厦门市2021年大气降水化学组分变化趋势及来源分析

Variation trends and sources of the chemical components of atmospheric precipitation in Xiamen during 2021

为了解厦门市大气降水化学组分及其变化趋势,对2021年采集的厦门市大气降水进行了分析,监测因子主要包括pH、电导率、降水量及化学组分(硫酸根、硝酸根、铵离子、氟离子、氯离子、钙离子、镁离子、钠离子、钾离子)。分析结果表明,2021年厦门全市降水pH值范围为4.01~6.39,pH加权平均值为4.99,酸雨发生率为75.9%。其中小坪点位pH值范围为4.01~5.94,pH加权平均值为4.87,酸雨发生率为87.0%;洪文点位pH范围为4.61~6.39,pH加权平均值为5.33,酸雨发生率为55.2%。PMF来源解析表明,市区洪文点位降水中离子的主要来源为工业及燃烧源、海盐、机动车尾气、扬尘源,其贡献率分别为20.3%、26.7%、19.6%、33.4%;郊区小坪点位降水中离子的主要来源为生物及农业源、海盐、机动车尾气、工业及燃烧源,其贡献率分别为29.5%、31.5%、26.2%、12.8%。

To obtain the chemical properties and temporal variation of atmospheric precipitation in Xiamen,the pH,conductivity,precipitation,and the chemical components of atmospheric precipitation at Xiamen in 2021 were investigated.The pH varied from 4.01 to 6.39,with an average value of 4.99,and the probability of acid rain was 75.9%.The average pH of the suburban site was 4.87(4.01~5.94),and the probability of acid rain was 87.0%;as for the urban site,the average pH was 5.33(4.61~6.39),and the probability of acid rain was 55.2%.The results of source appointment with Positive matrix factor analysis revealed that the sources of the precipitation in urban site included the industrial and combustion sources,sea salt source,vehicle source,and dust source,with contributions of 20.3%,26.7%,19.6%,and 33.4%,respectively;the major sources of the precipitation in the suburban site were the biological and agriculture sources,sea salt source,the mix sources of industrial and combustion,and dust source,which contributed 29.5%,31.5%,26.2%,and 12.8%,respectively.