应区间低值ERL,其中列入中国＂水中优先控制污染黑名单＂的7种PAHs均有检出并且其总量占∑PAHs 1/2左右（平均为50.08%）;底泥中8种重金属含量平均值低于《土壤环境质量标准》（GB 15618—1995）的二级标准,但Hg、Zn、Pb、Ni含量在多个位点已超过一级标准;分别采用土壤背景值和国家一级标准为参比值对湿地底泥中重金属进行单因子污染风险指数评价,发现分别有7种和4种元素的污染指数大于1;综合分析不同干扰类型的底泥质量,发现底泥疏浚能有效降低有机质含量、全氮和PAHs含量,但对全磷、重金属含量则无明显效果,封闭水体的干塘措施能显著减少污泥量和有机物含量。研究结果表明,西溪湿地底泥中高环PAHs和重金属污染水平可能对西溪湿地生物具有潜在的生物毒性作用及不利的生态影响效应,其疏浚底泥农用则无生态风险。     

The impact of urbanization on tropical mangroves (Fortaleza,Brazil): Evidence from PAH distribution in sediments

This investigation represents the first environmental diagnosis of the distribution and sources of polycyclic aromatic hydrocarbons (PAHs) in sediments from a tropical mangrove in Fortaleza, northeastern Brazil. Sediment cores from six sampling stations in the Cocó and Ceará Rivers were retrieved in June-July 2006 to determine 17 priority PAHs. The total PAH concentrations (Σ_PAHs) ranged from 3.04 to 2234.76 μg kg^?1(Cocó River) and from 3.34 to 1859.21 μg kg^?1 (Ceará River). These levels are higher than those of other cities with more industrial development. PAH concentrations did not reach probable effect levels (PELs). However, from 4.5 to 87.5% of individual PAH concentrations can occasionally cause adverse biological effects for aquatic organisms. The PAH molecular ratios indicate that the PAHs in the sediment core were derived mainly from petroleum, wood, and charcoal combustion (pyrogenic source), and that atmospheric deposition and urban runoff may serve as important pathways for PAH input to the sediment. Clearly, the Σ_PAHs in sediments collected in the Cocó and Ceará Rivers indicate that ongoing pollution is more severe than past pollution.     

Management of Urban Road Runoff Containing PAHs: Probabilistic Modeling and Its Application in Beijing,China1

Abstract: Pollutant loading from storm runoff is considered to be an important component of nonpoint source pollution in urban areas. In developing countries, because of the accelerated urbanization and motorization, storm runoff pollution has become a challenge for improving aquatic environmental quality. An effective storm runoff management plan needs to be developed, and questions concerning how much and which proportion of a storm should be treated need to be answered. In this study, a model is developed to determine the fraction of storm runoff that needs to be treated to meet the discharge standard within a given probability. The model considers that the pollutants can be mobilized during the early stage of a storm. The model is applied to a field study of polycyclic aromatic hydrocarbons (PAHs) in road runoff in Beijing, China. In this case, the probability that the PAH load will be mobilized with suspended sediments by the earlier portion of the flush is 73%. Given the high PAH loading in the study area and the referenced discharge standard, the probability that the entire runoff should be captured and treated is 94%. Thus, urban planners need to consider treatment systems for the majority of the storms in this area, whether the PAH load is in the first flush or not. This methodology can be applied to other regions where PAH loads may result in different management outcomes.     

A critical appraisal of PAH indices as indicators of PAH source and composition in Elelenwo Creek,southern Nigeria

The survey of polycyclic aromatic hydrocarbons (PAHs) and their relation to potential pollution sources were investigated in suspended particulate matter (SPM), surface waters, and sediments from Elelenwo Creek, southern Nigeria. Total PAH concentrations varied from 2,021.35 to 3,926.84 μg/kg dry weights in SPM and from 4,238.00 to 5,490.84 μg/kg dry weights in sediments. Furthermore, concentration levels of PAHs varied from 720.46 to 857.65 μg/l in the surface waters, which indicates that the aquatic ecosystem is polluted by PAHs. The 2, 3-ring PAHs were not dominant in SPM (34.73%), surface water (40.09%), and sediments (22.43%). While anthracene was more abundant, of the 2, 3-ring PAHs in SPM, the most abundant in the surface waters and sediments were fluorene and acenaphthylene. Four origin indices or concentration ratios of PAH isomer pairs were used to evaluate the suitability of these compounds as tracers to distinguish between the contamination arising from different sources. A critical appraisal of the PAH indices, therefore, suggested that biomass combustion is the major PAH source in the environmental matrices. Relative PAH patterns in the environmental matrices were also evaluated using principal component analysis, and were found to correlate with the PAH patterns of the different potential contamination sources.     

