化学氧化法氧化多环芳烃的研究进展

概述了近年来化学试剂氧化多环芳烃的研究情况,对萘、蒽、菲和芘的化学氧化法进行文献调研,分类综述了过氧化叔丁醇、双氧水、氧气及高价金属盐等氧化剂氧化多环芳烃的方法工艺.分别通过介绍不同氧化剂下的反应温度、反应时间、反应溶剂等.目前前3种氧化剂在萘、蒽、菲的氧化均有报道,而芘的氧化报道及应用较少.通过概述目前多环芳烃氧化的...     

芳烃催化加氢反应机理的研究进展

对萘、菲、蒽及芘根据不同计算方法所得的反应活性位进行总结,对苯在金属表面的催化加氢机理-芳烃交换机理进行概括,对菲在MoS₂/Al₂O₃催化剂表面生成二氢菲的基元反应步骤和在Ni-MoS₂/Al₂O₃催化剂表面加氢生成四氢菲的过程进行总结,还给出了蒽的催化加氢反应网络图,分析了在不同催化条件下蒽是否有中环断裂情况的发生,给出了芘在RaneyNickel（W-7）催化剂表面生成二氢芘、四氢芘和六氢芘的催化加氢机理反应图,以及根据能量最低理论,判断芘发生加氢反应的优先位置情况,分别计算了芘加氢生成二氢芘、四氢芘、六氢芘和十氢芘可能存在的加氢路径。并总结了蒽、菲等多环芳烃发生催化加氢反应的规律。加深对多环芳烃催化加氢机理的研究将更好地指导重质油轻质化的进行,因此对多环芳烃催化加氢机理的研究具有重要意义。     

金属离子对多环芳烃酶促降解的影响作用

采用超声波细胞破碎仪破碎获得胞内酶、紫外分光光度法测定多环芳烃含量的方法研究了黄杆菌FCN2产生的胞内酶对多环芳烃蒽、菲、芘的酶促降解作用并对影响酶促降解的主要条件(pH、温度、金属离子的激活作用)进行了优化.研究结果表明:(1)对影响多环芳烃酶促降解的条件进行了优化.当pH为6、温度为32℃时,胞内酶粗酶液对多环芳烃蒽、菲、芘的降解效果最好.(2)在pH为6、最佳温度为32℃时,研究了Ca2 、Mg2 、Mn2 、Fe3 、Fe2 ,Cu2 6种金属离子对胞内酶粗酶液降解活性的影响作用.研究结果表明,Ca2 、Cu2 两种金属离子对蒽、菲、芘的酶促降解都可起到激活作用.Ca2 对胞内酶酶促降解不同底物的激活作用最为明显;当向体系中加入的Ca2 矿为0.5mmol·L-1时,蒽、菲、芘的去除率可分别提高为不加金属离子时的1.34倍,1.59倍、1.84倍.(3)通过测定米氏常数发现,当不加金属离子时,以蒽、菲、芘为底物时粗酶液的米氏常数值分别为2.69×10-4、428x10-4、3.56×10-4 mol·L-1;加入0.5 mmol·L-1 Ca2 矿时的米氏常数值分别为1.54×10-4、3.58×10-4、2.46×10-mol·L-1,说明金属离子的加入增大了粗酶液与底物的亲和力,.因此使得加入金属离子时蒽、菲、芘的去除率显著提高.     

