State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China.
Environ Monit Assess. 2011 Dec;183(1-4):581-92. doi: 10.1007/s10661-011-1963-4. Epub 2011 Mar 8.
To understand the origin and chemical characteristics of precipitation in Hangzhou, rainwater samples were collected from June 2006 to May 2008. All samples were analyzed for pH, electrical conductivity, and major ions (NH⁴⁺, Ca²⁺, Mg²⁺, Na⁺, K⁺, SO₄²⁻, NO₃⁻, F⁻, and Cl⁻). Acidification of precipitation in Hangzhou was serious with volume-weighted mean pH value of 4.5, while frequency of acid rain was 95%. The calculated SO₄²⁻/NO₃⁻ ratio in Hangzhou precipitation was 2.87, which indicated that the precipitation of Hangzhou belonged to sulfate-based acid rain. The results of acid neutralization analysis showed that not all the acidity in the precipitation of Hangzhou was neutralized by alkaline constituents. The results of sea salt contribution analysis showed that nearly all SO₄²⁻, Ca²⁺, and Mg²⁺ and 33.7% of K⁺ were of non-sea origins, while all Na⁺ and Cl⁻ and 66.3% of K⁺ originated from sea sources. The principal component analysis which was used to analyze the sources of various ions indicated that chemical compositions of precipitation in Hangzhou mainly came from terrestrial sources, factory emissions, fuel wood burning, and marine sources.
为了了解杭州降水的成因和化学特征，我们于 2006 年 6 月至 2008 年 5 月采集了雨水样本。所有样本都分析了 pH 值、电导率和主要离子（NH₄⁺、Ca²⁺、Mg²⁺、Na⁺、K⁺、SO₄²⁻、NO₃⁻、F⁻和 Cl⁻）。杭州降水中等雨量加权平均 pH 值为 4.5，表明酸化严重，酸雨频率为 95%。杭州降水的 SO₄²⁻/NO₃⁻比值为 2.87，表明杭州的降水属于硫酸盐型酸雨。酸中和分析的结果表明，杭州降水中并非所有的酸度都被碱性物质中和。海盐贡献分析的结果表明，几乎所有的 SO₄²⁻、Ca²⁺和 Mg²⁺以及 33.7%的 K⁺都不是来自海洋，而所有的 Na⁺和 Cl⁻以及 66.3%的 K⁺都来自海洋。主成分分析用于分析各种离子的来源，表明杭州降水的化学成分主要来自陆地源、工厂排放、薪柴燃烧和海洋源。
