永州市大气降水化学特征及酸雨成因分析

Analysis on the Chemical Characteristics of Atmospheric Precipitation and the Causes of Acid Rain in Yongzhou City

通过研究2016—2020年永州市大气降水中离子的组成特征和变化,本文分析离子可能的来源和酸雨的成因。结果表明,近年来,永州市酸雨污染有所缓解,酸雨成因也有所改变。降水酸性、酸雨频率、硫酸根与硝酸根的比值均呈下降趋势,但不显著。降水离子中,硫酸根仍是降水致酸的主要原因,但作用逐年弱化;硝酸根的致酸作用逐年上升,表明降水污染已从煤烟型为主,向工业废气和机动车排气复合型转化。

By studying the composition characteristics and changes of ions in the atmospheric precipitation in Yongzhou City from 2016 to 2020,this paper analyzes the possible sources of ions and the causes of acid rain.The results show that in recent years,the acid rain pollution in Yongzhou City has been alleviated,and the causes of acid rain have also changed.The acidity of precipitation,the frequency of acid rain,and the ratio of sulfate to nitrate all show a decreasing trend,but not significant.Among the precipitation ions,sulfate is still the main cause of acid in precipitation,but its role is weakened year by year;the acid-causing effect of nitrate has been increasing year by year,indicating that the precipitation pollution has changed from being dominated by soot-based type to a composite type of industrial waste gas and motor vehicle exhaust.