纸废料中的二噁朊

<正> 近年来美国工业界及政府已经注意到二(口恶)朊对人类的影响。二(口恶)朊即2,3,7,8四氯二苯并-p-二(口恶)朊-(TCDD)[以前译为二氧蒽dioxin]。从美国纸浆及造纸工业分析结果有小量二(口恶)朊。另外纸产品亦有微量二(口恶)     

垃圾焚烧厂周围环境中2,3,7,8-TCDF的测定和分析

以某垃圾焚烧厂附近的大气样品和土壤样品为研究对象,采用同位素稀释高分辨气相色谱-高分辨质谱法(HRGC/MS)联用技术分析典型的二噁英类物质2,3,7,8-四氯代二苯并呋喃(2,3,7,8-TCDF)。结果表明,大气样品方法回收率为62%～134%,大气采样点中2,3,7,8-TCDF的毒性当量浓度为2. 02×10~(-6)～8. 57×10~(-6)ng I-TEQ/Nm~3,其中颗粒相浓度占比大于气相浓度。土壤样品方法回收率为82%～145%,土壤样品中2,3,7,8-TCDF的毒性当量浓度为0. 11～0. 42 ng I-TEQ/kgdm,可以达到相关标准要求。     

12种氯苯类化合物纯度定值色谱方法研究

对用于溶液标准物质制备的12种氯苯类纯品原料进行了高效液相色谱法(HPLC-DAD)和气相色谱法(GC-FID)两种纯度定值方法的研究。在优化的色谱条件下,甲醇基体混合溶液中的12个目标物组分包含一氯代苯、1,2-二氯苯、1,4-二氯苯、1,3-二氯苯、1,2,3-三氯苯、1,2,4-三氯苯、1,3,5-三氯苯、1,2,3,4-四氯苯、1,2,4,5-四氯苯、1,2,3,5-四氯苯、五氯苯、六氯苯均能良好分离。避免了氯苯类原料中存在的同分异构体及同系物杂质与主体成分没有良好分离而导致的对纯度定值结果的影响。     

五氯酚在飞灰表面低温反应生成二(口恶)英特性

在管式炉上研究了不同试验条件飞灰/五氯酚生成二(口恶)英的分布特性.采用色质联机(HRGC/LRMS)测定了PCP中以及生成产物中的二(口恶)英含量.结果表明,生成产物中的二(口恶)英主要以气态形式存在,总的二(口恶)英中以PCDDs为主,比例高于97%,PCDDs中主要同系物是六至八氯代PCDDs.分析了飞灰含量以及氧含量对二(口恶)英生成的影响,二(口恶)英生成量随着飞灰中含碳量的增加而增大,氧含量是控制二(口恶)英生成的关键因素,氧含量在6.7%时生成的二(口恶)英总量及毒性当量值最小.对试验中产生的二(口恶)英进行了质量平衡,为进一步研究垃圾焚烧过程中二(口恶)英排放以及分布特性打下基础.     

五氯酚在飞灰表面低温反应生成二口恶英特性

在管式炉上研究了不同试验条件飞灰/五氯酚生成二口恶英的分布特性.采用色质联机(HRGC/LRMS)测定了PCP中以及生成产物中的二口恶英含量.结果表明，生成产物中的二口恶英主要以气态形式存在，总的二口恶英中以PCDDs为主，比例高于97％，PCDDs中主要同系物是六至八氯代PCDDs.分析了飞灰含量以及氧含量对二口恶英生成的影响，二口恶英生成量随着飞灰中含碳量的增加而增大，氧含量是控制二口恶英生成的关键因素，氧含量在6.7％时生成的二口恶英总量及毒性当量值最小.对试验中产生的二口恶英进行了质量平衡，为进一步研究垃圾焚烧过程中二口恶英排放以及分布特性打下基础.     

多氯芳香族或杂环一、二、三腈基化合物的制备

本专利制得的化合物可分为下列几类:1.氯化芳腈——尤其是五氯苯甲腈、有三个异构体的四氯苯二腈、三氯三间腈、七氯1-氰化萘,七氯2-氰化萘和八氯4,4′-二氰二苯。2.氯化杂环腈——如氯化腈基吡嗪、氯化腈基嘧啶、氯化腈基1,3,5三嗪、氯化氰基吡啶(美国专利3,325,503)、四氯4-氰基吡啶。     

二(口恶)英类化合物多氯代二苯并呋喃色谱保留值与基团修饰指数的相关性

为了研究多氯代二苯并呋喃(PCDFs)的构效关系,采用基团修饰指数作为PCDFs的分子结构描述符,通过线性回归方法建立了色谱保留指数RI、相对保留时间RRT与分子结构描述符之间的定量关系模型,各样本总体模型的相关系数均在0.97以上,估算色谱保留指数RI的平均相对误差为1.09%.利用方程对另外一些二(口恶)英分子的气相色谱保留指数RI和相对保留时间RRT进行了预测,预测平均值和相同氯原子数的实验平均值较为吻合,预测能力优于文献.     

