中文摘要：

为深入研究广州城区的大气环境质量,于2011年春季在华南师范大学石牌校区采用人工冷凝方法采集了33个冷凝水样品,对其进行pH和阴阳离子分析,以探讨这些冷凝水的化学成分特征.结果表明,石牌校区绝大多数冷凝水样品的pH值分布范围为5.65～7.11（个别样品pH值为5.06）,平均值为6.45,显示其已不属于酸雨,这在一定程度上反映出过去10多年特别是广州为迎接2010年亚运会在城市大气环境污染治理方面取得了较好的成效.冷凝水的阴阳离子总浓度（TDS）介于195.96～1267.76μeq·L^-1之间,平均为395.46μeq·L^-1;各离子浓度高低依次为Ca^2＋、SO4^2-、NH4^＋、Cl^-、Na^＋、NO3^-、Mg^2＋、K^＋、NO2^-、F^-.石牌校区冷凝水的这种离子浓度分布特征指示,其清洁程度差于香港、广东鹤山、云南丽江、青海瓦里关山等地的大气降水,而优于同期采集的石牌校区大气降水;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.

英文摘要：

During the spring of 2011, 33 samples of ＂artificial-harvesting dew water＂, which was the dew artificially condensed from vapour, were collected at Shipai campus of South China Normal University in Guangzhou. The measurement of pH values and ion concentrations of the samples showed that 1 apart from one sample of 5.06, most of the samples had high pH values ranging from 5.65 to 7.11, with an average of 6.45. This indicated that the rain was not acidic and the improvement of air quality was significant.2 The ion concentrations （μeq·L-1） of the samples in a decreasing order were Ca^2＋, SO4^2-, NH4^＋, Cl^-, Na^＋, NO3^-, Mg^2＋, K^＋, NO2^-, and F^-. The range of total ion concentrations （TDS） was from 195.96 to 1267.76 μeq·L-1 with an average of 395.46 μeq·L-1. The characteristics of such pH values and ion concentrations indicated that the artificial-harvesting dew water was suffered from mild-moderate contamination with the cleaning degree worse than Hong Kong, Heshan of Guangdong, Lijiang of Yunnan and Waliguan Mountain of Qinghaibut better than the atmospheric precipitation samples collected at Shipai campus at the same time. The pollution sources were mainly anthropogenic, such as the airborne dust from building construction, combustion of coal and oil, etc.