中国西南酸雨区降水化学特征研究进展

发布时间：2018-02-26 20:00

本文关键词： 西南酸雨区降雨 pH 中和作用离子来源　出处：《环境科学》2017年10期 　论文类型：期刊论文

【摘要】：西南酸雨区为我国主要酸雨沉降区,且是全球三大喀斯特集中分布区之一.本文将该区9个地点的降雨资料进行了总结、整理和分析,数据包括pH值和主离子成分(Cl~-、SO_4~(2-)、NO_3~-、Ca~(2+)、NH_4~+、Mg~(2+)、K~+、Na~+).该地区降雨中的主要阴离子为SO_4~(2-)和NO_3~-,主要阳离子为Ca~(2+)和NH_4~+.与我国其它地区相比,其酸性离子、碱性离子和总离子浓度均普遍高于东南地区、而低于我国北方地区.西南酸雨区主要以pH值为4.5~5.6的弱酸性降雨为主,占总降雨频次的58%左右.根据酸、碱性离子的相关性、中和因子等分析结果,该区雨水中的酸性物质可能受到了碱性离子的中和作用,其中起主要中和作用的离子为Ca~(2+)和NH_4~+.将该区雨水pH值和酸、碱性离子浓度与我国其它地区进行对比研究发现,西南酸雨区降雨受到的中和作用要强于东南地区,但弱于北方地区的降雨.通过对西南酸雨区降雨中主要离子来源的分析和估算,降雨中的酸性离子SO_4~(2-)和NO_3~-主要来自于人为污染;99.7%的Ca~(2+)和84.0%的Mg~(2+)为陆源贡献,这可能与西南地区碳酸盐岩广泛分布有关.
[Abstract]:The southwest acid rain area is the main acid rain subsidence area in China, and is one of the three largest karst concentrated distribution areas in the world. The rainfall data of 9 sites in this area are summarized, sorted out and analyzed in this paper. The data include pH value and the main ion composition Cl-n-so _ 4 ~ + _ 2 ~ ~ ~ + ~ ~ ~. The concentrations of alkaline ions and total ions are generally higher than those in southeast China, but lower than those in northern China. The weak acid rainfall with pH value of 4.5 ~ 5.60% accounts for about 58% of the total rainfall frequency in the southwest acid rain area, according to the correlation of acid and alkaline ions. Neutralization factors and other analysis results show that the acidic substances in Rain Water in this area may be neutralized by alkaline ions, among which the main neutralizing ions are Ca~(2) and NH4-. The comparison of alkaline ion concentration with other areas in China shows that the precipitation in the southwest acid rain area is more neutralized than that in the southeast region. Through the analysis and estimation of the main ion sources in the southwest acid rain area, the acid ions so _ 4 ~ + ~ (2) and no _ 3 ~ (3), mainly from the Ca~(2 of 99.7% of the total anthropogenic pollution, and 84.0%% Mg~(2) contributed to the land source. This may be related to the widespread distribution of carbonate rocks in southwest China.
【作者单位】：中国科学院地质与地球物理研究所;中国科学院大学;
【基金】：国家重点基础研究发展规划(973)项目(2013CB956401)
【分类号】：X517

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