基于Pb稳定同位素分析的海岸带生态保护关键区域识别

Identification of the critical coastal conservation areas with ecological significance based on Pb stable isotope signatures analysis

Pb稳定同位素分析可以精确确定Pb的来源,揭示Pb在空间上的潜在迁移过程,从而对目标区域实行精确的污染管理.研究采集了盐城海岸带12个样方点的表层(0~10 cm)土壤样品,每个样方点3~5个重复,采用等离子光谱质谱仪测定各土壤样品Pb的含量及Pb同位素组成(^(206)Pb、^(207)Pb、^(208)Pb).结果表明:研究区域土壤Pb含量平均值是背景值的1.7倍,参考国家土壤环境质量标准GB 15618—2008,研究区域受到较严重的Pb污染.分析表明,盐城海岸带土壤Pb污染源主要为局地污染源,包括江苏省射阳电厂、双灯纸业芦苇基地污水处理厂和王港闸华丰工业园.采用归一化植被指数(NDVI)和距离分析,通过计算筛选出了盐城海岸带应对主要压力源的关键格局.

Pb stable isotope signatures analysis can be used to identify its sources precisely and the spatial transportation process to achieve precise management of target areas. In this study, 12 sur- face （0-10 era） soil samples （3-5 replications for each site） were collected on the Yancheng coast. Pb isotopes （206pb, 207Pb and 208pb） and Pb contents were analyzed by inductively coupled plasma mass spectrometry. Results showed that the soil Pb contents were as high as 1.7 times of the background Pb content value. Referencing the national criteria of GB 1561g-2008, the study area was polluted by Pb to a relatively serious extent. The analysis indicated that main Pb sources of the area were local, including Sheyang Power Plant, Shuangdeng Paper Mill Sewage Plant, and Hua- feng industrial area near Wanggang. Based on the normalized difference vegetation index （NDVI） and distance analysis, we figured out the key patterns of Yancheng coast to cope with the press sources.