万州城区空气污染过程中含碳气溶胶的变化特征  

Characteristics of carbonaceous aerosols during air pollution episodes in the urban Wanzhou area

作　　者：黄怡民[1] 张六一[1,2] 刘源 王欢博[2] 彭超[2] 龙娟[1] 杨复沫 HUANG Yimin;ZHANG Liuyi;LIU Yuan;WANG Huanbo;PENG Chao;LONG Juan;YANG Fumo(Key Laboratory of Water Environment Evolution and Pollution Control in Three Gorges Reservoir,Chongqing Three Gorges University,Chongqing 404100;Key Laboratory of Reservoir Aquatic Environment,Chongqing Institute of Green and Intelligent Technology,Chinese Academy of Sciences,Chongqing 400714)

机构地区：[1]重庆三峡学院三峡库区水环境演变与污染防治重点实验室,重庆404100 [2]中国科学院重庆绿色智能技术研究院水库水环境重点实验室,重庆400714

出　　处：《环境污染与防治》2019年第4期445-451,共7页Environmental Pollution & Control

基　　金：国家自然科学基金资助项目(No.41375123);重庆市自然科学基金资助项目(No.cstc2018jcyjAX0236);重庆市教育委员会科技项目(No.KJ1501001;No.KJ1501006);重庆市万州区科技计划项目(No.201503049);重庆三峡学院2018年校级高等教育教学改革研究项目(No.JGQN1814)

摘　　要：于2016年9月28日至10月15日在万州城区对气态污染物、颗粒物及其含碳气溶胶进行了在线连续观测,结合气象参数,分析了含碳气溶胶的污染特征。结果表明,此次持续污染过程主要由颗粒物污染造成,污染天PM_(10)和PM_(2.5)平均质量浓度分别为170.8、123.7μg/m^3,显著高于非污染天。污染天和非污染天PM_(2.5)、NO_x、有机碳(OC)及元素碳(EC)浓度的日变化都呈双峰,但污染天PM_(2.5)、NO_x和OC出现早峰值时间比非污染天推迟1～3h。污染天OC、EC的平均质量浓度分别为28.0、5.4μg/m^3,分别为非污染天的2.2、1.6倍。以非污染天的起始点作为参照点,得到污染天OC、EC的平均增长率分别为159.3%和73.0%,OC污染累积和二次转化贡献率分别为45.8%和54.2%,说明污染过程OC以二次转化为主。并用最小比值法估算了二次有机碳(SOC)含量,得到污染天和非污染天PM_(2.5)中SOC平均质量浓度分别为16.3、5.3μg/m^3,SOC在OC中的占比(以质量分数计)分别为56.1%和39.9%,污染天SOC占比增加,也证明污染过程OC以二次转化为主。污染天静风出现频率比非污染天高,在东南风的影响下,OC、EC易出现高浓度。Continuous measurements of gas pollutants,particulates and carbonaceous aerosols contained were conducted to assess the characteristics of carbonaceous aerosols during a typical air pollution event in the urban Wanzhou from September 28th to October 15th,2016.The results showed that,this continuous pollution process was mainly caused by particulate pollution.The average concentrations of PM 10 and PM 2.5 during polluted days were 170.8 and 123.7μg/m^3,respectively,higher than those during non-polluted days.The diurnal variations of PM 2.5,NO x,organic carbon(OC)and elemental carbon(EC)showed significantly bimodal pattern in both polluted days and non-polluted days.However,the morning peak times of PM 2.5,NO x,and OC concentrations were delayed by about one to three hours during the polluted days.The average OC and EC concentrations were 28.0 and 5.4μg/m^3 during polluted days,which were 2.2 and 1.6 times of non-polluted days,respectively.Compared to the reference point(the first day of non-polluted day),the average growth rates of OC and EC were 159.3%and 73.0%during polluted days.It was estimated the secondary formation was more important than the accumulation process for the increase of OC during polluted days,which accounting for 54.2%and 45.8%,respectively.The secondary organic carbon(SOC)concentrations were estimated by the minimum OC/EC,and the concentrations of SOC during polluted days and non-polluted days were 16.3 and 5.3μg/m^3,accounting for 56.1%and 39.9%to OC,respectively,also verifying the secondary formation source.Higher static wind ratio appeared during polluted days and OC and EC concentrations were generally higher under southeastern conditions.

关 键 词：PM2.5 空气污染过程 有机碳 元素碳 二次有机碳 

分 类 号：X513[环境科学与工程—环境工程]