Study on dry deposition of sulfur dioxide to the Chinese desert soil and estimation of its dry removal from the atomosphere

为了获得中国沙漠和黄沙土上SO2干沉降量估算大气中SO2脱除量的基础数据，我们研究了上述土壤和几种模型土壤在含有微量SO_2、NO_2和HNO_3的实验气体中的暴露情况。结果表明，土壤颗粒的酸度与土壤中的钙含量密切相关。结果表明，土壤酸度与酸雨出现频率的关系2)中国沙漠、黄沙土壤中SO_2的干沉积速率取决于土壤碱度和暴露气体的湿度；3)HNO_3在不同土壤中的干沉积速率与SO_2的干沉积速率相近，而NO_2的干沉积速率远低于SO_2。S(VI)/S(IV)沉积在沙漠、黄沙、5)人工肺用于低浓度SO2和气态HNO2的采集，以估算其在中国荒漠和黄沙土上干沉降对大气中SO2的脱除量，有待进一步研究。

In order to obtain the fundamental data to estimate the removal amount of SO_2 from the atmosphere by its dry deposition on the Chinese desert and yellow sand soils, we investigated the exposure of the above soils and several model soils to the experimental gases containing trace level of SO_2, NO_2, or HNO_3. The results obtained by the above exposure experiments etc, were summarized as below.1) Elemental analyses for desert yellow sand soils in China were achieved. The results indicated the intimate relation of acidity of soil particles with content of Ca. It suggests the relation of soil acidity with the frequency of acid rain appearence.2) Dry deposition velocity of SO_2 to desert and yellow sand soils in China depended on soil alkalinity and humidity of exposure gas.3) Dry deposition velocity of HNO_3 to various soils was similar level of that of SO_2. While, that of NO_2 was much lower than that of SO_2.4) S(VI)/S(IV) deposited on desert, yellow sand, and model soils was increased with increase in the humidity of exposure gas and the irradiation time with a simulated sun-light (black-light).5) The artificial lung was applied to collection of low concentration SO_2 and gaseous HNO_3.6) In order to estimate the removal amount of SO_2 from the atmosphere by its dry deposition on the Chinese desert and yellow sand soils, further investigation is needed.