2013 年春季华南师范大学石牌校区大气冷凝水的化学特征与来源

通过人工制冷的方法收集2013 年华南师范大学石牌校区大气冷凝水52 个样品，对其进行pH 值和阴阳离子分析。结果表明：2013 年春季石牌校区绝大多数冷凝水样品的pH 值分布范围为5.00~6.47，平均值为5.97，已不属于酸雨。冷凝水的阴阳离子总质量浓度（TDS）介于57.87~484.38 μeq/L 之间，平均值为154.53 μeq/L；各离子质量浓度高低依次为2-4 SO ＞Ca2+＞ -3 NO ＞Na+＞Cl-＞NO2-＞Mg2+≈K+＞F-。石牌校区冷凝水的这种离子质量浓度分布特征显示：其清洁程度较优于2011 年春季该校区和同期上海大气冷凝水，而较差于云南丽江的大气降水，与广东鹤山和青海瓦里关山等地的大气降水相当。其污染来源除部分属自然源外，还主要与建筑活动、工业生产、汽车尾气等人类活动等有密切关系。

Chemical Composition and Sources of the Artificial-Harvesting Dew Water at the Shipai Campus,South China Normal University,during the Spring of 2013

During the spring of 2013, for investigating the atmospheric environment, 52 samples of “artificial-harvesting dew water”, which was the dew artificially condensed from vapour, were collected at the Shipai campus of South China Normal University in Guangzhou. The measurement of pH values and ion concentrations of the samples shows that: 1) most of the samples had pH values ranging from 5.00-6.47 with an average of 5.97, indicating they were not of severe acid rain status; 2) The ion concentrations (μeq/L) of the samples in a decreasing order was 2-4 SO > Ca2+> 3 NO? > Na+> Cl-> 2 NO? > Mg2+ ≈ K+> F-. The range of total ion concentrations (TDS) was from 57.87-484.38 μeq/L with an average of 154.53 μeq/L. The characteristics of such pH values and ion concentrations indicate that the degree of cleaning was equal to that of the samples of atmospheric precipitation collected in Heshan (Guangdong Province) and Waliguanshan (Qinghai Province), and was better than that of the samples of atmospheric precipitation collected at the Shipai campus of Guangzhou and at a campus of Shanghai in the spring of 2011, but it was worse than that of Lijiang (Yunnan Province). The pollution sources were mainly anthropogenic ones, such as the airborne dust of building, combustion of coal and oil, etc.