生态与农村环境学报2017，Vol.33Issue(2)：135-141,7.DOI:10.11934/j.issn.1673-4831.2017.02.006
湘江中游江段沉积物重金属污染特征及生态风险评价
Characteristics and Potential Ecological Risk Assessment of Heavy Metal Pollution in the Sediments of Middle Reaches of Xiangjiang River
摘要
Abstract
In order to study characteristics and ecological risk of heavy metal pollution in the sediments of the middle reaches of Xiangjiang River,18 sediment samples were collected from 6 cross-sections of the Zhuzhou and Hengyang Sections of the river (3 samples per cross section) during the dry season for analysis of heavy metals and their total contents,chemical forms and bioavailabilities.Heavy metals pollution was analyzed by degree and graded with the geoaccumulation index method and single-factor index method,and effect of governance of the Xiangjiang River was evaluated.Results show as follows:(1) The contents of four typical heavy metals (Cd,Pb,Zn and Cu) were much higher than their respective background values in the soil of Hunan Province,being 83.1-1 178.7,4.46-15.9,2.88-16.1 and 3.35-6.22 times as high,respectively.On the whole,contents of the heavy metals rose gradually from the upper reaches to lower reaches;(2) Of the heavy metals in the sediment samples,the fraction of exchangeable form was rather low in proportion and the fraction of amorphous Fe-Mn oxides was in dominance,posing a high risk of secondary pollution;(3) The heavy metals in the sediments differed sharply in bioavailability.In the cross-sections at Xiawan Town and Songbai Town,the element the highest in bioavailability was Cu and in the other cross-sections,it was Cd;(4)According to Grade Ⅱ criteria ofthe China Environmental Quality Standard for Soils (GB 15618-1995),Cd,Pb,Zn and Cu all exceeded the threshold values,with Cd in particular,which reached the severe-extremely severe level;and (5) After years of comprehensive pollution control,heavy metal pollution in the sediment of the river has been lowered by a certain degree and hence their ecological risks.关键词
湘江中游/沉积物/重金属污染/生态风险Key words
the middle reaches of Xiangjiang River/sediments/heavy metal pollution/ecological risk分类
资源环境引用本文复制引用
刘俊,朱允华,胡劲松,彭国文,谢红艳,李志良,彭翠英..湘江中游江段沉积物重金属污染特征及生态风险评价[J].生态与农村环境学报,2017,33(2):135-141,7.基金项目
湖南省教育厅重点项目(15A168) （15A168）
国家自然科学基金(51574152) （51574152）
