北京地区雨水中溶解态有机氯农药的特征及源解析

对2006年5月~2007年11月北京地区雨水中溶解态有机氯农药(OCPs)的组成特征进行分析并对其进行源解析.结果表明,DDTs、HCHs、七氯、氯丹、六氯苯、艾氏剂和狄氏剂7种OCPs被检出,其平均浓度分别为(6.66±4.99)ng/L,(10.30±12.39)ng/L,(2.62±1.87)ng/L,(6.54 ± 4.58)ng/L,(3.99±3.02)ng/L,(2.10±1.40)ng/L和(2.25±1.58)ng/L.OCPs的总浓度在研究期间内呈总体下降趋势,表明北京地区的OCPs污染得到了较好的控制.通过对特征化合物的解析发现,有疑似的林丹和三氯杀螨醇的输入源,各化合物之间显著的相关性说明OCPs的输入途径相似.雨水中的OCPs含量与温度不相关;与降雨量和相对湿度有弱的负相关性;其沉降通量与空气中污染物的浓度相关,与降水量相关性不显著.

Characteristics and sources of dissolved organochlorine pesticides in the rainwater in Beijing

Characteristics and sources of dissolved organochlorine pesticides (OCPs) in the rainwater in Beijing were analyzed. Seven kinds of OCPs were detectable from May 2006 to November 2007. Mean concentrations of HCHs, DDTs, heptachlor, chlordane, hexachlorobenzene, aldrin and dieldrin in the dissolved phase were (6.66 ± 4.99) ng/L, (10.30 ±12.39) ng/L, (2.62 ±1.87) ng/L, (6.54 ± 4.58) ng/L, (3.99 ±3.02)ng/L, (2.10 ±1.40) ng/L and (2.25 ± 1.58) ng/L, respectively. OCPs Contents decreased during the study period, indicating the previous controlling measurement taking effects. By analyzing the source, it was notable that there were still some possible inputs of γ-HCH and dicofol. Every compound detected had significant correlation with each others indicating the common source of OCPs in the rainwater in Beijing. The total concentration of OCPs had no correlation with the sampling temperature while had weak reverse correlations with the mount of precipitation and relative humidity. The deposition flux was significantly related to the concentrations of targets in the atmosphere while weakly to the mount of precipitation.