光催化降解土壤中多环芳烃

多环芳烃(PAHs)是一类广泛分布于土壤中的持久性有机污染物,其化学结构稳定,具有高疏水性、难降解性和三致毒性,多产生于交通运输、工业生产、垃圾焚烧等人为活动中。近年来,日益严峻的PAHs污染给土壤生态、食品安全和民众健康带来严重威胁。因此,对土壤PAHs污染的治理具有重要意义且亟待解决。在众多PAHs处理技术中,光催化技术凭借能耗低、操作简便、环境友好等优势,受到了研究者们的广泛关注。本文概述了PAHs的光催化降解机理与途径,综述了光催化修复土壤PAHs领域的研究进展,讨论了不同环境因素对催化剂降解效果的影响,并总结了当前光催化技术应用于土壤PAHs污染修复所面临的挑战。     

多环芳烃暴露的生物标志物——尿中羟基多环芳烃

多环芳烃(PAHs) 是典型的持久性有机污染物,在职业高PAHs 暴露环境下,容易诱发肺癌、皮肤癌等癌症。对PAHs 的暴露评价可为流行病学研究和污染物风险评价等提供有效的数据。由于暴露途径的复杂化,采用尿样中PAHs 的代谢产物———羟基多环芳烃作为标志物来综合评价人体对PAHs 的内暴露情况已经成为研究的热点。本文系统介绍了多环芳烃的吸收、代谢、尿中PAHs 代谢产物的主要存在形式、主要的生物标志物以及它们的主要影响因素。     

Fenton原位化学氧化法修复有机污染土壤和地下水研究

Fenton高级氧化技术在废水处理领域已得到深入研究.近年来,该技术在国外有机污染土壤和地下水原位修复中受到越来越多的重视,而在国内相关领域则鲜有报道.虽然国外已有工程试验,但目前对Fenton试剂降解土壤和地下水中有机污染物的研究尚处于基础阶段.本文主要综述了Fenton技术修复有机污染土壤和地下水的发展过程和反应基本机理的研究进展,并针对修复中存在的问题进行了展望.     

土壤样品中多环芳烃的GC-MS快速分析方法

多环芳烃(PAHs)是含有多个苯环并具有致毒、致癌和致突变作用的有机化合物,主要由人类的现代化活动产生,通过大气、水等的传递最终污染土壤,而严重污染的土壤会影响农业耕作,最终危害人类健康.美国环保总署确定了16种PAHs作为优先监测污染物,中国政府列出的"中国环境优先监测黑名单"中包括7种PAHs[1].     

短链氯化石蜡的分析方法、污染现状与毒性效应

作为一种新型有机污染物,短链氯化石蜡(SCCPs)在2006年被列入斯德哥尔摩公约持久性有机污染物(POPs)候选名单。2017年5月第8次《关于持久性有机污染物的斯德哥尔摩公约》缔约方大会上,SCCPs最终被列入了《公约》附件A受控POPs清单。我国是氯化石蜡(CPs)生产使用大国,其在环境介质中的含量处于较高水平。本文对SCCPs的分析方法、污染现状、环境中来源与释放及其毒性效应进行了综述,并针对目前存在的问题及研究需求进行了总结。     

高效液相色谱-荧光检测法测定土壤中的多环芳烃

多环芳烃(简称PAHs)是一类具有致癌、致畸以及能够诱导有机体突变的环境有机污染物。可靠的PAHs检测方法是研究其环境行为的重要保证。由于高效液相色谱-荧光检测法具有不需要高温、对某些PAHs有较高的分辨率和高灵敏度、柱后流出组分便于收集进行光谱鉴定等优点,近年来被广泛应用于PAHs的检测。实验在对美国环保局(USEPA)优先监测的15种PAHs污染物在土壤中的含量进行测定时,重点优化了梯度洗脱程序和检测波长程序。优化后的方法对15种PAHs的最低检出限为0.12～1.57 μg/kg,回收率为73%～126%,相对标准偏差为0.53%～3.57%。结果表明,该方法用于测定土壤中PAHs的含量,具有检出限低、灵敏度高和重复性好等优点,是一个较为可靠的检测方法。     

污染土壤电动修复技术研究进展

电动修复是一种新兴的原位土壤修复技术,主要用于有机及重金属污染土壤/场地的修复.本文作者介绍了电动修复污染土壤的技术原理;探讨了电动技术与Fenton技术、表面活性剂/助溶剂、超声波技术、微生物技术及渗透性反应屏障技术的联合应用;总结了土壤电动修复中,土壤pH不均衡及有机污染修复效率较低的问题.确定了电动技术与多种技术的联用为土壤修复的研究和应用趋向.     

