2005―2006年间粤西云浮市大气降水化学特征

Chemical Composition of Precipitation at Yunfu City in Western Guangdong during 2005―2006

对2005―2006年间在粤西云浮市采集到的40场降水样品进行降水化学分析。结果表明,降水离子的平均浓度为730.62μeq/L,高于云南丽江、青海瓦里关山、香港、广东广州和鹤山等地,大气污染比较严重;降水中主要阳离子成分是Ca2+和NH4+,阴离子成分是SO42-和NO3-,共占离子总浓度的83﹪;离子浓度高值出现在降水偏少的汛期过渡期,低值则发生在降水丰沛的前汛期、主汛期和台风雨期;云浮降水离子浓度受地壳来源、工业交通污染影响较大,海洋源影响较小。

A total of 40 rainwater samples were collected to analysis the chemical composition of the atmospheric precipitation at Yunfu City in western Guangdong during 2005-2006. The total average ion concentration of the samples is 730.62 ueq/L, and much higher than that of the other stations such as Lijiang of Yunnan Province, Waliguan Mountain in Qinghai Province, Hong Kong, Guangzhou and Heshan of Guangdong Province, which shows that the atmosphere has been strongly polluted. The major elements are Ca^2＋ and NH^4＋ for cations and SO4^2- and NO^3- for anions, which accounts for 83 % to the total ion concentration. The higher ion concentration values are found in the transitional period between the flood seasons, where the rainwater amounts are low; and the lower values in flood seasons when the rainwater amounts are high. The ion concentrations at Yunfu station were influenced mostly by the crustal origin and industrial and transportation pollution; only a little marine contribution was observed.