青海湖表层沉积物重金属富集特征及其来源  

Enrichment characteristics and sources of heavy metals in surface sediments of Qinghai Lake,Northwest China

作　　者：朱阳春[1,2] 陈学民[2] 伏小勇[2] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所,兰州730070 [2]兰州交通大学环境与市政工程学院,兰州730070

出　　处：《生态学杂志》2013年第7期1862-1869,共8页Chinese Journal of Ecology

基　　金：国家科技重大专项(2009ZX07106-001-001)资助

摘　　要：针对青海湖表层沉积物重金属分布特征,测定了湖区11个采样点99个样本表层(0～20 cm)沉积物中重金属Zn、Cu、Pb、Ni、Cr和Fe的含量,采用地累积指数和潜在生态危害指数评价重金属富集状况,并运用相关分析和因子分析对重金属来源进行了初步探讨。结果表明,旅游区采样点151码头(1#)和江西沟码头(4#)的Zn和Cu元素及布哈河(5#)Cr为轻度污染,其他样点未受重金属污染,所有样点潜在生态危害均为轻微程度,以旅游区码头的潜在生态危害综合评价最高;沉积物中Cr、Fe和TOC存在显著相关性,且在因子1(内源因子)中占绝对负荷,其来源主要与沉积母质有关。此外,入湖河流也带入一定量的Cr元素;Pb和Zn与其他元素相关性较差,分别反映因子2(农业生产活动因子)和因子3(旅游交通排放因子)的迁移转化规律,其来源与人类活动有关;表层沉积物中Cu的积累与内源因子、农业和旅游排放因子均有关;Ni的分布特征主要受内源因子和旅游交通排放因子的影响。本研究表明,青海湖表层沉积物重金属污染及潜在生态危害较轻,其来源除内源因子外,还与湖区农业活动及旅游交通排放等人为因素有关。Aiming at the distribution characteristics of heavy metals in surface sediments of Qinghai Lake, 99 surface （0-20 cm） sediment samples were collected from 11 plots to measure the heavy metals （Zn, Cu, Pb, Ni, Cr, and Fe） contents. Geo-accumulation index and potential ecological risk index were adopted to evaluate the enrichment status of these heavy metals, and correlation analysis and factor analysis were conducted to approach the sources of these heavy metals. At tourist sites （dock 151 and Jiangxigou dock）, surface sediments were slightly polluted by Zn and Cu; in Buha River, surface sediments were slightly polluted by Cr; while in the other plots, no pollution was observed. All the plots had a slight potential ecological risk. There existed significant positive correlations between the Cr, Fe, and TOC in the sediments. The Cr and Fe played significant roles in factor one （endogenous factor）, and were mainly from sedimentary parent materials. The river water into the Lake also played an important role in Cr input. Both Pb and Zn had weak correlations with the other heavy metals, which represented the transferring and transformation patterns of factor two （agricultural activity） and factor three （tourist and traffic emission factors）. The Pb and Zn were mainly affected by human activities. The Cu accumulation in surface sediments was related with endogenous, agricultural, and tourism emission factors. The Ni distribution was mainly affected by endogenous factors and tourist and traffic emission factors. Our results suggested that the heavy metals pollution and its potential ecological risk of surface sediments in Qinghai Lake were slight. In addition to endogenous factor, the agricultural activities around the Lake and the tourist and traffic emissions contributed to the pollution sources of the heavy metals.

关 键 词：青海湖 沉积物 重金属 来源 

分 类 号：X524[环境科学与工程—环境工程]