石油废物处置场周边土壤中多环芳烃的测定及评价

土壤样品经微波萃取处理,采用GC-MS法对某地含油废水排放水泡周围土壤中多环芳烃(PAHs)的量进行测定,并与土壤中有机质的含量进行相关性分析。结果表明,表层土壤中PAHs污染主要是2~4环的低分子量的PAHs,未检出高分子量的PAHs。各采样点属于轻度污染和中度污染,总体评价为中度污染,污染水平与该地区中部土壤数据对比处于中低等程度。其来源可能是石油污染中低分子量PAHs随大气输送而产生,但也不能排除燃料燃烧污染的可能。本区域多环芳烃和有机质含量之间没有发现明显相关关系。     

外源微生物对PAHs污染土壤细菌群落结构的影响

研究了添加分枝杆菌(Mycobacterium sp.)、假单胞菌(Pseudomonas sp.)和混合菌(分枝杆菌和假单胞菌)对多环芳烃(PAHs)污染土壤中细菌群落结构的影响.采用DGGE研究土壤细菌群落结构及多样性的变化,通过测序鉴定细菌种类.研究结果表明:投加微生物能够改变土壤细菌群落结构的组成,促进或加强了有PAHs降解能力的菌株如假单胞菌、如微杆菌(Micrococcus sp.)的出现;投加微生物改变了土壤中的细菌多样性指数,分枝杆菌处理组的多样性指数变化稍大.研究结果为PAHs污染土壤的修复理论与技术进一步发展奠定理论基础,也为PAHs污染土壤修复中微生物的选择提供依据.     

全氟辛酸和全氟辛烷磺酸人体暴露途径解析及其污染控制技术*

全氟辛酸（PFOA）和全氟辛烷磺酸（PFOS）是人工合成全氟化合物的典型代表。近年来,大量的环境调查数据表明它们普遍存在于多种环境介质、生物体甚至人体中,呈现出全球分布的态势,具有环境持久性和生物富集性,对人体健康存在潜在的危害,已成为一类新的环境持久性有机污染物而引起人们广泛的关注。本文介绍了PFOA和PFOS的环境来源和传输途径,解析了人体暴露的三种主要途径以及在食物、饮用水和空气/灰尘中的污染现状,并就围绕着它们所开展的污染控制技术方面的研究进行了评述。在此基础上,通过分析目前研究中所存在的问题,对今后的发展方向和研究重点进行了展望。     

Sample preparation and analytical methods for polycyclic aromatic hydrocarbons in sediment

Polycyclic aromatic hydrocarbons (PAHs) are a large category of ubiquitous persistent environmental pollutants, some of them have strong carcinogenicity to human and animals. These pollutants can easily enter the river through multiple ways including rainfall, dry deposition and water washout, and deposit in the sediment. However, it is easy for them to re-enter the river water and pollute water sources, as well as aquatic animals and plants, bringing potential harm to human health. Therefore, it is requisite to accurately analyze the PAHs in sediment. In this review, the analytical methods of PAHs in sediment, focused on the methods of sample extraction, purification, concentration and determination, are summarized.     

Progress in the analytical research methods of polycyclic aromatic hydrocarbons (PAHs)

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are one species of persistent organic pollutants (POPs) with strong carcinogenicity and teratogenicity. They can be widely found in the environment, which cause great harm to the ecological environment. In addition, they endanger human health by polluting food from the natural environment and food processing. Therefore, it is necessary to accurately detect PAHs in various sample matrices, which requires the accurate, practical and rapid detection methods. This review aims to investigate the progress of research methods for PAHs, including pretreatment methods and detection methods. A summary analysis of different methods is performed by searching the literature on numerous methods for detecting PAHs published in various journals. There are many pretreatment methods for PAHs, such as solid phase extraction (SPE), cloud point extraction (CPE) and so on. The most commonly used methods for detecting PAHs are high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). Spectrophotometry, chromatography and chromatography-mass spectrometry have been used more frequently owing to their accuracy and convenience. At the same time, some immunological methods, such as immunosensormethods, enzyme-linked immunosorbent assays (ELISA), immunofluorescence, etc. are also widely used.     

