土壤中多氯代二恶英（PCDDs）的研究进展

介绍了国内外对土壤（尤其是城市污泥）中的多氯代二恶英（ＰＣＤＤｓ）的研究现状,包括：土壤中ＰＣＤＤｓ的来源、分布及迁移转化情况,其环境稳定性使污染的危害程度加重;ＰＣＤＤｓ在环境中的降解主要是光降解、微生物降解和化学降解。     

五氯酚及其钠盐中氯代二恶英类分析

采用ＨＰＬＣ和ＧＣ／ＭＳ的方法，对国产ＰＣＰ及其钠盐中的ＰＣＤＤｓ，ＰＣＤＦｓ进行了分析。测定了所有２，３，７，８－取代同系物。此外，还根据各ＣＤＤｓ，ＣＤＦｓ的毒性当量因于ＴＥＦｓ，计算了其毒性当量Ｉ－ＴＥＱｓ，分别为１４２，９２ｎｇ．ｇ＾－１。在前述基础上，仨算了由于ＰＣＰ及其钠盐的应用，引起的ＰＣＤＤｓ，ＰＣＤＦｓ环境输入。约为２４０ｋｇ／ａ。     

甲基对硫磷降解菌DLL-1的分离、鉴定及降解性研究

从长期施用甲基对硫磷的污染土壤中分离到一株能以甲基对硫磷为唯一碳源生长且能将其完全矿化的细菌 Ｄ Ｌ Ｌ－ １ ,经鉴定,为邻单胞菌（ Ｐｌｅｓｉｏｍｏｎａｓ ｓｐ ．） ．该菌株３ ｈ 内对５０ ｍｇ／ Ｌ甲基对硫磷的降解率为９３ ％ ,２４ｈ 内对５０ ｍｇ／ Ｌ甲基对硫磷的降解率为９５ ％ 以上．在葡萄糖铵盐培养基中, Ｄ Ｌ Ｌ１ 对甲基对硫磷的耐受浓度和降解速度均增大．降解曲线表明延滞期内,菌体依靠上一生长阶段分泌的酶类对甲基对硫磷进行降解,一旦菌体开始生长,则检测不到中间代谢产物对硝基苯酚的存在．生长情况和粗酶液试验均显示 Ｄ Ｌ１ 优良的降解性状     

土壤中4-溴苯胺降解动力学及其生态毒性追踪

秀谷隆是一种被广泛应用的取代脲类除草剂,其主要降解产物为４－溴苯胺（４－ＢＡ）,研究４－溴苯胺在不同土壤中的降解动力学规律,并用土壤环境指示动物弹尾目跳虫Ｃｏｌｌｅｍｂｏｌａ（Ｆｏｌｓｏｍｉａ ｃａｎｄｉｄａ）跟踪指示该化合物在进一步降解过程中的毒性,结果表明：４－溴苯胺在土壤中的降解行为可用一级反应动力学方程来较好地描述,其生态毒性明显高于母体化合物秀谷隆,该化合物在粘土中的残留量低于砂土,但毒     

石油降解菌的分离、鉴定及其降解能力的研究

从含油污泥中,筛选出能以２０ ＃ 机械润滑油为唯一碳源的３ 株石油降解菌菌株,经鉴定分别为动胶菌属（ Ｚｏｏｇｌｏｅａ ｓｐ ．） 、氮单胞菌属（ Ａｚｏｍｏｎａｓｓｐ ．） 和假单胞菌属（ Ｐｓｅｕｄｏｍｏｎａｓ ｓｐ ．） ．通过其降解能力的测试,以动胶菌 Ｄ２ 菌株对２０ ＃ 机油的降解能力最强：在含油浓度ρ＝ ５００ ～１ ５００ ｍｇ／ Ｌ 的摇瓶试验中,其除油率为２０ ．８ ％ ～２５ ％ ．利用动胶菌 Ｄ２ 菌株进行生物接触氧化法处理含油废水模拟试验,当入流浓度为１ ０００ ｍｇ／ Ｌ 时,除油率可达９０ ．５ ％ ～１００ ％ ．这一结果表明,动胶菌 Ｄ２ 菌株生物接触氧化法处理含油废水具有很好的应用前景     

