济南市采暖季不同污染天气PM_(2.5)及其PAHs和元素组分污染特征及源解析

Characterization and source analysis of PM_(2.5)and its PAHs and element components in different polluted weather in Jinan heating season

我国近年大气污染治理虽取得一定成效,但冬季采暖期仍是大气重污染频发时期.为探究济南市采暖季不同污染天气PM_(2.5)及其负载组分的污染特征及来源,采集2018年12月—2019年1月济南市中心某社区室外大气PM_(2.5)样本,用重量法计算PM_(2.5)浓度,GC/MS检测PAHs浓度,ICP-MS检测元素组分.发现济南市采暖季污染天PM_(2.5)浓度与室外相对湿度呈显著正相关(r=0.7968,P<0.05);污染天PM_(2.5)浓度显著高于非污染天,其负载的PAHs和元素浓度均随PM_(2.5)的升高而升高,两种天气下PAHs环数占比、特征比值法和元素富集因子法得到的源解析结果接近.提示污染天PM_(2.5)虽显著升高,但PM_(2.5)中PAHs和元素均主要来自煤炭燃烧和尾气排放,污染源类型的构成却没有发生明显改变.

Although some remarkable progress has been achieved in air pollution control in China in recent years,winter heating season is still a period of most concern due to its frequent air pollution.In order to explore the pollution characteristics and sources of PM_(2.5)and its load components in different polluted period during the heating season in Jinan,atmospheric PM_(2.5)were collected in an urban community of Jinan from December 2018 to January 2019.PM_(2.5)was measured by gravimetric method and PAHs and elements were analyzed by GC/MS and ICP-MS separately.It was found that there was significantly positive relation between PM_(2.5)and atmospheric relative humidity during the heating season(r=0.7968,P<0.05),and the concentration of PM_(2.5)in polluted period was significantly higher than that in non-polluted period,and the PAHs and element concentrations accumulated with the increase of PM_(2.5).The source analysis through the ratio of PAHs cycle number,characteristic ratio and element enrichment factor indicated the similar source in the two weather conditions,suggesting that although PM_(2.5)increased significantly on polluted days,the PAHs and elements in PM_(2.5)mainly came from the consistent coal combustion and exhaust emissions,and the composition of pollution sources had not changed significantly.