高效液相色谱-荧光检测法测定贝类中15种多环芳烃

建立了高效液相色谱-程序荧光检测法同时测定贝类中15种多环芳烃的方法。通过液相色谱柱、荧光激发和发射波长等条件的优化,实现15种多环芳烃组分基线完全分离和荧光高灵敏度检测。在优化的实验条件下,检测的15种多环芳烃中萘、苊和芴的检出限为0.5μg/kg,苯并[b]荧蒽、二苯并[a,h]蒽和苯并[g,h,i]苝的检出限为2.0μg/kg,其余化合物的检出限为1.0μg/kg;在检测的15种多环芳烃中,菲、蒽、芘、苯并[a]蒽、崫、苯并[a]芘、茚并[1,2,3-cd]芘在0.001~0.5 mg/L浓度范围,其余化合物在0.002~1.0 mg/L浓度范围,呈良好的线性相关,相关系数r0.995;当样品加标水平分别为2、10、100μg/kg时,回收率在71.1%~98.4%,RSD10%。该检测方法重现性高,检测灵敏度和准确度均满足分析要求。     

负载多壁碳纳米管SPME涂层制备及其性能

结合多壁碳纳米管优异的吸附性能,采用溶胶-凝胶法制备了负载多壁碳纳米管的固相微萃取(SPME)涂层,对16种多环芳烃(PAHs)标准化合物进行了萃取实验。结果表明:所制备的负载多壁碳纳米管的SPME涂层萃取性能优于商用PDMS涂层,特别是能有效提高对多环芳烃的萃取性能;对16种PAHs的检出限在0.21～9.86μg/L;除苯并(b)荧蒽外,在0～2500μg/L线性范围内,线性关系良好,相关系数均在0.9502～0.9999;5次平行样测定的相对标准偏差2.9%～14.3%。将该涂层应用于煤矿矿区地下水中多环芳烃类物质的检测,成功检测出了菲、蒽、荧蒽、芘、苣、苯并(a)芘等物质。     

超声提取高效液相色谱法测定大气可吸入颗粒物PM10中的四种多环芳烃

建立了以甲醇-水为流动相,高效液相色谱法同时测定大气可吸入颗粒物PM10中四种多环芳烃化合物的方法。方法用中流量TH-16A四通道采样器,石英纤维滤膜采集大气颗粒物样品,以甲醇为溶剂,超声波提取样品;用甲醇-水作流动相进行高效液相色谱分离,荧光检测器检测。采用优化的分离和测定条件对四种多环芳烃化合物苯并(b)荧蒽、苯并(k)荧蒽、苯并(a)芘、苯并[ghi]芘进行加标回收率和精密度实验,回收率范围为86%~93%,相对标准偏差分别为2.0%~6.2%。     

超高效液相-荧光检测器法测定柴油中多环芳烃

建立了采用超高效色谱(UPLC)-荧光检测器法测定柴油中10种常见的多环芳烃含量的方法。这10种常见的多环芳烃为萘、苊、二氢苊、芴、菲、蒽、荧蒽、芘、苯并[a]蒽、艹屈、苯并[b]荧蒽、苯并[k]荧蒽、苯并[a]芘和苯并[g,h,i]芘。样品经过固相萃取后用甲醇溶解,采用Acquity UPLC BEH Phenyl C18柱(100 mm×2.1 mm,1.7μm)分离,乙腈-水为流动相进行梯度洗脱,采用荧光检测器检测,并用外标法进行定量分析。结果表明,在一定质量浓度范围内,峰面积与质量浓度的线性关系良好,用标准加入法进行回收率实验,对方法的准确度进行考察,相对标准偏差为0.56%~8.76%,加标回收率为100.04%~115.04%。与其他检测柴油中多环芳烃方法比较,该方法简单,分离效果好,快速及准确。     

橡胶制品中多环芳烃的测定标准介绍

多环芳烃(PAHs)是分子中含有多个苯环的碳氢化合物,包括萘、蒽、菲、芘等150多种多环化学结构式的总称。多环芳烃因为具有生物难降解性和累积性,是一类化学致癌物质和环境污染物。随着欧洲议会和欧洲理事会第2005/69/EC号指令的实施,很多欧洲国家出于安全考虑,对产品中的多环芳烃开始进行限制。在橡胶制品的生产过程中,由于使用了含有多环芳烃的添加油和其他的化学物质,导致产品中不可避免含有多环芳烃化合物。     