1-(1,4-苯并二口恶烷-2-甲酰)哌嗪的合成

1-(1,4-苯并二口恶烷-2-甲酰)哌嗪是合成α1受体阻滞剂多沙唑嗪的重要中间体之一.Koo J等首先报道以邻苯二酚为原料经与2,3-二溴丙烯酸乙酯环合得1,4-苯并二口恶烷-2-甲酸乙酯,经水解得1,4-苯并二口恶烷-2-羧酸,与亚硫酰氯反应得1,4-苯并二口恶烷-2-甲酰氯,然后再和哌嗪进行酰化反应制得1-(1,4-苯并二口恶烷-2-甲酰)哌嗪[1].Campbell等提出除以上的合成路线外,1,4-苯并二口恶烷-2-羧酸的另一条合成路线,也是以邻苯二酚为原料,和氯环氧丙烷反应得2-羟甲基-1,4-苯并二口恶烷,经高锰酸钾氧化得1,4-苯并二口恶烷-2-羧酸,最后经氯化、酰化而得1-(1,4-苯并二口恶烷-2-甲酰)哌嗪[2].合成过程中的氯化一步采用二氯亚砜为氯化剂,苯为反应溶剂,且中间体1,4-苯并二口恶烷-2-甲酰氯极不稳定,不适合工业化生产.本文在文献[1,2]的基础上研究出1-(1,4-苯并二口恶烷-2-甲酰)哌嗪新的合成方法,即以邻苯二酚为原料,与2,3-二溴丙烯酸甲酯环合,生成的1,4-苯并二口恶烷-2-甲酸甲酯与哌嗪进行取代反应.此方法反应步骤短,反应条件温和,收率高,适合于工业化生产,其反应式如下.     

1-(1,4-苯并二噁烷-2-甲酰)哌嗪的合成

1 - (1,4 -苯并二口恶烷 - 2 -甲酰 )哌嗪是合成α1受体阻滞剂多沙唑嗪的重要中间体之一。ＫｏｏＪ等首先报道以邻苯二酚为原料经与 2 ,3-二溴丙烯酸乙酯环合得 1,4 -苯并二口恶烷 - 2 -甲酸乙酯 ,经水解得 1,4 -苯并二口恶烷 - 2 -羧酸 ,与亚硫酰氯反应得 1,4 -苯并二口恶烷 - 2 -甲酰氯 ,然后再和哌嗪进行酰化反应制得 1- (1,4 -苯并二口恶烷 - 2 -甲酰 )哌嗪[1] 。Ｃａｍｐｂｅｌｌ等提出除以上的合成路线外 ,1,4 -苯并二口恶烷 - 2 -羧酸的另一条合成路线 ,也是以邻苯二酚为原料 ,和氯环氧丙烷反应得 2 -羟甲基 - 1,4 -苯并二口恶烷 ,经…     

我国首家二噁英和PCBs检测实验室获认证

我国首家同时具有二口恶英和多氯联苯(PCBs)检测能力的大连化物所现代分析中心日前通过中国实验室认可委员会评审认证.该中心在2 0 0 3年开展的对世界卫生组织的国际比对中获得良好的比对结果,目前已开展了国内16个单位和一家日本企业共6 0余种样品的检测,对推动我国二口恶英等     

Degradation of PCDD/Fs in MSWI fly ash using a microwave-assisted hydrothermal process

