Chemical compositions of precipitation at three non-urban sites of Hebei Province, North China: Influence of terrestrial sources on ionic composition
Chemical compositions of precipitation at three non-urban sites of Hebei Province, North China: Influence of terrestrial sources on ionic composition
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DOI：
10.1016/j.atmosres.2016.06.009
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发表时间：
2015-12
影响因子：
5.5
通讯作者：
Yao Wu;Zhifang Xu;Wenjing Liu;T. Zhao;Xuan Zhang;Hao Jiang;Chong Yu;Li Zhou;Xiaode Zhou-Xiaode
中科院分区：
文献类型：
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作者：
Yao Wu;Zhifang Xu;Wenjing Liu;T. Zhao;Xuan Zhang;Hao Jiang;Chong Yu;Li Zhou;Xiaode Zhou-Xiaode
2008年4月至10月在华北地区的三个非城市地点进行了降水化学研究。总共收集了 122 个雨水样品，并对所有样品进行了 pH、EC 和主要离子（F−、Cl−、NO3−、SO42−、K+、Na+、Ca2+、Mg2+ 和 NH4+）分析。所有采样点降水中的主要离子为 SO42−、NO3− 和 Ca2+。较低的 VWM pH 值（5.29）反映了该地区空气污染的加剧。但仍有超过60%的降水量pH值高于6.0，表明我国北方碱性气溶胶的中和作用相当大。主要离子体积加权平均(VWM)浓度和pH值存在明显的季节差异，旱季降水pH值和主要离子VWM浓度较高。这主要是由于不同季节气团来源不同以及对悬浮颗粒物的稀释作用所致。根据[nssCa2++NH4+]/[nssSO42−+NO3−]当量比和中和因子的结果，强酸中和主要由Ca2+引起，其次是NH4+和Mg2+。使用Na作为海洋来源的指标，根据元素比率估算海盐和非海盐的比例。结合相关分析结果，主要酸性离子（SO42−和NO3−）和NH4+主要来源于人类活动，Ca2+和Mg2+主要来源于陆地。总的来说，结果表明，陆地来源是雨水中主要阳离子的重要来源，对降水化学有强烈影响，尤其是在旱季。
Studies on precipitation chemistry were carried out from April to October in 2008 at three non-urban sites in North China. A total of 122 rainwater samples were collected, and all the samples were analyzed for pH, EC and major ions (F−, Cl−, NO3−, SO42 −, K+, Na+, Ca2 +, Mg2 +, and NH4+). The predominant ions in the precipitation were SO42 −, NO3−and Ca2 +at all sampling sites. The low VWM pH value (5.29) reflected the increasing air pollution in this region. But there was still more than 60% of the total precipitation had a pH value higher than 6.0, indicating the considerable neutralizing effects of alkaline aerosols in northern China. The volume-weighted mean (VWM) concentrations of major ions and pH values showed obvious seasonal differences, the precipitation had higher pH values and VWM concentrations of major ions in dry season. This is mainly attributed to the different sources of air masses in different seasons and the dilution effect on suspended particles. According to the equivalent ratio of [nssCa2 ++ NH4+] / [nssSO42−+ NO3−] and the results of neutralization factors, the strong acid neutralization was mainly brought about by Ca2 +followed by NH4+and Mg2 +. Using Na as an indicator of marine origin, the proportions of sea salt and non-sea-salt were estimated from elemental ratios. Combining with the results of correlation analysis, the main acidic ions (SO42 −and NO3−) and NH4+were mainly derived from anthropogenic activities, and Ca2 +and Mg2 +mostly originated from terrestrial sources. In general, the results reflect that terrestrial source was an important source of major cations in rainwater and strongly influenced the precipitation chemistry, especially in dry season.