萘降解菌的筛选及其对多环芳烃的降解

从柴油污染土壤中筛选分离出一株萘降解菌N-3,进行了菌种鉴定及萘双加氧酶基因(nah)验证,并考察了该菌对不同种类多环芳烃(PAHs)的降解能力及降解过程中脱氢酶活性的变化。实验结果表明:该菌为铜绿假单胞菌(Pseudomonas aeruginosa),含有nah基因;当分别对液体培养基中质量浓度为50 mg/L的萘、菲、蒽、芘、芴降解84 h时,菌株N-3对萘、菲、蒽、芘、芴的降解率分别为28.81%,34.83%,36.65%,27.50%,23.47%。菌株N-3的脱氢酶活性与其对不同PAHs的降解率呈一定的正相关性。该菌不仅能有效降解萘,且对其他种类PAHs也有一定降解作用。     

多环芳烃污染土壤的微生物修复技术

对生物修复技术中的微生物进行了分类,并阐述了微生物生物降解土壤中多环芳烃（PAHs）的基本原理。在此基础上,分析了国内外微生物生物修复技术的发展概况,采用图示法重点综述了原位处理技术和非原位处理技术的工艺流程,并列举了相应的工程应用实例。     

火电厂排烟中颗粒物及多环芳烃的研究

对某火电厂电除尘器前后烟气中颗粒物的形貌、粒径分布及多环芳烃(PAHs)在颗粒物、烟气气相及原煤中的含量进行了研究.结果表明,颗粒物主要呈圆球形,主要成分为Al2O3和SiO2,除尘器前颗粒粒径主要分布在5～10 μm之间,其后以5 μm以下为主;电除尘器对大颗粒有较好的收尘效果,而对小于5 μm颗粒的收尘效果较差;低环PAHs在气相中的含量均高于颗粒物中的含量;电除尘器对PAHs的平均脱除率能达到89.74%,对4环和6环PAHs的脱除率高于90%.     

高压液相色谱法测定水中多环芳烃

本文讨论了用Seppak-C_(18)小柱(Waters.Co.)对水中痕量多环芳烃进行富集、洗脱的最佳实验条件,确定了用Zorbaxods柱分离PAH的色谱操作条件。应用紫外(250nm)和荧光(Ex/Em=295nm/427nm)检测器串联的检测系统,大大提高了PAH的检测下限。该方法用于实际水样的测定,其实验结果与用环巴烷萃取法测定结果基本相符。     

燃煤电厂锅炉烟道气中多环芳烃的测定

介绍采用过滤、冷凝、吸附剂吸附三级串联的采样装置采集锅炉烟道气中多环芳烃和用超声提取、浓缩器浓缩、高压液相色谱分离、紫外-萤光检测器串联检测的实验方法。此法简单易行，适合于现场应用。     

生物泥浆技术修复多环芳烃污染土壤研究进展

生物泥浆技术作为一种污染土壤生物修复技术,具有修复效率高、修复时间短及修复成本低等优点。本文介绍了生物泥浆修复设备的结构及修复工艺流程,例举了生物泥浆技术修复多环芳烃（PAHs）污染土壤的典型案例,探讨了生物泥浆技术修复PAHs污染土壤效果的主要影响因素：PAHs理化性质、PAHs污染浓度和污染时间、微生物、泥浆水土比、电子受体、传质过程等。展望了生物泥浆技术未来的发展方向：通过分子生物学工具监控、调节生物修复,促进泥浆内部微生物群落活动,有针对性地提高微生物对PAHs的修复能力。     

