三峡库区消落区土壤重金属污染调查与评价

Investigation and Evaluation on Heavy Metal Pollution of Water-Level-Fluctuating Zone in Three Gorge Reservoir Area

通过对三峡重庆库区16个区县,183个土壤样品的分析,表明三峡库区消落区土壤重金属含量均达到国家土壤环境标准3级以上.其中Cu含量范围为10.7～80.2 mg/kg,均值为37.0 mg/kg;Pb含量范围为14.6～51.8 mg/kg,均值为29.3 mg/kg;Zn含量范围为47.5～93.3 mg/kg,均值为72.7 mg/kg;Cd含量范围为0.081～0.864 mg/kg,均值为0.321 mg/kg;Hg含量范围为0.032～0.204 mg/kg,均值为0.059 mg/kg;As含量范围为4.63～12.7 mg/kg,均值为8.65 mg/kg.Cu、Cd之间存在极显著正相关关系,其余各重金属之间相关性不明显,pH值对重金属含量的影响不大.三峡库区消落区土壤主要受Cd、Cu污染.通过系统聚类分析,土壤重金属有明显的地域分布,即水库上游区、中游区和下游区.

Analyzing 183 soil samples of 16 counties in Chongqing Three Gorges reservoir area,it showed content of soil heavy metal of water-level-fluctuating zone in Three Gorge reservoir area was better than soil environmental standard grade 3. The mean Cu content was 37.0 mg/kg,ranging from 10.7 to 80.2 mg/kg. The mean Pb content was 29.3 mg/kg,ranging from 14.6 to 51.8 mg/kg. The mean Zn was 72.7 mg/kg,ranging from 47.5 to 93.3 mg/kg. The mean Cd content was 0.321 mg/kg,ranging from 0.081 to 0.864 mg/kg. The mean Hg content was 0.059 mg/kg,ranging from 0.032 to 0.204 mg/kg. The mean As was 8.65 mg/kg,ranging from 4.63 to 12.7 mg/kg. There is a remarkable positive relation between Cu and Cd. The relativities among other heavy metals are not obvious. The effect of pH to heavy metals is small. The pollution type is Cu-Cd. By the method of system cluster,the distribution of soil heavy metal are regularity. It can he disparted three parts （upper, middle and down reaches）.