多氯代二恶英在土壤表面的紫外光解研究

本文利用５００Ｗ中压汞灯研究了二恶英在干燥土壤中的紫外光解，根据光解结果计算了土壤中二恶英的降解深度，并分析了五氯代二恶英（ＰｅＣＤＤ）的光解产物，结果表明，二恶英在土表面发生了较快的光解反应，反应在２ｈ内基本完成，降解深度为０．０２７ｍｍ，对ＰｅＣＣＤ光解产物的分析结果显示，二恶英在土壤表面紫外光降解的主要途径为脱氯，而且脱氯优先发生在邻位下。     

多级硅胶／氧化名柱和GC／MS法测定焚烧炉固体排放物中的痕量PCBs

本文采用多段硅胶柱与碱性氧化铝柱提取纯化焚烧炉烟灰和炉灰中残留的多氯联苯（ＰＣＢｓ）。用１３Ｃ标记物测定了回收率，比较了固体样品的索氏提法和柱直接提取法，结果表明：柱提取方法是一种快速有效测定固体废物中ＰＣＢｓ的方法。应用ＨＲＧＣ／ＭＳ及ＧＣ／ＥＣＤ定量测定了焚烧炉固体排放物中ＰＣＢｓ总残留量及同系物含量。     

FeCI3存在时六六六热解生成PCDD／Fs的研究

在开管体系中，于２８０℃时研究了六六六无效体在Ｆｅ，ＦｅＣＩ３存在时的热解，以及影响热解产物中ＰＣＤＤ／Ｆｓ生成量的因素。ＰＣＤＤ／Ｆｓ的生成主要取决于ＦｅＣＩ３，而Ｆｅ的存在并不增加体系中ＰＣＤＤ／Ｆｓ的生成量。在封管体系中，研究结果表明，ＰＣＤＤ／Ｆｓ的生成量随ＦｅＣＩ３用量、反应时间和反应温度的增加而增加，但温度影响最大。实验还表明，氯苯、氯酚对ＰＣＤＤ／Ｆｓ的生成起决定作用。在２５０－２８     

不同菌源的微生物对邻苯二甲酸二甲酯生物降解性的比较

从处理石化厂废水的活性污泥中分离出１ 株邻苯二甲酸酯降解菌 Ｆ Ｓ１（ 荧光假单胞菌 Ｐｓｅｕｄｏｍｏｎａｓｆｌｕｏｒｅｓｃｅｎｓ Ｆ Ｓ１） ,从处理焦化厂废水的活性污泥中分离出２ 株邻苯二甲酸酯降解菌 Ｆ Ｓ２（ 铜绿假单胞菌 Ｐｓｅｕｄｏｍｏｎａｓａｅｒｕｇｉｎａｓａ Ｆ Ｓ２） 和 Ｆ Ｓ３（ 短杆菌 Ｂｒｅｖｉｂａｃｔｅｒｉｕｍ ｓｐ ． Ｆ Ｓ３） ． 研究了邻苯二甲酸酯降解菌 Ｆ Ｓ１ , Ｆ Ｓ２ 和 Ｆ Ｓ３ 对邻苯二甲酸二甲酯（ Ｄ Ｍ Ｐ） 的最适降解条件,比较了其降解特性． Ｆ Ｓ１ 、 Ｆ Ｓ２ 和 Ｆ Ｓ３ 最适酸度分别为ｐ Ｈ６ ．５ ～８ ．０ 、ｐ Ｈ７ ．０ ～８ ．０ 和ｐ Ｈ７ ．０ ～８ ．０ ,温度为２０ ～３５ ℃、１５ ～３５ ℃和１５ ～３５ ℃．邻苯二甲酸酯降解菌 Ｆ Ｓ１ 、 Ｆ Ｓ２ 和 Ｆ Ｓ３ 对邻苯二甲酸二甲酯的降解的半寿期： Ｆ Ｓ１ ＜ Ｆ Ｓ２ ＜ Ｆ Ｓ３ ,邻苯二甲酸酯降解菌 Ｆ Ｓ１ 是一株高效的邻苯二甲酸二甲酯降解菌     

