辽宁省部分城市空气中二(口恶)(口英)含量测定及结果分析

对辽宁省部分城市环境空气中二(口恶)(口英)类物质含量的测定结果表明,该地区环境空气中二(口恶)(口英)含量在0.07～1.0pg TEQ/m3之间.     

碱性及含硫化合物对十溴联苯醚热降解的影响

将十溴联苯醚（BDE-209）于400~600℃的温度范围内进行热降解,利用GC、GC/MS对产物种类及含量变化进行分析,讨论了温度、时间、碱性化合物和含硫化合物对BDE-209降解以及对溴代二噁英生成的影响.结果表明.温度和时间均是BDE-209热降解和生成溴代二噁英的重要影响因素;热降解40min时,450℃条件下溴代二噁英生成量最多;产物种类证实碱性化合物通过与BDE-209脱溴形成的HBr反应促进降解,且可抑制二噁英的生成;含硫化合物的添加同样促进BDE-209降解,抑制二噁英的形成,其详细的抑制机理有待进一步确定,BDE-209的降解反应有两种情况,即苯环上的脱溴反应和醚键的断裂反应.     

医疗废物集中焚烧处置技术的研究与应用

通过分析各种医疗废物处理技术的特点,指出医疗废物集中焚烧处置技术能够有效处理医疗废物、满足国家对医疗废物处理的要求,适宜在医疗废物集中处置项目中广泛应用。但该技术在实际工程应用中,还存在如处理成本高、设备使用寿命短和二英排放不易控制等问题,尚需进一步研究加以克服。     

焚烧源二噁英的排放对周边土壤和植被污染的研究进展

经济的飞速发展和城市化进程的加快,带来了严重的生活垃圾负荷问题。垃圾焚烧技术因其具有减容化、无害化和资源化的优点,成为当今国际社会生活垃圾处理的主要技术之一。然而由于人们对于垃圾焚烧源可能产生的二噁英污染问题缺乏一个全面的认识,使得垃圾焚烧厂的建立遭到了民众的强烈反对,成为影响社会和谐稳定的因素;因此,需要对垃圾焚烧源二噁英的排放对周边土壤和植被的污染状况进行综述,对于解决老百姓对于垃圾焚烧二噁英污染的争议有巨大的现实意义。对近年来国内外学者在相关方面的研究进行了详细地综述,结果发现：国内已开展的研究仅限于二噁英对焚烧厂周边土壤的污染调查,而对于焚烧源二噁英对植被及农作物的污染的研究数据非常匮乏;而国外学者已开展的垃圾焚烧厂周边土壤和植被中二噁英污染的调查研究只是停留在二噁英在土壤和植被中总浓度的研究基础上,而对于不同二噁英同族物在焚烧厂附近土壤和植被中的分布特征和蓄积规律方面的研究比较缺乏,尤其是在其他污染源如废弃物的露天燃烧、交通等协同作用下,垃圾焚烧对二噁英污染贡献率的研究比较少,对于垃圾焚烧厂二噁英污染的控制没有起到直观的指导作用。本文指出今后的研究应加强对二噁英在焚烧厂周边土壤和植被中分布特征和蓄积规律研究,这对于焚烧源二噁英的污染防治以及对已被二噁英污染的土壤和植被的生态修复具有重要的意义。     

土壤中的二恶英类物质污染及其污染源

为加强对二恶英类物质污染现状及污染途径的调查研究,为切实有效地控制其污染,并为制定相关法律、法规提供可靠的依据,综合国外土壤中二恶英类物质环境污染调查的文献资料及本实验室对北京地区的调查研究结果,介绍了全球土壤的二恶英类物质污染概况,指出土壤中二恶英类物质的主要污染源有城市固体垃圾焚烧、有机含氯化合物的合成和使用、汽车尾气排放等,不同的污染源,其二恶英类物质特征分布形态不同,通过对样品中二恶英类物质的异构体类型及其分布形态的分析,可以追溯污染的起源。对北京地区的初步研究显示北京地区土壤中二恶英类物质的污染水平相对较低,但这还不足以说明该地区的二恶英类物质整体污染水平,还需对污染疑似地区土壤进行全面系统的研究,同时对全国其他地区的调查研究也是急为迫切的。     

