骆马湖现代沉积物^(137)Cs和^(210)Pb_(ex)的测定分析与环境指示意义  

Determination and Environmental Implications of ^(137)Cs and ^(210)Pb_(ex) in Modern Sediment from Luoma Lake

作　　者：李文博[1] 林建宇 周强 王兆德[2] 许伟伟[1] 许迪 任静华[1] LI Wen-bo;LIN Jian-yu;ZHOU Qiang;WANG Zhao-de;XU Wei-wei;XU Di;REN Jing-hua(Technology Innovation Center of Ecological Monitoring&Restoration Project on Land(Arable),MNR Geological Survey of Jiangsu Province,Nanjing,Jiangsu 210018,China;Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences,Nanjing,Jiangsu 210007,China)

机构地区：[1]自然资源部国土(耕地)生态监测与修复工程技术创新中心,江苏省地质调查研究院,江苏南京210018 [2]中国科学院南京地理与湖泊研究所,江苏南京210007

出　　处：《环境监测管理与技术》2021年第5期41-45,共5页The Administration and Technique of Environmental Monitoring

基　　金：江苏省自然科学基金资助项目(BK20171075);省级地质勘查专项基金资助项目(苏财建[2017]160号)。

摘　　要：选取骆马湖进湖口、湖中心和出湖口3个位置的沉积物柱芯样品,采用放射性核素^(137)Cs、^(210)Pb_(ex)纪年技术定年,对其垂向分布特征及沉积速率指标变化对比分析,并测定沉积物中重金属垂直剖面分布。结果表明:^(137)Cs数值较低,不足以建立^(137)Cs计年时标;^(210)Pb_(ex)比活度随深度增加大致呈指数降低,采用^(210)Pb_(ex) CIC模式计算获得3个采样点的平均沉积速率及对应的沉积年代区间,进湖口相比湖中心和出湖口沉积速率较低,这与人为活动和水流因素有关;近50年来,骆马湖重金属污染物蓄积峰值总体出现在1975—1977年及1989—1994年两个时期,在2008年之后重金属的蓄积特征呈现逐渐增加趋势。The sediment core samples from 3 positions of Luoma lake inlet,center and outlet were dated by radionuclide ^(137)Cs and ^(210)Pb_(ex) dating method,the vertical distribution characteristics and the change of sedimentation rate index were compared and analyzed,the vertical profile distribution of heavy metals in the sediment were measured.The results showed that the value of ^(137)Cs was too low to be as dating marker.The specific activity of ^(210)Pb_(ex) decreased approximately exponentially with the increase in depth.The average deposition rate and the corresponding deposition age interval in the 3 positions were calculated by ^(210)Pb_(ex) CIC model.The sedimentation rate in the lake inlet was lower than that in the center or outlet.This was related with human activities and water erosion.In the past 50 years,the peak accumulation of heavy metal pollutants in Luoma Lake occurred generally in the two periods of 1975—1977 and 1989—1994,and the accumulation has been increasing since 2008.

关 键 词：^(137)Cs ^(210)Pb_(ex) 重金属 沉积速率 现代沉积物 骆马湖 

分 类 号：P597.3[天文地球—地球化学] X524[天文地球—地质学]