嘉兴市酸雨变化特征及来源分析  

Chemical Characteristics and Source of Acid Precipitation in Jiaxing

作　　者：浦国佳 张颖龙 俞丽琅 王海勇 苏营营 陈辉 李莉 PU Guojia;ZHANG Yinglong;YU Lilang;WANG Haiyong;SU Yingying;CHEN Hui;LI Li(Jiaxing Eco-Environmental Monitoring Center of Zhejiang Province,Jiaxing 314000,China)

机构地区：[1]浙江省嘉兴生态环境监测中心,浙江嘉兴314000

出　　处：《中国环境监测》2025年第1期66-75,共10页Environmental Monitoring in China

基　　金：生态环境部长江生态环境保护修复联合研究二期项目(2022-LHYJ-02-0503-02)。

摘　　要：为研究嘉兴市酸雨变化特征以及来源,对2006-2021年嘉兴市7个降水监测点的酸雨年际变化特征、空间分布特征、季节变化特征以及离子来源进行了分析。结果表明,2006-2021年,全市酸雨污染整体呈先恶化后改善的趋势。其中:2021年,非酸雨区数量占比首度超过其他级别酸雨区占比之和;研究期内,海盐县酸雨污染改善最为显著。总体上,夏季酸雨污染相对较轻,春季和冬季酸雨污染相对较重。离子来源分析结果显示:SO_(4)^(2-)是嘉兴市降水中的主要离子及影响降水pH的主要因子,F-对嘉兴市酸雨的影响显著;降水中的致酸离子SO_(4)^(2-)和NO_(3)^(-)的来源主要为人为来源,Cl^(-)和Mg^(2+)的主要来源为海洋,Ca^(2+)的主要来源为地壳,K^(+)的主要来源为人为来源。通过分季节对2020年降水进行后向轨迹模拟发现:在春季和夏季,西南方向气流和海洋来源气流所占比例比较接近,降水pH受到海洋源和人为源的共同影响,两个季节的降水酸度也比较接近;在秋季和冬季,海洋来源气流带来的大量水汽对离子的稀释作用明显,导致降水酸度相对较弱。相较于西北方向污染物远距离输送,本地及周边上空大气污染物输送对嘉兴市降水酸度的影响更大。To study the variation characteristics and sources of acid rain in Jiaxing,the interannual variation,spatial distribution,seasonal variation and ion sources of acid rain at 7 precipitation monitoring points in Jiaxing from 2006 to 2021 were analyzed.The results showed that from 2006 to 2021 the overall acid rain pollution in the city showed a trend of worsening first and then improving.In 2021,the quantity proportion of non-acid rain areas exceeded the sum of other levels of acid rain areas for the first time,and the improvement of acid rain pollution was most significant in Haiyan County.From 2006 to 2021,acid rain pollution in summer was relatively light,while air pollution in spring and winter was relatively heavy.According to ion source analysis,SO_(4)^(2-) was the main ion in Jiaxing precipitation and the main factor affecting pH value of acid rain.The influence of F-on acid rain in Jiaxing was prominent.The acidigenic ions in precipitation of SO_(4)^(2-) and NO_(3)^(-) were mainly from anthropogenic sources.The main source of Cl^(-)and Mg^(2+)was the ocean,while the main source of Ca^(2+)was the earths crust,and the main source of K^(+) was anthropogenic.Through the backward trajectory simulation of 2020 precipitation by seasons,it was found that the proportion of southwest airflow and oceanic airflow in spring and summer was relatively close,and the pH of precipitation was influenced by both marine and anthropogenic sources,with the acidity of precipitation in these two seasons also being relatively close.In autumn and winter,the ocean source airflow brought a lot of water vapor to dilute ions obviously,and the precipitation acidity was relatively weak.Compared with the long-distance transportation of pollutants in the northwest direction,the local and surrounding air pollutants had a greater impact on the precipitation acidity in Jiaxing.

关 键 词：嘉兴 酸雨 水化学特征 离子来源 气流轨迹聚类分析 

分 类 号：X517[环境科学与工程—环境工程]