贵州锁黄仓湿地沉积物重金属空间分布及生态风险评价  

Spatial Distribution and Ecological Risk Assessment of Heavy Metals in Surface Sediments of Suohuangcang Wetland in Guizhou Province

作　　者：王柏淳 朱四喜[1] 赵斌 李武江 WANG Bai-chun;ZHU Si-xi;ZHAO Bin;LI Wu-jiang(Institute of Karst Wetland Ecology,Guizhou Minzu University&College of Eco-Environment Engineering,Guizhou Minzu University,Guiyang 550025,P.R.China)

机构地区：[1]贵州民族大学,喀斯特湿地生态研究中心/生态环境工程学院,贵州贵阳550025

出　　处：《水生态学杂志》2021年第1期49-57,共9页Journal of Hydroecology

基　　金：贵州省科技厅科技支撑计划项目(No.黔科合支撑[2018]2807);国家自然科学基金项目(No.31560107)。

摘　　要：以贵州锁黄仓湿地表层沉积物为研究对象,利用空间插值分析、主成分分析与相关性分析方法,研究沉积物中镉(Cr)、镍(Ni)、锌(Zn)、砷(As)、铅(Pb)5种重金属元素含量的空间分布特征和来源情况,并通过Tomlinson污染负荷指数法和Hakanson潜在生态风险指数法进行生态风险评价,为锁黄仓湿地公园的生态安全以及有序发展提供基础数据。结果显示,Cr、Ni、Zn、As、Pb平均值分别为98.44、73.14、148.67、21.93、54.32 mg/kg,与土壤重金属背景值(95.90、51.20、99.50、20.00、35.20 mg/kg)相比较,5种重金属含量均偏高;而各重金属变异系数相对较小(13.94%~21.55%)。Cr、Ni、As之间以及Zn与Pb呈极显著正相关(P<0.01)。主成分分析中,第一主成分(A1)包括Cr、Ni和As,第二主成分(A2)包括Zn和Pb。锁黄仓表层沉积物重金属污染负荷指数为1.348,且上游(1.379)>下游(1.372)>中游(1.303),均属于"中等"污染程度。潜在生态风险评价表明,5种重金属潜在生态风险指数小于下限(RI=150),属于轻度生态污染。Cr、Ni和As的来源途径可能相同,主要受周边农业活动和环境影响;Zn和Pb具有相同输入源的可能性较大,主要受炼锌业和交通运输影响。研究表明,锁黄仓湿地受到中等程度的污染,但生态环境质量属于可控范围。Suohuangcang wetland is located downstream of Caohai National Nature Reserve in Guizhou Province. In this study, we analyzed the spatial distribution of five heavy metals(Cr, Ni, Zn, As and Pb) in surface sediments of Suohuangcang wetland and looked for common sources of heavy metal pollution using a combination of spatial interpolation analysis, principal component analysis and correlation analysis. The ecological risk of the heavy metals was assessed using the Tomlinson pollution load index and Hakanson potential ecological risk index. The objective was to provide basic data on environmental conditions to support efforts to protect Suohuangcang wetland. The wetland was divided into upstream, midstream and downstream regions and surface sediments were sampled at 22 sampling sites. The mean values of Cr, Ni, Zn, As and Pb were, respectively, 98.44, 73.14, 148.67, 21.93 and 54.32 mg/kg, all higher than background soil concentrations(95.90,51.20,99.50,20.00,35.20 mg/kg). Heavy metal levels, except for As, met the secondary standard of the national environmental quality standard. The variation coefficients of all five heavy metals were small(13.94%-21.55%), indicating a uniform spatial distribution of heavy metals among sampling sites. Positive correlations between Cr, Ni and As were highly significant(P<0.01), as was the correlation between Zn and Pb(P<0.01). Principle component analysis returned Cr, Ni and As as the first principal component(A1), and Zn and Pb as the second principal component(A2). The results indicate a common source of Cr, Ni and As pollution, primarily agricultural activities in the surrounding area, and a common source of Zn and Pb pollution, primarily zinc refining and transportation. The average pollution load index of heavy metals in the surface sediments was 1.348, indicating moderate pollution. The average pollution load index of heavy metals for the three regions followed the order: upstream(1.379), downstream(1.372) and midstream(1.303). The potential ecological risk indices of the five

关 键 词：锁黄仓湿地 沉积物 重金属 空间分布 生态风险 

分 类 号：X508[环境科学与工程—环境工程]