活性炭固定床吸附分离溶液中表面活性剂和多环芳烃

利用活性炭固定床吸附分离表面活性剂和多环芳烃(PAH)的混合溶液,选取了具代表性的表面活性剂(TX100)和PAH(菲(PHE)等)。实验结果表明,流量越低、活性炭填充量越多、表面活性剂浓度越高、PAH浓度越低,越有利于表面活性剂的回收和PAH的去除。定义了有效回收时间,该时间是指PAH穿透10%的时间与表面活性剂穿透90%的时间之差,该时间越长,越有利于表面活性剂的回收。采用BDST和Thomas模型对TX100和PHE进行了吸附模拟,效果均较好;BDST模型拟合结果表明,当活性炭对TX100的吸附接近饱和时仍对PHE有较强的吸附能力。活性炭固定床吸附分离法可节约运行成本0.06元/L。     

燃煤烟气中多环芳烃的富集技术

介绍了燃煤电厂烟气中排放的多环芳烃污染物的富集方法,比较了各种富集技术的特点与使用情况,分析了多环芳烃富集过程中的质量控制与质量保证措施,并探讨了富集采样中的若干注意事项.     

甲苯降解菌的分离、鉴定及其对甲苯的降解特性

从重庆钢铁集团焦化厂脱酚池车间污泥中分离纯化得到一株能以甲苯为惟一碳源和能源的革兰氏阴性菌。根据生理生化实验结果、菌落特征、菌体形态,初步鉴定为假单孢菌属。菌株的最佳生长条件为：pH7、温度35℃、加入量100mL培养基中加入60μL甲苯、接种量5．0％。考察了菌株对甲苯的降解特性,在甲苯质量浓度为150mg/L时,比降解速率达到0．211h^-1。     

表面活性剂在多环芳烃污染土壤修复中的应用

介绍了单一表面活性剂（非离子表面活性剂、生物表面活性剂）、阴-非离子混合表面活性剂对多环芳烃的增溶作用、增溶机理及无机离子对表面活性剂增溶能力的影响,综述了化学表面活性剂和生物表面活性剂在污染土壤生物修复中的应用。由于生物表面活性剂具有许多独特的优点,今后应加强生物表面活性剂的开发与应用研究。     

大气粉尘中常见多环芳烃类化合物的提取及含量测定

采用便携式PM2.5采样器和玻璃纤维滤膜对大气粉尘进行采样,以加压液体萃取、超声波辅助提取和微波辅助提取3种方法对多环芳烃类化合物进行提取,以超高效液相色谱和质谱联用方法进行测定。共检测出16种多环芳烃类化合物,分别为:萘、苊、苊烯、芴、菲、蒽、荧蒽、芘、苯并[a]蒽、■、苯并[b]荧蒽、苯并[k]荧蒽、苯并[a]芘、二苯并[a,h]蒽、茚并[1,2,3-c,d]芘和苯并[g,h,i]苝。3种提取方法均可有效提取大气粉尘中的多环芳烃类化合物,加压液体萃取法的提取效率最高、超声波辅助提取法次之、微波辅助提取法最低。超高效液相色谱和质谱连用方法可有效地分析大气粉尘中的多环芳烃类化合物,线性方程的相关系数不低于0.998 3,测定值的相对标准偏差不超过0.80%,检出限不高于0.27 ng/g。     

Sedimentary Record of Polycyclic Aromatic Hydrocarbons in the Gulf of Trieste (Northern Adriatic Sea)

To reconstruct a history of polycyclic aromatic hydrocarbon (PAH) pollution in the Gulf of Trieste, one of the largest urbanized areas in the Adriatic Sea, we analyzed three long sediment cores collected between 1996 and 1997. Concentrations of total PAHs, the sum of 16 PAH compounds and six of their methylated analogues, in all three cores show a decrease from 600–800 ng g⁻¹, at the surface, to levels below 250 ng g⁻¹ in deepest layers (down to 3 m). The same trend was shown with separate representative pyrogenic PAHs (pyrene, benzofluoranthene and phenanthrene). Using Hg as a recent geochronological tracer, we observe an increasing input of PAHs since the beginning of the 20th Century and, especially, after the Second World War coinciding with increasing industrialization and urbanization of the region. This correlation is supported by PAH ratios that are indication of combustion processes and represent a marker for anthropogenic inputs. No correlation exists between PAHs and black carbon within the core profiles, indicating two different fractions of the ‘black carbon continuum’.     

