聊城市秋季PM_(2.5)中水溶性离子污染特征及来源解析  

Pollution characteristics and source analysis of water-soluble ions in PM_(2.5) during autumn in Liaocheng City

作　　者：张敬巧[1] 罗达通 王少博 王涵[1] 胡文征 李慧[1] 刘锐泽 王淑兰[1] ZHANG Jingqiao;LUO Datong;WANG Shaobo;WANG Han;HU Wenzheng;LI Hui;LIU Ruize;WANG Shulan(Chinese Research Academy of Environmental Sciences;Hunan Research Academy of Environmental Protection;Zibo Environmental Pollution Prevention and Control Center)

机构地区：[1]中国环境科学研究院 [2]湖南省环境保护科学研究院 [3]淄博市环境污染防控中心

出　　处：《环境工程技术学报》2021年第4期617-623,共7页Journal of Environmental Engineering Technology

基　　金：大气重污染成因与治理攻关项目(DQGG0107-21)。

摘　　要：于2017年10月15—11月14日在聊城市区采集PM_(2.5)样品,并对其中的水溶性离子(Na^(+)、NH_(4)^(+)、K^(+)、Mg^(2+)、Ca^(2+)、F-、Cl^(-)、NO_(3)^(-)、SO_(4)^(2-))进行分析测试,以研究聊城市秋季PM_(2.5)污染特征。结果显示:观测期间PM_(2.5)浓度均值为(104.9±50.5)μg/m^(3),超过GB 3095—2012《环境空气质量标准》二级标准浓度限值0.40倍;水溶性离子浓度为(52.2±35.1)μg/m^(3),占PM_(2.5)的45.7%±11.3%,其中NO_(3)^(-)、SO_(4)^(2-)和NH_(4)^(+)为主要组分,占水溶性离子和PM_(2.5)的比例分别为85.2%和45.0%;随PM_(2.5)污染加重,水溶性离子浓度升高,NH_(4)^(+)占比亦逐渐升高,NO_(3)^(-)及SO_(4)^(2-)占比先升高后有所下降,其他离子占比尤其是Ca^(2+)随之下降,表明PM_(2.5)浓度的升高主要受二次无机转化影响;硫转化率(SOR)与氮转化率(NOR)均值分别为0.28和0.27,表明聊城市秋季SO_(2)与NO_(2)转化速率较高,二次无机污染较为严重,另外SOR及NOR与温度及相对湿度呈显著正相关,且SOR对相对湿度更加敏感而NOR对温度更为敏感;聊城市秋季PM_(2.5)呈弱碱性,NH_(4)^(+)的存在形式主要是(NH4)2SO_(4)和NH_(4)NO_(3)。主成分分析结果表明,二次无机转化、扬尘源和工业生产排放是聊城市秋季PM_(2.5)中水溶性离子的主要来源。PM_(2.5)samples were collected during autumn in Liaocheng City from October 15th to November 14th,2017,and the water-soluble ions(Na^(+),NH_(4)^(+),K^(+),Mg^(2+),Ca^(2+),F-,Cl^(-),NO_(3)^(-)and SO_(4)^(2-))were analyzed to study the pollution characteristics of PM_(2.5)in autumn in Liaocheng City.The results showed that PM_(2.5)mean concentration was(104.9±50.5)μg/m^(3)during the observation period,0.40 times higher than the daily average concentration limit of GradeⅡstandard of Ambient Air Quality Standards(GB 3095-2012).The average concentration of water-soluble ions was(52.2±35.1)μg/m^(3),which accounted for 45.7%±11.3%of PM_(2.5).SO_(4)^(2-),NO_(3)^(-)and NH_(4)^(+)were the main ions,accounting for 85.2%of the water-soluble ions and 45.0%of PM_(2.5).As the air pollution got serious,the concentrations of water-soluble ions increased.In addition,the proportion of NH_(4)^(+)increased gradually,that of SO_(4)^(2-),No 3-increased first but then decreased,while that of other ions especially Ca^(2+)decreased,which indicated that the increase of PM_(2.5)concentration was mainly affected by the secondary inorganic transformation.The average sulfur oxidation rate(SOR)and nitrogen oxidation rate(NOR)during the observation period were 0.28 and 0.27,respectively,which showed that the secondary transformation of SO_(2)and NO_(2)was higher in autumn and the secondary pollution was much serious.In addition,SOR and NOR were positively correlated with temperature and relative humidity,and SOR was more sensitive to relative humidity,but NOR to temperature.PM_(2.5)in Liaocheng City presented weak alkaline in autumn,and NH_(4)^(+)were primarily in NH_(4)NO_(3)and(NH4)2SO_(4)forms.The results of the principal component analysis revealed that secondary inorganic transformation,dust sources and industry emissions were the main sources of water-soluble ions of PM_(2.5)during autumn in Liaocheng City.

关 键 词：PM_(2.5) 水溶性离子 二次转化 来源解析 聊城市 

分 类 号：X513[环境科学与工程—环境工程]