微柱萃取与液相色谱联用测定废水中痕量多环芳烃

微柱萃取具有体型小、操作简便、耗时短等优点。建立C18微柱萃取与高效液相色谱(HPLC)联用的分析方法,测定环境水中痕量多环芳烃(萘、苊、芴、菲、蒽、荧蒽和芘)。研究结果表明,在最佳条件下,萘的线性范围为10～200μg/L,芴和菲的线性范围为5～200μg/L,苊、蒽、荧蒽和芘的线性范围为1～200μg/L,线性相关系数(R2)均≥0.9907。检出限为0.11～2.00μg/L,检测限为0.37～6.66μg/L。该法用于环境废水中多环芳烃残留测定,加标回收率分别为85.3%～120.5%和83.5%～117.6%。     

橡胶制品中多环芳烃的测定标准介绍

多环芳烃( PAHs)是分子中含有多个苯环的碳氢化合物,包括萘、蒽、菲、芘等150多种多环化学结构式的总称.多环芳烃因为具有生物难降解性和累积性,是一类化学致癌物质和环境污染物.随着欧洲议会和欧洲理事会第2005/69/EC号指令的实施,很多欧洲国家出于安全考虑,对产品中的多环芳烃开始进行限制.在橡胶制品的生产过程中,由于使用了含有多环芳烃的添加油和其他的化学物质,导致产品中不可避免含有多环芳烃化合物.     

Removal of polycyclic aromatic hydrocarbons from contaminated soil in a two-phase partitioning bioreactor

A two-phase partitioning bioreactor was employed to remediate soil contaminated by a mixture of polycyclic aromatic hydrocarbons consisting of phenanthrene, anthracene, and pyrene. In this study, the transfer of three PAHs into the water-immiscible liquid phase (silicone oil or paraffine oil) from the soil was investigated during the first 24 h. And then, phenanthrene and anthracene were degraded by approximately 90% and 80%, respectively, compared with initial concentration in soil, but pyrene was not degraded during seven days of operation period. In addition, the feasibility of a soil slurry sequencing batch reactor system in terms of continuously operating a two-phase partitioning bioreactor was investigated. Phenanthrene and anthracene were degraded semi-continuously and repeatedly during two operating cycles. Pyrene was still not degraded and was just transferred into the water-immiscible liquid phase considering its solubility.     

Oxidation of Polycyclic Aromatic Hydrocarbons using Partially Purified Laccase from Residual Compost of Agaricus bisporus

Laccase partially purified from residual compost of Agaricus bisporus by an aqueous two‐phase system (Lac ATPS) was used in degrading polycyclic aromatic hydrocarbons: fluorene (Flu), phenanthrene (Phe), anthracene (Ant), benzo[a]pyrene (BaP), and benzo[a]anthracene (BaA). The capacity of the enzyme to oxidize polyaromatic compounds was compared to that of the crude laccase extract (CE). After treatment of 72 h, Lac ATPS and CE were not capable of oxidizing Flu and Phe, while Ant, BaP, and BaA were oxidized, resulting in percentages of oxidation of 11.2 ± 1, 26 ± 2, and 11.7 ± 4 % with CE, respectively. When Lac ATPS was used, the following percentages of oxidation were obtained: 11.4 ± 3 % for Ant, 34 ± 0.1 % for BaP, and 13.6 ± 2 % for BaA. The results reported here demonstrate the potential application of Lac ATPS for the oxidation of polycyclic aromatic hydrocarbons.     