In this work, microwave treatment was introduced to a hydrothermal treatment process to degrade PCDD/Fs (Polychlorinated dibenzo-p-dioxins and dibenzofurans) in municipal solid waste incineration (MSWI) fly ash. Three process additives (NaOH, Na₂HPO₄, H₂O), temperatures (150℃, 185℃, 220℃) and reaction times (1 h, 2 h, 3 h) were investigated to identify their effect on the disposal of fly ash samples through orthogonal experiments. High-resolution gas chromatography-mass spectrometry (HRGC/MS) was applied to determine the PCDD/F concentrations in MSWI fly ash. The experimental results revealed that 83.7% of total PCDD/Fs was degraded. Reaction temperature was the most important factor for the degradation of the total PCDD/Fs. Both direct destruction and chlorination reactions (the chlorination degree of PCDFs increased) took part in the degradation of PCDD/Fs in fly ash, which was a new discovery. Several PCDD/F indexes determined by the concentration of indicative congeners were found to quantitatively characterize the dioxin toxicity of the fly ash. Furthermore, heavy metals in the fly ash sample were solidified using microwave-assisted hydrothermal treatment, which provided an experimental basis for the simultaneous disposal of dioxins and heavy metals. Thus, the microwave-assisted hydrothermal process should be considered for the future disposal of MSWI fly ash.     

大气悬浮颗粒物和植物树叶中二噁英分布特征的研究

采用同位素稀释、高分辨气相色谱/高分辨质谱(HRGC/HRMS)联用技术,分析了广州市某一地区两采样点大气悬浮颗粒物和大叶榕、龙眼树树叶中二噁英的含量。结果表明,两地点大气悬浮颗粒物中二噁英质量浓度(10.87 pg/Nm3和10.34 pg/Nm3)和毒性当量(0.119 pg/Nm3和0.121 pg/Nm3)接近,而大叶榕、龙眼树树叶中二噁英质量浓度分别为268.4 ng/kg.dry和972.5 ng/kg.dry,毒性当量为3.99 ng/kg.dry和15.11 ng/kg.dry。通过分析大气和树叶样品中17种有毒同系物的分布特征,可推断这两种植物树叶中的二噁英主要来源于大气干沉降。此外,龙眼、大叶榕树叶中六氯代以上的有毒PCDD/Fs质量分数较高,说明高氯代二噁英在树叶中较稳定,易累积到较高的水平。     

硫酸铵和尿素抑制飞灰合成二(口恶)英

二(口恶)英(PCDD/Fs)排放制约了当前焚烧技术在垃圾处置和资源化利用领域的应用和推广。研究了硫酸铵和尿素在不同温度下对垃圾焚烧飞灰合成PCDD/Fs的抑制能力。实验结果表明:高温下(650℃)硫酸铵和尿素对PCDD/Fs合成具有更高的抑制效率,但高温下飞灰合成PCDD/Fs量远低于低温下(350℃)的生成量;PCDD/Fs的降低量均主要来自于PCDFs的减少,并且低温下TeCDF减少量最大,而高温下减少最多的同系物为OCDF。由于实际烟道中,高温处投入的抑制剂会进入低温段继续产生抑制作用,所以仍需要更多的研究正确评价抑制剂的抑制效果和最优使用温度。     

Perspectives on the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans during municipal solid waste (MSW) incineration and other combustion processes

The pathways by which polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) are formed and the interactions between their aromatic precursors, in particular chlorophenols (ClPhs), and transition metal catalysts are discussed. A literature survey and data from pilot-scale combustion experiments allow conclusions to be drawn on the relations between ClPhs and PCDD/Fs in municipal waste incineration and other combustion processes. The results suggest that the ClPh pathway is among the most important for the formation of PCDD/Fs.     

Determination of the vapor pressures of select polychlorinated dibenzo-p-dioxins and dibenzofurans at 75-275 °C

Vapor pressures were determined for several polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) at 75-275 °C, extending the available literature data to more relevant temperature regions and providing the first experimental data for 2,3,7-trichlorodibenzo-p-dioxin (2,3,7-TriCD). A modification of the effusion technique, based upon controlling the diffusion of the target compound and subsequent high resolution gas chromatography/low resolution mass spectrometry (HRGC/LRMS) analysis, was proven comparable to other accepted methods for determining the vapor pressures of semi-volatile organic compounds (SVOCs). Vapor pressures for octachlorodibenzo-p-dioxin (OCDD) and octachlorodibenzofuran (OCDF) were in excellent agreement with those reported in literature. The application of the current method for the vapor pressure determinations of eight polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDDs/PCDFs) in the extended temperature range (up to 275 °C) is reported. The extension of the vapor pressures to such temperatures, unprecedented for the PCDDs/Fs, is important for vapor-particle partitioning modeling in regions relevant to PCDD/F formation and control. Estimates for the melting temperatures and enthalpies of sublimation and vaporization are also reported, the latter for which no experimentally determined values have been found in the literature. The use of the method to deliver reproducible, trace concentrations (ppt-ppb) of targets was applied to the calibration of the jet-REMPI/TOFMS as an online detector for low chlorinated PCDDs/Fs.     

