顺式-二苯乙烯类化合物合成方法研究进展

近年来,随着顺式-二苯乙烯类化合物各种生物活性的发现,顺式-二苯乙烯类化合物作为重要的天然产物引起人们的广泛的关注。本文概述了顺式-二苯乙烯类化合物的主要合成方法。     

能在温和条件下销毁二噁类的新催化剂

废物焚烧炉产生的飞灰通常都含有二英。这种飞灰一般须在1250～1450℃高温处理使飞灰熔化,并分解二英或是在N2氛围下450℃温度处理使二英脱氯。日本千代田公司已开发出一种已获专利的催化剂,此催化剂能在常压、常温下分解二英。由于正在申请专利,该公司不愿透露有...     

日开发快速分解二噁技术

日本国际创造化学研究所用物理和化学方法相结合 ,开发出分解二口恶口英的新技术 ,可在常温下 1ｍｉｎ内完全分解剧毒物质二口恶口英。该技术被命名为“混合ＳＲ法”(Ｓ和Ｒ分别代表 2名科研人员的名字 )。该技术还能分解多氯联苯、农药、氟树脂等有害物质 ,且不产生二氯化碳。日开发快速分解二噁技术     

新的二噁处理方法

焚烧废物会产生二口恶口英。它们存在于焚烧灰烬中 ,可能会污染土壤。常规的把二口恶口英经 30 0～ 5 0 0℃温度分解除去的做法既费时又费钱。欧洲专利 0 914877报道 ,日本栗田工业公司的新工艺能在较低温度下迅速分解二口恶口英。。研究人员只把胺和铵化合物加入到灰烬或土壤中 ,当加热到 15 0～ 2 0 0℃时 ,这些胺和铵化合物气体与二口恶口英中的氯气反应产生无毒的产物。据称 ,如果反应 2 0～ 40ｍｉｎ ,将获得足够高的分解新的二噁处理方法     

N-亚硝胺类化合物的定性分析

建立了一种新的对N-亚硝胺类化合物定性的方法,设置了两种不同的实验方法水浴分解法和紫外分解法,发现两种方法均能对N-亚硝胺类化合物进行定性,但是水浴分解法没有紫外分解法效果好。选用紫外分解法对市售的21种洗涤样品进行分析,其中13种样品检测到有N-亚硝胺的存在。实验方法简单,操作简便,能很好的对N-亚硝胺类化合物定性分析。     

交替三线性分解算法与HPLC—DAD相结合用于硝基苯类化合物的二阶校正分析

目岛对于利用交替三线性分解算法与HPLC—DAD相结合用于硝基苯类化合物的二阶校正进行分析的效果进行探讨。实验方法利用交替三线性分解算法与HPLC—DAD相结合分剐分辨2,4-二硝基氯苯以及3,5-二硝基苯甲酸体系,并对其进行测定。两种体系都属于未知干扰的光谱及色谱重叠比较严重的硝基苯类化合物。实验结果利用交替三丝性分解算法结合HPLC-DAD的方法来进行分析时,其不需预先选择因子数,只需要确定因子数比实际的组分数大就可得到正确结果,受干扰物质的影响极小。实验结论通过分析表明,利用交替三线性分解算法与HPLC—DAD相结合能有效用于硝基苯类化合物的二阶校正。     

酸性过硫酸盐氧化法测定海水中溶解总磷

实验研究在碱性和酸性条件下,过二硫酸钾高温氧化四种不同类型含磷标准化合物在海水中的回收率和影响回收率的因素。结果表明,在碱性条件下过二硫酸钾高温氧化可使海水中非聚磷类化合物完全回收,而聚磷类化合物回收率不高,延长消化时间聚磷类化合物的回收率有一定提高。除个别化合物外,各类含磷化合物在酸性条件下可被定量回收。依此,建立酸性过硫酸盐氧化法分解测定海水中溶解态总磷的方法。     

环境中剧毒物二噁英的成因、危害及治理技术

综述二口恶英的来源、成因和危害 ,讨论前人在治理二口恶英方面所采用的热技术和非热技术及其存在的局限性。二口恶英治理的热技术包括高温过燃烧技术、红外脱毒技术、等离子体高温分解技术、熔盐脱毒技术、超临界水氧化技术、原位玻璃化技术等 ;非热技术包括化学脱氯技术、紫外光解技术、溶剂萃取技术、吸附技术、生物降解技术、化学降解技术、γ射线分解技术、光催化氧化技术等。文中还简要分析当前研究工作所面临的问题     

