Rastegari Mehr Meisam, Keshavarzi Behnam, Sorooshian Armin
Department of Applied Geology, Faculty of Earth Science, Kharazmi University, Tehran 15614, Iran.
Department of Earth Sciences, College of Sciences, Shiraz University, Shiraz 71454, Iran.
Sci Total Environ. 2019 Jun 10;668:1213-1221. doi: 10.1016/j.scitotenv.2019.03.082. Epub 2019 Mar 7.
The influence of pollutant sources on rainwater chemistry is investigated at an industrial coastal site in Iran (Mahshahr) where frequent dust storms occur throughout the year. For this purpose, rainwater samples from two main pluvial systems were collected and analyzed for major ions and selected heavy metals (Al, Cu, Ni, Pb and Zn). The differences in calculated and measured pH values of rainwater pointed to the important effect of neutralizing agents, specifically Ca, Na and Mg, in offsetting the high acidity generated by NO and SO to yield alkaline rainwater. A comparison of species concentration ratios relative to those for pure seawater and Earth's crust revealed that nearly all NO and most Ca, SO and Mg originated from non-marine and local sources. Compared with other areas around the world, some heavy metals (particularly Zn) displayed higher concentrations in Mahshahr rainwater. Enrichment factor (EF) analysis revealed that Cu and Ni were moderately enriched, while Pb and Zn in particular (EF > 100) were highly enriched indicating that these species in rainwater stemmed from anthropogenic activities. Positive matrix factorization (PMF) modeling indicated that the four main pollutant sources impacting the regional rainwater were soil, combustion processes, marine emissions, and the local industrial sources.
在伊朗一个沿海工业城市（马赫沙尔）开展了污染物来源对雨水化学性质影响的研究，该地区全年频繁出现沙尘暴。为此，采集了两个主要降雨系统的雨水样本，并对主要离子和选定的重金属（铝、铜、镍、铅和锌）进行了分析。雨水计算pH值和测量pH值的差异表明，中和剂（特别是钙、钠和镁）对抵消由氮氧化物和硫氧化物产生的高酸度以形成碱性雨水具有重要作用。将各物种浓度比与纯海水和地壳中的浓度比进行比较后发现，几乎所有的氮氧化物以及大部分的钙、硫氧化物和镁均来自非海洋和本地来源。与世界其他地区相比，马赫沙尔雨水中的一些重金属（特别是锌）浓度较高。富集因子（EF）分析表明，铜和镍有中度富集，而铅和锌尤其如此（EF>100），属于高度富集，这表明雨水中的这些物种源自人为活动。正定矩阵因子分解（PMF）模型表明，影响该地区雨水的四个主要污染物来源是土壤、燃烧过程、海洋排放和当地工业源。