医疗废物焚烧炉启炉过程二噁英排放特性

选择了位于华东地区的某医疗废物焚烧处置设施开展启炉过程与正常工况下烟气和飞灰的二噁英排放特性对比研究。数据显示, 启炉后期烟气中二噁英的浓度达到1.68 ng I-TEQ·m^-3, 在焚烧炉温度稳定以后12 h, 达到2.77 ng I-TEQ·m^-3, 飞灰中二噁英毒性当量水平也达到4.5 ng I-TEQ·g^-1。启炉过程中烟气中气相二噁英所占比例逐渐增加, 从平均占到50%增加到超过90%。启炉过程中烟气二噁英排放速率高于其正常达标时的排放水平, 最高值为58.1 mg I-TEQ·h^-1, 超过正常排放的40倍。一个启炉周期二噁英的排放总量达到0.785 mg I-TEQ, 达标正常工况下二噁英的年排放总量为8.4 mg I-TEQ, 按照平均每年3次启炉来计算, 启炉过程二噁英的排放量占到全年正常排放的28%。     

金属化合物催化多环芳烃合成二噁英的机理

为研究飞灰中金属化合物催化多环芳烃合成二噁英的机理,进行了不同催化剂和苊的燃烧试验,同时进行了X射线衍射试验(XRD)和热重试验(TGA)。根据试验结果分析得到：多环芳烃主要以de novo反应合成二噁英, PCDFs占主要成分;在无氯气氛下,CuCl₂绝大部分还原生成CuCl,金属氯化物主要通过金属配位体提供氯源;CuCl₂和FeCl₃对催化裂解氧化苊的作用相似;CuCl₂在150～200℃就可以和苊催化反应生成二噁英或氯代有机物。     

Simultaneous Removal of Heavy Metals and PCDD/Fs from Hospital Waste Incinerator Fly Ash by Flotation Assisted with Hydrochloric Acid

Hospital solid waste (HSW) incinerator fly ash was designated as a special controlled waste because of its high concentrations of toxic heavy metals, polychlorinated dibenzo-p-dioxins, and dibenzofurans (PCDD/Fs). Most of the PCDD/Fs along with carbon constituents including powder activated carbon and unburned carbon in fly ash could be removed by column flotation on the basis of their hydrophobicity. The feasibility of extracting heavy metals from fly ash by adding a little of hydrochloric acid to the slurry during the flotation process was examined in this paper. The results showed that the acidic pulp could contribute to the high extraction ratio of the heavy metals, but the performance of decarburization and removal of PCDD/Fs was inhibited at very low pH value. Given consideration to the removal of two toxic matter including PCDD/Fs and heavy metals in HSW incinerator fly ash, the appropriate pulp pH value should be controlled at about 5. After flotation, both PCDD/Fs and heavy metals in the tailings could simultaneously meet the permitted limits of a landfill site of municipal solid waste in China. It was suggested that flotation with the assistance of an appropriate amount of acid might be a potential technology for the treatment of HSW incinerator fly ash.     

SO2抑制二英从头合成的实验及其过程模拟

实验研究了不同温度下SO₂对二 英（PCDD/Fs）从头合成的抑制特点,运用HSC Chemistry 6.1软件对主要无机化学反应过程进行模拟,探究了SO₂的抑制机理。结果表明,SO₂对PCDD/Fs总浓度和I-TEQ浓度的抑制效果随温度的升高而增强。PCDD/Fs总浓度和I-TEQ浓度抑制率从200℃不足20%分别提高到300℃时的75.6%和77.3%及400℃时的89.2%和80.5%;SO₂的添加促进了PCDD/Fs尤其是PCDDs同系物分布的低氯代化。在从头合成的高温段和低温段,SO₂分别侧重抑制PCDFs和PCDDs。相平衡计算和Gibbs自由能计算表明,SO₂优先与催化剂CuCl₂反应生成无催化活性的CuSO₄,其次与氯源Cl₂反应,最终实现PCDD/Fs的生成抑制。模拟结果对现有硫基抑制机理进行了验证和补充,对高效、廉价抑制剂的开发及工程使用具有重要意义。