蚯蚓驱动的滨海盐碱农田土壤中多环芳烃生物降解的机制研究

滨海盐碱地是中国重要的耕地资源,而人类活动等加重了滨海盐碱地的多环芳烃（PAHs）污染。微生物降解是去除土壤PAHs污染的重要手段。外源微生物的低环境适应性限制了其实际应用,诱导强化土著微生物原位修复具有重要意义。以较难降解的三环芳烃-蒽为多环芳烃代表,湛江市轻度滨海盐碱土为污染研究对象,赤子爱胜蚓（Eisenia foetida）为受试生物,设置4组处理（灭菌对照,SS;灭菌土壤加蚯蚓,SE;自然对照,OS;自然土壤加蚯蚓,OE）。比较不同时间段各处理土壤中蒽的降解效率、理化性质和培养结束时土壤微生物群落结构,明确蚯蚓对粤西地区滨海农田土壤蒽降解的强化效果、降解功能微生物种群和关键环境因子的贡献率。结果表明：蚯蚓能够影响滨海盐碱土壤中蒽的降解,并且加速其降解。在OS中蒽降解率为40.7%,而SS中蒽的降解率仅为17.7%。土壤中蒽的降解以生物降解为主（23.0%）,而不是非生物降解（17.7%）。OE处理的降解效率最高为62.1%,SE处理的降解效率为50.4%。蚯蚓强化非生物降解和肠道菌群作用共同的效果（32.7%）高于蚯蚓强化土著微生物降解的效果（21.4%）。同时,蚯蚓影响了土...     

Improvement of sampling and analytical methods for polychlorinated dibenzo‐p‐dioxins and dibenzofurans in environmental samples and its quantitative evaluation

Sampling of PCDDs/Fs in flue gas from a MSW incinerator was conducted using a modified apparatus of the 5 train method, which has been widely used for the sampling of PCDDs/Fs emission. In the atmosphere a high volume air sampler with special packings was used. Collection efficiencies of PCDDs/Fs were more than 98% for both samplers, using ¹³C₁₂—PCDD reference standard isomers. It was suggested that these sampling methods were adaptable for the measurements of PCDDs/Fs at sources and in the environment. To validate the applicability of existing methodologies on the PCDD/F determination, interlaboratory comparisons were undertaken. From high resolution GC/MS analysis, 2,3,7,8‐TCDD concentrations in reference ash samples were 0.052±0.013 ng/g as comparable results between the laboratories. In addition, the daily intakes of PCDDs/Fs for exposed persons in the MSW incineration facilities in Japan were estimated ranging of 0.053 to 0.28 pg/kg/day by the international toxic equivalent calculations.     

PCBs,PCDDs and PCDFs in soil samples from uncontrolled burning of waste electrical material for metal reclamation

PCDDs, PCDFs and PCBs have been analysed in soil samples where waste electrical equipment has been burned directly on the ground in three locations of Burgos (Spain). High levels of PCDDs, PCDFs and PCBs were detected in the centre of combustion sites. The results show PCB levels between 0.824 and 1.240 μg/g, and PCDDs and PCDFs levels between 8.73–36.37 ng/g and 12.79–50.95 ng/g. The I‐TEF values between 2.96–9.15 for dioxins and furans indicate that these soils are heavily polluted and may represent a risk for human and animal health.     