Solubilities of solids in supercritical fluids-I. New quasistatic experimental method for polycyclic aromatic hydrocarbons (PAHs) + pure fluids

A new quasistatic technique is presented to measure the solubilities of polycyclic aromatic hydrocarbons (PAHs) and other solids in supercritical fluids (SCFs). This technique eliminates potential clogging during expansion of the SCF solutions, a problem inherent with most dynamic SFE units. The pressure inside the equilibrium cell is dropped very slowly in a quasistatic mode by sampling the saturated SCF solutions at low flow rates (1–5 standard ml min⁻¹). The technique is shown to be accurate and extensive data can be obtained in a relatively quick manner. In addition, this technique may be readily used in conjunction with basically any analytical method.After proving the accuracy of the new method, solubility measurements of anthracene, phenanthrene, pyrene, and perylene in supercritical carbon dioxide and ethane have been made at 313, 323 and 333K and pressure range of 100–350 bar. The simulateneous solubilities of anthracene, phenanthrene and pyrene in mixtures were also measured at the above three temperatures and over the same pressure range.     

PAH Metabolism in Cultured Mammalian Lung Epithelial Cells

In vitro cultures of mammalian cells have an advantage over animal experiments in that human cells can be directly compared with various other mammalian cells. In this study we compared the metabolism of several polycyclic aromatic hydrocarbons (PAH) (benzo[a]pyrene, chrysene, pyrene, phenanthrene, benz[a]anthracene) in epithelial cells from hamster, rat and human lung.

The cells investigated in our system yielded more or less qualitatively similar metabolic profiles for all PAH mentioned above except benz[a]anthracene in the three species. Additionally, species-specific differences were prominent between human and rodent cells with regard to the ratio of phase I and phase II metabolites.

Indications have been obtained that monooxygenase induction is required in fetal cells prior to metabolic conversion of those PAH which lack an inductive potential for CYP450.     

Interference of Soil Contaminants with Laccase Activity During the Transformation of Complex Mixtures of Polycyclic Aromatic Hydrocarbons in Liquid Media

The biotransformation of 16 polycyclic aromatic hydrocarbons (PAHs) in mixture was investigated in reactors in the presence of purified laccases of the fungus Pycnoporus cinnabarinus, ABTS as a redox mediator, 25% acetonitrile, and Tween 20. Several hydrocarbons from a synthetic mixture, such as anthracene and benzo[ a ]pyrene, were converted up to 80% into quinones, whereas others also belonging to three- and five-ring chemicals were less transformed. Chrysene and benzo[ k ]fluoranthene were not oxidized by the laccase mediator system. Moreover, hydrocarbons extracted from an industrial soil were all recalcitrant to enzymatic attack. This lack of reactivity of the laccases toward the hydrocarbons could be due to the presence of interfering compounds coextracted from the soil, such as metals.     

The Effect of Polycyclic Aromatic Hydrocarbons on the Structure of Organotrophic Bacteria and Dehydrogenase Activity in Soil

The objective of this article was to determine the structure of microbial communities and the activity of dehydrogenases in soil samples contaminated with four polycyclic aromatic hydrocarbons (PAHs), i.e., naphthalene, phenanthrene, anthracene, and pyrene, in the amount of 0, 1000, 2000, and 4000 mg kg^?1soil DM. Organic substances—cellulose, sucrose, and compost—were added to the samples in the amount of 0 and 9 g kg^?1soil DM. The experiment was performed in a laboratory on samples of loamy sand. Indices of colony development (CD) and eco-physiological diversity (EP) of organotrophic bacteria, soil resistance (RS), and soil resilience (RL) were calculated. Soil contamination with PAHs differentiated the structure of organotrophic bacteria, and the lowest CD and EP values were noted in soil samples containing pyrene. PAHs inhibited the activity of dehydrogenases, and pyrene exerted the most inhibitory effect on enzyme activity. Dehydrogenase activity was determined mainly by the applied PAH dose, the date of analysis and the type of organic substance added to soil. Low RL values indicate that exposure to PAHs induces long-term changes in dehydrogenase activity.     

