采集了太原市2013年4—12月大气干沉降样品,并使用了离子色谱仪分析了其中的水溶性无机阴阳离子,报道了干沉降中水溶性离子的化学特征、沉降通量和来源分析.结果表明,SO4^2-、Ca^2+和NO3^-是太原市干沉降的主要离子,浓度分别为4258.83、2388.45、1048.35μg·g^-1.干沉降中的水溶性离子浓度水平季节变化趋势为秋季〉夏季〉春季,变化趋势受到排放源和气象因素的影响.降尘通量和水溶性离子沉降通量分别为323.72 mg·m^2·d^-1和21.43 mg·m^2·d^-1.干沉降中硫、氮沉降通量分别为1.55 t·(km^2·a)^-1和0.39 t·(km^2·a)^-1,高于国内其他地区的研究结果.水溶性离子的相关性分析和特征比值结果显示,干沉降中的NO3^-和SO4^2-主要受到燃煤排放影响;Ca^2+和Mg^2+的主要来源除了扬尘外,燃煤也有贡献.
The chemical characteristic of the water-soluble ions( WSIs) in the dry deposition in Taiyuan was reported by the atmospheric dry deposition field sampling from April to December,2013 and the methods of the ultra-sonic extraction and the ion chromatograph analysis. Then,their fluxes were estimated and the sources were discussed based on the WSIs composition and mass concentration levels. As the results showed,SO4^2-( 4258.83 μg·g^-1),Ca^2+( 2388.45 μg·g^-1) and NO3^-( 1048.35 μg·g^-1) were the major ions in the dry deposition. The concentrations of WSIs were the highest in the autumn,followed by the summer and spring,influenced by the emission source and meteorological factors. The fluxes of dry deposition and WSIs were 323.72 and 21.43 mg·( m-2·d)^-1,respectively. And the flux of sulfur and nitrogen by the dry deposition were 1. 55 and0.39 t·( km^2·a)^-1,respectively,which were higher than those in other regions in China. Based on the correlation relationship and mass ratios between the individual WSIs,NO3^- and SO4^2- were mainly from coal combustion while Mg^2+ and Ca^2+ were from the soil dust as well as coal combustion.