Spatial and Temporal Comparison of Polycyclic Aromatic Hydrocarbons and Spheroidal Carbonaceous Particles in Remote European Lakes

Spheroidal carbonaceous particles (SCP) and polycyclicaromatic hydrocarbons (PAH) have been measured in the dated sediment cores of 10 remote lakes distributed across Europe. The geographic trends were evaluated by examination of the superficial sediment fluxes and total sediment inventories. The highest levels of both markers were observed in the Eastern European lakes whereas the minimal values corresponded to the lake located in the Arctic. However, this SCP-PAH correlation was not observed after exclusion of the end member lakes from the series. The temporal trends of both pollutant markers are consistent with the history of pyrolytic emissions over Europe. However, the downcore SCP distributions are shorter than the PAH profiles in nearly all lakes. The differences are probably related to the different size particle fractions involved in the measurement of each marker, >5 and >1 m for SCP and PAH, respectively. Thus, the two proxies probably reflect pollution inputs from closer (SCP) and more distant sites (PAH).     

The Effect of Interaction Between White-rot Fungi and Indigenous Microorganisms on Degradation of Polycyclic Aromatic Hydrocarbons in Soil

White-rot fungi applied for soil bioremediation have to compete with indigenous soil microorganisms. The effect of competition on both indigenous soil microflora and white-rot fungi was evaluated with regard to degradation of polycyclic aromatic hydrocarbons (PAH) with different persistence in soil. Sterile and non-sterile soil was artificially contaminated with ¹⁴C-labeled PAH consisting of three (anthracene), four (pyrene, benz[a]anthracene) and five fused aromatic rings (benzo[a]pyrene, dibenz[a,h]anthracene). The two fungi tested,Dichomitus squalens and Pleurotus ostreatus, produced similar amounts of ligninolytic enzymes in soil, but PAH mineralization by P. ostreatus was significantly higher. Compared to the indigenous soil microflora, P.ostreatus mineralized 5-ring PAH to a larger extent, while the indigenous microflora was superior in mineralizing 3-ring and 4-ring PAH. In coculture the special capabilities of both soil microflora and P. ostreatus were partly restricted due to antagonistic interactions, but essentially preserved. Thus, soil inoculation with P. ostreatus significantly increased the mineralization of high-molecular-weight PAH, and at the same time reduced the mineralization of anthracene and pyrene. Regarding the mineralization of low-molecular-weight PAH, the stimulation of indigenous soil microorganisms by straw amendment was more efficient than application of white-rot fungi.     

混合表面活性剂-浊点萃取法测定沉积物中多环芳烃的含量

以混合型表面活性剂（十二烷基硫酸钠（SDS）和对叔辛基苯基聚己二醇醚（Triton X-114））为萃取剂,采用浊点萃取法萃取沉积物中的15种多环芳烃（PAHs）,并利用HPLC技术测定15种PAHs的含量。实验结果表明,当混合型表面活性剂的加入量 3％（w）、混合型表面活性剂中SDS含量 50%（φ）、Na2SO4含量 8％（w）、萃取温度 60 ℃、超声萃取时间 10 min 时,15种PAHs的线性关系良好,r=0.998 9~0.999 7,检出限0.4~8.2 μg/L,加标回收率71.22%~97.36%,相对标准偏差0.92%~4.36%（n=6）。     

Diurnal Profile of Particle-bound Polycyclic Aromatic Hydrocarbon (pPAH) Concentration in Urban Environment in Tokyo Metropolitan Area