Vehicular Contamination of Dust in Amman, Jordan

Road dust from four traffic areas; the city center, tunnels, closed car parks and a residential area was collected from the urban part of Amman and analyzed for polycyclic aromatic hydrocarbons (PAH) and heavy metals content.Total PAH and selected heavy metals were in the range of a few gg^–1. The distribution of PAH was controlled by the arid climatic conditions. PAH distribution in the street dust tended to be dominated by 4- and 6-ring PAHs with significantly less 2- and 3-ring PAH reflecting volatilization of the latter under the hot and dry climatic conditions. However, both PAH and heavy metal concentrations were affected by the densities and conditions of traffic activity at the various sites. Generally, the highest concentrations of both PAH and heavy metals were found in the tunnels and the lowest in the residential areas.Significant correlation between PAH and total organic matter (TOM), lead and cadmium indicated that PAH and heavy metals in street dust of heavily traffic areas are strongly affected by automobile exhaust emission and that those in the residential areas have another source, most probably street material erosion.     

对电解铝厂周边氟污染的环境影响评价

通过测定广西某电解铝厂周边大气、土壤和农作物中氟化物含量,对该厂周边的氟化物污染进行了评价,结果表明：电解铝厂周围大气氟污染与采样点的方位成显著相关关系;农作物玉米叶片氟污染主要来自于电解铝厂无组织排放的氟化物,而土壤中总氟含量除受大气中氟化物的影响外,还与当地的地质构造、土壤类型等因素有关,与主导风向无明显的相关关系,土壤中水溶氟含量与采样点到电解铝厂距离呈负相关。     

Effect of electrokinetics on the bioaccessibility of polycyclic aromatic hydrocarbons in polluted soils

Bioaccessibility is one of the most relevant aspects to be considered in the restoration of soils using biological technologies. Polycyclic aromatic hydrocarbons (PAH) usually have residual fractions that are resistant to biodegradation at the end of the biological treatment. In some situations, these residual concentrations could still be above legal standards. Here, we propose that the available knowledge about electroremediation technologies could be applied to enhance bioremediation of soils polluted with PAH. The main objective of this study was to show that a previous electrokinetic treatment could reduce the PAH residual fractions when the soil is subsequently treated by means of a bioremediation process. The approach involved the electrokinetic treatment of PAH-polluted soils at a potential drop of 0.9 to 1.1 V/cm and the subsequent estimations of bioaccessibility of residual PAHs after slurry-phase biodegradation. Bioaccessibility of PAH in two creosote-polluted soils (clay and loamy sand, total PAH content averaging 300 mg/kg) previously treated with an electric field in the presence of nonionic surfactant Brij 35 was often higher than in untreated controls. For example, total PAH content remaining in clay soil after bioremediation was only 62.65 +/- 4.26 mg/kg, whereas a 7-d electrokinetic pretreatment had, under the same conditions, a residual concentration of 29.24 +/- 1.88 mg/kg after bioremediation. Control treatments without surfactant indicated that the electrokinetic treatment increased bioaccessibility of PAHs. A different manner of electric field implementation (continuous current vs. current reversals) did not induce changes in PAH bioaccessibility. We suggest that this hybrid technology may be useful in certain bioremediation scenarios, such as soils rich in clay and black carbon, which show limited success due to bioavailability restrictions, as well as in highly heterogeneous soils.     

