| 北京市大气降水理化特性的演变及其重要的环境效应 |
| 摘要点击 2013 全文点击 390 投稿时间：2023-07-31 修订日期：2023-10-09 |
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| 中文关键词 大气降水 理化特性 时间变化 湿沉降通量 清除机制 |
| 英文关键词 atmospheric precipitation physical and chemical characteristics temporal variations wet deposition fluxes scavenging mechanism |
| 作者 | 单位 | E-mail | | 韩力慧 | 北京工业大学环境与生命学部, 北京 100124
区域大气复合污染防治北京市重点实验室, 北京 100124 | hlh@bjut.edu.cn | | 肖茜 | 北京工业大学环境与生命学部, 北京 100124
区域大气复合污染防治北京市重点实验室, 北京 100124 | | | 杨雪梅 | 北京工业大学环境与生命学部, 北京 100124
区域大气复合污染防治北京市重点实验室, 北京 100124 | | | 齐超楠 | 北京工业大学环境与生命学部, 北京 100124
区域大气复合污染防治北京市重点实验室, 北京 100124 | | | 田健 | 北京工业大学环境与生命学部, 北京 100124
区域大气复合污染防治北京市重点实验室, 北京 100124 | | | 兰童 | 北京工业大学环境与生命学部, 北京 100124
区域大气复合污染防治北京市重点实验室, 北京 100124 | | | 程水源 | 北京工业大学环境与生命学部, 北京 100124
区域大气复合污染防治北京市重点实验室, 北京 100124 | | | 郑爱华 | 北京师范大学分析测试中心, 北京 100875 | | | 郭敬华 | 北京师范大学分析测试中心, 北京 100875 | |
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| 中文摘要 |
| 通过采集北京市2018、2019和2021年大气降水样品,研究了北京市大气降水中主要金属元素和水溶性离子浓度,重金属、水溶性离子、溶解性无机氮（DIN）和无机硫（SO42--S）湿沉降通量及其对生态环境的影响,以及典型降水过程对大气污染物的清除机制. 结果表明,研究期间北京市降水多呈中性或碱性,酸雨率极低,仅为3.06%. 2018、2019和2021年降水中主要金属元素总浓度依次为（4 787.46 ±4 704.31）、（7 663.07 ±8 395.05）和（2 629.13 ±2 369.51）μg·L-1,离子总当量浓度依次为（851.68 ±649.16）、（973.98 ±850.94）和（644.31 ±531.16）μeq·L-1,二者年际变化均表现为：2019年>2018年>2021年；春季、夏季、秋季和冬季的主要金属元素总浓度的季节均值分别为（9 624.25 ±7 327.92）、（4 088.67 ±5 710.14）、（3 357.68 ±3 995.64）和（6 203.19 ±3 857.43）μg·L-1,春季、夏季、秋季和冬季的离子总当量浓度的季节均值分别为（1 014.71 ±512.21）、（729.83 ±589.90）、（724.35 ±681.40）和（1 014.03 ±359.67） μeq·L-1,二者季节变化均表现为：春季>冬季>夏季>秋季. NO3-和SO42-是主要的致酸离子,而NH4+和Ca2+是主要的酸中和离子. 值得注意的是重金属Cd的湿沉降通量虽然较低,仅占所有重金属湿沉降通量的（0.13 ±0.04）%,但Cd的土壤安全年限为291 a,显著低于其他重金属,因此,其生态风险相对较高. 水溶性离子NH4+、Ca2+、NO3-和SO42-的湿沉降通量占总离子湿沉降通量的（85.72 ±2.18）%,对生态环境的综合影响可能较大. DIN湿沉降通量主要以NH4+-N为特征,在夏季对生态环境具有重要的促进作用. SO42--S湿沉降通量在夏季较高,对生态环境的促进作用较大. 大气降水对污染物的清除作用受诸多因素影响,这些因素协同作用直接影响降水对污染物的清除机制. |
| 英文摘要 |
| Atmospheric precipitation samples were collected in 2018, 2019, and 2021 in Beijing to study the concentrations and changes of the main metal elements and water-soluble ions； the wet deposition fluxes of heavy metals, water-soluble ions, dissolved inorganic nitrogen, and sulfur in the atmospheric precipitation and their impacts on the ecological environment； and the scavenging mechanisms of the typical precipitation to atmospheric pollutants during the study period. The results showed that the precipitation in Beijing during the study period was mostly neutral or alkaline, and the frequency of acid rain occurrence was very low, only accounting for 3.06%. The total concentrations of major metal elements in 2018, 2019, and 2021 were （4 787.46 ±4 704.31）, （7 663.07 ±8 395.05）, and （2 629.13 ±2 369.51） μg·L-1, respectively. The total equivalent concentrations of ions in 2018, 2019, and 2021 were （851.68 ±649.16）, （973.98 ±850.94）, and （644.31 ±531.16） μeq·L-1, respectively. The interannual changes in major metal elements and ions followed the order of 2019 > 2018 > 2021. The seasonal average total concentrations of major metal elements in spring, summer, autumn, and winter were （9 624.25 ±7 327.92）, （4 088.67 ±5 710.14）, （3 357.68 ±3 995.64）, and （6 203.19 ±3 857.43） μg·L-1, respectively, and the seasonal average total equivalent concentrations of ions in spring, summer, autumn, and winter were （1 014.71 ±512.21）, （729.83 ±589.90）, （724.35 ±681.40）, and （1 014.03 ±359.67） μeq·L-1, respectively, all presenting the order of spring > winter > summer > autumn. NO3- and SO42- were the main acid-causing ions in precipitation, whereas NH4+ and Ca2+ were the main acid-neutralizing ions. The wet deposition fluxes of the heavy metal Cd were very low [（0.05 ±0.01） mg·（m2·a）-1], only accounting for （0.13 ±0.04）% of the total wet deposition fluxes of main metal elements； however, its soil safety years were 291 years, significantly lower than those of other heavy metals, displaying that its ecological risk was relatively the highest. The total wet precipitation flux of water-soluble ions NH4+, Ca2+, NO3-, and SO42- accounted for （85.72 ±2.18）% of the wet precipitation flux of total ions, suggesting that their comprehensive impact on the ecological environment might have been higher. DIN wet deposition flux was mainly characterized by NH4+-N, which had a positive impact on the ecological environment in summer. SO42--S wet deposition flux was higher in summer, so its positive impact on the ecological environment was also greater. The scavenging effects of atmospheric precipitations to pollutants from the air were impacted by various factors, and the synergism effects of these factors could directly influence the scavenging mechanisms of precipitation to pollutants. |
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