Traffic emits particles under 1 m. The particles arethe most responsible to particle-bound polycyclic aromatichydrocarbon (pPAH) which can impact human health. To assessthem as health hazards, we monitored diurnal changes in theconcentration and distribution of pPAH near roads in Tokyo.The total pPAH concentration was determined using aphotoelectric aerosol sensor (PAS) which ionized PAH-adsorbingparticles. The total pPAH concentration was compared withchemical analyses by gas chromatography/mass spectrometry(GC/MS). Two sampling sessions, one in August and one inSeptember 2000, were done at three sampling sites at the Hongo Campus of the University of Tokyo. Monitoring was every two minutes for six consecutive days for the first session and for seven consecutive days for the second session.Correlation of the pPAH concentration with traffic flow andwith meteorological conditions were also assessed. The pPAHconcentration varied in the same manner on all days: it sharplyincreased in the early morning by a sudden burden of traffic, and it rapidly decreased during the daytime, probably owing tophotodegradation and/or dilution by rising in the mixingzone. The local wind field, and consequently thetransportation of pPAH from the road, were stronglyinfluenced by the configuration and location of thesurrounding buildings. The pPAH clearly changed in 1- and0.5 day cycles, particularly at the roadside.     

芳香烃清洁硝化催化剂

综述了国内外有关芳香烃硝化过程中替代硫酸的催化剂的研究进展;介绍了沸石类催化剂、粘土类催化剂、离子交换树脂催化剂、固载化液体酸催化剂、金属氧化物及金属盐催化剂、杂多酸催化剂以及固体超强酸催化剂的合成及催化效率与优缺点.     

Assessment of Bacterial Degradation of Aromatic Hydrocarbons in the Environment by Analysis of Stable Carbon Isotope Fractionation

¹³C/¹²C stable carbon isotope fractionation was used to assess biodegradation in contaminated aquifers with toluene as a model compound. Different strains of anaerobic bacteria (Thauera aromatica, Geobacter metallireducens, and the sulfate-reducing strain TRM1) showed consistent ¹³C/¹²C carbon isotope fractionation with fractionation factors between C = 1.0017 and 1.0018. In contrast, three cultures of aerobic organisms, using different mono- and dioxygenase enzyme systems to initiate toluene degradation, showed variable isotope fractionation factors of C = 1.0027 (Pseudomonasputida strain mt-2), C = 1.0011 (Ralstonia picketii), andC = 1.0004 (Pseudomonas putida strain F1). The great variability of isotope fractionation between different aerobic bacterial strains suggests that interpretation of isotope data in oxic habitats can only be qualitative. A soil column was run as a model system for contaminated aquifers with toluene as the carbon source and sulfate as the electron acceptor and samples were taken at different ports along the column. Microbial toluene degradation was calculated based on the ¹³C/¹²C isotope fractionation factors of the batch culture experiments together with the observed ¹³C/¹²C isotope shifts of the residual toluene fractions. The calculated percentage of biodegradation, B, correlated well with the decreasing toluene concentrations at the sampling ports and indicated the increasing extent of biodegradation along the column. The theoretical toluene concentrations as calculated based on the isotope values matched the measured concentrations at the different sampling ports indicating that the Rayleigh equation can be used to calculate biodegradation in quasi closed systems based on measured isotope shifts. A similar attempt was performed to assess toluene degradation in a contaminated, anoxic aquifer. A transect of groundwater wells was monitored along the main direction of the groundwater flow and revealed decreasing concentrations accompanied with an increase in the ¹³C/¹²C stable carbon isotope ratio of the residual toluene. Calculation of the extent of biodegradation based on the isotope values and laboratory derived isotope fractionation factors showed that the residual toluene was degraded to more than 99% by microbial activity. Calculation of the theoretical residual toluene concentrations based on the measured isotope values described the strongly decreasing concentrations along the plume. Other aromatic hydrocarbons like benzene and naphthalene which were analysed in the same course also showed decreasing concentrations along the groundwater flow path accompanied by increasing ¹³C values indicating biodegradation.