春节期间西安市南郊细颗粒物中水溶性离子的污染特征

Pollutions characteristics of water-souble ions of fine particle during spring festival over Xi′an southern

运用美国R&P公司TEOM-1400a的ACCU 8通道,分8个时段采集了西安南郊的细颗粒物(PM2.5)样品.运用离子色谱分析检测了样品中9种水溶性离子(Na+、NH4+、K+、Mg2+、Ca2+、F-、Cl-、NO3-和SO24-).结果表明,燃放烟花爆竹时段的PM2.5平均浓度及9种水溶性离子总平均浓度分别高于正常时段的1.6倍和1.3倍,其中0∶00—02∶59时段PM2.5平均浓度及9种水溶性离子总平均浓度高于正常同时段的6.6倍和5.2倍;其中Cl-、SO24-、K+和Mg2+4种离子质量浓度明显增加,分别增加了19.1倍、5.0倍、62.0倍和10.3倍.离子平衡表明燃放烟花时段的气溶胶接近中性略微偏酸性.运用主成分分析判断得知,水溶性离子主要来源于燃放烟花爆竹及少量机动车尾气和燃煤.

To predict the impact of fireworks activities on ambient air quality of urban areas,40 samples were collected,and the mass concentration of PM2.5 were also monitored series during 2011 Spring Festival（Chinese New Year） in Xi′an City.Nine water-soluble ions（Na＋,NH＋4,K＋,Mg2＋,Ca2＋,F-,SO2-4,NO-3 and Cl-） in of 3-hr integrated PM2.5 were analyzed using ion chromatography.The results show that,during the fireworks activities on Spring Festival Holiday,the average concentations of PM2.5 and the total of nine water-soulale ions were 1.6 and 1.3 times higher than the normal days,respecitively.Specifically,from 0 ∶00 to 02 ∶59 on Spring Festival,the average mass concentrations of PM2.5 and the total of nine water-soluble ions dramatically increased to 6.6 and 5.2 times higher than normal day;the mass concentrations of Cl-,SO2-4,K＋ and Mg2＋ were 19.1,5.0,62.0,and 10.3 times higher than the average concentrations in normal days.The results from ion balance caculation analysis suggested that the fierworks samples were weak acidic.The major sources of PM2.5 were characterized as fireworks acivitites,followed by transportation exhaust and fossil fuel combustion.