1,3,4-■二唑类化合物的合成及生物活性研究进展

1,3,4-■二唑是一类重要的含氮五元芳香杂环类结构单元,可与多种药效团融合,产生不同的生物活性,因此引起了人们的关注,也显示了广泛的应用和发展前景,在医药和农药领域尤为突出。综述了国内外以酰肼环合法、Huisgen反应高效构建1,3,4-■二唑类化合物的方法,同时对1,3,4-■二唑类化合物在抗病毒、抗菌、抗肿瘤、除草、杀虫等方面的生物活性进行了介绍,并对各类化合物的构效关系进行总结,为进一步研究1,3,4-■二唑类化合物的设计合成及其生物活性提供参考和借鉴。     

二嚙英对纺织品的影响

二嚙英是一种毒性极大的持久性有机污染物，严重危害生态环境和人体健康，近日深为国际社会关注，但是对其了解甚少，本文概要介绍二嚙英及其对纺织品的影响。最近比利时等国相继发生饲料被二嚙英污染，导致畜禽类产品及乳制品中含有二嚙英事件，引起人们极大的关注。二嚙英（Ｄｉｏｘｉｎ）是一种含有二个氧原子的杂环，英（－ｉｎ）为六节无氮不饱和杂环的尾称〔１〕，一般有对二嚙英和间二嚙英，并以前者为主，它们的分子结构式分别为：ＯＣＨＣＨＯＣＣＨＨ　对二嚙英　　ＣＨ２ＣＨＣＨＯＣＯＨ２　间二嚙英二嚙英是这一类化合物的通称…     

催化氧化脱除垃圾焚烧烟气中二恶英类的研究

选择钒、钨等过渡金属作为催化剂的活性成分,二氧化钛为载体,偏钒酸铵,钨酸铵等作为活性成分之来源,浸渍法生产了二氧化钛载钒催化剂。并进行了以载钒型催化剂分解垃圾焚烧烟气中的二恶英类的工业侧流试验,在反应温度为240～320 ℃、气体空速为7 000～8 000 h－1的工艺条件下,二恶英类分解率可达95％～99%。     

FORMATION MECHANISMS AND CONTROL STRATEGIES FOR DIOXINS IN INCINERATION PROCESS OF MUNICIPAL SOLID WASTES

Dioxins, which are of the most toxic materials on the earth, are principal emitted from waste incineration process. The molecular structures, toxicity parameters, such as toxicity equivalency factor, tolerable daily intake and physic-chemical properties of dioxins are briefly summarized. Three formation mechanisms of dioxins in waste incineration process, namely as de novo synthesis, mechanisms involving small organic molecular as precursors and homogenous gas phase reaction mechanism are alto reviewed. The influencing factors for dioxins formation during waste incineration process are also discussed. Three major methods for reducing dioxins emission from waste incineration process are discussed based upon the formation mechanisms and influencing factors. A new waste incineration process with low dioxins emission and low hydrogen chloride corrosion has been proposed based on multi- stage unit operation principal according to formation mechanisms of dioxins and potential production location in waste incinerators.     

垃圾焚烧飞灰熔融过程二(口恶)英分解特性

引　言焚烧处理技术凭借其高效快捷和显著的减量效果在城市固体废弃物 (MSW )处理领域日益占有重要地位 .随着社会的进步和公众环保意识的逐渐提高 ,焚烧过程的二次污染尤其是二英的排放成为限制焚烧处理推广的瓶颈问题[1,2 ] .目前我国的垃圾焚烧过程排放二英限值为 1 0ng     

Kinetics of thermal decomposition of ammonium copper chromate

Kinetics of thermal decomposition of ammonium copper chromate has been studied in the temperature range 275–350dgC. The decomposition curves (fractional decomposition vs time) were found to be of complex shape showing an initial process of decomposition and a very short induction period followed by the acceleratory and decay periods. The initial process of decomposition could be expressed by the first order decomposition rate law and was found to be a true chemical decomposition process as evidenced by the high activation energy (E = 16.7 kcal gmol^?1). In case of the main reaction, the decomposition data could be fitted well graphically to the Mamples contracting cube, the Avrami—Erofeev and the Prout—Tomkins rate expressions based on nucleation and growth. However, statistical analysis led to the selection of the Prout—Tomkins expression as the best rate model for the decomposition.     