持久性有机污染物的主要特征和研究进展

概述了持久性有机污染物(POPs)在环境中的主要存在类型、生态行为特征、污染效应和对环境生物体的健康危害特性及我国在该领域的主要研究进展.重点介绍了二NFDA7英类化合物的生态毒性表示法、主要处置技术与相关的检测方法等研究进展.我国POPs相关的基础研究相对滞后,要履行好POPs公约,还面临诸多需要解决的现实问题.当前开展适合我国国情的POPs物质的环境调查监测、环境安全与健康毒理学研究并建立相关的环境控制基准和评估体系十分必要.      

我国二英污染水平和环境归趋模拟

运用Level Ⅲ逸度模型,研究了我国环境介质中二英的平均浓度水平和迁移规律. 比较不同尺度下的模拟结果表明,Level Ⅲ逸度模型可以应用于较大尺度的研究. 数据显示,虽然我国二英排放总量较大,但是环境介质中TEQ(指二英毒性当量质量浓度)平均值仍处于较低水平,大气中TEQ平均值仅为4.26～15.10 fg/m3,土壤中TEQ平均值为0.013 5～0.115 0 pg/g,沉积物中TEQ平均值为0.445～2.300 pg/g. 达到稳态时二英的外界输入影响较大,且主要的迁移过程是从大气到土壤.      

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.     

Metal binding capacity of soft acid,organic‐rich waters

Organic carbon from one stream and two ponds in South Carolina was fractionated into five nominal molecular diameter fractions by ultrafiltration. The concentrations associated with and binding capacity for Ca, Cd, Cu and Pb were determined for each fraction. The distribution of organic carbon among ultrafilter fractions varied from water to water, with the largest percentage occurring in the smaller fractions. Calcium was associated with each of the fractions isolated from each of the three waters, indicating Ca is bound to organics in all fractions, however, more than 99% of the Ca which passed the smallest ultrafilter was removed by cationic exchange resin. Each fraction bound more Ca than Cd, Cu or Pb except in a few cases where Pb binding was greater. All of the organic fractions had their Ca++ binding sites saturated. Calcium was not an effective competitive ion against Cd, Cu or Pb for organic binding sites. The total Cu binding capacity was less than that of Ca or Pb but similar to that of Cd. Naturally occurring organics bound more Pb than Cd or Cu but less than Ca. Saturation of Cu binding sites was less than 20% in most ultrafilter fractions except that with a nominal molecular weight of between 10,000 and 300,000 where the percent of saturation was as much as 60%. Approximately 50% of the Cu was removed onto anionic exchange resin in two waters while more than 90% was removed from water with a high organic content. Percent saturation of Cd and Pb binding sites ranged from 0.091% to 5.4% and 0.059% to 1.5%, respectively. All ions tested effectively competed with Cd, Cu or Pb for some but not all binding sites, indicating that organic binding sites were heterogeneous. A generalized order of metal‐organic stabilities based on competition for binding sites is Al>Cd>Pb>Cu>Ni = Mg=Zn = Mn>Ca. Both Cd+2 and Al+3 effectively out competed Pb++ and Cd and Pb out competed Cu for most organic binding sites.     

建设项目中常见的内分泌干扰物的污染和控制建议

建设项目常见排放的内分泌干扰物主要包括二噁英类、多氯联苯和多溴联苯、砷及重金属、双酚A、苯并[a]芘和氯乙烯等。生物质燃烧和掺烧污泥的锅炉废气中的二噁英、掺烧石油焦的锅炉废气中的苯并[a]芘和化工项目排放的双酚A等均存在执行标准缺失问题。电子类项目中的多氯联苯和多溴联苯、冶炼项目中的砷及重金属、化工类项目中的氯乙烯等也应加强全过程监管。建议研究建立优控清单,系统地提出相关控制政策,管理建设项目环境激素类的产生和排放。