生态环境学报2017，Vol.26Issue(7)：1221-1227,7.DOI:10.16258/j.cnki.1674-5906.2017.07.019
宁东基地不同工业园区周边土壤重金属污染特征及其评价
Pollution Characteristics and Assessment of Heavy Metals in Soil of Different Industry Zones of Ningdong Base in Ningxia, China
摘要
Abstract
To understand the characteristics of heavy metals contamination in the soils around different industry zones of Ningdong Base, soil heavy metals (Cr, Cd, Pb, As and Hg) were investigated and tested, and the chemical speciation of Cr, Cd, Pb and Hg contents of soil samples, in which were above local background values, were analyzed by using Tessier sequential extraction procedure, subsequently, the pollution status and ecological risks of heavy metals in the soils of survey area were assessed by single factor pollution index, Nemerow integrated pollution index and Hankanson potential ecological risk index, which is to provide scientific theory basis for protecting soil environment and maintaining ecological system in Ningdong Base. The results showed that average contents of Cr, Cd, Pb, As and Hg in the soils of survey area were 63.26, 0.13, 21.11, 8.77 and 0.17 mg?kg-1, respectively, which were all lower than the threshold values of the secondary standard (pH>7.5) of "National Environmental Quality Standard for Soil" (GB 15618—1995) and A-level standard of "Environmental Quality Standard of Exhibition Sites for Soil (interim)" (HJ350—2007). But the average content of Cr, Cd, Pb and Hg was beyond the local background value, respectively, among them, there was little difference between the average content of Cr, Cd and Pb and the corresponding background value, while the average content of Hg was 8.5 times higher than the corresponding background value. Speciation analysis of heavy metals in the soils demonstrated that Cr and Hg were mainly in residual fraction, however, Cd and Pb were mainly in non-residual fraction (including: exchangeable fraction, carbonates fraction, Fe-Mn oxide fraction and organic combined fraction), which was about 65.09% and 66.05%, respectively. The average single factor pollution index and integrated pollution index indicated that the pollution degree of all heavy metal elements in soils were clean (safe) level, and the soil in the studied area showed no heavy metal pollution. Further, the potential ecological risk index revealed that the soil of the study area was in slightly potential ecological risk. Although the soils around different industry zones of Ningdong Base had little affects from the heavy metal pollution, because of the accumulation of Hg was obvious, and the non-residual fraction of Cd and Pb still had higher content and proportion in survey area, the impact of these three elements on soil environment of Ningdong Base should be paid attention as soon as possible.关键词
土壤重金属/污染特征/风险评价/宁东基地Key words
soil heavy metals/pollution characteristics/risk assessment/Ningdong Base分类
资源环境引用本文复制引用
罗成科,毕江涛,肖国举,张峰举..宁东基地不同工业园区周边土壤重金属污染特征及其评价[J].生态环境学报,2017,26(7):1221-1227,7.基金项目
宁夏科技支撑计划项目(2015KJHM26) （2015KJHM26）
