南岭大瑶山浓雾雾水的化学成分研究

THE STUDY ON FOG-WATER CHEMICAL COMPOSITION IN DAYAOSHAN OF NANLING MOUNTAIN

文中利用 1998年 12月～ 1999年 1月和 2 0 0 1年 2～ 3月在南岭山地采集的雾水样品资料 ,分析了南岭山地浓雾雾水的化学成分 ;对 3次典型浓雾过程雾水的离子浓度及其可能的来源进行了分析 ;发现酸雾的频率达 5 1% ,酸雾的危害不容忽视。南岭山地的浓雾雾水中的诸离子浓度远高于雨水。不同过程雾水的化学特征变化差异明显 ,在雾水中浓度最高的阴离子是SO2 -4,其次是NO-3 ;阳离子Ca2 + ,NH+ 4 的浓度最高。雨水比雾水酸性更强 ,说明虽然雾水中的离子浓度较雨水高得多 ,但大量的离子成分中存在更多的缓冲物质 ,比如说NH+ 4 和Ca2 + 。雾水中的Ca2 + ,SO2 -4,Mg2 + 有明显的富集现象 ,南岭大瑶山的雾水主要受大陆环境和人类活动的影响。

Fog is an aerosol system composed of plenty suspended tiny water or ice crystal which have severe scatter effect on visible light causing obstacle to visibility. There are radiative fog, advection fog and frontal fog according to the formation reasons of fog. Dayaoshan is a main mountain in Nanling Mountain area where is the important interface of climates in China. The highway from Peking to Zhuhai cross the Dayaoshan, the height above sea level of road surface ascend from 200 m to 800 m,and then descend to 200 m, the topogranphy is very complicated, heavy fog occurs frequently. In Winter and Spring, the visibility less 500 m is over 37% according to hourly statistics, so there are good chances to collect fog water and analyse it's chemical compositions. Based on the fog-water data from December 1998 to January 1999,and February, March 2001,the chemical compositions of fog-water in heavy fog processes have been analyzed, especially for the ion concentration of fog-water and their sources in three typical heavy fog processes. The analyses show the frequency of acid fog reach 50%, and the harms caused by acid fog should not be neglected. All ion concentrations of fog-water in heavy fog processes are far higher than those in rainwater. Therefore, fog not only cause bad visibility, but also harm people's health due to its highly polluted particles. When fog occurs, the high concentration polluted ion compositions will stimulate mucous membrane of respiratory tract, causing respiratory disease. The chemical features are obviously different from different fog processes. The highest negative ion concentration in fog-water is SO 2- 4; following NO- 3, while the Ca 2+ and NH+ 4 are highest positiveion concentrations. Rain-water is more acid than fog-water, showing although ion concentrations of fog-water are far higher than those in rain-water, there are more cushioning substances in the large ion compositions of fog-water like NH+ 4 and Ca 2+. The Ca 2+, SO 2- 4and Mg 2+ are obviously enriched. The fog-water in Nanling Mountain is mainly influenced by mainland environment and human activities.