Degradation of polycyclic aromatic hydrocarbons by combined chemical pre-oxidation and bioremediation in creosote contaminated soil

The ability of pre-oxidation to overcome polycyclic aromatic hydrocarbons (PAH) recalcitrance to biodegradation was investigated in creosote contaminated soil. Sand and peat artificially spiked with creosote (quality WEI C) were used as model systems. Ozonation and Fenton-like treatment were proved to be feasible technologies for PAH degradation in soil. The efficiency of ozonation was strongly dependent on the water content of treated soil samples. The removal of PAH by Fenton-like treatment depended on the applied H2O2/soil weight ratio and ferrous ions addition. It was determined that the application of chemical oxidation in sand resulted in a higher PAH removal and required lower oxidant (ozone, hydrogen peroxide) doses. The enhancement of PAH biodegradability by different pre-treatment technologies also depended on the soil matrix. It was ascertained that combined chemical and biological treatment was more efficient in PAH elimination in creosote contaminated soil than either one alone. Thus, the combination of Fenton-like and the subsequent biological treatment resulted in the highest removal of PAH in creosote contaminated sand, and biodegradation with pre-ozonation was found to be the most effective technology for PAH elimination in peat.     

Polycyclic aromatic hydrocarbon release from a soil matrix in the in vitro gastrointestinal tract

Soil ingestion is an important exposure route by which immobile soil contaminants enter the human body. We assessed polycyclic aromatic hydrocarbon (PAH) release from a contaminated soil, containing 49 mg PAH kg(-1), using a SHIME (Simulator of the Human Intestinal Microbial Ecosystem) reactor comprising the stomach, duodenal, and colon compartments. Polycyclic aromatic hydrocarbon release was defined as that fraction remaining in the digest supernatant after centrifugation for 5 min at 1500 x g. The PAH release in the stomach digest was only 0.44% of the total PAH present in soil, resulting in PAH concentrations of 23 micrograms PAH L(-1) chyme. The lower PAH releases in duodenum (0.13%) and colon (0.30%) digests, compared with the stomach digest, were thought to be attributed to combined complexation and precipitation with bile salts, dissolved organic matter, or colon microbiota. We studied these complexation processes in an intestinal suspension more in depth by preparing mixtures of 9-anthracenepropionic acid, a Bacillus subtilis culture, and cholin as model compounds for PAHs, organic matter, and bile salts, respectively. Bile salts or organic matter in the aqueous phase initially enhance PAH desorption from soil. However, desorbed PAHs may form large aggregates with bile and organic matter, lowering the freely dissolved PAH fraction in the supernatant. Using the model compounds, mathematical equations were developed and validated to predict PAH complexation processes in the gastrointestinal tract. Contaminant release and subsequent complexation in the gut is an important prerequisite to intestinal absorption and thus bioavailability of that contaminant. The data from this research may help in understanding the processes to which PAHs are subjected in the gastrointestinal tract, before intestinal absorption.     

小麦秸秆生物炭对石油烃污染土壤的修复作用

以小麦秸秆为原材料,在300℃下缺氧裂解3、6、8 h制备生物炭,比较了3种生物炭的产率、pH值、灰分以及C、H、N元素含量,表征了300℃、6 h生物炭的表面形态,并用其作为修复材料,对大港油田的石油污染土壤进行修复。结果表明,随裂解时间的延长,生物炭产率下降,pH值升高,灰分含量增加,H/C值下降,但产率、pH值、灰分和H/C值都是从3h到6h差异显著,6h到8h差异不显著。C元素含量先升高后下降。石油污染土壤经生物炭修复14 d和28 d后,总石油烃降解率分别为45.48％和46.88％,均显著高于对照组。修复14 d后土壤中的萘、苊、苯并[a]蒽、屈、苯并[b]荧蒽、苯并[k]荧蒽、苯并[a]芘、茚并[1,2,3-cd]芘也都有不同程度的下降,其中苯并[a]芘含量下降幅度达98.18％,其他几种PAH的降解率也都高于对照组,28 d后这些PAH的含量又有上升趋势。这说明小麦秸秆裂解时间对生物炭的性质有影响;300℃、6 h生物炭可以用来修复石油污染的土壤。     

饮用水中半挥发性有机物的定性检测

内江二水厂以沱江水为水源，本文通过对该水厂出厂水的液—液萃取，用色—质联机定性检测出９７种半挥发性有机物。结果表明：沱江水质的有机污染仍很严重