Simultaneous Dispersive Liquid–Liquid Microextraction and Determination of Different Polycyclic Aromatic Hydrocarbons in Surface Water

Polycyclic aromatic hydrocarbons (PAHs) are a class of persistent organic pollutants of water, and their determination at trace levels in the aquatic ecosystems is essential. In this work, an ultrasound-assisted dispersive liquid–liquid microextraction (DLLME) procedure was suggested utilizing a binary dispersive agent for recovery of different molecular weight polycyclic aromatic hydrocarbons (PAHs) from waters. The detection was carried out by gas chromatography–mass spectrometry (GC-MS) as well as high-performance liquid chromatography with fluorescence and diode-array detection (HPLC-FD/PDA). The method was optimized for the extraction of analytes with respect to the mixture composition, ratios of components, ultrasonication time and centrifugation parameters. The analytical schemes for PAHs extraction from water samples using different ratios of extraction and dispersive solvents are reported. The mixture consisting of chloroform and methanol was applied for the extraction of PAHs containing two or three fused aromatic rings; the mixture of chloroform and acetonitrile is suitable for PAHs containing more than four aromatic rings. The mixture of chloroform:acetone + acetonitrile was applied in the universal scheme and allowed for the simultaneous extraction of 20 PAHs with different structures. The developed sample preparation schemes were combined with GC-MS and HPLC-FD/PDA, which allowed us to determine the analytes at low concentrations (from 0.0002 µg/L) with the recoveries exceeding 80% and relative standard deviations of about 8%. The developed methods for the determination of 20 PAHs were applied to the analysis of water samples from the Karasun Lake (Krasnodar), Azov Sea (Temryuk) and Black Sea (Sochi).     

Comparisons of soxhlet extraction, pressurized liquid extraction, supercritical fluid extraction and subcritical water extraction for environmental solids: recovery, selectivity and effects on sample matrix

Extractions of a polycyclic aromatic hydrocarbon (PAH)-contaminated soil from a former manufactured gas plant site were performed with a Soxhlet apparatus (18 h), by pressurized liquid extraction (PLE) (50 min at 100 degrees C), supercritical fluid extraction (SFE) (1 h at 150 degrees C with pure CO2), and subcritical water (1 h at 250 degrees C, or 30 min at 300 degrees C). Although minor differences in recoveries for some PAHs resulted from the different methods, quantitative agreement between all of the methods was generally good. However, the extract quality differed greatly. The organic solvent extracts (Soxhlet and PLE) were much darker, while the extracts from subcritical water (collected in toluene) were orange, and the extracts from SFE (collected in CH2Cl2) were light yellow. The organic solvent extracts also yielded more artifact peaks in the gas chromatography (GC)-mass spectrometry and GC-flame ionization detection chromatograms, especially compared to supercritical CO2. Based on elemental analysis (carbon and nitrogen) of the soil residues after each extraction, subcritical water, PLE, and Soxhlet extraction had poor selectivity for PAHs versus bulk soil organic matter (approximately 1/4 to 1/3 of the bulk soil organic matter was extracted along with the PAHs), while SFE with pure CO2 removed only 8% of the bulk organic matrix. Selectivities for different compound classes also vary with extraction method. Extraction of urban air particulate matter with organic solvents yields very high concentrations of n- and branched alkanes (approximately C18 to C30) from diesel exhaust as well as lower levels of PAHs, and no selectivity between the bulk alkanes and PAHs is obtained during organic solvent extraction. Some moderate selectivity with supercritical CO2 can be achieved by first extracting the bulk alkanes at mild conditions, followed by stronger conditions to extract the remaining PAHs, i.e., the least polar organics are the easiest organics to extract with pure CO2. In direct contrast, subcritical water prefers the more polar analytes, i.e., PAHs were efficiently extracted from urban air particulates at 250 degrees C, with little or no extraction of the alkanes. Finally, recent work has demonstrated that many pollutant molecules become "sequestered" as they age for decades in the environment (i.e., more tightly bound to soil particles and less available to organisms or transport). Therefore, it may be more important for an extraction method to only recover pollutant molecules that are environmentally-relevant, rather than the conventional attempts to extract all pollutant molecules regardless of how tightly bound they are to the soil or sediment matrix. Initial work comparing SFE extraction behavior using mild to strong conditions with bioremediation behavior of PAHs shows great promise to develop extraction methodology to measure environmentally-relevant concentrations of pollutants in addition to their total concentrations.     