二恶英分解蜂窝催化剂的研制

以二氧化钛为载体,以五氧化二矾和氧化钨为活性组分,辅以多种助剂,挤制成型制备出蜂窝催化剂。所制的蜂窝催化剂轴向压碎强度≥100 N,磨耗≤3%,节距（4～7） mm,壁厚（1.0～1.2） mm,收缩率≤2%,容重(0.5～0.7) g·cm^-3,几何表面积≥500 m²·m^-3,催化活性≥90%。将该催化剂用于净化垃圾焚烧废气二恶英,具有系统压降小、催化活性高和使用寿命长等特点。     

Leachate treatment by the reverse osmosis system

The DT-Module system for landfill leachate treatment installed at Yachiyo Town in the Kanto District of Japan was put into service in April 1999. The system, which is equipped with a disc-tube type reverse osmosis (RO) membrane module called the DT-Module, has been operating satisfactorily for more than two and a half years, producing very-high-quality product water, after treating very-high-salinity water with high-scaling ions. On the other hand, in Japan, the dioxin problem has become increasingly severe, and development work for dioxin removal incorporated in leachate treatment has also been requested. The DT-Module system showed excellent performance in removing dioxins from leachate. For dioxins in sludge from the settling basin and dried salt from the concentrate of the RO system, successful destruction data were obtained by furnace system heating in an oxygen-deficient atmosphere. The removal rate of dioxins by the DT-Module system and the destruction rate by the furnace were both higher than 99.9%. By applying the DT-Module system together with the furnace system, an excellent leachate treatment and a complete dioxin removal and destruction system have become available for leachate from landfills depositing incineration residue-containing dioxins.     

Zur Pyrolyse von 3-Ethylpent-2-en – Ein weiterer Hinweis auf eine Homoallyl-Umlagerung

Pyrolysis of 3-Ethylpent-2-ene — a Further Evidence for a Homoallylic-Rearrangement The pyrolysis of 3-ethylpent-2-ene has been studied under conditions of steam cracking in the temperature range 600—700°C in a laboratory scale tubular reactor. The main products of decomposition were methane, 2-ethylbutadiene and isoprene. The majority of products obviously arose from H abstraction and radical addition, typical for radical chain reactions in olefins decomposition including phenomena resulting from allylic resonance. The formation of isoprene, however, could only be explained by a reaction network including a homoallylic rearrangement.     

Reductive alkylation of a phenanthrene—formaldehyde resin

A model insoluble oxygen-free phenanthrene—formaldehyde resin has been reductively alkylated by means of potassium—naphthalene in THF and subsequent treatment with alkyl halide. The extractability of the resultant alkylated products by benzene reaches 50% and depends on the size of the groups introduced. The polydispersity of the benzene-soluble portions and the presence of methyl groups in them indicate that decomposition processes are taking place at the methylene bridges as well. Mainly on the basis of n.m.r. analysis of the benzene-soluble fraction of a reductively trimethylsilylated resin, quantitative information about the silylation and decomposition processes was derived. The results obtained are of interest to the study of reductive alkylation of coals.     

飞灰粒径对二恶英降解效率的影响

低温热脱氯工艺是垃圾焚烧炉飞灰中二恶英分解的一种常见技术,一方面可以实现对大部分二恶英同系物地高效脱除,但是另一方面也容易产生额外的二恶英。为了克服该技术的不足,进一步提高降解效率,本文将低温热脱氯工艺与TiO2/MoS2复合催化剂光催化降解技术相结合,研究在两者共同作用下,飞灰粒径对二恶英降解效率的影响。     

Dioxine – Eine Aufgabe für die Umwelttechnik

Dioxins – Task for Environmental Engineering Two decades of the environmental history of dioxins, i.e. of PCCDs and PCDFs, are examined, with the main emphasis being placed on developments in Germany. After a brief consideration of the important, environmentally relevant properties of dioxins, interest is focussed on the course of the Seveso incident of 1976. The environmental effects of dioxins observed in Seveso received global publicity. In the following years our knowledge of the analysis and toxicology of this group of substances greatly improved and the production of dioxins in the aromatics sector of the chemical industry was drastically reduced. In the 1980s, discussions concentrated on the formation of dioxins in waste incineration. The results obtained during this period led to the present situation in which waste incineration is no longer a significant source of dioxin emission in Germany. The greatest known source of dioxins in Germany is in the metallurgical industry. By the year 2000 this dioxin source will also have been largely eliminated.