大气污染物与降水中酸性离子相关性研究

Analysis of Correlation between Atmospheric Pollutants and Acid Precipitation

对二氧化硫(SO2)、二氧化氮(NO2)以及降水中的典型酸性离子浓度进行连续监测,分析了大气SO2、NO2与降雨中SO2-4、NO-3离子之间的相关性。石嘴山市五年期间SO2排放量略有降低,NO2排放量逐年增加。大气中SO2及NO2分别在2009年及2010年达到最大值,为0.08 mg·m-3及0.04 mg·m-3;SO2-4/NO-3比例逐年下降,由2007年的19.74降低至2012年的3.28;石嘴山市近年来降水类型的转变一方面原因是在SO2减排背景下的NO2大幅增加,另一方面是大气中氧化水平的不断升高,使NO2氧化率大幅增加。

The correlation of the atmospheric precursor pollutants and the precipitation type in recent years was studied by analyzing the pollution trend of sulfur and nitrogen oxides in the atmosphere and the change of the precipitation type. The results showed that although a reduction of SO2 emission was occurred, a significant increase of NO2 concentration was observed. The SO2 and NO2 reached their maximum concentrations of ca. 0. 08 mg · m^-3 in 2009 and 0. 04 mg· m^-3 in 2010, respectively. The SO24-/NO3 ratios in the precipitation decreased from 19. 74 to 3.28 between 2007 and 2012, indicating that the acid rain type was gradual transition from the sulfate type to the mixed type. The change of acid rain type of Shizuishan City in recent years was mainly attributed to the following two reasons： （ 1 ） the emission of NO2 was significantly increased during the SO2 emission reduction progress; （2） the oxidation ability of the atmosphere became stronger, and the oxidation rate of NO2 to NO3 increased faster than that of the SO2 to SO4^2-.