Contamination of Soil by Polycyclic Aromatic Hydrocarbons in Some Urban Areas

The contamination by 16 polycyclic aromatic hydrocarbons (PAHs) in surface soils, sampled at a 0-5 cm depth in the urban areas of Tallinn, Helsinki, Vilnius, Chicago, London is reported. All samples were analyzed using the same protocol. The median concentrations ( w g/kg) were found to be 117, 539, 127, 3,263, 1,728 for pyrene; 62, 236, 43, 1,634, 1,652 for benzo[ a ]pyrene; 86, 304, 92, 2,295, 2,068 for benzo[ a ]pyrene toxic equivalents, calculated using the benzo[ a ]pyrene toxic equivalency factors; 467, 1,471, 392, 8,981, 6,837 for a total of seven probable human carcinogenic PAHs: benzo[ a ]anthracene, chrysene, benzo[ b ]fluoranthene, benzo[ k ]fluoranthene, benzo[ a ]pyrene, dibenz[ ah ]anthracene, indeno[1,2,3- cd ]pyrene; 911, 2,941, 672, 16,183, 13,718 for the total of 16 PAHs, recommended by the U.S. Environmental Protection Agency: naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[ a ]anthracene, chrysene, benzo[ b ]fluoranthene, benzo[ k ]fluoranthene, benzo[ a ]pyrene, dibenz[ ah ]anthracene, benzo[ ghi ]perylene, indeno[1,2,3- cd ]pyrene in Tallinn ( n = 3), Helsinki ( n = 3), Vilnius ( n = 15), Chicago ( n = 4), London ( n = 3), respectively. The size of the population is a statistically significant factor in urban soil contamination by high-molecular-mass PAHs.     

Photodegradation of Selected Aromatic Constituents of Creosote in Organic Solvents

Polycyclic aromatic hydrocarbons (PAHs), naphthalene, phenanthrene, anthracene, and pyrene were irradiated in acetonitrile (CH₃CN) and in dichloromethane (CH₂Cl₂) on individual PAH compounds and in the presence of other compounds. The observed photodegradation of PAHs was dependent on the structure of the compound. Anthracene and pyrene were the most photoreactive in dichloromethane: with total degradation after 0.5 h irradiation for anthracene and 1.5 h for pyrene. The decomposition of PAHs was faster in dichloromethane than in acetonitrile.     

有机硅表面活性剂对水体中多环芳烃的浊点萃取研究

Cloud point extraction （CPE） processes with two silicone surfactants, Dow Coming DC-190 and DC-193, were studied as preconcentration and treatment for the water polluted by three trace polycyclic aromatic hydrocarbons （PAHs）： anthracene, phenanthrene and pyrene. For all cases, the volumes of surfactant-rich phase obtained by two silicone surfactants were very small, i.e. a lower water content in the surfactant-rich phase was obtained. For example, less than 3% of the initial solution was obtained in a 1% （by mass） surfactant solution, which was much smaller than that of TX-114 in the same surfactant concentration. And TX-114 is known as a high compact surfactant-rich phase among most nonionic surfactants, thus the comparison showed that an excellent enrichment was ensured in the analysis application by the CPE process with the silicone surfactants, and the lower water content obtained in the surfactant-rich phase is also important in the large scale water treatment. The influences of additives and phase separation methodology on the recovery of PAHs were discussed. Comparing with DC-193, DC-190 has a lower cloud point and a higher recovery （near 100%） of all the three PAHs in same surfactant concentration, which was required for application as a preconcentration process prior to HPLC system. However the DC-190 solution is hard to be phase separated only by heating, whereas DC-193 has a relative higher phase separating speed by heating, but a high cloud point （around 360K） limits its application. Due to the phase separation by heating is the only method of CPE suitable to the large scale water treatment, the mixtures of two silicone surfacrants solutions were investigated in this study. A solution containing 1% of mixed DC-190 and DC-193 （in the ratio of 90 ： 10） removed anthracene, phenanthrene and pyrene near 100% with a relative low cloud point and quick phase separating speed.