南昌市新城区大气降水化学特征与主要成分来源解析  

Chemical Characteristics and Main Sources of Atmospheric Precipitation in New Urban District of Nanchang City

作　　者：魏宸 黄虹[1] 邹长伟[1] 周熠[1] 

机构地区：[1]南昌大学资源环境与化工学院,江西南昌330031

出　　处：《环境科学研究》2016年第11期1582-1589,共8页Research of Environmental Sciences

基　　金：国家自然科学基金项目(41265009)

摘　　要：为了解南昌新城区大气降水化学特性和来源,于2013年5月15日—2014年1月24日采集当地有效降水样品39个,分析其降水化学特性,包括p H、电导率和主要离子(Na+、NH4+、K+、Mg^(2+)、Ca^(2+)、F-、Cl-、NO3-和SO42-)的浓度.结果表明:南昌市新城区降水p H介于3.67~5.86之间,降水量加权平均值为4.63;电导率在6.13~73.01μS/cm之间,降水量加权平均值为29.02μS/cm;降水中总离子浓度为154.1~474.3μeq/L,降水量加权平均值为300.1μeq/L.SO42-、Ca^(2+)、NH4+和NO3-是降水中的主要离子,合计占总离子浓度的82.6%.SO42-/NO3-(当量离子浓度比)在1.82~3.61之间,平均值为2.66.南昌市新城区降水相对酸度为0.43,57.0%的致酸物质被大气中碱性物质中和,主要的酸度中和因子为Ca^(2+)和NH4+,分别贡献50.0%和36.6%的中和量.阴阳离子三角图分析表明,阴离子主要来自人为源;阳离子来源包括地壳源和人为源.富集系数分析表明,99.5%的Ca^(2+)、88.4%的K+、63.0%的Mg^(2+)来自地壳源;Mg^(2+)、K+、Ca^(2+)的海洋源输入分别为30.7%、4.6%和0.5%;1.2%的Cl-来自地壳源,55.8%来自海洋源,43.0%来自人为源;96.8%的SO42-和99.5%的NO3-来自人为源.研究显示,南昌市新城区的降水为混合型降水,人为源对大气环境产生了重要影响.Chemical characterization of atmospheric precipitation in the new district of Nanchang City was conducted for samples collected from May 15 th,2013 to January 24 th,2014. The results showed that p H values ranged from 3. 67 to 5. 86,with volume-weighted average4. 63. The electrical conductivity ranged from 6. 13 μS/cm to 73. 01 μS/cm,averaging 29. 02 μS/cm. The total ion concentration in the precipitation samples ranged from 154. 1 to 474. 3 μeq/L,with weighted average of 300. 1 μeq/L. Soluble ions such as SO42-,Ca^2＋,NH4＋and NO3-were identified to be the main ions in the precipitation,accounting for 82. 6% of the total concentration. The sulfate/nitrate ratio ranged from 1. 82 to 3. 61,with 2. 66 average. The relative acidity of precipitation was 0. 43,and 57. 0% of the acid material was neutralized by alkaline substances in the atmosphere. The main acidity neutralization factors were Ca^2＋and NH4＋,contributing50. 0% and 36. 6% of the neutralization,respectively. Cation and anion triangle qualitative analysis showed that the anions mainly originated from anthropogenic sources,and the cations originated from both crustal and anthropogenic sources under enrichment factor quantitative analysis. Further analysis showed that 99. 5% of Ca^2＋,88. 4% of K＋and 63. 0% of Mg^2＋were derived from crustal sources,and 30. 7% of Mg^2＋,4. 6% of K＋,and 0. 5% of Ca^2＋ions were imputed by marine sources. 1. 2% of Cl-ion was derived from the crustal source,55. 8% was from the marine source,and 43. 0% was from man-made source. 96. 8% of SO42-and 99. 5% of NO3-were from anthropogenic sources. The overall results suggested that the Nanchang precipitation is a mixed type precipitation,and anthropogenic sources have an important implication in the present study.

关 键 词：大气降水 化学特征 离子 南昌市 

分 类 号：X51[环境科学与工程—环境工程]