Levels and congener distributions of PCDDs,PCDFs and dioxin-like PCBs in environmental and human samples: a review

The term “dioxins” is often used in a confusing way. In toxicological considerations—and also in the present report—the term is used to designate the PCDDs, the PCDFs and the coplanar (“dioxin-like”) PCBs, since these classes of compounds show the same type of toxicity. Because of the large number of congeners, relevant individual congeners are assigned with a toxic equivalency factor (TEF) that relate their toxicity to that of tetrachlorodibenzo-p-dioxin (TCDD) (2,3,7,8-TCDD) and are to be evaluated as dioxins. Each concentration of an individual congener in a mixture is multiplied with its TEF, and the resulting TCDD equivalents are added up and expressed as WHO-endorsed toxic equivalents (WHO-TEQ). Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are mainly the by-products of industrial processes (such as metallurgical processing, bleaching of paper pulp, and the manufacturing of some herbicides and pesticides) but they can also result from natural processes like volcanic eruptions and forest fires. Waste incineration, particularly if combustion is incomplete, is among the largest contributors to the release of PCDDs and PCDFs into the environment. Due to their persistence, PCDDs, PCDFs and PCBs are part of the so-called persistent organic pollutants group of compounds that also include some chlorinated pesticides. Since they have a high lipophilicity and resist transformation, they bio-accumulate in animal and human adipose tissues. Consumption of food is considered as the major source of non-occupational human exposure to PCDD/Fs with foodstuffs from animal origin accounting for more than 90% of the human body burden. With meat, dairy, and fish products being the main contributors. The aim of the present review was to summarize experimental data regarding dioxin emissions from contaminated and uncontaminated biological and environmental samples, from the available literature. The information will be presented chronologically with respect to distribution in human milk, serum; food, water, air, soils and sediments.     

Study on polychlorinated dibenzo‐p‐dioxins and dibenzofurans in rivers and estuaries in Osaka Bay in Japan

In order to search the source of polychlorinated dibenzo‐p‐dioxins (PCDDs) and dibenzofurans (PCDFs) in blue mussel in Osaka bay, sediments from Osaka bay and from rivers running near an urban municipal incinerator were analysed for PCDDs, PCDFs and PCBs. The river and estuary sediments were all found to be contaminated with PCDDs at average levels of 9.8 and 12ppb on the dry basis, PCDFs of 7.8 and 5.1 ppb, and PCBs of 1600 and 1300ppb, respectively. The two sediments contained similar profiles of specific isomers and congeners of PCDDs and PCDFs with each other. In addition, there was observed positive close correlations between PCDD and PCDF levels in the two specimens as well as fly ash from urban municipal incinerators. These allow the conclusion that the main source of the two chemicals in Osaka bay is fly ash from waste incineration.     

Mechanistic aspects of the thermal formation of halogenated organic compounds including polychlorinated dibenzo‐p‐dioxins. Part V†: Hypotheses and summary

The hypotheses on the de novo syntheses of polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo‐p‐dioxins (PCDDs), based on known literature, are presented. Polychlorinated benzenes and polychlorinated phenols are probably key intermediates.

In the present article, hypotheses that may account for the presence of polychlorinated dibenzofurans (PCDFs) and dibenzo‐p‐dioxins (PCDDs) in the effluents from municipal and industrial incinerators are put forward. These hypotheses are based on the previously surveyed literature (Ref. 203–206) and experimental results on laboratory scale and thermodynamic calculations are considered. The interconnections of various reaction steps are speculative and no technological information was added to account for conditions in real incinerators. Conclusion of the discussions on the related subject matter, presented in the Parts I‐IV (Ref. 203–206), are also described in this paper.     

Prevention of dioxins de novo formation by ethanolamines

Two inhibitors, triethanolamine (TEA) and monoethanolamine (MEA), were tested for their ability to prevent the de novo formation of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) on sinter plant fly ash. The amounts of both PCDDs and PCDFs, formed by thermal treatment of the fly ash, decreased when inhibitors were added. Up to 90% reduction of the PCDD/Fs formation was reached when 2 wt % monoethanolamine was mixed with fly ash. The temperatures tested, 325 and 400 °C, did not affect the inhibition activity. However, a longer reaction time, 4 h instead of 2 h, gave higher percentages of PCDD/Fs reduction. The laboratory results show that ethanolamines reduce the dioxins formation on sinter plant fly ash under various conditions of temperature and reaction time. Moreover, factory tests performed in parallel at a sinter plant are in good agreement with the laboratory experiments, thus confirming that the use of ethanolamine inhibitors is an appropriate technique for the prevention of dioxins emissions from sintering processes. Electronic Publication     

