大气颗粒物和降水化学特征的相互关系  

Relationship Between Atmospheric Particles and Rain Water Chemistry Character

作　　者：霍铭群[1] 孙倩[1] 谢鹏[1] 白郁华[1] 刘兆荣[1] 李金龙[1] 陆思华[1] 

机构地区：[1]北京大学环境科学与工程学院,北京100871

出　　处：《环境科学》2009年第11期3159-3166,共8页Environmental Science

基　　金：国家重点基础研究发展规划(973)项目(2005CB422200)

摘　　要：分别于2007年在泰安市郊区和深圳市郊区采集了大气颗粒物并同时对降水进行了分级采样,通过降水过程中降水化学特征的变化和降水前后颗粒物浓度和化学组成的改变,讨论了云下冲刷过程中大气颗粒物对降水化学组分的贡献和降水对颗粒物的去除作用.泰安降水雨量加权pH为5.97,总可溶解离子浓度为1 187.96μeq.L-1,PM10的质量浓度为131.76μg/m3,PM2.5为103.84μg/m3.深圳降水雨量加权pH为4.72,总可溶解成分离子浓度为175.89μeq.L-1,PM10的质量浓度为56.66μg/m3,PM2.5为41.52μg/m3.泰安和深圳降水过程中pH和离子浓度都逐渐降低,冲刷过程主要是中和作用.泰安和深圳降水中Na+和Ca2+的去除效率较高,NH4+和NO3-去除效率较低.两地降水化学性质的差别取决于云水酸度、大气颗粒物性质和大气中酸碱性气体差别的共同作用.降水对大气颗粒物质量浓度、离子组分和元素组分都有显著清除作用.Rain and atmospheric particle samples were collected in the rural area of Taian and Shenzhen in 2007, respectively. Rain sampling was carried out during the precipitation process and several samples were got from the beginning of one precipitation to the end. The chemical character changes during precipitation and the changes of concentration of particles before and after rain were studied in this research to understand the contribution of particles on the rain chemical character and the rain-out effect for particles. The volume-weighted mean pH of rainwater in Taian was 5.97 and the total concentration of ions was 1 187.96 μeq· L^-1 . The mass concentration of PM10 in Taian was 131.76 μg/m3 and that of PM2.5 was 103.84μg/m3 . The volume-weighted mean pH of rainwater in Shenzhen was 4.72 and the total concentration of ions was 175.89 μeq·L^-1 . The mass concentration of PM10 in Shenzhen was 56.66 μg/m3 and that of PM2.5 was 41.52 μg/m3 . During precipitation process pH and ion concentration of rain decrease and it is shown the neutralizing effect happens. The difference between rainwater of Taian and Shenzhen is due to cloud water acidity, atmospheric particles character and atmospheric acid-basic gases concentration. The clean-up effect of Na＋ and Ca2＋ by rain is high and which of NH4＋ and NO3- is low. The clean-up effect for mass concentration, ions concentration and element concentration of particles by rain are significant.

关 键 词：酸雨 大气颗粒物 云下冲刷 中和作用 清除作用 

分 类 号：X513[环境科学与工程—环境工程]