PAH metabolism in the earthworm Eisenia fetida – identification of phase II metabolites of phenanthrene and pyrene

Polycyclic aromatic hydrocarbons (PAHs) are soil contaminants. Because of their high lipophilicity, PAHs are associated with the organic matter in the soil. Transformation of PAHs generates polar metabolites and the interaction with organic matter in the soil changes. The polar PAH metabolites are persistent, highly water-soluble and potentially leachable from the soil; the understanding of transformation of PAHs to polar metabolites in the responsible organisms is of great importance. Here, we present a study of transformation of the PAHs pyrene and phenanthrene, by the common earthworm Eisenia fetida. The study showed that E. fetida in hydroponic culture was able to transform PAHs to conjugated phase II metabolites. We detected phenanthrene and pyrene metabolites with single- and multiple-phase II-conjugated groups. Sulphate conjugates were excreted to experiment water, and glucuronide and glucoside conjugates and metabolites with several hydroxylations and multiple conjugations were detected in worm tissue. The results demonstrate that earthworms are able to transform PAHs to water-soluble phase II metabolites, which can be excreted to the surrounding environment.     

What is necessary for next‐generation atmospheric environmental standards? Recent research trends for PM2.5‐bound polycyclic aromatic hydrocarbons and their derivatives

The air pollution associated with PM_2.5 kills 7 million people every year in the world, especially threatening the health of children in developing countries. However, the current air quality standards depend mainly on particle size. PM_2.5 contains many carcinogenic/mutagenic polycyclic aromatic hydrocarbons (PAHs) and their derivatives such as nitropolycyclic aromatic hydrocarbons and oxygenated PAHs. Among them, environmental standards and guidelines have been set for benzo[a]pyrene by few countries and international organizations. Recent research reports showed that these pollutants are linked to diseases other than lungs, and new methods have been developed for determining trace levels of not only PAHs but also their derivatives. It is time to think about the next‐generation environmental standards. This article aims to (a) describe recent studies on the health effects of PAHs and their derivatives other than cancer, (b) describe new analytical methods for PAH derivatives, and (c) discuss the targets for the next‐generation standards.     

加速溶剂萃取-分子筛固相萃取-气相色谱-串联质谱法测定土壤中多氯萘北大核心CSCD

新污染物引发的环境和健康风险正逐步受到社会各界的广泛关注,我国第十四个五年规划和2035年远景目标纲要明确“重视新污染物治理”。作为新型的持久性有机污染物,多氯萘(PCNs)在土壤中通常处于痕量水平,一般需要经过多层硅胶柱/氧化铝柱等复杂的净化方法,再结合有效的分析手段才能实现准确测定。关注土壤中多氯萘分离分析方法可以为掌握和监管其在土壤中的污染状况提供技术和方法支持。研究以13X分子筛作为固相萃取吸附剂,评价了其对多氯萘的净化效果。研究发现:使用正己烷作为上样溶剂和淋洗剂,10 mL二氯甲烷/正己烷(2∶15,v/v)为洗脱溶剂,可以实现PCNs与脂类大分子等干扰物的选择性分离,且多氯萘内标的平均回收率为56.1%~88.0%。与凝胶渗透色谱法、弗罗里硅土固相萃取柱以及多层硅胶柱/氧化铝柱相比,13X分子筛对土壤提取液的净化效果优于前两种净化方法,可以获得与多层硅胶/氧化铝柱相近的净化效果(53.0%~117.0%),而且操作更加简单,环境更加友好,分析成本大幅度下降。在此基础之上,建立了加速溶剂萃取-分子筛固相萃取,结合气相色谱-三重四极杆质谱法测定土壤中PCNs的分析方法。PCNs同族体的方法检出限为0.009~0.6 ng/g。采用基质加标法评价了本方法的精密度和准确度,CN-3、13、42、46、52、53、73、75在低、中、高加标水平下的平均加标回收率分别为70%~128%、71%~115%和61%~114%,测定结果的相对标准偏差分别为4.2%~23%、6.5%~31%和4.7%~22%,满足痕量分析的要求且平行性较好。从整个分析流程来看,13X分子筛有望成为新污染物净化的新型固相萃取吸附剂,并在土壤新污染物普查中发挥重要作用。