Air quality and particles Epidemiological(流行病学) evidence associates atmospheric particles with diseases and mortality Particles penetrate the lungs, blocking and irritating aIr passages. Particles themselves could exert toxic effects. ( toxic substances present in the particles [polycyclic Aromatic Hydrocarbons are examples of toxic substances in aerosols.]

Cloud albedo forcing: Cooling Shortwave Radiation The shortwave ays from the Sun are scattered in a cloud; many of the rays return to space. The resulting\cloud albedo forcing taken by itself

Good Ozone and Bad Ozone Stratospheric ozone protect lives on Earth from harmful effects of UV radiation. .Iropospheric ozone: Causing respiratory distress and eye irritation Destroying plants Producing cracks in rubber Ozone is a strong oxidant, reacts with molecules containing C=C double bonds, forming epoxides

Major inorganic gaseous pollutants Carbon monoxide(co) Sulfur dioxide (S02) Nitrogen Oxide(NO, NO2) NOX=NO+NO2 Ozone(03)

Water vapor in the air The volume of Water vapor is variable, depending on temperature, precipitation, rate of evaporation and other factors at a particular location The percentage of water vapor ranges from 0.1- 5%. Generally it is 1-3%(the 3rd most abundant constituents in the air)

The atmosphere The atmosphere is a thin blanket of gas that envelops the earth The gases that make up the atmosphere are held close to the earth by the pull of gravity With increasing distance from the earth's surface, the temperature, density, and composition of the atmosphere gradually change

《环境地球化学》为环境科学专业硕士硏究生的一门学位课,主要介绍化学元素和微 量物质在人类赖以生存的周围环境中的含量、分布特征和来源,生物一非生物复合系统中化 学物质(包括营养物质,主要是针对污染物)的生物地球化学循环的基本过程(包括迁移、 转化和保留等)与反应机制及其与人类健康的关系,揭示人为系统干扰下区域及全球环境系 统的变化规律,为资源合理开发利用,环境质量有效控制及人类生存、健康服务

一、烃类有机污染物的微生物降解 烃类的微生物降解,在解决碳氢化合物环境污染方面起着重要的作用,在环 境中烃类微生物降解以有氧氧化占绝对优势

目前用于环境样品检测的分析仪器主要有气相色谱一质谱联用仪 GC-MSλ高效液相色谱联用仪( HP LC-MS)及等离子发射光谱一质谱联用 仪(ICP-MS)等。其中气相色谱一质谱联用仪(GC-MS)高效液相色谱联用 仪(HPLC-MS)主要用于检测环境样品中的有机污染物,而等离子发射光谱 质谱联用仪(ICP-MS)是检测环境样品中无机污染物的最好手段

一、液一固萃取(LSE)和液一液萃取(LLE) LSE和LLE一直是环境样品(固体或水)最为广泛应用的样品前处理方法如索 氏提取和溶剂萃取兼有富集和排除基体干扰的效果过去美国EPA500,600,800 系列方法大都采用这个方案其缺点是要耗用较大量的有机溶剂(数百ml),并易 引入新的干扰(溶剂中的杂质等),还需要费时的浓缩步骤并易导致被测物的损 失