复习课件环境科学与工程专业英语翻译.docx

第四单元阅读材料：

Reading Material : Analytical Technique and Methodology

第八单元：空气污染物的来源和类型

第八单元Reading Material : Type and Sources of Air Pollutants [ II J

阅读材料：空气污染物的类型和来源（Ⅱ）

What are PCBs?

什么是多氯联苯？

There are 209 possible chlorinated biphenyls, ranging in physical characteristics. 大概有209种氯化联苯，其物理性质不同。The mono-and dichloro biphenyls ( 27323-18-8), ( 25512-42-9) are colorless crystalline compounds that when burned in air give rise to soot and hydrogen chloride. 一氯联苯和二氯联苯（27323-18-8），（25512-42-9）是无色晶体的化合物，当它们在空气中燃烧会产生烟尘和氯化氢。The most important products are

tri­chlorobiphenyls,tetrachlorobiphenyls, pentachlorobiphenyls and/ or hexachlorobiphenyls. 最重要的产品是三­氯化联苯，四氯联苯，五氯联苯和/或六氯联苯。

Chlorinated biphenyls are soluble in many organic solvents and in water only in the ppm range. 多氯联苯可溶于有机溶剂和仅在水的百万分之一ppm（part per million）的范围内溶解。Although chemically stable (including to oxygen of the air) they can be hydrolyzed tooxybiphenyls under extreme conditions forming toxic polychlorodibenzofurans.氯化联苯易溶于在许多有机溶剂和水只有在的范围内的可溶性。虽然化学稳定性（包括空气中的氧气）但是在一定条件下，多氯联苯可水解氧化成二氧化苯极端条件下形成的有毒的多氯代苯并二噁英。

The PCB class of compounds received substantial attention and notoriety when in 1968, in Japan,accidental poisoning occurred by cooking rice in bran oil contaminated by PCBs.在1968年，多氯联苯类化合物受到实质性的的关注和得到臭名，日本用受到多氯联苯污染的米糠油做饭的意外中毒事件。Over 1000 patients suffered from various morbid symptoms. 超过1000例患者出现各种病态症状。A similar poisoning occurred in Taiwan in 1979. Causative agents were considered to be coconaminants of PCBs such as poly­chlorinated dibenzofurans that are secondarily formed during heating of PCBs congeners in commercial PCB mixtures and require a second look at PCB toxicity. 1979年台湾有一个类似的中毒事件。病原体被认为是如

多氯二苯并呋喃的多氯联苯，其次是PCBs多氯联苯同系物在商业PCB混合物在加热过程中形成的，需要第二次看看PCB的毒性。

PCB regulation多氯联苯的管理

Because of concerns regarding PCB' s health effects and evidence of presence and persistence in the environment further manufacture of the chemical was banned under The 1976 Toxic Substance Control Act. 由于担心多氯联苯对健康的影响和证明存在以及持续在环境中会进一步制造化学物质的，在1976年美国有毒物质控制法中被禁止了。PCB regulations provide deadlines for removal of most in-use capaci­tors and transformers containing PCBs · and limit time for storage for disposal to one year. 多氯联苯的管理提出最后期限为了最大去除使用电容器和变压器逗留的多氯联苯和限制储存一年就要处理。EPA has allowed continued use of PCBs in electrical transformers and capacitors when the agency did not pose unreasonable risk. 当经销产品不会产生过度的危险时，环境保护局允许继续使用含多氯联苯的电子电容器和变压器。Capacitors, except those in isolated areas should have been removed by October 1988, and transformers of a certain size in or near commercial buildings should be removed by October 1990. 电容器，除了那些分散地方的应该被移走在1988年10月之后，变压器的某一些型号和靠近商业建筑的应该被移走在1990年10月后。

EPA regulations require that PCBs taken out of service be disposed of either by specially designed high temperature incinerators needed to break high concentrations of PCBs to

harm­less components or by alternate destruction methods approved by the agency. Environmental Protection Agency 美国环保署，法规要求PCB服务多氯联苯或者处置的，通过特别设计的高温焚化炉需要打破高浓度的多氯联苯的无害组件或替代由该机构批准的销毁方法。Oils contami­nated with low concentrations (50-500ppm) may be disposed by high efficiency boilers. 低浓度（50〜500PPM）污染的油可以通过高效率的锅炉处理。

The limited number of incinerators approved for PCB incineration and the high cost of building additional incinerators have given incentive for alternate destruction methods. Alternate technologies must be capable of operating as effectively as EPA' s incineration effi­ciency. 批准用于焚烧多氯联苯的焚烧炉数量被限制和成本高且附有焚烧炉的建筑鼓励使用一一分解的方法。选择的技术的运转效率必须能够达到环境保护局的焚烧效率。

PCBs in electrical transformers

多氯联苯的电流体变压器

There were 304 million lb of PCBs used as electrical fluid in approximately 150000 askarel ( non-flammable electrical fluid) transformers in the United States. 在美国有304百万磅的多氯联苯被当做电流体使用，大约150000阿斯卡列（不易燃的电流体）变压器。About 70000 PCB trans­formers are in or near commercial buildings that are open to the public. 大约70000多氯联苯变压器建在或靠近对公众开放的商业建筑。About 40000 of these transformers are owned by electrical utilities. Approximately 15000 of these transformers are used in the food and feed industry. 大约40000这些变压器缺少电设施。大约15000这些变压器被使用在食品和饲料工业。Utilities and other industries must maintain or dispose of approximately 150000

askarel­type transformers that may develop leaks.公用事业等行业必须保持或处置约150000氯代联苯­型变压器可能出现的漏洞。Each year, an estimated 317 askarel-type trans­formers can be expected to leak. Each will lose about 5. 3 gal or 66 lb of PCBs. 公共设施和其他工业必

须维护或处理大约150000阿斯卡列型变压器可能产生的泄露，每一年，估计317阿斯卡列型变压器被暴露泄露，将损失5.3㎡/s或66磅多氯联苯。

Transformers classification变压器的分类