Abstracts to forthcoming papers

Soil and sediments collected at a former chlor‐alkali plant in coastal Georgia (United States), revealed the presence of PCDF concentrations as great as 82.3 ng/g, dry wt. PCDF congener profile in soil was typical of “chlorine pattern”; with elevated proportions of OCDF and HpCDF. Concentrations of PCDFs declined gradually by 44‐fold at a distance of about 500 m along the contamination gradient. Of PCDDs/DFs, 2,3,7,8‐substituted PCDFs accounted for 94–98% of the TCDD‐like activity, which declined by 25‐fold, corresponding with the reduction of total PCDF concentrations. Concentrations of PCDDs in sediments were as great as 17 ng/g, with an elevated contribution from OCDD. The magnitude of decline in PCDD concentrations with distance from the source was less pronounced than that for PCDFs. PBDDs and PBDFs were not detected. Polybrominated biphenyl ether (PBBE) and monobromo‐heptachloro dibenzo‐p‐dioxins and dibenzofurans (PXDDs/DFs) were found, though, at low concentrations. Their spatial distribution was similar to those of PCDDs.     

Detailed analysis of PCBs and PCDD/Fs impurities in a dielectric oil sample （ASKAREL Nr 1740） from an imported transformer in China

Homolog and congener profiles of polychlori- nated biphenyls （PCBs）, polychlorinated dibenzo-p- dioxins （PCDDs） and polychlorinated dibenzofurans （PCDFs） in commercial PCBs formulations are useful information for the source appointment of PCBs contam- ination as well as the risk assessment caused by potential exposure. Dielectric oil （ASKAREL Nr 1740） in an imported transformer found in China was sampled and analyzed by isotope dilution technology using high resolution gas chromatography-high resolution mass spectrometry （HRGC/HRMS）. The detailed homolog and congener profiles of PCBs obtained were compared with those of known Aroclor formulations. High similarity in the homolog profile between the oil sample and Aroclor 1260was found, with the hexachlorinated and hepta- chlorinated biphenyls accounting for more than 80.2% of the total PCBs concentration. Severn indicator PCBs contribute about 30%, while 12 PCB congeners （i.e., # 153, #143, #168, #180, #149, #165, #138, #170, #190, #187, #174, #181） account for more than 50% of the total PCB concentrations. Total concentration ofPCDDs, PCDFs and dioxin-like PCBs （DL-PCBs） was found to be 740 ng TEQ/g, of which 620 ng TEQ/g came from DL-PCBs. The contribution of PCDDs to the total TEQ was neglectable. The concentration of PCDFs homologs follows the order of OCDF 〉 HxCDFs 〉 HpCDFs 〉 PeCDFs 〉 TeCDFs, which is in consistence with the previous study on Aroclor 1260. Three DL-PCBs congeners （i.e., #118, #156, #157） accounted for 77% of the total concentration of DL-PCBs, also they contribute 72% in the TEQ caused by DL-PCBs.     

六六六热解废渣中2,3,7,8—取代PCDDs和PCDFs的测定

采用ＨＰＬＣ和ＧＣ／ＭＳ法对六六六热解废渣中的ＰＣＤＤｓ和ＰＣＤＦｓ进行了测定，使用此种方法，于废渣中检出了所有２，３，７，８－取代的同系物。此外，还根据各ＣＤＤｓ，ＣＤＦｓ的毒性当量因子ＴＥＦｓ，计算了废渣的毒性当量ＴＥＱｓ，约为６１２－９２４μｇ／ｇ。分析表明，ＯＣＤＤ是含量最丰富的导构体，而１，２，３，４，６，７，８－ＨｐＣＤＤ，１，２，３，４，６，７，８－ＨｐＣＤＦ和１，２，３，４，７，８